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,Coastal Zone Information COASTAL ZONE Center INFORMATION CENTE R 0 0 0 c-D 1, WW' 00 GB 459.4 0 .038 1974 A V. 1 c.2 ------------ A H. T. Odum D. I cope'RMd 1E. A. MCMELMn .r P.A,%pV V ASTAL ZONE INFORMATION CENTER edited by H. T. Odum University of Florida B. J. Copeland North Carolina State University at Raleigh E. A. McMahan University of North Carolina at Chapel I-Ell published by The Conservation Foundation Washington, D.C. in cooperation with National Oceanic and Atmospheric Administration Office of Coastal Environment VS Department of commerce ROAA coastal services Center flbrMoy 2234 South Hobson Avenue Ch"Ieston, sc 29405-241.3 The Conservation Foundation is a non- profit organization dedicated to encouraging human conduct to sustain and enrich life on earth. Since its fo un* ding in 194 8, it has attempted to provide intellectual leadership in the cause of wise management of the earth's resources. It'is now focusing increasing attention on one of the critical issues of the day-hQw to use wisely that most basic resource, the land itself. This publication is available as-a four- volume set from: Publications Department The Conservation Foundation 1717 Massachusetts Avenue, N.W. Washington, D.C. 20036 Price per set: $28.00 (if payment accompanies order) $30.00 (if billing is required) Published: June, 1974 ..."2 DIES& Cjbg- E I; OJ V342 ROL AL- lqw Coastal Ec 'ological Systems of the United the Conservation Foundation agreed to make" States was originally prepared for the Tederal this material available to a wider audience by Water Pollution Control 'Administration as reproducing the amended manuscript in the part of the National Estuarine Pollution Sur- most inexpensive way possible. vey -conducted in 1968 and 1969. It was the Those whose personal efforts merit recog- product of a group of scientists led by staff nition are Robert W. Knecht, director, and members of the University of North Carolina's Edward T. LaRoe, coastal ecologist, of the Institute of Marine Sciences. Its four volumes Office of Coastal Environment, who foresaw include a comprehensive survey of scientific the relevance of this work to the practical information through 1969, as well as a new needs of coastal zone management; Eugene T. system for the classification of coastal ecosys- Jensen and A. L. Wastler, of the U.S. Envi- tems. The manuscript was submitted to the ronmental Protection Agency, who arranged U.S. Environmental Protection Agency (which for the original study; and John Clark and absorbed the FWPCA in 1970), but was not Laura O'Sullivan of the Conservation Foun- published. dation, who, respectively, persuaded their or- The Conservation Foundation is now able ganization to publish this massive' work and to publish this work because of an assistance att6nded to the myEiad details of bringing it grant (Grant No. 04 3 -15 8-6 8) provided by the into print. National Oceanic and Atmospheric Adminis- tration's Office of Coastal Environment, which The Editors: is responsible for implementing the Coastal H. T. Odum, Zone Management Act of 1972. The,purpose University of Florida of the grant was to assist the Conservation B. J. Copeland, Foundation in preparing an amended version North Carolina State University of this comprehensive work for NOAA's pro- E. A. McMahan, gram use. Upon completion of that activity, University of North Carolina CONTENTS VOLUME ONE Introduction .................................................................. 1 Acknowledgement ............................................................... 4 Part I A Functional Classification of the Coastal Ecological Systems, H.T. Odum and B.J. Copeland ........................................ 5 Part II Foraminifera in Estuarine Classification, Maynard Nichols .......... 85 Part III A. Ecological Systems by State, B.J. Copeland and H.T. Odum ....... 104 B. Coastal Ecosystems of Alaska, C.P. McRoy and J.J. Goering ...... 124 Part IV General Recommendations ............................................ 132 Part V Chapters on Types of Ecological Systems A. Naturally Stressed Systems of Wide Latitudinal Range A-1. Rocky Sea Fronts and Intertidal Rocks, Staff ............. 152 A-2. High Energy Beaches,Rupert Riedl and Elizabeth A. McMahan ............................................... 180 A-3. High Velocity Ecosystems, Staff .......................... 252 A-4. Oscillating Temperature Channels and Canals, Staff ....... 271 A-5. Sedimentary Deltas, Bruce Nelson ......................... 278 A-6. Hypersaline Lagoons, B.J. Copeland and Scott W. Nixon ........................................... 312 A-7. Marine Blue-green Algal Mats, Larry Birke ................ 331 B. Natural Tropical Ecosystems of High Diversity B-1. -Mangrove Swamp Systems, Edward J. Kuenzler ............... 346 B-2. Coral Reefs, Louis DiSalvo and H.T. Odum ................. 372 B-3. Tropical Marine Meadows, H.T. Odum ....................... 442 B-4. Tropical Inshore Plankton Systems, James A. Marsh, Jr .... 488 B-5. Tropical Blue-Water Coasts, W.P. Odum. and John J. Walsh ............................................ K4 CONTENTS OF OTHER VOLUMES VOLUME TWO: C. Natural Temperate Ecosystems with Seasonal Programming VOLUME THREE: D. Natural Arctic Ecosystems with Ice Stress E. Emerging New Systems Associated with Man F. Migrating Subsystems VOLUME FOUR: Bibliography and Place Index INTRODUCTTnN The estuaries of the United States have always been a major resource in developIrient of America's economy, culture, and way of life. In the severe first winters'in New England the natural storages of food in clams and mussels provided critical foods to the early pilgrim colony. Most of the early pioneer cultures were nurtured by the foods and organized by the transportation pathways; provided by the tidewaters. Now in the twentieth century, the spread of urban civilization is including the estuaries, alter- nating cities with'wilderness areas in new designs for the planet earth. The new patterns involve wastes, dredging, and industrial uses of the bays which are changing nature so fast that our comprehension is badly lagging in spite of accelerating-efforts at scientific studies of estuarine science. Thus in 1968 the Congress of the United States has called for summaries of the status of knowledge of the estuaries pertinent to the planning of management and further.study. The Need for Organizing Knowledge of Estuaries by Type Following many years of studies of the coastal peas by universities, state government organizations and federal laboratories, the information dispersed in papers, books, reports, and documents is now vast, much of it in local sources outside the mainstream of national consideration and plan- ning. Without some new ways of organizing our knowledge and plans, no individuals can any longer encompass the knowledge,pertinent to management of the resources of a single state. Discoveries of relationships in estuaries on the Pacific coastmay be the answe-.@ to problems developing on the Atlantic coast and vice versa. Inadequate communication results in part from the difficulty of recognizing common features of coastal systems that seem to be different. Some means is needed for organizing-the knowledge according to a natural classification of estuaries, one that groups together estuaries with similar responses to disturbance, planning, or management. In recent efforts to describe the estuaries of America, 893 groups of estuaries have been listed. This is too many to consider individually as, if they were separate phenomena. Although each system has some properties unique and different, many have common similarities in their basic processes, which allow them to be grouped into types. Whereas studies of single species, single chemical processes, single geological features and single processes of a physical nature have been useful and often rigorous, the.behavior of an estuary depends on the total interaction of all the chemical cycles, water. circulations, and species behaviors. It is the whole system phenomena that state departments responsible for estuarine resources must consider. Perhaps it is in the'systems study of the overall performance that theie'is hope for prediction and management. The developing science of Ecology is the study of ecological systems (ecosystems) such as forests, lakes, and estuaries, and it is the realm of this science to provide natural ways to group the systems. 2 Man, A Component in Nature In the ecological approach to environmental systems man's role is con- sidere8 as an integral part of nature. An ecological system has inputs and outputs. It processes materials and energies within organizational patterns of water current, chemical processes, living components, and man's uses and wastes. Whether the system is a tiny balanced aquarium or the huge bio- sphere of the whole surface of the earth, all the users and processors of materials and energy are part. In the same sense urban man is now becoming a part of the coastal systems, often dominating the chemical processes as well as the fishes and microscopic plankton. Where the effective organiza- tion of processes breaks down, it may be man'who reaps disastrous results. Any classification of estuarine systems must include ancient types that pre- ceded man and that remain in wilderness areas as well as new patterns associ- atled with estfiaries newly disturbed by man. Part I presents 48 ecosystem types as a beginning. Others will probably be added 'as our knowledge pro- gresses. Estuary or Coastal System? In one sense, the word estuary may mean partially enclosed bodies of marine water such as lagoons, river mouths, and bays. The problems in management of our coastal seas and seacoasts, however, include the beaches, the intertidal rocks, mud flats, the coastal waters among island archi- pelagos, zones of the open sea waters along open shorelines, and other con- figurations which might not fit under the word estuary. America's need and the mission called for by Congress is clearly to organize our knowledge of all the ecological systems of the coast. Thus for this effort we deal with all the coastal systems where man's culture is or soon will be interacting with the sea. Usually, large estuarine bodies of water contain more than one ecological system or subsystem. It is the ecosystems rather than the estuarine water bodies that are discussed and classified here. Pollution and other Disturbances by Man The influences of man are presented in our report in two-ways. If the influence by man is not sufficiently large to distort the formerly natural ecological system into an unrecognizable structure and type, the disturbance factor is described and documented by the author reporting the story on that type of ecological system. If the energy sources or stresses involved with man's special'influence are so large as to predominate and in effect create a new type of system, this influence is recognized as oneof the emerging new types of ecological systems self-designing its relationship to man. These are found in the final group of systems (E). Organization of the Report Efforts have been made before to classify estuaries according to ecological principles and in Part I we build our classification on these earlier:beginnings, although we broaden the basis using theories of energy control. For a classification to be useful, it must serve to condense knowledge, to generalize, to aid teaching, to simplify planning for manage- ment, and lead to progress. It should not deal with only one geological structure, water flow, organism, etc. Once recognized, however, the types of systems may be mapped according to the distribution of indicator organisms such as the foraminifera, as described by Nichols in Part II. The presence of small skeletal-bearing organisms allows cores of sediment to be studied as a record of former systems. For each type of system that we define here, there follows a chapter summarizing its usual structures and processes. Bibliographic references are cited by system. Some are also cited by state. If estuaries have sometimes been handled in the past without adequate thought for overall system properties, a classification may help to guide future programs into a more rational organization. If the populations and properties of a coastal ecological system require management of the whole, ,a recognition of the main types of systems should help to eliminate efforts to deal one at a time with one species, one problem, or one component lo- cality. The main function of our report is to identify, characterize, and document some examples of each important type of coastal ecosystem. Remarks pertaining to individual states in Part III suggest the distribution of system types and their manner of application. However, there remains the need for separate studies in each state to map and designate-types in each estuary. Part IV has the report's overall recommendations concerning further study and management of the coastal ecosystems. Part,V has chapters on e *ach type of system. Knowledge about an eco- logical system can be introduced under 5 headings: 1. Summary of Components by Name, Mass, Number 2. Vertical Patterns 3. Horizontal Patterns 4. Flow Pathways 5. Temporal Patterns However styles and order of presentation of material by the various authors vary. Where a specialist was not available to supply a chapter, the editors have provided a substitution. Part VI is'the bibliography arranged alphabetically with pertinent state or locality indicated. Theletter code (the same as,that used in the table of contents) identifies references pertinent to a system type. In- cluded separately is a bibliography of estuarine bibliographies. Systems Analysis and Simulation Although estuarine science is only now entering the simulation phase, data on components and structure (items 1-4 above) provide means for simu- lating with computer programs that give the temporal consequence (item 5) of the structural patterns of species and chemical concentrations. If the com- puter simulation produces a temporal pattern in the system's'behavior that matches the observed pattern with time, then one has some evidence that the component theories of the behavioral interactions of the parts built into the program are applicable to the real one with some utility for prediction, for experimental testing, and for incorporation into a harmonious pattern of man's newest civilization. Its use in systems modeling is one reason for this effort to reorganize estuarine knowledge, recognizing a relatively few kinds of coastal systems, each of which can be simulated. With realistic simula- tion, rapid testing of expensive propositions with computer models may be arranged before tampering with the great estuaries themselves. ACKNOWLEDGMENT The Department of Zoology, the Department of Environmental Science and Engineering, the Marine Science Curriculum of the University of North Carolina, and the Marine Science Institute of the University of Texas collaborated with local support. We are grateful to the many scientists and resource managers in the coastal-states who responded to our mission, participating in the discussions of estuarine typing that were held in each state in the autumn of 1968. Mr. David Howells of N. C. arranged state interviews through the Water Res@purces Institutes. Ass 'istants on the project were: Kirsten Canoy, Joyce Shields, Ann Rogers, Henry N. McKellar, Richard Chalcraft, Kenneth Perez, David Bridges, Frances Dickens, G. M. McClain, Glenda'Sommers, D. W. Stanley, D. J. Yates., and Jesse Edwards* Jr& 5 Part I A FUNCTIONAL CLASSIFICATION OF THE COASTAL SYSTEMS OF THE UNITED STATES Ho T. Odum The University of North Carolina Chapel Hill 28514 B. J. Copeland The University of Texas Port Aransas 78373 INTRODUCTION It is an intuitive belief among marine scientists that each estuary and coastal system isunique and different., probably because there are so many possible combinations of important factors of geology., climate, tide and history that identical combinations are improbable. However., similar- ities do exist even among estuaries widely separated on op2osite coasts of the United States, so that it may be possible to classify the hundreds of estuaries into a relatively few types. We propose herewith a classifi- cation of the coastal systems of the United States according to the most prominent processes dominating the functional activity of the system. To clarify concepts and terminology we will first describe briefly the character- istics of any ecological system. After reviewing some previous efforts at estuarine classification,' we will present the proposed theory of classifteatior based on dominant energy flows. It is a basis that includes biological,, geological, chemical and physical classification factors, energy being a common denominator. An ecological system consists of populations of organisms, flaws of va,ter,, invisible pathways of cycling chemical elements and various organizational mechanisms vhich cause the parts to be inter-related. A bed of underwater eelgrass, with producing plants, micro-organisms and animals, is an ecological system. So is a bay in which water circulates and indigenous microscopic planktonic organisms develop., exchanging minerals from the bottom to the top in continual flows. Wherever there arespecial conditions,, the marvelous self-designing property of ecological systems produces special adaptations, chaxacteristic species of clams and fish and properties that are uniquely characteristic of that special condition. In the tropics there are coral reefs and in the Arctic there are systems that are adapted to ice and icy waters. Where the conditions pulse., the patterns and programs of the ecological system may pulse in response. Because conditions are,never exactly the same., the systems which develop are all unique,, but there are similarities that may form the basis for grouping and classification. classification is necessary in the affairs of man,, for vhere information is diverse and extensive the limits of the human mind require categories and simplified summaries for comprehension. The knowledge and publications on estuariesaxe so vast that clear perspectives are sometimes drowned in data. Patterns studied in one estuary may not be recognized as similar and re- curring in another. As the problems with preservation and development of estuaries become acute with expanding populations, there is increasing need for a classification that has meaning for planning and management. For the summaxies of the state of knowledge on estuaries requested by the Congress of the United States for 1968, a classification according to the principles of ecology may increase comprehension and simplify future planning. CHARACTERISTICS OF ECOLOGICAL SYSTEMS The general characteristics of an ecological system may be illustrated by the diagrams in Figs. 1-5. The following is a theoretical discussion of the relationships of various system components. Visual Summary Diagram Perhaps the first step in summarizing an ecological system is to present a visual inventory of the main components of a system. Thus Fig. I is a diagram that gives a visual summary of principal species of animals and plants that constitute the main control structures of the flows and processes of a plankton system in a deep bay. In such a diagram., one simplifies by including those species and non-living structures that are most dominant (i.e., most important by weight per area). one includes principal swimming species and principal bottom consumers. If data are available one includes a graph on the average masses of principal components. Such inventory of components alone gives little idea of -the way the system works, but the presence of characteristic species with known special adaptations suggests the nature of the system. Thus, species are known that are character- istic of plankton life., bottom life, low salinities, wide ranges of stress.. low temperature, etc. The public has often been misled by concentrating their interest on large visible organisms, whereas the important issues of yield, stability and water quality are more concerned with maintaining an effective flow of energy and mineral cycles. The populations of larger animals tend to be switch feeders taking some of many inputs,, especially any flow that becomes excessive, and serving by their omnivorous role to even out the total energy flaw web while supporting themselves. Because of the phenomenon of converging food pathways into the larger animals., these animals may smooth out small local variations and thus are sometimes useful as indices to classifications of system types where overall management planning may be involved. Vertical Patterns In vertical aspect (Fig. 2) the ecosystem can be divided into main zones relative to light energy that enters the system from above. The upper zone, where photosynthesis of microscopic plankton algae occurs, is matked with a P for primary productive photosynthesis (a process that uses fertilizer, caxbon dioxide and mineral elements to make organic food for the rest of the food chains and at the same time releases oxygen). k4ckeral Fig.l. Components of a plankton- based ecological system. Fragliarla lhalassiothrix PerWnium, Fish that shepherd fish Ch-,wtel Pass fthi:oaotenia Coscinodiscus concinnus 7'halassiosie, A Gonia ulax Light using Phytoplankton,,microseopic Alewife Micro-organismsdecomposing wastes -.-ACV Plongatus Fish that eat zooplankton 4cortza Vft& of remora losvicornis Menhaden certro ages 0 S t Ypicus Phytoplankton -!Z2 eating zooplw*ton Sketches from Kriss(1963), Tait(1968), Thread Herring. - Breder(1948) rnm sun light organi storage I import Euphotic x art zone plant subsystem I cells P R R bsystern I cu- i with much of the zooplankton con umi rs I and swimming consumers import R Im ort Export p pool of nutrients for plant growth r Worm and clam flat subsystem Export R bottom consumers VERTICAL ZONES MINERAL CYCLE 00 N Fig. 2A. Vertical zones in an estuarine ecosystem showing photosynthetic production above and most of the respiratory consumption (R) below, the mineral cycle circulating plant nutrients upward and organic matter for food downward with the action of stirring waters and swimming animals. E 0 a C 94 A CRUISE I FALL 1951 CRUISE I I FALL 1951 0 C a CRUISE III WINTER 1952 0 0 C 9+ CRUISE IV SPRING 1952 a I E a C 04 8 CRUISE V SUMMER 1952 1, 0 0 C 0* 9@ CRUISE VI FAL L 1952 E D a C 0+ 8 CRUISE Vil WINTER 1`953 .If a C CRUISE Vill SPRING 1953 CRUISE Ix SUMMER 1953 NUMBER OF ANIMALS PER CUBIC ..METER 001 -0.1 1.0 - 10 In 10 - 100 M. 100 -250 01-1.0 @' ., .::: The vertical distribution of Neoniysis ame'@icana along the axis of the estuary The dashed line is the depth of the critical light intensity. The nearly vertical straight line is the 4%0 isohaline. Fig ZB. Lxample of a population of intermediate consumers(Mysid shrimps) retaining position in an estuary as waters flowin and out. Delaware River Estuary(Hulburt, 1957) 10 The Batts" -see. preponderance of preponderance of "atoms Cardium Typical appearance. The Kattegat. Denmark. Necoma hesula Mocoma bottice Mocoma calcorea. Cardium ciliat T The Mocoma calcarea-comm. Arctic seat MI ardium adult Cardium c"s t H @ a: ; @ Comm Ic comeb W Nye arenoria im Iess. .M A My* arenoria The Max4ma The Macoma "Osula Comm battica-comm. Pacific coast of USA. Boreal parts of and Canada. Scm Ea.sternAtiantic. Aranicola clopored 1. (Compiled from literature and own experience) \Arealcola marine on" be K.1 "Mi.the. -Dijgr@pn sho-zeing Ike parallelism between the Arctic, Ilse boreal, and the Northeast Pacific 'Macorna communities Dm,A-n by Poul H. Winther; P. Thorson dir., Orig. Fig. ZC. Substitution of species in parallel cOmmuniti8s ('iborson, 1957). Deeper down in the shade, the Consumption of organic food by animals, micro- organisms and plants (termed respiration) is exceeding photosynthesis,and the overall process reaction is the reverse. When organic food is consumed, oxygen is used and minerals and carbon dioxide are released to the water again. An effective ecosystem circulates the products of one zone or layer as inputs to the processes of the other either by using natural circulation processes'of the water motions or by supporting animal, plant and micirobiological organisms that accomplish the same result through expenditures of work in such living processes as swimming, pumping streams of water or concentrating chemicals. All contributing structures, such as the populations of living organisms partici- pating in the system, have to be maintained by expedditure of work. The respira- torv consumption of food and oxygen measures the magnitudes of work involved in self maintenance. The tasks of work are divided up among specialists. Whereas some organisms are specialized by their biological adaptations to start micro- scopic plant food through the food chains, others are adapted to process foods accumulated by small animal plankton (water tlea size) and still others (e.g., larger fishes) are adapted to cover lax'ge areas and perform distributional roles in consumption of foods and cycling of nutrients. The specialized tasks in the ecological systems are performed by different s ecies, and the 'p significance of variety in living organisms includes the separation and specialization of functions of particular adaptive value. In stratified systems where normal vertical circulation is limited by the stability of the tvo-layered stratification, the mechanism of vertical migrations by organisms is an adaptation for vertical circulation of food, minerals and work. Although these summarizing statements do not begin to convey the complexity of reactions of the many organisms participating in the living control processes, they suggest the contributions to the system as well as the self-serving roles of their activities. The presence of a species is tied not only to its own abilities to utilize the available inputs and outputs, but also to the presence of a life support system that provides the correct combinations. Both the components and the overall flows of energy must be maintained without shortages and excesses. If this balance of cycling fails, the system. is less effective in processing food energies and is subject to replacement either as a whole or by substitution of pE4ts. Horizontal Patterns The main energy flows in estuaxine systems have lateral dimensions in map [email protected] above (9.6 in Fig, 3), especially where there-are strong water currents that organize the populations into gyrals and integrate food and,consumers i:n@7ways that are regenerating and continuing. The horizontal patterns help show the organization of the pathways between the plants that must be spread.-out to catch the sunlight and the centers of consumption (the animal cities) where the regeneration of plant minerals occurs in concen- trated centers of activity.' In urban culture transportation does this, but 12 A BIOLOGICAL EVALUATION OF THE DELAWARE RIVER ESTUARY U N IV I It 5 1 TY 0 P DELAWARE MARINE LABORATORIES x: P. .. .. ...... Delaware Bay Scale in Miles .... ......... x 5 10 0 K ........... ............. ..... ...... ......................... MAJOR SHELLFISHERIES OYSTER BEDS NATURAL . ..... .. .. EMPLANTID BLUE CRASS POTTED DREDGED HARD CLAMS HAND & DREDGE .......... Fig. 3A. Some of the ecological subsystems of a lzrger estuarine system, Blue crabs participate I bottom subsystem and the main plankton system above (Shuster, 1959). 13 A. ESTUARINE PRODUCTIVITY ..SUMMARY OF NUTRIENT FLOW: NUTRIENTS COMING FROM AND THROUGH THE NUTRIENT BUILD-UP 1) AR E IN A FORM USABLE BY MICROSCOPIC FLOATING AREA PLANTSIN THE BAY REGION (2). UNUSED NUTRIENTS ARE BOUND INTO MARSH PLANT TISSUES (3) AND ARE "FED BACK" REGULARLY INTO THE SAY WATER BY BACTERIAL ACTIVITY AFTER THE DEATH OF THE PLANTS (4). THE RESULT OF THESE PHENOMENA IS A RELATIVELY EVEN CONCENTRATION OF NUTRIENTS IN THE BAY WAT E R(5). Nutrient build-up area Nutrient pothways,(width of arrows Indicates rel. TIdernafSheSr ative concentration) 2 4 A BIOLOGICAL EVALUATION OF THE DELAWARE RIVER ESTUARY UNIVERSITY OF DELAWARE MARINE LABORATORIES WS 1 .0 - 0 cc 0 0 ..A go .0- X77N 40 _j J 0.5 - us . . . . . . . . . .. . . . . .. . . . . . . . . .- . . . . . . . . . .. . . . . ce. . . .. . .. . . . . . . 96 0.0 a C B. THESE CURVES SHOW THE TREND IN AMOUNT OF NUTRIENTS IN THE DELAWARE RIVER AT LOCATIONS a. b, C AND d IN RELATION TO BIOLOGICAL OXYGEN DEMAND AND,LIGHT PENETRATION. TOTAL NITROGEN (-) INCREASES, STE P-WISE DOWN. STREAM AND TOTAL PHOSPHORUS (NOT SHOWN) PROBABLY HAS A LESS PRONOUNCED, BUT SIMILAR BUILD-UP. IF LIGHT PENETRATION INTO THE RIVER WATER WERE GREAT- ERP THE AMOUNT OF THESE NUTRIENTS WOULD DECREASE DOWNSTREAM Fig* 3B. Other subsystems in the Delaware Estuary SXBtGm- The dark k area is the oligohaline ecosystem (Shuster, 1959). 14 in aquatic coastal. systems it is often the wind and tidal current patterns that control the pattern of horizontal organization. By circulating mechanisms or by back and forth shifts of waters, the production process is coupled to the consumption process to give full function. Pathway Patterns The pathways for processing of food, minerals and work are dravn using pathway diagrams (Fig. 4). Here., it is the inputs and outputs that are ixaportant rather than the positions of the organisms in space. New work diagrams help to identify occupation roles of the principal species and to characterize the ways that a system is special in its fine tuning of per- formances in the work network. The energy flow diagram is one of the ways for showing the pathways for food., work, interactions of species, chemical cycles and the actions of man. In the general energy diagram in Fig. 4, awe indicated several kinds of energy sources by which potential energy capable of driving work processes enters from outside. In estuaries, the sun operating the plant production processes and the organic fuels entering vitb rivers are most important. Fig. 4 also indicates the energy drains in a system, As required by the laws of energetics, some potential energy disperses as unavailable heat at every step and this is indicated by the symbol resembling an arrow into the ground. Also leaving the system as energy drains are exports of potential energy as when fish are harvested, when they migrate out of the estuary or when., during decomposition., some organic matter is buried into the sed- iment deeply enough to be permanently out of the chemical processes of the estuary. A stress on an estuary is a process that drains energy. It can be either directly as with fish harvest, or indirectly as by diversion of energy sources that the bay would have received (e,g., when turbidity shades out the light or when some property injurious to life is added so that energies of surviving organisms are diverted into special work of repair replacement or into programming of speciaJL behavior required to adapt to the special property). Thus, for example, addibg salty brines to an estuary raises the energy cost of operating kidneys and maintaining a proper blood chemistry so that only a few special organisms with the equipment for this can adapt. Thus the energy diagram in Fig. 4 helps to identify the special energy inputs or stresses characteristic of an estuarine system while showing the main uses of this energy within the network of living and non- living components of the whole system. Temporal Patterns An ecological system also has its temporal characteristics according to the course of the day, the tidal cycle and the season. Since the combinations work A - B Inflo eg _organic A self-organizing 'Jprk 9f closing, reward work service the m2ne al cycles feedback loop. 3pecies Phy.sical circulation B does special work for A in proportion to its rfanic Bacter.* feeding on -A ma ter P oplankton zoopla o Large Carnivores Light Plankton- cogtr?l eating fish Of pro uc on b Dients returning nutr O'=tflow @Of organic matter Fig. 4. Simplified diagram of the flow of potential energy in an ecological system ultimately emerging as dispersed heat or export of potential energy., Species are grouped according to similar food sources. For symbols see Fig. 7. 16 of energy inflows and stresses in a given system are usually unique the adaptations of the organisms also form unique combi- nations tntsc provide for programming of the biological and chemical processes' so as to fit the energy timing. For example, the migration of many fishes and shrimp is programmed so that the demands on the system@s energy budget coincide with the seasonal pulse of available energy. The adaptation serves a dual purpose: it gives the species the best possible ccmDetitive position relative to alternative species that might occupythat role and it provides a hand-in-glove fit of the food chains to energy budgets so that the system of processing as a whole is regulated, stabilized and increased in overall effectiveness in its competition. In describing any estuarine ecosystem, some graphs of pattern with time axe essential., showing the timing of special energy sources of light and river flows, stresses such as severe temperature change and pollution, and the programs of adaptation such as reproduction of organisms or blooms during periods of maximum grovth. Figure 5 illustrates temporal patterns of energy'source, energy stress and internal programming. @ISTORICAL ROOTS OF ECOSYSTEM CLASS M CATION The classification of ecological systems according to overall types was a major ob4ective of the early ecologists and geographers starting in the last century. Under the phrases "plant formation" and "vegetation type" chaxacteristic plant associations were named on land to classify ecological systems relating vegetation to causative climatic factors. Classification of climates was related to the vegetation types as in a treatise by K6ppen (1933J although definitions were in terms of rainfall, temperature and other meterological properties. Soils were classified in a similar way. Sometimes the soil type was related to vegetation type and a soil map made by mappJmg the vegetation, Since soil of natural systems was developed by the ecological system and its pattern of productivity and mineral cycles, soil is really a subsystem of the vegetation and its processes. In forests and greaslands. anJmaJ axe small in relative weight but serve important control functions. The word "biame" was generated to describe the large overall classifications of systems recognizing the moving animal populations as a necessary part in addition to the vegetation and soils, The tundra., coniferous forest, the rain forest., etc. axe biomes found the world over in characteristic climatic zones. The disturbed systems of the land were usually related to agricultural use so that by typing the soil the existence of nev types of man-made systems were implied. Agricultural systems have also been recognized,, the soil sub- system being an important parto The mapping and typing of systems of the land has been a major part of resources use and management. The advanced-state of land classifications is represented by Phelford's (1963) summary of land ecosystems of North America., by Kelloggs(1967) classification' of soil types, and Lieth and Walter's (1967) Atlas of climatic types in relationship to vegetation. In lakes., typing was related to the main features of oxygen.. plankton, and main dissolved chemicals,, vhich were Often dependent on the creolocry of the lake region and the geomorphology of the lake-forming processes. The lake A 17 20 P + I-* eTo t a IR+E N Gross Photosynthesis following Light (P) 10 River Contribution' of Organic Matter I) < 0 B Larvae of Residents Load of from Storage Southbound 10 /Migrants 0 LLI 10 C Load of S.tocks Moving int6 Residents Estuarine Nursery 0 I -, I D 10 Bacterial Action following Temperature Cu rve 0 E eZ oo p la n k ton ,-Larger Animals Uj Phytoplankton--. Migration out F- -7T N71) J F M7 A M 'i J7A S o from St@orage., _bouTn Migr@ an Oig. 5. Diagrams representing hypotheses of complementary coupling of energy loids and energy sources in the course of a year in a temperate regime with spring river runoff. 18 was readily recognizable as a single system of circulating minerals and media binding the plankton and bottom animals into a single interdependant network (Nauman 1932). Lake typology methods were extensively applied to Northern Europe. The treatises on Limnology by Hutchinson (1957) 1967) provide general sumnaries. A detailed classification of American lakes as syste*ms has not been made, but Frey's Limnology of North America (1963) provides a'summary of the limnological studies by sts e. Streams reflect the characteristics of the drainage "gasinsderiving their solution properties from the rocks,. ground waters and land systems drainage. Streams were typed by chemical content and related to regional land type. The water supply papers of the U. S. Geological Survey extend principles set forth in Clarke's (1924) Data of Geochemistry. More recently states have attempted management classifications on the basis of waste present and disturbancee In lakes and streams, boundaries of the system are usually distinct at the contact with land. Identifying the boundaries of systems was not the difficult problem it is in the sea. In the sea, with its interconnecting water exchanges forming one giant oceanic system, typing of subsystems was much more difficult because the boundaries of component systems were not clear, the dominant chemical and biological processes were mainly invisible and the areas so vast. Since the sea animals do much of the work that plants do on land and the biome name seemed appropriate., Petersen (1913) in Europe and Shelford (1913) and Shelford and Towler (1925), using data from the sounds of Washington in the U. S..,attempted to extend the methods of terrestrial biome classification to estuaries. Examining the bottom animals and plants, they named the systems according to the one or two most abundant visible large animal species there. This now seems a reasonable approach where the bottom system is the focus of interest or is a characteristic part of the estuarine energy flaws and mineral cycles (e.g., with shallow eelgrass). Even when the estuary is dominated by plankton processes, the bottom animals may characterize the total estuarine process if diversities are synall and adapta- tions of plankton and bottom animals are both determined by similar factors such as salinity stress. Thus Parker (1959), using molluscs, and Phleger (1960a), using foraminifera, may be cited among those who followed Shelford in the use of bottom animals to characterize associations of estuaries with some success. These classifications allowed sediments in the geological record to be studied in terms of the ecological system at the time of their formation, a field called paleoecology. In high salinities and less stressed environments, Shelford's classification of bottom associations had less significance as a measure of the estuarine systems in which the association occurred. In the higher salinities, as in the open sea, there is a finely tuned division of labor among many slightly different specialized species. Each species may form animal cities of a few acres participating as a subsystem, filtering the water that passes as it circulates over much larger axeas6 becoming a giant 19 pool of nutrients and productive plankton. No one bottom association is dominating the processes of the overall circulating energy and mineral cycling system. By moving, the plankton would have more tendency to integrate the patterns over the larger area except that they are so small that they fluctuate and change with small temporal transients so that no one collection cen represent overall effects. The small plankton in the big systems also differentiates into patches, each with different species predominating. Shelford's bottom classification in the more stable waters of larger dimension does not cover enough of the subsystems to represent the main functional processes, although it may be valid for the.subgystem types of the bottom. As the site and circulation energy of a marine system gets larger, the size of the component functions may increase. A small sheltered basin may have ten species of bottom animals dispersed in heterogeneous groups do that a few dredge samples may give an adequate statistical representation of the.vhole system. In larger systems, however, such as the coastal continent- al shelves, the bottom is differentiated into many subsystems each dominated by one or two species locally predominating in vast masses over many acres; but no one sub-system really predominates when one considers the overall large, areas over which water slowly circulates in large gyrals. The sea systems of the open continental shelf allow the plankton to maintain some continuing patterns as they pass from one bottom subsystem type to another. In such 16rsze systems, classification of bottom subsystems species would have meaning only if it were done over the whole area of the water gyral and the frequency of sub-system types enumerated. We may cite works of Zenkevich (1963) among those attempting to characterize the open shelves and deeper bottoms. Whereas an acre of land lies much of its main energy flaw and mineral cycle self-contained, an acre.of marine bottom in deeper water is only a contributor ,to the larger energy and mineral cycling systems of the circulating water above. Shelford's effort to extend the bime concept to deeper Maxine waters did not recognize the nature and location of the main organizational energy flows in the vater*above or the mechanisms for holding ecosystems organized in moving water. Efforts to define biomes of the estuaries were more successful where organismb were specialized in adaptint to particular factor-dominated situations. Thus the Stephensons (19 9) and Doty (195T) characterized inter- tidal zonations of algae-, Shelford(1930) the barnacle zoneswhere adaptations to fluctuating water levels produce similar patterns. Pearse (1950) general- ized on the beach system of the world. Emery's book (1960) on the sea off southern California considers its subsystems although it stops short of systems analysis, Bullock (1958) shows the physiological temp erature-metabolism mechanisms that permit an adapted species to control its metabolism to a level matching the rates of food supply.of the niche. From these data we infer that crude adaptation is possible within one species, btit finely tunea adaptation is done by substitution of species because of the ecdnomy of saving on physiological machinery. Redgepeth (1957)(cha'ter 13) reviews early efforts at classifi- p . cation, shows similarity of northern and southern hemisphere associations, reviews efforts to invoke the history of the animald distributions to explain patterns, and following Louis Hutchins (1947) and others confirms the fact of species substitution with temperature regime. He does not recognize that ;-- ach species,must also find a characteristic energy role for which it is preadapted and attracts a positive feedback. The Treatise on Marine Ecology edited by Hedgepeth (1957) was organized by environmental type but few of the authors considered system requirements (such as mineral cycling perfor- 20 mance and. feedback reward work) as causal prerequisite for organization of a species into the surviving network (see Fig. 4, inset ). Thorson (1957) set forth a parellel communities conceDt. By recognizing suecies substitution in roles of specialization, he recognized relativelyfew types of bottom e,;o- systems. See, for example, Fig. 2C. chapman (1964) in his book on coastal vegetation uses chapter headings: rocky shores., algal vegetation (sections on Laminaxia beds and on intertidal brown algae)9, salt marshes, send dunes, shingl-e-YeRaMes, and coastal cliff vegetation. By recognizing the basic similarities in vegetation by environment, from world wide examination his presentation defines several of the types used in our classification. With fewer parameters to consider,, geologists, considering the sedimentary bottoms of modern estuaries as a guide to understanding the sedimentary Focks., studied mineral properties and grain sizes of sand,, silt and clay. Because high current and wave energies maintain.ihe [email protected] particles in suspension, the bottoms have grain size and density in pro .portion_@to the energies of water motion. An energy classification of sedimentary environments was developed, with beaches and bays being-classified appropriately. Efforts to relate animals and plants of these bottom@ to the sediments made sense when the common dependence of sediment and-plankton feeders on water motion was recognized. The magnitudes of energy flows ard clearly a useful basis of coastal classification in these studies and may be cited. Munk and saxgent (1954) determined horsepower@per foot of reef at Bikini Atoll as a morphogenetic factor in devel-opment of coral reef ecosystems. Sakou (1965) measured energies affecting the mor@hology of Hawaiian beaches. Schiffman (1965) shawedthe distribution of breaXing wave and current energies on a ' beach (Fig.&@- The difficulty with''these efforts as a general classification is that only one kind of energy flow was considered. Light energies and organic food flows were omitted. Fig 6B shows the.relation of current energy to sediment size and clam density. Also geological in origin are the classifications of estuarine land- forms according to the processes and types of landforming energy flaws. Rise and fall of the land relative to the sea, the previous actions of glaciers and the erosion of rivers provided'a classification of the estuarine basins (Johnson,1919). The accumulated'vork. of @rior energy flaws in forming estuarine structure was a basis for this classification which may be represented by theories of entropy control by Leopold and Langbein (1964). Whereas geological structures have a major role in controlling the continuing flaws of estuarine energy, they are not sufticiently determinative to serve as a classification of the ecological systems in the estuaries. Thus two basins of similar geomorphologic type may be entirely different if the tides or the chemical contents of the rivers differ. For physical oceanographers studying the water motions in the estuaries, the distribution of srlt and density of water was important. Pritchard (19526) classified estuaries according to salinity patterns and the role of rivers, evaporation,, depth and tidal energies in producing estuaries. He found well- mixed river-sea water blends, two-layered estuaries with salt wedge on the bottom, estuaries with salinity higher than the sea because of more evaporation than freshwater inflow and neutral estuaries having no net change in salinity of sea water while in the estuary. This classification by salinity summarizes the interaction in one respect of several- kinds of energy drive converging in the estuary, but it does not summarize all pertinent processes affecting 21 V=rry M\W. A W 0 2 1.51 Q5 15 1 Q5 GRAN SIZE 0 1AREAS (A. A, + An) E= T VELocrry r2F. LLJ SWASH ZONE TRANSITION SURF ZONE BREAKER ZONE ZOW- . . . . . . . .... . . Generalized bottom energy profile. 'Fig. 6A. Energy of moving water on a beach (Schiffman, 1965). Bottom type Current Mud Insignificant Sand-mud 0.1 knot mixtures Sand 0.2-0.5 k t Shell 0.6 - 1.0 knot 0 10 20 30 10 20 Average density Average density Relationship of the a%-erage density of individuals of llferccnaria inercenaria, the bottom type, and the current in Chincoteague Bay, Nfarylancl. (After H. W. Wells, 1957.) Fig. 6B. Action of current energy in control of sediment size and clam growth (Ager, 1963). 22 COASTAL ENERGY LEVELS Mad or a to Low High High Low .P -Coastal energy levels of the U. S. South Atlantic and Gulf of Mexico (Tanner, 1960). Fig. 6C. Classification of coastlines according to wave-current energies (Linton, 196-P), u1me 1'e Itot DRIDqr%r I too some 4r 03"_ 24, PACIFIC OCEAN 1@ftvft two 4 A coo ze 4 SAW :1A COOS BAY. OREGON 0 *"TWAL W" a Two MATS "nU NEAR LOWIM Low WATM cowroun "I" &L&co4L& _J43 *WN SAY. 5944. M. INS Map of Coos Bay showing location and extent of tide flats. Fig. 6D. Oregon estuary in which tidal energy measurement was made (Blanton, 1964). 2.20 23 528 Meters 2.00 1.801- 1.60 - Base velocity 55 cm /sec 10 cm sec 1.40 - C*jI 1.20 - E 1.00- (x W z T. 64 Meters W 0.80- 0.60- 0.40 0.20 0.00. -2 V 10 10 10 K ( ffiL) Energy spectra for high and low tidal velocities at the U. S. 10 1 bridge. Fig. 6EL The distribution of energy according to.sizO of eddy in Coos Bay, Oregon at two stages of the tide, data used in computing energy dissipation from the tide (Blanton, 1964). 24 ecosystems. For example, two estuaries with the same salinity and mixing pattern are entirely different ecologically if the nutrition of the river contribution is different or the seasonal timing of temperature is different. The salinity classification does not include enough-factors for general estuarine classia. fication. The use of differences between freshwater heads and tidal heads to get exchange coefficients is a means of using potential energy for estuarine classification (Urban and Masch 1966). Although this is only one type of energy influencing estuarine systems, it has been useful for engineering design and hydrographic modeling.. Blanton (1964) measured the energy dis1pation from the tide in an Oregon estuary (Coos Bay) (Fig. 6D, 6E). Another kind of classification is based on man's interaction with the estuary as part of the land system rather than on properties of the estuarine system alone. A practice of classifying estuaries as A, B, C, D., etc. according to quality of use was developed by governmental agencies to regulate the permissiveness regarding waste disposal. This pattern has been extended from stream into estuaries in many states. Often this usage ,classification,has been made for shores without regard to the unit of re- circulating water where such a classification might have some workability. Often the typing refers to safety for shellfishing in the presence of sanitary wastes containing fecal bacteria. Sanitaxy classifications probably provide some idea of the degree of outside nutrient fertilization. Use classifications are of little va3-ue for the management of marine systems for optimum benefits of a harmonious coupling of.Man and nature. The resource and use must make sense together. Where man's destructive use of the estuary becomes dominant, as with low quality classification (D) where harbors have received multiple wastes of many industries in high concentration, the typing may well characterize a new I'stinko" estuarine type. In general, however, the classi:fication makes no distinctions between kinds of ecologicalWstems, and thus provides no guide to the kinds of resource use possible. Our knowledge of estuaries should allow us to do much better and providea sounder ecological basis for estuarine management. All of these previous efforts at classification suffer from the same difficulty of including only part of the predominant phenomena and factors involved. Elsewhere in affairs of science and man, complexity of different processes have been amenable to unified consideration by the use of the concepts of energy flow. Energy is a great common denonimtor measuring processes of all kinds. Thus we attempt next to combine the roots of the historical contributions to classification through a general energy classification. 25 THEORETICAL BASIS FOR AN ENERGY CIASSIFICATION The classification by energy allows such different features of sys- tems as light, tide, pollution, fertilization, haxvests and thermal dagrada-@- tion to be considered under one common denominator, that of -potential energy flow. Different types of systems result when the energy flows are different in character, and the organisms that control the systems show these differ- ences in their adaptations and diversities. 0 'ur classification is given in Table 1. Consider some theoretical aspects of the system. Table 1: A classification of coastal ecological systems and sub- systems according to characteristic energy sources. Category 'Name of type Chaxacteristic energy source or stress A., Naturally stressed High Stress Energies systems of wide latituainal range A-1. Rocky sea fronts and in- breaking waves tertidal rocks A-2. High energy beaches breaking waves A-3. High velocity surfaces strong tidal currents A-4. Oscillating temperature shocks of extreme channels temperature range A-5. Sedimentary deltas High rate of sedimen- tation A-6. Hypersaline lagoons briny salinities A-7., Blue-green algal mats- temperature variation and low nighttime oxygen B. Natural tropical Light and Little Stress ecosystems of high diversity B-1. Mangroves light and tide B-2. Coral Reefs light and current B-3. Tropical Meadows light and current B-4. Tropical inshore organic supplements plankton B-5. Blue water coasts light and low nutrient 26 Table 1 (cont'd.) Category Name of type Characteristic energy source or stress C. Natural temperate eco- Sharp seasonal program- systems with seasonal ming and migrant stocks programming C-1. Tidepools spray in rocks, winter cold C-2. Bird and Mammal Islands bird and mammal colonies C-3. Iandlocked sea waters little tide, migrations C-4. Dbxshes lightly tidal regimes and winter cold C-5. Oyster reefs current and tide C-6. Worm and clam flats waves and current, intermittent flow C-7A. Temperate grass flats light and current C-7B. Shallow Salt Ponds small waves; light en- ergy concentrated in shallow zone C-8. Oligohaline systems saltwater shock zone, winter cold C-9. 1&-dium salinity plankton mixing intermediate estuary salinities with some stratification C-10. Sheltered and strati- geomorphological iso- fied estu6xy lation by sill C-11. Kelp beds swells, light and high salinity C-12A. Neutral embayments shelfwaters at the shore C-12B. Coastal Plankton eddies of larger oceanic systems D. Natural Arctic Eco- Winter ice, sharp mi- systems with ice grations and seasonal stress programming D-1. Glacial fiords icebergs D-2. Turbid outwash fiords outflow of turbid ice- water lens 27 Table 1 (cont'd.) Category Name of type Characteristic energy .Source or stress D-3A. Ice stressed coasts winter exposure to freezing D-3B, Inshore Arctic eco- ice, low light systems with ice stress D-4. sea ice and under-ice low light plankton E. Emerging new systems New but characteristic associated with man-made energy sources and/or stresses E-1. Sewage waste organic and inorganic enrichment E-2. Seafood wastes organic and inorganic enrichment E-3. Pesticides an organic poison E-4. Dredging spoil heavy sedimentation by E-5. Impoundment blocking of current E-6.. Thermal pollution high and variable temperature discharges E-7. Pulp mill waste wastes of wood processing E-8. Sugar cane waste organics, fibers, soils of sugar industry wastes E-9. Phosphate wastes wastes of phosphate min- ing E-10. Acid waters release or generation of low PH E-11. Oil shores petroleum spills E-12. Piling treated wood substrates E-13. Salina brine complex of salt. manufacture E-14. Brine pollution stress of high salt wastes and odd element ratios 28 Table 1 (cont'd.-) Category Name of type Characteristic energy source or stress E-15. @etrochemicals refinery and petro- chemical manufacturing wastes E-16. Radioactive stress radioactivity E-17. YLdtiple stress alternating stress of many kinds of wastes in drifting patches E-18. Artificial reef strong currents F. b1igrating subsys- Some energies taxed tems that organize from each system axeas In the presentations that follow, a principle of classification is used which gives recognition to whatever influence is most prominent whether it be physical, biological, geological or derived from the actions of nan. The common denominator for measuring the amount of influence is energy. All processes by man or by nature are measurable by the amounts of potential energy in Calories which have been passed through the system doing work. The kinds of energy that usually dominate the coastal systems are of three main types (Fig. 8A). 1. Light energy drives photosynthesis of the plants and supports the food chains that support biological populations. Where other energy sources are relatively minor, the light energy acting through plants so characterizes the system that it is appropriate to recognize the productive plant in the clas- sification@ Thus we have Eelgrass systems, Phytoplankton systems, Turtlegrass systems, Kelp beds, etc. 2. Organic fuels constitute a second regular energy source to the coastal ecosystems. Many rivers, for' example, carry loads of organic matter from the fields and forests which serves as the food for bacteria and higher animals. Some of these fuels are wastes from man's emerging system. Others axe entirely natural such as the organic matter from swamps or mangrove coasts. 3. Mechanical energy is the absorption of fluid momentum of the winds, waves and tides and is another environmental,-source of energy, which is responsi- ble for many of the phenomena of the system. A beach, for example, receives the pounding of incoming waves that so predominate the system that the sedimentation, the organismal adaptations and chemical phenomena ar& determined and coupled. 29 Often, when other energy flows axe dominant such as light-driven photosynthesis, the physical energy augmentB particular processes as an auxiliary source. Thus the turbulence of physical stirring serves to augment nutrient circulation, mak- ing special pumping mechanisms by organisms unnecessary, and allowing other prop- erties to be developed instead. Such differences are implemented by substitution of species. The flows of energy are channeled according to the biological, chemical and geological structures of the system that axe in turn maintained by-the sys- tem 'or introduced from the outside (and thus are energy sources). The sed.imen- tary structure of a beach is maintained by the properties of breaking waves. The patterns of plankton are maintained by circulation of waters and the behav- ioral responses of'the animals. Energy Flow Diagrams The representation of energy flows may be done with energy flow dia- grams (Fig. 8A, B) using the symbols in Fig. 7. Energy flows from potential energy storages (circles) or from external energy sources. All potential energy which does work must divert some of its flow into dispersed heat as shown by the, arrow-ground s'ymbol, which diagrams the second energy principle. External energy sources provide energy in programs that axe characteristic of the situation. The energy budgets of most estuarine systems are sketchily known sp that quanti- tative values are available in only a few cases. Certainly completion of the main features of the energy diagrams with quantitative data on flows and programs of input are developing understanding and among the first needs in management. Where a flow requires a second flow as in a chemical reaction, in a process incorporating essential,parts, in a process requiring work from a second source, etc., the second flow of energy passes into heat while making possible potential energy flow from the first source. This is indicated by the work gate symbol (pointed block). Such a symbol represents multiplication of two flows and the process of varying the force of one while holding the second constant provides a hyperbolic output response of the interaction. The quantitative as- pects of energy diagramming and other systems languages are not treated here ex- cept to show the relative dominance of particular flows that dominate the princi- ple classes of coastal systems. These diagrams may help to clarify verbal state- ments. A system is an organization of component participating parts and flows, and the diagrams help to clarify the organization of theseparts. Names Although dominant energy inflow should determine the classification as- signed to a system, narning of systems needs to be familiar, readily attached to our experiences and easily reme 'nbered., Names, therefore, are common English words which describe or are associated with the dominant energy influences. The quantitative accounting of the proportion of total phenomena including physical, chemical, biological, geological and man-made processes is energetic and may be diagrammed similarly. The flow of energy from potential energy into useful work is the great common denominator. 30 Energy network symbols A B c ENERGY SOURCE PASSIVE ENERGY HEAT SI.NK STORAGE D E F POTENTIAL PURE ENERGY WORK GATE GENERATING WORK RECEPTOR G H SELF-MAINTAINING PLANT ECONOMIC CONSUMER POPULATIONS TRANSACTOR POPULATION Fig. 7. Symbols of energy flow diagrams(Odum, 196Z) . Tid Circulation work W wave rec cli action of nutrients Plants CO? Consume anic otter Fig. 8A.- Three main sources of potential energy for estuarine ecosystems* Symbols are given in Figs 7* All + Energy So ces ECOSYSTEM microscole rdering Maintenance against thermal Energy degradation diverted Harvest and from ecosystem other forced losses Sum of stresses Sources of energy driving stresses In calories per day Switching work Fig, 8% Main sources of stress in estuarine ecosystems. Stress is defined as potential energy diversion or drain. 9 . 33 Boundaries The boundaries of an estuarine system may be the natural boundaries of a shore line if that shore encloses a system of components. Usually, how- ever, one system connects with another so that boundaries are,not sharp. There are usually flows from one system to another but it may be convenient to draw,a boundary when the cycling and organizational processes within the system are of greater magnitude than the input and output flows. Systems and Sub-Systems All systems are made up of sub-systems, lesser but recognizable units with their own characteristic flows and structures. A residential district is a subsystem of a city. A mud flat or a submerged grass bed are examples of subsystems of an estuary. Sometimes the type of,,system in one area is a major system but becomes a minor subsystem in some other area. Most partially-en- closed basins on the coasts are'not single systems for 'our purposesi but include recognizable sub-systems which require separate treatment for understanding and management. The coast lines of the United States have strings of systems and sub-systems alternating according to the external energy flows available at dif- ferent locations. Stress as Energy Drain When an energy flow drains structure and energy away from another flow it contributes to the character of that system, although it may be detrimental in the sense of eliminating structures and patterns that would have developed due to some other energy flow. For those conscious of biological properties, growths and populations, there are many energy flows of great severity that drain energies away from biological productions either by destructicn or by re- quiring defensive adaptive work by animals. Low diversities of organisms ac- company the development of special adaptations of the organisms that do main- tain a system. Whether positive or negative, energy flows are characterizing' the system. Pollutional actions are one of the many kinds of energy flows that may modify a systems structure and processing in special ways (Fig. 8B). Emergent New Systems Coupled to Man's Influence Emerging in response to dominant special new energy flows from man's civilization are characteristic complexes of organisms, chemical properties and geological parameters that constitute new estuarine systems. The characteristic patterns found when sewage is running into sea water or the complex near pulp mill outfalls axe examples of new systems that may be expected to reoccur when- ever an estuary is dominated by one of these special inputs due to man. T 'hese new systems have had little time to develop special organisms by evolution al- though the micro-organisms are capable of rapid mutation and selection. Through preadaptation, organisms may exist on earth in fresh or salt water which will find conditions of the new flow adequate and growth-promoting. The testing of the suitability of organisms to these new conditions is going on continuously by the trial and error of animal migrations without any aids from man. There is some reason to hope that one of our new pollution systems.which has inadequate process- 34 ing, cycling and order now may in time become a better self-controlled pattern as more organisms evolve or emigrate to develop the variety and specialists of the system. In Table 1 are recognized in the classification some of the emergent new systems where examples exist that provide evidence of special character. In defining the emergent new systems associated with new inflows from man, we do not necessarily indicate whether the new system is good or bad, such judgement being related to considerations such as the type of system displaced, the system of man and nature desired at that point and the meaning of the change for the survival of man. New disturbed systems which may seem harmful by displacing valuable natural systems, if knowledge develops, may be managed with additional controls towards some useful and beneficial purposes. In this report we seek only to recognize the controlling energy flows, base our classification on this natural basis and organize our knowledge therewith. 35 NET SOURCE-STRESS EITMIES AS A SCALE FCR ESTUARINE CLASSIFICATION In considering latitudinal and emerging ecosystem types., the presence of characteristic types is apparently related to the energy available for supporting special systems* Consider the following theoretical reasoning which underlies the classification of American estuaries* The following summarizes current ecological theorye Relation of Energy to Specialization and Diversity It is a well established principle in ecology that among populations of organisms of different species capable of exponential Yalthusian growth) if not organized in some way to prevent ccmpetition" one species will exclude the other* This is so because the one with an edge in reproductive rates will, under the conditions, feed back its resources into more individuals, gaining an ever widening supremacy in numbers and ability to use the resources in comparison to its competitor. Thus in various kinds of simple situations in laboratory or in disturbed situations in nature, competitive exclusion is the result* If, however, there are additional species that serve to regulate and control, if there are program of behavior built into the species involved, or if o1ther means such as specialization prevent competitive exclusions, then the pattern of many species is possible. There is diver- sification and specialization, and the system as a whole may have higher efficiencies in its total effect although energies are spent in the con- trolling and organizational process. Organization is thus measured ir x the control preventing competitive exclusion and permitting specialization* The amount of specialization and organization possible depends on the- energies available after stress and basic maintenance of a system is covered. Thus amy disturbances and stresses introduced by climate, fluctuation in external condition or actions of man serve to detract energies from that capable of developing organization and diversity, Competitive exclusion Increases and species diversity must decline. Diversity is thus useful as an index of the amount of stress whether natural, induced by pollution., or other influence* In one stress location a particular species may jWe- vail and a different one in another location, but both are possible only when there is less energy drain and enough remaining for organization to support both* The opportunity for a species, In ecological jargon, is called the niche, a term that refers.to the Input and output connections pro- vided by the system and to the role of the species which adapts to these inputs and outputs*, Hwe niches are possible with more energy beyond stress costs because more complex networks can be organized by energies spent on control mechanisms., In general, availability of energy for organization and diversity divides the flows of energy among many kinds of species so that there is little for any ones Thus, potentials for food harvest for man are not increased even though the total productivity of all the species tends to be large. Stresses often chw- 1 energies into high yields of a few products 36 which are succeeding in competitive exclusion. Where stress is high and diversity is Small,, the estuarine system tends to have a few dominants, to support large fisheries based on one or two specieso Because the system is'not finely tuned in adaptation, it tends to cover wide ranges in latitudes These systems tend to take human disturbance r6adily because of their specialization for change, rapid replacement and progra=Ltng for severityo The complex systems have great diversity of specialists for mineralizing various organic chemical substances of the ecosystem and from mants waste. A property of the diverse system is effective mineralization and water cleaning processing. Stresses that tend to reduce the diversity eliminate mach of this ability for diverse microbial and chemical pro- cessing by the organisms* Thus there is an inverse relationship of mineralization and food yield tendencies of ecosystems. Size, time and location of systems are also involved* If there is an isolated small estuarine system, it nay not have had the size and time to evolve independently as many kinds of species as it might support under the conditions of energy source and stress. If j, however,, species which have developed the same kinds of adaptation elsewhere can be moved in, there may be an increase in the diversity and organization possible. Particularly. in isoleved situations like Hawaii, there may be more simplicity than energies are capable of supporting* When systems are very small the pro- bability of re-6stablishment is smaller relative to probabilities of extinction due to normal fluctuations of small simple systems. The theory that the balance of energy of source'minus stress controls diversity suggests a pattern of different estuarine types represented in Fig. go On the hori- zontal axis is reTresented energy source and on the vertical axis energy stress (drains). Diversity and organization is highest where energy sources are high and stresses low as in many tropical situations or in many situations in oceanic temperate locations and least in arctic situationsy in areas of great salinity shifts,or in areas of large dis- turbance by pan. Diagram of IALtitude and Salinity Stress In estuaries, the stress-of the fluctuating salinity end latitudinal temperature shifts are main influences that operate to control diversities and the variety of ecosystem types. In Fig*10 the amount of salinity fluctuation is indicated on the horizontal axis and latitude is indicated on the vertical axis* High latitude has severe seasonal temperature changes for which surviving programs are necessarily adapto6de In general the higher latitudes have about half as nuch light energy per year to use towards maintaining structure as compared with the tropics so that the combination of less energy and more temperature stress allows less energy for speciali- zation and orgahizationo The section in the lower left with low stress from temperature and salinity has high diversities In each system and a high diversity of possible systems addpting each one in a finelytuned manner to local ciretun- stances so that there are many mcre kinds of sub-types, The upper right section of the diagram with high salinity variation is very low in species and tends 37 100- V 4@- Losing Storage E and structure Disturbed Eutrophy W Cn Beach ell- W Temperate z W Arctic Coral Deep Sea Reefs 100 ENERGY SOURCE, Cal/m2/day Stress I Ecosystem Fig* 9o Diagram for showing ecosystems as a function of their useful energy sources and detrimental stress. The space between the plotted point and the diagonal line is a measure of the energy for structure and diversity. 01 30-- Thermal Pollution .0 U; z < CC Cape Cod 15-61 Hypersoline 20-- Canal w a: D , N. Temperate <I- dea> Oligohaline a: V1, 10-- w Tropical Coral Reefs Oligohaline 10 20 30 40 to SALINITY RANGE, %0 Fig, 10, Graph of temperature and salinity ranges for diagraming stress and diversity of ecosystems. 39 to have only a few types. Typing is not only simpler, but. management planning may be more readily studied. Latitudinal Differentiation In systems in which.stress is large., the energies for finely tuned diversitylspecialization and organization do not exist and specialization of faunas with latitude do not develop* Thus in natural areas which have high 'wave energies like beaches., in sharply fluctuating salinity situations., or in situations of extreme-pollution., latitudinal differencesdisappear as the adapted differentiated systems are displaced*, Highly stressed systems can therefore be classed according to the stresses to 'which their pompo- nents must adapt., but not according to latitude* One of the most striking examples is the prevalence of Crassotrea virginica (the eastern oyster) reef system in Pearl Harbor, Hawaii where sharp s sses from salinity fluctuation and from pollution bring in the general stressed pattern system of the east coast of the United States (Figs 3.1-13). Another is the severe fluctuation of temperature in the Cape Cod Canal which simplifies attached conmunitiesproducing the ubiquitous green algal associations that one finds also in polluted harbors at San Juan., Puerto Rico.. or the naturally stressed Intertidal zones of Venezuela (See Chapter A-1) or Alaska (Hubbard,, 1968)* Thus the first main division of our- classification consists of natural systems of wide latitudinal distribution associated with high stress energies of natural origin. For similar reasons we group most of the emerging new systan associated with new kinds of stress from man also without much latitudinal variation. In the man-stressed systems., there is an additional factor of inadequate time for evolution of adapted specialistse As one moves away from the high energy beaches and salinity@ shocked river mouths.. the stress diminishes and the differentiation is with latitude and temperature programing. The eastern United States in general has severe fluctuations of salinity and temperature in its inner estuaries.and has very little zonation from Maine to southern Texas. In outside sea waters., however, temperatures and salinities are fax more constant and there are characteristic biogeographical zones* Around each cape there are species substitutions as at Cape Cod., Cape Hatteras., Cape Canaveral., etc.0 whereas in the inner estuaries the substitutions are fewer. As one moves south on the east coast.. temperature and tidal stresses do,decrease although salinity variations often increase in the sub- tropics because of erratic rainfall. The interplay of the fluctuation type of energy stress seems to predict whether generalized stress -systems pre- vail or whether characteristic latitudinal types result. The flows of estuarine energy on eaxth may be considered conveniently in three latitudinal groupings., tropical, temperate and arctic, Tropical systems have higher drains of thermal dissociation requiring more respira- tory work maintenancej, but programs of temperaturechange are often less variable. Light energy is greater on the yearly average and more regulare Tidal and wave energies are usually less., although exceptional energies develop in infrequent hurricanes. Arctic systems have extreme shifts in light and dark programs of solar insoliation.. variable temperature and the 40 waikele Pftlt. Kaneohe OAHU Fishpond Pearl Harbor UPPER LOCH W ES T onokulu (DWalker's Bay Bed (3)Honouliuli Parallel Bad @Loch Pt. @Loulaunui Bed 00ne Rock Bed lounuf Island @Three Rock (DYoshida Bed @Matsuyarna Bed (9)Hooece-Walkele Bed LOWER WEST LOC H Y analog Pt. Walker's Say Intrepid Pt. Nichol's Pt. I Location of eight oyster beds sampled for condition in West Loch, Pearl Harbor, Oahu, Hawaii. Names of oyster beds after Sparks, 1963. Fj 11. 0 Zirginica) yster reefs (Crassostrea .. ina disturbed 1@opical environment (Sak-uda,- _1900 0-J. 50 JANUARY 50 JULY N. 40 N- 20 011 0 5 FEBRUARY 5 AUGUST N.71 N=30 OL 0oul In to W W _j ;e 50 MARCH M50 SEPTEMBER N.52 N=66 OL 0 11L j z 050 APRIL 050 OCTOBER I I U. W 001 IL N.30 0 0L1h:1 N.40 W W 0 MAY 15o NOVEMBER 450 z N.40L z N.41 W 0 OL Q. 50 JUNE 50 DECEMBER N.20 Nz 30 0 2 3 4 5 GONAD STAGE @ONAD STAGE L -Monthly gonad stages of oyster (C. virginica) in West Loch, Pearl Harbor, Hawaii. Fig. 12. Storage pattern in a tropical regime. 41 10. 10- 0 5. 5. X X w 2,@@aiker's Bay Bed N=44 W One Rock Bed N- 51 2 Z V z 0 . . . . . . . . . . . . 10. 10. z z 0 0 0 z 5 z 5 0 0 U U 2 Three Rock Bed N-44 2. Matsuyama, Bed Nz44 10 (o14.4) 10 5. 5. X X W W 0 2@ Honouliuli Parallel Bed N. 45 0 2. Laulaunui Bed N-- 44 z z 10. 10. z z 0 0 z z 105 0 5 Q . U 0 Yoshida Bed N=44 HooeQe-Waikele Bea. N.44 2 0 J F M A i 6 A 6 J F M A MONTH MON+H Average monthly condition indexes of American oysters from eight beds in West Loch, Pearl Harbor, Hawaii. Circles represent C. L values presented by Sparks (1963) for samples from the same beds (North Gate Bed of Sparks compared to Matsuyama Bed from this study). Fig. 13. Oyster characteristics in 9 tropical regime .(Crassostrea virginica (Sakuda, t966b). 0\ 0 21 0 42 action of ice. The temperate systems are chax-acterized by moderate light pulse with season., moderate temperature ranges, moderate temperature, large tides and large waves. Power and Communication Connectives It is a property of most estuarine systems that they are coupled to other nearby systems of freshwater or open sea by means of flows from one to the other which have controlling effects. Examples are the migration of populations of fishes with reproduction one place,, nursery growth in a second place and., sometimes,. further action as adults in yet another place. These populations are participating as components in more than one system aniby the timing of their participation they serve to even out energy loads or place controlling energy drains which accentuate fluctuations. If by such timing of their life cycles these populations arrange for special inputs to their own processes,, they are assured a continuing role. Insuring continued support from the system., the migrant provides some control service in exchange for its effect of feeding. The migrations of salmon,, shrimp and other organisms are examples of inter-power system 'Connectives., in the same sense that telephone and power lines connect cities. The roles of these flows in one system are that of an outside energy flow., although sensible management requires that consideration of the cormective as a whole mechanism be also considered. Power transmission systems are a property of systems with regular programs of production and stress. They permit more diversity and efficiency in-a locality than could be supported through seasons of the year of minimum energy and maximum stress. The phenomenon of migrating major pulses increases generally with latitude associated with light and temperature cycles although there are major pulses in tropical zones wherever such patterns as monsoons and shifting doldrum belts change rainfall and salinity regimes. Much emphasis has been placed in a century of work on fishes like salmon,that reproduce in freshwaters and move into the sea during their weight gains,,and components like the Anguilla eels or Penaeid shrimp that reproduce at sea and move landward dii ing weight gain. An exami ion of all these moving populations suggests that the critical aspect of survival is synchronizing the populationsmain energy need in phase with a strong pulse of energy availability. Whether it is king crab in Cook Inlet, Alaska (Bright, Durban, Knudsen, 1960), shrimp of the bays of Texas (Odum, 1967bN, or salmon passing through lakes and estuaries during their period of most rapid veight gain (see Chapter F), the patterns seem similar. In earlier studies security of the reproduction process has been emphasized. In the last century., marine fish hatcheries were developed. They failed because no one had any idea of the numbers involved in these 'processes and drop-in-the-bucket levels were involved in the hatcheries. The public still retains this kind of view. Predictions of salmon and many other stocks an- still being developed on the assumption that the limit ,ing factor in stocks is the number of young launched. Where a river is blocked to salmon ora bay blocked to sbrimp.. reproduction does limit., but what about the usual pattern? For salmon', and many other heavily studied species 43 data do not exist fully to prove the theory of population as the limit at ma imum energy de-and stage (per population). Theories in -vogue in'management agencies permitted management of s]*c.ies to be done independently of management of the whole system. Not only are there migrations from the sharply pulsing estuary to the lesser pulsing open sea systems,, but there is a general latitudinal migration of large oceanic, and coastal fishes north during the productive season and back South during the low productive season, thus helping to spread the seasonal energy pulse more evenly over the oceans and coasts. The five main divisions of our classification are-given in Fig. 149 Latitudinal differences exist in the highly stressed systems of natural and man-disturbed types., but these are considered as variants rather than as entirely different systems. Where salinity., pollutioal,and wave stresses are not great, latitudinal differentiation occurs with quite distinctively different systems recognizable with latitude related to temperature levels., to seasonal programming., and to migrating populations. Plankton and Bottom Differentiation Even in the freshwaters., one readily classifies systems according to, the role of the bottom subsSrstems. For exampley many recipes for fish pond management concern the competition between plankton systems and benthic plant dominated systems,, the one shading out the other or taking away nutrients because of its ability to hold a motion relative to the moving water. In the coastal systems we may distinguish four main classes of sys- tems related to depth and the,role of the bottom. Seaward of the coastal systems if one is at the continental slope the bottom of the seas may drop sharply away so that the surface ecological system has no bottom. The phenomenon of the deep scattering layer develops and one has the surface system coupled to a complex migration of shrimps and other animals moving up_-and down each day.and night. In general any system with '@L deep scattering layer subsystem under it is outside, of the scope of our effort to classify the coastal systems except vnere it is continually washing up on shore (Chapters B-5, C-12). For purposes of classification we separate those. systems with sufficient clarity and shallow water so that the bottom attached plants have 50% or more of the plant photosynthesis. Many of the salt ponds of New England have important.bottom communities as do the bays of Texas* Shallow productive systems bathed with tidal waters and little salinity fluctuation have high productivities and moderately high diversities. Among these systems and subsystems are the eelgrass beds of the temperate latitudes and the turtle grass meadows of the tropics. When the bottom is too shaded for major plant production the photo- synthesis is by the pbytoplankton and the food chains are based on zooplankton and zooplankton-feeding: fishes as well as on benthic filter feeders., the clams., mussels and oyster reef subsystems. When the water is so deep that the bottom becomes unimportant., the main consumer system is that of the plankton food chains as tbrough herring-like fishes, Most estuaries have fairly equal roles of benthic and swimming consumer components because of 0 E E Z ARCTIC SYSTEMS E 00 W CL (D) > 01 0 C:4 0 .2 C C 0 r NATURALLY DISTURBED STRESSED SYSTEMS 0 '0 01 01-1 W Ol TEMPERATE SYSTEMS SYSTEMS' (E) . La 1.. "0 1 J '01 0 (C) -V 1. wide Mi 0 latitude Ei range 01 C (A) 0 TROPICAL-,S@STEMS (B) CD S loor", Increasing. stress energies Fig.. 149 Relationship ..of -the main categories of ecosystem classification to latitudinal factors and-other stresse@ 45 the intermediate depth of the bottom. The benthic consumers are a subsys.tem that varies in its importance, being a minor component in deep estuaries and a major system of energy processing on clam flats. West Coast and East Coast Comparisons It became apparent soon after the state surveys were begun that the systems of the east and west coast could be placed. under the same categories even though there were different names of species dominating in many instances. We confirm, therefore, the "parellelism"' generalizations of Thorsen (1957, 1958). On both coasts salinity changes are a main st ress. Temperature fluctuation on the east coast is due to sharp shifts in strongly flowing air masses, whereas on the west coast the stress comes from upwelling and injections of cold water from the sea. In general the stress severity of the east coast was,greater so that west coast estuaries often had several species occupying the role of a single species on the east.coast. In Table 2 are some equivalents suggested among dominant and commercially important species of fish and crustacea from the east and west coasts which seem to occupy similar roles in similar systems. Figures 15 and 16 diagram the manner by which energy drains of stress, such as sharply fluctuating temperature, salinity and'pollution wastes, channel energy into fewer species. When conditions are less stressed, energies of the food chains go into specialization and division of labor providing more zones,each occupied by a different species. Thus the less stressed estuaries ' of the north- west coast have more benthic clam types over the zones from fresh to salt water than at an equivalent latitude on the New England coast. More energy is avail- able for the differentiation and organization that is necessary to prevent com- petitive exclusion. Introduction of Faunas The introduction of faunas has been controversial in ecology. However, the experience of establishing the Japanese oyster in estuaries of the Pacific Northwest or exotic and fast-growing,trees suggests that opportunities for developing improved yields to man may come fr6mbringingin species less under local-controls. On the other hand the fast spread of agricultural diseases, weeds and animal pests in American cities suggests,dangers, cautions and difficulties of'predicting outcome of transplants. According to Elton (19,58) and many others, the fast spread of transplants in spectacular and permanently disrupting ways on big continents is associated mainly with areas already dis- turbed there. The transplants do not invade the well-established large systems, but enter the disturbed areas or the small or remote a 'reas that,may be regarded as missing major elements of possible support. In marine waters, ships and currents enable frequent introductions. With the development of more distvrbed estuaries, more successful invaders may be expected as part of new designs for new conditions. For those considering transplants or the dangers of introductions, the classification of estuaries may be useful in helping to indicate areas where analogs are to be found which may have adaptations to similar regimes. Table 2. Examples of West and East Coast Niche Substitutions, Gulf'Coast@Equivalents-and tropicaltypes when stressed. System Type Description of Role Tropical Up.per Gulf Coast Upper StressetA West ICoast East Coast Oligohaline river Clam with great capacity Mya arenaria Rangia Mya arenaria mouth to burrow from cold and adapt to salinity variation Oyster reef niche Crassostrea Ostrea gigas Crassostrea Crassostrea virginica virginica virginica Middle salinity General crab carnivore, Callinectes Dungeness crab Blue Crab Green crab, estuary moving in and out of Cancer Callinectes Cancer varying salinity High salinity Top carnivore in bottom Panullrus King crab Stone crab Homarus estuary irregularities iobster Paralithodes Menippe lobster Kelp system Algal forests, bottom Macrocystis- Laminaria attached seaward of surf Beach and surf Deep digging clam adapted Spisula Razor clam Spisula Spisula surf zone to heavy energies just Siliqua clam seaward of breakers Surf zone sand dollar Mellita Dendraster Mellita Echinarachnius Intertidal Grazers of intertidal Littorina Littorina planaxis Littorina Littorina rocks* rocks, periwinkles ziczac Littorina scutellata irrorata litorea Intertidally protected Balanus Gooseneck Balanus Balanus filter feeders @@phitrite barnacle eburneus balanoides barnacles, Ulva Ulva Ulva Ulva Ulva Coastal Plankton Zooplankton eater Anchovy Pacific herring, Menhaden Atlantic herring Sardines Threadfin Alewives *Hedgepeth (1953o, 1967) 47 Rosa rio Sirad "A 01 liacoma-Paphi iome and Ba /anus -Littor' me Neph1hys faciation 31L Heteromastus Faciation Typical Cucumaria-Scalibrelma Association Piperata Faciation thres of tkis 104-nd I@Jic t iJa (ion -Dita 4 shelf_@) Am mo c hares -fudgment Faciation [cotone between Cucamafia-Scalikom 2 Ass@.& Strolkentm@s-Ar@oNccinum siom 65 is Y2 Km ouLh Provisional map indicating the faciations of the Cucumaria-Scalibregina asso- ciation (Pandora-Yoldia. biome) in and adjacent to East Scund. Either a narruw strip uf 'Macorna-Paphia bionie, or the Pisaster ochraceus faciation of the Strougylocentrotus biome occurs between the Cucurn aria- Scal ibregma association (or its faciations) and mean low tide. The ividth of both of these is greatly exaggerated. The intertidal area is occupied locally by the Nfacoma-Papbia biome in its lo-wer edge and by the Balanus- Littorina biotne elsewhere. These details cannot be shown, to scale, on this map. Fig. 15 . A north temperate estuary with relatively uniform salinity and temperature regimes allowing energies for differentiation of bottom subsystems. East Sound in Oreas Island, Puget Sound, Washington (Shelford et al., t935). 70155' 48 Carr k?% is. rRar Atlantic Salisbur Ocean Intertidcl area R N. JWY 0-6 feet 7-- -12 feet 6 Plum 12-18 feet sielty LM 18@24 feet Island wer *24 feet Wood Scale 1:20,000 bridge IS. 0 500 Moyards Newburyport Newbury Salisbury Plu Is Ion Point Newburyport Old Woodbrid Point Marsh Islan edl L 10011' Newbury Moderately Contaminated Areas: 94.9 acres .(Open to digging with treatment) Grossly Contaminated Areas: 435.3 acres (Closed to all digginj for human consumption) Fig. 16 . Merrimac Estuary, Mass., stressed by large temperature and salinity variations. The enlargement below shows soft shell clam beds which predominate ,(Jerome, Chesmore, Anderson, and Grice.1965) 49 Species Thay be rapidly reprogrammed 61iy�iologically, genetically, or by substiiuiidn of stocks) to time their e"neirgy demands and services to the sys- tem so as tb.maximize its own S'utviv@l and its contribution to the system pattern's survival. Sakuda (1964)1i.Ns. 12 and 13 shows for the oyster, 9 Crassosttea virginica, different patteins of body thickness and reproductive ke temperate latitudes. activity in Hawaii as compared wit@ mo The Historical Factor Deep divisions of opinion and belief exist among biologists considering the distribution of marine organisms and their ecosystems. Many biologists are concerned with long term evolution,.@peciation, and other historical events that have made available the present genetic material for ecosystems. Some believe that organisms live at a place if they can get there and if there is nothing toxic,or lethal to them there. Being concerned with-evolutionary pedi- grees, these biologist's consider one taxonomic group at a time and draw maps of distributions.fr'6in which theories are derived regarding possible events which increased access, mechanisms isolating stocks long enough for genetic change, and oiher historical actions. These theories do not require of the organisms tbai,th,6y contribute closed loop work services, mineral cycling, economy of adaptations or'.other ecological performance criteria as a requirement for incorporation into a system. These approaches sometimes contrast with, ecosysiem theorists, starting with Darwin, who found the requirements of the system imposing choices on whatever genetic material was at hand to develop adaptations r'equired,for system survival. Surely both are necessary for the existence of an ecosystem: (4) the genetic information represented by the species, from which ch6ic-es'.may be made and (b) the selective actions of organized system in loop rewarding those species which make service contributions that optimize the systeml,s energy utilization and mineral cycles in work towards survival and continuatidn. With the strong energies of circulation in the sea, the historical factbr may not be critical in limiting a system in any one place. The argument overthe importance of historical access is involved in all plans for change as with the proposed Panama sea level canal. Biogeographic Classifications Examotes of the' biogeographic province approach are given in Figs. 17 and A figut'p i7 ate zones of similar temperature regimes to which many species are correlated because of their physiological Adaptations for maintenance, enzyme opeiaiion, seasonal programming of reproduction , and common access to genetic po6l@. The ultimate reason for the'co'rrespondence of seasonal program- ming @[email protected] regimes may be that both are a function of the energy input program from the sun and other sources. The seasonal energy pulse moves through the compartments of the food chain as heat'energy accumulates in the water. Similar light energy regimes tend to develop with similar temperature regimes. In Fig.18A are calculations of similarity with latitudinal zones on the west coast by North and Hubbs (1968). Biogeographic provinces are also shown as classified by those'studying animal distribution on the west coast without regard to the systems the animals are serving. . -Although discontinuous patterns in faunal lists are found when sharp changes in temperature occur on some capes such 50 ISO- ISO- ARcnc COLD PQ --- - --- - --- AUUTIAN COOL TEMPERATE - --iEMPERATE OR=NLAN 3i I CD NNDAIAV WARM TEMPERATE ------- HOSHLALN W-05 TI F-i . .- T -.- A CALIFORMAN INNER TROPICAL --MAGOALENAN AMIC Pacific molluscan prov inces and subprovinces; the northern boundaries mark the northern lati- tudinal limits of a significant number of species. 1farine climates, based on the duration of marine tempera- tures at the limits of molluscan species. Base map from U. S. Navy's Marine Cli!natic Atlas of the World. too- so- go- 40. 20. 0 L I . d - (............ ARCTIC ^40 NORWEGIAN 0 L D/ @O' 1z 19, ARcnC OV 0. CELTIC VSA' LUsrrAN C MERRANEA -40. VUtGINL4N OUTER TROPICAL T. iclkl uterfr@pica 01 - CAROLINIAN -1 MOROCCAN ARMBEAN INNER TROPICAL !N4 44*k - \\ 2 0. Co. so- so- 400 20. 0. 200 40. Atlantic molluscan provinces. and subprovince;' the northem boundaries -mark the northem latitudinal limits of a significant number of species. Marine climates,'based on the duration of marine tem- Peraiures at the limits of molluscan species. Base map from U. S. Navy's Marine Clintatic Atlas of the World, Fig. 17. Biogeographic provinces related to temperature regimes and faunal similarities (Hall, 1964). 51 OCEANIC ZONAL SPECIES SHARED WITH NORTHERN TEMPERATE 70NE ZONE SLI&DIVISION 20 30 40 50 ALASKAN JUNEAU BRITISH COLUMBIAN BOREAL CAPE FLATTERY PACIFIC OCEAN OREGONIAN -27% CAPE MENDOCINO C ENTRAL CALIFORNIAN @1@111 wfl@ 291% PIOINI CONCE.PTION 14611ITI41ERN Son Diego A P NTA BANDA C N E TEMPERATE PUNTA EUGENIA SOUTHERN CABO SAN LUCAS Decline in affinity with-the4an Diego fauna as a function of distances. Boreal and tem@wrate z6nei after Hedgpeth. (195Yj, with Point Conception taken as the boundary. The zonal suAdivisions are mainly for clitscussion.,0urposes and Imay or may net be of 2oogeo- graphic importance. Fig. 18A4 . Biogeographic province's on the U.S. west coast with affinity calculations (North and Hubbs, 1968). '80 .20 .00 1" '140 NTER IC7t WINTER 56. Is 3 1- 3 oft -so -Four zonal types of distribution I Extent of the four major zonal types based on the mean temperatures at Newfoundland and Cape Hatteras as limiting intensities (from Hutchins, 1947). Fig. 18B. World temperaiure regimes (from Hedgepeth, 1957). 52 as Cape Cod or Cape Hatteras, the ecosystems may be continous with little change in general character because of niche substitutions. The boundaries of biogeographic provinces thus do not correspond with boundaries for ecosystem types and thus may not provide a basis for management. Species adapted to the more severely stressed conditions tend to be world wide.and less related to biogeographic provinces. Heald (1968) in proViding approximate maps for fisheries (shellfish included) finds patches and zones -rather than continuous distributions corresponding to biogeographic provinces. Ecological differentiation determines the systems' rather than the factors of access and temperature. Arctic Systems As one moves north, and the pulse of temperature and photosynthesis gets more and more extreme, the properties of temperate zones of the main coasts of the United States retain much of their character with some variations and species substitutions. Entirely different systems appear with the presence of ice as glaciers, as glacial melt patterns, as sea ice stress and in systems that are actuall@ ip and on the ice. The combination of extreme tides and extreme cold increases'ifitertidal stress on mud flats beyond.that capable of supporting temperate types of systems. In our classificationwe identify as Arctic only those systems-fiot recognizable in the temperate latitudes. .Tropical Systems Although stressed systensare similar in temperate and tropical versions, systems not exposed to sharp stress are characteristically different from those of temperate latitudes, with species that have neither low temperature adappations or adaptations for sharp seasonal changes. Thus the coral reefs'4tropical-plankton waters and oceanic mangroves (in areas of small tidal range) have long been re- cognized as types of maximum diversity and beauty, of maximum aesthetic value. A system is characterized as tropical when it is associated with*stable conditions, generates high diversity and does not occur in areas subjected to frost. Diversity of Contributing Subsystems in Large Waters When salinities and temperatures have only moderate ranges, when other energy stress drains are small, and when the system size is large, the division of specialization is not only by inclusion of many species, but @ub-system's of relatively 'low diversity are developed that provide a pattern'of alternating diversity much in the way that a country-side is dispers@d with cities of different main contribution to the overall economy. It is important to an understanding of the estuarine systems to define both the subsystems'and the overall system as well. Thus the bottoms of high salinity stable bays kre divided up into sub- systems of benthic clams and worms, each being dominated by some associations while the overall bay system in toto has a large diveisity of @pecialists contri- buting to the pools of minera_lr@u_trients and plankton.9perat6ri. Examples are the patterns of bottom associations on the continental shelves as reported in extensive studies by Zenkevich (1963). The patterns of alternating subsystems in benthic. fauna is found in estuarine regions in the higher salinity bays and archipelagos as'With the_exampl@ 6f 53 14ercqaaria clam beds off Massachusetts in Fig. 19 (Ropes and Martin, 1960). The specialization of beds of different species, which all contribute to the single system of water, mineral cycling and plankton drifting by, is another example of the division of niches possible when stress is less and there is high diversity of large animals, distance-, temporal programming, channeled mineral flows and other organizational mechanisms preventing competitive ex- clusions that might otherwise develop. ECOLOGICAL SYSTEM TYPES IN THE CLASSIFICATION The proposed classification of coastal systems is given in Table 1. it was derived from considerations of energy inflow, stress and diversity develop- ment plus a lot of intuition and suggestions of-bur many discussants. The names.used for each,system are not really important, except that we have sought common words in their regular English usage, selected to-suggest the features of characteristic energy flows responsible for our recognition of.the type. For clarification, column 2 of Table 1 lists the energy source or energy stress which is characteristic. Following Table 1 is a consideration of the basis for the recognition of each type. Indicator Species in Stressed Systems In highly diversified systems such as the near-shore shelf waters no one species is a system indicator because with slightly different conditions, a different species is tuned to take over local dominance. In the stressed en- viroments and those requiring much programmatic adaptation species are few and those present are so highly adaptive that their presence identifies.the nature of the regime. Bottom animals have proven useful as indicators of systems as shown by Parker (1959) in Pip,. 20. The extensive efforts to use foraminifera for this purpose is the iubjecr or Part II. Jeftries (1962b)using Raritan Bay, New Jersey summarizes use of 8 calanoid copepods as marker of steady iniection of coastal plankton into systems characterized by mixing. Salinity Adaptations Salinity adaptations apparently require considerable energies, not so much in the actual operation but in the carrying of'the physiological machinery and programs of response to salinity fluctuations. In Figs. 21-2Sare some salinity ranges for which certain species are adapted. Under these conditions they substitute in the niches for similar species which.are adapted for otherranges. The adaptations are not only to the salinity level but to the range of fluctuation. Sloan found very high diversities in regular estuarine salinity ranges where the water was steady because of its source in salty springs, as contrasted with low diversities in tidal estuaries where salinities.are continually fluctuating daily'and seasonally- The fairly low diversities in the estuarine waters at the mouth of Lake Maricaibo: Venezuela (Fig.ZZ ) contrast with the higb diversiti.es in waters ai the some latitude not exposed to continual saiinity 'shocks. Sanders, Mangelsdorf and Hampton (1965) showed in the Pocasset River estuary that the infauna in Wre stable salinity was diverse, while the fauna more exposed to the shifting salinities in the waters above were few in species (Fig. 25). These examples and others cited in the chapters that follow emphasize the importance of the fluctuation of properties in diverting energies from other potentials. 54 NARWICH PORr IEGE.D lie C? 00 '@AWA m/5'" 0, .01 so7 11 1111N11 1; r 00 r A 3w CAPE Poer, EVVA '0 GfiTA r POINT 2d] CD Fig. 19 Hard shell clam (Mercenaria mercenaria) abundance (bushels per 1-hour tow) in Nantucket Sound, MassWc-husetts (From Ropes and Martin ig6o; Fig 5). 55 Ral?gia CrOSSOSIrea Nuculona Aequlpe@fen 1 2 3 4 Small Riw@ H U: M I. D RIVER I/Irt UENCED LOW SALINtry ESMARY rER H U M I-D,- S U B_* E@ r""2 "0"' BAY S E M Low ro MFOICIM ..FRESM SALINlry A R I D .:@4 iR'ACK*1SH' @TER 3 HIGH SALINlry SA@T M BAY CENrERS ...... ...... SHALLOW GRAS@@Y 457SALr LAGOON VARIABLE BAYS 4 @MAASNES s4zINlry sm,&Ds HIGH sALINtry BAY MARGINS 6 7 N INLEr Yker ImEr 5 5 6 7 8 meffita cerl/h/um Nerifina Ana-nalocardla @fe @V Z,,a,gr --a,,c repr@sentation of bay and lagootial macrO-invertebrate environments y' in reLation to g provinces. Figured species is not everyvhere found in the Texas region, but represents genus found in these environments throughout North Arnerica. Rangia (1) also found at Delta shores and distributaries of large rivers. Nucidana (3) also common in variable salinity sounds and pro-delta slopes. Jfdlita (5) migrates.through inlets into bays. Certain species of Neritina (7) also found in fresh- or brackish-water marshes near large river mouths. Fig.'20. Indicator bottom animals in ecosystem types of the Gulf of @,Iexico (Parker, 1959). 1 and ?, oligohaline system; 2, oyster reef; 3, medium salinity plankton system; 4 and 6, shallow bottom vegetation system; 7, salt marsh; 8, hypersaline lagoon. SALINITY TOLERANCES OF SOMEINVERTEBRATES OCCURRING WITHIN THE 56 DELAWARE RIVER ESTUARY (compiled from several sources) RANGE OF SALINITY TOLERANCE ORGANISMS 0 5 10 15 20 25 30 35 40 (1) Cliona celata _TFo_ri7n_gsponge) ...... ...... (2) Nereis' succinea L __Ta_c1_amw`or_m_F (1) Crassostrea virginica JAtlantic oyster) .. .. .. ... ... ..... (3) Urosal inx cinerea P .. ....p (oyster dri (1) Callinectes a dus (blue crab (4) Neo@anc?.pe texana sayi tbay's mud crab) .... .. (5) Panopeus herbsti (a mud crab) (4) Hexapanopeus angustifrons (a mud crab) (5 Eu4:yRanopeus depressus . .... (flat mud crab) (5) RhithroRanopeus harrisi (brackish water mu crab) ... ... (2) Aeginella lon i ornis liong-Rorned caprellia) (1,6) Loligo pealii .... . .. .... .... .... n (common squid) (1) Lollijzuncula brevis (shoFt squ ... . Sources: (1) Spector, 1956; (2) Amos, 1954 and unpublished data- (3) Carriker, 1955; (4) Cowles, 1930; (5) Ryan, 1956, and Haefner, 1959. Stauber (1943) pointed out, in discussing a graphic method of representing salinity condition in Delaware Bay, that species are limited to certain regions of the estuary by the effects of the extremes in the salinity range and of their duration rather than.by the average conditions. For a further discus- sion of tolerances see Fry (1947). At summer temperatures (20-27*C). Can withstand short-time salinity changes of 0-42 O/oo in the laboratory (1). Can survive salinities as low as 8 O/oo during the winter (2). Fig. 21. Salinity adaptations of estuarine animals in a temperate area (Shuster, 1959). TIE SFOXGILLA.ASPINOSA 54N CARL05" 11- 00, 7 BALANUS IMPROVISUS BALANUS AMPHITRITE'NIVEUS LIGIA BAUDINIANA C) 000000 CALLINECTES SAPIDUS % r04 5 CALLINECTES ORNATUS low a dommoom mdomme, CALLINECTES BOCIDURTI j 4 oweesm owls PANOPEUS OCCIDENrALIS 1 1 1 1 PANOPEUS RUGOSUS @Wwov RHITHROPANOPEUS HARRISII jwIO* METASESARMA RUBRIPES SESARMA MIERSII Iddo TA8LAZ ARATUS PISONI BAY UCIDES CORDATUS OCYPIDDE @UADRATA UCA.MARACOANI . . ......... . ... )m, Inds 46 m qo GO do 40 GO 41111,41 ad LJCA RAPAX To. UCA MURIFICENTA v, PALMAS UCA CUMULANTA Oman monow dwan 4*04 UCA.LEPT01)ACTYLA U@MAAPUS COFFEUS moom am=WdwmmO@ NERITINA RECLIVATA NERITINA RELEAGRIS LITTORINA'NEBULOSA CAFYTAN CHCO T POTAMOPYRGUS SP. .4 THAIS HAEMASTOMA FLORIDANA wo Mo an IDEPTH COWOURS Z POLYYESODA ARCTATA 6 M, MYTELLA FALCATA B. M. MARACAIB CPASSOSTREA VIRGINICA Map of the northern portion of Lake Maracaibo 0 10 20 30 SALINITY Fig. 22. Salinity adaptations of estuarine animals Salinity ranges of the invertebrates found in the estuary. in a tropical estuary, Lake Maracaibo, Venezuela (Rodriguez, 1963). 58 n-45! n--' mff cIrt. .7 Ora, P*# ;6 .5 .9 a. P" .4 o" 90 O.LL.wr .Q..r 3- MOREHEAD CITY SEA FORT 2 L Ar4ANr1C OCEAN Chart of tljc 11caufort (N. C.) area shO%%ilig location of bydrograpliie stations: I-Sbark Shoal, Pivers L, 3-Gallant Poiiit, 4--Nvi%*Port Marsb, 5-- b Point, 6-Midway, 7-White Rock, 8-Turtle Rock, Cross Rock. Conditions and results of salinity tolerance experiwents. Length Numbcr Temperature My sar ij Species mage 'i., (mm) int 111 (0/00) AUG.2 O.__ ssarius ribez ............ 11-17 13 22.8-20.2 9 Thaitfloridana ............ 47-78 4 28.0-28.6 9 J 30. No Gastropods: 20 -] Odostmia i.pre= ......... 1-4 28.0-30.0 11 X, AUG. 13 Vmsalpinx ci.erea ......... 12-30 20 26.1-28.1 11 20- Bm.ywn carica ............. 41-86 4 26.0-26.3 11 0 AUG.27 % Cerithium floridanum.. ..... 2448 6 26.0-26.5 13 X, % FasciDlarta hunleria .......... 38-91 3 27.5-28.5 17 x b CardAa@rus findus ........... 15-30 16 26.5-27.0 is SEPT. II Thais veligffs ............. -7 50 25.0-27.5 9 so 'x Ceritkum Yeligers ..........- 3D-70 23.5-26.0 21 Pelecyp@ds: x Macenaria merornaria ...... 30-123 4 25.3-27.3 (0) 0 Atodiolus demisaus ......... 62-08 6 28.2-28.9 5 Craseostrw rirginica ........ 20-117 6 26.0-28.0 7 ox;-@9 Brach idonw uudw ........ 8-22 25 24.5-27.5 13 STATION 1 2 3 4 3 4 7 a Chionecance:1104 ......... 1840 11 27.0-29.5 19 �alinity proffles, August 2, 13, 27, and D@capocls. - September 11, '.\ewpurt River, 1955. (Hurricane Connie Paw;vus Acrbsti: .......... 20-40 4 24.D-27.5 3 passe4l on August 12, and Diane, on August 17.) Eurypanopfus depressus ..... 4-17 11 25.0-27 .5 3 Clihonariu8 riftl ..........- 2 26.0-26..S 3 Pagurus Jongicarpus .... -' - Is 22.8-26.2 9 Echinoderms: A,f,wfo,bcsi ............ 5&120 4- 23.5-26.0 17 Arbacia pundul4ja ......... 47 2 27.5-29.7 iq LuIcthinus rariegalus ....... 48 '1 2 23 16 specimcus in 14, 16, and 18 o/oc, dilutions. Fig. 23A Silinity tolerances in the field and laboratory at Beaufort, North Carolina (Wells 1961). GRAV INA 2 59 PORT FMALGO 26 2 19 25 W _j 0 17 Is RED HEAD .91 15 16 00.0 600 4 14 oil MAGNETIC NORTH eRAVINA PT SHEEP P 141020 146* -Location and U.S. Fish and Wildlife. Service reference number of spawning streams in Port Gravina, Prince William Sound. ECHIUROIDEA TIDEFLAT MIDDLE SLOUGH MAIN STREAM ECHIURUS ECHIURUS ALASKENSIS ANNELIDA OLIGOCHAETA (MICROORILE) ARENICOLA PVSILLA NEPHYTES CAECA NEREIS SP CHEILONEREIS SP ARTHROPOOA DETONELLA PAPILLICORNIS NEOSPHAEROMA OREGONENSIS IDOTHEA WOSNESENSKI GAMMARIDAE HEMIGRAPSUS OREGONENSIS PAGURUS SP BALANUS SP. CHELONETHIDA EPHEMEROPTERA- IRON SP PLECOPTERA - CHLOROPERLIDAE MOLLUSCA MYTILUS EDULIS MACOMA NASUTA MACOMA BALTHICA CLINOCARDIUM NUTTALLI PROTOTHACA LACINIATA SAXIDOMUS; GIGANTEUS MYA TRUNCATA ACMAEA SP LrTTORINA SP ECHINODERMATA ASTERIAS SP VERTEBRATA ANOPLARCHUS PURPURESCENS PHOLIS LAETUS 1119 7 5 3 1 0 11 9 7 5 3 1 0 11 9 7 5 3 1 0 TIDE LEVEL (FEET) n '/ICNOR of organisms by tide level, Olsen Creek drainage, 1961. Fig. 23B- Adaptations to tidal position and salinity range in Alaska (Halle, Williamson, and Barcly, 1964). STATION NUMBERS 3 5 6 U a; STATION NUMBERS GULF OF XILXICO LOP I z Ub z GULF OF MEXICO W 0 3 'WI dr Jr W-5 rLf DISTANCE IN MILES FROM SPRINGHEAD 0 2 0 '0 -valuCS in Homosassa Springs. DISIANCE IN MILES FROM SIPPINGHEAD Chloride W-4- GlAoride values @.ri VVeek!%N-achee Springs. I H.5- W-3 STATION NuMSERS 4 STATiON NUMBERS 2 60- I MILE 30 W-2 5 40[ W-1 SPRINGHEAD GPRINGHEAD HOMOSASSA SPR:IqGs a '#E-rKIWACHEE SPPINGS to DISTANCE IN MILES FROM SPRINGHEAD 14 0 2 4 6 12 -en ironi collect- DIS7A ICE IN M FROM SPR!.1JCHEJ1D Numbers ot insect species ta' Nwnbe:s -oi rscct srecic' taken from collect- ing stations in 14oniosassa Springs. St_ 'ItiC,115 @n [email protected]';%_ &Ce in, Springi. W.3 0\ Fig. 24. High species diveksities in oligonaline salinities when they are steady as in Homosassa Spring, Florida (Sloan, 1956). Also shown in a freshwater spring in similar situation a few miles away. Faunas of both are mixed marine and freshwater origin. aq @4. ra 0 0 01 ca N 0 ra 0 m 2.25 KM \0M ON VEPM, CM '76 t-d 0 C+ z;; W ETEONE METEROPODA (1) CA C+ la. I STREGLOSPIO BENEDICTI (1) CD m @L OLIGOCHAETE B. (1) Ell t! G" C+ 1-3 ;:N S. N) C+ Ss LEMON AMERICANS (1) (D Inm 0 =g t:r c+ 0';1GQ ANAPERUS GARDINERI (1) 110, rj :Z, 0 NEREIS SUCCINEA (2) HYDROBIA SP 13) b. OD GEMMA GEMMA (5) 0 0 CL 7 '00 Q.," ol -4 -3.0 rl) C+ M EDOTEA TRILOBA (4) r" C+ oq co Er. R cn 2, ALMYRACUMA PROXIMOCULI go (4) 5..4 (D LEPTOMIRUS PLUMULOSUS 4b - L" c" - - -N - (4) .--- -- -\- T A A -4 OLIGOCHAETE A. (4) co Co v v v A 1:9 62 A. Naturally Stressed Systems of Wide Latitudinal Range First consider those types of systems which are mainly organized around high energy stresses and which have less adaptations with latitude as discussed in the theoretical section. By and large these types are more difficult to injure permanently because their structure is already adapted to energy stress and the high energies serve to disperse and process wastes. Rocky Sea Front (A-1) Rocky sea fronts occur on east and west coasts, Alaska, and Hawaii where glacial action, lava flows, or other geological action has left hard bare rocks at the shore receiving the pounding of open surf. In more northern latitudes rocky fronts are more important because of thescouring of glacial ice in earlier times and partly because of heavy wave energies that winnow away the deposit of beach sands. Because of the great range of tides in the north temperate zones, breaking waves cover a broader zone, and in northern climates summer heating stress is less on these rocks. For these reasons the characteristic distribution of algae and attached animals is better developed. With the sharp pulse of the season, surviving populations develop storage in animal and plant masses that last several years. The heavy brown algae carry on photosynthetic food making while exposed in air as well as in water. The mussels by their filter feeding of micro- scopic matter collect and mineralize plankton and detritus, releasing inorganic nutrients among the mats of algae. The algal production in turn is released back to the waters supporting plankton. Thus, the intertidal system is coupled to the estuarine waters, being a subsystem of the latter. Because of the recession of the tides, many kinds of marine grazers and carnivores are limited in access and large stocks of mussels and brown algae coat the rocks. Although bes t developed on the rocks of Maine or Southern Alaska the system of algae and attached filter feeding animals is also found on rocks where-they occur in jetties in Gulf States and on lava flows in heavy surf of Hawaii. In southern latitudes, the seasonal pulse and stress is less, tides are less and intertidal heating is greater. Animals have more rapid turnovers and are generally smaller and have less storage as related to seasonality. High Energy Beaches (A-2) South of Cape Cod on the east or Puget Sound on the west, sandy beaches become the most common coastal systemon the front shoreline which receives breaking waves. Sand grain sizes are self-organizing in dependance on the energy of the waves. Surging waters are received, filtered, and returned to the sea. Very characteristic burrowing Hipps crabs, Donax clams and interstitial cosmo- politan beach fauna participate in the massive sand filter in the processof filtering organic matter. The beach line provides organization to passing water masses and serves many reproductive cycles in which eggs are deposited at the beach. The characteristic long shore current supports many migrations. The sand may be quartz-dominated along the main continent, of dark volcanic minerals near lava flows, or calcareous where terrigenous supply is low and available hard matter is from coral reefs or other calcareous substrates that increase towards the tropics. High energy beach systems are similar at all latitudes (compare animals in beaches from different latitudes in Fig. 26 ), butthere are Wei@hqpper Emeelta ad beachawm crab unam Donax Polin M0 clam 'I, r CAMBARENE MADELEINES GENERAL COMPOSITION, OF A SANDY SHORES MSL@ ji LWS- 0kPPROX ::'.1 7, 41 -Diagrammatic comparison of zonation o W Ghana (Denu, Labadi) after, Gauld and Buch Madeleines) in Senegal after Sourie (1957). A, x ocy 4. a: 71 wifU; D, Glycera convoluta; E, Hippa cubensis; Z W -i j .0 > I W ckratulus; H, Donax rugosus; 1, Lumbrineris 0 Uroth6e grinald Fig. 26. Similarities in faunas of temperate beaches(A and B) and high energy beaches of tr A, California (Hedgepeth, 1967b 0 B, North Carolina (Pearse, Humm, and Whartonj 19,42). C. Venezuela (Rodriguez, 1959); D, Africa (Lawson. 1966). f .64 variations. At the northern boundaries'of the United States and southern Canada and Alaska, the winter stress on the beaches due to high wave energies and cold eliminate much of the biota, but just seaward in the surf zone and exposed at low tides are surf clams on both coasts. Of all the systems receiving pollutions of surface floating wastes, the beaches are most affected although the capacity of a high,energy beach for processing and mineralizing wastes is also large. Where wave energies are somewhat lesq additional species such as sand dollars become important and latitudinal differentiation appears. High Velocity Channels (A-3) Especially in northern waters of Maine, Washington and southern Alaska where large tidal waves are absorbed in archipelagos and inlets with deep channels, some characteristic ecological patterns develop on the current scoured bottoms and in the highly turbulent plankton waters. Even though the salinities are high and waters much like the open sea in character, the absorption of the energy of the world tidal wave into 10 to 20 knots tidal currents provides a special energy source and a stress. The same system also occurs in a few places in lower latitudes where there are inlets and converging waters as at Aransas Pass inlet in Texas. The scoured bottoms develop reef-like growths of encrusting animals and plants. Estuarine plankton associations, not characteristic of the open sea, develop in the moving waters. With food transported in abundance to any organisms that can hold on, *the density of attached life is*large although not diverse. The large eddies in the channel waters support microscopic phytoplankton of large individual size. The eddies and effects of the earth's rotation produce gyrals and other means by which floating and swimming animals and plants can slide back and forth with the waters. Adaptative behavior also permits populations to develop within the zone, with reproduction balancing losses. The great turbulence permits little opportunity for phenomena of stagnant waters to develop. Aeration rates are high because of the rapid removal and stirring downward of surface waters. The high current velocity channels are often b 'etween ecological systems of much greater diversity seaward and landward. The stress at the zone of contact may produce low diversity. Whereas zones of contact of resting ecological system types on land sometimes augment variety of components, the reverse is the pattern in these high velocity channels. Oscillating Temperature Channels (A-4) The widely oscillating temperature system is well represented by the Cape Cod Canal connecting coldwaters of the Gulf of Maine to the warmer coastal waters of southern New England. With large tides on the north, tidal currents in the sea level canal surge back and forth shifting the temperature twenty to forty degrees daily, and providing enormous stressto organisms that normally are delicately tuned to provide optimum metabolic processing for effective work at the temperature of their customary existence. Although such widely shifting temperatures are not common, they hold great interest in our interpretation of the workings of estuaries. The canal provides an advance look at the kinds of phenomena that may become much more common with the operation of nuclear power plants. Their output of large volumes of hot water may eddy and oscillate into the estuaries some- what in the manner of the Cape Cod Canal. Also, the channel has some similarities with7 the proposed sea level canal in Panama where cold upwelling waters of high tidal range in the bay of Panama to the south will be surging in a sea level canal and alternating with warm Caribbean waters of the type that support Coral reefs. As already mentioned in our preliminary cliscussion, stress reduces diversity, and in the Cape Cod 65 example there is a very low diversity system, including the stiess-resistant algae Ulva. and some tunicates and bryo7oa, mich less than that in the maxine waters at either end. Syste:,@@-%tists [email protected] irragined great invasions of faunas spreading throug1h such a ch.Panel, but this example suggests the mixing channel may be a barrier, elthough the stress of oscillating waters my develop stressed zones neax the m.-Gth in which faunas of the side with most stress may be most@compatible. Sedimentary Deltas (A-5) When great rivers carrying heavy sediment loads reach the sea they deposit sediment so fast that a special environmental condition is created with some features'of stress, and a characteristic ecosystem results. One special energy stress is the simple downhill fall of sediment. If the river has been in position for very long it may have filled its bay and built a fan of'sediment.out into the ocean as does the Mississippi, the Altamaha of Gecrgia, the Brazos of Texas, or the Yukon of.Ala,ska. AccompanyIng the river flow are varying discharges so that the delta waters are frequently stressed with sharp oscillations of high and low salinity as well as by the stress of blanketing silts. Although organic. matter usable as biological fuels are incoming in the river waters, substrates upon which to support filter type ani'mals may be quickly covered. Heavy turbidities shade out sun-light capable of supporting phytoplankton, at least until the plume of water slows down, drops some sediment, and becomes a lens of,low salinity water further out on the sea. The zone of heavy sedimentation is as much a property of the inflowing wateras of its own indigenous processes. Yuch organic matter gets covered over too fast for consumption, and mineralization is not efficient by the community or organisms with little diversity andppecialization. These systems are among those now receiving the most wastesy which if not readily absorbed or decomposed in the sedimentation ray remain in the, waters moving laRterally to stress other systems. As one moves away frora the zones of mximum stress other subsystems occur such as oligohaline water systems,oyster reefs, marshes, and clan beds. The nain delta deposition itself is dominated by geo- logical processes . colloidal actions on clay, and microbial action. Hypersaline Lagoons (A-6) Where sea water flows into shallow lagoons in climates with more evdporation than runoff, salinities.rise and briny conditions develop. High salinities require special adaptations by organisms in control of permeability and kidney actions. Diversities diminish and highly character- istic systems develop with a few species of phytoplankton, zooplankton, claws and fish in waters above 50 parts per thousand. Above 100 parts per thousand, there is mainly a system associated with Brine Shrimp. In gen- eral evaporite climates occur mainly in the sub-tropics in the U. S. repre- sented by south Florida keys and south Texas. Small areas are also found in tropical zones as on the-lee of trade winds on islands such as Puerto Rico and Hawaii. Wherever the briny lagoon develops, its faunas are characteristic even in temperate zones where cold seasons interrupt processes. Natural briny conditions are often associated with high turb.idities that are associated with poorly vegetated surrounding lands and flash flood run-offs. High organic levels also develop because of the generally poor efficiency of the simple system in processing organic food chains within the organisms. Bi4iny lagoons have low oxygen storage capacity and being enclosed 66 may be readily disturbed by wastes and other processes. A special domesti- cated version of the natural briny lagoon is the salina considered in this report as a man-dominated system. Blue-Green Algal Mats (A-7) Apparently occurring whenever marine waters are very shallow, a few inches in depth or less are the blue-green algal mats that form blue-green carpets of microscopic interwoven living threads over which winds wash waters that have 10 to 300 C diurnal temperature range, large salinity variations with rain and evaporation, and almost anaerobic con .ditions of oxygen content at night, contrasti ng with daytime supersaturation. Vast sheets develop in south Texas and in local areas in other states. The system has a few species of blue-green algae, water bugs, brine top minnows that can gulp air, and micro-organisms . The natural system makes food photosynthetically pore easily than it consumes it and much organic matter is left in the sediments. The system occurs in small extent as'the uppermost band in the splash zone' of rocky sea fronts. The mat system is also characteristic of many kinds of man-dominated waste systems. This is an example of the principle stated in the introduction. Systems adapted to natural stresses are often preadapted for invading man-stressed systems. B. Natural Tropical Ecosystems The characteristically tropical ecosystems are those'with low energy stress of salinity, temperature,'or other factors so that much energy of special adaptation goes into diversity and organizational behavior. These systems have many species., much chemical diversity in the many species, ani- mals that perform complex programs in their life histories and service to the system, and,br 'ight colors associated with these pr 'ograms. Low temperatures, and sharp seasonal programs are not required although specialists have species life cycles on seasonal schedules. We consider these in order of the proxi- mity to shore. The tropical systems have members which serve actively in cutting back the development of alternative systems. Thus fishes of reef habitats tend to graze back meadows that might otherwise be prominent. Mangroves (B- 1) Mangroves are marine-based forests which have special adapta- tions for roots in salt water, and in anaerobic muds. Some species cleanly separate freshwater from salt, after which the freshwater is transpired through their leaves as part of the drive for the system. Com- plex branching roots support a great diversity of marine animals and the crowns carry many terrestrial animals. In some parts of the world near great rivers or near great tidal shifts as in southern Panama the mangroves receive much salinity stre@B and their associations are not so diversified. In parts of southern Florida, in Puerto Rico, and in zones of Hawaii where mangroves were only recently introduced, tides and river shocks are less. Th e upstream damming of the "rivers of grass" of the everglades has increa- sed the role of the mangroves in the t ,housand islands of the lower Southwest coast where once freshwater discharges were larger and more erratic. Man- groves find their northward boundary with killing frost in Florida and Texas. The mangrove system controls sedimentation, andis a hurricane protection to some coasts. M 'angrove systems return to the water organic nutrients of special character producing special plankton associations, including luminescent and brown waters. ManEWove forests are used for 67 forestry purposes but mey have hi&.er value.in coastal protection and buffer purposes. Mamgroves are re,-.eiving wastes in Paerto Rico. Tropical Inshore Plankton (B-4) Because most plankton studies have been made in transient con- ditions in laboratories or in the strongly pulsing seasons of the temper- ate and Arctic regions, and because the high metabolic rates per gram and small storages in plankton give them rapid turnover times, plankton systems are often regarded as inhereatly unstable. In many tropical bays on dry coasts where they are not shocked with varying runoff conditions, enclosed bays develop highly diversified, incligenous, and very stable plankton populations. The phosphorescent bay of Puerto Rico is a famous example where the steady light of a-dinoflagellate phytoplankton species and its associated zooplankton have been continuously examined for many years,.with only an occasional interruption as with high tides of passing hurricanes. There are special nutrient requirements of specialized tropical phytoplankton which explains some of the means for diversification. T hus organic nutrients are important in such phenomena as red tides, in inputs from mangrove swamps, and the movements of laarger @ishes. The shapes of bays andtidal exchange rates are important to maintaining correct nutrient media. Of all the tropical systems these may be most sensitive to disturbance by turbiditieg enrichments, or modification of navigation channels. Coral Reefs (B-2) Long heralded as the most diverse, most highly organized, and aesthetically the most pleasing of all ecosystems, the coral reefs occuar in *vraters of bright sunlight, an,'- uniform'salinity e-nd temperature, and moderate wave energy ard curreitt. A coral reef is =-Ae up of anima.'@s that form skeletons of self-nade limestone and that incorporate microscopic photosynthetic plant cells borne on and within the tissues of the animals end rock structures in intricate symbiosis. Coral reefs are best developed in the U. S. areas in trust territories of Pacific islands, but small and beautifully diverse examples occur in Puerto Rico. Somewhat less developed reefs are found in the cooler waters of Hawaii and on the Gulf stream margin of the Florida keys where an underwater National Park provides protection. As reasoned in our introduction, the lack of stress leaves much energy for a variety of combinations and diversifications. One result of having more variety of species with special adaptations is rwre variety of systems. Within the general category of coral reef there is greater variety thanIn other systems categories where possible permutations are less. Because coral reefs are dependant on moving waters and on bright light, they are very succeptible to destruction by turbidity shading either from dredging or from microbial turbidity that may accompany nutrient fer- tilization. Although general features of coral reefs are readily described because of the great variety, there is less order and predictability avail- able about the details of coral reef management. There is a large literature on classification of coral reefs, most Of it based on areas outside of the United States* 68 The limestone substrates serve as a kind of soil and most of the animals have some means of eatiang limestone subst-rate for regenerative purposes. These adaptations hold the :,.,eef st-rorg in relation to current and wave and may be essential to the prevalence of the coral reef over some more inshore types. Tropical Meadows (B-3) In tropical coastal waters where there are soft sediments and usua lly in slightly deeper water than are the coral reefs, one finds the underwater meadows of turtle grass and other plants. 'The broad expanses of green mea- dows of vascular plants and benthic algae support a very high rate of production that is aided by the currents that accompany this ecological system. There are many bottom animals in these grasses including filter feeders that work towards maintaining plankton too dilute to be a shading competitor. In full tropical form the tropical turtlegrass beds-resemble the temperate eelgrass but are much more diverse., have little of the sharp seasonal cycling, and often develop Vhite sediments because of the pre- dominance of calcium carbonate precipitating animals like sea cucumber and urchins maintained in the grass syste-m. At its more northern zones in Texas the turtle grass beds resemble the eel grass more. Blue Water Coasts (B-5) The deep blue waters of tropical seas have a characteristic pattern of deep light penetration, sparse plankton-based food chains associated with a generally low nutrient availability, and some fast recycling of nutrients by tiny cells and many diverse specialists among the animals. Blue tropical waters of this type bathe the Hawaiian Islands, Puerto Rico and the southeast coast of Florida in the Gulf Stream. The blue water system has the stress of vertical mixing and low nutrient problems but has little stress in temperature and salinity or other ranges. Such waters become the province of this s==xy of coastal systems where lands drop off steeply into the sea and blue water flows along the shore. Except for the special condition of low concentrations of nutrients, the blue waters have less stress than most nlankton waters. With deep mixing, there are adaptive problems ofmaintaining plankton within the light zones. Although sparse in mass, the small plankton are in vast diversity with many shifting combinations possibly forming delicate adaptations to slight differences in conditions of these tropical waters. The lownutrient character makes these systems very sensitive to change by wastes. Fairly clear green waters from the opeh seas bathe other portions of the United States at other latitudes, but the plankton populations there are seasonally programmed, and different in character. 69 Natural Temperate Ecosystems Between the latitude in Alaska where winter ice phenomena are important and the latitude of southernmost Floridasouth of which seasonal changes in light and temperature become less important, are the natural temperate eco- logical systems which include the best studied estuaries and shores of the east and west coasts of the United States. Natural temperate systems are characterized by a shr-p seasonal pulse in both light energy and temperature, requiring adaptations for control of metabolic rates. The range of the pulse is greater as one goes northward to Maine and Southern Alaska. Characteristic of such estuaries are the blooms of plant activity in the spring with maximum photosynthetic production in the summer. A food source is the,considerable organic matter which runs into the estuaries from the rivers, and this flow also has a maximum on both east and west coast of the United States in spring and early summer because of the seasonal excess of rainfall over evaporation reaching its maximum then. Thus for two reasons the pulse of food available to estuarine ecological systems usually has a surge upward in spring and early summer. There are many subsystems of interest and importance such as intertidal zones, shallow plant bottoms, oyster reefs and clam-worm flats, that live off import of food in passing water and estuaries that are plankton dominated. The basis for each temperate system of our classification is discussed next. Tidepools (C-1) Where the spray of breaking waves and high tides elevate water up into irregular, rocky sea fronts, water circulation is maintained in perched tide pools in which small and often beautiful communities develop that have great asthetic value in the coastal economies related to recreation and the edu- cation of school children. The high and little varying salinities of the 70 cool waters flushing these pools provide a steady medium especially in those areas with much coastal cloudiness as in the Pacific Northwest and in Maine. In more southern locations with less tidal range, less wave spray and higher tepperatures., daily heating provides more stress especially of wide daily temperature ranges. Where stress is not large, however, the large, colorful, and delicate starfishes, anemones, aorms, and other animals form complex animal cities. These coastal systens develop slowly, are readily destroyed by pollutions or excessive-collecting. They serve as coastal indicators of the quality of the waters bathing the shores. The tide pool systems are restricted to the thin line of surf where rocky substrates are suitable. In the grand perspective of America's resources, the tide pools have values as wilderness zones for national park-type usage. Their complexity provides to the continental United States the type of diverse systems one associates with the stable tro@ical regimes in which basic studies of organization and behavior are possible. Theorists are now relating these kinds of studies to the Ceneral problems of behavior, structure, and maintenance of the urban cities. Some tide-pool tracts are thus needed in the research programs that r1timately concern'the principles of stabilization of our society for which suggestions as to special mechanisms are drawn from ancient examples of the sea margin. Bird: and 1 Islands (C-2) In some areas where there are large ranges in the pulse of the seats coastal productivity there are colonies of birds and marine mammals that concentrate in dense rookeries on isolated islands or rocks there providing for safety of young. The animals during Vaeir summer occupy a subsystem with some of the same role in the coastal systens as.migratirg fish, accele- rating food gathering in summer, draving large energies from the sea at the time excess energies develop. As the productivity system declines in autuirn, the yoiu-ig birds grow up and fly away., distributing their energy demands south- ward. The bird island with its foraging operations many miles in all directions is part of the regulation system of the coastal system. The large flying birds serve as nutrient concentrators, and locally the rookery locations have extreme- concentrations of nutrient fertilizer which may go back into plant growth systems either of nature or man. The quantitative magnitudes of these cycles are only now being calculated relative to their supporting system. The bird islands may not only be of aesthetic values in human coastal recreation but important and as yet, little understood in service as a control agent to prevent localized over-concentrations of smaller crustacea and fish populations. In the migration of birds and mammals equatorward in winter and back northward in summer there are the means by which there is coordination of the whole biological economy of the hemi- sphere. The problem of preservation and mainte-nance of this system of stabilization for wide areas of the coastal and offshore seas usually involves special consideration of the summer rookery sites. The ability of these consumers to switch to whatever is in excess makes this role possible. The question of pesticide concentration in this system is now under scrutiny. Landlocked Sea Waters (C-3) Mainly outside the scope of a coastal classification are the landlocked sea waters which can receive marine organisms physiologically, but being sepa- rated from population pressures, from the estuarine to open sea migrations, seasonal nursery pulse, and tide tend-to develop ecosystems with some fresh- water affinities and many organisms from salty lakes. These waters are mentioned as a source of information on the consequences of cutting off estuaries from the sea. 71 Oyster Reefs (C-5) Wherever there are strong current systems bringing'suspended material that may serve as food, filter feeding animals may concentrate into dense, exposed cities protected by hard masses of their skeletons. The reefs built by various species of oysters are the most common types, but reefs of animal consumers also include great sheets of mussels, serpulid worms and other animals. Oyster reefs are consumers requiring organic food in particulate form. The conditions for consumer reefs are very different from coral reefs that are mainly based on their use of light in photo- synthetic food production within their tissues. Oyster reefs develop in the intake pipes of industrial plants that use salt water for cooling, on bars where waters circulate in estuaries, on the sides of rocks, on pilings, or on bottoms of ships. Because of their concentration of life and structure the reefs have been of great importance as food for man, and the shells have become important in calcium carbonate industries such as road building and co---icrete manufacture* The management of oyster reefs has not always been made with the understanding that the reef is based on the continuous circulation of a much larger area of water than that over the reef itself. The planktonic farm and the organic matter from rivers that contribute support to the reef are large in volume. The foods dispersed in a bay are controlling the amounts of reefs. One cannot manage a bay for oysters without managind the inputs of suspended foods and the release by oysters of minerals that return to the plankton as a necessary step for growing more food for the oysters. Because oysters are built with shells, have wide salinity tole- rance, and abilities to suspend operations for long periods., they are adapted to great variations in water level, sal-inity and temperature in the river mouth estuaries or in the intertidal zones. Where stresses are less, more diverse communities replace the oysters,, doing so by spread of drilling snails and action of diseas;s that eliminate the oysters, as the condi - tions; become stableenough for the competing communities. Although the diseases and carnivores are often the agentsof replacement of oysters by more diverse ecosystems-in the @ourse of-a season or in year to year changes, the ultimate causes are related to'the changes in regime that allow ..-more stable, higher salinites and more uniform temperature conditions that foster the complex systems. The management of oyster reefs has to be related to the,programming of river control, towards maintaining oscillations, and insuring adequate volumes of suspended food particles. Leasing bottoms may not be enough to provide.good management, unless the whole bay system is leased and managed as it is now done in a few states. Salt water mussels form enormous reefs especially in northern latitudes where they hang on the rocky substrates. Since they form rigid structural mats of animals, they too are consumer reefs. Among the most interesting of ancient geological records are those left by ancient consumer reefs that 72 begin now to yield their information about ancient estuaries as we learn how to interpret,the whole estuarine systens interactions from the nature of the fossil reef subsystem. Marshes 0-4) Where there are broad intertidal flats of soft sediment not too strongly stressed with waves and winter cold) grassy marshes develop in the estuarine salt waters that flood the grass usually twice a day leaving the systems standing free in air part of the day. With green vegetation out of the water, but with roots in wet rich sediment) marshes are among the most productive of organic matter of all systems. The alternating tidal exposure does have some aspects of stress requiring spec 'ial adaptations. Marsh grass and the animal populations of oysters, snails, and fiddler crabs are capable of maintaining both submerged and emergent existence. Many special adaptations exist in the marsh. For example, some tiny microscopic diatoms burrow into the mud when the tide is in and then surface on the mud during outgoing tide there receiving light for their photosynthesis. The phenomenonturns black mud a golden brown within minutes as the cells emerge. The marshes have been shown to export much plant matter to the estuarine waters where slow decomposition begins'after which the soup of organic food supports much of the food chains. Consumption by clams, oysters, and shrimp remineralizes the fertilizer elements which are released to the marsh grass completing the cycle. Recognized now by a court decision.in Massachusetts, the marsh is an inherent and necessary part of many estuarine ecosystems. Removal of the marsh would be tantamount to removing the most productive part of the farms from a system of farms and cities. Marshes increase in importance southward in the United States because the coastlines of inter- mediate tide and wave energy and other factors of geological history develop broad sedimentary platforms. Winter stress on intertidal zones is also less and although the tops die back in winter, the root systems are available for a fast spring growth. With thetr productive structures above the water, these systems may have more capability for survival under some waste stresses and thus may have more capacity to serve as self-purification than some other systems that are dependant on clear water or are not already adapted to some stress. The patterns of two main types of grass Spartina and Juncus are almost universal on the east coast. A Salicornia predominance exists in many west coast marshes., most of which are relatively small in extent. In the ice stressed estuaries of Alaska some other types develop. Worm and Clam Flats (u-6) Animals that provide for their security by burrowing in flat areas of sand and mud may predominate the area and develop characteristic subsystems based mainly on the particles of food that pass by and are then filtered. These flats may be intertidal or permanently submerged. Like the oyster reefs they are usually dependent on the food in water of a much larger support 73 area that passes aver the flat and is then filtere:d by the clams.,and worms. In our classification, we may find @ya and other clams in two places; one as a clam flat subsyst6ft when considered aione, or as one component of the deeper estuarine systems in which the bottbm is!.,a contributor but not dominant. Some microscopic plant contribution to food may come from the flats themselves when they are close to the surface receiving considerable sunlight, but they are too stressed for benthic plants' of larger size, The commercial Nereid worm flats in Maine may be of this type. Clams with long input-output siphons such.as, &a arenaria areespecially adapted to the intertidal zones which have temporary surface stress. Thus the Mya predominate in niorthern flats that have strong freezing winter winds between tides. Deep siphoned clams are also found in very shallow mudflats of Texas, where the surface muds become very hot for a few hours,, but the deeper muds remain cbol.. Long siphon surf clam4 Spisula,ar6 part of the subtidal beach zone system where the long siphons allow the clam to live below the,zone of greatest sand disturbance and thus to avoid being un- earthed and broken. Kva with ability to take salinity stress also is characteristic of the oligohaline zones. In southern regions the oligohaline zone is partly dominated by Rangia which lies on top of the mud in enormous numbers, its protection from an extremely heavy calcium carbonate shell instead of from a thin shell and a long siphon. These two species occur in enormous numbers and ate a major re- source. Adaptations to respire without water pumping are part of the special requirements of the intertidal flats. The big worms carry haemoglobin and the clams have means for use of oxygen in airs In the extremely stressed intertidal zones of the north or of the upper estuaries low diversil.-Y populations are almost entirely of one or two species. In the more stable high salinities of coastal waters further from river surges) the diversity overall is large but there may be-local beds of one species, a specialization phenomenon discussed in the introduction. Because the filter feeding clams are related to the natur6.,6f the passing planktonic food or detritus, and also have adaptations that reflect special stresses, they may be used as indices to classify estuaries of which the clam beds may be only a subsystem. Eelgrass and Benthic Algal Bottoms, Shealow Salt Ponds (C-7) In shallow waters with good current, where salinities are high and little stressed with river surges or light-absorbing turbidities, a bottom system of dense bottom vegetation develops with blades of grassy eel- grass or bottom algae of massive type. The heavy beds of underwater vegetation wave and weave in water currents providing some of the highest known photosynthetic food production situations in the sea. The currents assure necessary nutrient inflow and waste removal from the blades. The 74 association of animals and micro-oi-ganigms is conplex and varied as one expects when energy.input budget's are high and when stresses are small. Eelgrass beds are fo'Luad the world arounc@ being imortant on both coasts and Alaska. Differences exist with some substitutions of fauna in niche roles. In Alaska., for example, herring deposit eggs on the eelgrass, and their larvae may shelter in the e6lgrass beds., whereas the safety of herring reproduction on the east coast is insured with schooling behavior and the return flows- of larvae of coastal gyrals. On the east coast there was a widespread demise of eelgrass beds in which a fungus disease was implicated thirty years ago@ but in the last 15 years it has been coming back and is often again a major system or subsystem. The disappearance did not take place on the west coast even though the disease organisms have been shown to be present in the beds. many scientists believe the disease agent was not the primary cause of stress that allowed the eelgrass to be replaced'.. although it may have been the agent which went into epidemic state when the condi@ions for effective eelgrass were stressed. One possibility is the increase of turbidity of estuaries as 'sociated with the cutting of eastern forest, poor agricultural practice and soil erosion, which may have reached its peak at the time,of the economic depression., the time of the eelgrass die back. As pointed out by Nelson Marshall most eelgrass is accompanied by some clams or filter feeders' (such as bay scallops) that may have an important role in clearing the turbidities from the waters so that high production of the grass can support a large microbial population decomposing the grass and in turn supporting a high density of filter feederse Heavy benthic grass beds in upper estuaries have freshwater plants like Valisneria, and in the Gulf regions the eelgrass beds are replaced with more tropical plant domi- nants like Thalassica although the general characTeristics of the complex associati on of animals in the beds are more those of the eelgrass than that of the tropical grassy meadows. This may be related to the sharp seasonal program that exists in the productivity system in the Gulf requiring animals with strong seasonal programming, The benthic plant systems occur in isolated shallow bars in deeper turbid bays,, as continuous communities in channels, and as the main pattern in salt ponds(as in southern New England)in which the inflow and outflow of tidal waters organize the patterns around the fan of spreading tidal distributaries. Oligohaline Systems (C-8) Studies the world over have shown that the minimum diversity of species is found in river estuaries in the zonee where the salt ranaes from fresh- water- to a few parts per thousand. It is not this particular salinity that is the species res-cricting stress,, for there are special estuaries of this salinity in Florida and elsewhere in which the waters are spring fed and very steady. In these estuaries great diversity does develop with complex mixtures of animalt one might otherwise regard as marine and animals one regwdsas freshwater types. In the usual estuary the 0-5 to 8 partsper thousand range is the zone where there is the most fluctuation of irregular surges of river water during high rains followed by surges of salt water 75 back 'during exceptional tides and low river discharge. In northern lati- tudes there is the additional stress of very different land runoff tempera- ture contrasting with less variable maxine waters. The oligohaline regimes thus are fluctuating regimes with only a few species of plants and animals. Clam bed and subsystems are usually important. The deep digging Yjya clam dominates in the north and the heavy shelled Rangia dominates the oligohaline zones to the south. In a state like Louisiana with predominant phenomena of the large river discharge of the Mississippi the oligohaline,regime is the main estuarine phenomenon and Rangia clams are the main animals inshore from the better known oyster reefsthe latter marking the seaward margin of the oligohaline zone as we define it. The oligohaline regime has some freshwater and s,ome marine fishes participating especially during temporary period of salinity stability. Medium Salinity Plankton Estuary (C-9) Also Mixed Salinity Plankton Estuary The image most people seewhan one says "estuary"is the medium sa- linity, moderate depth bay, which has much fishing but not much visible evidence of anything else. The bays draw support from food chains of in- visible microscopic plankton supporting the characteristic populations of crabs, fish, and commercial shrimp. Many of our largest estuaries are pre-' dominantly of this type although they are often fringed and bordered by smaller subsystems of other types. High nutrient levels and good stirring mechanisms generally produce high photosynthetic rates wherever clarity of water is maintained although it is.less than in systems like the marshes .that have less water to absorb light. In winter., with low light,, and well stirred waters due to tidal shifting and some turbidity from rivers, the plant cells spend too much time in the shade and stop making much food. In the spring as light conditions increase; the critical condition at which the plant cells can make a net gain is reached and there is a sudden bloom of some of the diatoms that sets off the seasonal production sequcnce. During the winter there is organic par- ticulate food remaining from the previous season, from marshes., from rivers) and other storages that keep some of the animal life going. With the rising burst of plankton growth there are some releases of larvae from clams,, oysters and barnacles., and little water-flea-sized copepods develop. Acartia predominates this system throughout the,east coast. Middle salinity examples documented on the'West coast with Acartia copepods include the Yaquina (Frolander,. 1964), the Sacramento -San Joaquin Estuary (Kelley, 1966), and others. Re- productions dnd migrations of shrimp and fishes that eat the zooplankton are timed to coincide with the increased yields of these small components so that the rise in stocks and consumption takes the rising production, most of which is entirely invisible to the man in the boat aboVe unless he. measures the phytoplankton., some index of its activity such as oxygen pro- duction,, pulls a zooplankton net, or has some way to estimate the rising stocks of fishes and shrimp. The middle salinity estuary has species with some ability in their kidney systems to deal with salinity fluctuation, some ability to switch food intake from organic matter to plant plankton base, and an effective temporal program for migration and reproduction so as to hook the need for more food to the timing of appearance of more food. 76 Whereas the bottom clz3msand the special'subsystems of the bay margins are contributors, the main system is one of plan1fton and plankton eaters. As the sunlight begins to decline after Ju.'Ly, the population growth and reproduction declines and soon many populations migrate out again decreasing their load. Because the source of energy of this system is in microscopic plant plankton, from invisible organic contributions from the rivers that support bacteria as intermediates) and from energetic services of tidal currents, rarely do persons not trained in marine science understand the basis for this system and its management. The food chain is out of sight and thus out of mind. The need for maintaining effective plankton populations is not understood by the untrained resource manager. Since all the specie-s draw from some cf the same energy pools, rises in or falls in one species must be accompanied by compensating changes in others. This system like the others must be managed as a whole, not species by species or with commercial fish separate from sports considerations, etc. The medium salinity estuaries often have partial stratification with wedges of dense salt water underneath. In systems allocated to this type., mixing is adequate to prevent anerobic conditions from developing at the bottom even though oxygen is less there since respiration is more at the bottom of the estuary than in the top water. Estuaries tend to be deeper as one goes north,, but also the amount of tidal energy available for currents and mixing and eddy diffusion coefficients increase@ Sheltered and Stratified Estuary (C-10) Most of the estuarine systems have strong tidal or wind-wave circulation that serve the communities by doing necessary work of circulating materials: moving the needed carbon dioxide and nutrients to the plants, needed food particles to the animals, needed surface oxygen to all concentrated sources of consum-otion and decomposition down below, larvae from sources of repro- duction to sources of larval feeding, animal populations from summer situations to winter locations, etc. Stirring systems thus are used by adapted species as auxiliary energy sources to do jobs they would have to do for t@emselves. In the absence of the circulation they either survive in reduced numbers or are replaced by slower operating species which can operate in the less energetic situation by requiring less. The stirring currents can also be a source of stress when they move populations from places of support to places where they are not adapted. Experimental studies show that there are optimum rates of circulation and that too much energy leads to loss of diversity and ability to develop as much production of living work. Due to geological events in the formation of the estuarine margins,, some bays are sheltered from winds by being small or thin and crooked in shape, so that winds cannot build up much wave action. If the bays also have a shallow or narrow mouth large tidal flows cannot exchange much water 77 into the bays and relatively stagnant estuaries develop, which may exhibit the vertical stratification one associates with a fertile lake, a system with an upper oxygeiiated layer and a low oxygen subsystem belaV4 dominated. by a microbiological decomposition pool for at least part of the year. There are not many of these systems but the ones that exist are of con- siderable importance in indicating what is possible when these kinds of estuarine effbayments are constructed. Many of man's actions in changing circulations inadvertently, in dredging channels, in diking estuaries for power or water storage, and for other purposes are making new systems of this type. Stratified systems are much more sensitive to pollution effects than the better mixed ones. A fiord is a narrow deep channel cut by a glacier originally and now invaded by the sea. Fjords are one of the kinds of basins which may have restrictedpirculation and stratified estuarine type of phenomena. Some of the best, data come from Canada and Norway. Kelp Beds'(C-11) At depths less than 100 feet s eaward of the surfzone or in high salinity embayments where there is some swell and clear water, giant brown algae grow as vertical-standing., underwater forests that wave and lash with the sea motion, supporting a productive plant production at the top and a very com- plex and organized ecological system. Kelp 'systems have maximu.m-development in cool waters of the west coast with Macrocystis. In the Atlantic Laminaria fills the kelp zone. Chapman (1964) summarizes studies by F. T. Walker giving weights and cover of these beds. Thisstudy is possibly pertinent to appraising the system in Maine. The kelp is cut and harvested.commercially on the west coast. In Maine the associated red alga Chondrus cris.pus is harvested.commercially. The controversy developing about the effect of pollution or urchins on Ir-elp has led to many scientific studies and some experim3ntal attempts to pro- tect the beds by dropping flaked quicklime on urchins. Ecological con- siderationd at the ecosystem level may not have been adequately considered so far in this work. An inherent featxtr,3 of the undisturbed kelp system are large specialized fishes that are supported on well channeled food pathways from the kelp, but which have the tendency to eat and remove those mcnbers that are dangerous if too abundant in the kelp system such as urchins. On the other hand urchins form a system with encrusting algae and while supported by encrusting algae have a tendency to eliminate the kelp system by eating the bases so that the kelp stands float away. In effect each productive system has special members it supports which exert nega- tive and competitive actions on the other system in such a way as to favor its own system. If pollution stresses the special fish consumers of the kelp bed so as to eliminate their action, then the urchin systems may dis- place it even though the waste action on the kelp plants is neutral or stimulatory. As in so many other situations ' stresses that work against the control systems displace the large and complex system types in favor of the simpler systems that rely on rapid replacement instead of organization. The kelp beds have importance in their own beauty, as a system of potentially greater harvest, in their contribution to coastal productivity, and in their value to the understanding of competition of whole systems through interaction of their top food chain animals on adjacent systems. 78 Neutral Embayment and Shorevaters (C-12) Washing the outer archipelagos of Maine and Alaska, into the zones at the mouths of some of the largest estuaries,and along zones of Florida where there is little freshwater discharge are plankton waters of the Neutral System. In the Pritchard salinity classification, an estuary without river inflow or without an exce ss of evaporation was said to be neutral, one in which a bay is filled with water exchanging with the open sea without salinity change. Neutral embayments and coastlines with steep fall-off have waters that move iii from the sea without much modification except that the waters have no longer the deepscattering layer migration and have a bottom below. Also at the coast waters receive a different kind of vertical stirring as tidal wave energies are absorbed among islanc6-in channels or reflect-off shores. The neutral system is a high salinity - has more diversity than most estuarine systems, but plankton system that is dominated by recognizably different species. With clearer waters than most estuaries, the photosynthetic zone is deeper, and variations in salinity and temperature are less. The neutral waters are close enough to be affected markedly by land influences such as waste outfalls should they develop. The neutral system in such instance is readily transformed into a new type. With more stability of temperature and salinity due to the depth and sources from the open sea, neutral shorewaters probably have the highest .diversities and complexity of components of coastal plankton systems of the temperate latitudes. 10dereas high diversities tend to favor little mass and yield of any one component, the phenomenon of local species cities ind the movement of the high pulse stocks of shrimp and migrating fishes of the estuaries back into the high salinity zones,, make commercial concentrations available there too. The coupling of a stable salinity system to a pulsing one leads to pulses in both. The coastal neutral waters are also the zone of migration of coastal fish migrations northward in the spring and early summer and back in the fall, supported in the southward migration by the populations emerging from the bays. The neutral system is thus a giant switching system of the network of food distribution and processing of the planetary migration with estuarine system in which man's small trawlers participatee 79 Natural Arctic Ecosystems The coastal systems of the far northern latitudes receive heavy stresses over much of the year from ice phenomena and receive photo- synthetic energies for only a short period in sunmer. With more light and photosynthesis on land but more winter stress, much of the production of the land is not processed there on the land but washes into the sea before processing. Ecological systems develop in, on, and under ice and in the fjords associated with the glaciers. Those systems of Alaska with ice phenomena predominating their regimes are grouped as Arctio. The other systems of southern Alaska are variations on temperate systems also found' further south. Those Alaskan fiords without glaciers or glacier fed rivers were classified with other neutral embayments. Glacial Fi (D-1) Many of the glaciers of southern Alaska terminate in the estuaries where they carvesmall and large blocks of ice and directly discharge much matter enclosed in and on the glacier. Waters are blue. Some features of this situation apparently lead to large populations of marine animals at the base of the glacier. Meltwater tends to form a freshwater lens over the top of the estuarine system, but the saltier waters below do*not ordinarily develop low oxygen because of the high tidal exchange that takes place below the surface lens. Turbid Outwash FlMds(D-2) A different type of ecological system develops in fjords that receive turbid rivers from glacial deposits where the glaciers end on land. Heavy sediment loads affect the densities of the inflowing meltwaters, which are heavy enough to mix downward irrto the estuarine system producing a different pattern of circulation --nd exchange. Ice Stressed Intertidal Zone (D-3) In the Arctic and subArctic the intertidal zone is stressed by freezing between tides where waters are ice. free and by the thrust of sea ice. The high energies of winter waves evd tide from the Aleutian center of cyclonic low pressure pound the intertidal zone in@vinter on high tide, and strong subfreezing winds stress the zone between tides making impossible much , intertidal life through the winter. Summer conditions permit development of algae and small sized populations. on the north side of Alaska the*sea ice scours the coastline. Sea Ice (D-4) Sea ice harbors life. The freezing and melting of ice and snow develops nutrient concentrations in and on which algal blooms develop. Large memmials may also make contribution. Algal associations are on the underside of floating ice with interesting photosynthetic production in low light intensities, 80 The ice provides a form. of stability to its underside, including nearly constant temperature and protections from wave action, wind stress, etc. Under Ice Plankton System (D-5) . In Arctic seas on the north and vest side of Alaska covered for the most part with sea ice, light is low in intensity and short in season, but plankton populations do develop regular-patterns and good chains. At low temperatures organisms have less thermal stress so that structure is easier to maintain and under the ice there are fewer disruptions from waves and changing regimes of wind and temperature. Characteristic of these systems are the large mammals among the ice floas. The cover of ice provides special temptation for the disposal of wastes, discharging under the ice-- something like sweeping dust under the rug. With the further development of Arctic industries such as those related to new petroleum discoveries, more will have to be learned about the ice-topped shallow plankton seas. Ewrging New Systems Associated with Man At this stage in classification and study of emerging new complexes of pattern associated with characteristic wastes and disturbances.by man, we caninolude only those types that have been studied enough to identify the presence of something new in pattern. No doubt the number of emergent new waste types will grow with efforts to identify them as well as with the spread of industries. Although,the types of waste and disturbance, which are changing the estuaries of America are of many types, most of them appear together in multiple waste channels* There are relatively few types other than the multiple-waste estuary. Apparently decisions as to location of waste outfalls by towns and industries have been much influenced by the presence of oiher waste outlets. With passing patches of man's effluents the mixtures'might seem to be of endless variety. However, the alternating shock of contrasting chemical solutions do develop some common properties of high stress and low diversityl even though different kinds.are representeds Sewage Waste (E-1) The discharges of rav sewage and the rich effluents from primary or secondary treatments inject high levels of organic matter and enormous increases in the trace nutrients required for phytoplankton photosynthesis. The nutrient ratios of such elements as nitrogen and phosphorus in the wastes of a city have some basic properties which vary depending on the industries using the some effluent system. These wastes tend to support both producers and consumers of types different from the@unmodified system. The small red annelid worms at the end of ocean outfalls of sewage are one characteristic pattern. Although more attention has been paid to the survival of disease organisms in affected estuaries than to the nature of the emergent new system, the growth of cities vill. tend to convert more and more estuaries to a type of system compatAble with these flows. Case histories already studied produce bases for characterizing these emergent systems. 81 Seafood Waste6 (E-2) Wherever fish and shri-mp are landed and processed for food there may, be wastes frorh the processing which.enrich local waters and produce blooms and varying oxygen conditions. Since the wastes represent components from the sea, the return and decomposition represent the same kind of processes that would have occurred without the food harvests except thatthese, releases are much more concentrated than the natural patterns and regenerative cycles trach more' Irregular in discharge. Pesticid6s @E-3) The vi ae &-Istribution of pesticides is well documented, but the kinds of ecosystems one gets when the levels are relattively high is only now being learned although some,extrapolatio'ns of laboratory data can be made to predict th@ gysteme Most of the case histories available show disturbance of a system, but not as yet a�e there cases vhere the effect so dominates the system as to-chdrge its main characteristics. Dredging s@oil (E-4) Dredging changes depths and releases large volumes of sediments and turbidity. A number of case histories can be cited on the nature of artificial dredging effects, many of which resemble the natural patterns in river mouths. DWoundment (E-5) Estuaribe system types change when circulation Is reduced or when 4- access.6f the sea it eliminated for purposes of converting estuaries n@o f@eshi4ater lakes. The reduction of wave and current energies eliminatte estuaries of known valuable.type. Recognition of the chan ged.system may help in appraisal of the nature of the new type. There are closed systems vith.vater composition like that of sea water which accept marine faunas and devel6p useful ecological systems after seeding and introductions. The Salton sea is one case 'often cited where new designs are developing new systems in waters cut off from the sea. Not the least of the changes is the elimination of migration. Thermal Pollution (E-6) The-advent of nudlear-power draws much attenrion to the systems which develop where sea waters are drawn into cooling pipes and returned to bays. Whereas the patterns of low species diversity and physiological adaptation ari veil established in.,studies of natural hot springs, the patterns in the cooling water axe complicated by variation in rates, by@ variations and interactions with adjoining systems of older types, Thus the several situations already in ekistence are studied carefully for some indication of the type of ecological systems that may prevail. Two natural situations of 82 temperature variation are the hot salty ground waters discharged from oil TAells and the fluctuations in tem-Derature,lowering diversit3i in the Cape Cod Canal in Massachusetts. PulpmIll, Waste Systems (E-7) In quantity and volume the wastes of preparing wood for paper are vast on all coasts with many estuaries dominated by release of organic materials fiber, and chemical waste from processing. There are the organic substances diffusing from wood rafts in Washington State, the river bottoms of Maine with sawdust sediment,, the lignin by-products from the paper processing, and the sulfites and other chemicals which have toxic aspects. The separate laboratory test of components have long been studied, but the overall behavior of an estuary dominated by this 'influence is not easily documented. It Is not clear, for example, if the microbial food chains based on the organic matter lead"to higher food chain'productivities or not. The fresh- water zones of such rivers sometimes acre dominated by growth based:on soluble organics such as Sphaerotilus, vhich-forms fungus-like bacterial colonies that densely drape all su ces'. What really happ@ns with this 'slime in the estuaries is less clear. Sugar Cane Wastes (E -8) With sugar cane the soluble organics are not released, but the fiber, vash waters, and much mud entrapped in sugar harvesting methods are some- times flushed into clear waters of tropical coasts.-i4here turbidities are incompatible and disturbed systems result. Whereas turbidity injections from freshvater plumes are a regular pattern in moist tropical coasts, the waste into stable complex systems provides a different permutation. Phosphate Wastes (E-9) -The mining of calcium phosphates from sedimentary deposits involve& much processing of overburden soils. Waste waters have slimes with con- siderable fluoride, phosphatic content, end turbidity. If there is refining there may be other wastes Vnich are acid with very high dissolved phosphorus and fluoride concentrations. The systems developing where phosphate wastes are released may have changed nutrient ratios relative to phosphorus and shading of turbidity. Estuaries associated with Peace and Alafia 'rivers in Florida and in the Pamlico ar ea in North Carolina provide examples. Acid Waters (E-10), In freshwaters of states like Pennsylvania, a characteristic pattern of acid waters results when oxidation of sulfide deposits produces sulfuric acid. In our aea grant ponds at Morehead City, North Carolina, exposure of salt marsh muds to the air produced a similar acid condition in ponds with carbon dioxide driven off. Special phytoplankton developed which were 83 adapted to fairly hard buffer systems and had little available carbon source, except free carbon-dioxide being released from animals. A charac- teristic plankton developed like that in fresh waters. Acid releases from industry or fici,n mining are likely to generate this pattern, veil known in freshwaters of Pennsylvania. Petroleun Shores (E-11) The frequent 61lls of' petroleum have provided many examples of a special oil shore ecosystem, the best studied being the Torrey Canyon spill in England. Floating' oil ends up on beaches and other shores where microbial processes carry out decomposition especially if other nutrients needed by the bacteria are present, Related to the petroleum is the pktern of toxicity and phosphorus fertilization from' use of detergent to disperse oils. Oils are released from marine systems to the surface in slicks as a normal process, but the petroleum spill,is vastly different in q7aanluity. The action in stressing large animals, in forming toxic sludges on the bottom, and in permeating flesh of animals is well documented. Where spills are frequent, the pattern developing becomes a regular eco- system of a new type. piling (E-1p) The introduction of wood piers and piling constitutes the creation of a special ecosystem type with shipworms and boring crustacea. Even with heavy creosAe- and other chemical treatments, characteristic boring animals such as grib"ble (Limnoria do develop and apparently can consume the wood in this state. Setting 'of intertidal barnacles and other organisms on the Outside tends to be feVer in number and type. Estuarine piling. is a special system of man. Salina (E-13) The sequence of evaporation of sea water to form salt follows procedures ihtt have been with man's culture for hundreds of years. Man's special arrangement of estuary.flovs for this purpose constitutes a special eco- system. A_,steady state pattern of inflow and.removal involves a'rotation of treatments to a sequence of ponds. The arrangements for processing the water by man'make distinct differences in the system as compared with natural briny lagoons that form otherwise in such climates. Brine Pollution (E-14) The flow of brine waters either from industry, from.vaste of extracting freshwater from sea water or from ground waters up through oil wells constitute a special condition. The brines have different ion ratios from sea water especially in having different cation ratios and often are laden with iron and other dissolved substances. Brine waters from inflows of this type differ in organic content from that developing in briny lagoons and salinas. Flowing brine water is dense and constitutes a stress where it fluctuates over normal bottoms. 84 Petrochemicals (E-15) The refining of petroleum prod-ucc-s vastes of raixed organic compounds., and usually with refineries are located complexes of industries which use the various petroleum components in plastics-ancL other manufacture, producing additional organic wastes, many of which are toxic. The mixtures of these wastes concentrated in small:lagoons produce black waters, anerobic conditions, and very low diversities of biota generally. Tiess known is the pattern of ecological systems one gets when petrochemical wastes are dispersed into estuaries in more dilution. Miltiple Stress (E-16) The most common disturbed system in urban America is the city harbor or upper river estuary which has ocean shipping, wastes from cities, industrial wastes of many types, dredging of bottoms, pftrtbial empoundments interrupting circulation and injections of thermal cooling waters. Diversity of species is small, larger animals are rarely in evidence, and chemical sensors and analyses show .. peths pf.contrasting waters drifting by, providing sharp shocks to all living prganisms including the fouling communities on ship bottoms. Showing that a nearly dead ecosystem goes with multiple stress is no trick. The,.real question is to find some kind of adaptatigns that can function. F. Migrating Subsystems To the energy support cycle are coupled regimes of micro-organisms and animal activity rising with the euergy availability. A characteristic adaptation to the seasonal regime that per,-V.4tS the rapid spring rise of animal populations is the release of microscopic larvae at the time of the phytoplankton blooms. Then there are migrations of populations of larger animals swimming or s we pt into the bays during summer from the rivers or-from the open sea. Commercial shrimps, herring-like fishes, shad, and salmon make their famous'migraticns and may have the one common feature that Ithe population's new young find their period of most rapid weight addition while in the estuaries, thus taking advantage of the pulse of food inthat'system. The general concept of the estuary as a "nursery it concerns the fast growth of newly hatched young rather than the actual reproduction. Egg production is often done in an area of safety as with saLmon far up small stre-ams where live eggs are stored in stream gravel@ over winteror with shrimp and mullet spawning in stable temperature and salinities seaward in such a way that the young are drifted back into the estuaries. In other instances the eggs are released within the'same estuary where the nursery function may develop. The important generalization about the estuarine migrants in the temperate systems is that a stock will con-: tinue to dominate the estuary as long as its programs of reproduction pro- vide enough new young to takemaximum advantage of the estuarine Pulse of available food energies in the spting-summer season. In one sense the migrating subsystems are the principal means for organizing all of the sea's systems into a coordinated whole. 85 Part II FORAMINIFERA IN ESTUARINE CLASSIFICATION Maynard M., Nichols Virginia Institute of Marine Science Gloucester Point, Virginia 23o62 Among the various microconsumers of estuarine bottoms, foraminifera provide useful clues for the energy classification of estuaries. They not only participate in the cycling of organic materials-but also ace,-Umulate energy in the form of protoplasm and a calcium carbonate shell or.test. Because their tests are well-preserved after burial in sediments they have become a diagnostic tool, long used by oil geologists, for classifying ancient strata and recognizing oil-bearing deposits. Foraminifera are especially useful for classifying estuaries because they live in nearly all systems from fresh water to the continental shelf and beyond. They form distinctive groups.,possessing certain adaptive char- acteristics, in different types of estuaries. Therefore, each estuary has its own characteristic fauna by which it can be recognized. Furthermore, foraminifera are fairly abundant, easily collected, and readily identified. Because of their utility a wealth of knowledge has accumulated on their taxonomy, their distributions and ecology. As a result foraminifera are better known than any other widespread estuarine group. The purpose of this chapter is to show how they can be used to classify estuaries from which'more refined information on estuaries can result. LIFE AND ACTIVITIES OF FORAMINIFERA Foraminifera are microscopic unicellular protozoa that develop a test composed of calcium carbonate, agglutinate sand particles,(arenaceous) or occasionally, organic chitin. In estuarine areas they live on or near the sediment surface and often attach to benthic plants. Growth of the test leads to formation of chambers which are arranged in a multitude of dif- ferent forms. Often, end chambers are contorted under stress-conditions. Foraminifera gather food in protoplasmic nets extending around the tests, a feature which distinguishes them from other amoeboid protozoans. They trap a wide variety of algae flagellates or bacteria and cram them around their test or into an aperture through the test. Although pennate diatoms are among the most common food, different species have specific food requirements (Myers, 1943). Not only the type of food but the amount of food are of importance in foraminiferal nutrition (Bradshaw, 1955). In experimental cultures Lee et al. (1965) found that foraminifem are "bloom" feeders. When law concentrations of food are.present forams eat sparingly and reproduce slowly, but when food is abundant as in a bloom, they exploit it. These results are supported by a few observations in estuaries - for example M. Buzas (1969) found a-periodicity in species density in the 86 Choptank River, Maryland, with relatively high numbers during periods of high chlorophyll content. Myers (1942) found foraminiferal growth increased during a phytoplankton bloom and furthermore the chambers added were longer, and thinner than when food was scarce. Similarly, Waldron (1963) found a spring "peak" of foraminifera in Timbalier Bay, Louisiana, presumably related to the amount of land-derived organic nutrients (Fig. 1). Although such temporal studies are few, they do indicate that foraminifera may be sensitive to timing of energy sources as freshwater inflow. The life span of foraminifera ranges from a few months to several years. E. Myers (1943) found that the life cycle of the cosmopolitan species Elphidium crispum in tide -pools of temporate regions is completed in two years, whereas below tide level 3 to 4 years are required. In tropical water by contrast the span is six months and a life cycle is ccm /pleted in 'one year. In the life cycle there is a succession of sexual and asexual generations. Reproduction terminates- the life of both sexual and asexual individuals and this feature provides a means of determining the annual productivity. The work of Myers (1943) and Glaessner (1967) are the chief sources of information on the life history, habits and activities of foraminifera. FAUNAL FEATURES- To identify different estuarine types it is useful to organize distri- butional data under the following faunal features: 1. Number of specimens or abundance. 2. Number of-species and diversity. 3. Shell characteristics and composition. 4. Number of planktonic forms present. 5. Faunal composition. Abundance The number of living foraminifera, at any particular time should indicate the general level of organic production from estuary to estuary. Within one estuary, the abundance of foraminifera should point to local sources of energy supply. An estuary having very low standing crops, e.g. less than 10 specimens per 10 ml of wet sediment as in closed San Miguel Lagoon, Baja California (Stewart, 1958), is regarded as low in fertility and low in organic production. By contrast an estuary with relatively high standing crops, e.g. more than 1000 specimens per 10 ml as in the thin grass areas of Laguna Madre (Phleger, 1960b), has high organic production. Between these extremes, standing crop size alone is not an adequate index to fertility or to the rate of production. The growth rate and frequency of reproduction of a population need to be determined. Except for a few studies, i.e. Myers (1942) and Boltovskoy (1964), these factors remain to be determined in most areas. Although foraminifera make up only a very small amount of the total benthos (less than 5% of metabolism, Horton, 1961) and less than one percent of the total bulk volume of sediment (except in some coral reefs they may make up more than five percent of the sediment) they are often abundant in areas where food supply or plant nutrients are abundant. For example, large populations averaging 500 - 2,000 specimens per 87 Octo6er STATION 6 LEGEND 11- Ammotium dilaia@um C - A. fragile September N D- A. 8FISUM E - Elphidium gunteri F - E. limosum G - E. maiagordanum ) - Miliammina fusca August K - Streblus parkin8oniana L - S. (epida N - Others 6 individuals per species or less July . . . . . .. June May Apri I ------------------------- ---------- - March ----------- ------------- III Fe6ruary January 0 100 150 2 ?0 Fig. 1. Monthly distribution of foraminifera in Timbalier'Bay, Louisiana. From Waldron (1963). r 88 10 ml are recorded by Uchio (1960) off San Diego in an area of nutrient-rich upwelling. Populations of 1,500 to 3,000 per 10 ml occur off Main Pass of the Mississippi Delta and also off the Guadalupe River at the head of San Antonio Bay, Texas (Phleger, 1964), areas where river-borne nutrients are intro- duced and mixed with marine water (Fig. 2). Interestingly, the large populations are dominated by 1 - 4 species and specimens are typically of small size, features attributed to rapid reproduction of large populations under optimum conditions (Phleger, 1964)., In the vicinity of the nutrient-rich Laguna Beach sewage outfall, California, Bandy et al. (1964c) found populations 5 times greater than elsewhere. These examples suggest that patterns of foraminiferal abundance point toward sources of organic input in an estuary. Number of Species, Diversity and Dispersion The relative number of species in a population, or species diversity, offers 6 useful means by which a population can be described. Recent studies (Gibson, 1966; Walton, 1964b) indicate the diversity is inversely proportional to the variability of the system. For example, the distribution of diversity in Mississippi Sound (Gibson, 1966) is relatively low (10 -'15 species) in areas-of high wave and current activity or where salinity, temperature and turbidity are variable, whereas it is relatively high (25 - 40 species) in more stable water of 'the inner shelf (Fig. 3). Thus, diversity distributions of foraminifera are a means by which different habitats and different populations may be compared in terms of environmental variability. Closely related to species diversity is another characteristic, "faunal dominance," or the percentage occurrence of the most common species in a population (Walton, 1964b). Faunal dominance is directly proportional to environmental variability and inversely proportional to diversity. Varying from 90 percent in marshes to 20 percent on the continental shelf, it serves as a guide for examining broad trends in which rare species of nonindigenous species are present. Like other estuarine populations, foraminifera are dispersed spatially in different patterns either random, uniform or clumped, according to their habit. The degree of clumping is a significant characteristic of a population but only a few studies have been made (Schafer, 1968b;'Ellison, 1969; Lynts, 1966). In a study of spatial distributions in one square foot of Rehoboth Bay, Delaware, Buzas (1968b) observed an increase in aggregation with an increase in density random distributions were due to individuals settling out of water, whereas the abundant species.were superimposed upon the random distribution as an aggregate due to asexual reproduction which produces a group of young about one parent. Shell Characteristics and Composition Foraminifera are often grouped according to the mode of their Shell con- struction., These constructions appear to have environmental significance. 1. Arenaceous or agglutinate species build their tests of sand grains, mica'flakes or other particles which they can cement together by carbonate or chitinous secretions. They occur in freshened or brackish water off river mouths and in partly confined estuaries where stagnant conditions often develop. 89-100. T-50. 96-140' 6 0 Q@ 'LIVING POPULATIONS NAUTICAL MILES SPECIMENS/ SAMPLE SAN 'ANTONIO BAY 100 or less 25-1 9 29* L9f X 100 - 500 0 1 2 3 4 30' 30, 500 - 1000 x '302 NAUTICAL MILE'S 1000 or more N variable 4 to 700 71 x55 X91 280 X21 280 -io HI H 111 20' 29* 20' 20' 68X X206 58x x23 34x X216 A- X 183 95X x 104 29* 29- TO TO 224 X 96-150' 9 89-110. 89TO@- 00 Fig. 2. Standing crops of benthonic foraminifera in southeast Mississippi delta (left), from Lankford (1959) arid in San Antonio Bay, Texas (right), from Phleger (1-964), 0 U Poe G U L F 4 -M-E-X I C DIVERSITY DISTRIBUTIONS, MISSISSIPPI SOUND AREA, VALUES CALCULATED FROM PHLEGER, 1954. PARKER, i954 TREADWELL. 1955. Fig. Diversity distributions in Mississippi Sound, from Gibson (1966). 0 91 2. Calcareous species construct their tests of calcium carbonate secreted by the animal or precipitated from water. These are either p@orcelaneous (imperforate) or hyaline (perforate) * Calcareous species mainly inhabit more marine water. Near sources of freshwater tests are commonly small and thin; some species (e.g. Strbblus beccarii vars.) have chitinous inner linings. When foraminifera grow'in,estuarine situations with high seasonal stress or pollution they often develop irregularly arranged chambers with contorted shapes at the apertural end. Abnormal specimens are reported by Arnal (1955) in Playa del Ray Lagoon, California, a confined and stagnant body of water, and by Stewart (1958) in closed San Miguel Lagoon, Baja California. They were found by Lidz (1965) around piers of Nantucket harbor. In landlocked Salton Sea, Arnal (1961) observed relatively high frequencies of abnormal specimens near the mouths of small streams. In laboratory cultures of Bradshaw (1955, 1957), chambers of Streblus beccarii became more irregular with,an increase of temperature, a feature probably brought about by scarcity of food with increased metabolism of high temperatures. Planktonic Forms Although most foraminifera of estuaries inhabit the sediment surface a few attach themselves to rocks or plants and others are derived from ocean water masses. 'Planktonic forms, characteristic of offshore w6ter masses, are often found together with nearshore benthonic forms where ocean water extends close to shore on an arid coast or in deep neutral embayments, e.g. San Pedro Bay, California (Bandy, 1964). When planktonic specimens are found in estuaries they may indicate occasional introduction of oceanic water. Faunal Composition Faunal composition when used together with other faunal characteristics provides a handle for comparing and classifying different estuaries. This is possible because estuarine foraminifera consist of characteristic species with dominant genera which have adapted in similar ways to similar conditions. Although the specific composition maydiffer or overlap somewhat from estuary to estuary, most groups are represented in many widely occurring estuaries from coast to coast. The change occurs mainly with distance seaward from fresh to marine water.. Thecamoebina fauna is characterized by small agglutinate forms that are close relatives of foraminifera but not classed as foraminifera. This group inhabits freshwater marshes, cypr .ess swamps, bayous, lakes and rivers. Two common genera are Difflugia and Centropyxis. They are recorded in the lower r T- Housatonic and Connecticut ivers Parker, 1952), in the Guadalupe River, Texas (Parker et al., 1953), and in the Mississippi Delta area (Walton, 1964b). A detailed st7dy of thecamoebina along river courses in Trinidad by Todd and 92 Bronnimann (1957), indicates that different species occur in diff erent river subsystems, or "zones." A Miliammina fauna inhabits slightly salty water at the beginning of marine influence. This fauna is arenaceous and often includes species of Amoastuta Trochammina and HaDlophragmoides, all of which also inhabit bordering intertidal marshes. In some areas this fauna often grades into, or is replaced by, a dominant Ammobaculites fauna. An Ammobaculites fauna is common to inner or central parts of estuaries having intermediate salinity. In middle latitude estuaries it often makes up the main component of maximum populations off river mouths; diversity is relatively low. Lowman (1949) noted that shoal brackish waters which are occasiona13,y stagnant are more prone to development of an arenaceous fauna than well-aerated waters. Seaviard in more marine water of lower estuarine reaches, the Annobaculites fauna is.replaced by a calcareous Elphidium. fauna. The change from arenaceous to calcareous character is a marked feature of estuarine faunas. It may reflect the availability of calcium carbonate used for test construction (Greiner, 1968), a feature which in turn depends on salinity, temperature, pH and the supply of river-borne calcium. The Elphidium fauna is a more diverse group than the Ammobaculites fauna. It includes many species of Elphidium. plus Streblus and miliolids. It inhabits lower estuarine reaches bathed by relatively salty water and penetrates landward in channels or through wide inlets which allow invasion of ocean water. A Miliolid fauna is intermittently present in estuary entrances, adjacent barrier beaches and nearshore bottoms where turbulence is great. Specimens are robust, thick-shelled typically porcelaneous and relatively diverse. Added to the fauna are representatives from the Elphidium. and Streblus faunas. The Streblus fauna is a relatively widespread transitional fauna extending offshore to about the 60-foot depth. It often intergrades or overlaps the E12hid fauna around estuary entrances and has a relatively high diversity. Mixed faunas occur in migrating subsystems, around river and inlet entrances wherF-currents are active in transporting tests and sediment. For example, thecamoebinids are often swept into the Miliahmina or Ammobaculites --- lyr fauna by river floods or freshets. Similarly marsh specimens may contaminate" different estuarine faunas when eroded from. bordering banks by wave action. Mixifig can be recognized by the sparseness of living representatives, departures in the distribution of living dead faunal boundaries and local increases of diversity. HORIZONTAL PATTERNS The most distinctive patterns of estuarine foraminifera are those which occur with distance seaward. In temperate estuaries this pattern corresponds to a change from fresh to marine water but in estuaries of arid coasts the change is from hypersaline to normal marine., The broad horizontal patterns in temperate estuaries consist of: 93 1. A seaward change in faunal composition from dominately thecamoebinids in freshwater to arenaceous Miliammina or Ammobaculites in brackish inner reaches, and farther seaward to calcareous Elphidium miliolids and Streblus (e. g. Fig. 4). 2. A seaward increase in the number of species as more marine and stable conditions are approached, e.g. from less than 10 to more than 25 species. There is a decrease in faunal dominance from about 90 to 30 percent (based on percent occurrence of the most dominant species). 3. Large populations occur near the effluence of rivers or inner reaches of estuaries, i.e. sites where nutrients are introduced into marine water and where salinity stress is high. Numbers diminish both land- ward as well as seaward, away from the loci of peak abundance. 4. Arenaceous forms, or calcareous forms-with chitinous inner linings, dominant near river and inner estuarine reaches, in contrast to calcareous forms in lower reaches. Calcareous tests become smaller and thinner near sources of fresh water (Walton, 1964b). 5. Marsh forms contaminate inner reaches where marshes border an estuary. A few planktonic specimens may occur where ocean water approaches mouths of deep estuaries or invades embayments. These broad patterns develop different dimensions according to the estuarine configuration, the degree of river dilution and mixing, and the magnitude of environmental stress. For example, Walton (1964a) observed that the Elphidium Streblus fauna, which was so widespread throughout the relatively saline water of Tampa Bay, could not withstand the extreme dilution of inner Mobile Bay. In the Rappahannock River, Virginia, the thecamoebinid-Ammobaculites-Elphidium faunas extend through a broad gradient of salinity for a distance of 50 miles (Nichols and Ellison, 1967) whereas in the Yaquina estuary, Oregon, essentially the same faunas are telescoped into a narrow salinity gradient less than 10 miles long (Manske, 1968). In San Antonio Bay the bay facies dominated by Elphidium spreads out over a broaa area of the lower bay (Phleger, 1960), where- as in the Rappahannock estuary a similar fauna penetrates landward in a narrow zone of the estuary channel (Nichols and Ellison, 1967), (Fig. 5). In the James Estuary, Virginia, patterns of the Ammobaculites-El-phidium faunal boundary are skewed diagonally across the estuary-in a way that@suggests a response to Coriolis force manifest in the estuarine circulation and/or salinity distri- bution,(Fig. 6). Horizontal patterns may be expected to shift and alternate with changes in energy source and magnitude of stress. The Yaquina estuary, Oregon, alter- nates from well-mixed to partly-mixed with a change from high river inflow in winter and spring to low runoff and nearshore upwel-ling in summer. Foraminifera patterns recorded by Manske (1968) shift either upstream or downstream in re- sponse to these changes (Fig. 7). In"the Rappahannock Estuary, Virginia, which has less intense seasonal stress and a wider salinity gradient than the Yaquina, faunal patterns also shift along the estuary with changes of salinity and river inflow (Ellison and Nichols, 1970), (Fig. 8). Both estuaries have similar dominant faunas but in the Yaquina there are more than 30 species whereas in the Rappahannock there are 211. "1W 2W V SSW W e 30, 'W SSW So 3 S L ft At 4 4 GIAMORT MISS to S PP, IS, so aculit T IS. e 'el., tf, )VA. R 10'1'o Elphidium spp. .!/Ph turn. CO 'I70blacul tA Ad Gew 50, 20@ IW 46 3W Fig. 4. Seaward change of principal foraminiferal faunas on the Gulf coast,. Louisia .na to Florida (Modified from Waltont 1964b), J, NO SAN ANrONIO BAY RAPPAHANIV ESTUAR Fig. 5. Comparison of faunal patterns in a well-mixed shallow,ba,", San Antonio Bay, Texas, and a partly stratified river estuary., Rappahannock Estuary, Virginia, from Nichols and Ellison (1967). 95 76-@30' JAMES' ESTUARY 0 21 4 6 8 Mulberry KILUMETERS 0 1 2 3 4 5 Poini NAUTICAL MILES 5m '.Rocklanding Shoal ........... N .............. . ......... ... M ...... ........... 14 37c h1ph id ,/ b707 11% foQ110 NEWPORT NEWS a7l % 6705 FORAMINIFERAL, FACIES 18 AND SALINITY --14 BOTTOM ISOHALINE, '/,a!* BOUNDARY BASED ON DEPTH -J@ TOTAL PERCENTAGE L Fig. 6. Ammobaculites-Elphidium faunal boundary in the James Estuary, Virginia TF-romNichols and Norton, 1967)- 96 .U 20% Fig- 7. Distribution of principal foraminifera zones in Yaquina Bay, Oregon, upper, winter; lower, summer (Modified from Manske, 1968). F- 7** T > V 0 --n m > 0 Ch m cu > m W @xj r@ 1> 11 ril ch pd @3: (D P- 0 ct, P. 0 ::5 ct, P. cf- %,0 o r:r m cf- (D ...... . ..... P. ct, En " 7r 0 P. .:5 @-j ct I ct, Fl- P- (". CD t:s 0 CD t:s C-4 0 @-b 0 ct ct, cu z > rn cz C+ Jr.x C'U A > OD Z6 z PI C/) 98 VERTICAL PATTERNS Superimposed on the horizontal patterns there are smaller, less'striking patterns with depth channelward or with elevation across flats. Vertical patterns are most conspicuous in intertidal zones of flats and marsh backed by freshwater ponds. They may also occur in deep estuaries, fjords and open embayments that merge with the continental shelf. Less striking are those that develop in shallow confined estuaries nearly cut off from the sea. For example, in Sabine Lake, Texas-Louisiana, shoals are inhabited by a Haplophragmoides Miliammina fauna whereas lower parts of the estuary floor are occupied by Ammobaculites (Fig. 9), (Kane, 1967). On shoals of Laguna Madre, great numbers of miliolids, up to 1640 living specimens per 10 ml, reflect high production on the lighted thin-grass shoals (Phleger, 1960c; and Odum and Wilson, 1962). Distributions of marsh foraminifera around Galveston Bay, Texas, (Phleger, 1960) display seven sub-zones that are partly related to plant zonation and other variables as tidal flooding, salinity, etc.,, all of which vary more-or-less with elevation. In the deep Juan de Fuca and Georgia Straits of the Pacific north- west, Cockbain (1963) differentiated 9 sub-zones, some of which varied with depth or related factors. Interestingly, faunas that inhabit freshened inner reaches of an estuary, also occupy shoals of seaward reaches which are influenced by partly freshened water. This is illustrated in foraminiferal distributions of Yaquina Bay, Oregon (Manske, 1968), (Fig. 7). CHARACTERISTICS OF FORAMINIFERA IN DIFFERENT SYSTEMS- High Energy Beaches Specimens are large, robust and thick shelled. Small, fragile forms do not survive the intense turbulence and sorting action of wave action. Large Miliolidae, Elphidium and Streblus dominate faunas on the Gulf coast (Phleger, 1960c). On the Pacific coast Cooper (1961) found abundant hyaline specimens and relatively few species (averaging 15). On southern California beaches,, Bandy (1963) reports abundant broken, damaged and worn specimens. Lankford (1962) delineated two faunal provinces in beach and nearshore areas along the Pacific coast with a boundary at Point Conception, California, Miliolids and Elphidium were limited to the southern California province. On the Atlantic coast at Martha's Vineyard, Todd and Low (1961) recorded variable numbers of Miliolids, species of Elphidium Streblus and Rosaline. Presumably they were largely derived from seaward of the low tide line. High Velocity Channels Under conditions of strong currents, foraminifera are sparse and limited to minute or attached species. Todd and Low (1961) report flattened forms of the genera Rosalina and Cibicides in current washed inlets of Martha's Vineyard, Massachusetts. In tidal channels of Hadley Harbor, Massachusetts, known as 11gutters," populations vary in abundance and species diversity (Buzas, 1968a). Channels leading into lagoons on the southern California coast contain beach species mixed with lagoon species (Bandy, 1963)- Bottom sediments HAPLOPHRAGMOIDES 99 MILIAMMINA EDAMMOBACULITES. SP. STREBLUS - ELPHIDIUM MILIOLIDAE N 0 2 A L Jz= MILES 26 Fig. 9. Foraminiferal patterns in Sabine Lake, Texas-Louisiana, from Kane (1907 3 117-49' 4 117-46' 33' 33' JJ7-49' 0 '34*7 ';@ - 34' 33 KILOMETERS A OUTFALL KILOMETERS LAGUNA A OUT FALL BEACH LAGUNA 0 BEACH 00 32 N 32' 32-,- -32' 20 3(Y too 30, 30'_ A. TOTAL FORAM INI FERA /GRAM LIVE FORAMINIFERA /GRAM 117 49'-- 117 46' 117'49'@ IM46' 33 1 lr49? I lr46' 34!, _T T .33, 3 II7'4V 1171'4V 33* 34' 0 1 2 K ILOmE TERS KILOM ETERS A OUTFALL A OUTFALL LAGUNA LAGUNA 0 BEACH e) BEACH 0. 0.01 2 10 5 30'" 30! 130' D. LIVE BENTHIC SPECIES - C. LIVE /DEAD RATIO L 117-49' 111*46' 4o IIT'49 ""46' Fig. 10. Foraminiferal patterns around the Laguna Beach sewage outfall, from Bandy et. al. (1964c). 100 Sedimentary Deltas Foraminiferal faunas are best illustrated by the studies of Lankford (1959, 1967a) on the southeast Mississippi delta (Fig. 2). The "fluvial marine" fauna of passes consists of abundant Palmerinella gardenislandensis, an arenaceous form. Seaward of the passes where river and gulf waters actively mix and where sedimentation is fast, the fauna is characterized by very high living populations dominated by 4 species of the genera Bolivina Buliminella_, Epistominella and Nonionella. A very different faunal composition is recorded by Phleger (1960a) off the Guadalupe River delta in inner San Antonio Bay, where there are abundant arenaceous Ammotium salsum and Palmerinella eardenislandensis plus species of calcareous Elphidium and Streblus. Because of rapid sedimentation, dead populations are "diluted" and the ratio of living to dead tests is high. Faunas of the two areas are similar in having large standing crops composed of only a few species. Hypersaline Lagoons Faunas described from Laguna Madre, Texas, by Phleger (1960c) are dominated by Miliolidae which inhabit sand substrates commonly covered with thin grass. In deeper areas of silt and clay, the fauna is dominated by species of Elphidium and Streblus; miliolids are less abundant. In turbid, poorly vegetated Baffin Ta-Y, Texas, the fauna is impoverished and the number of species few (less than 7). Blue-Green Algal Mat Faunas on 'matted" barrier flats of Laguna Madre are dominantly miliolids that occur in relatively large percentages. On an algal covered barrier flat of St. Joseph's Island, Texas, Phleger (1966b) recorded abundant miliolids plus species of Streblus, Elphidium and the arenaceous genus Ammoti . Species average about 15, a number slightly higher than in most surrounding marshes. Mangroves In the marsh-mangrove bay areas of Whitewater Bay and Ten Thousand Islands, Florida, Phleger (1966a) found dominantly calcareous species similar to those in lagoons of south Texas plus a few arenaceous '!marsh" species. Populations are relatively large and fairly diverse, embracing about 20 species. Tropical Meadows The foraminiferal fauna of Florida Bay is characterized by abundant calcareous miliolids (Lynts, 1962). They tend to increase in abundance seaward toward more salty marine water, whereas Streblus beccarii and Elphidium galvestonense the other principal components of the fauna, tend to decrease seaward away from freshened water near the mainland. Populations are very diverse, ranging up to 57 species for the whole area, and they also vary widely in abundance (Moore, 1957). 101 Blue Water Coasts Blue waters bathing the southeast coast of Florida in depths of 0-40 feet, hold a more diverse fauna than in Florida Bay, consisting mainly of Peneroplidae and Miliolidae (Moore, 1957). Populations are variable owing in part to sorting by currents and waves. Tide Pools Foraminifera reported from algal-ri-mmed tide pools from Oregon and California by Cooper (1961) vary widely in abundance and in number of species, from 12 to 46. With distance from north to south the over-all number of species increase. Most forms are hyaline (those with perforate calcareous tests) but there are small percentages of arenaceous, and porcellaneous forms, in addition to a few distorted forms of Miliodidae and planktonic fossils. The fauna is believed to be indigenous to nearshore areas and swept into the pools by waves and currents. Oyster Reefs On oyster grounds of the inner James and Rappahannock estuaries, Virginia, foraminifera reach maximal numbers consisting of 1 to 3 arenaceous species, mainly Ammobaculites. It is not known if these faunal features are part of the oyster reef economy or part of the estuarine-wide economy. No'cagual relationship between foraminifera and oyster reefs has been reported even in the fairly detailed studies of oyster-rich Mobile Bay., San Antonio Bay (Phleger, 1960), and Matagorda Bay (Shenton, 1957; Lehman, 1957). Marshes Marsh faunas are very variable in ccmposition and abundance. They are typically arenaceous, law in diversity ( 5 - 8 species) and appear to have a very wide distribution (Phleger, 1960b). Characteristic genera include Ammoastutp., Trochanmina and Miliammina. Detailed studies have been made on the Texas coast by Phleger (1965, 1966b) on the Massachusetts coast by Phleger and Walton (1950) and by Todd and Law (1961) and on the southern California coast by Bandy (1963). They are often washed onto adjacent lagoon or estuary floors as "contaminants." Oligohaline Systems Foraminifera of the salinity "gradient" zone in the inner James and Rappahannock estuaries,-Virginia, consist of very large populations of 1 to 3 species, mainly arenaceous,forms dominated by one species, Ammobaculites. Populations averaging 225 specimens per 10 ml are larger than most medium- salinity plankton estuaries, but less than the very large populations off the Mississippi River'. The fauna is partly contaminated with a few "marsh" species derived from upstream. Medium-Salinity Plankton Estuary Foraminifera of this type system are exemplified by those in Long Island, N. Y., reported by Buzas (1965). The entire fauna consists of 23 species with larger numbers toward more marine areas to the east. Calcareous species 102 of Elphidium plus Buccella frigida and E yZerella advena, which constitute 90 percent of the total population, form three depth zones at depths of 36, 76 and 87 feet. Living populations average 177 per sample at depths of 30-60 feet and reach 335 per sample in shallow water 0 to 30 feet. Large-populations occurring in October and June correlate in a general way with the zooplankton and phytoplankton cycles as well as times of maximum temperature. Emerging Systems There are few comprehensive studies of foraminifera in new man-made systems except those of sewage outfalls on the southern California coast studied by Bandy, Ingle and Resig (1964a,b,c, and 1965a). Both benthic and planktonic species reflect nutrient enrichment by their great abundance near the outfalls and by a reduction in species number (Fig. 10). On the Kennebec River estuary, Maine, toxic paper mill pollution led to low abundance and few species (Schafer and Sen Gupta, 1969). In Nantucket Harborp Massachusetts., organic- rich muds exposed to sewage yielded an abundance of abnormal specimens (Lidz, 1965). On the other hand, an abundance of Florilus gratelou-pii and Fursenkoina pontoni is favored by sewage pollution in Mayaguer and Guayanilla Bays, Puerto Rico (Seiglie, 1968). McCrone and Shafer (1966) report Ammonia beccarii tolerates substantial pollution in the Hudson estuary. In a study of thermal pollution effectsChristensen and Ellison (1965) found high temperatures, up to 140C above normal, have only limited effect on Ammobaculites. Additional studies are needed to determine how foraminifera respond to different man-made stresses. PROBLEMS FOR FUTURE RESEARCH Knowledge of foraminifera at present is not fully adequate to attack the multitude of future problems arising from pollution and conservation of water resources. Certain areas of understanding are deficient and require attention. The following are priority studies, though not listed in numerical order by priority, within reach of investigation with present tools and which hold promise of solution. 1. -Although natural distributions of foraminifera, are known from many systems they do not cover all estuarine types. They can serve as "base-line" information for evaluating future man-made changes before such changes occur. Distributional studies are needed in: (1) Glacial and turbidity outwash fjords, (2) ice stressed inter- tidal zones., (3) high energy beaches of the east coast, (4) oscil- lating temperature channels, (5) tropical "meadows,," and (6) tropical plankton bays of Puerto Rico and Hawaii. 2. Emerging man-stressed systems have been little studied except for sewa e outfalls, in temperate neutral embayments and shore waters. 1 9 Basic distribution studies are needed to compare patterns in different stressed systems at varying scales and intensities of stress, from the tropics to the Arctic. It is of special interest to know haw foraminiferal populations respond to conditions in new systems as regards number of species, abundance, development of abnormalities, spatial variability, and diversity. How do distri- bution patterns shift in response to deepening, damming or diversion of an estuary? 103 3. To further our understanding of distributions in natural as well as man-stressed systems, more infoxmation is needed about.the system itself, especially time series that show extremes, durations and rates of change of temperature, salinity, pH, current, light, oxygen suspended concentrations and other parameters. This information can be obtained from existing continuous recording instruments, such as developed by Bradshaw (1968) and furtherused for analysing the ecology of other organisms as well. Automatic processing and computer analysis should facilitate handling large amounts of data and analyses of Yarious environmental variables as a group. 4. To refine our evaluation of distributional features we need to know haw foraminiferal tests 'behave under turbulent conditions; and to what degree tests are passively transported and dispersed by tidal currents. Detailed analysis of foraminifera and of suspended sediment, supplemented by simulated conditions in laboratory flumes, will aid in this problem. Eventually, foraminifera may be of use in measuring the degree to which sediments are dispersed by turbulence and mixed by other organisms. They are potentially useful as a tracer of dredge spoil. 5. Like other marine organisms, foraminifera are capable of concen- trating trace elements including those of man-made wastes. inasmuch as the trace composition is little known, analyses need to be made to determine what elements are concentrated by different species and how they may affect the size and survival of entire populations. 6. Of special import is the need to relate the production of foraminifera to total organic production. If a relationship can be developed, foraninifera could be used as an index for recognizing productive estuaries and for comparing organic production rates with time or in different systems. 104 Part III-A ECOLOGICAL SYSTEMS BY STATE B. J. Copeland H. T. Odum Marine Science Institute University of North Carolina The University of Texas Chapel Hill Port Aransas, Texas 78373 North Carolina 27514 In the same sense that maps of geological formations, soils, forests, and agricultural use are the basis for management of systems of man and nature on land, detailed maps of the ecological systems of the coastal waters are needed. In some states there are already detailed maps showing shellfish locations, bacterial pollution, salinities, and other related properties, btt not maps of the whole operating ecological systems as defined in Part I. Most states have the personnel to do this mapping in a relatively short time because of knowledge accumulated already in management and scientific studies of the bays. When accomplished, the detailed maps may become the basis for manage- ment of the coastal systems of America, especially as our knowledge of the types develops further. For consideration of the national estuarine resource, some small scale maps that locate a few examples of each type of ecosystem in each state are given to help readers visualize the system types in the ecology of these states. In this chapter, using the maps, we list examples of ecosystem types obtained in interviews in each state. A number of state authorities have indicated their disappointment that these small maps show so little of the detail already known locally, thus underscoring our recommendations that the detailed and documented resource maps be done by ecosystem type as a national project with state-federal collaboration. This volume, however, is written to lead non-scientists into the estuarine literature. The small maps are presented in the belief that basic concepts must be first introduced in simplified form. We seek to show,readers new to estuarine science some examples of locations of ecological systems, to show readers familiar with one state the charac- teristics of' another, and to show the kind of mapping approach that might be followed in doing detailed large maps of the same areas. The maps also show locations of the estuaries discussed in the chapters that follow. Lest there be misuse of these introductions we pass on a caution from one of our correspondents quoted as follows: what needs emphasis is that we have almost none of the hard, detailed information which is needed to intelligently manage most of our shore areas. Written material like this is likely to give would-be managers the illusion that they know a whole lot, and can now proceed with safely predictable results. It seems to me this could lead to great damage. What these managers really need is a brochure setting out the complexity of the problems to be faced, and pointing out the necessity of making detailed local studies of*each particular situation before making drastic changes therein." 105 Within each geographical area there may be several 'systems and subsystems in juxtaposition with each other. A large bay, for example, may be surrounded by marshes, tidal.pools and mudflats-and contain in it an oligohaline system, medium salinity linkton system, o p yster reefs, grass bottoms, and migrating subsystems. Thus, the classification of one large bay may be difficult and complex because of the-neicessity of all these systems and subsystems interacting together,to provide the productivity characteristic of that bay. You may find, therefore, many classification designations within one small area$ such ad Chesapeake Bay, Pamlico Sound, Galveston Bay, or San Francisco Bay, to name a few. Maps are alphabetically arranged by state except for Alabama in Fig. 3; Connecticut in Fig..9i, Delaware in Fig. 8; Mississippi in Fig. 6; New Hampshire in Fig. 7; Rhode Island in Fig. 9; and Virginia in Fig. 8. We acknowledge the suggestions of many in the states. Figure 18 (Us S, Federal Water Pollution Control Administration, 1967 1) is a more detailed mapping of only one ecological system (sea food waste) in the estuaries of a single state. It illustrates the difficulty, but also the potential usefulness, of such mapping. E Al@ A fit kftf'- 3@.'o C T ''J@4 p?", , C A11.1 &f- Sri- N'.iw F, , 3"' -1 D. D 0: @'. ke 4,,, U@d,r- cc ft-kf- 17 L 4.5 kA 170 CP o. 04A /aa* 14-t /26, CallfWnt, 107 A2 - #,@4 bed-4es A C1 - rtdc fools C, - &'rot hla@jv -4r ca- Iieffid.1 ra@ks Cq - MR-Aes cr- ny'-t-r ree4s C4 - Worm @j cf.. 044S C7_ 6nass kD4+0-1 Cf- 0/"r.A.6,e sy.:Oe-3 Cj_ Mediu- SI),,A7 pla"k+D" syj@e_ C/1- kelp beds CI, Ne,frAl emb^y-e@-l E F3_ de3 Z 1-7 Sp red E S- Empound rvlehl E&@ Theryvu%l PO'lm+'O" E7- P-1p mA Ell - Petroleum shores E 13 -So"'A'. E)S-- Jwrac@e-icajq E-17- Mu.1j;ple s+ress C C E, '5"M FIAOCI CAL I FD@ N I A JDS@ 37' & C'.. M- 'Y'y q C, Dc@ IV@ Los AAIGELES 5an E, ly cal4wr6o, 0. Mexico F Fig 2. CalifOrnia 108 Suwannee fiver 31 W4 c r C@ S54L /6 M-T-es Bz C,,-/ A-, 63 FL OR I D.A Lu C-t C,- A-r C4 c@7 Cj@ - W-6. -67 M,b;L Nk A 6- 31 At Olt P- 51'7 Fig. 3. Florida and Alabama 109 162" 93 33 33 C-3eacL A M-a r S (all est"OL"Ies) C 4- 5i-e r lee e IA) o r ryN Cla, -a ro l,'/j 'h 1; 0 LA ol@@O c I? - AW, S,4 @f,5 @c "n F 177 1 fF 3- Pe 5 C e-S 6- 7- Pa pe r MI'll Yee 9,!; j A SS& CIA) xv (w Ileplitha- SO-L"d 31 st-Ancire-0 31 N. r MCWL v-: Ja 03 Fig. 4. Georgia HA A A/ sz- A A/Z)g -k ISM A;t kau 6-1 64 E-I v em C.Zr A, A2. s- A3 m A4 Hypersafine- L4?Don-s Ned 9 1.. Ha. wa ii Mangroves E 1, Tlerr"lj WAC, 82- rDral Rce@s ET Paper Mill a,05h ,83 TropiUll MeOCLIDLO-s Eg StAgar 'Sane uAsM 3 q Tf-op,c@ A"shfe P/4-kion E it pe@roleum @540re-s @uc Wafer Cow7h E13 Salina F-Is- )OetrocAcynicab FP7 MIAIf;,PIr- 0-1 'S Y S'rEffi S Az H* Se"ex A S' Sectimeo+wy bel+as cc C@S+Of ReeP, M I.SS is-S C4, Worm and Clam Fla+5 c F DljqOlqA);.e Sy.+..S C1 Medium Salif,tj PI4nk+.,i ES+,.ry C 12 AfeLfrxl Eftbaj-e.f Wa4fe "V Ez 3CCLA04 tdo-Stes ,67 Pbee,- MVI 'er suraecdtric &J4tsfe -,C-13 Fe'@Che";j"b 45-0. Inrl-LIA E17 r.4vWFIC 10 L o- u siA nq fit Pearl R, ver 4.. 'P. rcharrx*@" 6-4 S c? CIO yPI-I F 43 C&I 90 5 q 13 1 Fige 6, Iouisians. and MississipPi @ 5 y 5 -rE' A S cl. m.7 ar@ @'+.S bi Croix MAWE 41 %n*_@ 4e- NEW HAMPSHIRE MAINE sanfc>r, Portsmvt 610 WeS io Ile reel Ile- C, ga.h.. as Solis MA55. t uAp*" Sol py OF 0 9 YSI'4"S,,b FUND 2. 4* -@6t qXLE-C -/A S :.6.1t0 At Rockj Sea Fron@s Porto AZ "', Encrqj Beaclics Ag nil@ veloci@ Td.,e@ P001S C IslanA3 Cs jm+erfidj ROCJ-S k biorm Qlot clav" Flats @a Wine S@ems X. r_,& 01 S1 Es+tAary c qIA i 10 3 1 . tZ Plank 0 , iuvA A Ini I cl, )@elp 8eds t Covstol Pfa.,k-Fon C E5,WGle Wclsfi _F'7 Mill W&sf& F1 4fZ Sirest f 11 Mulf0c L 44 Fj 43 113 MARYLAND Wti;-c r pckfAF5c 0 51 '4'z -ll;5,k 77 We Poo c 4- Mars F C C. Clan, Y C7 'f; vs, 0 Ine S , b ct 5- say C@ 4 14 It Polkfio- fo/&uM 56rC5 es Pe f,,ochermica#5 fe amoc 4' ';' 3Y e Oce c+ @ @F 37 v L '71 '72- fU Fig. 8. Maryland, Delaware, and Virginia Afl- AwAl A I- e F=-i Aa- 4, L'Neril a A .v.. l4e T ;@:,k. T ll@.. 14MAIM CS C4- Aws 4!S-7 075i'l, Aterr C 4 -W-- i Ch- C 7 - --.)I r ... i Allal i6h'.- Massach its e-tr C 0'14 A./- 1.0,- @S? F - 0773@i;.j 5.6.7.4- KI -S.-Y. W.O. E70 -P",@,. c;d@ Tr- C. F4- 4=14 ol Fit- -r,... PuL.1 S" 0 Ell- M./I;?/, st-gs C+ 'k Sp.// bury Ci- Mal" 1 13" b. W 4V 43- 75 Oat -Rhod e Co nmeCT AND IL A. C- C-F 104 t.,JJ Fj 4'7 3.15 I 7t/ 41 New Ye-r5c Aa- #;Ik MI,1-61L cr - 0 Yj Fl, C -I- C. r3-Ha- -@,4-- e I 'we. YS Wi fClv. 6C..4 et- g5@ba,/@,ot F /y7;' as @c 000, P.. Sp.j/ L ot, ZF( . P. //. @ ".,j 'a 40- 40"' co. C;tv t Oil v. ry PC 7 0 eel(4 r..e 31- At-Y Fig. 10. New Jersey 77J. F6-1 W`vK C4- Marsk e,,- e7- es- lq- plwkl@ conn. Fl- 0'a-sl ZZ- P,@-(-;../s In 5"7- ONG, 15LPMD 'ittis 0.4", 0 5 L jc@ N. "Y. o t4 Gr moo a-y 3-Y lea, 4f lz kN ,Z- K n7 Vi 36 Nort a r 1,in a x-0 cr- Fid C6 - '0 - ? "4 ,. ).I;.. Sit cl /Y7. .4." F W.d@ J.j r 64- Fig. 12. North Carolim -7 T-- U8 i L3 c c W 416 Joe C'? 4+- A ON C', 0!S @;/ST E MS A I Rr-1: SCOL FrOn+S A 2 H I.I @IEmerjj Beae-kes He /13 H'ik Vol r I Tde P0.15 c 2 )3irt lslcknJ3 C 3 ROr-k' 431 c (),&fer efeePs C6, C WDf"A "fj Alial 8000@1 Cl EclqrAss C2 E>11*10 Ci Med,6,, Plankhm 6Sfaarj C1, Kelp Beds - W, L OLS califernift IL16 F"g. 13. Qregon a Z)b 0 fo (b Lh rn (A U) rb W rh b (b t7 C-N to CI% O@a 6TT 120 42:- 14:@h averjj Re" r- 4- - fn a, r-s k cr- Oqs@e, ti- 0 1; To As c I -Med.," pla'A I., c o- A/e,,@irad Omb.711WAIi pe S4; -: de s E 4. -D,ed,);ol Sim:1 4ff S- -rInfc..)j "M-L 0-7- Pape- M,'11 Waskes. @/I- pe-t"I'mm Shore i& 3f @jff South Caro ina 4.0A @@D 4*jf b,,&f 50A "I 33 33- ST H lc@, bee Fig. 15- South Carolina W, & 7e 4e 121 TEX A 5 6), 3ysrcms A,, 31 H7, ""n 4 . ', A4 A7 83 [email protected] W.d- C4 M-k@, C, 0@,f, R@,F, @ W- -d cl., Fl.t@ C, M,d- C,@ W-fc' 5j@A-d Wa5t-- J FS- C7 RWp-ilf EIV B"6. P./l.f'o- Ew wa,k, F Fig. 16. Texas 122 -c -av a -a V&jc#(4ver am jsl'@ c1l -S@ 40 CANA-M 3 H vv Cot .Jc 0 -44 49 dooz) Everci-t C-ANAL cl Wp min ;.%&I kcre 11 SEATT L E 7 10 3 'TA com,9 cq 4T NZF "all A7- I E? LOW& WASH I N &TON Ai R-kj 5'. A@ Pll@ E-11 8-@- AH-,h ve-t@ Oak- 00@ CTd,, Mr c8- c Cafe E7 c' 0 @t-f'eh C4 W@- -d Cl- Ft.+, D C? E@lj'- -4 &Ith,l Al?-' 6.4- C, S4."e- C, M@d- S.1-ti Pl-kt- Es+--l C,. Sh@jj-Lj .d [email protected],d E@f-v C ' K P@:d;@b.j_f c:@ N@2+ rmiq'.f'@j ri 5-1@ W.@ E7 pm'Z'll W.Ae 44 E'@ p"" E'@' P4 li-+- 040, 4 E 7M. @ipl. Vl- Om%*#J Fig. 17. Washing-ton Fig* 18* Map of Alaska, showing sea food waste ecosystems only. (U. S. F.W.P.C.A. 19671) 2 2 uv 4 1/14 7 14 3 WESTERN 4 3/ 2 3 1 2 No-of Operators-44 -_10 2 T6,000,000 4 Approx. Ibs. of Waste I i;i;LL 22 1 2i 3 - 2 rc' 2 3 2 3 .3 CENTRAL SOUTHEASTERN No of Operajor-. - 104 No. of -operators -87 too Approx. Ibs. of Waste,- 100,000,000 Approx. Ibs. ot Viaste-55,000,:000 124 Part III-B COASTAL ECOSYSTEMS OF ALASKA C. P. McRoy and J. J. Goering Institute of Marine Science University of Alaska College, Alaska 99735 INTRODUCTION Alaska lives on its coast, a coast that extends from the rain forests of Southeast Alaska to,the arctic tundra. This is indeed a diverse and complex system. The gradation from temperate to arctic includes all types of coastal systems found in the lower states with the exception of the tropical systems and the systems stressed by complex pollution effluents. Ala*ska has only about 300,000'people. This small population, although concentrated on the coast, has a very limited influence on the natural systems of the 0',600 miles of coastline. Nonetheless, today Alaska is experiencin m g rapid econo ic growth which is larely a result of development of the natural resources of the coast. In the last year a very large oil deposit was revealed on the arctic slope near PrudhoeBay,and this once remote coast now has more flights daily than most cities in the state; speculation exists that the development of the wealth of the arctic slope will utilize icebreaking super-tankers. iRegardless of the type of develop- ment that occurs on the arctic coast, this remote area will change rapidly and much more knowledge of the coastal systems will be needed than presently exists. The arctic coast systems of the United States.are unique to Alaska. This report on the.coastal systems of Alaska concentrates on the systems found only in Alaska. In addition to the arctic coast (ice stressed coast), these include sea ice And under ice plankton (systems associated with the ice@covered open sea), glacial fiords (systems associated with fiords that have icebergs), and turbid outwash fiords (systems associated with fiords receiving turbid outflow from glaciers). This report is the result of the cooperative efforts of many people ,in the Institute of Marine Science, University of Alaska. The advice, criticisms, and'discussions of Dr. Donald W. Hood are most gratefully appreciated. The sections on fiords were principaily the results of the. efforts of Dr. David Burrell and Dr. Brian Matthews. The other sections were written by Dr. Peter McRoy, Dr. John Goering, and Dr. Mary Belle Allen with contributions from Mr. John Kelley, Dr. F. F. Wrig@t, and Dr. C. M. Hoskin. We are grateful for the technical assistance of Mrs. Laura McManus and Mrs. Rose Marie Nauman. 125 TYPES OF COASTAL ECOSYSTEMS IN ALASKA The complex coast of Alaska covers a broad geographical range in latitude and longitude and includes ecosystems that grade from temperate into extreme arctic. Most systems are natural. The problems of emerging new systems associated with man are limited to the few major population centers of the coast. The geographical distribution of the systems in Alaska follows (Fig. 1, Table 1). The diversity of the Alaska coast is reflected in this list. It includes every type found in the lower states with the exception of the tropical systems and a few of the more destructive pollution systems. As a further index of the diversity of the Alaskan coast we have calculated the miles of tidal shoreline in each region. The general coastline of Alaska is 6,640 miles long, which is 54% of the total (12,383 miles) general coastline of the United States (Pederson, 1965). The tidal shoreline, which includes islands inlets, and all shoreline to the head of tidewater, is much longer and reflects the,,intrica'cy of coastal Alaska. This distance is estimated to be 47,300 miles in Alaska and 88,633 miles in the United States. This tidal shoreline.in Alaska is greatest in the South- east region (63%), where the coast is a labyrinth of fiords, islands, bays, and rocks, and is minimal in the Arctic (2%), where the coast is a series of lagoons and barrier beaches. Another indication of the dominance of Alaska is provided by the corn- parison of the areas of the' continental shelves. There are three continental shelves adjacent to Alaska: the Gulf of Alaska, the Bering Sea, and the Chukchi and Beaufort (Arctic) Seas. These have areas in square miles of' 140,000, 320,000, and 370,000, respectively, for a total of 830,000. The total continental shelf area for the United States is 1,120,000 square miles. The continental shelf of Alaska, then, is 74% of the total shelf of the United States. NATURAL ARCTIC AND SUBARCTIC ECOSYSTEMS WITH ICE STRESS The ice stressed coastal systems of the United States are unique to Alaska. There are four of these systems: glacial fiords, turbid outwash fiords, sea ice and under ice plankton, and ice stress coasts. The first two occur in Southleast and Southcentral Alaska and the last two are Arctic (Fig. 1; Table 1). RESEARCH NEEDS No other state has coastal systems which are not already influenced to some extent by man. Alaska is unique in this respect and perhaps the, most urgently needed study involves collection of background data perti- nent to understanding the natural dynamics of Alaskan coastal systems. Probably some of the systems thought to be natural have already been stressed by man's'activity (e.g. global distribution of pesticides, etc.). 1720 1560 1400 660 -@LjT@AUFORr' Permanent Sea Ice BARROW SEA CHUKCHI 6 SEA 660 Sl&'Ef?IA ALASKA G ..KOTZ.EBUE eFAIRBANKS NOME 5 5 0 8 ANCHORAGE JUNEAU 'Seas 3 -,onal Se ;k -;z!ce 0 @58 BERING KETCHIKAN SEA L F 0 F COLD BAY A L A S K A IJ lop (@ 500 % 1720 1560 1400 Fig. Map of Alaska. Numerals refer to regions described in Table 1. 127 TABLE 1. COASTAL ECOSYSTEMS IN ALASKA WITH EXAMPLE LOCATIONS (LISTED IN APPROXIMATE ORDER OF IMPORTANCE) Types Found Example Location Region 1. Southeast Alaska Estimated miles of tidal shoreline 30,000 = 63% of Alaska Number of types = 21 Glacial Fiords Glacier Bay Turbidity Fiords Glacier Bay Rocky Sea Fronts Sitka High Velocity Channels Peril Strait Medium Salinity Plankton Estuary Auke Bay Neutral Embayment and Shore Waters Sea Otter Sound Sheltered and Stratified Estuary Port Frederick Oligohaline System Stikine River Sedimentary Delta Stikine River Intertidal Rocks Pleasant Island Tide Fools Pleasant,Island Worm and Clam Flats Icy Strait Kelp Beds Icy Strait Migrating Subsystem (salmon) Little Port Walter Eelgrass and Benthic Algae Klawak Bird and Mammal Rocks Forrester Island Marshes Mendenhall Flats Sewage Wastes Juneau Paper Mill Wastes Silver Bay Seafood Wastes Petersburg Pilings Ketchikan Region 2. Pacific Coast, Cape Spencer to Cape Elizabeth Estimated miles of tidal shoreline 6,500 = 14% of Alaska Number of types = 22 High Energy Beaches Cape Suckling Rocky Sea Fronts Granite Cape High Velocity Channels Bainbridge Passage Glacial Fiords Unakwik Inlet Turbidity Fiords Columbia Clacier Medium Salinity Plankton.Estuary Valdez Arm Neutral Embayment and Shore Waters Montague Strait Sheltered and Stratified Estuary College Fiord Oligohaline System Copper River Sedimentary Delta Copper River Intertidal Rocks Montague Island 128 Tide Pools Montague Island Worm and Clam Flats Orca Inlet Eelgrass Redhead Lagoon Marshes Redhead Lagoon Kelp Beds Montague -Island Migrating Subsystem (salmon) Olsen Bay Bird and Mammal Rocks Montague Island Sewage Waste Cordova Seafood Waste Seward Multiple Stress (earthquake) Beach Montague Island Pilings Valdez Region 3. Cook Inlet Estimated miles of tidal shoreline 400 to 500 1% of Alaska Number of types = 9 High Velocity Channel Forelands Sedimentary Delta Knik Arm Oligohaline System Turnagain Arm Worm and Clam Flats Cook Inlet Migrating Subsystem (salmon) Kachemak Bay Sewage Anchorage Petroleum Shores Kalgin Island Pilings Anchorage Multiple Stress (ice, oil, tides) Cook Inlet Region 4. Kodiak Island, Alaska Peninsula, and Aleutian Islands Estimated miles of tidal shoreline 1500 x 5 = 7500 = 16% of Alaska Number of types = 18 Rocky Sea Fronts Aleutian Islands Bird and Mammal Rocks Amak Island High Energy Unimak Bite High Velocity Channel Unimak Pass Neutral Embayment and Shore Waters Cold Bay Medium Salinity Plankton Estuary Kitoi Bay Sheltered and Stratified Estuary Kodiak Island Migrating Subsystem (salmon) Cold Bay Worm and Clam Flats Cold Bay Kelp Beds Shumagin Islands Eelgrass Kinzarof Lagoon Marshes Kinzarof Lagoon Intertidal.Rocks Aleutian Islands Tide Pools Aleutian Islands Seafood Waste Kodiak Petroleum Shores Amchitka Pilings Kodiak Radioactive Stress Amchitka 129 Region 5. Bristol Bay to Bering Strait Estimated miles of tidal shoreline 1800 4% of Alaska Number of types = 14 High Energy Beaches Kudiakof Island Sedimentary Delta Yukon Kuskokwim Oligohaline-System Yukon Kuskokwim Migrating Subsystems (salmon,,birds) Bristol Bay' Eelgrass Izembek- Lagoon Medium Salinity Plankton Estuary Kvichak Bay Ice Stress Coast Norton Sound Under Ice Plankton N. Bering Sea Marshes Izembek Lagoon Worm and Clam Flats Izembek Lagoon Bird and Mammal Rocks Pribilof Islands Seafood Wastes Port Moller Sewage Nome Dredgings Norton Sound Region 6. Bering Strait to Canadian Border Estimated miles of tidal shoreline 1000 2% of Alaska Number of types = 13 Ice Stressed Beaches Elson Lagoon Sea Ice and Under Ice Plankton Arctic Ocean High Energy Beaches Pt. Barrow Multiple Stress Beaches (ice, light, Kasegaluk Lagoon salinity) Oligohaline System Kotzebue Sound Sedimentary Delta Colville River Bird and Mammal Rocks Cape Thompson Worm and Clam Flats Kotzebue Sound Sewage Kotzebue Marshes Selawik Lake Eelgrass Shishmaref Kelp Beds Wainwright Radioactive Stress Kotzebue Sound 130 However, some appear to be in their original state and must be studied as such so that implications of future stresses can be understood. Northern ice stressed systems are particularly vulnerable to man's activity and should therefore receive immediate attention. With the rapid development of the petroleum industry now in progress in arctic North America these systems will rapidly be receiving stresses caused by industry. More specifically the scientific community should address itself to collection of background data pertinent to knowing what the level of world-wide, regional, and,local contamination of coastal systems is at the present time. Suspicious chemicals represented by three major classes should receive attention: 1) insecticides, herbicides, unique drugs, detergents, or other organic artifacts of man uncommon to the environment; 2) naturally occurring heavy metals such as Pb, Hg, Cd, Os, Be, etc. on a worldwide basis, and elements essential to or involved in metabolism but toxic in high concentrations such as Cu, Zn, Sb, Cr, etc.,(the latter are important largely on a local basis); and 3) inorganic elements unnatural or highly increased by man,s activities and the whole suite of inorganic elements resulting from fission or induced radioactivity. Methods of detection of effects of contamination on biological communi- ties is perhaps the area of our greatest weakness and need. When does a contaminant become pollutant? How can subtle, yet damaging, changes in a resource be detected, identified to its extent, and sound judgment be made as to its consequences? Sophisticated methods need to be developed to assess the level of a contaminant or combination of contaminants which limit the metabolism of a specific organism in a community or communities as a whole. Such information would be a signal to potential eutrophication, species diversity, and ultimate damage. Closely connected with the above is a need for better knowledge of dispersion, both horizontal and vertical transport, and of flushing (ex- change) of est'uarine systems. The biggest problem here is the lack of techniques that can be used to adequately assess these parameters. Even the problem of current measurements, pertinent to the above, is not fully solved, although much progress is being made in this regard. Remote sensors which can be safely placed in estuaries and be depended upon to give reliable information are badly needed. Vertical transport is a basic parameter that needs measuring, yet no satisfactory method has been devised to cope with this problem. Developments in these areas are essential before an under- standing of the physics of estuaries can be realized. There is also a need for studies of the continental'shelf. The deep oceans are fairly well understood or at least methods for their study have been developed. This is not true of the important continental shelf. 131 Transport of water and interaction with sediments and the atmosphere are poorl'y understood on the continental shelves; yet, these are the connecting link between the source of contaminant and ultimate dispersal in the dee-\ P, ocean. While the capacity of the deep ocean to handle wastes is great, the, problem is transport. There is also a lack of that information needed to understand the effects of physical stress on coastal environments. For instance, little is known of the effect of ice and icing conditions on the ability of the environment to handle waste materials. In fact the stress of long periods of darkness or sequential light which occurs in polar regions has been little studied. These areas are gaining importance in the scheme of things in the world and we need to know how photosynthetic organisms live during long dark periods, how organisms cope with long periods of below freezing tempera- tures and, conversely, how the same organisms manage under high light and temperature conditions. These@questions and many more need to be answered before extensive alteration of the environment is brought about by man's activity. 132 Part IV GENERAL RErOMMENDATIONS In the following chapters we examine the status of knowledge of estuarine ecological systems considering types one by one, their distribution in the United States and interactions with man. Whereas the knowledge about the organisms, sediments* water currents, chemical constituents, and other com- ponents taken separately is very great, treatment of the parts together as whole systems has been infrequent, Many of our chapter authors were forced to combine fragments from many sources to suggest the operationsof the ecological systems assigned to them. We do not yet know enough about most systems for resource management.. All too often th6 cause of some change such as' loss of a species popiilation is erroneouslyassigned to some immediate cause rather than to the ultimate cause that may be several steps removed in the chain of ecological-interactions. For example, a species disappears.and a disease found to be killing the declining stock Is blamed. Both phenomena may, in fact, result from a change in the circulation of nutrients in the estuary which is leading to the replacement of one ecosystem 9 by another. On the basis of the work cited In the Chapters to follow and with the ultimate aim of understanding enough of the main features of whole estuarine ecosystems to predict'the' consequences of proposed programs of action we give next some recommendations for extending our national and international capabilities in marine ecology and ecological engineering of the coastal'e6osystems. In@these recommendations we regard man as a part of many ecosystems and in commerce with others. The task before us is management of harmonious systems of man and nature for stability and sur- vival. Need for Management of Estuaries as Systems Any plans for the successful development, management, and regulation of estuaries of the United States must be consistent with the.ecological and economic principles by which such systems operate*with and without modern mano Because the systems of the water differ from the systems of the land in having moving-fluid, the land laws do not provide for sensible man- agement and new laws must be*enacted to recognize the limitations and re- quiremenis of marine systems. Principle of the Circulating Body as Management Unit An estuarine system receives its causal energy,from three main sourcest a) the sun's energythat enables the plant@s fooA-making processes to support living component ;..b) the organic matter from the rivers which supports other living component:j and c) forces of @rind, tidal motion, 'and current which circulate the water and with'it the necessary chemical substances, the plank- tonic microseopic'orginisms that constitute the estuarine farms,.and the gases, oxygen and carbon dioxide, whose regular flow is necessary to all the chemical and biological prdcesses of the estuary* All@ these pt-ocesses control both the natural industry of the bay and the systems that d@velop when man putsin and takes out materials, Thus the phosphorus, nitrogen, and other fertilizer elements necessary for the growth 133 of microscopic green crops of the estuarine farm are recirculated from the waste products of the clams, fish, and billions.of planktonic animals (water flea size) of the area. These biological systems support the aesthetic quality of the bays and their margins, regenerate minerals from wastes (even some from manbut not too much),, and keep the bay systems supplied with adequate oxygen. Because of their shallow character, such systems,serve as nurseries for juvenile fish-, shrimp, and other marine forms that make their fastest growth before migrating out to sea where they support commercial fisheries. A farm on land stays put and one may buy or sell its productive essence. A farm in an estuary swirls with the water. Title to a piece of the estuary bottom would not confer title to the essence of the bay since it is swirling and exchanging within its natural circulating unit. The first ' principle, therefore, is thatfor estuarine gement, plann regulation, and development, no plan can succeed unless it first defines the estuarine circulating unit as the management unit. These units are sometimes defined by physical constrictions and bars in the estuary; at other times they are defined by the way the water behaves, forming up and down circulations that hold plankton and characteristic nutrients as intact masses. The boundaries of the water masses my be changed by building barriers, although making bays smaller may diminish circulation energies and thus diminish the productive power of the system. As an example, take the Albe@,marle Regional Planning Program in North Carolina in 1967. Their maps showed their boundaries right across a marine bay as if it werea piece of still land. This is unworkable because any planning done on one side of the bay will be negated if something contrary is done to the same circulating water on the other side of the bay. It is possible to zone marine waters but only if natural units or man-made circulatory barriers axe used. Any new legislation must allow possession or authority over units of system circulation if management is to be scientifically sound. For-those-systems, which by migration export or import shrimp., crabs, and food fish to or from the open sea, there must be provision for management of the two areas together. Thus the subsystems are tied together into larger systems. Tha Need for Detailed Ecosystem Maps For Each State, Small scale maps were prepared*in our state interviews marking some, enimples of each type of ecosystem occurring in each state, but making no attempt to map them in detail. These maps (Part III-A) suggest the possibilities for detailed large scale surveys by experienced estuarine scientists and man- agers in each state, possibly in collaboration with a central team that can maintain some uniformity in symbols and presentation., These maps should refer not only to rigidly fixed systems such as clam flats but should recognize gyrals of circulation which serve to hold the integrity of plankton ec 'osystems and indigenous production. In the same sense that most states have soil maps, geologic maps, maps of vegetation, or land use maps, the coastal regions need these maps of marine ecosystems and subsystems. 134 Need for Recognition and Study of New Ecosystem Types With the creation of many kinds of industrial waste flows, the types of new marine ecological systems possible are far more than the few represented by chapters in this report. It was one of the purposes of the state inter- views to locate small marine estuaries which might be receiving new kinds of waste in isolation so that the estuary might provide an example of the kind of ecological system that develops with each waste. What we found in state after state was a pattern of many kinds of waste disposal into the same bays and harbors so that it was not possible to define a case history for scientific purposes. The search for these should continue. Many waste types such as metal plating waste and textile dye wastes, whose stream patterns are known, were not detected alone in the estuaries. The aid of industry in locating these wastes should be sought. Estuaries receiving waste over a number of years may have developed workable ecosystems which can be transplanted. Exper- ience with these new systems should help other industries with similar wastes. Need for Lagoon Size YELcrocosm Studies of New Waste Types Long used in the laboratory, the ecological microcosm is a small model system arranged to have the same inputs and outputs of lighttemperature, and chemical flows as real systems in the field. The model is seeded from the real one and somewhat restricted ecosystems develop, with many of-the basic properties of the field system. Especially where the consequences of a waste are initiating new ecosystems or modifying old ones, marine microcosm studies on a scale sufficient to include the fishes should be attempted. Such study lagoons are being attempted by staff members who have contributed to this report. Horton and Hobbie operate waste lagoons connecting with the estuary in their studies of effects of phosphate wastes. Odum, Chestnut, Kuenzler, and associates operate marine ponds receiving treated sewage at Morehead City, North Carolina. Rounsefell & associates (Zein-Eldin. 1961) studied a lagoon at Galveston Into which copper ore was placecL. These approaches allow a test of realistic inter- actions of whole ecosystems with wastes. Ydcrocosms are small enough to allow replication for effective statistical vertification of tests and if arranged with connection to the real bays, they are largeenough to have population pressures from the real system. Need to Explore New Waste Treatment Processes by Domestication of New Ecosystems The treatment of waters and wastes often involves captive ecosystems in concrete, which is an apt description of a sewage treatment plant. With so many kinds of ecological systems to consider for waste treatment, Mby do we stick to so few types. Why do we not domesticate some more types and help the self design processes combine species in unique new groups capable of new waste treatment processes for new waste types. For example, a beach is really a kind of filter bed which has character- istic organisms that are highly effective in mineralizing and clearing wastes from beaches. The intake to Marineland of the Pacific, drawing water through a beach of coarse sediment utilized an existing system for clearing sea waters. How about other systems such as shes, underwater grass beds, oyster reefs, and so forth? 135 Need to Evaluate the Stress of Fluctuating Waste Distributions The characteristic pattern in American estuaries now is patchiness of many kinds of poorly mixing wastes, stressing organisms first with one condition then another. Whereas plants, micro-organisms and animals can adapt by physiological change or by species dubstitution. to many changes such as increased temperature, they cannot readily adapt to many special conditions at once. Wastes that are now released irregularly or into bays so as to form lenses and patches my be processed so as to provide steady conditions to which organisms may develop new and special adaptations. The importance of the variation in waste releases of one or more kinds needs to be tested and the stress of variation measured in terms of variety and mass of organisms that can be supported. Need to Use Shellfish Coliform Data for Mapping Eutrophication Because of the early recognition of the danger to health of patho- genic micro-organisms in estuaries being concentrated in oysters and clams, there have been extensive monitoring programs in the states with restrictions on food harvesting from areas receiving intestinal bacteria from man's wastes. An opportunity exists to use the pattern of coliform bacterial distributions as an index to the nutrients which have been distributed at the s time. Need for Study and Resource Management by System Rather than by Species It has been a strong tradition in many state-organizations to make ecological surveys and consider the processes in a whole bay, often assigning a state biologist to that bay or region. In the Federal Government until recent years the organization of research and administration has been species oriented. This is partly because many biological scientists have been taught to isolate a species and separate all factors from the problem except the one under concern in order to isolate experimentally the effects under study. Partly it is because legislators and administrators have been unaware of the delicate dependence of larger species of fish and shrimp'upon the microscopic food chains and mineral cycles. Partly it is because a generation of fishery biologists were taught population dynamics of single species based on the premise that the rest of the environment was a steady property. the single species approach is important and possibly necessaxy, but has little predictive value where, for example, the decrease of one species is releasing resources that cause another to increase. Our surveys cite important data obtained in recent years by broader estuarine study programs of the Federal bureaus as well as by the states. This trend mast be accelerated. Fdrmers would understand that the most practical way to get good cattle is to develop a good food range and then channel the food to the desired animals. Our estuaries axe similar. The most practical way to use the sea's biological resources is to maintain a good production range and channel the,haxvest, whether the food base is algae, bottom plants, or organic matter flowing down river. The adequate.management of our estuaries on ecological principles may require changes in the structure of governmental bodies and recruitment of staff with an appreciation of the systems interactions. Programs organized by system my also correspond more closely with those of the corresponding state organizations. 136 Need for Return Payment to the Estuarine System It is a taken-for-granted principle in the economy of man that payment is made for goods and services and that such flow of currency allows each industry of the economy to maintain competitive survival. No person or industry is asked to provide some of its production for nothing since this would cause it to be competitively excluded. The principle applies equally to the management of natural systems. Man receives from the bay system and its components the yield of aesthetic recreational restoration, foods, ser- vices in processing,wastes, and other profits. If we draw on these systems without returning some exchange of special value to the estuary., we cause the aspects in which we are expecting continued yield to be diminished. A formula must be derived by which services that stimulate bay processes, such as encouraging desirable fish food chains., should be returned to the bay in proportion to the dollar yield from these bays. Such programs will insure that the bay becomes part of the economy of man and nature rather than a mining operation in which the bay soon has no further use for sustaining a viable coastal basis for human development. The feed back payment principle is shown in Fig. 1. How much effort is necessary to pay the estuax7 enough to encourage more growth of the type being harvested? There are precedents for this kind of program. For example, some of the Federal laws provide monies to stimulate sports fishing in proportion to the monies derived from licenses to take fish. Need for Enabling Mechanisms for Sea Harvest and Farming at Least Cost Partly because of the history of competition of sports,and commercial fishing, partly because legislators believe that little fishes if left to grow survive to become as many big fishes, and partly out of tradition, all kinds of restrictions are placed on the farming and harvest of the waters, which would seem absurd if placed on the cattle farmer. The way to control overgrazing is to control the amount of grazing, but not to raise the costs to the grazer.'.' If a body,of water is assigned to food production, it needs to be managed forits maximum yields of food. If assigned for sports fishing, carnivore chains need to be maximized. Estuarine zoning may set up one bay for sports fishing and another for commercial fishing. Where resource develop- ment is intended, enough title to that system through long term lease or other device is required so that large capital ventures can be made in its manage- ment to include whole bay fertilization, stock management, bottom control, etc. The shallow seas can be farmed as water systems.. Large bays will require large capital and methods should be proven on very small bays first. Our present system of mixing incompatible competing uses prevents us from attainment of mnximum values. Laws to allow management of the estuarine systems as units are required. Shellfisheries cannot be managed by them- selves since their food is filtered from the estuarine microsc 'opic farm (organic matter and plankton). The old bottom leasing idea ignored the water which must be managed with the bottom. Need to Preserve Some Locations with Complexity2 Aesthetic Yield, and Water Purity Where conditons in the estuaries are not severely shocked by changing water levels'.9 salinities, floods, and other disturbances, some very diversified Symbols Energy source closed dollar Self maintaining loop for boys subsystem payment Plants estuarine. management Work by one authority e flow on another Feedback work loop to help fossil: Storage ecosystem with fossil fuel fuel support in proportion to harvest boats .mineral cyclm work .plants Sun light rga Harvest f ishing work. ECOSYSTEM Fig.. le Energy flow diagram- with work payment to the@ estuary for its service to man so as to develop self stabilizing design of man and, nature a - Nate -that -the currency of humans flows in the opposite direction and by the above arrangement has a closed, balance of payments between the fishery users and an authority established to represent the interests of the ecosystem _(H. T. Odum). 138 (in species) living systems develop which have great aesthetic value to the recreation industry. Their associated clarity and purity of waters is due in part to the complexity of living things which are efficient at mineralizing many special chemical substances through organismal specialization. There are the interesting coral reefs in tropical waters, kelp beds in California, intertidal crops in Maine, and grass flats in many other areas. The variety of sea life2 ofskin-diving pleasures, or of scientific values cause these areas to,be of special consideration since they are easily destroyed with disturbances. These waters are in the class of National Parks and need to be set aside in such a way that the waters that bathe these systems do not mix with the waters serving other uses where there is turbidity,, industrial wastes) insecticides, etc. As more and more freshwaters are dammed upstream the floods to the estuaries in many places will diminish and then these com- plex and stable systems may develop in areas that previously did not have them. Need to Manage and Increase Areas of Estuarine Nursery In the management of the estuarine mar .gins, the importance of the marshes, the shallow underwater grassy bottoms, and other shallow waters must be emphasized since this is where enough light penetrates and is con- centrated to develop much of the productivity that supports food, sports, aesthetics, and ultimately cleansing power. The deepening of margins and the dredging for small boat channels and waterfront bulkheads essentially destroy these nursery areas because the waters are then deep and turbid enough to exceed the thresholdfor minimum light that scientists call the critical depth. The swirling, estuarine, microscopic farm is choked dead if the green cells are in the dark too much of the time, just as if a black cover were kept over a terrestrial farm. There are ways to have both marinas and nursery margins, such as by cutting marina into new land, but never at the edge of the bay. In cases of damage already done, regrading of estuarine bottoms to optirmm.production depth can restore productivities. The cost of this may be included in channel development projects as a necessary payment back to the bay for the special service extracted. Need to Manage the Total System of Land and Water The requirements of management of the circulating estuarine water systems are diverse and must be oriented towards many productive aspects of the economy. The past tendency for one-user group to gain full control of a bay without due process and ruin it for other uses needs to be, pre- vented in the future by placing regulation and development on a body which is charged to develop the water system for optimum pattern with the lands. surrounding. Presently the development of land systems without incorporating the water systems is a conflict of interest in which the public's rights are being given away often as means for attracting industry. Since the states are competing for industry and since the destructive navigational dredging programs are Federal:-some Federal action may be necessary. However., develop- ment needs the kind of private enterprise one associates with industrial- governmental-agricultural collaboration'in terrestrial farming. State 139 enabling laws are needed for full development of all the aspects of the estuaries. Regarding the -bays as a development and design responsibility will go a long way toward making state boards of Conservation and Develop- ment do positive things to their estuarine resources instead of following the policy sometimes developing by'default of encouraging their destruction bypermissive attitudes towards industries on land. Need for Developing Some Kind of Ecosystem for the Multiple Pollution Harbors In the heavily polluted harbors and urban waste centers found in most states, the nature of the ecological system is uncertain. Studies on the Black Sea) summarized 'by Kriss, show that a workable productive ecosystem can develop on top of an anerobic, bacteria dominated decompo- sition pool. With toxicities, fluctuations., and substances of new types, the harbors may not now exhibit such harmony of self processing of wastes. What can be done with these areas? At what level of waste disposal is a functional ecological system able to mineralize! What organisms may be preadapted to such a system? What is the relative cost to the nation of utilizing the harbor waters as decomposition ponds as opposed to con- struction. of 'waste systems? Need to Use the Wave, Tide, and Current Energies Compared to many environments,,'the estuaries have high productivity of plant and animal growth which may be due partly to high physical energies absorbed from tides, waves, and wind driven currents. The estuary provides means for converting some of this energy into the work of recirculating minerals, larvae, and food substances, thereby raising the levels of total yield. The amounts of these energies that are contributing to the estuarine resource have been measured rarely and the potentials which are available for estuarine management little considered relative to the biological and human uses of the coasts. Research focus is needed to map these energies and relate to their productivities, capacities for waste receival, and other aspects of the systems as a whole. An inventory of energy budgets, including all sources of energy contribution and stress loss, is .a means for generali- zation and management of the whole systems. Need to Utilize the Competition of Ecosystems That alternative formulas exist for ecosystems in the same area has long been known by those designing fish ponds. Small differences in the proc.'essing of fertilizer nutrients, manipulation of turbidities, and bottom changes can convert a plankton based food chain pond to a pond whose food. chain is based primarily on bottom attached plants. Systems tend to main- tain their own type by recycling their characteristic nutrient ratios of mineral elements, by supporting larger animals that have behavior programs for eating members of alternative systems, and by other mechanisms. In the management of-estuaries we have to learn under which conditions onelsystem displaces another and by what Imeans one system can exert negative influences 140 on another. There is the promising possibility of manipulating the control members of these systems so as to develop the system desired. Need to Test the Pulse-Reproduction-Migration Theory for Use in.Management Tested in our state surveys and chapters is An ecological hypothesis that explains many complex patterns of estuarine biology and provides a predictive basis for planning and management. In the course of a year there is a rise and fall in the intensity of energy inflow to an estuary as light, organic matter in rivers, and other sources such as waste. A system which becomes adapted and remains stable in a varying regime tends to program its reproductive activities and its migrations so that they correspond to the pulse in food availability at any point in the food web. Even the salmon migrations begin to make sense when one notices that the young, in the most critical periods of growth, are found in estuaries and other bodies at a time when the foods available to them are ma inimized. The further north a system is found the greater is the seasonal pulse and the greater the role of pulsed reproduction and migration. The entire system of shelf and oceanic fisheries slidesnorth and south in response to the pulse of the "production system and tap outgoing stocks from the estuaries, thus coupling all into a world-wide system of the seas. Many biologists find coordinated patterns at the large ecosystem level difficult to comprehend because their training has been with the organism first, the ecological system being "whatever the organisms do." We would describe the'system differently; because of the mineral cycles and the programatic patterns long since built into the seas, organisms are present which fit the system. They fit the pulse of energy well enough to maximize the total possible energy utilization. The addition of waste release regimes must be compatIble and steady so that adaptations are allowed to develop or be retained. Need for a Federal Role in Research and Development Coordination Whereas the management of particular ecosystems is well established in state resource management organizations, an opportunity exists for a Federal role in assigning its special grant and contract funds so ds to cover the main kinds of ecological systems, at the same time distributing' regionally the work load along natural lines. For example, if efforts are assigned in areas where systems are prominent, Georgia and Louisiana might do marshes and oligohaline systems, Florida the mangroves, Puerto Rico and Hawaii the coral reefs,, Maine the rocky inter-tidal system, Texas the hyper- saline system, California the kelp system.. Alaska the fjord systems, South Carolina the oyster reefs, North Carolina the beach systems, etc, etc. Need for Systems Simulation of Each System Type For each system, there now are energy and chemical flow diagrams in various degrees of detail and accuracy which permit computer simulation of proposed changes in input conditions. The procedure at our present state of knowledge may be sunmrized as follows: 141 .Based on field data and knowledge of the species an energy diagram is drawn showing principal pathways of food, work, and controlling chemical flows. The standing quantities in storage in various populations,, waters., and muds are indicated. These storages are called compartments. The flow along each pathway is stated in a computer program as proportional to the concen- tration upstream in the flow diagram. Growth is programmed by feedback from storage to flow. Some daily or seasonal patterns of inflows and outflov's,for the system are programmed. The program is run and the interaction of all the statements provides graphs with time for all the compartments. These graphs' are compared with observed patterns. The.discre-pancies indicate difficulties in the energy flow model so that it may be modified and tested again. The simulation thus provides a means for testing the consistency of knowledge about the parts with observations about the behavior of the whole, Simulation of one representative example of each type of ecosystem should be attempted now. It may be modified according to specific, problems whena, realistic program is developed for each system type for purposes of prediction of possibilities. Need for Compatible Use Plans and Estuarine Barrier Zoning Because of the mixing aspects,, an estuarine unit is defined by the circulation of water and minerals. Plans for use must separate and combine users and uses so that no incompatible uses are operated in the same bay. Thus shipping,, bilge watersp,poisonous copper bottom paints of shipso industrial wastes., and continuous dredging are not compatible with aesthetic,,. fishingp food., and purification aspects and should be isolated by barriers so that the waters do notmix. The hot water from large power plants takes the life out of the water that passes through and thus destroys the planktonic estuarine farm. This use may be compatible with the industrial uses but not with the aesthetic-biological ones. The values of the bays are large; for example., about $370/acre per year in,Corpus Christi Bay (Texas) in 1960. No one user claimed a preponderance of this value. Proper management may allow some systems for each purpose. The biological-aesthetic ones require large areas of sunlight as do fa=s. The industrial ones can be concentrated in small bays and channels in the same way that industrial cities are channeled. Water from one must notbe circulated into the other. Plans like the following-. need consideration. A Zoned-Sector Plan for the Multiple Development of Marine Bays* H. T. Odum *This section was distributed as a circular during Legislative discussions in Texas in 1960. Although the examples are from Texas,, the zoned sector plan is general. "This is a proposition for a zoned sector plan for the maxi:mum@. multiple development of the marine bays of Texas. With over a million acres of bays behind the beach lines, Texas possesses vast t42 and fertile shallow lagoons. Development of the investment and resource use is accelerating aver this new frontier but competitions and conflicts are already retarding progress* The value of the bays in their present partially-developed state is already about $370.00 per acre per year as estimated for the Corpus Christi area by Anderson (1960)., but the potential values are much greater. In Table 1 are cited present value estimates trom Anderson's study. of Many potential uses and users are excluded because there are no means and mechanisms for permitting harmoniousco-existence of state., federal., corporate and individual enterprises. Especially., are there difficulties in acquisition of titles and leases to underwater lands; no agency., no laws.. and no authorities are sufficiently broad to cover the multiple aspects of Use. Consequently there are no broad plans for me irnum development. Instead pressures develop between groups with efforts made to exclude competing users from the bays. Some of the specific uses and some of the conflicts between users are cited in the recent report on Texas Natural Resources by the Houston Chamber of Commerce. In Table 2 are listed some examples of the controversies and conflicts developing in Texas recently. From the data on values in Table 1 it is clear that no one interest is of such overwhelming importance to the general economy to permit exclusive use of the bays. on the other hand locally one user may have sufficient concentration of effort and investment and value.yield to justify a local dominance. What is needed is a plan to permit the best possible multiple use. to The proposed plan is based on a partial separation of users and investment leases based on zoning according to the nature of the activity and its effect on the water. By associating those users that can most readily be located together without conflicty maximum benefit can be accrued to the public good while allowing all users some right and position. The overall plan is pictured in Figure 2. "In sector 1 are located those users of an industrial nature whose operations tend to be harmful to the tourist., fishing,, and sports activities. This sector is for industrial use, maintained in deep channels for navigation. Dredging is permitted here for navigation and shell. Waste disposal is received here. Cooling-waters are taken from this sector and returned to the sector. The waters of this sector will tend to have minimal life. Fouling of ship bottoms and cooling intake pipes will be minimal. Harmful effects of wastess bilge waters, copper from ship bottoms,and.other activity will be restricted to this zone. The discharge from this zone will be directed toward the open Gulf as much as possible leaving the other sectors little affected. 143 Table 1. Dollar per Acre per Year Estimates of the Bays in the Corpus Christi Area(from. Anderson 1960) Annual Dollar Per Acre Values Industrial Navigation 64 Oil and Gas 124 Cooling 10 Waste Disposal ? Shell 5- Sub Total 203 Use Based'on Biological Food Tourist., Sports lAO Local Residents H Commercial Shrimp 13 Bait Shrimp 1-3 Fin Fish 0.34 Crabs and Oysters 1 Sub Total 167 Total 370 144 Table 2, Some Conflicts and Incongruities in the Marine Bays or Texas Proposed law to lease bay bottoms at a few cents per acre per year for real estate thus taking value away from present users such as shrimp industry. Propositions to exclude nets by sports interest. Proposition to exclude bay trawlers thus putting smaller boat trawlers out of business. Condemnation of bays, for conmercial oysters due to sanitary pollution and inadequate control of waste disposal. Argument as to responsibility of shell dredgers in restoring former reefs. Payment of money to restore reefs while live reefs are being dredged. Accusation that bait shrimpers and"bay trawlers are taking shrimp stocks while too small instead of waiting for greater value later. Dredging of navigation channels through rich nursery grounds. Fight over title to spoil islands. Argument between oil companies with pipe lines in shell areas and dredgers of shell. Conflict between duck grounds and dredging of grass flats* Stopping freshwater upstream affecting salinity., especially oysters downstream in the bays. Disposal of chemical wastes in conflict *th needs of fishing and tourism. Arguments over effects of passes and new channels on sports fish. Fights over waterfront right with tide lines varying and in doubt. Arg=ent over treated wastes and their fertilizing effects. Proposed use of maxine bays as freshwater storage to eliminate present uses. Efforts to increase tourist industry while dredging and pollution eliminate the nearby tourist beaches and fishing grounds. Attempts to develop a beach facility downstream from attempts to accelerate industrial development. Conflict over nuisance and odors of excess algae and needs for disposal of treated municipal effluents. 145. Z ed Sectors- in a River on' Typ@cal BW Low' Salini ty Industri.al Sector. Sector) bo trol Navigation Dredging Co6ling waters wastes �mall boat gap 0y8ters, Sport Reefs, Shell Dredging, leases Ygarina Aquatic Farming morina_!.,, Leases Shallowt grassy, clear water. high Bay trawling salinity Bay netting hery Bait Fis, Nursery for' young of thd offshore 6h 1IMP fishery Nur;sbry. ,Secto.v Jetties for all uses 4hereas this diagram satisfies some zoning objectives, It reduces Open Gulf wave and current energy, lowering productivity. .146 Sector 2 is the low salinity sector to contain the mouth of the river. Such water as may be allowed from the overall river basin plans upstream will thus be conserved in a relatively smbu area to permit an oyster-industry and'live oyster reefs so attractive to sports fishing. Oyster reefs of Texas must have brackish salinity. The oyster reefs are realigned into neat rows across the current for.maximum growth, for ease of management, lease., and access and also to permit removal of dead shell from the inter- reef areas. This sector will be turbid due to river contributions and dredging and will not allow ma imum light penetration necessary to best growth of fish food and shrimp larvae. Being of,moderate depth the area will maintain populations of larger species migrating from shallow areas. Some nutrition to the food chains is derived from the river inflows. A zone in this sector should be reserved for netting and trawling of boats too small to work regularly in the Gulf. Xis a premise of this plan that none of the marine resource users cam or should be excluded from the public resource by some other group with more political power. Instead conflicts or imagined conflicts can be solved by zoning to provide adequate area for each user large and small. of Sector 3 is the, shallow clear nursery sector. Both polluted waters and the turbIid river waters of varying salinity are excluded from the broad shallow areas., so that rich beds of grass may develop with maximum plant growth and nutrition for the food chains that provide maximum yields of fish, crabs., and shrimp. Part of this area is arranged and leveed for aquatic farming leases for underwater grass for cattle and shrimp,, crabs., food fish, and ,fish for the animal.food industry. Another part is reserved as an inviolate nursery sector for the offshore shrimp industry. Although the eggs are believed deposited outside, the microscopic larvae come into the nursery grounds to grow up before going back out into the Gulf where they are caught. This sector is also for duck hunting since grassy areas are part of food attraction. The shallows allow blinds to be put up. Administration of the Plan "No existing agency except the legislature now has the breadth of authority and interest to initiate a positive program such as required by the times for the full development of the sea frontier. Some kind of enabling action by the legislature is thus @he first step. Some appropriation and fiscal structure will be necessary as well as some engineering division for construction and maintenance. The unit for Planning must include the whole of a bay system if the zoning is to be effective in separating conflicting users. It may bethat 8 bay marine resource development districts (Sabine, Galveston,, Freeporty Matagorda, San Antonio Bay, CorPus-Aransa6-Copano, Upper Laguna-Baffin, Lower Laguna) can be formed corresponding to the 8 natural areas. Another alternative for administration May follow enabling legislation to permit users of harmonious association to create their own barriers consistent with overall zoning. In any case scme way must be found to permit the same kind of enterprise in the marine waters as on the land. It goes without saying that the idealized plan in Figure 2 does not fit any particular bay exactly and that the zoning and barriers must be adapted to local situations. 147 Difficulties Where tides are small, dividing bays' with dikes diminishes circulation, causing silting to more shallow depths, and some data suggest that producti- vities are reduced* Zoning needs to be arranged without eliminating the large circulation energies of wind and tide or preventing access of migrating popu- lations. Zoning Example, Georgia The possibilities of Marine Resource Zoning are illustrated by,Fig- 3 supplied by Eugene P. Odum,.University of Georgiap from some discussions underway in 1969. A general statement of Marine Zoning ideals was given by E. P* Odum (1968). Since productivity of above-water marsh grass is so , great, it was proposed that the productive heart of the tidal marsh be re- served against other exploitation as a "marsh bank" in the same sense as the federal "soil bank" program. See dotted loops in Fig- 3- Need to Utilize Natural Experiments In the management of large estuaries, manipulations are very expensive. If action programs are'instituted they should be identified as an example of a clas's of actions and studied before and after the change so that we obtain guidelines for future propositions of this class. For 'example, James To Darby and Clair P. Guess of the South Carolina Water Rec'ources Committee have writ- ten us of the upcoming opportunity to compare an estuarine system in South Carolina with and without a heavy river discharge. The Santee River which has been discharged through Charleston Harbor since 1941.maybe soon returned by engineering projects to its former channel further north to.decrease silting. Will total food harvests and recreation yields increase or decrease? Another exampleis the bypass ship channel into New Orleans through oligohaline Lake Borgne. Whereas over a hundred thousand dollars of-federal funds were spent on studies before dredging and duly reported, where are the published details of the conditions which exist now after the canal was dredged? The piecemeal,.immediate - crisis approach in federal agencies under the guise of economy is costing America large sums. The opportunities to find answers applicable to management of each class of ecosystem problems is lost because budgetary subdivisions sometime do not recognize it as their responsibility to follow through with published before-and.-after comparisons. Need to MA-i Organismic Biology with Systems Synthesis Represented by the new book by Green (1968) on the estuarine animals or by the Organismic Biology Research program at the Marine Biological Labora- tory at Woods Hole, Massachusetts are studies of important species and their role in the ecological system. They inciludelife cycles, distributions,- sea'sonal regimes, food habits, predators, and responses to various factors as SUGGESTED ME-ZOMES, GEORGIA ESTUARINE RE.G.IM-1 148 SAVANNAH RI CAROL IIYA A, SAVANNAH-, Industrial, port WILMINGTON I S. and waste ce, -4e C, I disposal SKIrjAWAY IS. V TYBEE IS. WASSAW SID. WASSAW IS. OSSABAW $D. OSSABAW IS. Q) LUDOW)CI Fisheries, 01 sr CATHERINES SO. Recreation Hunting BLVF F ST CATHERINES 15. SUTHERLAND DoubtPul J SAPELO SV. MERIDIAN FLACKBEARD IS. 0-6 Research DARIEN O-Y\cu VK@ I OLV\L e- APELO IS. -5 D Buffer zon' ALTAMAHA SD. @j Industrial,port andreer'eation BRUNSWICK X with limited waste dispdsal S T. SIMONS PS. ST. SIMONS SD. + -3:c SO.* 31. Wilderness LEGEND pr6serve or sea shiore park HOLOCENE -BARRIER IS, and fisheries CUMBERLAND E fORRIER IS. S7. (SILVER ISLUFF) Y's Wvt + MAINLAND PLEISTOCEN GEORGIA ++7 FL ORID11 C! MILES' Fig. 3 Suggested zoning for Georgia from E.P. Odum(1968). Dashed loops are 'tinarsh bank reservesil. 149 tested in laboratory controlled experiments such as temperaturet salinityt photoperiod, wastes, etc. In some examples where the diversity is small as with gribbles boring in treated wood, the organismic biology includes much of the ecosystemg but in complex systems such as coral reefs the single species study involves a small energy fraction and does not provide pre- dictability about the organisms in nature because their interactions with each other, their mineral cycles, and food chains depend mainly on other species. The organismic approach has a long honored tradition And there is much more to be done to understand even the species which are of sports and commercial interest, but the management of the ecosystems requires an under- standing of the behavior of the combinations interacting and it is the direct experimental study-of the system that may be the important focus needed, This may be,done by adding specialists in systems synthesis to the species teams* The Smithsonian Institute's efforts to add ecology to its species- oriented traditional approaches is an example of this approach in recent years@ Need to Program Man's Estuarine Interactions Over Longer Periods and Wider Areas The self-designing feature of ecological community adaptations are contirmously demonstrated along the coasts as populations in one area make temporary excursions an'd invasions of areas outside their main range in larval swarms and individual migrations and as temporary colonies. The gree.r crab, and blue crab in Maine make inroads and take losses that are in part correlated with temperature. The eastern-oyster makes northward invasions into the vici- nity of Cape Cod.in some years, The areas of substitution of one species for another in the same niche or the division of one niche among more than one species may expand and contract from one year to another in response to weather variations or a wave of effect spreading from population-dense areas, Our present means of planning, authorizing research, and concocting action programs may respond in a too sensitive manner to the rise and fan of biological stocks in local places* Local changes in patterns over a 20 year period may be reasonably normal and predictable at least statisti- cally* Many natural stocks provide for such variability with large year class storages. Man's planningg,his capitalization of fisheries and re- creation investments must also provide for long range stability* This can be done by larger storages to even out local variations, by coupling local utilizations to each other over larger geographical distances in the same way that the natural populations are coupled by shifting stocks in migration* Zones of central 'virility may move as needed distributing the gains and liabilities over'larger areas and times as one does insurance* Need to Unite Scientific and Economic Approaches Ce P, Snow's two intellectual worldsp one of natural scientific tradition and one of social science tradition need to be united by training more people in both traditions each learning languages of the other well enough to use them, Better yet the new trainees should learn both. In 150 our survey we find documents from the two backgrounds like two different worlds, dealing with the same estuarine-resources sometimes quoting each other in a perfunctory way, without really using the results. For example the book on Ocean Fisheries by Christy and Scott (1965) or the coastal plains economic study by Hite and Stepp (1969) attempts to understand fisheries as an economic system, without the biological system showing. This has as much chance as the converse study of biology of fisheries systems *ithout including the inputs and outputs of man's economy. They are both parts of the same system. In this study, our original proposal authorized some synthesis of the economic and ecological, but the administra- tive requirements for specialization caused an amendment to be issued later eliminating the economic synthesis from our effort. One cannot understand systems by breaking them up into parts unless one also has quantitative ways and a large expensive effort at putting the parts together againo Energy@-Dollar Calculation In addition to these dollar values we estimate the value of the work the ecological system is doing outside of man's dollar economy, With pro- ductivity and metabolism at about 5 g dry matter/m2/day and 4 kcal/g there are about 29 x 1017 kcal/acre/year of work processed in maintaining a use- ful part of the earth's life support. At our approximate rate of 10,000 kcal work per dollarg the equivalent money value is $29,000 per acre per year, As life support systems become scarce we might ponder the meaning of these high values. Systems Analysis and Total Systems Study Finally, ten years after its use in other fields, there are effective beginnings in the systems analysis of estuarine systems. One might cite the Stanford papers on simulation of production and oxygen patterns from knowledge of component processes (McCarty and Kennedy, 1967), The verv@- tility of systems analysis approaches is suggested in Figure 4. Showing through simulation how the parts produce the patterns of the whole may help with management of the species as parts as-well as of whole estuaries, However, the study of whole systems may not necessarily require this kind of systems analysis that isolates the parts and resynthesizes theme Soon for each type of system general organization, structure, and temporal behavior are learned. We may learn to recognize and predict the responses of whole systems to various treatments if they are considered by type as defined in our reports A systems analysis of the parts may then be replaced by knowledge of overall performance for each class of system. Often the program of the whole is what is required for management. We return to our theme of classifying the coastal ecological systems including those resulting from human participations. Through knowledge of the behavior of ecological systems, can we not plan for and manage a better biosphere? 151 1. System is divided into parts by area, species, process, storage category, energy process, or other basis about which some equation can be written 20;Flow processes are diagrammed and equations written for each. Flows may be components, sequences, mat- erials, energiest mathematical terms, dollars, correlation coefficients, or other quantities (flow lines). 3. For successive time intervals, starting with some initial storage conditions, the storages and-rates of flow are eval- uated and graphed with time for comparison with the observed measured real world. Fast computers make this useful. Fig. 4. Systems Analysis. 152 Part V Chapter A-1 ROCKYSEA FRONTS AND INTER-TIDAL ROCKS Rocky sea fronts and rigid man-made-surfaces that stand against waves in the inter-tidal zone develop characteristic-attached ecosystems in bands above and below the water level. Breaking waves, intermittent exposures to heating and drying, and problems of maintaining two regimes of gas exchange drain energies from other potentials by requiring special adaptations for mere existence. However, the moving water provida-Drenewal of nutrients and food, aeration, and partial protection from carnivores, adaptations which maintain dense masses of animals. The balance of special conditions associated with the water level produces characteristic bands of attached organisms such as algae, mussels, limpets, chitons, and urchins in crevices (Figs. 1-4). The rocky sea front has some pr9perties in common with the high velocity surface systems (Chap. A-3) such as high metabolic rate and concentrated food flows, but the inter-tidal surfaces have zonation associated with vertical light fields., frequency of wetting,amount of spray, hours of exposure to underwater food and carnivores, and wave swashing of-filamentous algae that act as a scouring broom. Communities may develop on rocky shores built by geological processes or on calcareous surfaces built by the plants and animals themselves. Variation and species substitution occur with latitude as tide and air mass exposures change, although the variation in the form of the encrust- ing systems on rocky coasts may be less than in more uniform environmental situations. Periwinkles, for example, charactetize the upper splash zones. Small Littorina ziczac on tropical sea fronts is replaced faxther north by other species of the genus. Like maxshes the intertidal rocky subsystems may be important to'the producing., consuming, and cycling components of the estuary. In the United States the intertidal sea front is often a neglected resource with potentialities for greater use of algal beds and mussels,, and for the trapping of fish and crustacea that move into these beds with the tide. EXAMMS Cool Sea Fronts of the West Coast, Hedgepeth (1967) provides a diagrammatic view (Fig. 1) and an introductory account of rocky shore zonation. Fig. 2 from Kirk (1962) shows other views of principal members of rocky shore ecosystems from the Washington coast. Principal members from the southern California coast are shown from Emery (1960) in Fig- 3. F@oc k lou,5e 153 Limpet Acorn barnacie ,@J PeriwinAle 5 TA, j Rocksnail(Thal,@' ko@xkweed5: Fig. I. Pacific Coast rocky zonation Pei;'lehoovs (From Hedgepeth 1967b) . k turban 3Zil n California muss@l Z- barrele Feather boa Aelp Purple urc in Och, st Ai ple shore ea palm . 'r1q, Red urchin 0- ---7- cra qia qreen anemone -I- Larnin HOCKY S 0 ROCKWEED inch Fucus furcatus PERIWINKLE Lifforina sp. inch HIELD LIMPET cmaea petta 2--inches inch ACORN BARNACLE Balanus crenatus 2 inch s 2 inches MUSSEL Mytilus edulls inch Fig. 2. Rocky Coast animals of the Washington coast(From Kirk 1962). 154 Some common plants of rocky shores in south- ern California. 1, wave and U spray zone: A, Ra@(sia sp. (XO.04). 11, high-tide zone: B, Pelvetia fastigiala (J. Ag.) De Toni (XO.09); C, Endocladia muri- cala (P. & R.) J. Ag.'(xO.5). 111, midtide zone: D, Gigar- fina canaliculata Harv. (x 0. 15); E, Gigarlina lepi,@rh),nchos J. Ag. (XO.15);.F, Corallina.wn- D E F x couverensis Yendo (X 1.5). IV, low-tide zone: 0, Gigar- fina spinosa (Kutz) Harv. (XO.04); H. Gelidium cartila- gineum var. robustum Gardn. X 0. 15); 1, Phyllospadix torryi S. Wat. (xO.02) (habit); J, Egregia laevigata Setch. x 0. 1). H Some common _Vanimals of rocky shores in southern Cahfornia. 1, wave and spray zone: A. Littorina planaxis Philippi, periwinkle (X 1); B. AemaeadigiialisEsch- OA scholtz, limpet (xO.5). 11, high-tide zone: C, Ultorina scutulata Gould. periwinkle (xl); D, Acmaea scabra (Gould), limpet (xO.5); I, Fig- 3. Rocky shore Balanusgiandula Darwin. acorn animals and barnacle (xO.7); F, Tegaofu- plants (From B I OD nebralis (AI. Adams), black tur- Emery, 196o). laws of Pagurus 1P., A . , , hermit crab protruding; . G, Pachygraps- crassipes Ran- dall, common lined shore crab (XO.15). 111, midtide zone: H, My- filus caftforniarna Conrad, Cal- ifornia sea mussel (X0.15); 1, Nultalina californka (Reeve), N California chitin (x 0.3); J, Ma- palia muscosa (Gould). mossy C chitin (xO.3); K, Mirefla poly- M merus (Sowerby), gooseneck barnacle (xO.25); L, 8alanus lintinnabulum (Linn.), red and white barnacle (xO.25): . M, Tetraclita squamosa rubescens Darwin, thatched barnacle (xO.25); N, Bunodactis elegan- liSSiMa (Brandt) (xO.15). IV, low-tide zone: 0, Antho- pleura xanthogrammica (Brandt). @green anemone (xO.15); P, R Spirorbis sp. (x3). Q. Stron- gylocentrotus franciscanus (A. ?Bh TD VE @H Agassiz), red sea urchin (xO.35); R, Astraea undosa (Wood), top shell (x 0. 15). 155 In a middle section of the zones of attached organisms at Pacific Grove California, barnacles and an attached red alga, Endocladia,, predominate (Fig. Glynn (1965) defining this zone as a subsystem r purposes of study, considered its structure, food webs, and overa" processes. Food available to filter feeders such'as the barnacles was estimated by season (Fig. 5). This zone was exposed between 446 and 95% of the time (Fig.6). The herbivores and carnivores of the rocks were found to move across the zone with the tide, providing energy drains as vell as regulatory actions for only part of the tidal-cycle (Fig. 7). Total plant tissue (standing crop biomass) representing the balance of photosythesis by the algae and loss to the consumers showed a pulse in the spring when light and nutrient conditions were best. The most active part of the life cycle (Fig. 8)was in the spring, and the nitrogen content per unit of algal tissue was diluted at ttLis season. Photosynthesis occurred in and out of the water but decreased'when the plants dried out of water. Based on these and other measurements and experiments a diagram-of biomass and food flows for the system was drawn (Fig. 9). one of the characteristic species at Pacific Grove was a tiny bivalveY Lasaea cistula, which shoved continuous reproduction in the rather narrow Fa-nge c7f temperature characteristic of the region (Fig. 10)" but with a pulse corresponding to the pulse of light (slightly leading the temperature pulse). As represented in Fig. 11 frcep Reish (1968) piling in more sheltered waters, in the shade of wharves, or in turbid inshore waters., may have animal components predominating over algae. Jetty Rocks of the Gulf Coast Firm rocky surfaces on the Gulf coast are mainly the man-made rocky jetties, such as those at Port Aransas, and Galveston, Texas, which have a high seasonal range of salinity and temperature. Patterns of zonation acco'rding to environmental factors were studied by Whitten, Rosene, and Hedgepeth (1950) and Hedgpeth (1953). The tidal range, the wave amplitude and the seasonal shifts in mean sea level are all of the same order of magni- tude: 1 to 4 feet. As shown in Figs. 12 and 13 zones of different organisms are, narrow in the inter-tidal region, grading into associations including Arbacia urchins, characteristic of high velocity 6urface systems (See Chapter A-3). Whereas the green algae at the surface show some increase every.spring with increase in light they are,kept in check by grazing of the periwinkles and other organisms. The green alga, 'Uiva, was fcnmd to dominate the south Jetty at Tuxpan, Mexico in 1958 in vaie_rs subjected to freshwater stress and city wastes. Inter-tidal Algal and Mussel Beds of Maine As one moves northward on the Atlantic coast, geological formations in Massachusetts shift from sand to rock and tidal ranges increase from 10-to 20 feet or more., Exposed in varying degrees, the much dissected coast of D Vq D I ON I> al ID 10 0 o (> 0 0 06 A; t:f tj 0 0 9 11. t- w tm 0 'o eb 0 00 015 oI- 0' u I, p 0 m 0 0 0 + 1., 0 0 0 '33 "v: 0 p 0 0 + (b0 013, (1) l,' 11 1-4 0 P) g 0 -0 P, (o :11 51,w 40J 0+ 1. a tr P, F. 04, Co 03 50 m I- -0 IN (b ED 90 10 W+ oo' (p Uo M M to 0 $0 .- 0 c+ i,- - PD @L cr 0 10 K I to 014 m I-, to I., C, n ED ID 4 1., 0 + 11. -00 V o to w p f@ `5 + . + to to *+ 0 0 + to 0 m 00 CL AIISOLUTV COMPOSITION (ML WET SETTLED ML WET SETTLED VOLUME VOLUME/IOOML) PER NET HAUL m w 0 0 0 N 0 0 o T LIN tQ #0 0 m 0 14 ?!. 'o (00 C q 0 I-t 00 .0 up C. C. to W-b cr% t, In 00 C', t:r go '. 7. 1, E. 0, On go z o- 0 -co W@ co -1 x '07* o o Ul E-r to z z cir @n ci. a- C+ w 0 0 0 0 -n 2. n. t6 gr - J., o- E- 0. 0 951 .0 e: q w - a W R r BALANUS GLANDULA ENDOCLADIA MURICATA 157 9.0.- S.O.. W UW 7.0- "UPPER LIMIT." _j 6.0. _j 7. W 5.0 MEAN HEIGHT.. MEAN 0 WIDTH co 4 4.0 3.0. W DOTY x GISLEN (1946) 2.0..- - - (1944)- - "LOWER LIMIT" HEWATT +11.0 (1947) GISLEN (1944) Comparison of the vertical ranges of B. glandula and E. muricata at the Hopkins Marine Station as established by various workers, with. the vertical position of-the 16 quadrats collected from the Endocladia-Balanus association. Upper and lower limits represent the over-all vertical range of the Endocla- dia-Balantis association'in the vicinity of the quadrat sites. Fig. 6. Tidal relations of the barnacleialgal zone (GIY=y 1965)- A, 41 4 4 NV a 00 0 a 09TMTUS IR WATER C)EXPOSED AT LOW TIDE b)AWASH C) SUBMERGED AT HIGH TIDE SLUK TURNITONE 11 DIPTERA A LITTORIN SCUTULATA T94VL 01UNEORALIS WHELKS JACANYMINA, THAIS) MENOCCLAVI -SALANUS ZONE Movement of some transient species into, through, and above the Endo- -ladia-Balanus level during a rising tide. 4E N 4)-- Fig- Movements of some carnivores with rising tide (Glynn, 1965) A 158 car00spores Cc.rpogoni in\ sper ti GAMETOPHYTE(n) Spermatongium )r (5r GAMETOPHYTE(n) tetraspores (n) meiosis TETRASPOROPHYTE(2n) Major events in the life cycle of E. nutricara, as adapted from KYLIN (1928). Seasonal variation of E. muricata (dry weight) for study areas 1, 11, and ITT. Each monthly figure represents combined data from three field samples. Month Standing crop biomass g/ 2,034 cm2 g/m2 Seasonal average g/m2 April, 1959 44.9 221 SPRING May, 35.7 176 189 June, 34.8 171 July, 31.0 152 SUMMER Aug., 29.7- 146 128 Sept., 17.4 85 Oct., 25.9 127 Nov., 19.0 93 AUTUNIN Dec., 8.3 41 87 Jan., 140 24.0 118 WINTER Feb. 12.6 62 79 Mar., 11.7 58 Fig. 8. Reproductive cycle and seasonal record of growth of red algal dominant in barnacle- algal zone (Glynn,, 1965)- TRANSIENT MTRANISIENT CARNIVORES HERBIVORE + LARGER BENTHIC PLANTS AND THEIR EPIPHYTES RESIDENT SCRAPING a GRAZING HERBIVORES 80 W ENCRUSTING ALGAE Z Z B PROTIST N FILM 15 0 RESIDENT ICARNIVORES_ 0 60m- W Z MNIVORES 4 a SCAVENGERS A. _j Z -14 040-- Cr 0 0 W _j FILTER FEEDERS ir a) 20.- Z W W Z LL) 0 j 1 -1 1 1 1 A a: F M AM J J A S 0 N D W CL MONTHS Three year monthly means of the percent of adult L. cistula brooding tt young (solid line), and inshore sea water temperatures at Pacific Grove, L J___. California (broken line), for the years 1959-1961, i__576_h@_G70-67- I I SEAWATER! AVAILABLE' I Fig. 10. Reproductive activity-of a small snail 2 8 % OF SHE TAE - -I PLANKTON 8 ORGANIC DETRITUS SUSPENDED IN THE SEA member'of the barnacle-algal association 50,000 me DRY WEIGHT W17K IZ.5 00 1. 0 PROTEIN Block diagrams showing average dry weight biomass and protein content of the organisms of the Endocladia-Balanus association, grouped in categories according to food relations. The area of the shaded and solid block for each group is proportional to its dry weight biomass and protein content per m2 (see key, lower left-hand comer). Arrows show the main pathways in flow of food. Unknown quantities of certain groups are delineated by broken lines, and for the encrusting algae and protistan film an estimate of the very small quantities present is shown in a magnified view. \0 Fig. 9. Bnergy diagram for the barnacle-algal zone (Glynn, 1965)- 160 INTERTI DAL ZONATION &--Chthamalus fissus 'lop, 6?e W%O- -Balanus amphitrite Splash zone Balanus amphitrite Chthamalus fissus Balanus crenatus High tide- zone -Mytilus edulls amclus fissus -Chth Mid-tide zone -Bugula neritina Mytilus edulis tyela pficata. Mid-tide zone Bugula neritina Styela montereyensis -Myti Ius edulis Low tide zone Fig. 11 A. Intertidal zonation in Alamitos Bay (From Reish, 1968). 161 Settlement and Growth Rate in a Population of Mytilus cclifornioaus 0 0 0 0 aD 10 0 0 Ile Weight in grams 0 0 0 %% 0 JI % cli % 0 0 %,A- No. of specimens 0 0 0 %% 0 b,' 0 0 0 0 -0 W (D 0 0 0 0 in rn E E 860 191 12, 61 60 / ?/ 6 60 60 3-61 %1 @/61 Y62 61 611 0 Time: June 1960 Y60) to June 196.2 z 62 Graph showing'settlement and growth rate of a population of blytilus californianus in Ventura County Marina, California Fig. 11B. Succession on a California jetty (i@eish, 1964a). 0 162 TOP OF IETT -6! Tide at 6ahle3ton, lVay Tide at 6alveston, Noy. 5- CbMamalus Siphonaria 1-ittorina CIGUIva 6 S Oyster3 0 Thai$ 4 k Red alfae ,7P Pa dina Arbacia ledge) 3 0 Bunodosoma Q / 7-@t- i . . 7 10 All t V, . ......... V 7 ;> q 7 P P q a P p 0. 13 1 1 129 CONCRETE @ILE IM 5 114NER IETTY OUTER JETTY. R y f 9,4 MOY 21,1967 Noil Z9 mayef Nov R9 1 May.2f Diagram representing zonation on concrete piling and jetties at Port Aransas, as observed on November 29, 1948, and May 21, 1951, with the predicted tide curves for the two-week period preceding observations superimposed. Fig. 12. Zonation in western Gulf of Mexico where tidal range is small(From Hedgepeth 1953)- t63 -GUL,,P- >- A, M qy@ \-\A VA\ X\ L\J Mytilus, 5a2anus, Q@ Lworina irrorata I/ PY'r q Pqr@\\777 ---------- .01 pas@ ce) fie loop 0 09a Ma ha, S 1,Db Onarid, C) IWorina ziczac JWH 19+7 Schematic diagram of relationships of intertidal jetty fauna with climatic zones and latitude. Characterist-x@ members of the fauna are indicated. Fig. 13- Comparison of intertidal zonation in the western gulf. Northern jetties receive large variations in salinity, whereas those further south have higher ana more stable salinities (Whitten, Rosene, and Hedgepeth, 1950). 164 Maine with its inlets and archipelagoes, has a large representation of the intertidal rocky ecosystem made up of heavy beds of brown algae, beds of mussels., and such carnivores as starfishes, green cxabs., and lobsters that move into the system wher it is inundated. The mussels filter the products of plankton systems from the water and regenerate nutrients among the aigdl beds which, after photosynthetic growth, return organic matter to the plankton systems bathing the rocks. Chapman (1964) provides diagrams from Lewis of similar beds in England (Figs. 14 and'15). Chlorophyll a content of the various layers is given in Tables 1 and 2 from Gifford a3i E. P. odum (1961). Tropical Atlantic Intertidal Rocks On Margarita Island, Venezuela (Fig.,16) zonation is presented by Rodriquez (1959) as shown in Figures 17-19 and 21. Here salinities are high and vary little. Whereas ecosystems under water were found to be tropical, diversified, and very different from*those in temperate latitudes, inter- tidal zonation war. similar to that of temperate regions having few species at a time and with periwinkle, barnacle, red algae and urchin zones. Some niche substitutions were observed. In Fig. 18 the stressed outer zones were characterized by the green alga Ulva whereas the less exposed surfaces had other algae. Zonation data for TFMical Africa are given in Figs - 32, 34, and 35. Tropical Pacific Intertidal Rocks Doty provides information on zonation on intertidal rocks in Havaii(Fig.20). Similar data are given for the West Coast in Figs. 29 and 30. Examples of Intertidal Surfaces Affected by Wastes The green alga Ulva may be characteristic of harbors that axe heavily affected with wastes s=ucas sewage that constitute a fertilizati6n as veil as a stress in oxygen variability and other properties. When Eniwetok Lagoon was receiving heavy shipping Ulva andfttercmon@! developed on intertidal surfaces. These algae were ars-bprevale-nt in waste-laden San Juan 11arbor in 1963, and McNulty, Reynolds, and Miller (1960) reported their distribution On rocks and posts In.the vicinity of the sewage outfall into Biscayne Bay near Miami, -Florida7See Figs 22 and 23). The encrusting, attached ecological systems of the rocky sea fronts form a steady state, with algae continually growing and being grazed back. The system has considerable ability to groom) clean) and,.mineralize substances that tend to be deposited on the rocky surfaces. For example, Ceram(;-Vivas (1968a)reports that rocks around San Juan, Puerto Rico experienced fairly rapid return,to normal. after a large oil spill there. DISCUSSION Exposed versus Sheltered Sea Fronts Sea front ecosystems receiving heavy wave action with spray undergo some energy draining destructive action but may be better protected from intertidal heating and drying than those of quieter coasts. Several authors 165 Tables 1 and 2. Chlorophyll in intertidal algal zones of Now England (Gifford and Odum, 1961)e TABLE 1. Average chlorophyll a in four zones in the intertidal region. No. of Mean Standard Zones samples W-2) deviation I. "Black" (100% coverage)* 25 0.80 =!: .009 0.48 Black" (6317c coverage)- 25 0.50 2. Barnacle (1000/0 coverage) 52 0.27 :t: .001 0.19 3. Fucus-Balanus (100% cover- age) 50 1.47 :t .051 0.86 4. "Seaweed" (100 % cover- age) 50 1.04 :i- .009 0,68 Mean of all zones 175 0.82 52 Two values are Wven for "'black" zone-one is the "neentration within the patches of algae and the other vahle is average concentration for the zone as a whole (tvh,ch is not completely covered by plants). TABLE 2. Inter-zone comparison of chlorophyll content in grams per square meter Zones S.E. of compared. difference differences t P 1 vs. 2 .23 .03 7.4 >-01 I vs. 3 .87 .12 7Z >.Ol I vs. 4 .54 .14 3.91 >.01 2 vs. 3 1.19 .13 9.6 >.01 2 vs. 4 .76 .03 24.6 >.01 3 vs. 4 .43 .16 2.8 >-01 See Table- I for names of zones. ED Grey lichens C". qp M Orange lichens Lcm;574 L. Conraws Verrucar/a ve"Uco"a 12 L.Avmoeo V 7 Pelvefid Barnacles W t !I L,PyYm0V0 mytilm A If "A)'4 'V M AcfiN7 F sp#ah@; s Barnacle F evesic "Yk" , .( /w/osus reves"c'losus ij Fxes Lauranda' Ascophyllam Nr Gigarl"a Rhodyrrem;7 a F serrotus Red algae b1hothavnty'17 Lamkma I IR, 11 Lommarfa Diagrammatic representation of one semi-expoSed and Diagrammatic representation of types of exposed shores two sheltered shores around Anglesey, wave action decreasing around Anglesey. The slope on the left represents a sjulple extreinely from left to right. On the sheltered shores the influence of slope and IMPosed shore with jew species superimposed upon the barnacles. substratum upon the large algae is shown. No attempt has been The other slopes show slightly less exposed shores and indicate the inade to include animals other than barnacles (after Lewis). i7ifluence of ledges and clefts upon the distribution of Mytilus, FUCUS Var. evesiculosus and Thais. Although shown separately Mytilus and Fucus often occur together. The depth of the black zone has been considerably reduced: on these shores it would probably be at least twice as deep as the barnacle zone. Note that Patefla, Littorina neritoides, L. rudis and Porphyra would also ;j; i@j be abundant but are not shown (after Lewis). Fig- 14- Atlantic intertidal zonatior 1: nzi oiR (ChapmEm, 1964). S16., VA-IT -'I-' _7 T. --- ---- --j-)j--r---I- IT 15 14 14 13 Station 7-13 =12 -12 a -9 7 G -4 4 3 Stv;., 1-2 2- slw- 14 0'= mt-le1*1 of 0 F 22 1 j 11,11159 514 -1 1 1 1. t m;n Comparison of the distribution of inter-tidal algae in relation to tide levels. Fair Isle, Yune-yuly 1952. Dark bonds for exposed coast, Plain for sheltered coast (after Burrows et al.). aN CIN Fig. 15. Algal zonation in the North Atlantic zonation (Chapman., 3-964). *A Sw w 64,00, 83,411. T- ----T@ to 0. 167 MARGARITA ISLAND LOS FRAIC& VINIEZVEIL-A- STATION 9 0 8 10 is STATION 4 NAUTICAL 14ILCO &TATION1 UAWS*1940 LA ASUNCION 04 A PAM LA R&STIPIOA PONLAMAN LAGUNA LAB HARITE STATION 8 cuq@* S.4 STATION IF I < Map of Maragarita Island, showing position of stations. Fig. 16. Location of Tropica 1 Zonation Studies by Rodriquz (1959) on North Shore of Venezuela. ALOAL StLT TRANSEG T A B rrTIT1 SPLAB" CONC SPRAY ZOMM A -9 SUBMERsto Cam. CAULERPA 00M. POILYCHARTE Ea cam. F @15 $A" qD 69. CRAMPOVA Rovic "PIA" ULVA ED 078SURELUAN FASCIAM 5 D lilt[ SALAMUS LALWA"IA lilt PAPAL*" Stition 1, substation Transect A-S. Fig. IT. Transect of intertidal zon.ation on Margarita Is-land facing the sea. A @A (.A i7. i;@ > 0W > v rA OA >C. @A -4 1.4. 1.11 L" LA @A LA 0 rm rt _0 0 M c %. 0, 10 0 @'o n > 0 www" '.A ai -J -4 -4 J 0@ 47% :4 113 0 1-4 4A (T 1. > z 0 Z vi z (710 rt CD 0 m Q rt 0 c: . . . . . . co 0% Q t-9 x U) 60 @A i.A iA i-J ZA Lill Z FA- 3! 0, I 0 m PI j; m 14 0 (A 0 LITTORAL ZONE x im z SUBMERSED ULVA @-k0 COMMUNITIE1 DALAMUS L-!TTORI LV?KOTHAM @............... coolum P EROGLAD IT 0 SrONE.5 IAUN4 -01R.1 04 A 0 I- Ty"or"A HMO^ Vl p \-o PTCROCLAO BALA 'ii@ 0 0 n L-YTHOTHAMMIA 0 PTEAOGLA OLY IOALAMUS TrIoltilf .4 A -YYMOTHAMMIA bPTE"-Lj -AL A M . I A7 [email protected] OF COMMUNITIES AT DIFFERENT ROCKY SHORES, MARGARITA ISLAND 991 w rr 0 p cl JQ f" z z to 0 (a r C: + Do r, ,: ............. . cr rn w z+ 101, 12 > m a MU)E: lag i; :0@@ oo C+ r- r \0 ot ALOAL SPLASH SPRAY BEL T ZONE ZONE 1-b C+ W N 0 0 :3 BALANUS NERITINA C+ 0 CALOOLOSSA Z NERITINA 03 tq p 4 0 us TORINA 0 FILAMENTO LIT o to THAIS 0 AAPOAE :3 isopoos tq w 9 ALANUS CALOOLOS@SA W BALANUS THAIS C V MYTELLA NER,I TINA 691 FJ- x N rn > z 4h, 0 v Cc z u L . - 0 rn N N 0 0 x 0 cr w 5 m x U) x x x X 0 x x C+ x x X x I x x x x x x x x U) >4 C+ a CD 1. oq ca -n 0 0 C: CL r NG) v) rm rj A 0 C+ tp to lb co 0 kt 93 WE OZT qQ oq CD z x z .z m 0 @-t t,J 0 CL N x 101: &M C+. ci- 0 @10 ON a >1 p > rn rn rnz H- (D z > -4 v U) 0 z -rb AC2>c x x x x 0 x x C+ x x CD x ,go F- @ x x x x tu Fj. ri) 0 Ask. x CD x 3C -addift 172, have diagranmed the change in zonation from exposed sea front to sheltered sea front as a naxrowing of life zones occupied by populations. Niche substitutions and/or species elimination occur in the change from one regime to the other (see examples in Figs. 12, and 24-26). Vertical Zonation Many authors have diagrammed vertical zonation relative to the levels of the tide, such as mean sea level, high spring tide, splash zone, etc. In different areas the species occupying the various tidal zones are different due to niche substitution, the complicating action of salinity variation, and other factors. Some of these diagrams are given in Figs. 19 and 27-30. These zones may be considered in terms of the energy support for the populations. The upper spray zone grows microscopic plants such as blue-green algae and diatoms which are grazed by periwinkles. A few barnacles may set in this zone in exceptional spring tides, but they are so seldom under water that they do not grow appreciably. Next is the zone,of regular immersion which supports bright-light-adapted algae, barnacles, oysters, and other organisms capable of existing between periods of immersion and able to filter long enough to grow,but are out of water enough to limit predator consumption. Experiments like.that of Crisp (1964; Fig. 31) show the increased growth rates and final weights possible when barnacles are under water for longer periods. In the lover part of the barnacle zone intraspecies competition may be important when predation is restricted. Below this is the zone of brown and red algae, relatively large plants with auxiliary pigments capable of a better growth when suspended in water, but with heavy tissues which are slow to desiccate and which can carry out photosynthesis when exposed. Mussels are associated with this zone, serving as nutrient regenerators. Seasonal Patterns The pulse of energy due to light is important to intertidal. ecosystems in temperate latitudes,and heating stress in summer restricts inter-tidal development in lower latitudes. The change in sea level with season also controls development of intertidal zones as demonstrated by Stavanger, Norwaz and Breivik (1957) on the coast of Ghana where light and temperature changes are not so important (Fig. 32). Two periods of reproduction and larval releases were found in Miami (Fig. 33) corresponding to spring and fall energy pulses in light energy. Succession Lawson (1966) in Figs. 34 and 35 shows algal succession with Enteromorpha first, Ulva next, and other species predominating later. This pattern devel also at7 -Port Aransas, Texas when new jetties of fresh pink granite were added to an existing jetty. In the spring Enteromorpha was first, then massive growths of Ulva,, and then brown and red algae characteristic of the old jetty. One factor in 'te succession was the developopnt of animal populations which grazed the heavy initial growths of greens. 'for role of grazers controlling the algal composition and of carnivores controlling composition of attached animals, see experimental quadrat studies of Connell (1961) and Castenholz (1967). Exposure ShOer to) Sheltered Ehores' Littoral 41g E@posed shores zone Li E.H.W. S. EH-W-S Eulifforal zone Littor.1 iLLLLI j I I I I zone 1 T11 E.L.W.S. Sublittoral zone - - E.L)N.S. The proportions and positions of the littoral zones proposed as they may occur around British rocky coasts. Greater variation does exist, however, for on sheltered shores with a large tide range the eulittoral zone may be several times deeper than the littoral fringe, while on exposed shores rvith a very small tide range or under conditions of greater exposure on mild, northern coasts, the littoral fringe may be several times deeper than the eulittoral zone. Under special, local conditions the upper limit of the sublittoral zone may rise more steeply than that of the eulittoral (after Lewis). N Fig, 240 Change in intertidal zonation bands with exPOsUre to WaVes (Chapman, 1964) W EXPOSURE ............. SHELTER ............... . Z0*j- ... . ....... ....... NZ fus ow CHTNA4141.0S ANDIoR 6 C -4 , / A 03. rErRACLir I LA. ON N CHL 0 Fig* 26a Variation in intertidal zonation -Zonation related to exposure in South Africa bands (Chapman, 1964). Fig. Variation in intertidal zonation bands @11 fill I 25 (Stephenson, 1944). 04 v o ct uQ EA .. ..... o :r Olt .01 0 CL to -0, V, N Zw PS, co cr t;j w 0 0 rL o X(D 0 m oa' ,n Nj 0 r N, ro cr P Q u q Phl .2 wz 0 Sl N@,. 4 Qs. ....N@) IV ei. 0 ;u m CL (D In GD All" n4 173 SPLASH ZOIVL SURRALITMRAL ZONZ W IfforilUAL -7.0 xtrtme h4hwaker- Vqyda ------- Hiq)wst @qh tide- Suprobetoral-Extrernehigh miter- Utlorina \ I frmv Upper shore Rhodochor too planow -6.0 -TF. 7 lRi -or I %arnacle3 "I Acmaea _Mt praslaa rage bigh tuk ------ --------- LittorinascuUm MioAlwcrh9h 'ter LVPh0JJPh0M4 Pach $us 4.0 U Teg ",M Middle shore 1[@N- SEA I -L L Midlittoral mytilus mean hit er low ..1h r Ir; Vlydfums I T&ije=rqtn'a!i&._Z,o II Microcladia...' tiytilus^0114', N N zzwp 0 _.AvtrdqtIow tk&-- P01YSIPhOnk r &A@- (4 - 1 .1 Q@ 1.0 N cortillina I Halosaccion Iridophycus i0endens re !a Vlean bsw low 0. 0 %a, UfPer limit of Loorer jhord Lominaria I water ;b sinclairi Phyllospodex i rtin Lami,narja --1.0 Infralittoral bi, ra 41, fringe C j Axtmw4 low water- - ------- J-006t low t* - ------- At I it low war- L andersopii -2.0 SUBLITTORAL ZONE C 0j,,tM-=fj. SOTIVAL ZONE INfRALITTORAL Z Yonge Doty Ricketts Calyin Stephenson LaJolla,l Pacific Grove, Calif. 'Postelsia Pt: Wash Calif. IHEIWATT, DOTY, 194.6 PIGG & MILLER, ------ I I RASMUSSEN 1937 194-9 --- 1@ .in Mussel Hewatt A LVE -ANIIV a Point 5trip SHELFOR.1), ;! -13. P F_E LC g., J%. 1939 @19 ---------- etal.1935 9 SIPLASK-12 I ZONE 'BALANUS- a -11 oc Raffsia Littorina LjTTopuNA ---------- 'a' Pr,2.5io2a 3'tkand B10MV a -10 C &maea Z, digitabs9 Endoclodia ....... &UPPER 8 on _INTERTID& 7 allar0ula "na s .2 '0 pbnaxis ZPWtelsla 6 .5 x*:: Acmaeq a Mytilus -Mitella -5 7CRVSTOSE 6igortina ------ RED$ Icristata Halo- 0 B. glonduld. jaccion it L_Tcutubta Endoctoda;Pe2vetia Ij Porphyra , fucus Ir C.LOWER )?e 71ILk '-Myti- L-Iqdbp)7vr4 5-INTERTID& 3 LO -coo 361q. Alaria 2-0 agard. `-9 -2 Z,-q.5 1- y C I idowh t7accidurn Egregia 7)al Ayt'e'l luas 'a 0 C Tbrunma Ulm D. -0 Zonardinlija 14' ois" DE ERSAICLO 15 IY It &Iarhna co ;yW7bi7era Z M It r 0.1_co I Iroids, C,22",th. V. C. ro fylo svnq@s &c. ent ot,4 Cyjtosejra:andPrsonJi Laminarz@ 4 aminaria- -2 r. -7)_ andersmi, 0 4lVereocystis PiAget Sound@ SHELFORD,1935 "'a P 04_ T @F_ a- PC N S A, ;A - Myt'l" a- L2@0 s M T lr@'I-uyd 'u M Cxl I., d Pa Y, 'a _ , [email protected],_ .3 C 1, c'. Fig. 29. Comparison of intektidal zonation of different authors L 0 p 0 p ........ ......... ............. ----------- ...................... CORRESPONDING TIDE LEVELS AT SAN FRANCISCO 009 @A cog xc 4-6 IP C+ 0 c7l 00 ;CC In ro -rq 4a g@a 4 Z OFp r 4: C+ 105, 1: otn X r tm C) 9z; @zj 10-3. GROSS PRODUCTIM-YINmi 0j Im--IDAYx 0 0 0 0, 0 0 ell 0 BIOMASS: PER UNIT AREA(Mq/crrM 4 RA r- 0 0 zi z rn I:s 0 0 0 0 0 0 0 CiN 1-b > u, 0 4 0 z 0 rn K 0 .0 15 0 z 0!, t30 0 rn Z -3T b z 1@0 0 '3 0 8 'r;g DRY TISSUE-WT. PER UNIT AREA fob EQUIVALENT PRODUCTIVITY gm Clm"IDAY. @L8- C+ 0 Q p 0 0 0 00 ct Z 0 0 400 70 5 E 60 4 0 040 3 ,30- 2 0 f -20 300 10 0 0 @'DIJ F M A 0 YA'S'0 DrJ F M A MJ J A S 0 N 0YF'G'M'J J A S 1952 1953 1954 1955 2 Relationship between seasonal tidal changes and the zonation and quantity of Hypnea mu3ciformis at a station on the coast of Ghana. Continuous line is the tidal curve of the heights of the lowest of the low waters in each month. The broken line represents the seasonally fluctuating upper. limit &H),pnea and the dotted line the percentage cover of H .)pnea. (After Lawson, 1957.) Fig* 32o Seasonal PatternsIn Africa (Lawson, 1957)- 100 :1963 11964 ,5 1965 50 /1962 25 Jan. Feb. Mar. Apr. May June jujy Aug. Sept. Oct. Nov. Dec. Settlement of Balanus trigontis on glass panels at the Miami Marir@ Research and Test Station, Miami Beach, March 1962 to July 1965. Fig- 33- Seasonal patterns in barnacle reproduction in Miami (Werner, 1967). @1. @65.. Y' GO 1-4 PERCENTAGE COVER PERCENTAGE COV 0 0 cr zz w S. CD 0 9. x E. 0 :3 Z I- L) m > :, @l m Im 0, 0 !a c-- . cr w 0 0 ON Ll 0 :3' =r Q, :1 ri ol pr m 0 L. 0 gin CL 0 ON 180 Chapter A-2 HIGH ENERGY BEACHES Rupert RiEidl and Elizabeth A. YjcYahan University of North Carolina Chapel Hill.. North Carolina 27514 INTRODUCTION High energy beaches axe sandy shores which receive strong wave action. Wind-driven waves and currents pound the coast, and the hydrodynamics of these waves, plus the daily ebb and flow of tides, sort the sand into zones of coarser and finer particles. Fig. 1 shows the majoi zones in' a beach environ- ment. This special ecosystem, with its shifting sands and pounding waves, in- cludes a very specialized biota, the sand dwellers or p sammon. S ome of the sand fauna are found entirely below the water line, gome high on the beach, and some at the drift line where organic rubbish accumulates. The epipiammon (shore- birds, fishes, certain beetles, etc.) live on the sand surface; the endopsammon (snails, bivalves, crustacea, etc.) burrow beneath the surface; and the mesop- sammon (diatoms', ciliates, tardigrades, turbellarians, gastrotrichs, gnathos- tomulids, copepods, etc.) live between the sand,gr'ains. 'The beach with its sand fauna forms-an extensive food filtering system, t@aking@ from the inrushing water nutrients in the form of detritus, possibly dissolved materials, and planktonic or larger organisms. Some of the macrofauna of sand beaches axe shown in Fig. 2 taken from Pearse, Humm, and Wharton's (1942) paper on the ecology qf sand beaches at Beaufort, North Carolina. Interstitial fauna are shown in Figs. 3 and 4 from the papers of Delamare (196o) and Ax (1966). Special ;ocomotory, respiratory, and morphological adaptations permit the psAmmon-to'inhabit a shifting environ- ment that may be alternately flooded and exposed to de4ccation, where oxygen tension my be low., and where waves beat ceaselessly. EXANFUS OF HIGH ENERGY BEACH SYSTEM Some examples of much-studied beach systems are the following. Gulf Coast: Port Aransas, Texas A map of the Port Aransas beach area and a typical beach profile are given in Figs. 5 and 6. In summer, especially, there axe steady southeast winds creating a stable beach structvre and a long shore current running northward. Figs. 7 - 9 and Tables I - 4 show seasonal variations for a nui@be'r of parameters in the surf zone at Port Aransas: temperature and salinity,.fish populations, OF TPA ONGSHORE WAVES CURRENTS AWARD RETURN FLOW. RIP CURRENTS -@WINO WATER OSCILLATORY WAVE WAVES NSLATION (BORES)i L COLLISION SH-.BAC.-ASI4 MOTION COLLAPSE ;SE rSWA -T BERM CREST DYNAMIC OFFS14ORE BREAKER SURF TRANSITION SWASH@ ZONE PROFILE SEDIMENT 0 COARSEST COARSER BI-MODAL COARSER *IND WINNOWED SIZE TRENDS COARSER GRAINS LAG DEPOSIT LAG DEPOSIT ACCRETION PREDOMINANT ACCRETION EROSION TRANSPORTATION EROSION AND ACTION EROSION SORTING BETTER- POOR MIXED POOR BETTER ENERGY INCREASE ------ HIGH GRADIENT ---)P HIGH Fig. 1: Schematic diagram of a high energy,,'aeach environment showing major zones relating to sand motion. Cross hatching indicates zones of high concen- trations of suspended sand grains (From Ingle 1966; Fig. 116). 00 182 mud M55afius Oliva 5inum Polinices Terebra -AIN. Donax Dosinia Cardium Venu5 Macrocalfi.5ta Tagelm c od';. ,YF naeus E rMn rit-a Ovaripes plosquilld C Pd P Leildopa ovis @Wwsd u5nedft Fig. 2: Yacrofauna (endopsammon) of sand beaches at Beaufort, N.C. Burrowing snails, bivalves, and crustacea. (From Pearse, Humm, and Wharton, 1942; Figs. 4, 8, and 10.) a b c d e f g - ,.Convergence chez divers groupcs interstitiels. a, Protodrilus Copipodes psanintipes inarins (d'apn@s WILSON). a, Nitocra cla (Arcniann@lide). - b, Coelogynopora sp. (Turbellari6). - c, Michaelsena cheliferi femelle, vue dorsale. - b, Arenoseielia spinicauda, male. - C, Goffinella "r Itylifer, montrant les ovicacs appliqu@s et les crufs de grande taille. - d, Para- (01 t igochke). - d, Cili6. - e, Trachelocerca (Cili6). Proschizorliynchus eptastacus brevicaudatus, femelle. - e, Emerronia gracilis, male. at" (Turbellari6 Rhabdocoele). - g, Urodasys ndrabilis (Gastrotriche) (d'apr@s REAtANE, 1953). Fig- 3: Wsopsammon (archiannelids, turoeilarians, oligochaetes, gastrotrichs, and copepods), minute organisms which live between the sand grains on beaches (From Delamare 196o; Figs 44 and 85) > gq ............. j.I....1-M.. za, CA w 0., tO 0" .9.0 r "04 z tn z @o --g ME c: CY C) tz Fh 0* b, .0 ID C+ c+ IN 0 0 D 4 cf)0 P, PI co U) m L :3 V) (D S. 0 0 @gg m 0 0 0 0 0 rI F@ C+ C) P, (D r- 20. C\ PI I CA 0. 0) C+ C+ @-4 0 C+ 14 (D Fh r CD r (D :S.,E :7 !3 rn Ea, - 0 @-w Pi 0 m W F4 P) ID P) cif (D PD lin 0 0 :3 0 0) 185 ARANSAS PASS REDFISH BAY DIRT ARANSAS CORPUS CHRISTI j. GULF of MEXICO "PADRE ISLAND PARK PITA ISLAND Fig- 5: Map of Port Aransas, Texas beach area representing a high energy beach system (From Oppenheimer and Jannasch 1962; Fig. 1). HIGH TIDE LOW TIDE P w _nd LONGSHORE TROUGH 3 0. 1 St LONGSHORE TROUGH w a 4 0 50 100 150 200 DISTANCE FROM SHORE (FEET) Fig. 6: Typical beach profile south of Port Aransas on Mistang Island, Texas (From McFarland 1963a; Fig-1). 186 36 Z w 32 TEMPERATURE 28 24 LLJ 20 LLJ 12 F-: 0 0 N D -T-j F M A M J J A S 0 'N CL 38 a- 36 SALINITY 34 t: 32 Z 30 DIRECTION OF W 28 LONGSHORE CURRENT 26 N N -@-@o 1 -- 0 N D J F M A M J 1 J 1 A N 1959 1960 TIME OF YEAR Fig. 7: Seasonal changes in temperature and salinity of the surf zone of Mustang Island, Texas (south of Port Aransas). (Prom McFarland 1963a; Fig. 2.) 20,000- 10,000 5,000 w 1,000 500 CD -j 100 50 - 0 10 No Collecti @5 1 A S 1 0 1 N J 1 F M I.-A I M 1960 TWE OF YEAR 1961 Fig. 8: Seasonal changes in fish biomass (pounds per acre) in the surf fringe at Mustang Island, Texas. High values for December 15, 1960 and March 1, 1961 represent mostly specimens of Magil ce @@@DIRECTION @OF ONGSHORE CURRENT ,phalus and Galeichthys respectively (From McFarland 1-96'3b; Fig. 1). 4- 3- RESPIRATION (RI (R) 2 - I- 0- CC W (P,,) 2 - NET PHOTOSYNTHESIS, (P') I.- Uj _Ai O__ z W 0 U) 5- (D 4- GROSS PHOTOSYNTHESIS (P,) (P") 3- 2- I 0 T 0 N 0 F M A M J j I --A I _S__T -0 1959 1960 TIME OF YEAR Fig. 9: Seasonal changes in plankton production in the surf of Mastang Island (Port Aransas), Texas, as obtained by.the light-dark bo 'ttle method. Yeand and 95% confidence intervals are shown (From WFarland 1963a; Fig. 4). 0- CL o P@ w 0 1 = =@F :",0 Z 00- 1.c r, '77' (D sm lb rl < Ch 1-3 w o 4: " (D -4 C@ -4 Cn t112 Ln C) -: : : . C) m 4@ t -410 -4 Ul ON 0 m 0 @-b Cn F-; 0 In Co 'Wo 10,01 m I'll In @A CD 10 L. 00 10 co CO 0 1@6 n N., @oW C7\ F-b 01\ EO F-b I-A _x F-j cc m 0 so CO W t4 t.4 cc co N7 m Qn Ic, -4 cf- ;A ND co NI F& t,z tz N2 \L rV ci- CC C-24 t.2 In 63 N7 41 Table 1: Continued DaLe of Colleclien, specir. May July July July Aug. Aug. Aug. Dec. J... J.". Jan. Fh. Feb. Mar. Mar. Mar. Mar. Mar. Apr. Apr' Apr. May May Ju-0 July 25 12 19 29 11) 111 26 is 13 18 31 9 l? 1 10 20 24 29 11 is 28 26 31 22 7 Eucinostomus argentens .... .... - ---- .... .... .... .... .... .... .... .... .... ..... .... .... Cono@on nobilis .... .. ---- - - .. . .... .... .... .... .. -.. .... .... ... .... .. .. .... ---1 429 .... .... 15 Bairdiella chryStIl"a 8 8 42 .... .. 16 13 1 12 1 22 2 .... .... -.. .... .... .... ---- Sciacnops ocellata .... 1 1 .... I .... .... .... ... .... .... ---- ---- .... .... .... .... - -.-. .... .... .... . .... .... Leiostomus xanthtirus 75 .... 10 42 27 57 .... 26 .... .... .... .... .... 10 .... .... .... Micropogon ujidulatus 2 7 .. .... .... .... .... . .. .... .... .... ... 3 .... .... .... .... .... .... .... ... ... .... klenticirrhus americanxis 23 ... .. .... .... .... .... .... .... . .... .... 5 ---- ---- .... .... I... .... .... .... .... .... Alentivirrhas athinticus .... .... .... .... .... ..- .... .... .... .... .... .... -- 3 .... .... .... .. . .... .... .... 1 .- 200 .... Menticirrhus fittoralis ---- 36 136 154 247 54 401 .... .... .... .... .... 8 .... ..- 11 16 31 10 25 77 40 25 Ill 77 i,ogollias cromis ... .... -- ---- 4 .... .... .... .... .... .... .... .- 53 4 4 ---- 1 1 2 3 3 4 Cynoscion nebulostis 2 1 2 2 3 2 .. .... . 17 .... .... - ---- .... .... .... .... I 1 1 Lagodon rhombuides 3 39 5 5 .... 2 2 26 10 .... .... 1 59 1 4 9 7 13 91 25 2 28 Archosargus probatocephalus .... .... 3 2 3 6 2 .... .... 3 .... .... I I I I .... 2 7 6 3 Chat-todiplerus faber 1 1 .... .... 1 2 1 - .- .... .... .... .... .... .- .... 5 1 11 13 4 19 ,rrichim-us lc(pturus .... .... .. . .... .... ... --- .... .... - .. . .... .... .... .. .... 2 .... .... .... .... .... Suomheromerus maculattvi ---- ---- 1 2 .... .... .... .... .... .... .... ... .... .... .... .... .... .... I .... 10 ---- Peprilu., paru .... .. .... .... .... .... .... .... .... ---- .... .... .... .... .... ... 168 - . .... .... .... .... Paralichthys lethostigma 11 1 1 .... .... .... .... .... .... .... .... .... 1 .... .... 6 2 5 2 .... .... .... Filefish .... .... .... .... .... .. .... .... .... .... .... .. .... .... .... .... .. . .... .... .... .... ... .... .... 3 Lactophrys tricornis .... .... .... .... .... .... ... . .. .... .... .... .... .... ---- I... .... ---- -- . .... .... .... .... ... 1 Sphaeroides nephelus .... .... .... .... .... .... .... 25 .... 3 .... .... .... ....1 2 -.. .... 2 .... .... ... .... .... .... .... Opsanus beta .... .... - ---- .... . .. 8 .... .... .... . Ifistrio histrio .. .... ... .... .... . .. .... . . .... .... .... Totals 568 1335 2754 2564 444 290 1126 547 16 44 71 151 122 35913 87 2172 579 617 538 662 1001 1020 2830 .508 419 OD 1-3 q CA TD 1-4 0 (D 0 0 P. ci- C+ M (D vb 0 0 P 'J% tn 10 w Ln @o W 9' 0 a @t (D O(D 5n SH OIN 10 co 0 t+ 04 ci- co - - - m P, P) 0 F F 1P (D :,j co 0,-4 .4 @-b PD CD 0 1- c-F f4 @c co FJ p p oQ T.-I C+ (D C+ (D Pi C+ C+ ID to I m (D M 0 ol -4 C+ M !No P F' F- P, Fl F4 (D 0) tin m 0 4 061 191 Table 3: Estimated dry weight of Donax meat and shell in grams per linear mile of beach at Mastang Island (Port Aransas, Texas) (From Loesch 1957; Table 7). Wte 1 2 3 4 5 A .... p June 27, 1951 .................... 422 440 246 246 282 327 August 3, 1951 .. ............. 299 317 88 246 229 236 September 3,1951 176 88 35 100 September 29, 1951 5.3 1.8 1.8 1.8 7.0 3.5 November 17, 1951 .......... Concentrations could not be determined. December 16, 1951 .......... Concentrations could not be determined. June 2, 1952 .......... ......... 352 229 229 950 154 405 June 27, 1952 ................. 18 53 123 158 194 109 Shell: June 27, 1951 . ...... 8,018 8,360 4,654 4,654 5,358 6,346 Augu.-t 3, 1951 ..... 5,591 6,023 1,672 4,654 4,351 4,351 September 3, 1951 .. ...... - 3,334 1,672 665 2,014 September 29,1951 . ...... 103 34 34 34 133 66 Novernher 17, 1951 .. -- Concentrations could not be determined. Decernher 16, 1951 ..... ... Concentrations could not be determined. June 2. 1952 . ........... ...... 6,688 5,681, 4,351 18,050 3,686 7,695 June 27, 1952- .... . ......... 334 1,007 2,337 3,002 3,686 2,014 Table 4: Observed predators of Donax at Mastang Island (Port Aransas, Texas) (FroM Loesch 1957; Table 8). Predator Comments Birds Catoptrophorus semioalmatus (Eastern willet) Stomach analysis, 4 of 6 contained Donax Crocethia alba (Sanderling) Observed eating Donax on beach Squatarola squatarola (Black bellied plover) Stomach analysis, I of I contained Donax Fish Menticirrhus spp. (Whiting) Stomach analysis, I of 5 contained Donaz Leiostomus Xanthurus (Spot) Stomach analysis, 2 of 6 contained Donax Pogonias cromis (Drum) Stomach analysis, 2 of 9 contained Donax Crabs Callinectes sapidus (Blue) Frequently observed eating Donax Arenaeus cribrarius (Spotted) Observed eating Donax Ocypode albicans (Ghost) Observed handling Donax at night Boring Snails . Thais floridana (Conch). Observed holding Donax; although drilling Oliva $pp. was not observed, many drilled shells were Natica duplicata (Moonshell) found. 192 phytoplankton productivity, and clam (Donax) populations. Table 4 lists observed Donax predators. East Coast: Beaufort, N. C. Some of the sandy beaches in the Beaufort-area are shown in Fig. 10. The outer banks (Bogue, Shackleford) axe examples of high energy beaches, while Bird Shoal, Shark Shoal, Fivers Island (location of the Duke Marine Station), etc. are more sheltered. Diurnal variations in temperature, vapor pressure, and evaporation rate for a Pivers Island beach were measured by Barnes and Barnes during their study of driftline spiders (Fig. 11). Fig. 12 is a comparison of night and day activity of spiders beneath and outside the drift at Pivers Island. Fig..13 gives carapace length frequency of the little mole crab, Emerita talpoida, collected on three occasions in the sil r of 1940. Table 5 lists the organisms caught in seine hauls and rake nets on sand beaches of the Beaufort area in 1939 and 1941 in the study by Peaxse, Humm, and Wharton (1942). Table 6 gives seasonal data for shell length for Donax and Olivella. Table 7 shows the condition of female Emeritas (with eggs and/or maleTat different time periods. PHYSICAL ASPECTS OF HIGH ENERGY BEACHES Occurrence Sandy beaches are found on all continents and on most islands. Their occurrence is related to coastal age, to local hydrodynamics, and to sedimentary processes. Coastal age depends on the movement of sea level relative to land (Fig. 14). This results in large paxt from isostatic changes - an effect of storing and releasing great ice masses at both poles. Beach formation and physical structure are based on wave energies and highly selected sediments which form the inorganic subsystem. These, in turn, are derived from the conversion of solar energy into the dynamics of atmospheric pressure patterns, part of whose energy is transferred to waves. In open ocean, with a fetch or runway of over a thousand miles, waves grow to maximal dimensions. 'From stormy areas they travel as swells with increasing speed, crashing finally against coastlines where they release their energy in erosion or particle sorting effects. Of all sediments known, sand (particularly @;hat of medium size) is most easily eroded. Silt and clay, as well as gravel and cobble, resist erosion, but sand is trans- ported. Since sand has neaxly similex erosion and sedimentation speeds, sandy coasts.are by far the most common systems in coastal morphology. Young coasts (Fig. 14) are those that are recently sunken or are sinking into the sea, exposing their terrestrial erosion pattern to surf activity (Valentin 1952). They are characterized by steep slopes, bending and winding outlines, and generally rocky shores (for example, the Aegean or Dalmatian coasts). With ageing, coasts begin to accurmilate coarse sand in sheltered bays, and their outlines become more and more straight until in old age straight coastlines with long, lined up sandy beaches are dominant, as on the east coast from Long Island southvard. 193 tAU f Fj- f 10 gin A OWN MAPkPH < 4 INS 14 51,0 10 22 4@-- lb Poe -T 17 ", I I ---, . I 14 11 41 B09UE BA Fo ft M. 11 IZ 19 14 7 ]z 17 fo 1 1 4 5 10 1 141 4 9 9 34 2S 26 9 Z 13 3 C% 7 11 11 17 8 29 1 1 2 z %% Z .3 2 SHACKLEFOPtR 20 10 19 % BANKS` 12. S '7 4 7 10 '41 jib 9 4 3 Is Fig. 10: Mp of Beaufort Harbor,,North Carolina. Water depths are given in feet (From Pearse, Humm, and Wharton 1942; Fig"' 1)."' 194 SAND SURFACE 6o'c AIR - BEACH UNDER DR:FT 55 C_ UINDE R DR FT - SPARTINA Soc- I" ONDER SURFACE 45 C - 401C 351C - 30% 25`C 11- ::@: ----------- 2A - 1 15 C - to C - 5*C 11 1 3 5 1 9 11 1 3 5 7 AM PM A 'A JUNE 17, 1952 Temperature variations on Piver's Island on a SuMmer day AIR 12cc - BLACK SAND BEACH UNDER DRIFT BEACH BLACK SPART NA UNDER DRIFT SPARTINA 11c. - 0WHITE SAND BEACH locc - .WHITE SPARTINA Occ - '212 7 Po ice 5cc 6 4cC > 4 \ ........ 3 2 Ice 0 7 9 AM 11 1 3 5 Pm 7 9 11 t 3A. 5 7 9 AM 11 1 3 5P. 1 9 It IA m 3 5 7 JUNE 17, 1952 JUNE 17, 1952 Variations in vapor pressure deficit on Piver's Evaporation rates under fhe drift on Piver's Island on a summer day. Island on a summer day. 40. AIR UNDER DRIFT 12c, - 0 BLACK ABOVE-SAND BEACH is SAND SURFACE lice - a BLACK ABOVE-SPARTINA @30 10 cc - 0 WHITE ABOVE-SAND BEACH a WHITE ABOVE-SPARTINA U 9.c - .25 - SC4 220- 7.c 4,c >10 N"\' 3cc 5 Zee I cc 0 7 9 AMII 1, 3 5 7 P., 11 1 A'M 3 5 7 7 9 11 1 3 .5 7 9 11 1 3 5 7 JULY 17, 1951 Am PM JUNE 17,1952 Am Variations in vapor pressure deficit on Piver's Evaporation rates *over the drift on Piver's Island on a summer day. Island on a surnmer day. Fig. 11: Graphs showing diurnal variations in temperature, vapor pressure deficit, and evaporation for air, sand surface, and over and under drift on Pivers Island beaches (Beaufort, N.C.) on a summer day (From Barnes and Barnes 1954; Figs 3, 4, 5, 6, 7)- 195 too. SPARTINA BEACH cc 75, So Fig. 12: Comparison of the activity of the spi- p 25 U z der Do-Dulation be- w @ 0 0 neath and outside of the drift during day '@e 25 and night on Pivers cc Island (Beaufort, N.C.'j SO (From Barnes and Barnes < 75 w 1954; Fig. 13). z w 100 1 2 DENSITY NIGHT 0 DAY Fig. 13: Carapace length fre- quency of the mole crab,-Emerita talpoida collected during the SU r of 1940 at Beaufort, N.C. (From Tt.1 J- z c0lection Pearse, Humm, and J-1 25 calkcti- Whartonl942; Fig. 18)."-. % T-t-- c juj 196 Table 5: Results of collecting on sand beaches at Beaufort, N.C. (From Pearse, Humm, and Wharton 1942; Tables 6 and 7). 68 Seine Hauls Rake Net Catches (Si, r i939j 1941) (summer 1941) Bird and Bird and Locality ............... Ft. Mnron, Ft. Macon, Sheepshead Place ........ Ft. Macon, Ft. Macon, Sheepshead Outside Inside Shoals Outside Inside Shoals No. of hauls ........... 21 20 21 No. of hauis.. 10 163 Is 6 15 No. No. No. times Ave. times Ave, times Ave. Summer ..... 1939 194i 1939 1041 1939 1941 Portunid Crab Arenaeus cribrarius ... 7 2.4 1 0.1 Sand Dollar Z ZZ Z Z Z Frequency ... E. E. F- E- mellita d 6 0. 6 z zZ Z Z Z quinquiesperforala ..... ... 10 8.2 Bilverside Blue Crab Callinecles sapidus. 3 0.5 3 0.3 3 0.2 Mepiidia menidia 10 112.7 12 ISA 2 56.0 8 4.0 6 24.5 10 116.8 Anchov Lady Crab Achiye,iella Oralipes ocetialus ..... 2 0.1 3 0.2 2 0.1 mitchilli ....... 731.7 10.3 150.2 20.3 Mole Crab 1(illifish Fu.dulus Emerd. Wpoida ...... 1 0.1 2 0.1 maj'alis ........ 10-5 54.311.3 5 2-i 3 13.5 641.2 Portunid Crab porn 1 0.1 Trp.allnio."& Callinectes ornafu# .... 1 0.1 garolinus ....... 811.4 42.3 2 0.3 .. .... .. ..... Hermit Crab hfi.h Pagums longicarpvs... 3 0.3 12 2.3 @.-oglon Flounder . ., ide ..... 20.2 .. ....10.7 3 3.2 .. .... 20.3 Lizard Fish Paratich1hys dentatus 2 0.1 4 0.3 snyodus jactens . .. ..... .. .... 3 2.7 1 0.1 1 0.2 1 0.1 Blue Crab Qdlinecle* N sapidua ........ 20.3 7 3.4 6 2.0 3 0.7 11. 2.5 orthern Kingfish mentieirrhus gazatilis ........ s4.2 a 1.4 10.3 .. .... 1 0.2 1 0.1 Flounder Paralichthys dentatus ........ 20.2 2 0.2 4 0.5 2 0.5 5 0.3 Flounder Paralichthys albiguttulus ..... .. .. .. .. .... 20.7 .. .... .. .... .. ..... Portunid Crab Aranaeus erib,ari ........ 50-510 5.1 .. .... .. .... 1 0.2 1 0.1 Croaker Micropogon Undulatus.... 6 1.41 .. .... 4 3.4 .. ....... .. "tole "Crab" Emerita kdpoida ........ 10.7 1.1 1 0.3 6 1.0 .. .... .. ..... Hermit Crab Pagurus longirappus ..... .. ..... 30.3 .. .... 2 0.2 1 0.5 6 2.4 Jack Caranx hippoe .. .. ..... 30.5 .. .... .. .... .. .... 10.5 Itfullet Mugif cephalu... .. ..... 10.2 .. .... 6 4.0 .. .... .. ..... Spot .. Leioslomus zanthurus ...... .. ..... 21.0 .. ....41.8 .. .... 10.1 Pipefish syngnwhus fuscus ......... .. ..... 20.2 .. ....20.1 .. .... .. ..... Lady Crab oralipis occUatus ..... 20.3 30.4 .. .. ... Trigierfish Balistes ear,Winensis.. ... .. ..... 20.1 .. ....30.4 .. .... .. ..... Snail Terebra dialocata. . . . . . . 10.1 1 0.2 .. ..... Beach Clam Donax wriaUlis ....... .. ..... 30.9 .. .... .. .... 1 0.2 .. ..... Ascidian Sfirda parlita. . . 1 0.3 .. .... 1 0.2 .. ..... CtLeo.p..hor; '.1 '1 0 .......... 1 41 Is 'i8 .. .. .... 197 Table 6: Lengths of shells (in millimeters) of conmn molluscs on Fort Macon beaches (Beaufort, N.C.- (From Fearse,' Humm, and Wharton 1942; Tables 9 and 10). Olivella matica Donax variabiliz (Picked up by-hand) (Sifted from sand) No. Date No. exam. Max.. 'Ifin. Ave. Locality Date exam. Max. Min. Ave. June 17 ..... 1090 9.5 2.1 4.8 Sbeepshead July 19 ..... 224 13.0 3.0 5.8 Shoal ..... June 76 15.0 4.6 8.9 July 21 ..... 164 12.5 2.3 7.6 Sheepshead I Sept. 1.0... .. . 103 10.0 2.5 5.4 Shoal..... Ju:Y 2 51 13.0 5.0 8.5 Dec. 7 ..... 71 9.0 4.1 5.7 Sheepshead Shoat.... . Ju y 4 94 12.2 4.7 9.9 Sheepshead Shoal ..... July 8 43 13.0 4.3 8.9 Shackleford Bank ..... Aug. 7 30 11.0 2.4 7.9 Ft. Alacon Beach, inside ..... Dec. 7 5 7.4 6.1 6.9 Table 7: Seasonal changes in condition of female Emeritas collected on beaches at Beaufort, N.C. (From Pearse, Humm, and Wharton 1942; Table 11). No. with No. with Date eggs small males Total 1940 June 2..... '43 0 292 July 25 ..... 22 0 25 July 28 ..... 103 0 104 July 29 ..... 13 0 13 August 3. @ ... 12 3 16 August -7 ..... 25 11 37 August 16 ..... 61 34 97 August 18 ..... 76 24 105 August I_)O ..... -38 46 SIS August 24 ..... 7 22 32 August 27 ..... 25 27 53 August 30 ..... 14 39 53 December . ..... 0 .0 7 1941 June 28 ..... 33 0 54 December 7 ..... 0 0 17 198 A junges Litoral b C B 10 2 3 rn 40 so h Y__ IZ Y. so. 4 20 M 30 rn altes Litoral KIM Supralijoral SublitOral Jun FCIS (U.81604) M16-S bis Mittelsand 10 M. Slhl@tf 0, E::]SChlamn, u. Ton 30rn Fig. 14: Diagram of changes in the coastal environment during ageing of a coast (A-D). A newly-formed Cliff; b. submerged rock; c. island; d. shingle; e. sandy bay; f. high cliff; g. saddle connecting submerged mountains; h. crag; i. rudimentary sand beach; k. sand bank; 1. disappearing rocky littoral; m. sub- marine mount; n. unbroken cliff line; p. unbroken beach (From Riedl 1966; Fig. 316). 199 High energy beaches vary enormously in their dimensions. The young- est beaches, mainly at the ends of bays in young shorelines, are only a few meters long and broad. They consist of a coarse sand layer, just a few cent- imeters thick, which overlies the rocky surface. Old beaches may reach an unbroken length of a thousand miles and a breadth of several miles, particularly when the vertical coastal angle (between surface and coastal. inclination) is small and an open ocean basin provides long fetch with long swells. The thickness of the sediment bank underneath the shore (Fig. 15)'may reach 8000 feet, as measured between New York and Norfolk, and during the time this layer was piled up, the beach presumably moved 100 km toward the sea. Interstitial space between sand grains is an important aspect of high energy beach systems, and continual sorting due to wave forces prevents it from being infiltrated by finer sediments. Consequently the substratum, although in perpetual motion, is a permanently porous system. In areas of high sediment deposition, however, primary beaches often are cut off from surf stress by the piling up of new offshore banks which build long islands and embay the older primary coastline in sheltered sounds (See Fig. 10). These older coastlines then accumulate fine sediments and turn into madflats and marshes. Yet'as they lose their sandy character, the new high energy beach at the front of the offshore bank develops. The sounds gradually fill through deposition, but although the land area increases, the biological continuity of the beach system remains unbroken. The continuous balance between movement of its particles and stability of its entity is characteristic of a sandy beach. Reduction of mobility destroys the system, as does instability. The system's balance is due to a self-designing interaction between coastal inclination, sand grain sorting, and erosion-transportation-sedimentation relationships. Geomorphology The geomorphological pattern of a sand beach consists of fringing barriers and troughs offshore, a surf slope, and surf terraces whose dimen- sions vary with local tides and wave force. It also includes an extension (underneath coastal dunes) into the coastal groundwater system. A cross section of a beach (Fig. 1.6) shows a series of steps and terraces within three main regions. In the offshore region"bare and troughs are lined up parallel to the coast. These bars, mostly from one to a few feet high, usually remain below water. In some areas they pile up to the low tide level, reaching several miles in length and several hundred yards in breadth (known as "Sande" in the North Sea). In high sediment areas, as already mentioned, they may rise above sea level as fringing offshore banks. They may line the coast, producing long bays and cutting off former high energy beaches from surf stress (locally known as outer banks, "Haff" or "Lido", and as sounds, Neerung" or "Laguna"). The foreshore region often includes several steps or levels varying with the local tidal dimensions and exposure. In going from sea to land.' a low water step with shell and coarser sand and wells of brackish water is encountered, followed by a low tide terrace, characterized by coarse shell 200 0 100 km. New Nk deptdinfe et Ift. C .30 5 M.) 400 N "g, I 6 711 coo Q) 0 0 0 38P 11 it /'(@V66 Depth of crystalline under- d n' Derteurnined from seismic refro Determined from ctions -drillings Water depth 76o 720 Fig. 15: Thickness Of sedimentary banks in the coastal shelf area between New York and Norfolk (After Ewing, from Dietrich 1963; Fig. 13)- -3HOAC 04 SCACH COAST 4=SLOPE of SHOPIC POU LE OCR OCR Urf COASr LINC CREST or beftus 11.0C TCRSACC kNIGH WAT tit LIMC at ACK 3CAAP TAOUGK-j -LO@ @VATEM L HE (3oome.uNt I Fig. 16: Terminology for a beach profile. Berms are small impermanent terraces formed by deposition during calm weather and by erosion during storms (After Shepard, from Kuenen 1950; Fig. 121). 00" LC SCUS'R 'C.AS CRCST or 201 particles, short ripple-msa@ks, and flat ponds at low tide. Next is the high water step, sometimes clearly marked by, long and dense stkpeg of finer shell. Y Next is the high tide terrace, characteristically smothed by the ti@s of high p water waves. Its upper limit is called the berm (Fig. 16). At the first crest of the berm the foreshore @6g'i6n-turns into the backshore region, which may consist of several sharply edged.bei-ms, surfaced with dry sand which end at the foot of a cliff or the first dune with some vegetation. From a vertical view, the offshore-bars show outlet6 kept open by a. strong back or over flov,.and the shoreline is serrated withi@ @everal.scales. On a small (l.to 10 m) s6ale are the beach cusps, sequences of flat embayments, with corresponding shallow submarine deltas,as mirror images'(Fig. 17). On a larger scale, beaches with stronger surf and landward currents show rip- currents (Fig. 18).(Shepexq 1948, Shep .etrd and Inm@i 1950)4 These back' currents locally form strong flows tip to lm/lse6, reaching to 300:m off shore. In form- ing flat caps and deep feeder.afid n@ck channels, they carry,finer s .and far out to deeper waters. These phenoni@na participate in 'permanent sorting o .f the sediment as well as in the dynamics of beach development. Finally, on a microg6ological Scale,, ripple marks are both character.,. istic and important for high energy beaches. As A result of certain (not yet clearly understood) relationships between the s'p6ed.of w .ater particles and the length and rhythm of wave oscillation,.rippl6s are formed (Fig. 19). They v@ry from I to 50 cm. in wavelength, and their heightyaries betwe6n one@third and one-tenth of the length. In shovelling the sand into'long crests, in changing their position and wavelength with every chan' in water m6vement, they contri- ,ge bute strongly to a permanent shifting and sorting in the surface layers. Sedimentology Sedimentology is a master key to differentiation-in the interstitial environment. Much is clarified by simple grandulloMie'trical investigations. However, the problems of hydrodynamics within a porous body is rather compli- cated. The importance of the edaphic structur6 (oi.substrate composition) is based on the fact that it permits prediction of three types of correlations: first,the outer or primary hydrodynamic conditions;.second, the inner or secoxid- ary hydrodynamics within the sediment body; and third (in a preliminary way), the composition of the fauna selected. The following six sediment parameters, in order of their general impor- tance, are of biological significance. (1) The medium grain size (from 0.1 to 4.0 mm mostly) which is correlated with primary input of h5idrodTnamic energy. Mean grain size increases.with energy and influences the absolute pore.size, the maxima of interstitial currents, and the mobility of physical and organic components. (2) The grain size variation (F), expressed in % of the min frac- tion, or in the number of peaks within the grain size curve. Low F expresses high constancy of 6nergy input, a maximim of relative pore volume ind a uni- formity of biological conditions. High F, of course, shows the opposite. The number of peaks is an expression of the variation of energy input and the min features of the inner hydrodynamic and faunistic variability. 202 Fig. 17: Diagram'of beach cusps, with submarine deltas corresponding to the embayments as mirror images (Mainly according to Ti rmans, from Kuenen 1950; Fig. Y 1711 B-C-EA ZO,E@ ."SAC-Cpt ZONE Fig. 1.8: Diagram of a rip current showing components and direction of net water movement. Relative velocity is indicated by length of arrows (After Shepard, from Kuenen 1950; Fig. 122). E @-Z I =E- 203 B > Fig. lg:, Cross-sectional view of ripple marks. A. Symmet- rical oscillation ripple marks; B. asymmetrical oscillation ripple marks; C. symmetrical oscillation ripple marks with rough troughs; D. current ripple (Kuenen 1950; Fig. 129). I I loprn 0.1.. Imrn I.. ldrn Korngr6fta ,nitIlgre Geschwindigkcit io0o in cmisex. Losion WI, 10 Transport Sedimentation Oil Ton Schluff Mehlsand Fein - Mittel - Grobsand Kies Steine Fig. 20: Graph showing influence of particle velocity on the sorting of sediments. Cross hatching shows boundary between erosion and transport zones. Un- broken curve represents boundary between trans- portation and sedimentation zones (After Dietrich, from Riedl 1966; Fig. 314). 204 (3) The contributions of small-size fractions (expressed in % of fine sand, silt, and clay participation). Reflecting the extent of minimum periods of dynamic stress, these minimum fractions reduce dramatically the pore space in a relative as well as in an absolute sense. A small amount of fine sedi- ment often chokes the whole pore system, cuts off ventilation and lifts the deep, anaerobic layer up to the surface (See Fig. 51) (Brafield 1964). (4) The amount of decomposable organic,matter in the sand (given in % of carbon times 1.9 and in % of nitrogen times lb, or in measurement of deterior 'ation of the climate gives a general idea of the input-consumption relationship. This, of course, is of high importance, although methodology and interpretation of data axe still creating arguments. Generally'speaking, the average of around 1% decomposable organic matter decreases with grain size and with distance from the coast (grain size generally decreases with increasing coastal distance). Although the organic amount can reach high percentages (if an organic wrag bed becomes imbeded within sediment layers), under high dynamic input it remains remarkably low. Yet, the amount of food available in a given time not only depends on the storage, but even more on the speed with which nutrients are deposited and decomposed within the system. It is clear that higher hydro- dynamic energies, larger pore space and higher flow-through rates provide chances for speedier energetic loops. (5) Form and_p!@ckin@ of the sediment particles (defined as edged to rounded, and loose to tight) again are correlated with hydrodynamic energies and have strong influence on the pore system. Roundish forms show grinding, and result from packing and shaking activity. Computation of pore space in loosely packed as compared with tightly packed spherical grains (of equal size to make it simple) is based on the relation of the volume of a cube (as' oppose d to that of a pentagonal dodecaeder) to the volume of its inscribed sphere. (6) Finally, the amount of calcarous matter (in %) demonstrates the origin of the sediment. Higher percentages probably offer a buffering system in cases of low pH. Besides these general characteristics of sand composition there is also a rather complicated and dynamic pattern of their interaction. This pattern is three dimensional, varying from capes to bays, with distance from the surf zone, and from the surface to the deeper layers. In sand environments it is characteristic that all these gradients dynamically change with each change in "the hydrodynamic forces. Hydrodynamic conditions must be balanced between erosion, including sorting,and deposition effects. If erosion overbalances sedimentation, the beach disappears. If deposition predominates over sorting and erosion the interstitial space is soon filled and the beach becomes a mud flat. The erosion of silt requires water movement at a rate of about 80 cm/sec (Fig. 20), while medium sand (0.2 - 0.5 mm) loses stability in water moving at the rate of 20 cm/sec. in other words, sand is eroded much more readily than clay. The opposite is true with regard to-rate of sedimentation. Sand settles out at a water speed of only 10 cm/sec while clay remains in suspension until water flow rate is reduced to 0.1 cm/sec or less. 205 The self-balancing effect between erosion and deposition involves four factors: the boundary effect, friction, critical depth, and coastal angle. The boundary layer effect (Fig. 21) is partially responsible for the relative resistivity of fine sediment to erosion. Currents (of liquids or gases) are drastically reduced in speed as they approach solid surfaces, due to friction with these surfaces, and turbulent particle movement becomes laminar. Boundary. layer dimensions along coastlines depend on viscosity of the water, roughness of the bottom surface, and speed, length, and duration of the current, but lies between a few millimeters and a few centimeters. Larger sediment particles, therefore, axe reached by currents of greater speed, while finer particles are relatively protected. Seas with wave heights of one to two meters and a period of 4 to 6 seconds have a particle speed of 80 to 100 cm/sec; a speed of 60 to 80 cm/sec reaches the coast_Both sand and silt go into suspension, but with increasing depth (Fig. 22) the orbital movement of the rotating or oscillating water particles is reduced by friction. At 10 to 20 m, depths particle speeds of 10 cm/sec axe reached, and all sand settles out and is trapped at the coast. Clay, however, remains in suspension and is transported far offshore and down the edge of the continental slope. The permanent balance between erosion, transport, and sedimentation not only guarantees the preservation of the sandy beach environment but also causes high structural diversity. Geologically the result is described as .false bedding, current bedding, and cross bedding. Biologically drastic changes and inversions of the common faunal gradients result. Coarse shell with low organic load, having attracted a brackish groundwater drain, may be covered by strongly reduced fine sediment with high organic contentand so on. Another sand trap within the self design of high energy beaches is based on the laws of critical depth. Seas start to "feel" the bottom at a depth corresponding to wave length (Sverdrup, Johnson, and Fleming 1942). The oscill- ation space of the orbital movement of waves becomes narrowed, making the seas slower and steeper, and bending the wave crests toward the beach front. At a depth of about a half wave length the energy input toward the bottom becomes biologically important. This outer boundary of reduced oscillation space is called the second critical depth and lies at 100 m. (Figs. 22 and 23). In this oscillating body of water sandy bottoms appear, characterized by-rigorous sorting, removal of fine sediments, and formation of long ripple marks. The upper limit of ine sand biota depends on tide dimension and local wave ener- gies. It often reaches 4 and sometimes 8 m. above midwater level. Within the reduced oscillation space and with decreasing depth the speed of the waves decreases and their height increases until the front of the seas becomes too steep for harmonious oscillation, and breakers are formed. This happens at a depth which corresponds to about 2-5 times wave height, the first critical depth (Figs. 22 and 23)- In the breaker zone aremarkable.amount of wave energy is consumed in counteraction of turbulent water forces. Not the original forces but "residual waves" (translation waves) finally reach the land. The amount of energy reaching the surf slope and the surf terraces, howeverp depends on the vertical coastal angle. The steeper it is, the nearer.is the first critical depth to the waterline and the greater is the proportion of the 206 Surf3ce of W3ter Velocity Fig. 21: Schematic section of a current, showing distribution of velocity and turbulence. The boundary layer is repre- sented by the straight arrow region. Larger particles on the bottom are influenced by Turbulent greater velocity than small particles (From Kuenen 1950; Fig. 117). Lanninar '20M Hohe obare Wallanschlag - Grenza Auflautht5he aubere Brandungszone Hohe der Ausgangswalle .10 Ruhawasserspiegal .5 ....... ....... ......... ........ ..... .2 AA.-O ............. ............. ..................... 2 0. 3' @;nere Br3ndungszone k 4 l.kritische Tiefe Schwin Ungsz 10 15 N 5n, 20 lorn 12" -25 2. kritische Tiefe 30 StromunpZone .40 10 M\\ 5m 0.; .50 SO rn Titie 200 150 100 so 6.0 20 1) 510 GeSChwindigkeit in CmISek. 1 Z5 Fig. 22: Graph showing decrease in particle velocity in the. sublittoral according to wave action and current. The coordinates are particle speed and depth. Solid lines show speed reduction (cm/sec) with increase in wave height W. stippled area shows the average condition (From Riedl 1966; Fig. 317). 207 Brandungs- verengter raum Schwingungsraum 2.Grundber6hrung 1. GrundberUhrung (2.5 H) M12) 0 0 A N cz, Z) 0 0 0 0 0 0 0 Fig. 23A: Diagram showing transformation of the orbital movement of particles with respect to depth and distance from the bottom. The two arrows indicate critical depths: first critical depth at 2.5 wave height and second critical depth at 1/2 wave height (From Riedl 1966; Fig. 212). II11TI1 11 1! llfli:1!11111 I Fig. 23B: Diagram showing energy consumption in the breaker zone (After Davis, from Kuenen 1950; Fig. 54). 208 original forces that reach the beach. Ifnow, erosion at the water's edge occurs, sand is displaced there, but deposition increases in the outer oscillation zone, the vertical coastal angle decreases, the second critical depth moves farther offshore, the residual waves lose energy, and the system becomes balanced again. If particle speed during the maxima of local surf beat reaches 100 cm/sec all sand fractions go into suspension. A drop to 50 cm/sec immediately re- leases gravel, and a drop to 20 cm/sec releases coarse sand. Finer fractions settle out at speeds between 5 and I cm/sec, contributing to further decrease in vertical coastal angle. On the other hand, high local particle speeds erode deep bays in the beach front. The deeper they are, the smaller the horizontal coastal angle becomes (angle of open sea, seen from a point at the shore), and the smaller are the chances of being reached by seas from many directions. As the exposure index decreases, so does the vertical coastal angle. The opposite is true for sheltered bays. They soon fill in and are incorporated into straight beach fronts. Extremely long, smoothly bending beach lines axe the result of the continued action of these self designing mechanisms. Amount of sediment production and distance of sediment transport axe also important for beach formation. There are four major sources of sediment: rocky shores, benthos communities, landslides, and plankton commmities; and three major types of sediment: boulders (or cobble), sands, and clays (Fig. 24A). Erosion on rocky shores produces mainly boulders, cobble, and gravel, but sand is also produced in fair a=unts. Greater contributions to beaches are made by calcareous benthic biota: shell beds and algal and coral reefs. The par- ticipation of boring animals and the chewing activity of errant benthic macro- fauna can be enormous in the decomposition of reefs and in grinding shell and coarse sand fractions into finer sands. Plankton shells produce mainly oozy fractions without much additional erosion. Terrestrial erosion, transported mainly by rivers but partly by storms, contributes mostly sandy fractions, but also clay. In a 10 m deep water body (average for a beach environment) coarse material, cobble and gravel settle in seconds (Fig. 24B) and are deposited near their source. Sand usually takes less than a minute (10 to 60 sec) and remains in the surf area. Because of the balance between erosion and deposition and the prevailing currents parallel to the coast, sand is shifted along' the shoreline. Silt and clay requirefrom an hour up to 1-5 months to settle in the same 10 m, and may be transported very far into deeper waters. Sediment derived from the land decreases from large continents to small oceanic islands, but reefs and calcareous benthic conmini ies increase from cold to tropical waters. For these reasons, continental shores in cold-temperate climates contain only quartz grains while tropical waters are surrounded by fairly pure calcareous sands. In more stable situations the contribution of the macrofauna to sand structure-becomes observable (Fig. 25). The "rake structures" CINFulagefuge", Schaefer 1962) of raking and digging animals are very specific, and when in large numbers these animals strongly influence a layered substratum. Further- 209 Schlarnm g s c h 6 t z t Sand Feis\ Off e x P o M e r t Ger6II - 4 Sand - Schtarnm - TranSport Fi-. 24A: Diagram of sediment production and transPortition. 9 I. Shore contribu@i6n; II. benthos contribution' III land contribution, IV.,plankton contribution. Striped arrows represent stone, stippled areas sand, and white arrows clay (From Riedl 1966; Fig. 315)- Yzv FALLVELWIT 10 CWSEC Fig. 24B: Graph showing fall velocity of que!xtz-density grains oflaverage natural shape at 200C (From Bagnold 1963; Fig. I). 210 M k., Fig. 25: Diagrams showing the influence of digging organisms on sediment layering. A. The small crab Corzstes. B. The heart urchin Echino- cardium (From Schaefer 1956; Fig. 16T_ 211 more, over long time,periods the chewing of the sediments by many types of the macrofauna (the "organic mill") causes a decrease of grain size in deeper and older layers. Rghest particle m6bility ib demonstrated by coarse shell within the surf zone. During the incoming tide this material is collected and transported to the high tide mark., During outgoing tide it.is washed back or remains partly scattered over the whole tidal zone. This happens so rhythmically, that,for some species of Turbellaria, it serves as a permanent lift, holding them in the high energy area (Rieger and ott 1969). Lowest particle mobility is related to the deepest sand layers, where influence of terrestrial soil occurs, or the marine sediment itself turns into subfossil conditions. Interstitial Climatology Interstitial climatology offers both static and dynamic aspects. Since measuring currents in the pore space is still a problem, investigations of parastatic gradients have.been preferred, and dynamic explanations have been generally derived. Eleven partly correlated parameters of interstitial Cli- matology should be taken into consideration (Figs. 26 and 27). (1) Temperature strongly varies in surface layers, due to evaporation and to heat storage in dry sand under summer radiation. It is low and most stable in the groundwater horizon. (2) Water saturation changes betwee3i groundwater and surface levels. (3) The same is true-for salinityp but there is also a gradient.between the marine and the limnic groundwater, producing a zone of brackish water between. (4) Oxygen availability is relatively highin the moist supralittoral zone, but it drops drastically within the deeper layers. Hedgpeth (1951b) points out that "an almost universal characteristic of sandy beaches is the dark or black layer in the region of stagnation and oxygen deficiency resulting from the formation of ferrous sulfides under reducing or anaerobic conditions." The study of this anaerobic stratum, however,'has only recently begun. Its depth beneath the surface is related both to wave action and to the interstitial space of the porous system and ranges from a few feet in coarse sand and shell subject to heavy surf.to a few millim6ters,in more protected areas with . mostly fine sand (See Fig. 51B). As Hedgpeth says, "Since the formation of ferrous sulfide in sand is a phenomenon of significance in general problems ... it is unfortunate that it has not been studied in more detail". (See Bruce i928b, Pennak 1951, Perkins 1957, Gordon 1960, Brafield 1964, Riedl 1969, Fenchel 1969).. (5) @ree C02 levels rise remarkably in some shore layers. (6) Water hardness -W-777 T_ has been observed to increase with distance from the coast, along th a slight drop in pH. Less information is available,with regard to (8) gradients of decomposable organic matter, but there is evidence enough to predict remark- ably strong differences. '(9) Redox potential'and (10) H2S concentration have been measured only very recently, since thedeeper anaerobic layer,has remained nearly untouched. (11) Light is very limited in its distribution within the sandy beach system. Although high energy beaches generally are subject to strong radiation, light is cut.off completely within the first surface layer. The thickness of this layer varies with the transparency of the sand and de- creases i-rith grain size from a few centimeters to less than one millimeter. Rhythmical variations in the pattern of these parameters are caused by tidal, circadian, and seasonal changes in the outer climate. Tides influence otl w (D 0) td tj Vh P. m 0 ts 04 0 b m w C4 (D -@-& & U. U. C) -- --3 f-: 0 (D P)0 Fj M' (,D P) (D c+ C+ P. m P, 0 (D 0 ON @,o M ts --tk @- ; m 0) C+ 0 W 0 x 0m C+ m F4 0 F4 :30 C+ C+ m C+ 0 m -4 CD t3l a C+ P) :zz (D inj t-4 Fa m C+ N$Ci. o"m F"'. Ist C+w 9 f, in m 0 Fj C+ (D m C). C) -0 C@ 0 ip co rn Ln ..5-- A Fj0 ro (n 0 Ln .74 ORD Im :E y w C) C) % C, I;uHP, (D P) F-1- E7j CD F, 011- (D F-6 F4 FJ c+ D' IS C14 r_ @-4 C- 1@ P',0 ts0 0t-t 0) (D Llqj Km A C) Zn C) pC+. C3 0(D LA @v @j oq 0 Ff C),\ C+ F4 C+ C4 213 the system by causing movement of the whole subcoastal water body governing most of the parameters. Circadian rhythms affect surface temperature and . salinity,mostly. Seasonal changes involve variation in radiation, precipitation, surface salinity, and temperature. They also influence the height of the ground water level and the position of the brackish water cushion. The dynamics of the interstitial waters'are to be understood in terms of three factorsall of which fill and drain the system in different rhythms. First, the sea between low tide mark and'the first crest, with changing water levels and wave tongues acting at different heights. Second, evaporation and precipitation of-marine spray or rain water over the whole surface. Third, seasonal changes in groundwater input from the land side, affecting the deeper layers. Five different water bodies can be differentiated in a qpmplete high energy beach system (Fig. 28): a w ine zone of permanent sediment displace- ment (transfer zone), a brackish mixing zone, a marine circulation zone, a mist sand (pecolation) zone, and a nearly fresh groundwater zone'. BIOLOGICAL ASPECTS In physical respects sandy beaches have much in common with sandy deserts, yet their biota are very different. Until the 1920's the sand environment of the coast,was considered to be the "marine desert" and remained biologically neglected until Remane (1933a) started investigations of the sandy 'coasts of Germany in the hope that the supposed impoverished biota there might offer fewer investigational difficulties than desert life. Since that time "psa logy or sand biology has become strongly developed, first in Europe and more recently in the United States. Today sand is known to be one of the richest and most challenging of 7w ine environments, where thousands of highly adapted species have been discovered, where all invertebrate phyla are represented, and where the most unexpected problems concerning food sources, dynamics, and energy flows have arisen and axe still largely unsolved. Major Biota The high energy beach system, as already mentioned, offers space for three main types of populations in contrast to most other b16topes which offer only two. In addition to providing space for epi- and endofauna, (animals living on and in the substratum) porous systems give a third opportunity; space is also provided for, a mesofauna, living within the interstices. The epipsa In The epipsammon (Psammon, Greek for sand) contain species living on or above the sand surface. In a number@ of species, it is the least important link in these stratified groups. It contains a relatively small representation of the animal kingdom, but it is the only group which links marine and terres- trial species. Fishes.and birds, as well as certain beetles, are in the group. The small representation is to be understood in terms of three facts: first, sand as a movable substratum is inhospitable to many types of organisms needing- stable conditions or concealment; second, sand as a semi-liquid environnent Z 0 rl E D rtC99AC ZONE DE CirtCULAT10h TALUS BE TPLAMSPERT ZONE BE PEPCOLATION MOPPE SOUTERRAME COrITIMPTALE DOUCE ZOMI DE MELANGE Fig. 28: Diagram showing circulation of water in a sea without tides. Zone of Ressac is the foreshor@e area; closely stippled area is the circulation zone; black areas represent the transfer slope and zone of percolation; sparser stippling shows the mixing zone; long arrows indicate the sub- terranean continental groundwater area (From Delamare 1960; Fig. 6). 215 attracts endofaunal species of epifaunal origin which dig into the sand where they gain more stability as well as protection; third, it is usually the larger'forms (macrofauna) that are strong and speedy enough to keep up with wave action (there is no foothold as on rocky shores for such animals as limpets, barnacles, or sea anemones), and these larger forms, the last link in the food chain, are always relatively few. Although many fishes, birds, and beetles can be observed along shores (for example, 170 kinds of shore birds are listed for North America by Bent, 1927, 1929,)only a few are restricted to the high energy beach system. The sanderling (Crocethia alba) can be used as an example. This shore bird obtains 11 most of its food by probing in the wet sand ... or by picking up what is washed up and left by the receding iraves" (Bent 1927, 1929). Analogous fishes are representatives of Millidae, probing the sand with their barbels. The tiger beetle (Cicindela dorsalis) can also be used as an example of organisms which are most often found on high energy beaches. Adaptation to epipsammal life does not include obvious structural specialities, except barbels, and fish types bearing baxbels are known from many different environments. Behavioral adaptations, on the other hand, are clear. Trophically, all types of epipsammon are animals adapted to collecting the endopsammon or their cadavers washed out of the sand or brought from the ocean, mainly in the,meiofauna-size range (organisms of nedium size). The endopsaxmon The endopsammon contain species which burrow in the sand but are too large to use the interstitial spaces (Fig..2). This includes macro- and meiofauna. They build permanent burrows lined with stabilizing mixtures of secretion and fine sediment. When displaced, they hasten over the sand surface (cumaceans and mny crabs) and disappear surprisingly quickly into the sand in a chosen place. In this respect they overlap with the epifauna. Members of the Rajidae, Soleidae and Uranoscopidae (rays, tonguefishes and stargazers) hide in the sand but feed on epipsanmon macrofauna. Similarly, species such as mysids and male cumaceans rise at night to the surface but feed on bottom detritus or graze on sand grains. The endopsammon boundaxy can be drawn to include species, most of whose biological activities are restricted within the sand. There is a much wider species representation in the endo- than in the epifauna, but it is far below that of the me6opsammon, especially on the high energy beach in its restricted sense. In locations of greatest wave stress, the endofauna is relatively limited to robust and quickly moving types (such as crabs); stationary or semi-sedentary types are absent. On the contrary, in more sheltered areas, stationary species (lancelets) or semisedentary types (seafeathers, sedentary polychaetes) are found. At least some of these types axe not very sensitive to fine sediment accumulation. They even appeax in biotopes where the interstitial space has vanished, leaving little in co n with high energy beaches. The representative endopsannon groups are mainly higher crustaceans;, some molluscs and a few polychaetes and echinoderms are also typically rep- resented. Among polychaetes, eunicids (Staurohereis), maidanids (Pletaloproctus) and arenicolids (Arenicola) are represented, but mostly in extension of their main area on somewhat more sheltered shores. Of the amphipods, haustoriids (Haustoria) and talitrids (Orchestia, Talorchestia) may be abundant; among 216 idotheids (Chiridotea) and among cumaceans, several families are common. Stomatopods are represented by Lysiosquilla. Decapods are more, strongly represented. A few shrimps (Ogyris), thalassinids (Callianassa), albuneids (Lepidopa) and portunids (Arenarius), but particularly hippids (Emerita) and ghost crabs (Ocypode) are highly characteristic. Of the rest, ,some gastropods (Oliva, Terebra) are regularly present, and a few bivalves (Donax Cardium) are typical of high energy beaches. Finally, among echinoderms, the sand dollar (Ivbllita) is a characteristic representative. Adaptations are very distinct in several species, and their functions differ so greatly from those in the mesofauna, that they make differentiation between the two types reasonable. @bst striking are adaptations with respect to shape and locomotion in species living in the surf beat. Emerita disappears beneath the surface in a fraction of a second. Djjonax (even more surprising because a member of awkward bivalves), disappears in about a second. This unusual burreving ability is due to adaptation of the legs in the first case (Fig. 29) ana of the foot in the second. Coloration also can be an adaptation: the light sandy color without any pattern, as in the ghost crab (Ocypode), the beach "flea" (Talorchestia, an isopod), in Emerita, in Ogyris and others. Also eyes may be small (as in Emerita) and sensory bristles or tentacles very long and abundant (PL-arse, Mum and Wharton 1942). During the breeding season, Emeritas have males attached to females and burrowing shrimp consort in pairs (Se.; _@ble 7). This insures fertilization in the shifting environment. Trophically the endopsammon do not contribute any primary producers to the system. No higher algae are represented in the high energy area, except for de*tached material stored as wrack beds on the shore, because of lack of substratum stability. The animals are mainly carnivores and herbivores. Some collect dead animals or feed in wracks, but even more important are the many types of suspension- or plankton-feeders. They range from hunter types, waiting in their burrows, through Emerita, filtering the back-flow of waves with its antennae, to highly specialized filter feeders such as lamellibranchs. 'The mesopsammon The mesopsammon have by far the greatest diversity of all psammon types, each beach system containing more than a thousand species, compared with several dozens in the epi- and endopsammon together. They also populate a three- dimensional environment, with microfauna having the greatest density (the macro- fauna remain in surface contact and have a much lower density). Finally, the mesopsanmon are highly sensitive to the slightest changes in edaphic conditions, which correspond exactly to differences in the overall hydrodynamic forces. Other psammobionts correspond in a much coarser fashion. Therefore psammologists often take only the mesopsammon into consideration when they talk about the sand biotope, and certain it is that mesopsammon axe a most important and challenging subsystem. Faunal representation, adaptations, and trophic relation- ships will be analyzed. @bst surprising is the fact that representatives of nearly all main groups of the invertebrates have been able to adapt to the interstitial environ- 217 FIPt5T LEq V LE9 Fig., 29: Diagrams showing resting ell position of Emerita talpoid in the sand and movement of UROP" the appendages while burrowing. Solid arrows indicate power and dotted arrows, recovery FORTH LEq (From Pearse, Humm, and Wharton 1942; Fig. 22). 1 MM. A B Fig. 30: Body shape in the genus Halammohydra. A. H. schulzei Remane; B. H. bctopodides Remane; C. H. vermiformes Swedmrk and Teissier From Swedmark 1964; Fig- 3)- 218 ment. Only a few groups have not: Porifera, Ctenophora, Scaphopoda, Cephalopoda, Decapoda, Hemichordata, all enchinoderms except h6lothurians, and finally Chaetognathb and Acrania. Problems of body structures, locomotion and trophic adaptation may have created insurmountable difficulties for these forms. However, interstitial ascidians and bryozoans, for example, have surmounted problems of body size as well as of locomotion in very unexpected ways, so representatives of some of these so far undiscovered groups may yet be found among the mesopsammon. Among the many invertebrate groups represented, there are some nearly completely restricted to the interstitial environment. These are the phyla Gnathostomulida, Tardigrada and Gastrotricha, the orders and suborders Schizorhynchia, Archiannelida, Mystacocarida, Acochlidiacea and Actinulida .and aberrant types of other groups such as the YBdreporaxia, Polychaeta, Bryozoa, Brachyopoda, Holothuroidea and Ascidiacea. The systematic rank of restricted groups can be used'as the measure of the age of their biotope. Without fossil documentation in a relative scale, we mast assume that ancestors of systematic groups have to be stepwise ol(@er the higher their category in the classification hierarchy. Furthermore, we have evidence that larger groups have originated in their restricted environ nt (Riedl 1966). The very high rank of restricted psa n groups therefore lets us assume a very old age for the psammon biotope. As a matter of fact, only two other biotopes have restricted systematic groups of compaxable rank: the pelagic and the pelos (muddy bottoms). Obviously, the sandy beach is one of the oldest biotopes on this planet. The dominant groups in the mesopsammon are diatoms, ciliates, turbellarians, gnathostom.xlids, gastrotrichs, nematodes, and harpacticids (group of copepodes). The total groups represented number about twenty-three (a to w). Algae (a) axe mainly represented by diatoms and bluegreen algae as well as by bacteria. Fungi (b) in the sand habitat have been described most recently (Kohlmeyer 1966). Protozoa (c) are very common, mainly long and slender ciliates as well as for- aminifera attached in some cases to sand grains (Dragesco 1960, Rhumbler 1938). Coelenterates (d) are represented by several small, highly adapted groups, mostly belonging to class Hydrozoa with dwarf polyps or extremely reduced medusae, such as Othohydra, Halammohydra (Fig. 30), and Armorhydra; but micro- scopic representatives of classes Anthozoa and Scyphozoa have also been dis- covered. In the first case it is a bipolar madreporarian (Rossi 1961), in the latter a reduced stauromedusae (Salvini-Plawen 1966). Turbellaria (e) are common, most typically represented by Otoplanidae (Ax 1956a, a group of Proseriata) and Schizorhynchia (Karling 1961, a group of Kalyptorhynchia). But also Acoela, Yacrostomida, a new suborder of Catenulida @ not yet published) and others are included. Gnathostomulida (f) a new phylum Ax 1956b) is typical of mesopsanmn, with more than 40 species and 10 genera already known (Fig- 31) (Sterrer 1968, Riedl 1969). Rotatoria (g) are less common but are represented (Remane,1933b). Gastrotricha (h) are extremely abundant members of the interstitial psammon, and in marine environments they are nearly restricted to sand. Considered eaxlier as aberrant types (Re 1925), these strange forms (Fig. 32) are known today to constitute one of the main types in the sand environment (Wilke 1954). Nematodes (i) compose the Ir Ir f sernaeog th,la Nanqgnathia, exigua M,6 en i -On c@ nathia G. 0 1111f ra nigrostorna G. J Gnathostomula, brunidens microstyla Labidognathi Ptero - longicollis, jennen 9nath'(a. Austrognathia ata lyra arm kirsteueri P. 200PM Mediocristata P A017- 0enitera -.rosacep %10 Fig. 31: Gnathostomaida, shoving species knovn from-the east coast of the United States (From Riedl 1969; Fig..2). 220 v (3) (4) (S) Fig. 32: Gastrotricha. Order Chaetonotoidea, Chaetonotus dis2m Wilke; (@T5) Or-der Macrodasyoidea; (2) Urodasys viviparus Wilke; (3) @seudostomella voscovita Swedmark; 4) Umas- ioderma heideri Remane; (5)'Diplodasys ankeli Wilke. TFT Diagrams (2) ahd (5) modified after Wilke rom Swedmark 1964; Fig. 7). OR5@ S Az 50 Fig. 33i Nematalycus nematoides, an interstitial mite (From Delamare 1960; Fig. 103). 221 largest fraction within the microfauna, as is true in nearly any environment (Wieser 1959)- Kinorhynchs (j))generally common in fine sediments,,are represented in the interstitial environment by the new suborder Heterorhaga (Gerlach 1956). The Nemertini (k) are represented by the systematically isolated Ototyphlo- nemertini. Several unexpected types of archiannelids (1) are also typical of the mesopsammon and axe neaxly restricted to high energy beaches. Some of them axe the smallest annelids known (350/ilong). The large group of polychaetes (M) mostly consists of very small species of syllides and other families adapted to the pore system (Swedmark 1958). A remarkable number of 03.igochaete species (n) axe known from the interstitial, coastal environmenty Yet without special adaptations (Buloi,, 1957). Crustacea (o) in the porous system are represented by six groups. First, Copepoda axe present mainly_in the form of harpacticids, often very slender types (Noodt 1952 and 1957). Second, Ostracoda also, but to a smaller extent, show elongation in their interstitial representatives. Third, Yustacocarida, a more recently discovered small group of conservative crustaceans, are strongly restricted to the sand environment (Delamare Deboutteville 1960). Fourth, among the Syncaridae, the Bathynellacea are found, particularly in tropical coasts. Fifth, Isopoda, which normally consist of larger species, in the sand Microparasellidae and Microcerberidae are very slender types, 0.8 to 1.5 mm long. Sixth, Amphipoda, very common in other bottom biotopes, show up in the inter- stitial space as microscopic Ingolfiellidea. Tardigrada (p), mostly limnobiotic, in the marine environment are mostly restricted to interstitial life. Although among,the smallest of metazoans they show most peculiar structure (See Fig. 4), particularly on tropical beaches (Rene.ud-Debyser 1963) - Mite's (q) axe represented by relatively conservative marine groups such as Halacaridae as well as by very specialized types such as Nematalycidae (Fig. 33s I-trenzke 1954). Small terrestrial anthropods (r) such as palpigrades or collembola are known (monniot 1966, Delamexe 1956) from the sand pore system. @Iollusca (s) have three main groups in the system. Solenogasters, known mostly from muddy bottoms have been discovered as very small species in the sand. The same is true for Placophora, until recently known only from stable substrate (Swedmark, Salvini-Plawen, unpublished). Gastropods are represented by strongly reduced groups such as the Rhodopidae, Pseudovermis and Microhedylidae. Brachiopoda (t) were very recently discovered (Swedmark 1967) in the sand: a very small species of the new genus Gwyni (Fig. 3W- Bryozoa M are known to be present as the very curious solitary and migrating form Monobryozoon (Fig. 35A; Remane 1938). Echinodernata (v) are represented only by some holothurians, very small species such as Leptosynapta. Finally, Ascidiacea M are known, with an increasing number of species. All are nearly microscopical and solitary types with rhizoid threads deriving from different taxonomic groups of ascidians (Fig. 35 B.C. manniot 1965)- 222 Fig. 34: Sedentary interstitial organisms. A. Two specimens of Gwynia capsula (Jeffreys), a brachiopod with brood protection, living within a serpulid shell fragment (From Swedmark 1967; Fig. 1.). B. The foraminiferan Discammina fallax Lacroix attached to the surface of a sand gral-n@Aft@er@e-mane, from Delamare 1960; Fig. 61). Fig. 35: Interstitial organisms. A. Monobryozoon ambulans Remane, an interstitial bryozoan (After Remane). Band C. Interstitial ascidians, Psanwstyela delamarei (Weinstein) and PolycarM 4ntarhiza Monniot, respectively (After Weinstein and Monniot) (From Ax 1966; Fig. 11). 223 Adaptations and Species Selection Structural adaptations Structural adaptations, of course, or preselections, at least, are in- dispensable for living in the interstitial environment. Body size is the first unavoidable restriction. Groups with extreme 'ly small size such as gastrotrichs or tardigrades have no problems, and forms of extremely slender shape, such as nematodes, are practically preselected. Others, however, show most interesting reactions to this r1gorous size test. It is not so astonishing that turbellaxians adapt to such conditions. It is more so with regard to gastropods or higher crustaceans. But it is most un- expected to see such types as solitary ascidians or holothurians reduced to dwarf shapes that fit into the system. One of the chances for larger animals to fit into the poJre spaces is to take the "vermiforme" shape. This is particularly applicable to groups anatomically disposed to stretching (Figs. 3 and 4; Remane 1952). But groups without such an obvious predisposition such as isopods or amphipods, harpacticoids, gastropods or mites show to a less extreme extent the sayn ability. Clearly, other forms, such as the ostracods or brachiopods, do not join this channel of adaptation. In addition to the vermiform channel, the "leaf-shape" also gives new opportunities for interstitial dwelling for two types: (1) 'A few sedentary forms (for example, certain Foraminifera) have this shape which permits tight attachment to sand grains and hence protection against grinding and shifting sand. This shape also aids in keeping the necessary interstitial space open in the packed sediment. (2) @bsopsanmon living in the moist zone, where the sand grains are covered with a thin water film, are also disposed toward such adapt- ation. These include mainly very small representatives of the mesozoa, the gastrotrichs (Chaetonotoidea) and tardigrades. Formation of a tail in half a dozen of the groups composing the meso- psammon illustrates typical adaptive convergence (Fig. 4). The advantage of such a tail is related to that of adhesive organs and locomotion in the movable sub- stratum. A contractile tail increases the locomotion-radius of an organism remarkably when it is still anchored by its caudal tip to a sand grain; quick, retraction allows it to escape from a danger spot discovered with the anterior end, to a,protective distance (Wilke 1954, Ax 1963). However, this organ may also be just a product of the process of diminution, as in ciliates or certain acoelous turbellarians which have adhesive organs. The first advantage, then, relates to locomotory stabilization, the final benefit may come in conjunction with the development of adhesive organs. This development of adhesive organs is an important contribution to life in high energy beaches. It is nearly in- dispensable for organisms living in the surface sand in the surf area. These organs are always present in gastrotrichs and gnathostomulids and in most turbellarians and tardigrades. In some turbellarians they have a striking similarity to ones known from gastrotrichs and have therefore become an often quoted example of convergence in the interstitial environment. Yet they axe too small. for proof of their possible structural identity to be obtained with the light microscope, and their ultrastructure is still unknown. 224 Locomotory adaptations Besides size and general shape, locomotion becomes a restricting feature in a sand environment. Nearly without exception, interstitial creatures are vagile or at least have become semivagile through adaptation. Locomotion of the primarily vagile groups is more or less the s as in other environments: nonciliary gliding as in bluegreen algae; ciliary gliding as in ciliates, tur- bellarians, hydroids, gastropods (Fig- 36) and others; snakelike writhing as in nematodes and; crawling as in tardigrades and crustaceans. The adaptation of such primarily sedentary types as bryozoan and ascidian merits more attention. In both cases the semivagile types bear rootlike structures (See Fig. 35). In bryozoans these structures, used for anchoring and locomotion are reminicent of the common stolons connecting specimens within colonies. In ascidians they are used for anchoring (locomotion is due to body contractions) and are also normally common in solitary species. In these large original forms, however, they are tiny compared with the body size; in interstitial dwarf forms, on the contrary, they are often longer than the body length. Nonvagile forms within the sand biotope are chiefly algae, foraminifera and brachiopods. No details are known at present about small incrusting algae on sand grains. However, the incrusting foraminiferan and the sedentary brachiopod have been studied (Fig. 34). The sedentary life of the algae and foraminifera might be understood in terms of their rapid life cycles; the brachiopod appears in coarse material, and has a tendency to hide in the concave parts of shell particles (Swedmark 1967)- Sensory adaptations Finally the sensory systems of the mesopsammon show specialization. Forms bearing eyes are very scarce (gastrotrichs),and in some interstitial groups such as Gnathostomulida or Otoplanidae they are lacking completely. On the other hand, statocysts, sensory cilia, or sensory bristles are very common, often very long or very regularly arranged (examples are otoplanides, gnathostomulides, and tardigrades.) Reproductory adaptations Reproductory adaptations are also known. The first involves sex cells and sperm transmission. The number of eggs produced by the mesops n is generally small, probably due to lack of space. The number may be drastically reduced to one ripe egg at a time (as in some gnathostonulids, isopods, and others). Also copulation predominates over simple release of sperms. Finally spermatophore production is more common than in other marine environments. Within the mesopsax=n spermatophores are known in species of gastrotrichs, axchiannelids, polychaetes, and gastropods (Acochlidiacea). These structures increase chances of fertilization, and avoid the loss of released ga tes (probably a strong possibility in the three dimensional porous system). Vivipaxity and brood protectionalso remarkably developed in the meso- psanmon,*obviously.lead to the s goal. Some groups such as isopods and amphipods already had brood protection before conquering the interstitial environment. Brood protection is also found in Otohydra (hydroid), in Nerilla and other archiannelids -TRN-s-fxotrichs). But- @st ,,and viviparity in Urodas 225 b d F k Fig. 36: Diagrammtic representation of locomot.ory progression of Unela odhneri (Delamare) between two grains of sand. a. b. c'. k.-Stages from contraction to full extension; d.e.f.g. progression between sand grains; i.j. per- istalsis of visceral sac (From Delamare 1960; Fig. 55)- 226 striking is the brood protection mechanisms of interstitial ascidians and in Q3gnia (brachyopod) whose embryos, designed to become pelagic larvae, are kept until'a more advanced stage of development (Swedmark 1967, monniot 1965)- The maintenance of species w-ith low reproductive rates is made more certain with these adaptations. They also increase the chances of remaining in the biotope. The tendencies toward benthic types of larvaej toward thigmotactic' larval behavior and toward neoteny (maturity at an earlier stage of develop- ment)lead to similar ends (Fig. 37). In addition, neoteny aliso leads to diminution, which is important in this environment. The high percentage of. groups without pelagic stages is remarkable: bluegreen algae, turbellarans, gastrotrichs, gnathostomulids, nematodes, tardigrades, isopods, amphipods and others. Only a small minority of species such as gastropods and archiannelides have free larvae. But they also tend to have the first part of their development protected within cocoons, and the hatched larvae are either reduced or they demonstrate no positive phototaxis and therefore no tendency to leave the substratum. Behavioral adaptations 'Gregariousness, or the tendency of specimens of a population to aggregate, has been observed in axchiannelids (Boaden 1963, Gray 1966) and gnathosto- mulids (Riedl 1969). The function of gregariousness is to keep groups of the population in closer contact, a tendency which, particularly within the porous system and in less dominant species, might be of biological importance. Thigmo- taxis and positive geotaxis, the tendencies to stay in contact with the sub- stratum and to orient toward the direction of gravity, are generally co n in all interstitial groups. Some groups (Acoela and Gnathostomlida), if kept in a petri dish without sand, move ceaselessly for hours, seemingly Liearching for a hollow leading downward until they finally die. The mortality rate is also much higher in many interstitial groups if they are kept without substratum (Riedl, unpublished), a phenomenon which merits detailed study. Physiological adaptations Physiological restriction to areas.of high oxygen tension is obvious in some groups of turbellarians (Otoplanidae) and gastrotrichs. However, the observations are based only on emigration behavior and wrtality rates during deterioration of the microclimate. Some information on adaptation to lack of oxygen in gnathostomulids (Riedl 1969), some turbellarians (Catenulida), and bluegreen algae can be derived from observing their zonation in the sediments. Closer investigations, however, are desirable. Trophic Relationships The trophic situation within the mesopsa n subsystem is characterized by low primary productivity, a small number of filterers, a large number of highly diverse so-called detritus feeders, a limited selection of diatom-feeders and predator types, and an important contribution of decomposers. 227 A 0 Fig. 37: Neotenic forms of archiannelid adults. a. Trilobodrilus heideri Remane; b. Diurodrilus mininus; c. Nerillidium gracile; d-e. Protodrilus TTf7t-er Remanes from Delamae 1960; Fig.. 50). 228 Autotrophs Autotrophic or primary production is restricted to the first milli- meters of sand surface and is due mainly to the activity of some bluegreen algae and diatoms. They can be brought to deeper layers, through the move- ment of the substratum, but cut off from sun energy, there is no assimilation in these layers. Therefore mixing of'the top layers with deeper strata does not increase productivity but only food distribution. Recently other strata of (mainly) bluegreen algae have been found within the deeper, o.Vgen deficient, "black layer" (Riedl, unpublished). As yet, the contribution of these saprophytic groups to the system has not been studied. Filter feeders Filter feeders which channel suspended food directly to the system are strongly restricted in the interstitial.environment. Only Ibnobryozoon (bryozoan) and Gwynia (brachiopod), rare species, clearly belong to this group. This is strange because of the high wave energy, providing for transportation of suspended matter. However, the strong reduction in current within the porous structure, as well as the very restricted space conditions there might not allow a greater contribution of this very successful. ecological group. Detritus feeders So called "detritus feeders" are, by fox, the most co n group. The species of all key groups of the mesopsa n, with the exception, perhaps, of the nematodes belong to it. This huge ecological group has been divided (By Remahe 1933a) into four subtypes, based on mechanics of food uptake: Browsers (gnathostomulides, archiannelids, harpacticoids, ostracods, molluscs), pumpsuckers (iurbellarians, gastrotrichs, many nematodes, some polychaetes), pun6ture-suckers (tardigrades), and sand-lickers (cumaceans, certain amphipods) mostly belonging to the endofauna. Without any doubt, detritus feeders form the strongest and in a sense the primary link in the food chain of the mesofaunal subsystem. Therefore a strong inflow of-"detrit-Us" ': formihg,the basic energy sources for a majority of inter- stitial life can be hssil d. However, "detritus" and"detritus feeders" are vague conceptions and often (due to an alfhott complete lack of knowledge concerning the biology of most of the species) a group is labelled as detritus feeding only because of absence of formed food particles in the gut as observed with light microscopy. They may be feeding,on small bacterians, sucking on"bluegreen algae, or collecting dissolved organic matter. This problem becomes pbrticulaxly challenging since the key groups which are nearly restricted to mesopsammon, gnathostomulids, gastrotrichs, marine catenulids (Sterrer, Riedl, unpublished) and tardigrades belong almost entirely to this ecological feeding type. Diatom feeders Diatom feeders, a small percentage, are nearly randomly distributed within these key groups.* Some species of Acoela (turbellarians), harpacticids and other taxa show diatoms quite regularly in the gut; others are too,small to 229 swallow whole diatoms. However, the number Of specialized diatom feeders may have been over-estimted) because often diatoms may be ingested by chance. Predators Predators axe represented but strongly restricted to the very small interstitial types. The interstitial ceolenterates in particular belong to this group. The sarn is true with regard to two turbellaxian groups (otoplanids and kalyptorhynchia 'ns). The former, however, are normally scarce, the latter are generally restricted to surface layers, and both are correlated with coarser sands. The most abundant predator group is probably the nematodes. According to their pharyngeal organization (Wieser 1953) many endopsa n nematodes seem to belong to this group. Decomposers Decomposers within the interstitial system are of great importance. Humm (in Pearse, Hum and Wharton 1942) has shown an average of 200,000 bacteria per gram of sand in the interstitial zone at Beaufort, N.C. The highest count was 1,250,000)" the lowest 5,000/g. An increase from low tide through mid-tide to high-tide level was found; the average values ranged from 34,000 over 110,000 to 486,000 per gram of sediment., In general, the number of bacteria increases as the particle size decreases (ZoBell 1938) or when the percentage of organic matter rises. The distribution and activity of bacteria also varies within the different sediment strata. This is demonstrated by the formation of ferrous sulfide (Bruce 104inthe deeper black layer. The important contribution of bacteria to the beach system merits much closer examination. Patterns and Causes of Species Distribution Among the impo-tant parameters limiting the distribution of organisms in high energy beach systems under natural conditions are desiccation,,salinity, fine sediments and coarse sediments. Desiccation, of course, is one of the' chief dangers for marine life in the sand environment, but rising seas, high capillarity and spray water help alleviate it. Furthermore, the smallest inhabitants of the interstitial space (for example, Tardigrada) are often only 0-3 mn long and less than 0-05 mm high. This dwarf size enables several species to live within the fine water film surrounding sand grains that are only moist. Freshwater boundaries and rigorous salinity changes caused by tide move- ment are also limiting. At the ground water level conditions are much more buffered and a wide brackish zone with a special fauna, mostly marine migrants, connects the marine and the subterranean freshwater biotope. Fine sediment limits the occurrence of the interstitial fauna in two different ways. First, a reduction in the main grain-size-fraction down to 200 or 150/jexcludes progressively all types of the mesops n. Second, the addition of fine sediment to a sand body soon chokes the interstitial system. 230 In cases of tight packing and in less sorted sands (having a broader variety of grain sizes) the amount Of fine sediments required to close the interstitial space can be very small. Too coarse sediment gives ris 'e to a marine desert. There is a size category (cobble) between coarse sand and boulders that is too large to pro- vide the conditions of the interstitial environment, but too small to offer a stable substratum for sedentary groups. Such "sediments" often lie as a limited layer on flat rocky planes at or underneath low tide level. During stronger surf action the whole layer moves, forming a deadly mill and grinding all living structure between them. On days with quiet seas, smoothly polished rock banks with traces of scrubbing mark the boundaries of this layer, which adjoins the higher exposed areas at the surf level on younger rocky shores. Fine sediment regions, on the other hand, are more common in sheltered areas and are always found at greater depths. All biological patterns are in a permanent process of transformation. In order to gain a position from which to describe the processes involved in the patterning of species distribution in beach systems, we are forced to assu and to describe first a relatively stable situation. Furthermore, the causes of species arrangement, the degrees of correlations between them, the amount of information available; and the degree of our understanding varies strongly from case to case. Primary and secondary causes of species distribution will be discussed separately; correlation and an attempt at understanding will follow. Primary patterns Primary patterns are those caused by environmental factors directly and not indirectly, as by species interactions. Such primary factors are mainly the.inorganic gradients, but include also the energy gradients, in- cluding food import. Today almost all our information regarding causes of biological patterns within the high energy beach system is related to environ- mental factors. This is due to a certain extent to the great hydrodynamic stress from the ocean, leading to an unusual predominance of influence of the physical parameters and to high specialization of the edaphic conditions. In other systems, such as coral reefs, mangrove swamps, sea eaves, and algae beds, secondary patterns are known to regulate many subsystems, but even in these systems, primary patterns were the first to be understood. Therefore, the situation with regard to sand systems may be due to the preliminary stage of our knowledge. Species patterns may be an zed by the descriptive approach of studying zonation f irst in its broadest sense; analysis then leads to component corre- lations and synthesis to an understanding of the subunits or associations within the system. Zonations may be considered as the result of a combination of grad- ients. They are three dimensional and vary in their scales from micro- to geo- graphic distributions. Beach profiles have been divided into from three to five zones, according to the species (Davenport 1903, Schultz 1937, Dahl 1953) and the local geomor- 231 phology. The backshore area, or subterrestrial fringe, can be characterized by talitrid anphipodsj by the ghost crab and by the lack of marine mesofauna in the drying surface sand. The frontshore region can be divided into three biological zones according to local conditions: the moist area or the slope contains corophiids on the surface and tardigrades and nystacocarids below the surface. The low water terrace contains typically burrowing arenicolids, thalassinids, cirolanids (isopods) and gnathostomulids in the black zone' underneath. In the surf zone Emerita and Donax of the endofauna, and otoplanids of the mesofauna are most characteristic. In the offshore zone diversity again increases, including very distinct microzonations of nematodes, harpacticoids, turbellax-'.sl and even shrimps (Ax 1951, Gerlach 1948, Noodt 1957 and others; Fig* 38) However, our knowledge cannot be generalized yet on a worldwide scale. Vertical faunal layering is clearly developed, but it varies strongly from zone to zone. In the backshore, for example, there are mainly three layers related to humidity, salinity and temperature changes. Terrestrial dwarf arthropods populate the dry top layer, tardigrades and mystacocarids are mainly in the underlying mist layer and archiannelids, malacarids, iso- pods and amphipods are in the groundwater layer. In the offshore zone, on the other hand, the surface layer holds filter feeders while the deeper strata are layered according to oxygen availability, with only nematodes in the lowest populated part. Coastal sequences, the faunal changes along the coast, are mainly re- lated to exposure, sand grain size and coastal angle as is clearly shown in the meso- and endofauna. Mollusc zonation ranges from Olivia and Donax types in exposed areas to Nassarius and Tagelus in sheltered, muddy, fi7ne sand flats (Fig. 2). Many examples can be given within mesofaunal groups. Much less is known of species zonation within the larger scale of geo- graphic sequences. However, within the macrofauna (Figs. 39 and 4o, Dahl 1952, 1953) and particularly in cases where more information is available, as in lug- worms (Fig. 41) geographic patterns become very clear. Correlations of factors determining zonation are usually made using field ecological approaches at first, and are later studied under laboratory con- ditions. Climat*c edaphic and xenotrophic factors (i.e. food sources from outside the systeZare involved (Jansson 1968 Humidity deficiencies reduce the fauna to smaller size'classes and to life in thin water films covering the sand grains. Presumably, a change from marine to terrestrial types of interstitial fauna occurs when the air spaces increase between sand grains. Light influences first of all the distribution of autotrophic plants, mainly diatoms, within the surface layers. But archiannelids also because of their light sensitivity axe kept within a well-defined layer (Gray 1966). Temperature affects many species in the foreshore and particularly in the backshore regions leading to avoidance of areas of higher temperature or high temperature change, or to migration into deeper areas during hours of most intense radiation. Temperature stability within the groundwater, on the other 232 Haplogonaric syliensis Tur bellaria Acoelo) 1600 - ----- - ---- Oligochaeta -- - Parotoplanince ( Turbellaria Otoplanidoe 1400. Trilobodrilus oxi ( Archiannelida 1200- Microstomum spec. ( Turbelloric Macrostomida .......... . . Prolodrilus choefifer u. P symbioticus (Archiannefida 1000. goo Soo 700- 600. 5W E 400. 300- 200- 100 so :2 80. 70- 6o- so. 40 30 20- P 10. 0 HWL (co. 1.50) Pralthang Quellhorizont watt 2.7. 25 23 21 19 17 15 13 11 9 7 5 3 1 Proben a ' I ' " ' I ' I ' I - j 1 4. + + I. f. . .... r --- Fir- 5 1 3 2 1 0 1 2 3 1 5 6 7; 8 9 10 L [m) Fig. 38: Ydcrozonation within the well horizon (quell horizon ) of the North Sea in July 1964 showing distribution of 6 species of the mesopsa n (From Doerjes 1968; Fig. 10). 233 El ............. 7@ --------------- e- ........ .................... ----------- Fig. 39: Distribution of talitrid amphipods which dig in sandy beaches, and of the crab genus Ocypod . Black circles indicate location: and number of araphipod species (1-4) with this ecology Dis- tribution of,OcZ2ode-is shown by the stippled area between black lines (From Dahl 1952; Fig. 6). Arctic North Temperate -.Tropics Soitch Temperate Antarctic Subterrestrial rringe Midlittoral Zonc 3qMV 3 3 47' 7 rringe 6 Sablittoral 44 ffi'@L 5 5 Fig..40: Generalized diagram show@ zonation of sandy beach crustaceans in'the main climtic zones of the earth. 1. Talitrid amphipo4d;,2. ocypolid, crabs; 3. cirolanid isopods; 4. lysianassid amphipoas (genus Pseuda- librotus); 5. oedocerotid amphipods; 6. hbustoriid e&phipiods; 7.' hippid crabs; 8. phoxocephalid amphipods (From Dahl 1952; Fig. 8). 7" 234 0 10 0 20 'Key to the forms genus Arenicola 0 marina marina (L.) the " cristala group marina schantarica, Zachs 1929 marina glacWis Murdoch 1885 0 cristala Stimpson 1856 (D brasiliensis Nonato 1958 lopeni lo.veni Kinberg 1866 glasselli Berkclc'y & Berkeley 1939 lotmi sudawiraliewe Stach 1944 E) bombaymi, Kewalramani et al. 1959 Fig. 41A: World distribution of the lug worm genus Arenicola (From Wells 1963; Fig- 5)- 235 0 btt; IL 20 70 10 genus Abarenicola (forins with statocysts) arrhnifi.f brerior Wells 1963 Iffinis affinis (Asbworth 1903) V alfitris africana Welk'1963 assinlihs assimilis 01"Idel's 1897) rhiliensis Wells 1963 V assimilis insularuni Wells 196'3 (Z T arSimilis depia Wells 19G3, V gitc,hrish Wells 1963 assinjilis haswelli Wel Is 1961. gi-ims Abarenirola (cystless; forins) pusilla (QtsatrcfajkV-s 1865) claParedii claParedii (Levinson 1983) claliaredii vagabunda I lealy &, we'lls l9r)q A, fiacifica Healy& Wells 1959 claparedii "@anica Healy& Wells 1959 Fig. 41B: World distribution of the lugworm genus Aba,renicola (forms with statocysts) (From 1963: Fig-' 5) - 236 hand, is one of the min factors permitting the existance of its typical fauna. Salinity gradients affect faunal distribution in three dimensions. First, there is a remarkable faunal change from the purely marine' through the brackish, to the limnic groundwater zones. The same is true for salinity changes in the surface sands, from open marine shores to freshwaters in estuaries (Fig. 42). The third faunal change occurs between groundwater and surface sands in the upper foreshore region. With changes in respiratory gas levels, dramatic changes in the fauna are to be observed. With increasing depth into the sediment, oxygen vanishes and turbellarians start to disappear (as shown by Jansson 1967). Number's of nematodes also decrease. At the sane time, saprophytic bluegreeh algae, gnathos- tomlids and a new suborder of catenulid turbellarians increase (Rie!@I, unpub- lished). Earlier it was assumed (Wilson 1952, Pennak 1951, Delamare 1953) that purely calcarous sands wouid bear no interstitial fauna, or at least a very restricted one. This, of course, has been disproved (Renaud 1955)@ The fauna of this almost always tropical organogenic sand may be as rich as that within quartz sands. However, our information is still in a preliminary stage. Sand grain size is clearly a dominant factor in the distribution of many groups studied. It determines the lower limits of porous space available for interstitial fauna. Among the endofauna are species such as cumEiceans (Wieser 1956) which show a very distinct preference for grain sizes less than 1601-A . which they are able to turn easily in order to lick the epigrdwth. Distribution of mesofaunal species depends on space dimensions, as shown with hydroids, turbellarians, gnathostomulids, gastrotrichs, archiannelids and others (Boaden 1962, Gray 1967, Riedl 1969, Schrom. i966, Sweamark 1957, Sterrer 1965, Wieser 1959). The lower grain size limit has been drawn at around 200,1A (Fig; 43) for most groups, but gnathostomulids can exist in sand with grain size at 150,m and less (Wieser 1959, Jansson 1967, Riedl 1969). Food input, mainly from the sea, also affects faunal distribution. Pop- ulation density increases near surface strata and in proximity to wave activity. However, the relation between pelagic food sources, hydrodynamic forces, and grain size and the filtering function of the sand is still unknown. Subunits of faunal grouping within the high energy beaches can be proved statistically and described as associations of species which are regularly to be observed. The causes of such associations and their function will be dis- cussed, but our knowledge is limited and no overall picture can be drawn on a worldwide scale. Six examples will be given. 1. A low-water-step or well-horizon fauna (Fig. 38) has been defined (Reinane 1933a). It is characterized,by the dominance of otoplanids (turbell- arians) and seems to have a worldwide distribution. The subsystem is characterized by high energy input, groundwater outflow, coarse and strongly moving sediments and exceedingly quick and haptic species, mainly predators. It may have a cer- tain autonomy in that beached plankton and stranded meiofauna are the main food 237 so. 30 20 Arlri MJI'117e .4rIen S.'S.Zser r1er ar!et '*-'xase /7' -j- 'VW .20 @+VCM 8,04was 17 PS P19 I's Sol.?;ehall Fig. 42: Nematode zonation within the shore slope. Species number in relation to salinity (A) and to sea level (B). Yarine species are represented at the left in each figure, fresh- water or terrestrial species at the right, and brackish water species are between (lined area) (From Gerlach 1953; Figs. 10, 11). >40o 1400 7 0 q <100 5 (34 4 3-4-3 2 ON - 0 0@ (5.0 f Z> -2 b 06 A-P Y.i. (151-3(3 -46 7-9 > 10 (100 Fig. 43: Distribution of endo- and mesofeLuna in relation to grain size in five locations along Paget Sound. "Fouisseurs" refers to digging organisms (endofauna) and "interstitiels" to interstitials (mesofauna) (After Wi eser 1959, from .4rIen w".r Dela e 1960; Fig. 27). 238 sources. 2. A passive migratory layer covering the whole foreshore area has similarities to the low water step fauna (Rieger and Ott 1969). A selected group of very long and slender acoels, kalyptorhynchs and coelogynoporids (turbellarians), and nematodes migrate with the shell material up and down with the tide. Using the surface material as a lift, they benefit by remaining con- stantly within the zone of maximal energy input. 3. The humid zone, an area "between interstitial tide-marks" including the space of capillary forces above it, is characterized by infiltration of air within the interstitial system. Capillary forces bring fresh and brackish water to the surface, evaporation takes place and salinity increases. Rain- fall and heavy surf influence this balanced situation. The fauna has strong brackish water elements (Gerlach 1963) but also terrestrial components. A certain autonomy from the other interstitial environments is based on its food sources. Wrack material (higher algae and seaweed) often becomes imbedded in and important within the humid zone, forming layers of detritus in,various stages of decomposition. 4. The brackish ground water bed underneath the backshore area is char- acterized by various archiannelids, copepods, isopods and amphipods in all stages of adaptation to subterranean freshwater. Very small (0.5 to 2.0 mm) and slender types are selected (Fig. 44). The independence of this subsystem is based mainly on its food source, detritus brought in by the current of con- tinental groundwater. 5. The black zone in the deeper fore- and offshore area, bounded by a strong redox-discontinuity layer (Bruce 1928b.,Pennak 1951, Perkins 1957, Fenchel 1969), can also be defined by its lack of oxygen, by its special fauna of (mainly) gnathostomulids and catenulids (Riedl 1969), and by its unusual food sources, including anaerobic bacteria and saprophytic bluegreen. algae (Riedl, unpublished). 6. Finally, a whole series of zones between the exposed and sheltered extremes of the sand beach have been defined, mainly in terms of dominant species of the sand surface (Remane 1940, Ax 1951, Gerlach 1953, Noodt 1957, Bilio 1963), very characteristic for the Baltic Sea (Fig. 45)- Secondary patterns Secondary patterns of species distribution are found within the endo- and mesofauna. Species arrangement in these cases depends on groupings based on primary distribution patterns. Since clarification of most interspecies relationships is still lacking, much less information is available on secondary patterning. Within the endofauna, a surprisingly great amount of commensalism has been discovered. Some groups (e.g. erycinacean bivalves) show a high percentage of commensal types, and "most of the hosts are slow moving, almost sessile forms., which burrow in sandy or muddy bottoms" (Boss 1965)- In a more primitive stage the co nsal is not very selective; sedentary animals such as entoprocts and 239 XgjS t c n 9 r u n d w a S s e r - Rarldhoh I e P - V e r t r e t e r T@ Barb. Trogloc Ti _91om, MVDarl Muhid. Microc. Stygiom. S gid. 0.5 Angel.0 io 20 Typ c Fig. 44: Relationship of body size of organisms to the chosen immigration route'frox the sea to sub- terranean freshwater'. Left, interstitial mig- rants; Right, sea cave migrants (From Riedl 1966, Fig. 142). IJn C+ 0 C, ct C8 C+ @ s I Cf- (D rx P@ Cl. s I I ca: Ck 0m FA. P, 03% C+ 03 P) 0 0 (D P, C+ F6 0 H (D p 0 W-1H P @? %.A W U. R 9 a -317 CXQ (TQM (D rL 0 '0 0 cr zr cf- FJ (DM $3,4 04 (D (D (D ci- FA. m 0 F-J m (D ci- 0 '.3 (D P. 0P, Z5 m ottz 0 241 hydroid species use the shells of living clams (Donax) and crabs (Emerita) as a relatively stable substratum. The strong hydrodynamic action offers excellent conditions for them, and the migrating macrofauna, which travel with the tides and settle in the surface layer, offer adequately stable sur- faces for attachment However,the macro-species are even more attractive to commensals if they provide true stability. This is particularly the case for types settled in relatively permanent tubes such as arenicolids (lugworms) and thalassinids. Up to nine different commensals are known to populate a single species (Fig. 46). Although this seems to be a high amount of commensalism, more recent papers have made it clear that discovery of new commensal relationships will continue (Sander's et al., 1962, Jenner and McCrary 1967). Obviously living stability i. e. stability provided by macrofauna which adapt and compensate) creates oases of high attractiveness within an environment of great food supply but of unfavorable changeability. For the meiofauna of the endopsammon, information is too limited to permit drawing a more general picture. We do not know whether this lack is based more on greater difficulties in observing species correlation in the psammon or more on a true reduction in inter-species relationships, due per- haps to edaphic limitations or difficulties. Within the microscopic mesofauna true commensalism is also detected. It mainly involves syncarids and interstitial isopods and amphipods bearing commensal suctorians (Delamare 1960; Fig. 47).. The majority of interspecific relations, however, such as that of predator and prey are not yet clear. This is because they have no permanent and solid contact, and because direct obser- vation is not possible. All information must come first from statistically significant correlations; causes and effects will have to be analysed after- ward. It can be predicted for example, that the distribution of diatom feeders will be correlated with algae zonation and so on; however, we do not know how selective most of the grazers and predators are. A few examples may illustrate the complexity to be expected. Colonization experiments with sterilized, sand within the natural environment have demonstrated that diatoms, diatom-feeders, and predators follow each other in sequence (Boaden 1962, Renaud-Debyser 1963). The zonation of some gnathostomulids within the black layer is almost identical with that of one of the bluegreen algae in this area; a direct connection therefore is probable (Riedl, unpublished). Finally, choice experiments, have shown that Turbanella (gastrotrich) avoids a sediment which is or has been populated by Protodriloides (archiannelid). The degree of interspecific correlation is important mainly in eluci- dating the structure of a biotope, but in the sand environment it is less clear than in other near shore biotas. This may be due to the tender age of psammo- logy as well as the peculiarities of this three dimensional,, opaque, and shifting substratum. Actually, modern psammology is still in the descriptive stage, since not even all the main types of its biota are yet described, and large geographic, areas remain completely unexamined. In some areas, as in the north European 242 e ron Pinnixo odventor longlpes Clevelandio Ahn4o /bS fronciscano URECHIS crypf-yo Sclaroplox Callformca 9-010to UPOGEBIA f 0 Pseudopythm to SPPL CALL! NASSA Giffichthys Betoevs ml@abjI4 longdactylis esperonoe Hemicyc S omplonoto SPP Annao Schmitti Fig. 46: Cormensals of the echiuroid, Urqq @ @his and the burrowing crustaceans, U. b'a and Callianassa poge_a_ (From Dales 1966; Fig. 4) 243 a 2 Ou C, Fig. 47: Commensal suctorians (Tokophyra microcerberi Delamare and CbAppuis) on the amphipod Microcerberus remyi Chappuis (After Delam e and Chappuis, from Delamare ig6o; Fig. 254). 244 coast, the fauna is becoming fairly well known and the distribution patterns of some key groups have been studied. Species relations are only beginning to be clarified under laboratory conditions. It may, therefore, be too early to predict the degree of species correlation which will eventually 'be shown to y @ . characterize the sandy beach. However, @he high energy beach is a geomorphologi- cal entity and presumably a biologlcal entity as well, with a multitude of interlocking aha homeostatically f!@ction-ifig components, protected, or at*least delimited, from neighboring systems. One group of such interconnecting com- ponents is based on interspecifie'relatibns. Others are based on common food sources, general edaphic structures and/Qr common gradients of key climatic @ iogidal feaiures. At he factors all integrated by geomorpho least one of t. causes underlying species correlation must'be.stroag,'if even moderate homogeneity is to occur. Since most of the physical patterns which give rise to high energy beaches are strict and rigorous, an4 probably dominate the system, interspecific relations may play a relatively small role@in keeping the system in order and functioning. Dynamics of the High Energy Beach System Just as the existence of each orgapism is based on a permanent flow, interchange and exchange of energy, substances, and structures, so does the existence of each ecosystem depend on'their balanced flow. This an logy should not be exaggerated, but clearly a@i ecological unit must obey the laws of its living components, as well as the laws goyerning its entity as a balanced system. Permanent trophic dynamics Not only should the lines and loops of the food chains be followed through the individual producer, consumer, and decomposer steps, but the whole balan6e between input and output should be examined. Primary producers, autotrophic plants, are restricted to microscopic, interstitial grou s, mainly diatoms. In pheltered areas, this benthic plant 'p .life may be dense, but it is restricted to the top centimter (Pomeroy 1959) and tends to migrate to the surface (Aleem 1950)- In high energy beaches, how- ever, the thatIom'population is scarce (20g C/m2) and the yearly production is very low (4-99 C/m2). These organisms may extend down to 20 cm, however, (Steele and B@ird 1968), and this raises two min questions. First, since mixing of sand over long periods affects no more than the top 5 to 10 cm, populations below this level have no access to light for several months. One might assume that these diatoms assimilate carbon heterotrophically (Lewin and Lewin 1960), but to other authors (Hinro and Brock 1969) this seems unlikely. Second, it is obvious that the small productivity within the system does not cover the system's general needs. Thus, other stronger food, sources brin,&ing: energy from outside can be predicted. Among the consumers, there are only a few groups of macrofauna which con- tribute energy to the system by collecting food from outside. One type of endofauna collects food outside and releases feces within the substratum (Emerita Amphioxus); a second type collects outside but also releases wastes 245 outside (Card Donax); a third type filters particles from the s and and deposits feces on the surface enicola, Balanoglossus). The contribution of these macro-organisms may be considerable, but little data are available. The contribution of the filtering mesofauna seems not to count quantitatively, nor is it clear how much they really take from outside the system. The largest percentage of the pse n species feed within the sediment layers themselves. Remane (1952; see Fig. 48) shows the high diversity of feeding types. However, the participation of several other groups such as heterotrophic or.saprophytic plants has not yet been evaluated. There is evidence that bluegreen algae reach a density of 10,000 cells per liter of sediment in the deeper layers, equal to the maxima of nematodes (Riedl, un- published), but their contribution to or position in the food chain is unknown. Undoubtedly, the decomposers have a key position in the beach system, due to their density and their variety of functions. Humm. (in Pearse et al. 1942) counted 200,000 bacteria per gram of sediment belonging mainly to the Ti-tTogen- cycle, agar- and chitin-digestion groups. Besides these, the sulfur bacteria (Fig. 49) are of great importance, particularly in the black layer. Altogether 16 different functions of bacteria within the sediment are listed (ZoBell 1938). Decomposers in the sand environment obviously represents also an important food source for a great number of consu rs. Whole phyla might be specialized on them. The energy input and output relationships of,the-beach system - all the correlations with neighboring environments - are still unsolved. A great energy input is to be expected from the open sea, but wrack beds, birds, and groundwater flow also contribute energy to the system. Adequate data axe lacking. It has been generally assumed that detritus and plankton washed up on the beach my be one of the main food sources of the psammon. 'Yet cadavers of planktonic organisms are seldom found within the porous system and only the smallest types of phytoplankton can fit into the interstices. In contrast to this, the content of organic matter my be remarkably high. The senior author therefore suggests a theory of a "beach-filter-mechanism." , as follows. First, dissolved organic matter in sea water ranges mostly between 0-5 and 2-5 g carbon per ton and the values are especially high in surface and coastal waters. Second, bubbling air through a seawater column creates foam at the surface, the amount of which corresponds to particulate matter 1moduced., which may be a food source for invertebrates (experiments with sea-aquarium techniques and experimental oceanography, Sutcliffe, Baylor and Menzel 1963, Barber 1966, and others; for criticism see Menzel 1966). Third,, the surf may be considered as a permanent and effective bubble mechanism, extremely fine bubbles reaching a depth of thirty meters (Riedi 1966). Fourth, within the whole critical depth, the oscillation of water particles underneath the waves reaches the bottom. Thus, not only does the foreshore region receive strong input from each wave, but a large part of the offshore region mast also be included. In the foreshore region gravity contributes to the penetration of s-urfwater into the sand-body. In the offshore region mixing of water with the sediment surface layer is important. Also the suction effect of the boundary 246 or the Epi- psommon (Crangon,efc.) Internal filterers of the Endopsorn mom ( Mussels, Gronchlostoma) Predators of the Endopsommon and - - - - - - - - - - - - Mesopsommon External filterers of the Mesopsommon '\6S Fabricolo Scolecol- des pjs,Mano6r.yoz*on PIC te Detritus (and bacteria) z Sand-toters of the Endopsommon 1' 9 of the (Arenicololophelio, Endoosommon Paronois. (Cumactons, outochthonous Scoloplos, etc.) Amphipods, etc.) diotoms'etc. Sand hunters 'of the kers and Mesopsomman Epi- iuckers (rIpt-slucic h S. / Nematodes. (Aydrobio, Archionellids. O'@(Tod,.,S.d,s,'@@ichocerco ) Copepods.Ostracods. Endapsommon Turbellarions,etc.) Echloocordlum Fig. 48:, Diagram of feeding relationShiPs of the sand fauna (After Remane, from Hedgpeth 1957b; Fig. 7). R.@O- FRS] RSO, (,rKj09ACTERtA)----- Fe 2 0,1 H7.S njH 0 F r S FeS Fe2S, REDUCING OR ANAEROBIC OXIDATIVE Fig. 49: Sulfur cycle in a marine beach (After.Bruce, from Hedgpeth 1957b; Fig- 5). F 117SO, 247 layer, migrating with the permanent translocation of the pattern of particle speed near the bottom may cause a flow through the interstices from locations of minima to maxima of oscillation velocity. Within the sandripple structure this suction pattern may even become stable. Fifth, finer fractions of the sediment attract very small particles and possibly even the most extremely fine particulate matter. Theoretically, these five components together form the world's largest physical filter of organic matter. Only theories axe available with regard to input problems, but even more obscure are the phenomena relating to output of the biological beach system. Very few live adults or larvae of the psammon may be expected to leave the sand environment, so C02 and nutrients my be the main contribution of the sandy shore to the overall marine biosphere. Rhythmical changes As in most coastal environments, rhythms are strong. They control population fluctuations, faunal distribution, and physiology as well as var- iations in behavior. Three main types of rhythms can be distinguished according to their length and the causal forces involved. They influence each other. Tidal rhythms change the energy pattern, humidity, interstitial oxygen (Fig-50) groundwater flow and other parameters. The epipsammon follow exactly the translocation of the shoreline with the tides. Many groups of the endopsammon do also. Emerita. (MacGinitie 1938 1, Pearse et al. 1942) and Donax (Fig-52, @bri 1938,Marsh-1-9-677 are good examples. WithiTth-e mesofauna, the earliest case reported was Convoluta. roscoffensis (turbellarians; Gamble and Ked-le 1903) which appears in masses during low tide, forming green'patches on the sediment surface and exposing their symbiotic algae to the sunlight. Most behavioral adaptations to the tidal rhythms may be still undiscovered. However, it was shown recently (Rieger and Ott 1968) that five types of migratory patterns can be observed: active vertical migration with the tide, active vertical migration against the tide, active horizontal migration at low tide, passive-migration with the tide (riding on drifted shell), and mixed types of migration. Circadian (daily) rhythms change visibility and surface conditions within the back and foreshore areas. Shorebirds are active in the daytime, while ghost crabs and egg-laying seaturtles appear at night. Convolut appears at low tide only during daylight hours and some behavioral patterns of vertical migrators (mentioned above) are under a circadian regime, due to loss of humidity and raising of temperatures during strong radiation. Seasonal changes are due mainly to the influence of water and air tem- perature directlyand indirectly through their effect on other parameters such as oxygen (See Figs. 7,8,9,51 and Table 1,2,3,6,7). Growth, activity, breeding and many other processes are seasonally directed and nearly all species within the system are affected. Furthermore migration and density of populations are related to seasons. Populations of one of the typical intertidal amphipod species decrease in winter and move seaward (Dexter 1967); the same is true for an intertidal turbellarian (D6rjes 1968; Fig. 53). The opposite holds for some moist zone tardigrades which approach the shore, with a minimum population in Y summer (DeZio and Grimaldi 1966). 248 RISING TIDE B. (ial) 3 6 0 3 6 0 0 (cat) AIR I" 6- 0 FALLING TIDE ____0 0 .OP. 8- 10- 20 - Hows ABOVE WATER WATER LINE BELOW WATER LINE LINE Fig. 50: Change in oxygen concentration in interstitial water. A. according to length of time that site (Whitstable, England) was exposed by the tide. Triangles represent surface water; circles, interstitial water at 2 cm. depth; squares, inter- stitial water at 5 cm depth (After Brafield 1964; Fig. 5). B. during rising and falling tides (Corona del Mar, California) (From Gordon 196o; Fig. 1). 0- 2 100 4- 0 J 30- 50 - U W20- 0 .9 z 10-1 W 0 0 0 A M j J A 5 0 N'Dj J' F'M'A'M'JL J' A'S'O N D! 0 50 MONTHS FINE SAND Fig- 51: Relationship of anaerobic black layer to depth and fine sand. A. variation of black layer with depth and temperature at Whitstable, England over a period of 22 months. B. relation- ship between oxygen concentration of the interstitial water and percentage of fine sand in the substrate samples, Isles of Scilly. Solid circles indicate black layer (Gordon 1960). -------- rn Fj @pw tpl \.n comF, 00 cf- ci- C+ (DM0 \0 (+ C+ FA coo ).o 00 bb 0Pi 100 tj :E (D C-F =D CD P,0 .@Q HZD' 0P. ci CF+' O-V C+ F' Id C+ Eq 011, C* P& m ci- (D c-F (D P,0F4 oq0P, 18p11 ci- \-n (ndividuen In 2,5 ccm P, i--o 0 pci- ci. gu C+ F, (D tj C+ 1@ ci. ID J.@ C-i. (D Fl ----------------- (D c+- --------------- 00Fl n ----- -------- 04 ------------ co 'N Ilp 0P ---------- (D XP.w R 0H m 10FA \.n c-F 0t@4 0rs C+ s F'.m a 0ct (ID 6frZ 250 Mixed types which are dependant on more than one of these rhythms might be expected to be rather abundant, but clear examples axe difficult to find. Convoluta has been mentioned. One of the most striking examples is in the macrofauna, an atherinid fish,,the grunion, (Leucresthes; Clark 1925, Korringa 1957). It spawns during a I to 3 hour period in summer leaving the water at night immediately after spring hightide. On such a night the exposed part of the foreshore may be covered with mating and egg-depositing specimens. Develop- ing eggs buried in the sand, are designed-to be protected a fortnight and to be washed back to the sea with the following spring tide. Biological successions in high energy beaches, non rhythmical.and often non reversable, vary greatly in their time scale. They range from intervals of an hour to geological times; from the time it takes to conquer a new micro- niche to the lifetime of the shelf system of a continent. Within short intervals, direct observations are possible, while long time effects can only be derived. In short term succession, it would be interesting to know the time re- quired and the processes involved in the conquest of new substrata, in the balancing of conmunities and in community aging and disappearance. Only a few of these problems have been touched however. Sterilized sand put back on the beach becomes repopulated rapidly and'its biological balance is reached in a short time (Boaden 1962). This is understandable because all the biotic elements axe very near and ready to expand into the new space. Yet very isolated sands are also populated in a relatively short time: A seacave within the steep rock of Banjole (northern Adriatic; Riedl 1966 P. 59) contained no sand from 1952 to 1-964. Boulders appeared in 1961 in its background and were undergoing grinding in 1962; coarse sand and shell with ripplemarks were produced in 1964. In 1965 and 1966 this sediment had already assembled otoplanids (Riedl unpublished). Yet the nearest environment with otoplanids was two miles away on the shore. Unfor- tunately, nothing is known regarding the processes or the time required for ripening or ageing the sand biome. Long time successional effects are related to permanent change in the beach profile and the whole coastline. Large amounts of surface sand are trans- ported daily and the profile of the beach changes with wave action. Often retreat of sand produces large cuts (Bascom 1951; Fig- 54A) and sand accretion occurs in smaller steps. Biologically this means that in an eroded area either most of the sand fauna are lost or they have mechanisms to protect themselves such as by hiding in deeper layers. It also means that vertical zonation and layering must change daily. As a matter of fact, nearly all species tend to migrate, even the smallest types within the interstitial spaces. The tardigrades migrate up to a foot a day (DeZio and Grimaldi 1966; Fig. 55). Everything is in motion in the sand.and a specimen my never reencounter its place of birth. In places with high sediment output and strong waves and currents, as in inlets of estuaries (Fig- 54B), coastal lines change dramatically. In cases such as Aveiro, Portugal, where data over long historical periods are avail- able (since 1318, according to Abecasis 1955) changes of beachlines are especially striking.' And on the geologic time scale, we need go only into early Pleistocene to see changes in continental dimensions. It is evident that the psammn have easily followed all the physical translocations of sandy beaches, the most movable part of.this ancient system. +2 49 @46 Fig. 54a Qj Fig. 54b CARMEL, CALIF. STATION I-S A I Z Ar r I C ,Sr 0 A GROWTH J 0 RETREAT % 61 1860 oLMLL* 00 200 WO 500 VISrANCE - FEer 1879 Fig. 54: Deposition and erosion of exposed beaches. A. at Carmel California over a period of several months (After Bascom); B. at East Rockaway Inlet, N.Y. (After U.S. Army) (From Wiegel 1964; Figs. 14.24, 14-35)- ... 09. 20-VI.63 V I.Y.63 10.IV.63 V.111.63 26-IM 20.:.63 q.x 1.62 1926 19-XIA2 77, . RX.62 19.D1,62 m 10 17 16 15 14 13 12 11 10 9 9 7 6 5 4 4 5 -9 7-9 S-TO -11 192T Fig. 55: Shoreline displacements (unbroken line).and highest fre- CE A AF owl' qupncies of Tardigrada.(broken line) relative to the I A rL A JV r I C 0 average shoreline for a one year period (From de Zio a&. Grimaldi 1966; Fig. 4). 252, Chapter A-3 HIGH VELOCITY ECOSYSTENS In channels where sea waters flow at high velocities, 3 to 20 miles per hour or more, bottoms are swept clean of fine sediments and reef-like accumulations,and specialized encrusting organisms develop growths, taking advantage of the foods avail@ble in the rapidly passing waters. The same kinds of ecosystems also develop on the bottoms of ships where they axe some- times called "fouling communities" and inside large pipes through which sea waters are pumped as in industries where waters are used for cooling. In nature the system occurs on hard coarse bottoms where tidal flow passes through narrow passages and inlets. The very strong current dominates the system and allows dense patterns of attached organisms but also is a source of stress requiring energies to be expended by th6 organisms in adaptation. If the surface is within range of light, heavy algal growths develop facilitated by the rapid renewal of nutrients for photosynthesis. High velocity channels are favorite collection locations for dredging of marine organisms in quantity. Because the high currents often occur in high salinities at the entrance to estuaries where conditions, other than current, are uniform, species diversities tend to be moderately high, but ,diminishing with current. This system is found in every state of the U.S. but one of the best studied examples comes from abroad. EXAMFM Lough Ine Rapids. A much studied ecosystem is the Lough Ine Rapids in Scotland where a strong tide flows in and out of a Scottish loch forming a shallow salt water rapids in which grows an enormous concentration of plants and animals as illus- trated in Figs. 1-4, taken from a recent review article of these studie's (Kitching and Ebling, 1967). Heavy growth of algae supports a food chain of algae-eating sea urchins (Paracentrotus). Laminarian brown algae grow in other zones, supporting encrusting bryozo-a-71th densities that vary with the current (Fig. 4). Invading with different stages of the tide and time of day are crabs and fishes that eat animals from the rich bottoms when slack currents permit (Figr..2 and 3). Worm Tube Reef in a Cooling Intake Pipe Heavy calcareous reefs built by animals in the pipes of fast flowing salt waters occur in the intake of the Corpus Christi Power and Light Company, Texas (Behrens, 1968). The growth rapidly closes the pipe unless prevented (partly) with chlorination. The waters drawn into the pipe come from a polluted harbor, which may account for the simplicity of the worm tube reef,exclusively of Hyd.roides norvegica, Gunnerus. This'serpulid is also found on the bottoms of ships that enter -the harbor (Fig- 5). The larvae are released into bay waters (Fig. 6). Other cooling pipes have simple reefs of other species. Hutchins found mussels forming reefs (10 lbs per square foot -in 4 months) in cooling pipes in Massachusetts (Woods Ho.Le Oceanographic Institution, 1952a,). The'prqp@em of reefs in pipe may be very serious. If chlorination is used to kill intake organisms, the system 253 0 0 0 C57: 0 0 0 0 C, e 0 GOO a 0 0 0 0 G 0 00 0 00 0 ./ G 000 0 0 00-6 00 0 0 000 0 0 e e 0 1 0 * 0/ so, so HimenthoNo efo.9010 I Cod;um fragile -<-N- METRES 00 Socc-hiro Potyschides LamMorio digifuto Laminaria socchar' The distribution of dominant sublittoral algao in the Lough Inc Rapi(k September 1946. The Codium fragile is subsp. tomentosoides. .................... -------------------- - VD 2-6 2-4 _79 N Maximal currentz (metres/sm) ------------ 24 24 3 52 is 23 7 jI.. 0 so N -vC- Metres Mean total flow (km.) per udd cl," L Water currents at level of the canopy. (a) Maximal currents in metres per or (b) Mean total flow in kilometres per tidal cycle (based on average of figureS f and nesp, tides.) Fig. 1. A salt water tidal rapids in Scotland (Kitching and Ebling, 1967). 4 "771 @4 41___@2 0 So Me a. @wtl fl'.. 254 Tide in the lough 20. EAST GOLEEN Carcinus m.mnas 0. Portunus puber 0. A A A A 50 Prawns & shrimps Z 20 GLANNAFEEN QUAY Cardnus menas 0 5 Portunus puber 0 so Prawns & shrimps A k 0 lil i4 6 12 18 24 6 12 is Time (B.S.T3 Numbers of crabs and prawns on beds of small mussels laid in extreme shelter at East Goleen, and in a more open part of the Lough at Glannafeen Quay. Black signi - fies sublittoral, white signifies littoral. Carcinus maena8 and Partunew puber were opening and eating the mussels; the prawns (mainly Leander serralus) were merely scavenging. Fig. 2. Swimming carnivores in the Lough Ine Rapids (Kitching and Ebling, 1967). J.@LIILAA rLL 255 Time of activity DAY Birds NIGHT Cancer Portunus arcinus Marthasterias puber DAY Porac ntrotus Gibbuia ciherario NON- A\ttach rd---@ - Anornia MIGRATORY algae Plankton Diagrammatic representation of major food chains in the ParacentroJU8 com. munity in relation to times of daily activity. Fig. 3. Urchin-algae food chain in Lough Ine Rapids (Kitching and Ebling, 1967). 40. Z@- 2 a A 7 30. 0 0 0 0 S"Od d hs.. ff- in M.- P., -.a Population density of Patina pellucida on Saccorhiza polyschides (whole plant) in relation to the speed of current at fastest flow (in metres per second). For position of stations see Fig. 4. September 1946. 0 mean number of Patina per-Saccorhiza plant; 0 number of Patina per 3 lb of Saccorhiza. Fig. 4. Populations and current velocity in the Lough Ine Rapids (Kitching and Ebling, 0 pUber P e All\ ".%0 ARANSAS PASS ONE Day \REDFISH BAY "ofk EXHAUST 10 4P Central ARANSAS BAY Power a HAKDUK Light Co. corpus Chrl sti Bay City of CORPUS CHRISTI S.JOSE 1:s ISLANID .016 41 SCAE 1ARDS GULF 0 MEXICO 0 100 200 ARANSAS PASS Location map showing the cooling water intake tunnels on the North side of the harbor of the city of. Corpus Christi, TeXaL Fig- 5- Site of wormt Ing intake pipe in Texas (Behrens., Fig. T. Map ShOWing-Aransas Pass inlet with jetties reef in e003 1968) 2-57 will serve to deplete bays of larvae, foods, and biotic food chains to whatever extent the bay waters are'pumped. Aransas Pass Inlet- Aransas Pass (Fig. 7) is one of the many narrow inlets through which main currents of estuarine exchange flow in and out of the open sea. Dredging in this inlet produces coarse rubble of encrusting reef animals including sponges, oysters, bryozoa, barnacles, mussels, and other filter feeding animals. The seasonal pattern of larval release from reef-forming animals in the inlet is given by Behrens (1968).in Fig. 6. Other data are in Fig. 8. One of the carnivores of the rocky, margins is the stone crab which can break open encrusting skeletons. Powell and Gunter (1968) (Table 1) found seasonal changes in sizes. Black Abalones from California were introduced in the pass in December'1959- They lived on the rocks until high temperatures of summer. Beaufort Inlet, N.C. With higher tides than at Port Aransas, a wider channel is maintained at Beaufort Inlet, N.C. (Fig. 9A) strong currents being spread over a wider zone. Ingram (1965),as shown in Fig. 9Bmaps coarse sediments of shell and s6nd with little residual organic matter. The fast and turbulent injections of waters from estuarine and open see sides alternate with the tides, most plankton being recently injected from less stirred"'areas and removedJfrom. the inlet before any kind of adaptation may take place. These plankton populations, however, are the basis for rapid growths of attached animals on sides and bottoms. William and Murdoch (l964 (Fig. 9A ) measured weight of plankton, chlorophyll reprpsenting phytoplankton, and bottle measurements of photosynthesis and respiration serving as an indication of the physiological state of the cells. The seasonal pattern of larval release and setting mainly runs with the pulse of available plankton production,,March to November, as given in Fig. 10 (Woods Hole Oceanographic Institution, 1952a)- Rollover Pass, Texas A much studied inlet in Texas is Rollover Pass shown in Fig. 11. Probably because nearby Galveston inlet (Bolivar) was deepened for navigation, sediment filled in the small natural pass. At the behest of sportsmen it was dredged open in 1955 (300-1800 ft wide), although it soon filled up again. While open it was a popular fishing location and Reid (1957) studied the fishes before and after the changes, describing the inlet as faunistically rich with speckled trout, croaker, spadefish, drum, redfish, pigfish, silver perch, pinfish, ladyfish, catfish, rays, sharks, bluecrabs, eels, and pompano. The Floating Buoy Buoys are anchored in channels and inlets and have very fast current regimes with rapid growth of the attached ecological system. In Table 2 and Fig. 13 are shown the weights which accumulate, these in addition to the export of growth to the many animals that feed on these reef-like accumul ions. Iu Fig. 12 is shown a much quoted diagram of the early start of succession with the bacteria making an immediate slime covering followed by algae (if 258 barnacles @.A ......... oyster's 11.900- .1,000 ............. %% % % 100 % 100- serpullds -10 J F N A N J J A S 0 N 0 J Numbers of larvae of the three most abundant fouling organisms settling and meta- morphosing on filter screens in flowing sea water system at the University of Texas Marine Science Pier Laboratory on Aransas Pass inlet, Port Aransas, -Texas. Fig. 6. Larval set in Aransas Pass Inlet, Texas (Behrens, 1968) Table 1. Measurements in millimeters of stone crabs taken from the south jetty (Mustang Island) of Aransas Pass. (1947-48) December January June July August Number 10 45 71 73 95 Range, Width of Carapace 9.8 to 5.5 to 4.2 to 3.9 to 4.8 to 17.1 49.0 74.6 80.0 62.4 Mean Width of Carapace 12.32 22.53 24.97 29.95 24.74 (Powell and Gunter, 1968) 259 Harbor 130Y Aransas --------- April 23 20. April 30 Gulf of Me KICO 0 June 21 Continental Shelf 2 May 30 arch 23 U) 50 Miles Species diversitie's in Zooplankton (species per thousand individuals) from the western ,;nd of Corpus Christi Harbor to a station 25 miles out on the shelf of the Gulf of Mexico off Port Aransas. Fig. 8. Diminished diversity in the mixing zone of bay and shelf through jetties in Texas (Odum, Guzon, Boyers, and Allbaugh, 1963). SECCHI DISC READINO A PHOTOSYNTHESIS MIKLY V RESPIRATION E "ATURE _J 11 JAN- MAR MAY JUL SEP Nov JAN- MAR MAY JUL SEP Nov Secchi disc reading, salinity, and water @Gross photosynthesis and respiration at temperature. four light levels. Fig. 9AL. Characteristics of waterphytoplankton, and productivity Ili Beaufort Inlet, N.C. (Williams and 1,1@rdoch, *1966d). DID a - TOTAL PLANKTON D, - NANNOPLAWT Z @02 E 10. CLORO 20 PHOTOSYN. I 5. 10 o JAN- MAR MAY JUL SEP NOV a. Gross photosynthesis at surface illu- mination and respiration of total plankton and of nannoplankton alone. b. Chlorophyll a coneentra- PHYLL tion and the ratio of the average rate of gross photosynthesis during the daylight hours at surface illumination to chlorophyll a concentration. 0 5 mi N 26o Newport N o r t h River River co C:) MOREHEAD CIT@@) 0 U n d---!9 Q) 04 oque Ban Bea art k so, Inlet Bogue Shackleford Banks Inlet Cape Lookout -Index Map. Ruled area rhows location of region covered by figures X. ................ ...... . ........... . ................ j ............. ................... ............ ...... ........... ............. .......... .......... .................. shelly(>5%) medium (F-M-C) sand sheliy fine(VF-F-M) sand fine W-F-M) sand -Gross lithology of Beaufort Inlet F-t9e'9B* Sediment charaCteristics in Beaufort Inlet, N.C. (Ingram, 1965). *(1561 'PTOd) evxel '(.&Oq uOVOATOD) Avg ;"T Puv ssvl -IGAOTTOa * 11 '2TJ saftloAv uo pasuq aiu sam uy4osI -9961 'ounr ut AU Isra ui wallud uot -poldnow suotme ju .p Sl!uvlvS 'o @,v2t SSVd 113AO*lIOM ... ISM. I,- oz @@H-AAOI' 00 Ll 02 % 41 S 91 91 .00 (6961 *O*N '49TUT@JXDT"Vq- 3:0 S-Esuuvtlo UT @3UTL-rd uo sTew@uv 2w@;S 0 '36-2 Tu U'j -pioaaj q:)e;) jol uot ins atil altuBgsap saoads tlava Butmol -lo; s-iaquin,%l '5561 'I!jdV q2-.iql '@561 'Sep@ salpnis 2utl!d ;;ql woij pausuualap se 'Lutjojt@j quok; 'PolnEaq -s4d.(l wollo(l atli uo SUOTMOU PUT jv*sueozoXjq xuos jo spopod wqlanpozdaa suot .4vis a;).iql aLp jo stlop-ol ;)III til!.%% 'WHO.ItO tIVION lliojnrag JO AjU!:)jA @ljtlpalUW! 3qj jo depq L31NI imoinvae a 31XNHS sm Nye 313908 LAI, I'M aftoo! 'MA. 8 imozinV38 ,113 Gv3H3vbvl -4S 14 &0 9z .4 80 F 262 70 - 20 60 - 10 rEMPERATURE 5 1 1 1 1 40- MICRO C/O NA PROLIFERA RENIERA rual ERA PENNA RIA r I A R E L L A rVIOUL RIA C-ROCEA suG uL A NrRI r1NA SCHIZOPORELLA VNICORNIS srrELA PLICArA xw@ A104GULA MANHATTEWSIS PHAL4USIA HYGOMIANA PEROPHORA VIRIDIS H YO RO IDES HEYAGOWI S OSTREA V/ R G I N I C A c m r HA M AL U S F R A 6 1 L I S SALANUS IMPROVISUS eA4ANUS EBURNEVS i F A M i J I A S 1 0 N (-)-a Beaufort, North Carolina. Fouling on wooden and glass surfaces February t942, by Ketchum el at. (ZO) Temperatures aye mean monthly values expo-l for short and long periods between February 1941 and February 1942, at Piver's Island, 1914-1928, from McDougall, after Gutsell. by M, I jougall (23), and on glass panels one month between November 1940 and Fig. 10. 3easonal patterns of set of attached animals near Beaufort Inlet, North Carolina (Woods Hole Oceanographic Institution, 1952a). 263 GULF OF MAINE 14 WOO 03 HOLE AREA NEW YORIC AREA +"Oil, OLK AREA 0 it 10. Q 0- 0 o ALGAE z x 0 @0 - 7Z' -DIA rOMS I: h X cc CILIA TES 0 A* i L AGEL L A YS M 0 120 130 0 100 200 300 400 500 600 TIME IN DAYS EXPOSURE - MONTH-DEGREES Temporal sequence of bacteria, algae, and protozoa in the Weight of mussel fouling related to month-degrees of exposure. Slime film developing on a surface immersed in the sea. After Hutchins and Deevey (M. Fig.-12. Early succession (Woods 'Hole F .ig. 13. Growth on surfaces as a function oceanographic Institution, 1952a). of time and temperature (Woods H le oceanographic institution, 1952af'.1 340' 300. 280. 260, 240' 2ZOI 9 ZOO. m ISO ILI CL ISO- MW 140. 03 120- z too, So. 60- 40 20 10 0 N 0 j F M A M J :i A J J A I - 1945 1946 Numbe@s of barnacles attaching to test panels exposed at Miami Beach during Successive years. A fresh panel was immersed every 15 days and was examined after one month's exposure. The solid area represents Balanus eburnems; the clear area, Balanus amphilrite; and the hatched area, Balasus impievisus. After Weiss (42). Fig. 14. Seasonal record of new barnacle attachment in Miami Beach waters before modern eutrophication (Woods Hole Oceanographic institution, 1952a). Table 2. Estimated Yearly Accumulation of Mussel Fouling 31can Y@arly Month- Estimated Location Temperature degrees Fording *F per Year lbs.1sq.ft.1yr. Mount Desert Rock 44.7 152 2.72 Boston Lightship 48.3 196- 3.55 Fire -Island Lightship 52.9 251 .4.61 0 .x x. Winter Quarter Lightship 57.5 306 5.65 (Woods Hole Oceanographic Institution, 1952h). 264 there is light) and associated small animals all in less than two weeks. With timing apparently correlated with availability of food to the new stocks, larval releases provide the "set" to start the attached animals. As shown in Fig. 14 at Miami and Fig. 15 in San Diego where the light regime is not varying so sharply, as in N.C., the regime to support the reef organisms and their reproduction is fairly even as is the set and growth. There is some minimum in winter when the light energy to the food chain is less. Contrast the more southern steady patterns with the sharp season in the northern waters of Maine and elsewhere where reproductive activity seems to be timea with the spring-summer blooms of plankton and runoff from melting snows (Fig. 16). In Fig. 13 the growth is related to product of months and degrees suggesting a role for temperature. However, the temperature is following the light energy input to the food chain with a small lag as heat acciiMilates,thus keeping pace with the accumulation of energy in the food chain which also lags. The sharp changesof monsoon regimes in India have a substitution of species in the reproduction program, but there is some activity continually (Fig- 17)- Bottoms of Moving Ships Much studied by the Navy are the fouling conmunities on the bottoms of ships in spite of the toxic paints applied to prevent the growth. Examples are given in Fig. 18. STRESS DRAINS Current Factor Studies relating the growth of particular fouling species to current show optima as in Figs. 4 and 19. When current is low, the species does not receive enough food and aeration for its internal metabolic setting. When currents are very high the stress of attachment, feeding, and maintenance diminishes the amount of biological structure that can be maintained. Chemical Stress Whether chemicals axe in the surface material or diffusing in the water, they serve as a stress, require special adaptationsp and simplify the variety of the ecosystem which develops and the amount of biotic organization required. The,grovths on bottoms of ships in spite of anti-fouling paints and harbor pollutants are a good example of the system that results with addition of a nnn-made chemical stress in addition to the high current stress. An example of copper toxicity diffusing in a gradient so as to limit the high current ecosystem is given in Fig. 18. As stress increases, processes requiring excess energies such as growth and reproduction stop and ultimately there is a concentration at which energy available to the organisms is less than that needed to deal with the stress. Temperature The size of the members of the fouling communities may vary with temper- ature. It may be that the food niches may be occupied by smaller units of biological machinery at higher temperature because the biochemical processes per SAN DIEGO 70. 265 -20 F oc -15 TEMPERATUPE 60 CC rO CA RP11 S, r & 8 1/ 4 A R 1.4 'C R-0 CC A 8 U G e14 A NZERITINA C/o IV AIsresrINALIS EUPOMArus C A'N U 5 T INT N N A 8Ult UM -800 WET WEIGHT -600 -400 -200 -0 i F M A M J J A S 0 N D San Diego, California. Fouling of glass and concrete surfaces ex- developed per month per square f t of surface. Temperatures: mean monthly Posed One month, February 1939 to April 1943. (Brku,) Wet weight of fouling values at exposure site 1941-1942.oAofter WhM@n (44, 4g). Fig. 15. Seasonal record of larval set and accumulated grovth in a 'sub- tronical area. (Woods Hole oceanographic Institution., 195,%). 20 F 60 @MPERA @@UP @E LAMOINE -t5 266 oc F .110 50 .5 TEMPERATURE 40- CLADOPHORA RUPESTRIS 0 8 E L I A rUBULARIA CROCEA ENCRUSTING BRVOZOA Mob- SPIRORBIS SPIROROfs AfVrILUS EDULIS BALANUS CRENArus B A L ANUS BALAN01,94ES j F M A M I J J I A S 1 0 N 0 Lamoine, 'Maine. Fouling an short and long term exposures of collectors, May to October, 19+1, and 1944. Temperature as obser@ved at site. After Fuller (11). Fig. 16. Seasonal record of larval set in an Atlantic north temperate location (Woods Hole Oceanographic Institution, 1952 a). J F - IT J F M A M J J A ANIMAL A M J J AISJOINIDI S 1 0 1 N 0 mF L--1-j TE@PE14ATI]IRE, F A011ED-A .LAOIIEDF 86 HyDROIDES. 84 ttARPHYSA- 83 PLATYtAERE15- 81 CRII51A. 0 OSTREA. 79 MYTILU3. BALANUS. RAINFALL- INCHES 14' A CLIBA[.4ARTU5 12 3ALMACIS. 10 I V POLYCARPA. DILMDROCARPA. ACENMOGoaius. 4 I@ j CLUPEIDS@ .2 TNZRAPON. I-N.E @'X-S.W MONSOON -X-N. E@ Seasonal variation in temperature of sea water and in rain fall at 'Madras, India. From data given by Paul. (Lejt) Seasonal variation in breeding of some marine wganisms at Madras. After Paul (32). TEMPER, FWANIA L M _LAO"E,) PLO. Tye'"EIS Fig. 17. seasonal record of larval set in a tropical location with sharp change of Monsoon regimes (Woods Hole Oceanographic Institutions 1952 a.). On Fouling Resi OQ 0 0 0 0- @D 0 C'. 0 PI @77. C.) 0 m 03 0 0 0 Ea 8 0 . 0 OQ ZI " 0 91 I-h 3- 0 r =4 :r n 0 Ey, P - m C;@- tZ e@ w rA 0 -11 =- p w - @:,- -.-I- 0 @-m t-,:r 0 rt P" E. F-J 0 -3 n 2.m -- @; Z: q a r- CL W (D RL 0 f: rt Oq a. rt te C) m Ur CD F .0% (D 0 Ch Ib Ild CL 0 0 Mean Length Incremen C+ >1 P. 0 p p 4. tQ q 2. (A C+ 0 N C.I. . . . . . . . . . . . 0 0 0 -,Z"9 P- C) rt 4) 1, 0- - 0 0 0 0 0 0 = 0 0 0 :z 0 0 0 0 % m 0 g 0 0 0 0 0 0 14 268 13 - 12 - U1 I I t 10 - E of 7 & i@b6 E 5 I .714 3 2 0 0 1 2 3 4 5 6. 7 8 Section of panel 0.15 0.2 0.3 0.4 0.5 1.0 2.0 Average water vilocity, knots The effect of current on the growth of three species of barnacles, Balanus amphitrite (Circles), B. improvisus (squares), B. eburneus (triangles). (After Docchin and Smith, 1951.) 14 'A 2 - 10- 8- r Ew 6 E 4 E 2 - I- I I - I I .I I I &'-12345678 . Se@tioh of panel J 0.15 0.2 0.3 0.4 0.5 1.0 2.0 Average water @elocity, knots Rciation of the growth of the tryoz6an Schizoporclla unicomis to water 'Clocity. (After Doochin and Smith, 1951.) Fig. 19. Graphs of fouling growth as a function of curr' ent velocity. 269 graxa may operate faster. Also, at high temperature there is more cost of maintenance program due to thermal degradation that occurs in all structure and must be replaced or repaired. The high velocity ecosystems are important to man as concentrating mechanisms for food, sports, for waste purification, and as@problemB in main- taining ships, cooling pipes, and inlets. Those finding the growths as useful yields need to collaborate with those who find them detrimental. Some more general calibration of potential yields as a function of water current my help planning in the future. The high current system forms as a subsystem in many bays where complexities in current create coarse grained bottoms, shell substrates, epifaunas like small micro-reefs. The associations of high current animals and coarse and shelly bottom substrates in Buzzards Bay,, Massachusetts are shown in'Figs. 20 and 21. 270 41' 42' 4. 52. Fig, 20. Northwest Buzzards Bay. 40- 9. Shaded areas indicate 24" 45' shell-rich substrates. 44- @0- I. Z5. 6' 20- 25' Depth in fathoms are 4, /4a circled, and station 15. numbers are shown in 15. 14 italics 3V Nautical Mlle 31V 70-4.6,-- 4'e 4Y !J SHELL-RICH SUBSTRATES SHELL-POOR SUBSTRATES <5% >5 % <5% >5% 100- silt-clay Silt-Clay Silt-Clay Silt-Clay 90. W so Q 70 Ir 60 50. W 40. 230 W _0 10. 0 b 'b lb QL 1b Q, Z 't QL Ck , . q ZZ 0 0 It. 'b 4? Z. GX Ck Q, QL QL ka Fig* 21. Bottom animals in Buzzards Bay, Hass. Larger quantities are associated with higher energy envirorments especially where shell surfaces permit organisms to project above still water of the sea floor (Driscoll, t967). 271 Chapter A-4 OSCILLATING TEMPERATURE CHANNELS AND CANALS In a few places in the United States there are regions bathed with frequently changing waters of wide temperature difference to which few organisms are adapted and in which adapting ecosystems must divert energies from community organization to physiological adaptation., More such situations may develop with more heated water released from power plants and with plans under consideration for navigation channels joining waters of.widely differ- ing temperatures. Existing examples of oscillating temperature regime MY show the kinds of ecological systems that may adapt. Examples Cape Cod Canal As shown in Fig. 1, the Cape Cod Canal at sea level joins colder waters of the Gulf of Maine with warmer marine waters of southern New England. There are several feet of tidal range on the south but a 10 foot range on the north which together pulse waters alternate.Ly :Erom the south and from the north through the channel so that tem t ,Lfera ure ranges may go as high as 27 degrees Fahrenheit. From Anraku (1964a are shown patterns of salinity (Fig. 2) and distributionsof principal zooplankton (Figs. 30 4, and 5)- Chlorophyll. data as an index to phytoplankton activity ere shown in Table 1. A plankton system is nain- tained in the canal by the injections of new water. Pseudodiaptomus was more common in the colder waters., Labidocera aestiva in the warmer waters and Acar- tia :tgpsa and A.. clausii covered the range. Fairbanks, Collings., and Sides 79-68) i7n an ab-str-actdescribe winter flounder,, pollockscod., tautog,,silver- sides, and herring as principal fishes. Fish eggs in the plankton were of these -species and also CE cunner.. mackeral, rockling and sand lance. Shipworms boring in wood panels increase to the west. Nektonic animals and plankton capable of moving with waters retained some diversity but attached organisms along the shores, stressed by changing temperatures,,vere low in vaxiety. Frame (1968) found a quasi-steady state of the green algae Ulva, Enteromorpha., and of the tunicate Molgula on the temperature stressed sh s. Power plants in the canal may ada additional oscillations in temperature. Chlorophyll (Table 1) data show a productive system maintained in the mixing. New Panama Canals Very controversial is the proposed sea level Panama Canal which has some properties in common with the Massachusetts sea level 'Canal. South of Panama there are 20-foot tides, variable salinities due to heavy runoff, and 272 CAPE COD BAY A14 N A12 c,00 VINEYARD SOUND Location of standard stations 1-13) occupied on the section Buzzards Bay-Cape Cod Canal-Cape Cod Bay. (Station 14 Was occupied only occasionally.) The largest streams, the %%leweantic and Wareham rivers, enter to the northwest of Station 28. These presumably account for fresher water between Cape Cod Bay water and Buzzards Bay water. Fig. 1. M!Lp showing Cape Cod Canal (Anraku 1964a) TABLE I lifean chlorophyll a (mg1ve) in each water mass Date Bu=ards Bay "Cane' Cape Cod Bay water water water 19 Sept 1960 7.8 4.3 5.5 15 Dec 1960 2.7 2.3 2.4 5 July 1961 2.4 2.9 0.7 Aug 1961 2.4 1.3 0.8 (From Anraku 1964a). 273 a BUZZARDS SAY STON YPOINTDIKE CANAL PROPER CAPECODBAY ST. I ST. 2ST. 3 ST.4 SXS Ste St? Ste Ste Stio SVI ST.12 Sx.1 0 Z2 N to 2.1 % ---------------- '20_ 46. Z' 41 @v 13 EST 1615 it 5 @7, TIDAL CURRE EAST 95 NT TU@S 32.00 0------- 0- _c --NEAR oor@ow 31.00 SURFACE ------- 30.0 1 1 A@ A- -1 j 0 24 6 1, 10 12 14 16 'a 2 0 22 SCALEINMILES BUZZARDS SAY STONYPOINTDIKE f__ CANAL PROPER CAPECOOSAY ST. I ST. 2St3 ST. 4 ST. 5 Ste S" Ste Sr.9 Stm ST f) ST. 12 57.13 0 5 W < F.67 7.6 za 7.4 7.3 Z2 &I ej 8.3 <8.33 X z to. Z r L CL 5 rr@r@ F , DECEMBER 1 1959 ST 925 DAL CURRE@T TURNS f*E :01 T, JEAST ,1550, 32.00 :@All 80T T011 31.00 - SURFACE 30.0 -L L_ L L _L_ L 0 24 6 8 -0 12 .1 .1 11 20 ag SCALEINMILES c BUZZARDS BAY STONYPOINrDIKE f___ CANAL PROPER CAPECODBAY Sri ST.2 ST.3 ST4 SKS Ste Sty Ste Ste Sro Sri$ ST.12 Sr.13 0---- ---- ------- --- @- 5- ----- 11 _.@" L 1 ; :: !r: ; `.e L'i .4.8 "S.0 5'.15.0 :4..2: 4., 1 , - : - "4. 4.1 4.3 > 0 >4.ff _Z@ 0. APRIL 11, 1960 EST 844 RENT TURNS 32.00 31.00 - - - - - - - NEAR BOTTOM 0 tz 30.00- 0 j 29,00 Its-00 L I- I- L 24 6 8 .0 12 1. 16 .1 20 22 SCALE IN MILES 71 - z Fig. 2. Salinity patterns in the Cape Cod Canal (Anraku.,1964a). ACARTIA TONSA 274 7. Distribution of Acartin tonsa through- out the y"r at each station, plotted on logarithmic scale. Figures indicate the number of 'individuals per m3 taken with a No. 2 net. Ranges of Cape Cod Bay water and Buzzards Bay water are in- dicated by the stippled and solid line, respectively. LA8100CERA AESTM oo@ 3 4 Distribution of Labidocera aestiva throughout the year at each station, plotted on lovarithmie scale. Figures indicate the number of i:idividuals per M3 taken with a No. 2 net. Ranges If Cape Cod Bay water and Buzzards Bay water are indicated by the stippled and solid line, respectively. 11-- ACARTIA CLAU51 Distribution of Acartia clausi through- Gut the year at each station, plotted on logarithmic -scale. Figures indicate.the number of individuals Per ma coUected with a No. 2 net. Ranges of Cape Cod Bay water and Buzzards Bay water are in- (licated by the stippled and solid line, respectively. (Anraku,1964a). Figl$, 3, 4,ard 5% Copepod distribution in the CaPe Cod Canal 275 colder iiaters due to upwelling part of the year. North of the isthmus tides are small and temperatures higher and salinities steady. Diversities are large to the north and small to the south. Discharge of freshwaters into the canalare predicted as lar&. In this 'feature the proposed canal resembles the Cross Florida canal which receives much freshwater from porous limestone aquifers so that there is a salinity gradient. Cross Florida Canal C. A* Willis., Florida Board of Conservationsupplied the following statement in 1968 about the west end of the new barge canal (Fig. 6) prior to the start of use by barges. "The canal itself.has,provided good trout., redfish., whiting., yellowtail and sheepshead fishing as the fish have sought this deeper water.during,the winter months. It has provided the only place on this section of the coast where people can fish for salt water fish from the bank. It has also produced a very good growth of oysters along the several miles of canal between Highway 19 Bridge and the edge of the Gulf@ This is attributed mostly to the proper sa- linity obtained by.the fresh-water in the limestone leaching into the salt water-flowing up from the Gulf. This short stretch of canal has produced thousands of bushels of oysters- both to the commercial harvester and to the fishing public. The newly exposed limestone rock along the banks has also provided a good cultch for the spat (small oysters) to catch and grow,on. It is not uncommon to find a thousand people fishing here on a Saturday or Sunday in the wintertime. The seven miles of islands created offshore as spoil banks have also provided a 6od feeding ground for mullet., big red- 90, fish and large trout. The small rocks along the beaches have provided shelter for hundreds of thousands of small crabs mostly small stoiie crabs and oyster crabs. This in turn has attracted and held the fish that feed on them -- blackfish., redfish,, sheepshead.. etc.- The islands themselves have provided nesting areas for many of our shore birds. It is easy to walk along the high spots and.. if you look very carefully., to find many nests of the Least Tern in the summertime." Suez Canal For species to displace others requires that the regimes of stress and rangesof temperature and salinity adaptation be similar. In the.Suez Canal in Egypt., the building of the Aswan dam is allowing higher and more regular salinities at the northern end which will allow invasions from 276 2 C7 2 2 22 4 Ciriankcet- *iZ1 4, 6 0 so -v..v Cr If 3 ;.-.a 0 "..0 A ... I- - - :"' .. ft jv C@ Yra.ket@tolllt E THR STACKS 4 32 0 A,- ;0?" .25 rr--3 C, 2 0 0 2 C, 4 4S is WITHLACCIOCHEE RIVER 10 A. The controlling depth at -11, d 4 water - 10 feet fo, a rn, 35 of 55 feet to t a. @___;v :5: . .....9 A.. 1961 IsI Mar 1960. F 11"I 'il 74"37 "33 3. 'Ort 14 7 5A'Q "36-1@ 1 " ". @Z .5 TS 34 P 2 74' .6 9 ';23A"2"30" "2 4 11 24" W "33" 2 IIn gg I i 29 2 1 re C -13" 8"17112... 22" Sff 3 41 `4 `3 T.9 G.P 3' "12 6 34 2 4 3 marsh 4 544 2 6" D- 1:,-@ 53 :@2 ofv Gerp 5 -t5 10 5 ghead Gop'i 8 Long Pi wooded s@arrtp C.@ 4'" 5 i 6 7 CRYSTAL RIVER 75 9 4 ENTRANCE CHANNEL 6 3 The controlling depth at mean 10, :5: to4 iiiiater as 6 feet for a midtn of 50 13 7 10 6 tt.3 2 feet. thence 4 feet to pier at to - of 6 &-d 2 Crystal Ri-r. May 19-0 8 7 4 7 10 9 3 5 4 11 13 _-e6 BI..k Pt 791285:8 3 Nc @' 7 2 3 3 4 e.4z@' 4 3 4 :5 -@5 to 7 9137 7 Platform 19, 15 3 13 3 91, Plaitf.;m . 3 k A - 7 7 74 L -7 5' "@2 Z7 13 10" ........ 12 WA8 7 16 13, 146 12'@!@ 16" 241, V 2 5,' A"4" 4, @@hell a2l 2 15 3, 2 2 4 -2 4 to 789 4 8 1" 2A" 8 15 j F1 4sec 16ft"lA":',) 7 3 2 R 3 2 r7' Cr _v 6 5 8 18 12 14 18 17 14 4 9 d'P SW'2" 7 7 6 hrV 10 817 15 66 5 25 3 77 ::6:: ::5 L-L -L-9-i-L I II L_1_L4_L 1.__L_L_ 45' 820 40' Fig- 6- Western end of the Cross Florida Barge Caml. 277 the Red Sea not possible before,even though there are some bypersaline conditions in the canal's middle section that reduce viable'transport. Thus the Suez example may not be a good model for predicting immigration in Panama. The properties of chan&g conditions likely to develop in the canal as-a continuing stress are likely to result in a simple commmity> with fewer species than at either end. Odum., Cuzon., Beyers and AlIbm.%gh (1963) found diminished species in Aransas Pass inlet where a similar stress of mixing occurs. Whereas such patterns are probably no barrier to the occasional injection of some species of one area into the zones of the other.. the presence of an Inhospbable system in between precludes much population pressure. The experience with the Cape Cod Canal shows that mere injection of species that are adapted to one temperature-salinity regime into a sharply different regime serves only as a minor organic food input* Representative of some opposition opinion is Briggs (1969) who believes there is danger of the canaUchanging large areas. This opinion is held by many systematists and evolutionary biologists who regard the historical factor as of controlling importance to the distribution of species 278 Chapter A-5 SEDIMENTARY DELTAS Bruce W. Nelson University of South Carolina Columbia, South Carolina nMODUCTION Deltas (Fig. 1-4) are.massive accumulations of sediment built up where rivers enter a lake.. an enclosed sea.. bay,, or lagoon., or the open ocean. Where deltas occur it is an indication that sediment is being supplied by the river at a more rapid rate than it can be removed by tidal currents., wave action.. and other forces in the basin of deposition. Thus the most significant stress., from the ecological viewpoint., is the high sedimentation rate that characterizes the-environment associated with deltas. Whether or not a river develops a delta is affected not only by its sediment load but by its discharge as well. Rivers that discharge less than 500 cubic feet/second are unable to counter- balance wave action. Those with discharges around 15.,000 cubic feet/second develop cuspate deltas without distributary channels. Discharges upwards of 50,000 cubic feet/second are needed to initiate and maintain the large dis- tributary systems that characterize the world's major deltas and to extend them quickly enough to overwhelm marine erosion. A characteristic ecological system develops in thewaters and on the bottom in the zones of river discharge into the sea. EXAMPLES Mississippi River Within the United States the best known and largest example is the Mississippi delta that dominates the state of Louisiana. In addition to the ecosystem at the mouths of the distributaries, there are other ecological systems and subsystems such as the oyster reefs., ma shes., and oigohaline bays., covered in other chapters. Maps and diagrams showing the Mississippi delta., some sedimentary characteristics., and some of the biological components and processes are given in Figs- 5-18- Zones and sediments are in Figs 5 and 6. Salinity in relation to current is given in A915.7 and 13., temperature in Fig. 8. Changes in temperature profiles after hurricane passage axe given by Stevenson (1966) in Fig. 16. The relative3,v restricted variety of organisms are summarized in Table 1 by Parker (1960) Foraminifers, are simma ized by waiton (1964) in Fig. 14 and Curtis (1960) in Fig. 15. Ratios of sand., silt., and clay are given in Fig$ 17 and 18. Ahasco River, Western Puerto Rico The delta of a very small tropical river in western Puerto Rico is of special interest because of the trace element studies and the environment of blue tropical waters and coral reefs. The Anasco River and some properties of sediments are given in Fig$ 19-30 (Lowman 1966, Lowman et al.1966, Lowman et al.1967). 279 34 3. 32* .................................... 3..0;41 ............. _4 .............................. W .............. . ....................... ................... ....... .............. *-.-`-`-'-@*,@.@ z .... ............. ....... ................ ....................... ..................... ............ ....... .... .... ............. ..... ............. ...... . . ..... ................................ ................. in meters`."-..-*`.'. .... ...... .....................I.................. 3X .... ..................................... ................. .. ..................... . ...... . ...................................................... .......... ................. ............................. . .......... -....... ..... ................ .... ......... ..... ......... .... .............. ... ......... .................. ..... .................. .............. .............. .......................... 3 V 32' . ........... Figure 1A ................ . ....... .... ........................... . ..... . ............... ......................... ... ................. 0 0 0 0 !, 0 2 .................. . ............... .. ......... V ........... . .......... . ......... . . .................... . ...... ..... .......... ......................... . .. I....... 0 00. .................. :....... ......... .............. .............I............ ........................... . . . . . . . . . . .................. .................................... ... .. . ... . . .................... 30' . .. . . .... . ...... ...... 30 ............ ...................... ............... =............ ..................... .............. ................... .... ......... .......... ....................................................... . ........ ....... ....... ... ....... .. ........ .......... ................. ................. ................... 2 9@F- 29* 32* 31* 30* I Subaqueous lopset plain Shore C Sealevel Suboerial topset Plain 01 e\\o Figur6 1B The Nile Delta. Map: subaerial part of delta shown by darker shading, subaqueous part by subm (depth% in meters). Cross sections: profile A along 31st meridian in center of delta-shading shows probable thic sediment (upper section exaggerated about 80 times; lower section nearly true scale); profile B along 29th me delta. EL_ DELTA(iD D E LTA (A) 280 0 INE, I 5=ci I N, I �R - [;@JDESTRXTION E SITS CROSS SECTION Figure 2 OF TOPSET BEDS FORESET BEDS Ej BOTMXSET IMBRICATING DELTAS -Shows schematically the vertical relations between constructional and destructional deposits in imbricating deltas. Stratigraphic units of successive deltas merge, and may appear correlative over wide areas. Thicknesses of individual deltas depend on depths of water when deposition begins. Amqas,?xi CIty 4 20 60 Ka 140 0 40 Figure 3 'IX Sft,flycj, rt Fuse City OSaA-a City Osaka /60 Bay 12 /00 80 60 20 Kilonietres L L-1 EQUAL LINES OF LAND SUBrIDENCE IN OSAKA CITY, FROM 1935 TC, 1960. (IN CENTIMETERS) DISTRIBUTARY 111STR UTA_RY__j C@!B Ch I INTERDISrRIBUTARY P..d Ma,sh 'OtTS & C@YSI -0-Ra 01, 1. k. Figure 4 Ab-d ... J ESTUARINE Ch., -I INTERDISTRIBUTA By 5 -t: su sit E E- rREATF DENCE Effects of deltaic subsilence during distributary system abandonment. 281 aq-oc@ 99-40' ........... 29. 20, '\35fOth'- 14 0 2 4 G 8 10- 12 14 16 Figure 5 STATUTF MILES 00 INTERDISTRIBUTARY BAY@ TOPSET BEDS DELTA FRONT PLATFORMJ FORESET BEDS =86TTOMSET BEDS OPEN LAGOONAL INLET OLD SHELF DEPOSITS Im. REWORKED MISSISSIPPI. DELTA __ZFOR@SET TOPSE T @ i -PLATFORM-- ELTA TOPSET _.S- SEA LEVEL B FORiS@@T' OOTTOMS@T -Sediment environments to the east of lower 'Mississippi Delta, Relation of these environments fore-set, and bottom-set beds is indicated by comparison with the inset at the lower part of The slope of the fore-set beds is greatly exaggerated, ictually does not exceed 1 per cent. From :"4. Fig. 9. 9t, 9@- 65. '0 30, 'A; 5 25' 10* X_ Figure 8 ... . .... . .. @"7 -Difference in surface temperatures in *F between warmest and coldest months. After Fuglister, 1947. 282 4 as' soov ST a Ists" .;el Iz so. A Is' TOPOGRAPHY OFF THE OUTER MISSISSIPPI DELTA 1940 JI o- CONIft. Al't-1 Fool Is w Ps so- Wo. -Submarine gullies which are concentrated off the most advanced passes of the Mississippi Delta. From Shepard, 1955, pl. 1. Figure 6 MODERATELY HIGH RIVER STAGE LOW RIVER STAGE j-11 II.Ioss, WE- als@ ... Go 4T o.- -.3. SEPT-E. It. mw;fjvo WC,UIIISE AT. WIN ROUGE, "'Awc.ft TIDE Kes.." 2.3 - "T .. ...... . TIDE E811114s, 1-2 .0u.. 60P.4. N.x..- Eas L ----------- !LQ 504 SURFACE CURRENTS I.RFA-CE CURRENTS b t 'STAKE SEA- FR*W LA3T LA.. MITANCE SE-AD FRI). L.ST I.A.01AUt-Ell - U) . Is -"to 2.5 so -34- o D 8-.15 23 ..22 so so No.l. Is. %IWITm R to - PROFILES OF ------------- so PROFILES OF CURRENT AND CHLORINTY CURREN T AND CHLORINITY So so P So LEGEND 4.VZTT -FILE CNLARNIT (Asn" oEft @$.w Profile showing current velocity and chlorinity, at the mouth of North Pass, Mississippi River Delta. Upper diagrams show surface speeds along channel axis. Diagrams on the left show the outward flow during moder- ately high river stage extending to t he bottom at the bar. Salt water included during the preceding high tide is rapidly flushed out during the ebb. Profiles at right show the lower river stage: the current is not affected by the bar, the water rides over the salt wedge, and the speed decreases smoothly in the channel and over the bar (From Scruton, 1960;L Shepard, 1960). Figure 7 (tr96-1 Ou'gT*ESVD PU'8 Ulmxa-100 MO-Ta) -xaTdmoo sq-Tap jo T9POM VaDT@01t4-Odtq JO UOP-Das SSO-ZO *.9Ta - - - - - - - - - - - - 00 - - - - - - CV - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- -- - - - - - - - - - :)uap!sqn LTI - - - - --- - - - - - - - - - - - - - --- - - - - - - - - - - - - - .. .......... ..................- ............ .... .. ... ........... . ....... ..... .:.,. ....... ...... 0j, . .... .. .. ..... . .. ... Weeig 1098 JaISAO 3uap!sqn Epoeo - - - - - - - - - - - - - - - - - - - - - - - 3NIWW- .-MOIIVHS..-, an - - - - - - - - Japlo, =@@-ejjqpo L U 0 j I Is.pues 7 qSjeW io4nq!j4i iv Jals 0 89,20, 89*00, N 284 M@\\ 29' 30' 1 2 3 4 5 6 30 NAUTICAL MILES Figure 10 FAUNAL ASSEMBLAGES MARSH INTERDISTRIBUTARY BAY FLUVIAL MARINE 29* Fn DELTAIC MARINE SOUND OPEN SHELF 89,00, -Foraminiferal facies, southeast Mississippi Delta. Black dots are station locations. After Lankford, !959. 1922 1958 From c or E.QuadranLlr From -W ph.tognphs hra. &'-W phm,.graph, N-1 Air Suvi= Figure 11 THE JUMP THE JUMP z@ HEAD OF PASSES HEAD OF PASSES 0 '3 MILES 0 3 z MILES Ca, to Sect., CFA LSLI Ca,to.Sed,CSILSU The junip ('West Bay) subdelta near beigh,tof The Jurnp (West Bay) subdelta showing sub- depositional activity. sidence effects during present process of abandonment. r sy 1111970% SOUND 285 2031f* #$LAND >4 2V 3W '30, 2 . . . . . . . . . ...... Figure 12 2W. HIGH DISCHARCEi SPRING.1952 a 4i 4 6 8 1 kAUT1 Well -Di%tribution of suspended matter in surface waters of inshore area, from secchl disc observations. Compare with distribution of Surface chlorinity T %NtTOW SOUND BOTTOM Figure 13 to 0 5 10 NAUTICAL MILES CHLORINITY IN PARTS PER THOUSANO .0 DEPTHIN FATHOMS _W f W -Inshore chlorinity distribution, Spring, 19S2, high river discharge, low winds. Bottom chart is maximum observed chlorinities, usually occurring here on flood tide. Surface chart is com- p te of minimum observed chlorinities. These usuallv occur on dood tide in Breton Sound and ebb osi tide east ofMain Pass. Chlorinity changes are most pronounced in areas marked "variations" and changes were toward higher chlorinities. These charts show maximum observed vertical chlorinity differences. Per cent occurrence of dominant species w 4@ C3, 0 (a C+ 0 0 0 C> 0 x VMWAP U11 "-;'0 0 0 0 0 003 VD 0 330 0 C+ w !71 I-k tV@ \x 0 aL IN C+ 23 IT 7,11 C+ 0 tU. CRY M\W, 005 M \UM YA@ 99Z Table 1. Missisippi Delta animals (Parker, 1960). 111. DELTA-FRONT DISTRIBUTARY AND INTERIDISTIUBUTARY ASSEMBLACE 287 Specki Comparative Abun;fance; Size PELECYPODS Rangia cuneata (Gray, 1831) Not as abundant as in river-influenced assemblage Rangia flexuosa (Conrad, 180) More abundant, especially in interdistn'butary. bays Macoma mitcheUi Dail, 189S Rare, mostly in channels Crassostrea virginica (Gmelin, 1701) Very abundant in @higher salinity interdistributary Joetricola pholadiformis Lamarck, 1818 bays; large. (2-6 in.) Common on distributary submerged levees; medium GASTROPODS -(ly2-23/2 in.) Littoridina or Amnicola, species Not very common; small Ms in.) I b d Echinocytherels. MOrgarefifera Cushmonidea cf C. agricolo BIOFACIES DISTRIBUTION o Krithe producta OF , .11 _" Hernicythere cf. H. convexo SELECTED OSTRACOD SPECIES _n Cytheropteron off. C. alaturn Cytheropteron cf. C. leonensis Basslerites cf. B. berchoni ABUNDANCE DISTRIBUTION Paracypois Polito -no. Consistent (higher Percentages) Pterygocythere sp. --.m ErrOliC (higher percentages) 0 Microxestoleberis sp. Consistent (lower percentages) Sohnia sp. Errotic (lower percentages) Z Cytherello Iota Rare AM Xestoleberis parva Pseudocythere? frogilis Parocytherols ensiformis Mochoeriho tenuissirno Cytherura? cf. C. ocuticostoto Buntonia sp. M Occultocythereis? sp. Ptery,gocythereis cf. P ornericano 0 Argilloedia Icylindrica Cylherello, Polito rn 'Argillo6cio Minor Cytheropteron laturn U) Trachyleberis sp. Loxoconcho cf L. purisubrhomboidea, Pellucistorno off. P howei Cytheretto doniono Cytherura forulata Cushmonidea cf. C. echolsoe Loxoconcha oustrolis Cushmanidea cf C onderseni Luvulo cf. L polmerae Compylocythere loevissirno Herrnonio?.sp. Z Perissocyiheridea brochyformo - Microcythere moresiono Cytherura raro - Laxoconcho subrhomboidea - Hoplocytherideo cf. H waltonensis - Cytheruro sp. Xestaleberis curta Puriono cf Pmesocostalis Puriono dowsoni Microcythere cf. M.'stephensoni Leptocythere porocastoneo Fiernicythere cf. H.cyrnbo 'o Leplocythere bccescoi Microcythere johnsoni rn Hop ocytherideo bossleri Cl) Hop! oc ytheridea cf. H. ponderoso Mlicrocytherura? sp. Actinocythereis cf. A. exonthernato M Leptocythere cf. L. porcellonea Cytheruro forulato var. Candono morchica .,and C. spp. 'Paroc@therideo [email protected] Perissocytherideo* Matsoni -biofacies distribution of selected ostracod species. (Areal distribution of biofacies units is shown mi Figure 1.) Bio,facies units: 1, offshore (middle and outer neritic, open shelf); 11, inshore (paralic); including Net nearshore (inner neritic, open shelf); Ilb, estuarine; ITc, open lagoonal; 11d, interdistributary. Fig. 15. Life zones formed by ostracod distributions in the Missisippi delta (Curtis, 1960). 288 WSY ---------- 17 oil a-.- --Temper2ture profiles seaward from !be Mississippi Delta from data ga&.ered frorr. the M/V qLLILTI and R/V Alamino& 940 920 --go* ago W. 7- 300-./ j'@ 6VL r or r rfco sc n le it 25 - - - - - ------------- ..Q it E 44 E 25 E 20 c 2? SArAIAFNA 9AY LWE W to E43 3Q to Its- -71 Z& 22 '21 5c, E45 E 2. 22 .rPRMN4E "Y 1.114 L_ _E.6 NFAR-S@40FIC STATIONS oFFS,40PE STATIONS -Temperatiare. tr2res of the waters --ff tb? MissIzsippi Delta before and after Nurzrlc@,roe Betsy. The ldownwelling" of waj,.-m surfice watert; is noted in depths gribater uhan 50 m. Fig. t6. Vertical temperature graphs off the Missisippi dolta (Stevenson, 1966). too- @EY 289 T go-..S-!E 89-04 WO. 02' 2 10Y .N:. TO D., E % 50-: .0 40 20 E 40 A L L '0 30- T -5 2 so U A S 10 W 0 0 C E - 0 - 30- 0 L\ S 20- 806 807 804 8 8@' '0 12 610 504' \A to-\y f 12 '.0 60 129 w -617 I A 691 546 Z 1 42 12 20 692 10 0 129, 3 9 694 '690 9 696 EET L 1 6 9 L: 0 lk 679 P4 SS 68 D -59 _n r 77 20 n' 2C CONTOUFM W Fu-r 8 802 887 886 881 885 883 61 '---684 J A.M. 89'C4 89-02' 89-00* es-5e -Sand-silt-clay content (left) and per cent of major constituents in the coarse fraction (right) from sampies axound the mouths of North Pass and Pass a Loutre, and in an interdistributary bay (Samples 801, 802). All samples except those on levees taken during low water. From Shepard, 1956a, Fig. 36. .Fig. 17. Sedimentary characteristics in the,l'iissisippi delta (Shepard, 1960). MISSISSIPPI 0 ____DEP H- 100 200 SAND FEET L SILT 50 100% 0 5 NAUTICAL MILES J.R.M. -Bottom profiles and sand, silt, and clay contents of sediments off major Mississippi (North Pass) and Rhone (Grand Rhone) distributaries. Sample loca- tions are plotted horizontally from delta (left) to offshore shelf (right). Data from Shepard, 1956a, and Kruit, 1955. Fig. 18. Sedimentar'Y-profiles of the i'lissisippi delta J W 0 EM 0 G A C A [2. Y 0 97 FD 0 0 0 C: 14, ca LO \0 r+ 01, CN 0 LA eD 0 00 VO -lie ol Ica Ir 00 C+ I.- CD 0a, 0Z5 0> 00 )-h 06Z -------L DEPTH IN FATHOMS 291 0 2 NAUTICAL &%.ES 0 SAMPLE STATION 5 5 65, w" 0 tVER -.00 ANAS % DELTA SEDIMENTS OD MA1NiCHAS**'**'***.'- S-:*"-, HYBRID, SHELF @'o SEDWIENTS E S EXI I@RIOR . .. .. -55-NEDIAN DtAMETER 4.5 670 11!500* 67*11 2'30" 67*12'00' 0- so too- WTTOM PROFILE CNISHORE-OFFSHCRIE TRAK@ECT ARASCO SAY 4W- dw- OMYA CL&Fy 24T. 700 1WVr' UND (CAPOONATEI - JIM- IMLCT SAM AM CAAIEUY SANa SASN QArY SCT 162W a 3 NAUTICAL MILES Edo prof ile and bottom sediments o-, a 'O-"ne due esast from the Aflasco River Mouth. Fig. 20. Sea:Lmentary patterns of the Ahasco River delta, Puerto Rico (Lowman, Phelps, Ting, et. al., 1967). CLAY 292 DEPTH 'N FAI HWAS %mn 9LT I4rii, @j 0- r NAIJTKAL NALES Mo. LO N 0' q 400 90 A Fig.21. Sedimentary Facies- of Mayaguez and Aflasco Bays based on sand-silt--clay percentages. (Lowman, Phelps, Ting, et. al.,1967). 293 It NIGHT COPEPODS 200-- ISO- W DAY COPEPODS z 100-- 50- OTHERN 4":.P -O`TH R COPE ODS 0 0 0 UM 10 to 0 Q Qj N W 0 0 0 0 HOUR .[..lg. 22. Abundance of the more-numerically Important copepode whose maximum concentrations occurred in the day or night plus all other copepods and total zooplankton, other than copepods, are plotted at hour sampled. (Lowman, Phelps, Ting, at. al., 1967). 294 Station D2-pth Riomass Mpfe/grUNTA12 1NtZn/gmD M";'tSc/FT-'1yt/*.k12 xmDfft.M2 1 251 1.70 7.7 310 2.9 0-es 4 251 4.53 17.6 470 5.2 1.4 2 2S1 3.91 6.4 540 4.0 1.1 6 -SO, 10.39 14. 150 6.8 1.3 11 7S1 16.4.1 6.4 9.2 4.9 0.1 7 so, 2.06 1.6 90 1.6 6.8 13 so, 2.38 7.0 110 2.9 O.So 12 so, 5.92 2.4 so 1.7 0.2 9 so, 4.44 8.8 8S S.0 0.50 10 so, 1-08 2.1 40 1.0 0.2 14 12S 1.93 13. 140 5.5 1.5 3 251 19.43 3.7 490 S.2 0.7 S 2S' 15.44 8.6 640 S.S 1.1 8 so, 12.70 4.6 30 5.3 0.2 PUNTA CAOENA 3 4( % Total biomass per X square meter in the top 8 centi- meters at 14 stations off the 1201 I Ariasco River (see'inset fig.).. %11 ARASCO RIV R Also sho,,4n are the total a%ounts 0% of iron, zinc, scandium and sama- 14 %6VL\ PLAYA GRANDE Tium incorporated into the benthic infauna. I ARASCO 130 04 SAY 010 % % t 05 0 STATIONS 2 LISTED IN PUNTA ALGARROB0 TABLE R MAYAGUEZ E Fig. 23. Distribution of biomass 4 trace elements off the Ailasco River delta of western P@erto Rico (Lowman, Phelps, Ting, and Lscalera, 1966). 295 MONA PASS El Pta. Borinquen 21 PUERTO RICO Sampling tation Desecheo Is. col, *117 Pto. Higuero 4 No. Cadena AloscO /sponge,,, ...... MAYAGUEZ 9 Copper /9 Nilro,en E )20,000 10,000- 20,000 0@ 01 % 5,00'D - lopoo % Lill 2,500 - 5,000 FFTTT-1 L Bahia de 1.000-2.500 Boquero % PUERTO RICO MONA PASS (1,000 L Fig. 24. Dist,,ribution Pattern of copper Per grar of nitrogen in nixed phyto- and zooplan@-Aon collected off the west coast of Puerto Rico (Lourman, P'helps, Ting, and. Lsealera, 1966). Mona Poss 296 E 2: 12: Pta. Borinquen Sampling Station N, PLO10 Rico eSOCheO 13. CO Pto. Codena OGICO MOAN" S,r/C* AM"n atift 1 10-4 )200 LO. 120-200 80-120 C3ZI=r= 40-CO 20-40 8CTjv= N 10-20 -Puerto Rica Mom Fims FBI Fig. 21 StrontiLzi/calciizn ratios in mixed phyto- and zooplafikton off the y west coast of Puerto Rico (Lowman, Phelps, Ting, and VE'scalera, 1966). Mono Pass 297 Ell Pta. Borinquen Puerto Rico De3echeo Is. Samp ng -rrTvm 1 91 to I FF MO. Hiquero -t-r 4- Pta. Cadeno An SCO kponge Vl- Mayaguez 0 pg Zn/g ash > 400 300-400 2: 275-300 Oah;o de Boqueron Puerto Rico Mono Pass L Fig. 26. Distribution pattern"of zinc per gram of ash in Thixed phyto- and zooplankton collected off th6west coast of Puerto Rico (Lowman, Phelps, Ting, and Esbalera, 1966). 298 Mona Poss E Pto. Borinquen Puerto Rico sampling Desecheo Is. Station Pta. Hisuero Pta. Ccdena 005CO I'sponge J MayogUrz 9 Cu/g ash )3000 0 400-3000 81 100-400 50-100 Bahia de (50 acqueron El Puerto Rico Mona Pass Fig. 2-7. Distribution pattern of copper per gram of ash in mixed phyto- and zooplankton collected off the west coast of Puerto Rico (Lowman, Phelps, Ting, and Lscalera, 1966). 299 MONA PASS IE Ptc. 13orinquen 21 PUERTO RICO Sampling Desechec Is. Station Pta. Hiquera Cadeno Ptc A-OscO 4- -114 MAYAGUEZ jug 'Iron/g Nitrogen >100,000 0: 50,000-100,000 20,000 - 50,00 r= L-1-1. I J J 10,000-20,000 M ITT 2,000-10,000 Bohia 500-2,000 do PUERTO RICO oqueron MONA PASS (500 Fig. 28. Distribution pattern of iron per gr'am Of nitTOpen in mixed phyt-o- and zooplankton collected at 37 stations during a 10 hour period off the west const,of Puerto Rico (Lowman, Phelps, Ting, and Lsealera, 1966). 6 6 5 5.. 0 300 W 4 4 0 061) 0' 0 2 00 0 0 20 30 40 0 20 40 so 100 mg SC/g dry sed;merit mo Fa/ 9 dry sediateist 0 0 0 0 V 200 200 0 400 400- 20 io' 40 40 60 so 100 rAo Sc g dry sedimint mg Fe/g dry iedim3n# Variation of scandium and iron with distance fiom the outflow of the Aiasco River and with sampling depth. 3- 6 Fe @9. Fe 6- 2- 15 15 0 5ortus. Reactor 18. 18. 21@ 21- St! 21- 24 24- 24 2 7@- 27 27- 33- 30 33 J@ 412 3- 33E 0 16 0 36 36 - 010 2\ 0 lDF20 30 0 10 20 3@ mg Fe z0a e asco River 'U Sc Sc. 6 Fe 6 6 6 6 9 C12. 12 12 - 12 Sc 15- So 15. 15 15- So' @9 "I 18 18- 18 x2l - 21 21- 21 4 24 @2 It. 24 24 27 27 7. 27 > 30 30 30 30 3,'5c 33 ?a 1133 33 - #3 ,36 1. .-- !11 1- 13 "@ 36 36 - A 010 20 30 40 50 60010 20 30 40 50 60 010 20 30 40 70 60 90 10 20 30 40 50 r milligracs of iron rnd micrograms of r-C4 iUU 67'35' 30' 25' 20' 15, 101 67*00, Fig. 5 @ 0 000 00 0 F, Fe I , r" Di.oribution oi ironand sc.;@iidiutn, with depth, in ruftrine :--ediinent!5 taken off the wcs,. co4Lst olPuertv Ifico. The arnounts ofiron :Md mtandiuni in the sediniellus wer6 inverse)y reiated to distance front shore. Fig. 29. Trace elements in the A'Ad-ir-o River delta (Lowman, Quinones. 7,11iro. Padovani, 2t il., 1966). AINALYSES OF NJAGNESJUAI, STRONTIUIV, CALCIUNI, ZINC, MCKEL, C1-TR0*M1U-AT, MAINGANTE'SU, MONT A ND 301 SCANDIUAI IN ISEDIMENTS TAKEN OFF THH'ASIASCO RINU1 WITH AIN O.T?.ANG*,-Pj:',FL GRAB Acrograms of t;emcno. per gram of r!ry sediment Sample No. Dq@Lb (maers) o,rLsliore Mg Sr ca Zn Ni Cr Mn Fe . SC 1 1.2 8 10,000 24 1,400 120 .52 55 710 44,000 215 2 1.4 22 - - - 140 56 65 4()0 Xsiooo 25 4 1.9 60 1 r), wo 110 2"000 150 65 57 IBM 48,000 19 5 2.0 65 17,C-00 110 19, CkT 1190 56 52 (60 51,0M - 7 2.9 190 14, M) w 44, 000 150 66 390 32, WO 20 9 3.3 V10 l5gy) 400 57,000 140 66 @4 400 .30,000 14 1S*23' 0 3- 3 OV 6 9 Z'i 9 9 12 12 12 Pta. 15 1 15 MZ;-jero oBonux Site 21 18 8 is .c 21 21 -,i 24 Hn 24 24 Ir 27 17 2 o 7 f 3 30 30 : e- Cr 3 33 33 6 ij 36 3 6 2 00 0 IC> C @0 0 0 0 10 C@ Y-Yagi5ez, 0 n 3 3 3 3 6 6 6 6 9 X 9 9 cr: An 12 12 C12 Cr 12 f - 1 15 15 i5 ..5 is Cr 18 - 1hi 16 18 .,21 - 21 21 21 24 Zn K, "24 - 24 L 24 7 w27 - A T-11 ft C a 27 .1 27 30 - 30 30 4, , w - i 5 )*k Z. 33 33 33 ,, L @ - 1 836 36 36 i6 L, ;J-, a 0CD ID 0 0 (D e:: @z0 C. 0 0 C11 1@:, I S 67%351 3'0 Al 1 gr, of elmnnt 1 01 5- 67 W. Distribution of inn)gariese, cbronii-Lirn. :trid wiiti depth, iii ni;irwe @CdiTn(@W,S tnk@-u off 4, lie wts, co@o@t of lluerf.0 Pieu. The levels of minganese in the sedirientR were o di,,tn r,ce fr?an flo. @;bore. Tlit-Iiirger finioniii-s of rii:vigariem,, zinc. chio- rnilin), ,vid iii(Ad irl @Fqnlplc- N'o. I I pr(II).-J.,13- relfle@!t ','w , ffeef, vf zi, @0,marjvc slide ul,@on 1 li(,. si@dirnerits in this urea. Fig. 30. Trace element distribution in sediment cores in the JinasCo River delta,'Puerto itico (LOWXan, Quinones, i%iro, Padovani, et. al.,1966). : LH-1 302 Other Examples Sedimentary deltas have a worldwide distribution. In many areas deltas are the sites of cities., harbors., or important agricultural lands.. so ,they have been studied extensively. In the United States deltaic regions are much more insulated from the main population. The small deltas of the Rio Grande.. Brazos., and Appalachicola rivers have been studied extensively., as have numerous small deltas that presently are building into the lagoons and estuaries of the Texas and Gulf Coast. Other deltas, more or less well known., are the Colorado River delta at the head of the Gulf of@California., the San jbaquin delta at the head of San Francisco Bay.. and the Fraser River Delta near Vancouver., British Columbia just beyond the United States boundaxy. There are several important deltas in-Alaska., including that of the Yukon and the K!uskoquim. The east coast United States has no active deltas., except some very small ones at the heads of estuaries that characterize this coast. Before the Santee River in South Carolina was diverted into Chaxleston harbor it was building a delta into the Atlantic Ocean and the cuspate form of the old Santee delta can be seen on maps of this region. Some famous deltas.in other parts of the world include those of the Mediterranean Sea--the Nile., the Po., and the Rhone. The Netherlands and Danish archipelago is built upon the deltaic system of the Rhine-Scheldt- Meuse system. In Africa the delta of the Niger has a classic form., and in South America the delta of the Orinoco in Venezuela has been much studied. Some of the great deltas of the world are found in Asia.. but these are less well known to westerners. Some important ones are the deltas of the Ganges and Irrawaddy in Indiap the Hwang Ho in China, and there are many others. The illustrations of deltaic envirorments that follow have been taken from the best studied of these deltas. DISCUSSION Deltas have a characteristic two dimensional form (such as that of the Nile shown in Figure la., from which the name "'delta" derives), a three dimen- sional structure (Figure 1b),, and a characteristic mode of evolution through time. When the supply of river borne sediment exceeds the rate of removal., deltas intrude upon normal estuarine or marine environments in the course of time. In this sense the sediment pollutes the environment, but this must be considered an expected outcome wherever the delta advances rapidly. If the -forces of marine erosion overcome those of sediment supply,, the fr6nt of the delta is cut back., beach deposits form along the shoreline., and the stage is set for a new phase of advance. Figure 2 shows the structure that results after two periods of advance interrupted by one of retreat. Because of the high sedimentation rate., the sediment that accumulates is very loose and con- tains large amounts of water. As the sediment consolidates., the surface of the delta sinks at rates that vary from 0*05 to 0-17 feet per year. This phenomenon poses special land use problems in deltaic areas. Figure 3 shows the magnitude of this problem in a heavily populated area in Japan. Subsi- dence also gives rise to special kinds of estuaries that exist on the surface 303 of the delta (see below). The water that is forced out of deltaic sediments during their compaction migrates to porous sand strata within the deltaic mass., produces remaxkable conditions of hydrostatic forces within the sub- surface., and generally causes unique problems of water supply and use in the area of the delta. The general form of shallow water deltas is shown.in Figure 1, The visible part of the Nile delta has a generally arcuate shape in two dimensions., both above sea level and below* Between Cairo and the sea the Nile River breaks up into a number of smaller branches., called distributaries. Each distributary consists of a river channel contained within two bordering levees. Between distributaries are extensive., low., marshy areas that are subject to extensive flooding.. both from the river and from the sea. Sub- .sidence produces interdistributary estuaries or bays in such areas (Figure 4). The profile across the Nile delta (Figure 1b) shows the various natural regions into which the delta can be subdivided. The subaerial topset 2]ain is constructed of freshwater river sediments., largely sands. subaguepus topset 22:@in-often referred to as the delta,front Platform--consists of predominantly sandy deposits constructed during the abrupt interaction between river and ocean currents that occurs at the very edge of the delta* The foreset slope. or,pro-delta plM. contains largely silty deposits that drop out when t1he'turbid river water flows out upon the sea and loses its' momentum. The foreset slope is a very gently incline surface with a slope of 0*3 to 1.0 per cent. Beyond the foreset slope is a very flat region in deep water where fine clays accumulate slowly. This is called the bottomset 21:ain. The Mississippi delta,is building into deep water,, rather t@ into a shallow sea,, and its surface form is quite unusual. Even so., the same natural regions have been recognized., as Figure 5 shows. The topset plain and the bottomset plain occupy the largest areas in a deltaJ, but about 75 per cent of the sediment deposition takes place on the narrowly restricted foreset slope, If, due to rapid sedimentation, the foreset slope builds out too rapidly and becomes over steepened (slopes greater than I per cent)., slumping occurs and sediment is moved en mass down the slope to the bottomset plain. Such activity gives rise to clZ@i=led topography along the foreset slope adjacent to active distributaries., such as appear in Figure 6. Such activity must be inimical to bottom dwelling life to an even greater degree than the high sedimentation rate and turbidity that characterize deltaic environments generally. The environments in front of an advancing delta are.estuarine in the sense that fresh and salt water mix in them., but they are a very special kind of estuarine environment. The transition between freshwater and sea water is more abrupt in marine deltas than in most estuarine environments. Where a delta protrudes into an enclosed bay or lagoon., the transition from fresh water to the water of the bay or lagoon is more abrupt than usual* The salinity of the bottom water immediately in front of a delta is nearly that of the adjoining sea or bay water, even though large volumes of fresh water flow out from the river at the surface, This is because the forces that tend to mix fresh and salt water (the tidal currents) normally are weak 304 in front of deltas. In fact, this factor is a major control on the occurrence and distribution of deltas. Where there are strong tidal forces., the sediment supplied by rivers is eroded and removed; where there are weak tidal forces., the sediment deposits and forms deltas. As a result of the weak mixing forcesJ, the vertical salinity gradient in front of a delta is very marked. Virtually fresh water flows out at the surface., and sensibly marine water intrudes along the bottom over the delta front platform and into the distributary channels. Organisms,that live on the bottom must be adapted to relatively saline water. The position of the leading edge of the saline water is determined by the hydrostatic force exerted by the freshwater flow. When the flow is low.. the saline water penetrates far up the distributary channels; when the freshwater flow is large., salt water is flushed out of the channels and across the delta front platform. From the ecological point of view.. this means that environ- ments in the distributary channels and on the delta front platform are subject to extreme salinity shocks that correlate with the freshwater discharge. The vertical distributions of salinity during a high and a low stage at the mouth of the Mississippi River are shown in Figure T. The intrusion and extrusion of salt water in the river channel at different stages show clearly. These diagrams also show the strong contrast between surface and bottom salinities. Of course, examples are known where deltas are building seaward in the face of strong tidal currents. The Rhine-Sdheldt delta complex in the Netherlands is an example. Here the deltaic distributary channels are much more typically estuarine in haring a salinity gradient that is stretched out along the bottom. The bottoms of such distributaries are less subject to extreme stresses due to salinity shocks. The distributary channels, the delta front platform,, and the pro-delta slope are all subject to extreme temperature shocks, by virtue of the fact that river water temperatures nearly always contrast strongly with that of ocean water. In temperate climates the high discharge period of the river brings very cold water to the delta margins,, since this discharge occurs in early spring. At other times of year and in other latitudes the thermal contrasts are not so severe. Figure 8 shows how the difference in surface water temperatures in the Gulf of Mexico region is greatest in the vicinity of the Mississippi delta and other sources of land drainage. The environments marginal to the delta are regions of high turbulence., another important stress that affects the indigenous fauna. Since water depths in the distributary channels and the delta front platform are small (20 feet or less), local wind waves or swells that approach from the sea stir the bottom. Strong currents from the river and those from the tides also sweep over these shallows creating a high degree of turbulence almost continuously. One of the effects of high turbulence is a conti=usly high oxygen supply in the surface waters. At depths below the surface and particularly on the bottom on the foreset slope, however, serious oxygen depletion can occur because of the high organic content of the sediment., the extreme vertical density stratification., and the relatively slow rate of water renewal from the sea source. On the other hand, beyond the foreset slope where the rate of supply or organic rich sediment is low, highly oxidizing conditions become re-established. 305 The freshwater discharge of the river brings both nutrients and suspended sediment to*the margin of the delta. In most deltas the quantity of freshwater discharged varies considerably seasonally. In temperate regions the maximum corresponds to the early spring runoff period. In mediterranean,climates there often are two maximum discharge'seasons. In tropical d6ltas an annual flood corresponds to the rainy season. Turbid water,, even though highly charged with particulate matter and often colder than the sea water., has a relatively low density and is forced to flow out on the sea surf@ce. The momentum of the river carries the turbid freshwater flow for several miles.b6yond the delta margin--as much as 50-60 miles for spring floods in a large river. The freshwater gradually assimilates the surface sea water as it is propelled along. Thus there is a horizontal salinity gradient at the surface in front of the delta (Figure13). (Such strorig.horizontal salinity graaients,do not exist along the bottom in front of deltas.) The suspended sediment concentration at the surface in front of a delta ranges from 10-100milligrams per liter. This is very turbid compared to sea water where the suspended matter is less than 1 milligram/liter, including plankton. The high concentrations of suspended particles in the surface layer block penetration of sunlight. Even in very shallow depths organisms must be prepared to live on the bottom in absolute darkness. The bottom waters may be relatively free of particles but they are shaded from any light. The sedimentation rates' in the vicinity of distributaries of the Mississippi and Rhone (France) deltas ar-e as high as 1 foot per year and in some areas even more. These rates are normal for large deltas. TheY are probably somewhat unusual for smaller ones,, but a rate only half as great would still pose quite a survival problem for all but the most mobile of benthic invertebrates. On the delta-front platforms the deposition is much slower., on the order of 0.1 foot per year. On the bottomset plain the rates are very slow., perhaps 0.01 foot per year,, or even less. On the one hand the continuous rain of particles from above causes a survival problem., but on the qUxr hand, it brings an unfailing supply of nutrient rich food. Thus the environment can support lar numbers of the particular species that can ge survive conditions of rapid sedimentation. YELckenzie, Garrels, Bricker, and T@ickley (1969) show suspe@ded clays controlling water content on one nutrient element (Fig. 31). Thomas and Simmons (1960) give productivity data in Tables 2 and 3. The surface waters in front of deltas are relatively rich in nutrients that are brought.to the sea in,the freshwater. Their abundance fluctuates with changes in the Amount of freshwater flow. Because of the abundant nutrient h;upply a large-standing crop of plankton can be supportea in these surface waters. The most abundant forms are diatoms and copepods. The numbers of diatoms decrease away -from the front of the Po delta (Italy) from about 32)000 ber liter to about 22.,000 per liter-in a distance of 30 miles. Within the next 100 miles the diatoms decrease in number to about 8oo per literi while the effects of freshwater as measured by the salinity virtuaJ4 disappear. It is probably not only the inorganic nutrients that provide for the high standing crop near the delta.. but organic nutrient substances carried by the freshwater apparently influence the abundance and distribution of Table 2. Phytoplankton, nutrients. and photosynthetic productivity measurements in the kissisippi delta MEAN SURFACE PHYTOPLANKTON PRODUCTION IN VARIOUS Mississyppi DELTA Thomas and Sirmons(1960). AREAS DURING LATER FiELL) IAllPs MEAN AND MEDIAN PHOSPHATE t-ONCENTRATION'S AT 11REE SEASONS AND IN Fidd Trip VARIOUS AREAS or THE DELTA November February May 1957 Area Fafi Months February -1fay 1956 1957 - Mean P04 (jUgm-at0m/L) 1.91 1.20 0.81 HoUrIV production (,ugm C/L/hour) 13.8 7.3 6.5 River Median P04 (,ugm-atom/L) 1.03 1;09 038 Estimated daily production (..g- C/L/day) 146 81 85 Number of determinations 4 17 3 Number of determinations 2 16 1 Mean P04 (pgm-atom/L) 1.17 1.68 1.3o Hourly production (,ugm C/L/liour) 10.2 16.7 20.2 Plume 'Median P04 (,ugm-atom/L) O.S8 1.06 0.92 Estimated daily production (jAgm C/L/day) 108 185 298 Number of determinations 19 32 11 Number of determinations 9 21 9 Mean P04 Cugm-atom/L) 0.32 1.26 Hourly production (ygrn C/L/hour) 10.6 32.6 Gulf Median P04 (,ugm-atom/L) 0.35 0.64 Estimated daily production (jAgrn C/L/day) 112 - 409 Number of determinations 10 - 28 Number of determinations 6 0 25 Mean P.04 (;&gm-atom/L) 1.67 1.30 1.21 Hourly production Cugrn C/L/hour) 0.7 221 Breton Sound Median P04 (jugm-atom/L) 1.66 1.30 1.21 Estim@ted daily production (jugm C/L/day) 7 - 2,895 Nurn Number of determinations 4 2 1 1 ber of determinations 1 0 1 - Hourly production (,.gm C/L/hour) - 4.9 - Mean P04 (,ugm-atom/L) 3.70 3.38 Estimated daily.production (jugm C/L/day) - 54 - Blind Bay Median P04 Cugm-atom/L) 3.70 2.45 Number of determinations 1 4 Number of determinations 1 0 1 2 1 0 MEAN AND'MEDTAN CONCENTRATIONS OF SOLUBLE KfELDAHL NITRoGE.N (0RGM"-IC N PLUS M EAN AND INIEDIAN PHYTOPLANKTON CONCENTRATIONS AT VARIOUS SEASONS AmmoNIA) AT VARIOUS SEASO-,S IN VARIOUS -AREAS OF THE DELTA AND AREAS OF THE DELTA A rea Fall Months February May Fall Manths February May Mean soluble N (jugm-atorn/L) 3.93 5.02 4.78 Mean phytoplankton concentration cells/ml '398 2,915 1,588 River Median soluble N (,Agm-atom/L) 3.93 5.60 4.78 Median phytoplankton concentration cells/ml 111 3,056 1,588 Number of determinations 2 4 2 Number of samples 3 4 2 Mean soluble N (pgm-atom/L) 2.88 3.20 5.30 Mean phytoplankton concentration cells/ml 237 1,989 1,078 Plumc Median soluble N (/Agm-atom/L) 1.14 1.96 6.36 Median phytoplankton concentration cells/ml 132 1,383 606 Number of determinations 14 12 - 4 Number of samples 7 8 10 Mean soluble N (jugm-atom/L) 0A1 - 5.10 Nfepn ighytoplankton concentration cells/ml 662 - 700 572 Gulf Median soluble N (,ugm-atom/L) 0.07 5.86 med n phytoplankton concentration cells/InI 316 Number. of determinations 8 - 9 Nuinber of samples 8 - 26 Mean soluble N (pgm-atom/l.) 2.20 2.28 1.78 '.Nlean phytoplankton concentration cells/ml 1,619 22,097 3,202 Breton Sound Median soluble N (;igm-atom/L) 0.50 2.29 1.78 'Median pbyloplankton concentration cells/ml 765 22,097 3,202 Number of determinations 5 1 2 Number of samples 5 ean soluble N (jugm-atom/L) 1.46 - Mean phytoplankton concentration cells/ml 3,302 4,270 Blind Bay Tzliedian soluble X (jugm-atom/L) 1.46 Median phytoplankton concentration cells/ml 3,795 3,264 Number of deter minations 2 Number of samples 4 3 Table 3. Photosynthetic productivities in, the kissisippi delta 307 Thomas and 3immons(196o). SURFACE: PRODUCTION AND AsSOCIATEID'NIEASUREUEN-Ts DTIRING SEAWARD TRAVE:RSES oN FEB. 21, 1957 Houriv Estimated Secchi station Production Daily Disc Chlarinity Tempera- Phosphate Nwnber Area' Time jugm CILI Production Reading lure *C. (ugm-at-l Hour ;tg?;z CILI L) Day (CM) 963 0735 14.2 158 10 0.12 14.0 0.91 964 0745 16.4 182 10 0.04 14.0 0.66- 965 0805 nA 235 10 0.04 14.2 .1.05 966 K 0815 34.6 384 15 0.14 14.0 1.07 967 K Ow 18.9 209 100 5.69 16.0, 2.31 968 K 0910 17.3 192 100 13.76 15.8 0.85 969 L 1230 25.2 280 76 14.91 14.5 0.90 970 L 1255 .24.8 275 51 13.71 14.5 1.10 971 L 1310 21.6 240 76 12.26 16.0 1.23 972 L 1325 1 22.1 245 61 12 *97 16*2 1,51 973 K 1400 16.2 180 8 0 *14 16.2 1.16 974 j 1415 6.0 67 6 0.04 16.0 0.78 973 1 1445 1.7 11 19 6 0.04 14.0 0.90 SURFACE: PRODUCTION AND ASSOCIATED PARAMETERS DURING.SEAWARD TRAVERSES INNIAY 1957 Houriv Estimated Secchi Daily Tempera- Phosphate Date Time Station Production Disc Chlorintly /fire (jugm-aloml Number A real Ig"? CILI Produclion Reading oc. L) Hour ugm CILI (CM) Day 1957 May 3 1445 989 A 6.5 85 3 0.06 19.4 0.35 0750 984 C 3.6 47 20 2.43 20.1 2.67 0830 985 E 7.3 96 107 8.64 22.2 0.57 0915 086 F 24.0 314 244 14.08 24.5 0.43 0945 987 F 28.9 379 315 15.11 23.9 0.43 Alay 7 0650 1,007 G 16.9 222 10 0.17 19.4 0.69 0700 1,008 G 20.5 268 10 0.58 19.4 1.18 0710 1,009 G 30.6 401 15 1.54 18.9 1.34 0720 1,010 G 74.8 980 8 2.93 20.0 1.34 0730 1,011 H 81.4 1,067 30 6.54 22.2 1.40 0800 1,012 H 97.5 1 1,278 61 5.94 21.1 1 1.56 308 0 SEA WATER CONTRM ------------- 20 0 KAOLIUITC 0, L01VI Tr C Range of Si02,,, 0 concentration for GLA'jC0,V1.rC the bulk of ocean E 10- waters. CL MONTMOkILLONITE A GLAUCONITE KJ@OLINITE A '@O '00 _0 2000 40 60 8000 10000 TIME IN HOURS Fig. 1. Conccntration of dissolved silica as a function of time for suspensions of sili- cate minerals in sea water. Curves are for 1-g (< 62 1z) mineral samples in 200 ml of silica-deficient (SiO, in water was initially 0.03 ppm) and silica-enriched (Si02 -as initially 25 ppm) sea water at room temperature. Size of symbols indicates precision of SiO@, determinations. Dash-dot line shows minimum SiO-_@ concentration of sea water in equilibrium with a hydroxyiated magnesium silicate at the pH's of ctir experiments. .Fig. 31 Q)ntrol of silica content of 'waters by suspended clays (Mackenzie, Garrels, -bricker, Bickley, 1969)_ !1c /0 YAP 241- cfintKCR 50 ?0 7 r A m j ,%.N.-rage mon.thly catch per trip of, industrial fish by trawlers of four I-Ai.ss-*--sjpp` petfood plants during 1959. Species composition by weight of trawl. caught industriad fishes @ro=i January r@ 1959 to April 1960. Fig. 32. Trawl catch off the Kissisippi River (Haskell, 1960). 309 plankton as well. The number of zooplankton (tintinaids, copepods., worms., and larvae of various kinds) is about half the number of diatoms in any water sample. Similar distributions have been observed in front of many deltas, including the Mississippi. Robinson (1957) found suspended clays bene- ficial to filter feeding plankton (Fig.- 33). The fauna that inhabits.the bottom can be divided into a microfauna., including foraminifera and ostrocods,, and a megafauna that includes quite. a variety of relatively large invertebrates such as clams,, gastropods., and crustaceans. Within the active distributaries the bottom supports a unique foraminiferal fauna which is poor in number of species. The exact species vary with the actual salinity and temperature of the water., but they are .types that are transitional between freshwater and ma ine varieties and capable of withstanding large salinity fluctuations. In the pro-delta slope area the fauna is adaptable to the rapid sedimentation rate. It consists of a few (usually three or four) species that have definitely ma ine affinities., and it is characterized by having a very large proportion of living population. This characteristic fauna has been studied in the Mississippi delta area by Lankford (1959). for example. When a delta builds into a'lagoon or bay,, where the salinity is not fully marine., the foraminiferal fauna may not have marine affinities,, but it retains the characteristic that it is composed of a very high proportion of living forms of only three or four species. Beyond the pro-delta slope the species composition becomes more diverse. The tempera- ture, water depth., and other ecological factors control species composition. Other small organisms., such as ostracods,, show similar distributional char- acteristics between distributary, pro-delta slope, and bottomset plain regions. Distributions of the larger invertebrates are influenced by many of the same factors as discussed above. However.. adjacent to the deltaic distribu- taries extreme fluctuations in salinity and'water temperature,, as well as an unstable substrate., produce environments that are extremely hostile to most larger., relatively immobile., invertebrates. The number of species that can populate such environments,, therefore., is small. Within the distributaries,, salinities become quite low during most stages of freshwater flow. This excludes marine pelecypods and similar sessile forms. The high turbulence and turbidity are other factors inimical to the existence of marine species. But the more motile animals--crabs, fish, shrimp, etc.--invade the distribu- taries when high salinity water enters them at periods of low freshwater flow. Should floods follow a period of extended drought, mass mortalities of the larger invertebrates are likely to occur. Adjacent to the distributaries where salinities are less than 10 o/oop the faunas consist almost exclusively of a few pelecypods., a gastropod or two, two or three crustaceans., and a few fish of various sorts. Of these., the pelecypods are the largest and most diverse forms. They consist of four or five species (often including oysters). In the pro-delta slope region pelecypods, gastropods,, and crustaceans become more abundant and diverse. The species become more akin to ma ine forms. The organisms are adapted to life on muddy bottoms and salinities just slightly less than marine. Beyond the pro-delta slope it is the nature of the bottom lithology--whether sand or mud--that is the dominant control of the faunal composition. Sandy bottoms sustain a very diverse group of Tna ine pelecypods (a dozen species), gastropods (6V8 species)., ' and occasionally echinoderms, Relatively few species occur on mud bottoms., but where found they are very abundant. As the water depth increases and siltation decreases farther away from the delta: species diversity increases and the number of known species becomes very large. > K-5 Z. 3 p 5 C+ co n FL 1:@ z 5 t t: 9' 6t "0 t* C+ 0 rz Q.,-, ge, 5 z EO r C, c 0-5 M 31t Da Fig- 32 are data on the fish catch,by trawlers operating in and around the delta system of the Mississippi; it gives some suggestion as to the fish populations. The contrast between the delta and less disturbed surroundings is especially sharp in the work of Lowman and associates on the AAasco River example (Figs 1.9-30)- Note the sharp changes in trace element contents of the sediments and the role of.organisms in controlling many elements. The establishing of frequency distributions which show high , skewed variability of trace elements in biological materials is one of the results of these studies. From the above discussion we see that the stresses imparted to ecologi- cal niches in'the sedimentary delta environment are extreme and of a variety of kinds. Both speciation and species diversity reflect the dominant physical, nature of these environmental stresses and their variations from one place to another. 312 Chapter A-6 HYPERSALDE LAGOONS B. J. Copeland Scott W. Nixon The University of Texas University of North Carolina Port Aransas, Texas 78373 Chapel Hill, North Carolina 27514 =ODUCTION In the arid coastal regions where evaporation exceeds freshwater shallow estuarine waters become hypersaline (salinity above about 40 gm/kg (Ppt)). These "lagoons" are characterized by the marked lack of freshwater input and they are isolated from the sea by long narrow barrier bars - their only connection with the sea is through "passes" in the narrow, ofti@n intermittent, barriers. As illustrated in Fig. 1 and in Fig. 2) the typical hypersaline lagoon tends to evolve parallel to the shore with narrow passes usually near the ends of the water body. While the single most dominating feature of hypersaline systems is that of salinity, other parameters are important in determining which'of the three main types of biological components will develop - grass flats, plankton based systems, or blue-green algal mats. When water depths axe very shallow, perhaps 10 cm. or less, eddy diffusion becomes minimal and a laminar system may develop in which blue-green algal mats dominate and dissolved oxygen levels fluctuate widely between supersaturation during the day and anaerobic conditions at night (soilins 1969). In deeper waters of several meters, where light may still pen- etrate to the bottom on calm. days and salinity is not excessive, extensive under- water meadows of sea grasses may develop and serve as shelter and breeding grounds for fish and various invertebrates. Such grass systems may persist only where the morphology of the lagoon is such that the fetch-of prevailing winds remains relatively small and turbid conditions do not result from wind generated waves churning -up the shallow bottom. When the turbidity of the water becomes too great, plankton systems dominate over the light limited benthic ones and cause concomitant changes in the density and species composition of animal pop- ulations. The concentration of salts in the hypersaline lagoon waters represent a sea to land concentration gradient, with the highest concentration being inland. With no head from river inflow to provide the circulation balance in the lagoon between fresh and sea water, there is a net inflow of sea water to replace the evaporation of water. This results in a net evaporation increase at the inland edge of the lagoon (or, in some cases, as distance away from the seawater source increases). With continued lack of freshwater input, the evaporation-seawater replacement phenomenon results in continued increase in general salinity of the water, such as has been the case in the Texas and Mexican lagoons during pro- longed droughts. On the landward side of hypersaline lagoons are the expansive areas known as pans and flats (see the illustration from Nichols 1966 as reproduced in Fig. 3). These shallow flat areas are important for nutrient circulation and 313 SCALE 0 10 20 MILES ST JOSEPH ISLAND PORTARANSAS Corpus Christ i MUSTANG ISLAND PADRE ISLAND + 27-0- TEXAS Z@ ............... (L R110 GRANDE ownsvill@. + 26'0' 0 LL Matamoros Q) MEXICO TAMAULIPAS 0 0, LA CAPIA San rernando + 25-C CARV, AL -A A, .-a -@C,js Maria FALAD FiC. 1. Diagram illustrating the reogrpphicpl locetion of the LaFuna lf-adres of Texas Pnd Meyico (From Copeland and Jones 1965; Fig. 1). 314 BAFFIN SAY LAOUNA MADRE BAFFIN SAY LAGUNA MADRE West 8"th well am$# South - north April It, 1964 A WF11 14. 0965 45 55 uOy 19 43 55 30 juiv 7 a 45 as ------------- %=@@ @) Auqr 81 4 Aucust 6 so -- 45 as S@p$#mb#r 4 29 is N- Octo-bor 7 Novombor 3 4s . ... .................. ., Ctabor 23 00combor 3 45 ... C-rL 5 as P Nowomber 19\ obru N Fobru fy 4 35 March I 26 35 -May 13, 0966 as r Fig, 2. Surface salinities for Baffin Bay and Laguna Madre, Texas (From Behrens 1966; Fig.2), The Baffin Bay- 'Laguna Madre sampling transect is indicated in Fig.1 by the dotted line. .315 >200 In fersf if J*@i water SALINITY -42 Lagoon water -40 8.11 %0 214 T "HIR 36 Interstitial -12 PHOSPHATE I agoon 6 water Ag DISSOLVE -4 rolo/ free- woter'P9 k.!!!) GROSS PRODUCTION raott &.Pg 4- 9 Y NET PRUUUL;rION + % 0 (IY PANS 49 FLArs-1 1hrA 0, j out . . . . . . . . . . . 0 OEFTH M. Fig- 3 Hori zontal distribution of salinity, phosphate, and community production in the hypersaline lagoon (Estero Tastiota) of Sonora) Mexico. From Nichols (1966). 316 net transport of water. The shallo@ness of the flat areas allows the rapid evaporation of water and generates a pattern of landward circulation. With the ebb and flow of waters due to wind changes and tidal effects, the flats are alternately drained and flooded. According to Nichols (1966), character- istic bioge'och&mical cycling in these areas results in a buildup of nutrient materials, such as phosphorous, in the evaporating pan watersp wh@ch are re- turned to the lagoon during the draining of waters from the flat. Any biotic system that is capable of living in hvpersaline waters must have the adaptiv6.ability to contend with high salinity (osmotic problems). differential ion precipitation, and strange pH, dissolved oxygen and tempera-6ure regimes (Copeland 1967b). The results of this harsh environment are a reduced species diversity,-a modification of biog6ochemical cycles, a modification of the food web and a modification of the general productivity an4 economid value. The contributive energies normally coming from river input with its organic and inorganic foods are almost completely eliminated in the hypersaline lagoon system, except during rare floods. The process of evaporation, however, tends to concentrate the inorganic and organic constituents of the water while decreasing the.relative volume of water. The river input materials are also partially represented by the erratic floodwater contents from the arid drainage area (the infrequent'rains in'arid areas tend to come at irregular intervals and in large a un s,jthus proyiding erratic input to the hypersaline lagoon). EXANFLES Laguna Ybdre, Baffin Bay, of Texas The Laguna Madre and Baffin Bay, Texas (Fig. 1) 'constitute the most exten- sive hypersaline,lagoon system in the United States. Certainly it is the most intensively studied of slich systems,. and from the work of Collier and Hedgpeth (190),'Breuer (1957, 196@), Odum and'Wilson (1962), Hellier (1962), Parker (1959) and Odum, (1-967b), 6, gon@ral*qom: I a the system can be made as in positd di gram of Fig-.4. The high splar ikisoi&@ion (greater than 700 gm.-cal./cm2/day in sil r, personal observation) generates substantial evaporation rates and results in natural stresses of high temperatuie@; and salinities, especially in the shallower waters around the.edj6d'of the lagoon. 'As shown in Figure4 , these areas are domin --d by extensive blue-green algal mats and associated bacteria. As salinities become increasingly higher as in the isolated arms of Baffin Bay (see Fig 4), less soluble sa .ltIs such as.CaC03';oay beciomp s.aturated pa* precipitate over the mat giving rise to oplitic f6rm%tions characteristic of such environments. As evapoTation continues, nutrients and organic materialp are concentrated as well as'salts, and this evappr4tive fertilization may be an integral part of the mechanism by which organisni@ are able to generate the energy necessary to meet the drains of osmotic stress adaptation. The conc6ntration@ of a major nutrient,, phoap@@'@rusl in'the Laguna Madre - Baffin Bay system are compared with those in the parent water of th6 Gulf of M@xilcp in Table 1. As illustrated in Figure 2, there is a significant increase in salinity with increase in distance from the sea-l&gogn connection. Behrens (1966) was able to show a 15 to'40 ppt. differeiice in salinity between the north end (lower) Nueces say jIff.- 317 q q 4 %r'' p- b-AT C.'r.s ch" -It Fk2 AT Roay S 10 @JA p- Rt 4' S 41 - Bay P: R- 7- S Gui f mex ir-o 27* F7.' R- L- L2 S- L q#-6 P%@.tesymt 1%esia Ps Gras% Ar., Ld R-Total Re%piratlios4 cc 14 JMSIMR/Jay Sq.4 Specles Diversity iW Wvm6er -4 Spegitj IA per looo X"j*,vjj.4j$ SO A. 44S C 3 b R 5-33 AS. jaj'pe-cr@w 611@al Mats 2 6' P1aQKte4 lbas.j SystemS CGMS Q.44P Reeft Diplawrleta Mexico S.**-% Pig- 4. Composite diagram of the Texas Laguna Madre and Baffin Bay, showing the distribution of salinity in ppt, photosynthesis, comminity respiration, species diversity, and dominant com- Tminities (From Breuer 1962, 1957; odum. and wilson 1962 and odum, 1967 b). 318 Table 1. Phosphorus concentration in mg-at/m3 for Baffin Bay, Laguna Madre and Gulf of Mexico (From Odum and Wilson 1962-, Table 2). Numbtr HYPERSALINE BAYS, salinity, 50 to 70%o Baffin Bay, July 26, 1957 8 2.7-5.2 Baffin Bay, August 15, 1957 9 3.4-4.2 Upper Laguna',Nladre, July 23,1957 4 1.4-3.2 Upper Laguna Madre, August 1, 1957 8 3.4-4.2 GULF OF MEXICO, salinity, 33 to 36%c Port Aransas jetties, July 15,1957 8 2.0-2.2 Port Aransas jetties, July 23,1957 1 1.8 Whistling buoy, Port Aransas, August 10, 1959 4 0.0-1.27 Table 2. Organisms normally found in Baffin Bay, Texas (with the exception of nannoplankton) (From Breuer 1957). DIATOMS FISIT Navicula sp. X77177,- prora paludosA Arridae DIN01FLAGELLATES Galeichthys felis Ceratium hiriandinella Cyprinodontida-e COELENTERATA Cyprinodon variegatus Phortis sp. AntherinLdae CTENOPHORA Menidia beryllina peninsulae Beroe ovata Mugilidae MOLLD7S-CA- nEa ceplialus Mulinia lateralis Sparidae COPEPCDA Lagodon rhomboides Acartia tonsa Sciaenidae CIR.RIPIDT-A Cynoscion nebulosius Balanus eburneus Sciaenops ocellatus AMR1 ODA R-icropogon' undulatus Gamnarus mucronatus Pogonias cromis DECAFUD-A Doth.iTa-e Penaeus aztecus Paralichthys lethostigma Carl-'M-ec-Mes -sapidus Table 3. Fishes normally caught in hypersaline areas in the Texas Laguna Madre ahd Baffin Bay (From Gunter 1967bl Table 1)o 1'gu- Mad- Baflin w1p, "w" qV, i'." @"d " to 150-fil) I'I't Flopswurus Galrichlh)-s felis Anchoa hepsews Cyprinodon Variegalus Fundulus similis Menidia beryllina C)'Prinodon variegalus Magil cephalus Menidia beryllina Lagodan rhomboides Nugil Cephalus Cynoscion nebulosus Lagodon rhomboides Sciaenops ocellatus Cynoscion nebulosus Nlicropogon undulatus Pogonias cromis Pogonias crornis Micropogon undulatus Paralichthys Irthostignia 30 of the Texas Laguna Madre and the west end (higher) of Baffin Bay (a distance of 40 miles)., except during the infrequent time of heavy rainfall (may-June 1965 and may 1966). Other examples of salinity increase toward the inner areas of hypersaline lagoons include Breuer (1962) for the lower Texas Laguna Madre, Simons (1957) and Collier and Hedgpeth-(1950) for the upper Texas Laguna Madre, Nichols (1966) for a Sonoran lagoon, and Hildebrand (1958) and Copeland and Jones (1965) for the Mexican Laguna Madre. Organisms Due to the need for osmotic stress adaptation, the,diversity of organisim in hypersaline waters is low (Copeland 1967b). The magnitude of the stress in- volved is a function of the energy drains of adaptive work required for the species to remain as a part of the pax-t@culax system (Odum, 1967b). Such energy demands are complicated and extended by fluctuations in the stress itself as pointed out by Parker (1959) in reference to the invertebrate animals of hyper- saline areas: Both in hypersaline and vei*y low@-salinity regions,, the variability and adversity of the environment determine the species composition and comparative abundance of each species. In extremely variable hypersaline areas, the number of species is very low, and the num- ber of living individuals is small also. In stable hypersaline areas (and stable, very low-salinity waters), the number of species is still small, but the number of living individuals is extremely large. As the salinity decreases or increases to normal values (along with relative stability), the number of species increases and the number of individuals per species decreases. Work by Breuer (1957) and by Gunter (1967b) a ng many others has affirmed the validity of this principle with respect to a variety of organisms living in the Laguna Miadre-Baffin Bay complex, especially with respect to the fish of these environments. Their data are reproduced in Tables 2 and 3 respectively. Fish in the plankton based system of Baffin Bay tend to be largely planktivores, since the low productivity and the energy drains of osmotic stress my prohibit the development of an extensive level of secondary carnivorous consu rs. This situation has been carried to the extreme in areas of brine pollution (see chapter on Brine Pollution Systems) where the fish population my consist entirely of planktivores. An idealized and simplified food web for Baffin Bay is shown in Fig. 5. It is unfortunate that little, if anything, is yet known of the bacteria and fungi of these systems, though there exist many species of decomposers that are capable of activity in even more severely stressed environments. Ade- quate substrates should be present in abundance in the form of vast acres of dead sea grass during the winter in the Laguna Madre, in the form of complex bacterial-blue-green algal mats across the extensive mud flats around the Laguna Madre and in the upper arms of Baffin Bay, and on the turbid particles of sedi- ment suspended in the high levels of dissolved organicr;,found by Wilson (1963) in the Baffin Bay area (see Fig. 6). It is interesting to note that Wilson was able to show.some of the highest levels of.dissolved organics associated with salinity stress in these systems and in the commercial salina systems of Puerto Rico. From his data, and thcse of others, Odum. (1967b)Zs Table -to show an inverse hyperbolic relationship between species diversity and dissolved organic storage 320 Suspended Organic Bottom 0 g=anc- Material Material _j Balanua.* CvPrinod2_n-4- C+ ..o L., i - - Muizil 2/2 -4- I Mulinia 10 --- Microvogon 3/4-k Penaeus F Callinectes-t= _Gvn scion 2/3 Paralichthys 1/2-+ Gall ichthys -m.-Micropogon 2/44-- Scianops l/2'*--*_'aammaru* LaSod on 1/2-4 6-r 6*.Pogonias %.-Gale ichLtys 2/3 algae 2/2 Men idia 2/2 L*_Micropogon 4/4 Cynoscian 4 3/3 Pognias 1/2 L_@_ScianoRs 4 2/2 *O'Menidia 1/2 Paralichthy.9 L_ 2/2 1/2 -4 Acartia -diatom v Galeichthys 1/34 Micropogon 1/41 Cynoscion 113 Primary Tertiarv Consil rs Secondary Consumers Consumers_[Producers Fig. 5. Idealized food web for Baffin Bay, based on data from Breuer 1962 9 (From Shapiro 168; Fig 321 LAGONA MADRE 154 I z MCC 41.5 ZJ SAY 2T.9 2's 142 2.4 2 OF 00 MEXICO 213 21,2k BOO 19.6 21.9 FJN SAY Fig. 6 Total carbon in hypersaline waters of Baffin Bay and the Laguna Madre, Texas. Carbon in mg/I (From Wilson 1963; Pigs. 3 and 4). 322 in the system. The possible significance of such large external storages has,been discussed more fully in the chapter on Salina Systems and by Odum (1967b). In the Laguna Madre itself, where salinities are lower than in Baffin Bay and the water less turbid, the vast underwater grass beds of Diplanthera andless significantly, Thallassia permit the development of more complex food webs based on the higher primary productivity of the benthic systems. The distribution, growth and reproduction of bentaic algae and spermatopbytes in the Laguna Madre have been described by Conover (1964). As shown in Fig. 4, the prevailing winds of the "Texas" system are out of the southeast (U.S. Weather Bureau Records) so that the longest fetch is achieved across Baffin Bay and Corpus Christi Bay. -These strong winds help to create very turbid.water in the Baffin Bay system which shades out the benthic grass comminities characteristic of the Laguna Madre and supports a low diversity system of plankton. In these systems production and biomass tend to be low compared with the grass systems, and respiration may exceed photosynthesis. Metabolic 2@tterns Using the diurnal curve methods developed in Texas waters by Odum (1956) and Odum and Hoskin (1958)., various investigators have obtained several years' data on the daily and seasonal changes in photosynthesis and respiration in the Laguna Madre - Baffin Bay complex, as well as biomaw. data for the important animal populations. Diurnal curves of oxygen in the Laguna Madre and Baffin Bay are given in Fig. 7. The depressed values for the Baffin Bay axe partly the result of the decreasing solubility of oxygen in waters of higher salinity (Copeland 1967b), but the actual productivity of the system is indicated by the lower rate-of-change graphs where the values have been corrected for diffusion. The stippled area above the dashed zero line indicates net production occurring, while similar area below the line is a measure of system respiration. In sys- tems where the area below the line is greater, as in*Baffin Bay, respiration is exceeding.photosynthesis and P/R ratios drop below 1.0. In the Laguna Madre, there is a greater area beneath the curve above the zero line, and there is a net production over 24 hours. Based on many such curves taken in all seasons and over a number of years, Odum and Wilson (1962) prepared the seasonal metabolic pattern curves shown in Figs. 8.and 9, as well as the values shown in Fig. 4 (Odum. 1967b) Data in Fig. 8 indicate that the Baffin Bay system remains heter- otrophic at almost all times measured and must therefore depend on some organic imports, perhaps from the less stressed Laguna Madre (Fig. 9) which is relatively well balanced in terms of -production and consumption over a four-year period. Respiration follows productivity and in both systems they are highest with the strong seasonal pulse of solar input. As salinity stress increases, it appears that the energy necessary to cope with it also becomes increasingly available. It would be interesting to speculate if the effects of increasing salinities in systems are greater at higher latitudes (examples: brine pollution and brine residue from the freezing of sea water) where the solar energy input of the system is not so large as in naturally occurring subtropical hypersaline systems. Role of miaation of fish and crustacean Contributing to the balanced coupling of production and consumption in the Laguna Yladre system are the migrating populations of breeding fish and associated invertebrate animals that enter the system because of the protection and food z too Q fn 0 ro 0 0 0 0 bD bo fo (A CA m 0-1 op of 0 p 19 R. P, co 0 0 r P, Fj 0 Kr 0 \51 z flo OD a ib .4 (A 0 Fl- Fa cl -4 OD uo F4 c z > > r I( rp z z N 0 C+ ol cze 324 BAFFIN BAY, TEXAS so 70 so. so 1,57 logo 1060 Fig. 8. Comminity metabolism data from Baffin Bay., Texas during 1-957 through 1960 (From Odum, and Wilson 1962; Fig. 24). AI X.0 L 60 Fig. 9. Community metabolism data from Fig-10. Total biomass of animals from the Laguna M3dre during 1957 a drop.;-net quadrant compared through ig6o (From Oaum. and with gross primary production Wilson 196R; Fig. 7). in the Laguna Madre (From "M I 16A.$ .. ..................... 9 Hemer 1962; Fig. 13). 325 offered by the grass beds. Work by Hellier (1962) has shown a propensity for the animals to, in effect,arrive in the area just as the food becomes avail- able. When the total animal biomass shown by Hellier in Fig. 10 is broken down into the individual component species, the same general trend remains (He,llier 1962). Laguna Tamaulipas, Mexico In northeastern Mexico south of the Texas Laguna Madre (Fig. 1) there is a similar long lagoon running parallel with the coast as part of the same geo- logical continuum of offshore barrier islands and shallow water systems. Here, in the Nbxican Laguna Madre (Laguna Tamaulipas), conditions were very similar to those of the Laguna Madre of Texas until 1961, when the narrow passes that served to connect the Laguna Tamaulipas with the Gulf of Mexico were filled in by hurricane generated waves and currents. Once these sources of sea water in- put were closed the continuing effects of evaporation became more pronounced and salinities rose to produce the only remaining coastal bay within or adjacent to the United States that resembles the primeval conditions which existed prior to the rise of extensive industrialization and civilization along the Texas coast. During the past few years, due to natural changes in the morphology of the lagoon and barrier island, the Laguna Tamaulipas has ranged in salinity from almost fresh to sodium chloride saturation (about 290 ppt) (Copeland and Jones 1965; Copeland 1967b,personal observation). This process of concentration pro- duced new and far greater stresses resulting from differential ion precipitations and greatly reduced oxygen solubility, as well as pH fluctuations and extreme osmotic energy drains. Such a system also comes to resemble those of commercial salina systems where sea water is evaporated to produce salt, but with the impor- tant exception that the water is not removed from the salts as they precipitate. Studies of the changes in gross productivity, community respiration, and species diversity of fish were reported by Copeland and Jones (1965) and Copeland (1967b) as a function of increasing salinity over the five year period 1961-1965. Their results, as shown in Fig.11 , show the expected sharp decrease in fish diversity 'with increasing salt stress. Once again, their data make the point of in- creasing respiration with stress while gross productivity decreases. Unlike the salina, this system failed to develop great numbers of red halophilic bacteria at the highest salt levels, and as a consequence respiration appeared to drop at the final stages of succession. Lagoons of lower California Along the west coast of the United States undisturbed hypersaline lagoons once existed in parts of southern California. Further south, along the shore of the Gulf of California in Yexico, Nichols (1966) has studied the phosphate levels and metabolism of still unpolluted Sonoran lagoons. His results again point out the importance of wind in generating turbulence and turbidity which decrease pro- duction in shallow water systems. Phosphorus and salinity gradients are shown in Fig. 3 emphasizing a positive correlation that is similar to that in the Laguna Madre-Baffin Bay area (see Fig- 3 ) and results from progressive evaporation and, to some extent, from land inputs of phosphorus during brief erratic flooding. Fig. 3 also indicates that net production was lowest in the turbid grass (Zoster system in the center of the lagoon and highest in the deeper, less turbid plankton system off the lagoon mouth.,,The surrounding pans and flats were dominated by 326 30 300- Laguna Tamaulipas mexic@).'-X-.. 2501 2--20 L/) FISH SPECIES LL LL 200- 0 / Ul) t LLJ 150- )r kT 9- SALINITY Lou it -10 < 100- 50 19 61 1962 19E 1964 0 Fig. 11, Salinity@ fish species, gross photosynthesis and comminity respiration for the Mexican Laguna Madre, 1961-1965 (From Copeland and Jones 1965; Copeland 196716). MAP of PUNTA PIEDRAS and BOCA JESUS MARIA co Jesus -24"30* Punto P@ .e ros Punto A14odon ;@g 0 5 T'AMAULIPA GMEXICO 97',30' Areas f rorn which collections were obtained in the lower Laguna Madre of Nlexico near Boc a JesusMaria. 80C (liumm and Hildebrand, 1962) 327 blue-green algal mats having intermediate levels of net production. Except for the interstitial water of the pans and flats, however, salinities in this system were considerably lover than those in the Laguna Madre or Laguna Tamaulipas. Hypersaline pool - St. Joseph Island, Texas The high spring sea levels occurring along the Gulf Coast of Texas in April fill shallow depressions in the barrier islands with sea water. Through the following months, this trapped water evaporates and'becomes increasingly hypersaline. By,July, carbonate has begun to precipitate and the system is dominated by red and pink bacteria that my ultimately come to constitute a heterotrophic system based on energy fixed and stored by earlier, less stressed systems. Such ponds would provide an excellent system for the study of changes in species diversity and metabolism in a successional sequence that moves from low stress autotrophic to high stress heterotrophic. Copeland and Jones (1965) have obtained measurements of the oxygen and carbon dioxide metabolism in a hypersaline pool on St. Joseph Island in mid July, befcdie the system has become completely dominated by pink bacteria. Their diurnal oxygen curve is shown in Fig. 12 and indicates a very wide range from anaerobic at night to over 250% saturation during the peak daylight hours. The ratio of gross photosynthesis to total respiration was 0.83 when computed from oxygen data and 2.27 when computed from carbon dioxide data. The R.Q. was 0.3. Such unusual metabolic behavior, perhaps related to the extensive bacterial components, my imply interesting ecological principles of stress adaptation in these isolated ephemeral systems. DISTURBANCES With biological communities already stressed in hypersaline systems, dis- turbances in the system my tend to cause the elimination of more species than similar disturbances in less stressed environments where energy-reserves my be sufficient for adaptive work. With organisms living at the limit of their adaptive ability, they could be eliminated from the system with only small additional energy drains. Also, if some material that was toxic to even a single species was introduced into the hypersaline stressed system, a whole food chain could be elimin d because of the inherent simplicity of the comminity. Impoundment When the Yexican Laguna Yadre was impounded due to the natural closing of its pass to the Gulf of Mexico in 1961, evaporation and sedimentation proceeded to lower the productivity (Copeland and Jones 1965). After about three years of evaporation without replenishing rainfall, the salinity in the system had reached the level found in salinas and the ecology of the system was similar. A diurnal oxygen curve (Fig-.-1-37-,as reported by Copeland and Jones (1965) for a station near CarvaJal (See Fig. I for orientation), indicated that the diurnal oxygen flux was very low. The magnitude of oxygen concentration was also very low due'to the increased salt concentration (Copeland 1967b) and fell below sat- uration values even during the daylight hours. The lower saturation indicated some oxygen derand and community stress. Price (1968) studied the effects of impounding a 35,000 acre madflat on the west side of the Texas Laguna Yadre. The spoil from the construction of 328 pm:; 5- 02 MG/L :j:::.- 0 .......... ... ........ Z 02 2 0 0 D . ... ........ .......... % .. ........ SAT 0 ......... ................ . IST. JOSEPH ISLANO PONDI 14-15 JULY 1963 74 %o SALINiTY + 2.0 ......... .. .. ........... ............ Q2 1.0 .. ....... ... CHANGE ... ......... ..... ............ . .. MG/L/HR 'd .......... 1.0 ....... ...... ............... .............. .......... .......... ....... ..... 06 1'2 Is 24 Fig-12 Diurnal oxygen curve for the St. Joseph Island PondA Texas for 3-4-15 July 3-963 (From Copeland and Jones 1965; Fig. 7)- 329 6- IP. . . . . . . . . . . . . . . . . . . . . 5 - 02 4 MG1L 3 .......... 2 6 ........ .. TOC 0 2 4 0 T 2 10 0- CC ........... % 9 0 22 S AT 0 %SAT 8 ............- 2 0 70- CARVAJAL, MEXICO STATION I 24-25 MARCH 19631:: 02 CHANGE .... .... .. .... 0.0-1 70 MG/L /HR ....... ... ... .50 - T6 1'2 i's 24 Fig. 13. Diurnal oxygen curve for station 1 at Carvajal In the Mexican laguna Madre (From Copeland and Jones 1965; Fig. 5). 330 the intracoastal canal through the Laguna Madre was placed along the Laguna side of the extensive mudflat area. With the prevention of normal flushing of waters across the madflat during wind shifts and high tides by the spoil dyke, the water over the mudflat (over a portion of the madflat during extrem- ely high spring tides) evaporated and the'strong prevailing winds blew salt- laden sand westward over several thousand acres of pasture land and killed the grass. The extensive blue-green algal mat that had spread over the entire madflat during the normal flushing and draining activities was destroyed, leaving exposed soil overlaid with salt crystals. Organic Pollution Sewage disposal at La Capia in the Mexican Laguna Madre (Copeland and Jones 1965), resulted in lowering the oxygen concentration to zero. The organic material in the presence of high salt concentrations settled to the bottom and smothered the dominant algal bottom community. This lowered the productivity and the species diversity of the system to almost zero. Dredging Spoil The deposition of dredging spoil in the upper Laguna Madre of Texas covered the grass beds and blue-green algal mats on the shallow flats, thereby elird ting the dominant bottom producers. With the shallowness of the water, extensive plankton systems could not develop because of the lack of circulation and flushing (odum and wilson 1962). The net result was a decrease in productivity of the covered area and elimination of fish species. Navigation Channel Hypersaline conditions over 100 p.p.t. existed naturally in the Texas Laguna Madre until 1949 when the completion of an intracoastal waterway modified the morphological characteristics that once existed. Accordingto Collier and Hedgpeth (1950) and Behrens (1966), the establishment of extreme hypersaline conditions that were once possible has been prevented by the availability of larger volumes of water from Corpus Christi Bay on the north and the Gulf of Mexico'on the south via the intracoastal canal. This is possible because the sills that existed at both ends of the Laguna Madre hAve been cut by the canal. A similar waterway is projected for the Mexican Laguna. 331 Chapter A-7 MARINE BIBE-GREEN ALGAL MATS Larry Birke University of North Carolina Chapel Hill$ North Carolina INTRODUCTION Very shallow coastal waters are often subject to extreme environmental stress. This stress may result from the high diurnal ranges of natural.pro- perties such as oxygen and temperature that.are influenced by daily variations in the-sun's insolation or by pollutants from the adjacent land. In these areas the varying or extreme conditions favor organisms highly adapted to this stress which are able to form viable ecological systems. Blue-green algae are especially well suited to this type of environment (Vinyard 1966) and gr ow abundantly under these conditions where ordinary floras and faunas cannot survive * Associated with the blue-green algae, is also a collection of plants and animals unique to this system,, but the nature of the physical environment causes species diversity to remain normally quite low (Fig. 1). EXAMPLE - MATS IN SHALLOWS OF SOUTH TEXAS An example of a blue-green algal mat system is located on sandy shallows around Baffin and Alazan Bays and the Laguna Madre on the southern Gulf Coast of Texas (Fig. 2). The high evaporation, low precipitation and little fresh water input of this region (Di.@ner,1964) frequently cause these bays to become hypersaline. 1- Adjacent to these shallow salty bays$ vast areas of land are ocas- sionally flooded, and as the water recedes some of it is trapped on the surrounding sand flats. In this thin layer of water the salinity varies from oligohaline to extremely bypersaline conditions and wide diurnal ranges of temperature., oxygen., redox and pH are present (Odum,, Siler et al 1963). Very few organisms are capable of adapting to this harsh environment., but the blue-green alga,, Lyngbya confervoides.'finds conditions favorable. In some areas this alga forms dense mats and often constitutes 80% of the living community (Sorenson and Conover 1962). Other blue-green algal genera, Oscillatoria, Microcoleus, Schizothrix., Phormidium and Anacxstis are also present but not usually as abundant (Armstrong and Odum 1964; odum 1967b). Tn addition,, unicellular green algae 'flagellates, diatoms, pink and purple bacteria are occasionally found (Sorenson and Conover 1962; Odum, Cuzon du Rest et al 1963). High concentrations of the bacteria Desulfovibrio and Beggiat have also been observed (Armstrong and odum, 1964). 1. io- _7 7-rj Corr*Ixid occasionally present water bug r 50 rrim 10 rnml .-17 L rx 7 . ... ... ",44 Lv,?ghya confervoidos oonforvo,'d-s surf oce-stained zor* active photosynthelic algal micrits zone IWIMij Fig. 1. Represeritative blue-Eween algal mat and sOMe associated biota. 333 I 'o 1 20 CORPUS CHR 0Z BIRD ISLANDS AREAS IN LAGOON EXPOSED DURING PERIODS OF LOW WATER SALTILLO FLATS % GULF OF MEXICO GREEN ISLAND 9 PHYSIOGRAPHY LAGUNA MADRE.TEXAS RIO GRANDE DELTAIC PLAIN. 5RAZOS sA%TiAGO PASS 56- @0' Fig. 2. Map showing the shallow flats around the Laguna Madre, Baffin and Alazan Bays in South Texas. (Modified from Rusnak, 1960; Fig. 2) 334 The animal kingdom is limitedly represented by ciliates, nematodes crustaceans., corixid water bugs,, and an assemblage of worms (soilins 19691. In the mud beneath the mat the small clams,, Mulinia lateralis and Anomalo- cardig clMiemeris,, are occasionally present (Dalrymple 1965); and in the waters above the mat 9@Trinodon is frequently active in salinities as high as 1200/oo (Odum,1967b). Davis (1966) describes waterbug reproduction in 43% salinity in saline waters of Jamaica. DISTRIBUTION Naturally occurring blue-green algal mats are found typically associated with warm water. Shallow coastal areas around the Gulf of Mexico often contain blue-green algal mats (Sorenson and Conover 1962) and the frequency of occurrence becomes greatest in the harsh, dry environment of South Texas. Along the East Coast of the United States as far north as New Jersey., mats can occasionally be found (Pomeroy 1959; B. J. Copeland, personal communication 1969). California, Hawaii, and Puerto Rico also have naturally occurring mat systems (aee Chap. E-13). In many other areas pollution may result in the production of blue- green algal mats. Chief among the stresses that result in mat formation is brine pollution from oil wells and salt producing industries. The Leslie Salt Co. of San Francisco, California, and the Ponce Salt Works in Puerto Rico have developed mat systems (See Chap. E-13 and E-14). SYSTEM CHARACTERISTICS Environmental Conditions Blue-green algal mats are found in tidal basins., small depressions near the shore and broad lagoons which contain from 1 to 50 cm. of water (Sorenson and Conover 1962). The development of most mats occur,, however., in water less than 10 cm. (Odum. 1967b). It has already been noted that most mats develop in warm waters. Algal cells can withstand annual.temperatures from near freezing to 700C (Sorenson and Conover 1962) but mats disintegrate in the winter with lowered temperatures (Pomeroy 1959; Odum,, Sileret aL,1963). Alternate drying and wetting of the mats cause shrinkage and sloughing from the mud surface. When dried, patches of surface crust are often lost to high winds but this dehydration does not usually cause permanent injury. The addition of water to dried algal mat restores vigorous photosynthetic activity within a few hours (Sollin; 1969). Wide ranges of salinity are associated with blue-green algal mats (1% to > 20% salt) but salt concentration apparently has little or no effect on the mat except at very low salinities (Sorenson and Conover,1962). 335 Ginsburg et al (1954) further discusses the factors that influence mat growth and lists them as illumination,, moistureo sediment (grain size), substrate (nutrients), and associated organic growth factors. Little work has been doneo however, to determine the relative effect of each parameter. Community Structure Living mats consist of a laminar arrangement of living plants and animals. Each layer differs in color and composition. While mats from different geographic areas may be composed of different species they all exhibit a typical zonation of a darkly stained surface, lustrous blue-green center.. yellow deep layers and a black bottom area (See Fig. 1). A typical mat is'composed of th ree major zones (Sollins 1969). The first is a felt-like photosynthetic zone consisting of closely packed filaments up to one centimeter thick. The second region is less consoli- dated and nutrition is largely heterotrophic. The third layer is highly anaerobic containing H2S and reduced organic matter. This last layer may extend several feet downward where it gradually blends with tb)a sandy soil. Sorensen and Conover (1962) further divide the photosynthetic zone into three additional zones (Fig. 3). The firsto or topo zone (A) is dark brown to black and acts primarily as a light and temperature shield. This color is due to the staining of Lyngbya sheaths. Staining produces apapery crust 1-20 mm deep. Originally it was thought that staining was due to a ferric colloidal complex (Correns;L889) but later investigations (KYlin,1937) suggest that the staining'is due to a photo-chemical process involving the pigment "scytonemine.' The staining apparently only takes place in direct sunlight and is very effective in reducing incident light (up to 95% lost within the first 0.5 - 1.0 mm). Very little photosynthetic activitytakes place in the first, stained zone. The second zone (B) of the mat produces some additive growth but only in the third zone (C) does photosynthesis reach a peak (See Fig- 3)- Below Zone C the bacteria increase in number and light intensities above the compensation point are rare. The layered structure of the mat acts similar to other aquatic ecosystems., like the Black Sea., in having sharply defined oxidized epilimetic and reduced bypolimnetic zones; but the extreme gradations are made over a much shorter distance (Armstrong and odum. 1964). Characteristics of the various zones as described by Sorensen and Conover (1962). are given in Table 1. Chemical Environment Evaporation of shallow water over blue-green mats may concentrate organic matter up to 100 mg/l (wilson,1963). The surface mat., composed of mucilaginous sheaths and intertwining filaments., trap or fix much of this material. Alsop co-precipitation with inorganic salts build up*high amounts of organic matter in the mat. The result is a distinctive grain type termed algal micrite. The Baffin Bay micrite is composed essentially of 336 GROWTH IN GRA148 DRY W E 1 0 H T PE It W E E K OF AN j AL4 A L ME A T 3 A M P L E W 1 7 M 0IF E G RAM INITIAL WEI 0 N 7 100% a 0-2 a. to. 6 0.4 1 a 1.2 1- I ZONE A 5 %. O'Pth OF algal ZONE 0 Liglif J Oi 3.51 -23- mat in iNilliff,41411 ZONE C ponotration in % of 1.7-A -22.4- a U, f a C 0 0* i I I M ini n a f i .." 22.4 a- 0"6%6 -12:1, algal -of ZONE a 0 % To., ",a ZONE 9 to. 2'. 5. 1. 409,642 a a ft t i 9 r a do C OR. %S\+ 4 a a d 1 -7 Fig. 3. Hypothesis of growth of Lyngbya confervoides for each zone within the mat profile. The growth curve also represents the general growth trend for the mat community since all mat organisms were contributing to the increase measured (Sorensen and Conover, 1962). CIM Cis., C 14.0 C 12:0 18:0 C 1&.2 IF C 18:1 CM0 C 14:0 C MA C1111.1 C tm 2 Veto C.,O emo 3 Tiffie (win) Gas chromatogram of methyl esters of fatty acids from algal mat: 1, the living mat; 2, first mud layer; 3, second mud layer. Fig. 4. Characteristics of blue green mats. The second number indicates the number of double bonds in the fatty acid (Parker and Leo, 1965). Ron C@ 4-14- .in @c C @---O 337 Table 1. Comparison of characteristics from natural blue-green Mato and those grown in the laboratory in microcosms (Sorensen and Conover, 1962). Characteristics of environment from which experimental material was obtained for experiments zone- A a C D E A ?,6,& N.-raber April April @n 1, 24-30 20-28 1_8 1-8 Temperature in *C 19-21 23-28 18-23 24-:26 24-26 Salinity as per cent salt 8.0 4.3 4.1 9.6 9.6 Per cent of surface illumination 100 5 3.5 1.7 0 TotSl* illumination g cal per cm 2 per hr 95 80 65 110 100 Per cent.6ee 02 in air 100 <90 -@50 <10 <1 Color of zone Dark Dusky Lustrous Yellowi@h. Pule bro w n blue-grn blue-grn blue-grn yellow oink pink at below top Depth in mm 04.5 0.2-2 1-4 3-8 4-42 lllurninatli@n gi-it for I hour be""" 1200 ..d 1300 h,,.,, on n d.y d-i.g the ..pr,iror.t.. Th- d.L. lep-I'M ihe high,,t illunli..1i.n per hour he.r. f,ratett light penetrati-i for rach ptriod. Experimental conditions during growth rneasurenicrit@ in laboratory Zone A B C D E Dow April March Novernber April April 13721 .14-30 20-29 9-14 1-8 Temperature in *,C 19-21, 23-28 18-23 24-26 24-26 Silinity as per cent @alt 2.6 for all gravimetric experiments 1.6 for all morphometric experiments Per ce';nt 'of !urface illumination 100 5 3.5 0 0 Total illum ination g cil -Per cm2 per hr 95 go 65 110 100 Per cent free 0.. 21.0 <'21.0 <10 0.05 <0.01 Per cent free Nz .:78.0 >78.0 >85 99* 99* Color of zone Dark Dusky Lustrous Yellowish Pale brown blue-grn blue-grn blue-grn Yellow pink at pink at bottom top 111o Argon. Table 2. Properties of organic matter in sediments from blue-green algal mats (Parker and Leo\ 1965Y. Organic L6cation carbon Cid C@. C@ C, M (0)* (1) (0) (1) Harbor Island algal mat Living mat 1, 32 3100 560 130 1200 Ist'mud layer 1.1 1200 .330 180 330 2nd mud layer 0.84 200 23 97 n.d. BaBin Bay core 6-10 cm 2.0 1.49 53 53 89 17-4.1 0.85 192 35 35 50 60-64 1.1 15465g 10 Numbers in Parentheses indicate the number of double bonds, t The living mat contained 296 Opm CL8(2) and 31 PPM Cis(3). Concentration of the major ratty acids-in recent sediments expressed as parts of fatty acid per million parts of organic carbon of each sediment. n.d., not detected. 338 microcrystalline aragonite intermeshed with mucilaginous organic material and is believed to be directly precipitated from super saturated sea water within the lower mat which may.be induced Iby bacterial action (Dalrymple 1965). The intermittent flooding and drying of the algal flats result in the alternation of sediment and old mat layers beneath the now active mat. Sollins (19P) found 270-64o g/m2 of organic matter in the top layers and 970-1350 g/m! for the entire core. The living mat may contain as much as 34 organic carbon (Parker and Leo, 1965)- Blue-green algal mats may be an important ecosystem in the formation of petroleum. The anaerobic lower mat restricts consumers and favors the deposition of organic matter suitable for oil petrogenesis. A few investi- gators have studied the types and changes in organic deposition in relation to petroleum formation. All recents sediments and the algal mat itself are rich in fatty acids (Parker and Leo,1965) (Table 2). With increased depth there is a systematic change,in the ratio of saturated to unsaturated acids (Fig. 4). The result is a definite gradient through the mat with the early disappearance of highly unsaturated acids. Diurnal variations in pH are also large as the result of photosynthesis acting directly on the carbonate fractions. Alkalinity measurement's in the water over blue-green mats varied from 2.1 - 2.6 milliequivalents per liter (Odumv Siler et al 1963). The mat contains a sharp gradient from surface oxidized to lower reduced layers (Fig. 5). The potential between the top and bottom is often as great as 0-5 v- (Armstrong and Odum 1964). This redox gradient is produced by separation of oxygen that rises and reduced organics that remain below (Odum 1967b). There is a diurnal pulse in the voltage (fig. 6). Sollins. (1969)'has shown that the daily changes in redox 'Potential directly can'be relatedto the storing and use of oxygen with a model which was the basis of computer simulation (Fig- T). The changing oxidation conditions of the mat influence the chemical states of various elements. Sulfur exhibits a gradient of oxidized and reduced forms through the mat with there being high concentrations of H2S and FeS at depth (Odum,, Cuzon Du Rest et al, 1963; Dalrymple 1965). The voltage difference from top to bottom may also be imDortant in the trans- port of nutrients (Armstrong and odum,1964; Odum 19676). Phosphate and Nitrate move upward in the gradient and accumulate .on or near Ithe surface and the violtage difference may also be used to organize the mat. Blue-green algae may be moving into position according to charge. Metabolism Large amounts of carbon ar'e fixed by the mat system. Measurements of oxygen and pH can be used to calculate metabolism (Figs.8 and 9). Sorensen and Conover (1962) have recorded values as high as 10% dry wgt./day growth in the photosynthetic zone. In most mats., ho4ever.,'the,P/R ratio probably 339 )t Fig. 5. The blue-green algal mat solar cell. The potentialacross the electrodes is often as.great Ias 0.5 v. pt (platinum electrodes); A (algal mat and buried (-) electrode); B (water layer,and electrode); and C (incident light) (Odum, 1963). 340 Photoelectric Ecosystem. . ............... .... ........ ...... ...... ot. 7: P!. 0.5. .............. ....... .. . ........ ..... ............... .. .. . ... ....... .. . ..... . ...... .......... . ..... ........ ... .................. ..... . .......... . .. ................ ... ..... .. ........ ........ . ...... . ... 00 .... ......... .. .. ..... .... . .... .. ON . ........ P6. 8.0 we r; &4m.. 5.0 - ...... ..... :'Rd t6.:: . ....... ............... ....... CL current E .050 .......................... 0 ....... ... .......... ....... ....... ..... .. ........... ......... . J 0.0 . ....... 00- . ..... ............. .. .... .... ............ ............ . . . ........ ....... E ON ...... .................................... .050 ........... 4.......... ........... .. ........ ...................... PI-Pt voltage ......................... ... ... .......... .......... ..............:.................................. ........................ .......... ..................I......... ...... ... ..... .. .......... ................ .................... ........... ...... .......... .100 ............... ..... ......... ............... > ............. ..... .......... .............. ..........4....... .... .............. ...... .... ..... ... ... M ......... .. ............ ..... ..... ........................... ............. .4 0.0 ............... ............... .......... ........ .... + ....... ... ......... ............... ....... . .... ........ ....... ... ............ .... . ..... .................. ..... ............ ..........- Top of mot ........... ........ ... ............-........... P . . ... .. ............ ....................... .......... ..................I................. .. . ... .... ........... ........ ............. . ........... ... --- 0 0.5 . ......... > .............. PoW@r ...... . .. ......... --- ..... ...... .. ....... Bottom of mot . ......... i-col. .......... .. .. . ....... ... ........ .... ........... ON 0 F r '4L 0.0 00 12 24 00 12 24 HOURS HOURS Diurnal recorid of variables in the blue-green mat ecosystem with a 12-hour day and a 12-hour' night. (a) -f7he pff in the water 'above the mat and the rate of carbon metabolism computed empirically from the pH changes. (b) Open circuit voltages (electron voltmejer) with saturated calomel refefence elecirodes puncturing the mat (bottom left) ar@d across the intact !pembrane with laterally inserted platinLIM wire (top right). (c) Electrical current, top to bottom votential' difference. and external power drain under the loading foi maximum power Fig. 6. Graphs showing the responses of the b1tie-green algal mat to light (Armstrong and Odum, 1946) (From Armstrong and Odum, i�64; Fig. 1). 341 Light Intensity Redox Potential (millivolts) (Kilolux) CA 41h 0 0 0 0 0 0 0- N - 4b - Fig. 7. The relationship of redox potential to light. Each curve represents response in different blue-green algal mat microcosms (Sollins, 1969). 342 MCI Pond July 3-4,1962 O.17m 22 1/a. I I I . - I . - @ I @ 9.o_ p H 8.0- 7.0 i 15. 02 M@o . 5 Ohle car!ecled ----- T 0C 30- 0.3- -CO' 0.2- 0 0 ""@02 2 0- 0 -0.1 _0.T 00 06 12 Is 00 HOURS Diurnal record of pH, oxygen concentration, temperature, and carbon and oxygen metabolic rates, July 3-4, 1962, in the blue-green mat pond. Oxygen rate was overcorrected for reaeration by using K, 1.5. Fig. 8. Measurement of productivity in the blue-green algal mat (Odum, Siler, et al., 1963). @pH 343 Mat Pond Aug. 5-7, 1962 pH Aug. 6 9- Aug. 7 3.0- Alkalinity E 2.0 - Z 1.0 27- Salinity %o 25- 23 00 06 12 is 00 HOURS pond. Diurnal record of pH, alkalinity, and salinity, August 5-7, 1962, in the blue-green mat Fig. 9. Diurnal change in properties above a blue-green mt (Odum, Siler et al. 1963). 344 approaches 1.0. Armstrong and Odum (1964) and Beyers (1966) found net production eqi@al to 0.80 mM C02/1/2 hr. and nighttime respiration equal to 0"69 mM C024/12 hr- under 1000 ft-cd. In 600 P-cd. Sollins (1969 observed net production ranged from 0.52 to 0.76 1 27' 02/m /d. while total dark respi- ration accounted for 0-55 - o.82 g 02/m d. The P/R ranged from .64 - 1.4 (R = .9). Similar measurements have been made by Odum and Wilson (1962),, and Armstrong and Odum (1964). The efficiency of production with respect to visible light ranged from 0-5 to 1.62%. Respiration and photosynthetic quotients may vary greatly over a short period of time. High RQ (1.24 - 3.1) and AQ (4 - 10) possibly reflect pro- cesses of delayed oxygen respiration and the asymmetry of the ca-rbon and oxygen processes (Odum2 Cuzon du Rest,et al.,1963)- The observed oxygen curve for the first three hours after sunrise remain close to zero suggesting that an anaerobic deficit of reduced com- pounds were being oxidized by the 02 as fast as it was being formed. The lower algal cells appear to store reduced substances as 02 deficits that are made up later. In the determination of productivity values for algal mats corrections should be made for this loss of dissolved oxygen so that diurnal 0 curves do not underestimate metabolism as measured by carbon (Odum, Sifer et al 1963). Respiration in blue-green mats is a function of the oxygen content during the night and probably also dependent on oxy en tension during the day (Solins 1969). Respiration is greatest about 1@2 hour after dark (5-7 mg. 02/1 hr.) but drop ( 1.0 mg/1 hr.) in the early morning. It is probable that respiration is also high during maximum photosynthetic activities. Under favorable conditions the chlorophyll a content is comparable to some terrestrial forlsts (Odum. 1967b; Odum et a (1958) record values from 0.28 to 0-75 g./m. while Sollins (1969) has measured values up to 2.6 g./m.2 in the top layers.) During unfavorable conditions the chlorophyll a content declines readily and there is remaining a high ratio of carotenoids. Nitrogen fixation is also well documented among marine blue-green algae but it has not been studied in the algal mat system (Stewart 1962). Reproduction and Maintenance When patches of surface mat are lost the newly exposed surface quickly assumes a crustal character. lqngbya is positively phototrophic in moderate light and possesses some motility (Sorensen and Conaver,1962).- The surface mat and open spaces between mats may also be repopulated by hormogones which are bouyant in high saline water. The extreme diurnal range from aerobic to anaerobic conditions and the varying salinities are undoubtedly the most important factors in controlling 345 biota. Anaerobic night conditions restrict consumers and result in the deposition of organic matter (OdumSileret aL.,l963). The biota associated with the algae may also play an important role in maintainance of the mat. In microcos'ims the grazing action of dense populations of water bugq caused-the mat to lose form and become balls of blue-green algae (Odum 1967b). Where the surface water is deep'enough for fish, th6 carnivore adtion of C;MLino@jon onanimal consumers of the blue- green mats acts as part of a self-regulating machinery that permits the mat to hold-its organization. .Chapter B-1 MANGROVE SWAMP SYSTEMS Edward J. Kuenzler The University of North Carolina Chapel Hill, North Carolina 27514 INTRODUCTION Long stretches.of low-lying tropical and sub-tropical coasts are bor- dered by dense thickets or forests called mangrove swamps. These swamps dominate the world's coastlines between 25*N and 25*S Lat.; on the east coast ,of Africa, in Australia, and in New Zealand, however, they extend 100-15* still further south and in Japan they reach about 7* further north. The brackish waters of estuaries give mangroves their best growth conditions, but they are also well developed in regions of pure sea water, around hypersaline lagoons and salt flats, and up rivers and stre where salt water only occasionally reaches. Thus mangrove swamps on some coasts may be only a narrow fringe whereas elsewhere they spread many miles inland up the tidal rivers. Mangrove swamps are distinct vegetation- al zones dominated by a few species of moderately large evergreen trees. The term "mangrove" best applies to the whole swamp association, but it is also used in reference to particular species of trees in the swamps.. The salient features of mangrove trees were clearly stated by Davis (1940a): "Mangrove plants are typically adapted to fixation in loose, wet soils, a dominantly saline habitat, and periodic submergence by tides. They exhib- it different degrees of viviparity of the fruits and seeds and typical xeromorphic adaptations, and have respiratory roots". Mangrove trees so dominate the swamp and have.such interesting properties that the autecology of the trees themselves.is fairly well known whereas the ecology of asso- ciated plants and animals and the energetics of the whole ecosystem are not yet thoroughly understood. This report concerns mangrove ecological systems, including the dis- tribution, ecology, physiology, geological role, and human use and disturb- ance. The mangrove swamps of Florida and Puerto Rico are the main subject, but information from other regions will be included. Appreciation is.expressed to Mr. Henry N. McKellar for library assis- tance and to Dr. H. T4 Odum and Dr. William E. Odum. for critical.reading of the manuscript. Field observations in Ecuador and the Galapagos Islands were made during Stanford Oceanographic Expedition 17 with support from National Science Foundation Grants GB 6870 and GB 6871. Dr. L. G. Hertlein and Mr. D. Chivers kindly identified mollusks and crabs.- 347 DISTRIBUTION In the United States, the most extensive natural swamps occur in Florida where they cover about 675 square miles (Craighead, 1964). Their best development, in the Ten Thousand Island region and further southeast around Cape Sable (Fig. 1), produces a mangrove forest continuous along the coast and extending inland for eighteen or more miles along the water courses (Spackman et al., 1964). Three species of mangrove treesi red mangrove (Rhizopho@r_a';_aingle , black mangrove (Avicennia germinans), (=A. nitida; Moldenke, 1967), and white.mangrcAre (Laguncularia racemosa) dc;@Lnate the region; buttonwood (Conocarpus erects), although not a true mangrove, is important in the transition zone between the swamp and up- land vegetation,(Davis, 1940a). This region is unique because infrequently do red, black, and white mangroves grow so tall. A dense forest of mature red and black mangroves almost 100 feet in height stood here until the violent hurricanes of 1935 and 1960 (Davis, 1940a; Spackman et al., 1964). Further east, mature mangrove swamps are still well developed in the Bis- c4yne Bay--Florida Bay-Florida Keys regionbut they decline northward toward Jupiter (Fig. 1); they are unimportant beyond Cape Canaveral. On the Gulf of Mexico coast mature swamps decline toward Fort Meyers; Rhizo- phora becomes,much less important further north and Avicennia'dominates the swamps. The scattered thickets along the north coast of the Gulf of Mexico and in the Laguna Madre of Texas are composed of Avicennia bushes (Price, 1954 b). There are still extensive red, black, and white mangrove and button- wood swamps in Puerto Rico, although the earlier coverage had been re- duced to about 16,000 acres by 1940 through unwise exploitation and through habitat destruction by agriculture, dredging, garbage dumps, and real-estate development (Holdridge, 1940). Rhizophora mangle from America and Bruguiera sexanRula from the Phillipines, introduced into the Hawaiian Islands in 1902 and 1922, respectively, have become well established and are extending their range (Walsh, 1967). ZONATION OF MANGROVES The different species of mangrove trees sometimes grow in randomly mixed associations, but usually different species dominate certain bands or zones which are clearly delimited from the others. This characteristic zonation pattern results from differences in rooting and growth of seed- lings and from various competitive advantages which each species has in the several gradients present from below the low water to above the high water lines. Davis (1940a) diagrammed a dross section (Fig. 2a) illustrating the zonal pattern in relation to elevation, tidal coverage, and type of soil in 348 ArOSSIbal.Eel '"Eft- U"I. San S" *$a" Sm" "aw 3ftr4 MWIA --------- --- ---- ------ .4 K j -------------- jW - - ------------- ------ OKEECH08CE _71 AM K-- ------------- #if -- --- -------- tk ---------------- --- --------- 01 0.(m -IN 1, X. t-dy d Iwl@, iM p% N A -------- -------- M m I, @ 01, sac. R. X @10 K I A MEMO\\ Z@' 7 111 MMIIII _4@ M@11 i a ... If @`Vl. F'Mr, IAMI w.d d E.1int i. L.- - Off Sil., W." I Wicat@* of dm-ftd kOM 0-'q 'ip at I-Pas'-phy -at Off MSft b.. Natty of fft T. Th.. =,d ... 0 F400ac- x, N SOL MR VIPLANAnCN vii x hw- 'W-t Off C@ -P "aA Wa 47@ QW-k taft d M-W-f ft 1. m-,c Wr CA PF SA BLE - .it' Ell MWVst k.V% h@t7 O.-t.4 .,t, C. Nk. at -d- wa -abl. W -t at thew ke" % of, a. 00-af@lf_ 10 40 M11.0 a Kv W.'f Fig. 1. Topographic-ecologic map of southern Florida (from Tabb., 1963). TROPICAL CONIOCARPUS RNIZOPHORA 349 rOREST TRANsmON ASSOCIES AVICENNIA CONSOCIES SALT-MARSH ASSOCIES Bur r0NWOOOj BLACK MANGROVES LEVEE R&D MANGROVCS or MA -WAR PEAT '57 MARL MARL a. UNDERLYING ROCK niTel del samn Y I/ \4 @y V Volk Bartholomea annul ata Aratus pisonii 'Sabellastarte magnifica Stenopus hispidus Crassostrea rhizophorae 6!=@:3 Stichopus. badionottm b. Littorina angulifera 06 Ascidi4 nigm F ig. 2. (a) Diagrammatic transect of the mangrove cormmities from the pioneer Rhizophora family to the tropical hammock forest, show- ing approximate tide levels and soil conditions usually found in a marl soil region (From Davis 194Q@,).(b) Diagrammatic verti- cal distribution of fauna in Puerta Rican red mangrove forest (From Glynn, 1964). 350 southwest Florida. Beginning at the right we see RhizoRhora mangle seed- lings that have sprouted in marl soil below the low tide level; these form the most seaward band. Rhizophora may be easily recognized by its arching prop roots and by the long slender seeds which geminate before dropping from the tree. The prop roots are the imost important attachment surfaces for seisile organisms in the intertidal region. To their left, on slightly higher intertidal peat soil is the mature Rhizophora zone; the prop roots of these trees are inundated by almost every high tide. The zone inland is composed of Avicennia trees growing on flat areas flooded by the higher tides (Fig. 2a). Avicennia has characteristic pneu- matophores. Large numbers of these slender appendages grow up from the main roots until they emerge from the mud; their respiratory function is discussed below. Still further inland buttonvood swamps and Juncus roem- erianus marshes form the transition band between the mangroves and either the tropical forest trees or the sawgrass (Mariscus jamaicensis), plants that are unable to survive significant amounts of salt. Laguncularia is found in all zones but usually not as the dominant; it is often most abun- dant near the brackish marshes between theAvicennia and Conocarpus zones. Glynn (1964) diagrammed the vertical zonation of animals at one place in a Puerto Rican swamp (Fig. 2b). Vertical zonation of attached algae is discussed below. The characteristic zonation and succession seen in Florida swamps is also present in many other estuaries, although the species may be differ- ent. For example, in Australia it is Avicennia. marina that pioneers and borders the sea while Rhizophora stylosa usually forms the second succeed- ing band (Macnae, 1967). The subterranean root mat and countless emergent pneumatophores of Avicennia are capable of holding the surface sediments firm, but Rhizophora seedlings sooner or later germinate in the shade of the Avicennia and eventually crowd them out (Macnae, 1967). Further up the estuaries, Rhizophora usually borders the stream bank. In East Africa Walter and Steiner (1936) found sharply defined zones with Sonneratia alba nearest the open water, then Rhizophora mucronata, then Ceriops Ca;dolleana, and finally Avicennia marina nearest the high ground. ENVIRONMENTAL FACTORS AND SPECIAL ADAPTATIONS Temperature Cold weather is the most obvious environmental factor which limits the geographical distribution of mangrove trees and, therefore, the dis- tribution of this type of ecosystem. Mangroves are tropical trees and no species is able to survive hard frosts. The minimum air temperature which they will survive is about 25*F-(Davis, 1940a), but Rhizophora seems less 351 resistant than Aviceania' perhaps because it does not sprout from the stump (Holderidge, 1940). The northern limit of these species varies from year to year, being pushed southward in cold winters, but moving northward again during warm years following natural dispersal of seeds and resprout- ing. The effects of environmental factors other than low temperature are difficult to separate and assess individually, but the most important ef- fects will be described here in order to try to evaluate their effects up- on zonation and succession in later paragraphs. Tides The influence of tides upon mangrove swamps is of prime importance. A large tidal range is not necessary, however; well developed swamps are present in Puerto Rico where the range is less than 1/3 m (Biebl, 1962) as well as in Australia where it exceeds 3 m (Macnae, 1967). Mangroves also line the upper reaches of rivers in the Everglades where the tidal ranges are very small (W. E. Odum, personal communication). In regions of small tidal range, wind may force sea water from one shallow basin to another (Davis, 1940a), or up or down an estuary, against the normal tidal flow. Although generally considered intertidal, mangroves,may cover a wider hori- zontal zone than just between the reaches of low and high water. Rhizo- phora communities, for example, reach into water almost constantly one to two.feet deep and Avicennia grows at levels flooded only by the highest spring or storm tides (Davis, 1940a). However, in areas where tidal range is large, the seaward margin of the swamp may be above mean sea level (Macnae, 1967) and a zone of bare mud extends down to below the low water line. Tidal action certainly is important in bringing salt water up the estuary against the downward flow of freshwater, and this salt water elimi- nates competition from fresh water species, both plant and animal. It is @the periodic return of the tides that keeps the soil saturated with water, contributing to its anaerobic nature. It also wets the epiphytic algae high on the prop roots. Tidal currents circulate particulate matter for filter feeders such as sponges, oysters, and barnacles; that which is left by the receding water provides food for deposit feeders such as snails and fiddler crabs. Many mangrove swamps produce large excesses of organic mat- ter and some of this is exported on each ebb tide. Finally the tidal move- ment of water is essential for upstream transport of invertebrate larvae and the seeds of the mangroves themselves. Although some seeds may drop and take root below the parent tree, many of them float away. Seeds of Rhizophora, Avicennia, and Laguncularia may drift for months before taking root far from their source, some upstream, some thousands of miles down the coast or across the sea. Salinity Mangrove swamps occur in regions of high, low, or variable salinity. Salinity appears to be of importance not because the salt is necessary for 352 the growth of mangrove trees but because it reduces competition from other species. Rhizophora, Avicemia, and Laguncularia have been grown for two to three years in salt-free water or soil (Bowman, 1917). In natural estuaries, flooding during the rainy season may expose them to nearly fresh water for almost half of the year; alternatively, evaporation during dry weather may create shallow ponds considerably saltier than sea water without causing damage. In Florida the mature Rhizophora swamps along the outer parts of low shores and on shoals in bays generally have a fairly constant salinity; further from the coast they may grow in brackish water, and still further inland unique communities of dwarfed Rhizophora grow in practically fresh water (Davis, 1940a). Egler (1952) suggests that the fires and hurricanes that periodically sweep through this zone destroy the woody stand and sawgrass marsh takes over; because Rhizophora is prolific and aggressive, it invades the marsh first, but may be followed by Avicen- nia to form a mixed stand again. on the other hand, the early growth of red mangroves is faster in salt water than in fresh waters (Stern and Voigt, 1959). Avicennia frequently grows on flats where evaporation of sea water concentrates the salt, and the soil water salinity may rise above 80*/oo; on the other hand, rain may dilute the surface water to very low values (Davis, 1940a). Laguncularia also is tolerant of wide salinity changes. The algae that grow on prop roots of Rhizophora mangle are able to survive in fresh water, sea water, and 4-fold concentrated sea water (Biebl, 1962). The invertebrates and fishes of the swamps are also relatively tolerant of wide salinity changes. Motile species may avoid sudden reductions in sal- inity by moving downstream or into deeper, saltier waters. Sessile forms, however, oust have physiological or behavioral adaptations that are adequate for most conditions. Unusual rainfalls resulted in mass mortalities of sedentary invertebrates on mangrove roots in Kingston Harbor, Jamaica (Goodbody, 1961). Giglioli and King (1966) showed the variations in soil water and soil chlorides at different depths in mangrove swamps of west Africa during the dry and wet seasons. In old, stilted Rhizophora soils, water content of the upper foot of-soil decreased from about 66% at the beginning of the dry sea- son to about 30% just before the rains (Fig. 3, curve) whereas the watPT content below one foot was about 40% throughout this period. Soil chlorides varied little during this period (Fig. 3, histograms), apparently because the high permeability allowed equilibration with the waters which flooded the region. In the somewhat higher Avicennia and Sesuvium soils, the high evaporation rate during the dry season caused the soil chloride to become very high (Fig. 3); this salt was eluted again during the rainy season. The deeper layers of Avicennia and Sesuvium soils contained considerably more chloride than the Rhizophora soils. The deep Avicennia soils increased in*chloride content during the dry season more than the Sesuvium soils (Fig. 3). Davis (1940a) made the following conclusions regarding salinity: 353 LEARLY DRY. ILMI D-DRY. IILPRE-RAINS. IV POST-RAINS. (12 a 1) 3a 4) (6) (10811) fk Rz.2 40. water -40 30- 30 Chloride 26- 20 90-10- .10 80_0_11 0 TO- TO Av. 60- 6C 'a --\j 50 3: 0 40- 30- 9C 30 20-80 .20 10- ?o to 0- 50 SeS. 50 40. 40 30. 30 20 20 10 -10 0 0 4 Depth betaw surface (ft) Sand Sitt May Fig. 3. The seasonal and vertical variations in the concentration of soil chlorides (histogram) and water content (curve) in soils under old Rhizophora,. Rz.2; Avice@nia., Ave and Sesuvium Ses. Soil texture down each profile is indicated by shading (from Giglioli and Kingj, 1966). 354 "l. Salinity fluctuates widely with the seasonal rainfall, and year- round studies are needed to determine the range of conditions in Florida. 2. Only a few salt-marsh and mangrove plants are halophytes that defin- itely depend upon high salinity. Most of the mangroves are facultative to a wide range of salinity. A brackish condition is most favorable for the optimum growth of mangroves. 3. Although the different species of the mangrove swamps and salt marshes have a wide range of tolerance, the aver- age salinity of the communities is fairly definite, so that zonation cor- responds to seasonal averages of the soil-solution and surface-water sal- inity. 4. The soil solution usually is more saline and fluctuates less than the surface water. 5. The highest salinity is found where the water level is close to the surface of the soil, with consequent high rate of evaporation. Some of the salt marsh plants withstand higher salinities than any of the mangroves. 6. Saline conditions of both surface water and soil water extend farther inland than the normal range of the tide. The low relief of the land prevents rapid leaching out of this salt." The ability of mangrove trees to grow in sea water is of considerable ecological and physiological interest. Harris and Lawrence (1917) reported that the salt content of mangrove leaves, especially Avicennia, was higher than that of sea water or of typical land plants-and suggested that this resulted from rapid transpiration. Two mechanisms for solving the salt problem are found in mangroves, salt exclusion by the roots and salt excre- tion by the leaves. Salt exclusion appears to be important in species of Rhizophora, Avicennia, and Laguncularia; there is less salt in xylem sap of ,these three genera than is present in sea water- although there is much more than in ordinary land plants (Scholander et Al.: 1962). The most recent theory (Scholander et al., 1965) suggests that the negative pressure gener- ated by transpiration in the leaves which draws water up the xylem is suf- ficient also to separate fresh water from sea water at the roots. This re- versed osmosis is therefore proposed as a mechanism for salt exclusion. On the other hand, the leaves of Aegialitis, Aegiceras, and Avicennia secrete' excess salt (Scholander et al., 1962). These mangroves are the least able to exclude,salt from the7T@o`t_s, but they have effective "salt glands" on the leaves that can excrete solutions containing 2-5% NaCl. This is an ac- tive transport mechanism (Atkinson et al., 1967). There is more secretion during the day, probably because of higher transpiration rates, but perhaps also because salt excretion itself is light stimulated (Scholander et al., 1962; Atkinson et al., 1967). The ability of Avicennia to exclude some salt at the roots and to excrete salt by the leaves permits its growth in hyper- saline areas. Perhaps the often higher salintiy of mangrove soils and peats than that of the overlying water (Davis, 1940a; Scholl, 1.965) may par- tially result from salt exclusion by the mangrove roots. The low transpiration rates of mangroves are an adaptation to growth, in saline waters. Rhizophora, Avicennia and Laguncularia all have simple fleshy, elliptical or ovate leaves. The structure of the leaves, especially the heavily cutinized epidermis and lack of stomata on the upper surface, 355 tends to restrict water loss (Bowman, 1917). The result is that average daytime values of transpiration for Rhizophora and Avicennia are 6.5 mg/dm.2 - min. and 2.5 mg/dm2 . min.,,' respectively, values that are low com- pared to those for other plants (mostly 10-55 mg/dm2 . min.; Scholander et al., 1962). Bowman (1917) found that the rate of transpiration of Rhi- zophora mangle decreased when exposed to higher salinities. Although the physiological drought of saline soils has necessitated this adaptation in mangroves which is similar to that of desert plants, low transpiration rates are sufficient if essential nutrients are abundant in the soil water. Nutrition of mangroves, however, has not yet been studied under natural conditions. Temporal Patterns Cycles of environmental changes are evident both on a short term (dai- ly or tidal) and a long term (seasonal) basis. The daily input of solar - heat and the regular return of tidal waters cause a fairly regular pattern of changes.in water depth, temperature, salinity, oxygen, and pH. These factors were measured by Orr and Moorhouse (1933) during winter in a pool in a mangrove swamp at the mouth of the Daintree River, Australia. The mangrove area was exposed at low-tide,.but flooded again at about half tide. The pool bottom was covered by fine mangrove mud, and a thick growth of trees covering the pool allowed only diffuse light to enter. The pool slowly drained during low water, but was refilled again beginning at about 11:00 p.m. and 1:00 p.m. on two successive days (Fig. 4a). Temperature went down at night until the pool was flooded again with warmer water; it went up most rapidly during the noon hours in spite of relatively weak sun- light (Fig. 4, b). Salinity was not affectedby-evaporation, as was true in another pool they studied, but only by the changes in the river water: sea-water mixture, increasing as the tide rose (Fig. 41 c). The'decline in oxygen and pH (Fig. 4, d, e, f), however, resulted predominantly from in si- tu utilization for animal and bacterial respiration. There was no signifi- cant photosynthesis to increase oxygen levels in the daytime, but oxygen was replenished when the pool was-flooded each time. Thus the dim light, ab- sence of algae, and abundance of organic matter in the mud make these man- grove areas large consumers of oxygen. In other mangrove pools, photosyn- thesis of algae may partially offset the respiratory oxygen requirement (Orr and Moorhouse, 1@33)_ The seasonal cycles of temperature, salinity, PH, and oxygen content of the water ina mangrove-bordered lagoon in Puerto Rico were reported by Mattox (1949). The annual temperature range was only from 25.5 0 to 30.50C. Salinity generally ranged from 34 O/oo to 39 O/oo; this small range is at- tributable to the fact that the lagoon is on the dry end of Puerto Rico and received very little runoff even during the rainy season. pH was nearly constant-@(7.4-8.2), but oxygen varied by a factor of two throughout the year. The oxygen content was lowest (3.5,mg/1) in late summer when temper- 356 2- (a) IN ,C zo it (C) $RUNITr Z8 Z6 (d) cc FrS LIM J too M 01,11"Y 51, 0 7-5 - M 7-7- M - 65 &7 84 --r--r I 6 7 8 a 10 of 1Z Z J 4 5 6 7 8 9 10 /1 Z J 4 5 PM A14 PAC jig. 4. The diurnal changes in the water of a pool in the mangrove swamp near the mouth of the Daintree River. (a) Depth; (b) temperature; (c) salinity; (d) oxygen content; (e) oxygen saturation; (f) pH value (from Orr and Moorehousep 1933). 357 atures were highest, and highest (7 mg/1) in the late winter. Oxygen con- tent of the lagoon was consistently lower than that of the open bay nearby, perhaps because of the continuous input of organic matter from the sur- rounding mangroves. Sediments Mangroves grow on a variety of soils, or even on rock if there are sufficient crevices into which they may fasten their roots. In Florida the primary soils are either calcareous marl muds, calcareous sands in the southern part, or siliceous sands further north. The fine grained marl muds are deposited mostly in protected waters whereas the coarser calcareous sands occur in regions having considerable current action (Davis, 1940a). Mangrove growth is generally better in the marl muds than in other pri- mary soil types. Rhizophora and Avicennia do well on most soil types except shifting sands where currents are strong; Laguncularia, however, thrives on higher sandy soils. Of great'importance are the secondary, organic soils of peat or muck that have been deposited in many places. Much of the peat was produced by the mangroves themselves and deep layers may cover any of the primary types or be found interbedded or mixed with marls or sands (Davis, 1940a). Peat soils several meters thick represent the accumulated plant growth of long periods of time during which decomposition was slow. The finding of Avicennia peat deposited over.Rhizophora peat demonstrates the same successional pattern, namely that Rhizophora is the pioneer, seen in the zonal pattern (Fig. 2a). Thornton and Giglioli (1965) made a detailed study of the changes in pH as various types of mangrove soils were dried; the pH usually dropped very low, but the amount of change depended on the soil type. Because of this, the fibrous peat soils developed by Rhizophora forests are not easily converted into agricultural land; drainage allows oxidation of sulfides and the resulting acidity prevents successful rice growth such as is possible on soils previously covered by Avicennia (Hesse, 1961b). Water Table and Soil Aeration The distribution of mangrove species is'related to the water level in the soil (Fig. 2a). The pioneer Rhizophora plants grow in water that aver- ages 16 inches deep, mature Rhizophora in water 10 inches deep, and Avicen- nia in water only 6 inches deep (Davis, 1940a). The actual water depth over the soil varies, of course, with the stage of the tide or the amount of re- cent rainfall, runoff, or evaporation, but the soils on which Rhizophora and Avicennia grow are usually saturated. The transition species Conocarpus, however, grows on soil where the water table is usually only about 4 inches below the surface and capillarity keeps the upper few inches moist. Aeration.is very slow in fine sediments that are saturated, and conse- quently mangrove soils are usually low or lacking in oxygen necessary for 358 respiration of the living tissues of the roots. Oxygen from the air is not primarily supplied through the soil, but through openp spongy passages in the roots. Above the mud, the prop roots of red mangroves have many small pores, called lenticels, and when low tide exposes these lenticels, oxygen passes in and diffuses rapidly to all parts of the living, buried root (Scholander, et al., 1955). Black mangroves do not have these prop roots, but their r7o-oCs-extend underground in all directions from the main trunk. To obtain oxygen, their roots send special structures, called air- roots or pneumatophores, straight up 20-30 cm above the mud surface. Dur- ing low tide, when the lenticels are exposed to air, oxygen enters and spreads down to all the metabolizing tissues of the roots (Scholander, et al., 1955). SUCCESSION Each species of mangrove tends to change the characteristics of the area where it grows; the new conditions may be better for another species which will then come in and supplant the first. This pattern of one spe- cies replacing another in time, called succession, is clearly seen in the distribution pattern in Florida (Fig. 2a). Colonization of almost constantly submerged shoal areas and the lower banks of tidal creeks usually begins when seeds of 'Rhizophora take root. As these pioneer trees grow, adventi- tious roots sprout from the stems to form arching prop roots; later drop roots also grow down from the horizontal branches until each tree has many stems. Some of these drop roots take root in water too deep for seedlings to prosper. The st and prop roots form a dense tangle and are encrusted with algae and with sedentary animals such as oysters and barnacles. Mar- ine benthic algae and two species of higher plants, Thalassia testudinum and Cymadocea manatorum. grow in shoal areas near the red mangroves (Davis, 1946a). Debris -istrapp-ed and sediments accumulate among the stems because of reduced water currents, and the depth of the water gradually decreases. Furthermore, organic soil (peat) formed by leaves, roots, and stems of Rhi- zophora itself also contributes to building up of the soil surface. Geolo- gical uplift or a general lowering of sea level may also be involved in raising the Rhizophor zone above its optimal elevation. As the water becomes shallower, growth conditions become more favorable for Avicennia. The Avicennia zone, then, tends to succeed the Rhizophora zone in time and in space (Fig. 2a, 5). The invading Avicennia and a variety of salt marsh plants (Batis maritima, Salicornia perennis, Monanthochl6e littoralis, Sporobolus virginicus, Spartina alterniflora, and S. spartinae) form a relatively open, shallow, swamp-marsh association whicl@_continues to accumulate debris, sediments, and organic detritus and consequently gradu- ally becomes still shallower and more stagnant. Dry periods cause salini- ties to go up, whereas rainy weather may wash most of the salt out of the region; salinity is therefore highly variable (Fig. 3). The Avicennia trees in some places grow to more than a foot in diameter, but in other 359 TROPICAL FOREST DUNLI CLIMAX ASSOCIATION 6---PINELAND EDAPHIC ASS SUBCLIMAX ASSOCIATION FRCSH-WArER NAP3H 7%ASSOCIE5 RHIZOPHI FRE.W / MARSH OCIJ5 OfAeH 0,640CAPPUS MARL PRAIRIE ASS 5 TRDANSITic AS50 Is ASSOCIE5 VE,,IN mArwe -7@F -. TIDE MANGROVE )I L AGUNCUI APIA CON 0 IL's RHIZOPHORA BQACKISH MARSH 40CIES A550CICS O@@ i AVICENM sA L r - ImMi S A 5 S 0 6@'S AMAN TIDE SC UB AIANCROV rAC1.1S MATURf OPEN JZOPHORA MEAN WArf,7- - - - - - - - - tow SALINE TIDE RHIZOPHORA FA 441Z Y MA,qAF ACUAR 4SSOCIF5 Fig- 5- Stneessional relations of mangrove communities and some of the associated plant commmities. Approximate tide levels are indicated (from Davis., 1940a). 140 C, 1rVTA&S1T0N IL 360 places they are only small gnarled bushes (Davis, 1940a). Continued ele- vation of the soil surface creates conditions wherein Avicennia does not replace itself and succession may proceed toward a freshwater sawgrass marsh association, a Laguncularia community, or a Conocarpus association which can still later be replaced by upland tropical forest or pineland (Fig. 2a, 5). Soil borings confirm the pattern of succession. Mangrove peat is found under upland hardwood forest soils, Avicennia peat is found under Conocarpus soils, and Rhizophora peat is found under Avicennia soils (Davis, 1938). If sea level rises or the land subsides slowly, accumulation of peat may keep raising the mangrove associations to a satisfactory height rela- tive to water level. Thick layers of peat are eventually laid down. How- ever, a rapid rise in sea level may force a retreat of all zones inland and peat deposits become buried under maritime sediments. Mangrove peat buried under calcareous mud on the bottom of Florida Bay and also about 1.5 miles off the well-developed modern swamps near Cape Sable is convincing evidence that mangroves are capable of moving landward as well as seaward, depending upon sea level changes relative to the shore (Spackman, et al., 1964). Eg- ler (1952) feels that the botanists have overemphasized the geological im- portance of mangroves. Without doubt, mangroves oppose the erosive forces of wind and wave and they may build up considerable layers of peat and sed- iments, but compared to large-scale physiographic processes they are rela- tively impotent. ASSOCIATED BIOTA The mangrove trees themselves are certainly the dominant producers in the swamps, but algae also are important, especially because their production may be much more quickly consumed by the mangrove fauna than the woody mater- ials produced by the trees. In Florida, open shoal areas below mean low wa- ter are often covered by tropical species such as Caulerpa, Acetabularia, Penicillus, Gracilaria. Halimeda, Sargassum, and Batophora .(Davis, 1940a; Taylor, 1954, l9Wo-a-T._ibove this region, on the intertidal muds one may find � thick growth of Vaucheria or Cladophoropsis (Taylor, 1954). There is also � subterranean algal flora composed of unicellular and filamentous blue-green and green algae (Marath, 1965). The prop roots of Rhizophora mangle have several zones of algae attached to them. In Puerto Rico, the permanently submerged portions of the roots often have rich growths of Acanthophora, Spyridia, Hypne , Laurencia, Wrangelia, Valonia and Caulerpa; the intertidal zone may be covered by species of Murrayella, Centroceras, Polysiphonia, Etiteromorpha, and Rhizoclonium; finally, there may be species of Catenella, Caloglossa, and Bostrychia at the upper limit of high tide (Almodovar and Biebl, 1962). Biebl (1962) showed that epiphytic algae of the intertidal zone received only 8% or less of open sunlight because of the.Rhizophora shade; nevertheless they survived full sunlight longer than 361 the epiphytic algae that'grow permanently submerged. Furthermore, the.in- tertidal epiphytics generally were more resistant to osmotic..shock, drying, and unusually low or high temperatures than were the submerged Algae; this hardiness undoubtedly is of survivdl value during low tide periods. Species of Bostrychia, Catenella, Calogl6ssa, and Murrayella form a characteristic association (Bostrychietum) on mangrove roots around the world (Post, 1936). Many kinds of animals are found in mangrove swamps, in sharp contrast to the low diversity of plant species. The most.important benthic marine animals are probably crustaceans and mollusks and most of these can be clas- sified as either.dep6sit or filter feeders. Fiddler ciabs (Uca spp.) in Puerto Rico frequently ate dominant in terms of biomass (Golley, tt al., 1962). The crabs on intertidal flats 'of mangrove islands in Florida bay include Uca pugilator, U.. speciosa, U'. thayeri and Eurytium limosuii; other species are abun- .,Aratus pisQnii, Sesarma cura6a6ense, and S. reticulatum dant in mangroves above-high water (Tabb, et al., 1962). At low water fid- dler crabs move out of their burrows to feed on surface deposits'; the bur- rows probably effect some aeration And.mixing of the soil (Davis, 1940a). Barnacles such as BalAnus eburneus attach to roots and stems where they can filter their food from.the water at high tide. Coon oysters (Ostrea frdns), also important filter feeders, are abundant on mangrove roots in Florida and the weight of their shells may eventually cause the root to break off. (Davis, 1940a). Another oyster, Crassostrea virginica, is important in the intertidal area and below the low water mark in Florida Bay (Tabb, et al., 1962). The dead shells and undigested food of these barnacles and oysters contribute to the sediments of the swamp. Several kinds of snails (Ceri- thium, Melogena, Cyoraea, and Littorina angulifera)-feed on material depos- ited on the roots or on the mud surface (Davis 1940a;.Tabb, et al., 1962). Some vertebrates of the Florida swamps include turtles, croco@d_il7es, alli- gators, bears, wildcats, puma, and rats (Davis, 1940a). Birds are discussed below. Other important consumers in Florida swamps are amphipods, isopods, the crab Rhithropanopeus harrissii, and fishes, especially Cyprinod vari- egatus, Mollinesia latipinna, and Floridichthys carpio; Odum (1970) gives food habits of more than eighty species of animals from the swamps. Mattox (1949) made an intensive study of the oyster, Crassostrea rhi- zophorae, which grows on red mangrove prop roots in Puerto Rico. Physical conditions in the lagoon water were mentioned above.' Associated with the oysters on these roots are many other marine invertebrates,--sponges, flat- worms, hydroids, bryozoans, annelid worms, barnacles, shrimps, crabs,. snails, clams, mussels, sea urchins, and tunicates., Thus, this association is a very crowded one, with each individual competing for space and, un- doubtedly, also for food.-- In spite of the crowding, however, the oysters reach market size in 6 to 7 months after setting. Glenn (1964) gave a pop- ular account of the distribution and natural history of invertebrates in Puerto Rican swamps; a sketch of vertical zonation of animals is shown in Fig. 2b. Warner (1967) described the life history of the mangrove tree crab, Aratus pisonii and Feliciano (1962) reported on the biology of Cardi- 362 soma g nhumi. The zonation of animals which parallels the plant zones was described by Macnae and Kalk (1962) in swamps of Mozambique, Africa. There the crabs Sesarma meinerti. S. eulimene, and Uca annulipes were present in the land- ward Avicennia marina fringe. In the zone characterized by Ceriops and Bruguiera plants, the crabs were Uca chlorophthalmus, Sesarma guttata, S. catenata, IlZograpsus rhizophorae, Paracleistosoma fossula, Eurycarcinus natalensis, Metopograpsus messor, and Macrophthalmus depressus. In the Rhizophora mucronata zone Uca urvillei, U. chlorophthalmus, and Ilyograpsus rhizophorae were found, whereas the crabs in the channels below the Rhizo- phora zone consisted of Scylla serrata and Thalamita crenata. Other impor- tant animals include the snails Littorina scabra and Cerithidea decollata on the lower branches of the trees, and Terebralia palustris and Cassidula labrella on the sediment surface. The very interesting mud-skipp@er fish, Periophthalmus; sobrinus was found on the muddy banks of channels in the Rhi- zophora zones, along with the sea cucumbers Holothuria parva and Chiridota sp. Many species of fishes, shrimp, and insect larvae are found in the channels and can move into the swamps during high water. Finally, barnacles and oysters (Balanus amphitrite and Crassostrea echinata, respectively) are abundant on the lower trunks and pneumatophores of the trees. Most of these animals do not obtain food directly from the mangroves but either filter their food from the water at each high tide or else they scrape off sedi- ments and surface debris to obtain organic matter. The mangrove trees in the.swamp, therefore, serve the animal populations more as a place to live than as a direct source of food. Hence Macnae and Kalk (1962) postulated that the animals were "only fortuitously associated with mangrove trees and that their distribution is controlled by: (i) level of water table, (ii) resistance to water loss, and (iii) correlated with this, the demand for protection from the sun, (iv) the degree of consolidation of the substratum, and-(v) the availability in the upper layers of the substratum of a micro- flora and microfauna and of organic debris suitable for food." These fac- tors, however, seem to be very powerful and there is a remarkable resem- blance between the faunas of similar areas in Mozambique and in'Java (Ver- wey,, 1930; Macnae and Kalk, 1962). Two other factors ' the strength of current flow and turbidity of water, are probably important in determining whether filter feeders are more im- portant than deposit feeders in mangrove swamps. In the Galapagos Islands I observed that strong flows of water permitted development of filter feed- ing oysters, mussels, and barnacles (Ostrea palmula, Isognomon chemnitzianus, Brachydontes AR., Balanus trigonus (?), and Tetraclita squamosa whereas in quiet-backwaters the most important animals were predaceous or deposit feed- ing cribs and snails (Uca galapagensis. Leptodius snodRrassi. Ozius tenui- dactylus, Mithrax nodosus, Chiton sulcatus, Thaisg2., and Mitra tristis.) A great deal of work remains to be done in the Florida mangrove swamps, not only to determine distribution patterns, but also to measure environmental 363 requirements, biomass of the important species, food chains, energy flow, and nutrient cycles. Birds are abundant, conspicuous, and probably important in mangrove swamps; in Africa, Cawkell (1964) reported 45 species whereas in Surinam (Haverschmidt, 1965), and Trinidad,(French, 1966) about twice as many were found. Approximately half of the species utilize the swamps for nesting activities and the others feed there or congregate there in large communal roosts. The food resources of the birds are varied. Many (egrets, herons, ibis, ducks, kingfishers, crab hawks, stilts, and pelicans), feed on estua- rine fishes and invertebrates, others (fly-catcher, woodpeckers, wrens, swallows, and warblers) feed on insects in the forest, and a few (doves and blackbirds) feed on seeds outside the swamps but return for roosting or nesting. The mangroves themselves and their fruits, however, do not supply nutriment directly and the food supply for birds, like that of the other animals, comes predominantly from marine life in the channels or on the mud flats. The dense nesting colonies in some areas may harm the trees physically;"put the excreta probably is of some benefit. The plankton of mangrove areas has been studied to only a limited de- gree. It probably contributes only a small amount to-the total primary productivity but it does constitute, with detritus, the diet of filter feeders and, after sedimentation, deposit feeders of the swamps. Mattox (1949) found a relatively low (compared to temperate waters) but constant amount of plankton in a Puerto Rican lagoon. The samples were dominated by diatoms, especially species of Thalassiothrix, Chaetoceras, Nitzschia, Skeletonema, and undetermined filamentous types. Animals such as ciliates, f,oraminiferans, copepods.' and invertebrate larvae were present in smaller numbers than the plants.' Very large quantities.of organic detritus were also present in the water and'this detritus was found along with phyto- plankton in the stomachs of oysters growing on mangrove roots. Davis and Williams (1950) found@a wide variety of both phytoplankton and zooplankton in Florida swamps. He postulated that fresh-water forms are eliminated when- ever salinities increase sufficiently and that salt-water forms similarly decline during low-salinity periods. Reinvasion and growth restocks each population when conditions permit. Thus inability to endure salinity stress distinguishes much of the plankton from the mangrove trees, attached algae, and estuarine invertebrates. Studies of standing crops and of productivity would contribute substantially to our knowledge of energetics of the whole mangrove swamp ecosystem'. PRODUCTIVITY Mangrove forests are among the most productive of all estuarine eco- systems. Golley et al., (1962) made a study of the structure and metabolic 364 rate of a red mangroire forest in Puerto Rico. The mean weights of various parts of the trees from the top down, expressed as grams dry weight/m2, were: 778 g of leaIes, 1274 g of branches, 2796 g of tree trunks, 1437 g of prop toots, and about 5900 g of roots. The animals of this Rhizophora swamp weighed only 6.4 g/m . About 80% of the leaves were between 4 and 8 m above the forest floor; they were exposed to the brightest sunlight and intercepted about 80% of the light (Fig. 6a). Shade leaves and seedlings were less abundant and were exposed to lower light intensities. About 89% of the photosynthesis was carried on by the sun leaves, and the gross pro- duction in May amounted to 8.23 g of carbon/m2 per day (Fig. 6b, right half). Gross production of this magnitude is characteristic of a fertile ecosystem. In other words, this red mangrove forest fixes as much energy as many other estuaries, eutrophic ponds, evergreen forests, or good farm- land (Odum, 1959). Mangrove sun leaves accounted for most of the respir- ation also; oxygen consumption through the lenticels of the prop roo ts was also high, reflecting the respiration of the underground roois (Fig. 5b, left half). The export of particulate organic matter was relatively large. Not shown in Fig. 6 are amounts of organic matter in leaves,that fall to the soil surface (0.65g C@m2 . day), the organic matter converted to wood for tree trunks 0.4g C/m ' day), and production by algae in the mud sur- face (0.38 g C/m * day). Animal respiration 0.082g C/m2 - day) was a very small part of the total. It appears from the close balance between photo- synthesis and respiration that this forest was not making rapid net growth during the study period. Other workers (Holderidge, 1940; Noakes, 1955) reported wood production of Rhizophora spp. can be at least 10-fold more rapid than that measured by [email protected]., (1962). These higher rates of wood production would place Rhizophora among the moderately fast-growing tropical-hardwood species. Leaves and twigs constitute a substantial portion of the annual pro- duction of mangroves and they form a major source of detritus for the aqua- tic food chains of a swamp in southwest Florida (Heald, 1969). Only about five percent of the annual leaf production was consumed by terrestrial ani- mals. Some leaves fell throughout the year, but many more dropped in summer than in other seasons. Red mangroves, the dominant in this swamp, dropped about 880 g (dry weight)'of leaves, twigs, and other debris annually per square meter of forest; this amounted to 570 g/m2-yr for the total area of the swamp, including 'Open water areas (Heald, 1969). Red mangroves were the biggest contributors to the debris in the swamp; phytoplankton, Juncus and Mariscus marshes, and atiached algae were only small contributors to the total prod6ctivity. The Oebris decomposed into detritus, the most ri- pid rate of-deiradation being found in brackish water and slower rates in fresh water or subaerial conditions. Although the amount of debris remain- ing became less and less, the amount of protein increased from 3% to 22% in one year, presumably because of the buildup of bacterial and fungal pop- ulations (Heald, 1969). Detritus levels in swamp waters we're high (49-93 mg/1) from November through February, the beginning of the'dry season, and 365 DRY LEAFBIOMASS LEAF AREA CHLOROPHYLL A LIGHT INTENSITY TOTAL 1017 GPA/M2 TOTAL 4AMVTOTAL 1.19GM/101 SUN UN SUN w 5' LEAVES LEAVES LEAVES SHADE LEAVES a, NGS 100 200 1.0 0.4 5000 GM /M3 M2/0 GM M3 FOOT CANDLES RESPIRATION a LOSSES GROSS PHOTOSYNTHESIS 12 MR RESPIRATION CORRECTION NET .63 1.73 PHOTOSYNTHESIS SUN LEAVES 3.04 1.52 3.45 SHADE LEAVES AS .16 .12 SEEDLINGS -08 SEEDLINGS .12 PROP ROOTS+ 2.03 j16 24 18 SOIL SURFACE SOIL R.IN AIR ------ SOIL R. IN WATER TOTAL R - 9.16 TOTAL P 13.23 b - IL 5 4 3 2 1 2 5 GM C/142/DAY Figo 6. Red mangrove forest in May. (a) Vertical distribution of leaf biomass in enpi . (b) .. leaf area., chlorophyll a. and light I t ty Rates of photosynthesis, respiration., and export (g C/16day) (from Golley.. et al., 1962). U@N U@N [LEA ES LEAVES LADE Ll SEEDL I @ tI 6 _12 .08 366 were low (2-23 mg/1) during the rest of the year. From 35 to 60 percent of the total suspended matter in the swamp waters came from red mangrove debris; sawgrass, Juncus fecal material, and organic aggregate constituted the remainder (Fig. 7). About half of the annual production of debris was transported to nearby marine bays. The final steps in the detritus food web were delineated in the same swamp system by W. E. Odum (1970). He examined the stomach contents of more than eighty species of animals and on this basis classified them into appropriate trophic levels. The primary food source for the aquatic animal community was vascular plant detritus, mostly from red mangrove leaves. The major flow of energy to mangrove swamp animals is from mangrove leaves, via degradation and protein enrichment by fungi, bacteria, and,protozoa, to a large group of omnivores (Fig. 8; Odum, 1970). These animals ingest some algal material along with the mangrove detritus, they re-utilize some fecal matter, and they prey upon each otfier. They, in turn, are preyed upon by gamefishes such as tarpon, snook, ladyfish, grey snapper, sheepshead, spot- ted seatrout, red drum, crevalle Jack, gafftopsail catfish, and jewfish. The production of gamefishes is thus directly linked, by way of detritus feeders, to the productivity of red mangrove trees and destruction of man- grove forests will ultimately result in the decline of these fishes (Odum, 1970). Unfortunately, few other studies of mangrove swamp productivity have been made and it is not yet possible to report the productivity of other species, nor the effects of season, sediment type, salinity, or other environmental factors on the rate of organic matter production by mature forests. Of considerable ecological interest is the fact that virtually all of this primary productivity is carried on by a sing'le species, just as in temperate salt marshes Spartina completely dominates and is highly pro- ductive. Furthermore, remarkably few animals in the swamp subsist directly on living mangrove tissues; most of the organic matter fixed by mangroves is either deposited as peat, partially decomposed and consumed in the form of detritus, or exported from the swamp by river and tidal currents. The processes of organic decomposition, detritus production, and nu- trient regeneration are important. The slow diffusion of oxygen into sed- iments results in slow breakdown of organic debris and eventually peat de- posits are formed in spite of tropical temperatures. Kohlmeyer (1968) re- ported that true marine fungi grow on the submerged portions of.Rhizophora prop roots and that indigenous floras exist; Trematosphaeria mangrovis is found in Africa on Rhizophora racemosa whereas.Didymos_phaeria rhizophorae is found in America on R. mangle. 367 so- Mangrove Detritus --------- Sawgross 70- ............. Juncus Fecal Material and Aggregates 60- Ui -J d- 2 < 50- U) -J 40- U- 0 z LL) 30- Li a. 20- 10- J M A M N' D' 1968 Fig. 7. Percentage contribution of four major sources of detritus in estuarine water samples (Heald, 1969). 368 @0 FUNGI PHYTOPLANKTON BACTERIA a PROTOZOA BENTHIC ALGAE CRASS HARRACTICOID COPEPOD 81 LVE MOLLUSC AMPHIPOD INSECT LARVAE NEMATOD GRASS) 0 SHRIMP SHEEPSHEAD MINNOW MYSID 2ND CONSUMERS Fig. 8. Diagram of. the detritus-based food web,. The omnivorous detritus consumers ingest small amounts of living algae along with large quan- tities Of vascular plant, largely Rhizophora, detritus. Much detrital material recirculates in the form of fecal matter (Odum, 1970). @F@@G 0 rN U I BA T E P OTO@ R 369 HUMAN USE AND DISTURBANCE Morton (1965) summarized the commercial uses of Rhizophora mangle: tannins and dyes for several purposes; durable and water-resistant timber for residential and boat @on'struction, for pilings, hogsheads, and fence posts; wood.for high-grade charcoal production; and various medicinal uses, teas, And livestock feed supplements. Moldenke (1967) reported similar us- ages for Avicennia germinans; in addition, it produces an abundant nectar that results in a clear, white honey of some importance (Argo, 1963). Holdridge (1940) described the utilization of timber products from the Puerto Rican species. mangrove swamps, with their dense tangle of firmly implanted roots, greatly reduce.hurricane damage (Davis, 1940a). Although many of the trees may be defoliated, killed, broken off, or even swept away en masse by se- vere storms (Craighead and Gilbert, 1962); the damage to the coast is cer- tainly less than if the swamps had not been present. The transplantation of mangroves to Hawaii, mentioned above, was for the purpose of erosion prevention (Walsh, 1967). The slow, long-range accumulation of sediments, and peat production, and eventual land building is certainly to be consid- ered another human value of mangrove swamps. Florida mangrove swamps serve as nursery grounds,for many animals ape- cies of economic importance--menhadden, black mullet, spotted sea trout, snook, tarpon, red drum, mangrove snapper, pompano, and pink shrimp (Al- lin, 1966b,Tabb and Yokel, 1968). Sports fishermen as well as commercial fishermen are interested in preserving the total area and the quality of the.environment'in order to maintain good catches of fish. Edible oysters growing on the boitome. of shallow bays or on the mangrove prop roots are also harvested in some places. Mattox (1949) calculated that about $5,000 worth of,oysters' were taken annually from the mangrove roots of Laguna Rin- con in Puerto Rico. Large land-crabs are collected for human consumption many places in the world; Feliciano (1962) estimated the market value of Cardisoma. kuanhumi in Puerto Rico to be $70,000 per year. The value of the swamps also includes their attractiveness to tourists. The uniqueness of this part of.Florida was the rea 'son for creation of Ever- glades National Park. There are 99 species of aquatic and wading birds, most of which inhabit the mangrove edges of the park or the keys of Florida Bay,.and numerous other interesting animals--alligators, crocodiles, manatees, ottersi In 1965 Everglades National Park had 226,000 boaters, most of them fishermen, over 100,000 campers, picnickers, and bird-watchers (Allin, 1966a). These people came to enjoy the rich wildlife associated with mangroves or dependant upon conditions resulting from the mangrove swamps. Nowhere else in the United States can this wildlife be seen and enjoyed in its natural habitat. 370 The mangrove areas of Puerto Rico have been greatly modified by human activities. About one-third of the original mangrove area has been com- pletely destroyed by overcutting, dredging and filling, garbage dumps, or housing developments (Holdridge, 1940; Wadsworth, 1959). These pressures, plus the rapid increase in domestic and industrial pollution, are consid- ered to be very harmful to optimal utilization of the swamps for food pro , duction,,tourism, and recreation in Puerto Rico (Federal Water Pollution Control Administration, 1968d), Human activities in Florida have not yet done irreversible damage to the major mangrove areas and their biota, but only far-sighted planning and broadly-based conservation practices will prevent ill-advised "development", gradual attrition, or destruction by altering water-flow patterns. Some of the lessons learned from other estuarine areas, for example New England salt marshes, are applicable. It is not possible to destroy a portion of the mangrove swamp every year for decades and yet expect the ecological sys- tem to remain the same size and the components to flourish as before. Eco- logical theory says that reduction in size of a habitat reduces the number of species--the diversity--of the system. Although this reduction in di- versity may not be apparent, or'seem important, to the layman, reduced va- riety of components. in a system usually leads to less stability of the whole system and often to a loss of important species. The slow destruc- tion as agricultural and residential developers move southward in Florida is serious. Even more serious is the potential for quick and perhaps per- manent destruction resulting from mismanagement of the fresh-water drainage from the Florida Everglades. It is this water at the right season and of sufficient volume that has permitted the magnificent mangrove association to develop. Tabb (1963) has thoroughly documented the effects of 1. this mis- management of water in the Everglades and Tabb and Yokel (1968) warn against allowing damage to occur elsewhere. Reduced water volumes and improper timing during the last few decades have already caused great harm to the Everglades National Park and its fauna, especially the alligators and the beautiful spoonbills, egrets, .ibis, herons, Everglades Kites, and bald ea- gles that help make this park famous. The threat to the mangrove trees from reduced freshwater flows is not so immediate because of their wide salinity tolerances, but some of the valuable commercial fisheries crops, such as,the pink shrimp, may fail to mature in the Everglades 'estuary under changed conditions (Idyll, 1965b, a). Few realistic appraisals,have been made of the human values of mangrove swamps and, unfortunately, they have in the past been relegated, along with salt marshes, to the category of wastelands. Destruction by dredging and, filling, by garbage dumps, or by housing developments, have usually been re- garded as improvements. Numerous real values and benefits'such as commer- cial products, shore protection, food production,- recreation, and aesthetic beauty do accrue from the intact swamps, however, and it is unfortunate that these values may not be appreciated until ihey are lost. 371 RESEARCH NEEDS This survey of present knowledge of mangrove swamps shows clearly that, although we know many details about different swamps, it is impossible to assess the overall structure and metabolism of any area anywhere in the world. We need more detailed information about zonation and succession and their causitive factors,-about physiological adaptations to,salinity and anaerobic sediments, about nutrient requirements and productivity of the trees and the attached Algae, about the food webs, growth rates, and life tables of the,mangrove animals, about,the.p@ankton and detritus of swamp wa- ters and the relationships of the plankton to the benthic animals, about the final decomposition of organic matter by microbes, and about the human val- ues of mangrove swamps. However, instead of continuing to learn in,great detail different,things in different parts of the world,'we now need to bring together a few large teAms of,speciali6ts who can' do a thorough study of the structure.and function of a few areas. The study of structure should include dail physical And chemical factors in and seasonal measurements of the airlwater, and sediments, and population studies of plants andlanimals, i.ncluding the plankton and the biota of the sediments. The study of func- tion must include not only the metabolism of the individual organisms, but also the nutrition and metabolism of natural associations of organisms on the largest scale possible to avoid influencing the measurement being made. It is only by means of such large-scale studies and the synthesis of the results that we can begin to understand precisely how the whole system works, how it interacts with surrounding systemg such as the land, the ri- vers, or the open sea, and how the system reacts to the various pressures which mankind exerts. Without such understanding mankind can quickly.do serious damage to the mangrove ecosystem and unknowingly lose a valuable resource. 372 Chapter B-2 CORAL REEFS Louis H. DiSalvo and H. T. Odum University of North Carolina Chapel Hill, North Carolina 27514 =ODUCTION Coral reefs are tropical shallow vater ecosystems (Fig. 1) growing on their own limestone substratum and requiring bright light, stable high salinity, and temperatures above 700 F. Reef-building plants and animals continuously remove calcium and caxbonate ions from seawater to produce skeletons which are incorporated into the limestone base. Attached to this substratum, crawling upon it, hidden within it,.or swimning in close prox- imity are nyriad creatures of bizarre color, form, and behavioral adaptation (Fig . 2). Diverse and ornate populations make coral reefs the most esthetically pleasing of underwater comuanities. The unusual physical structures and com- plexities of biological interaction have no rivals among the other coastal systems. The principal reef builders of the present geologic era are the hermatypic corals. These corals contain, in the cells of the inner layer(Fig. 3) microscopic unicellular algae called zooxanthellae whose photosynthesis con- tributes to food and skeletal formation. Other important reef builders are some red and green algae which also produce carbonate skeletons. The most important of these are the encrusting red algae such as 'Pbrolithon (Fig. 4) which were highly important in reef building during the geologic past and persist as dominants in wave-swept buttress zones of many present day reefs (Fig. 5)- Non-hermatypic corals occur in deeper, darker waters (Fig. 6). Although there are many coral species which can grow and calcify in deep,cold waters, true coral reefs are not formed below a depth of 100 meters. Teichert (1958) reviews the occurrence and distribution of deepwater coral banks (See Fig. 12A). The coral-algal symbiotic association a-ids bhe formation of massive reefs because of the unique advantages of the association. The symbiotic algae are protected in the tissues of the coral animals which are themselves protected by highly specialized cell producis, the nematocysts (stinging organelles). The zooxanthellae are held up to the light by the basic structure of the coral, and further exposed in many corals whose polyps are extended from the corallum, during the day (Wainwright, 1967). Figs. 7 and 8 show the coral heads' uptake of nutrients(y,onge',1931;K@Lwaguti,195.3,1954).Algal photo- synthesis and concomitant respiration by the coral are mutually beneficial. Algae typically produce oxygen and food contributions for the coral animal@ whereas the coral releases carbon dioxide,phospho:rus,nitrogen compounds.,and other waste products used by algae to construct organic materials-With radioactive -1. 4. 13-j !,J,@N.NuLA o 0oi, (a 0 )-1 (D Uq IT C+ ID (D 0, p. H 0 H Fj C+ P. CERVICORNIS ZONE 0 R P H (D 0 (D cc++o Ho 0 Id 0 (D (D P FJ P 9 (D co (jq tq 0 -0 LA C F- 0 JOUT RIESS ZON Wo. 1@ (D9 10+ kZ Fj oV) Id D P, C'- '(D (D F1 jq 0 0 (D i@t I LOWER PAL ZONE' 7; ATA Pi F4 W F1 P. F1 0 (D (D 0 P, F' t-, 0 ci !j F.0 0 EA 0 ON.. V\N% CIA o 0 ilf 1 1 0 ci c-F NTHvs, + 0 c-F 0 tj 0 P, P, 0 p H F-b m WEA Co (D 0 (D (D o r_n t 0 (D ul NO EEF cn A. F-b N FN F. % 374 coral feeder (parrot fish) 44L Doscyllus Crinoidea @Olyps Chromis coral Leptoconcha (snail) Goblodo Choetodonts Pomocentrids Aconthurids Lithodomus (mussel) Trapezia (Xanthidoe) boring Cyanophyceae Cryptochirus (Decapod) Coro/ U) v lpheus cc P chae 430 W Pyrgomo (Cirriped) Amphipod Serpulld (Polychost) 4Z@ A (n 0 cr Z Caprella Z W ry Z04 phiuroid ,r- Holothurion W P \ @, -p , U) W v tL Z cr Lobophytum Ui < (Alcyonaria) 0 > FE snoi Q Q Cb Echinold Tridacna oneEnone a pongii' nus ist Polycl6d re algou tunicates 11,.,,grouper Hourn a (1) Vermitid (Gastropo Asteroid- moray PREDATORS lioni P -pan 7Porolithon Protgz )acteria mantis 'fungi and/fungi shrimp Nematod ponge sipunculid iiiii id ascidia REGENERATIVE SPACES Fig. 2. Conceptual diagram showing a collection of organisms in positions they might assume as part of the reef community. The segments of the community are arbitrarily partitioned to show some trophic relationships. (Modified after Gerlach, 1961). A+@ > 9 W rn (a) 10 Life cycle of Symbiodirium microadriaticum. A, vegetative cell; B, vegetative U0 cell undergoing binary fission, producing two daughter vegetative cells; 0, vegeta- IQ tivo cyst, differing from the vegetative cell mainly in the thickness of the cell wall; D, mature zoosporangium, containing a F@maodinioid zoospore; E, gymnodinioid zoospore; F, aplanospore; G, cyst contaming two autospores; H, cyst containing developing isogametes (?);1, liberated isogametes (?); internal detail not shown. (After Freudenthal, 1962.) 7 V@ 500 showing cross section of the body wall (b) to show Fig. 3. A coral polyp (a), the basic unit Of the coral colony zooxanthellae in endodermal tissue. Zooxanthella enlarged (c) is shown with life cycle as it oc@urs in (b) 100 X laboratory culture outside the host. (a) Meglitsch (1967) (b) Yonge (1931) (c) Yonge (1963a) 376 @7.7 xl@ -d (a) (b) x x J I @ITV. z-' I I - wa=@It ittd ON . . . . . . (C) x (d) 50 x Fig. 4. Porolithon (Lithothamnion) spp. are important as producers of calcium carbonate and as cementing agents on coral reefs. (a) Shows thallus of an encrusting alga growing over a dead reef fragment, (b) and (c) show encrustations on other living algae, and (d) is a cross sectional view of the thallus to show reproductive structures (conceptacles) used for identification. Living tissue at the thallus surface leaves behind cell walls heavily calcified with high-magnesium calcite. (Oltmanns, 1904). 377 4 R SC N V, B Generalized sketch of seaward face and top of reef on windward side of Bikini Atoll. AR, algal ridge; B, buttresses or spurs; C, coral of reef flat; G. grooves; LTL. low tide-level; SC, surge channels; T. terrace (about 10 fathom). (After Muni, and Sargent, 1954.) Fig. 5. A wave stressed seaward reef typical of Pacific reefs. (Yonge, 1963 a NUMBER OF SPECIES 120 IC9 80 60 @URFACE HLRMATYPIC.40 20 NONSURFACE HERMATYPIC@\ 30 15 6 20 40 60 80 100 120 LAGOON SEAWARD SLOPE SCALE IN FATHOMS -Bathyrnetric distribution of species at Bikini Atoll. Fig. 6. Distribution of species with water depth over a Pacific atoll. The largest number of reef building,species occupy shallowest waters. The ahermatypic corals thrive where light becomes limiting for hermatypes. Wells (1954). C ++ from sea water in coelenteron -4 , E L A -3 E -2 -2 Er C CALICOBLASTIC F 6Tosynthesis. GASTRODERMIS _X_ 2 3 1 r Active -ZOQ@V!Iellae H.U" transport of 0 @2 Cd$ in cells 002 13 0'0 1 Q C METABOLICI 0 1) 0 E 0.01 E" C02 'COP@O 0.01 z CO HCOS- AWHY RRc.1 CALICOBLA5TIC EPIDEIRMIS ci 2 H@C 0, 2 3 Adsorbed on mucopolysacchoride-__ -0.004 X_ i n orgamcmembrane, 0.0041 X-----x Ammonium (B. D) and calcium (A. C) metabolisms of Balano. phyllia, Psammocora and Ortlastrea. expressed by circles, dots and crosses -C(a(HC03)- CC'C03+H2Co3- respectively, in the light (A. B) and dark (C. D). Decrease& or increases are 2 calculated from the data given in Table 1. (Ppf) (b) Fig. 7. Metabolic relationships of coral-algal symbiosis. (a) The possible relation between algal metabolisn Diagram (after Goreau, 1959a) showing possible pathwa3-3 of calcium a .ad and calcification of the coral host. (b) The carbonate during calcification in a reef-building coral. A diagrammatic cross- positive effect-of light on coral metabolism of section of the calicoblastic body wall at the base of the polyp is shown but the parts', calcium and ammonium. Balanophyllia (open circles) are not drawn to scale. The coclenteron and the flagollated gastrodermis containing has no zooxanthellae. (a) from Yonge, 1963a (b) a zooxanthella are shown at the top of the figure, the calicoblastic epidermis is in from Kawaguti (1953). the middle and the organic membrane with crystals of calcareous matter is at the bottom. The direction of growth is upward, i.e. calcium deposition is in a downward @ '3 E' direction. (a) OD Re.-,-el,.(aqe Phospharms ZI m 0 .g 5. 00 0) *0 0 rt PI 03 go pi m 0 0 0 m " rt 0 cr =1 0 aq I I-A m 0 @-u n m '0 ell ID H. 0 pi ZI UQ r. Sb rt C, rt A$ PTI m 0 p NH3in mgm R, -0 so M" r 0 0 o n 2. o a. 0 , :1 v cr- 0 = E* cwr 0 0 CL rt 71 E, CL r, m pi (r, JA 100- CL :r t3 x UC 380 tracers Mascatine (1967) showed that organic materials synthesized by the algae are released to the coral tissue, and Goreau (1.959b,1.963) showed light accelerates calcification. Photosynthesis uses carbon dioxide raising the pH as diagrq d in Figure 7. Kawaguti (1944) found that the algal symbionts of corals and several other reef organisms were dinoflagellates, illustrated in Fig' 3,. WLaughlin and Zahl (059)'have cultured these cells in vitro and described the life cycle. Goreau and Wells (1967) list 48 species of reef building corals for Jamaican reefs, which probably approaches the maximm nuidoer of reef building species for*the Caribbean region. Wells (1957) estimated that there were over 700 species of reef ouilding corals among the'typically more diverse Indo-klaciric reefs. A wide variety of coral skeletal forms exist, and these forms may be further diversified by morphological adaptations to waves and currents. Fringing Reefs, Barrier Reefs, and Atolls Coral reefs were classified generally by Darwin (1851) as a series of intergradation6 between initially formed fringing reefs, followed by development of barrierreefs, and finally atolls (Fig. 9). Reefs may arise either,on contiiiental footings or on islands which have arisen in the sea as a result of volcanic activity. Darwin presented the theory that coral reefs grow upward at a rate compensatory to the geological subsidence of volcanic platforms. A fringing reef, being the youngest geologically, may be found in many'intergradations from newly colonized lava flows (Doty, 1967c)to es- tablighed reefs (See Fig. 16). Barrier reefs sometimes occur wny miles offshore (Fairbridge, 1950) often enclosing a distinct lagoon between them- selves and a nearby land mass. Patch reefs may axise from this lagoon floor. An atoll is a coral reef in the form of a ring or semi-ring, delimiting a shallow (max. depth 359 ft) lagoon containing patch reef "knolls". Islands on atoll reefs axe secondarily derived from reef sediments. The largest atoll (Kwaialein) is 66 miles long and 15 miles wide with a land surface area of 6-3 square miles (@Iiens, 1962). The Florida,(barrier) reef tract is about 200 miles long while Australia's great Barrier Reef extends over 1000 miles. Atlantid.reefs are usually of the fringing type and axe not as well developed as.Pacific reefs. Three Caribbean atolls ha:ve been described (stoddaxt, 1962a). Fringing, barrier and atoll reefs are distributed in specific patterns related to volcanism throughout the tropical Pacific and Indian Oceans (Darwin, 1851)- Cores from drilling (Fig. 10) have documented the geologic history of some reefs, supporting the Darwinian hypothesis of reef growth and-basement subsidence. The relative rise in sea level from time to time in these records indicates that some reefs have existed for 100 million years or more. Geographical Distribution The distribution of reefs in most localities is determined by water clarity and other factors as presented in Fig. 11. The world distribution of reefs is illustrated in Figure 12. Northern limits of coral reef ecosystems 381 77 Fig. 9. Geological evolution of an atoll. According to the Darwinian hypothesis, fringing reefs grow around the edge of newly emerged volcanic rock (top). As volcanic platform subsides reef continues to grow upward enclosing a lagoon (middle). Finally, volcanic island disappears as reef continues to maintain itself at sea level. Maximum rate of reef growth is at outer edge. (Shepard, 1948). 382 FUNAFUTI E N I W E T 0 K 81KINI KITA-DAITO- MIDWAY JIMA K-18 F-1 E-I S R 0 '0 7- YLARS' T 0 -'6 8 ;Ltz 200- 1000 1114 400 TO 280 TO 11 -@4 TD25515 Soo C. ------------ - -3000 TOP OF EOCENE EXPLANATION 1000 LITHOLOGY (LEFT) * .... i*"d 'i ...... Co,boiactous clay God limestone 1200 Volta- Clay and conglomerate 4000 Basalt T0422Z ORILLING PROPERTIES (RIGHT) C3 Soft 1400 Ej Hold and firth 14800 TD4630 TO 2556 Total depth ln feet Summary of results of deep drilling on atolls in the open Pacific Ocean. (After H. S. Ladd and S. 0. Schlangcr, U.S. Geol. Survey Profess. Paper 260-Y (1960), fig. 287] Fig. 10. Results of rock corings used to determine geologic history of coral reefs. Basalt is volcanic rock upon which reefs originated. Presence of volcanic clay, conglomerate, and carbonaceous limestone indicates the conversion qf reef limestone by freshwater (rains) as might occur during drops in sea level during glacial periods. The deeply lying basalt is evidence supporting Darwin's theory of platform subsidence and reef growth. (Ladd et al.,1967). 383 PER CENT OF SURFACE ILLUM.INAT16N (MOTODA, 1939) 0 25 50 75 100 RADIANT ENERGY 9M C01.1CM?1hf (SVERDRUP ET AL 1942) NO.SPECIES OF HERMATYPIC CORALS AT BIKINI ATOLL 0 15 30 45 60 75 -90- 105 120 15 Ternperoture OC 0,,,er, cc// 30- 45 - 60 - Ct ct 0- Uj C3 90 105 r 120- TEMPERATURE, OC (MOTODA 1940) 14.0 16.0 18.0 20.0 22,0 24.0 26.0 28.0 30.0 3.0 3.5 -4.0 4.5 5.0 OXYGEN, CCIL (MOTODA 1940) Fig. 11. Graphic analysis of coral reef distribution according to depth, oxygen, temperature, illumination, and radiant energy. (Wells, 1957). 384 Geographical Latitudes z Sea leveli 8o* 70- 60* 50* 40- 30* 20* 10. Lu 0' Sea level too- Tropical coral reefs too 200- Hermatypic corals 200 Effective depth I' non-reef building 'Mir for C01core Cu ous of ce 300. 300 400- Extreme depth 400 = .,:-,O_rol:bonks 'Mir for c z 01c0reous of 500- . I "patches 0 500 2- 600- u -600 700- C, 700 800- -800 goo, 900 -Distribution of calcareous algae and of bermatypic and abermatypic corals in different geographical latitudes on ocean floor to depth of 900 feet. Distribution of North Atlantic coral banks and patches also indicated. Figure 12 a World distribution of coral reefs (Teichert,1958). DISTRIBUTION OF CORAL REEFS 700F SURFAM I A, - - --------- If TN 'N ......... kh, 70111 AC9 ISOTHERM - ----------- .-A map of the Pacific Ocean showing the distribution of coral reefs within the summer and winter ranges of the 70* F. surface isotherms. Major coral reefs are illustrated by hatched areas; the solid lines illustrate the approximate locations of the 70* surface isotherms during the summer in each hemisphere, and the dotted lines represent the some surface isotherms during the winter in each hemisphere. (After J. W, Wells. 1957.) Fig@ 12b, World distribution of coral reefs (Helfrich and Townsley, 1965)- 385 are appaxently determined by winter temperature and associated temperate phen- omena such as turbid, low salinity waters which move south along the Florida and Gulf coasts. Along the coast in the Gulf of 14exico reefs appear abruptly on islands near Tuxpan, Mexico off Cabo Rojo (@bore, 1959)- Offshore a coral reef system was discovered only 100 miles from Galveston, Texas (T.E. Palley, personal communication). Along the Atlantic coast a few patches of hermatypic corals exist, as far north as Cape Lookout, North Cjwrolina but reef systems are not formed (MacIntyre and Pilkey, 1969). Un the west coast, waters are cool due to upwelling, and conditions amenable to the growth of reef builders axe seldom encountered. Squires (1959) describes reefs found in the Gulf of California (Figure 13). In the United States, only Florida and Hawaii possess coral reefs as coastal features. Well developed reefs occur arourA the coasts of Puerto Rico, Panama, and the U.S. Virgin Islands. Some of the world's best reefs are found in the tropical Pacific on islands of the U. S. Trust Territories, Guam, and American Samoa. Fig. 14 is a detailed map of fringing reefs around St. John, U.S. Virgin Islands, a national park. Eniwetok and Bikini Atolls, U.S. Trust Territory of the Mxshall Islands,are among the best studied coral reef areas as a result ,of geological, biological, and chemical studies carried out during U.S. testing of nuclear weapons at sites on these atolls. Hines (1962 provides a general- account of these tests. Figures 15 and 16 show variations in self grown limestone platforms of coral reefs of the Indo-Pacific region. Fig- 5 is an enlarged view of an algal ridge also shown in Fig. 16a. Distributions of coral species are also shown. EXAMPLES Small Reefs of Puerto Rico Figure 17 locates patch reefs around the Commonwealth of Puerto Rico. The growth of reefs is favored on the dry southwest coast because the shores are protected from heavy winter waves and runoff and are favored by steady currents of clear water from the east. However, development of heavy industry with its-associated addition of turbidity-inducing wastes to these ocean currents presently forms a serious threat to the reefs. In Fig. 18.Glynn (1964) shows two animal associations found on these reefs. Changes in oxygen across these reefs was used to estimate photosynthetic productivity by Odum, et al. (1959), as shown in Table I and Fig. 19. Beyers (1963), using pH changes, studied the diurnal balance of photosynthesis and respiration of isolated coral heads from these reefs (Fig. 20). The graphs show the daily respiration rates to be dependent on the previous day's photo- synthesis. These results document high productivities as measured b day-night oxygen measurements on reef waters. Plant production of 29 g. per Y per d4y was recorded and respiration measurements indicated that the daily production was consu d the next night. -386 %to > > @Af > 0 Z C14 .A' 5 R A 0 > 2 > $ 0 W 0 Z > 2 > W ENCRUSTING NODULAR 0 GI8BOSF LOW 8,4NCHING W COLUMNAR K@O !@o Es 6 100 2@0 200 306 400 1010 KILOMETERS - 300 400 NAYARIT o 1@2 200 KILOMETER5 Distribution of the phenotypes of Porites californica Verrill. Fossil distribution is Numerical distribution of 13 shallow-water species shown only for the reef phenotype (symbols on representing the genera Pocillopora, Pavona, Psammocera, land areas). Poriges, A@traxgia, and Tubastrea. The size of the pie-shaped segment is prop;rtional to the number of species (also given numerically) present at various localities. Fig. 13. Reefs in the Gulf of California. These reefs are not well developed, and exist at the extreme northern limits of environmental tolerance for reef building@corals. Structural and species diversity decrease northward up the Gulf. (Squires 1959). 2D oc < m !@ 70 m 0 0 r- ED 00 0 K H. 00 A rt m 0 xo mr 's. 4-4 m cn H fD =1 c 3.z rt 0 0 r m4 rt L4 LE az !c, 74 It 1-4 n rq rt CE) m 0 m rri o z > on x z o). o I I z p. o 10 ME n T 3. -43. 0) m 0 + +++ +++ W 0) MC o "4 r < Ic Ll rn 'i z m Z,-A -4 ..... .. .... z xx ct mzso-=mcx (A i'm 0 C) (A rri CD rt m oc, 3.c 4z c Ph x V4 o Um ct 0 rt z m 4z If 388 A OULDER INNER REE OUTER OUTER ZONE OF CORAL HEADS ANCHORAGE CORAL ZONE .ZON MOAT FL AFT MOAT RIDGE A.lif- -ji, 4-,- --a'o on. Gentle slop. to, 700 ,or d% tt,6-5 tothoms kh q-th ,here head," of coral disappear YONGE REEF, OUTER BARRIER, AUSTRALIA Based on Stephensomand others,1931i Manton, 1935 B SHORE REEF FLAT BOULDER ZONE ;X1 ft"v- on, P-IfIr, AC-,,Q,V Zan, an. (proc 1 11 on. 501on. SANTA MARI A (GAUA) ISLAND NORTHERN NEW HEBRIDES Based a. Baker. 1908 C SHORE BOULDER REEF FLAT ZO .. ME so. CA... I... ...... M.11.1 on. tan, bt and- HOPE ISLANDS, NORTHERN GREAT BARRIER REEF . ...I Based an Hedleyond Taylor. 1908 D E MANGROVE NNE R OUTER SHINGLE S.A.P R AMPART RAMPART RAMPART LIEWARDISLANO MOAT WINDWARD Ltolo be, 1-1 P",/,. Z5 Actopord humdisA. decpienj, A. abrofanoides Mo.,- P.Cwop ...... do-, (en-111 PO- Rho ,a 10 ph,, e ACopom q..,n.sa. 50 f.. Ian# =a an@ son. A qv,lcfi@ A, Ily-ilb- (At, top.l., slylop".1. 4.6ophl/h.. Hh.,- sp", Mcn,,Aord (encrust.) A ACfA00r0 formoso, wifirporo (ramose) ISLAND REEF, TELUK DJAKARTA (BAY OF BATAVIA) LOW ISLETS, AUSTRALIA Based on UnIq-e.1939.1947 Based 0. Mant.., 1935 0 S?O IOW Net Fig. 15. Cross sections of windward Pacific reefs not showing development of algal buttress. Note differences in size, geomorphology, and coral species zonation. (Wells, 1954). d a A 389 SHO E REEF FLAT ALGAL RIDGE SEAWARD SLOPE I a, i,. Idler A. to I.,.- Nleop... Zone Ac-polo I.r. A@ tyipilifera C- Se,;OfopV and Wrote" 101.0,Y) rone son Zone SI),1000ro obvn arl) 'a Zone BIKINI, MARSHALL ISLANDS L.Pfos"'. ,an* so De.9frophy he sone, r SHORE RIDGE SHORE REEF FLAT BOULDER ALGAL REEF FLAT ALGAL- 1b.al @hctnntrl) RIDGE ........ . . . . . N,hVPO,V on. 'Pall" A ....... ------- 10 1-- ---, .1 A A P-1 P", Z... P-10 Algal - It 'a to-Ir Buttrwrisits AUA REEF, PAGO PAGO HARBOR, TUTUILA, SAMOA ISLANDS ROTUMA ISLAND to 40 fat h..S Based on Mayor, 1924 Based On Gardiner, 1890 D E SHORE BOULDER ALGAL SHORE ALGAL REEF FLAT ZONE RIDGE REEF FLAT Ri DGE 0, posido,io se-f.p.,O on. pall" P_j, 1 -2 11.1 Vr r ,on* ran' to, bela. Fawt, on, twh..) 1*11 rare Zone of co,ols) MAER ISLAND, TORRES STRAIT FUNAFUTI Based On Mayor, 1918 Based 0. Gardiner, 1898 F ALGAL P LATFORlA L.. lifs, ".0 ACrop- Ivmi a Zone Gentle slope for 3-4 .,1,. A"Opo'. 10 1othoms; unstud.to JOHNSTON ISLAND G REEF SHORE F LAY ALGAL RIDGE lo@ z,* 1-01 b.".. -to TAGELIB, ARNO ATOLL, MARSHALL ISLANDS IT ir Flits Fig. 16. Cross sections of windward Pacific reefs showing development of algal buttress zone as in Fig. 5. (Wells, i954). I\NDS S 36,65 S M-05-1 S 36.84 C. 414 414 C 36.78 S 36.80 C 4!7 S 1 ..20 Ci. 46.i' S 36.11 Ca 410 14 4 rA 412 3 .35 S 3 .76 36 CA 3539 402, 1014 PLAN KI Bach k"Zz OM 0.. lmp&ex limst-. thick- MkWW Tedwy and I ftmestones@ mtK and CA 364 C, 35, 406 calewma ".d.W_S ';@ awai.. Sslb*y, in Pts par "Misaw wata, . S to- C"A"M Fig. 17. Distribution of beachrock, coral reefs, and limestone in Puerto Rico. Coral colonies that do not reach the tide level are not shown, although several offshore reefs exist. Note reduction of coral reefs on wave stressed north shore. (Kaye, 1959). A.) 391 Gonodactylus oerstedii Bohinometra luounter Mithrax soulptus. 4-65@Holothuria parvula Petroliethes galathinus -3160phiothrl angulata mploria labyrinthiformig, Porites porites Gorgonia flabellum Peaudopterogorgia americana Montastrea annularis Panulirus argus Fig. 18. Conceptual presentation of two common reef community types in Puerto Rico. Large branching coral species in upper diagram is Porites furcata, in lower diagram, Acropora palmata. (Glynn, 1964). 392 Table 1. Oxygen metabolism measurements on Puerto Rican coral reefs and adjacent environments (Odum et alog 1959)- C)Nygell Nietabolisto 4 ;lranw/rn2) in I I If! Wa It! rs of SOH thweslern Put-a-to Hico Wcn= ne[ daytime Community plintolyll I flesi.@ I wr I iown ;I I.= Ili gl it time to viratinity respiration per hour: Pg= tie I p hot ospithesi.9 per (lay WWI. night .14 added; R7,i = 24 hour community respiration hawd on night V. C,.,,,,,l T-1, WiAA u,,d I,A.@ pl. rast. La Cata Reef, Fel 1. 27 1310 AF 1.75 ...... ...... Por-*tes reef 0 if) 7.6 27.5 1959 1335 AF 2.8 La Gata. Thalassia lied 7.3 27.5 ch. 27 1100 AF 2.8 .... .... 1958 Lit Gitta Ret-f. Parifes anti Thalassia 0.3 Slight 25 -28 Fvb. 18 24 IRC I.V+ 1.8+ 8.6+ 11,3+ 195H lirs. We@t La Gata Reef, Thalassia 0.26 6A '24-28 Feb. 28 1160 AV 2.6 1958 Margarita Heef, Porite!; varpet 0.23 0-9 2S- 28 Felt. 25 24 A 1.4 0.5. 4 44 1958 lirs. Isla .1ilapit-yes. swulliern shore, Poriles and Thalassin 0.3 0-3 25,21, Feb. 17 21 BC 0.32-1- 0.75+ 121- 18+ I hr%. La Nle,lia Lima, Afillepilia, Not; Acropora and Nriict; 65in 0.28-1 5-11 28-30 Joile 12 24 AC 20 1.21 38.4+- 207+ 1949 lirg. Lwi Palntaq, Thalgvia 0.3 1.1.1 2.5-28 Fri.. 2" 3 1237 A F 1.33 958 nnrtli (if Isia Magiteyc@, Thaht@siri 1.2-4.5 4.2 26-29 F-A-. 13 24 lJ(; 0.50 0.52 10.5 12.5 1958 11 I.S. --- 2i--28 Mar. 1 24 11C, 0.60 OAS 11.0 12.5 I QSR 11 rs. Enrique Reel, Alillepora Thahusia Zoanthus, Dietyota, Porites 0.1-0.6 6.4 27 -29 Mar. 12 24 A 2.0 0.1)"" 20.0 17.3 19.58 lirs. El Marie, Reef 0.39 4-8 May 29 24 AF 1.6 1.5 39 36 1959 lirs. Huhia Fosforescente, ,rwai iiny 4 Jan. 24 24 B 0.08 0.2'e 5.6 7.7 1957 lirs. Planklon only Jail. 24 24 1) 0.06 0,09 1.4 2.3 19S7 lirs. (Table 2) Tifulassitl lied .... Fell. 12 24 BC t),85+ 0.75+ 15+ ]a+ 1958 lars. Thalassitt lied Mar. 13 2.1 11C ... - 5+ 6+ 19-58 lirs. Total Bay 4 .... 3',Tar. 13 24 See <48 <48 i 95H Ims. t"I C RS 7.7 Planklon only 4 .... Julle 1 24 1) -0.18 0.29 1.4 6.9 1959 111-8. A. it. I at-.1 tt"-iniif. w,,r -d-j C. Suatt. I],- i. -nit, adntWi.i., tol ..1- Wl- ihi, @14-o 6 nini.-I 11. Dark 4-1 light bwii-@ E. 0m. - . N I.U, ji-i.d diff-i.n --oion UpSTREAM EL MARIO, MAY 29, 1959 ENTERING SALINITY 32 %. LIGHTS ON CIGHTS OFF LIGHTS ON LIGHTS OFF REEF 0 + + OYSTER POND CORAL (MILLEPORA) 0 2, 0.10 O.to DOWNSTREAM STATION mg/l ........... 6 12 18 P-39GM/V/0AY 2 OjO OJO RATE g./m2Ar. 7 1'3 19 1 a 6 1..2 18 6 0 0 LIGHTS ON LIGHTS OFF LIGHTS ON LIGHTS OFF + + 36 GM/M2/DAY CORAL X tPORITES) 00 OSAM (2N ISIPM 00 CORAL 2 TIME OF DAY 0.10 (PORITES) 0.10 Fig. 19. Diurnal productivity measurements on.a Puerto Rican coral reef, measured as change in dissolved oxygen of reef waters. Production during daytime (P) almost. . ...... .. . equals night-time consumption (R). (Odum et.al., t959). ::X 0.10 0.10 _A 6 12 Is 24 6 TIME 6 12 is 24 6 Diurnal rates of carbon dioxide uptake and release during net photosynthesis and night- time respiration in an oyster pond microcosm and in three small, Ziated coral heads. Fig. 20. Productivity measurements on indIvidual reef corals by measurement of carbon dioxide. The corals consume more C02 than they produce due - , W'. 01' to metabolic requirements -of sAbiotic algae. (Be@yers 1963) %10 394 Florida and Nearby Reefs Fringing the curve from Miami southwestward to Key West and several miles to the east of the Key West Highway lies a barrier reef. East of it, in the Florida Strait, flows the Gulf stream (Figs. 21, 22,23). Further to the east lie the Bahama Banks with their numerous islands and extensive reef flats. The Florida reef tract extends some 200 miles ending in a few small reef islands,;the Marquesas Keys and the Dry Tortugas. The lagoonal,waters to the west of the Florida reef alternate with islands having occasional patch reefs. The first 30 miles of coral reefs from Key Largo south are preserved as the John Pennekamp State Park. The Marquesas Keys are.a National Wildlife Refuge, while the Dry Tortugas are preserved as a National Monument. Like most Atlattic coral reefs, the Florida tract is mainly several feet below the water surface at low tide, contrasting with Pacific reefs which are generally at the surface at lowest tides. This could be explained by a recent rise in sea level with coral growth being inadequate to keep pace with the rising waters although conclusive evidence is not available. The lower nutrient levels of the Atlantic Ocean as compared to the Pacific may be a contributing factor (Sverdrup @@t al-, 1942). Fig. 2A depicts a poorly developed reef occurring toward the northward limits of reef formation in Florida. Graded changes occur in a southerly direction as conditions for reef formation improve. The well developed reef described by Goreau (1959) and depicted in,Fig. X shows characteristic Atlantic reef structure. Storr (196ba)studying reefs in the Bahamas at Abaco Island across from Florida listed the following zonation from shcre to deep water: urchins and encrusting algae, Porites corals, Acropora corals, Alcyonarian corals (sea fans),.and massive Montastrea coralls-C-Fig. 24). Fig. 25 gives a cross sectional diagram of the Florida reef tract and shows the distribution of different types of calcareous sediments, mainly derived from skeletons in the several reef zones. Individual reef corals from the Florida Keys studied by Kanwisher and Wainwright (1967) had high ratios of net photosynthesis to dark respiration, as listed in Table 2. Their results showed that the zooxanthellae photo- synthesizing within the coral tissues cause the corals to be among the most productive organisms in the world. Table 3 is a study of metabolism in free water and measured with bottles filled with water from near reefs at the northern ext emity of the Florida tract (Fig. 22). The mean of 3.6 g dry matter per @@ per day is much lower than-values found for more'highly developed reef areas. Considerable destruction of reefs occurs with hurricanes (Shinn, 1963)- Eniwetok and Bikini Atolls Much wokk has been done on the biology and geology of Pacific reefs, particularly in conjunction with nuclear weapons testing carried out on Eniwetok and Bikini Atolls. These reefs axe some of the best developed and most diverse ,of marine communities, trhere structural and functional adaptations reach utmost complexity. Figs. 5-,,6,9., and 26, 27 illustrate reef morphology (Emery et LI., 1954; Ladd et al. 1950; Tracey et al., 1948). 395 BOW n 4 ....... .. . . . . .. .. AZORIDA BAY VO -5 100 PI-ORMA AS',rRA-17' 2e& A map of the Florida Key region. Land is shown in black, and the shallow inshore water (less than 3 fAthoms deep) in'white. Following this, the water between 3 and 10 fathoms is closely dotted, after which Ikedeeper water (10-100 fathoms and over 100 fathoms) is again white, but the 100-fathorn lirle is indicated. Fig. 21. General view of Florida reef tract. The Dry Tortugas and Marquesas Keys lie farther westward, and are not shown. (Stephenson and Stephenson, 1950). A." 2 VAT -0- % Aiv Ir OR i,\ A) A- Y XO, o MAJOR ENVIRONMENTS OF SOUTH FLORIDA L E 0 E N 0 REEF TRACT A, re -ONS OF STAT6ORS LOCIT CAL .-C '0. 111- c s.81 C, All., -CaG5 C-11 IZ49, IZ50 .00 ej Fig. 22. Coastal features at the southern tip of Florida, showing reef distribution.on the Florida tract. Reefs as in Fig. 24 occur at northern end @of the tract, with structural- I complexity increasing southward. (Ginsburgtt al.,19.63)@ 397 A 2' b 4nY -4 'AA, Z" 25' WKE ZONE k* E Rlock diagram of Key Largo Dry Rocks showing ecologic zones and major t% pes of .1 cropora palmala growth f(@rins. Fig. 23. Generalized diagram of reef morphology on Florida tract. Groove and spur system is in evidence, although not as well developed as on Jamaican or Paciftc reefs. (Shinn, 1963). TETRACIITA A- ECMIN6METRA PORITES CORALLINE@ THMASSIA AICYONARIA ZONE$ ALCYONARIA THAIASSIA PORITES-CORALLINE ECHINOMETRA MMW 0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - MLW rV44 F 2 3 R E E F F L A T IOWER ;UPPER P L A T F 0 R M 5 A diagrammatic transcct seaward from the tipper platform to a depth of 4 feet below mean low water (not drawn to scale). The slanting lines represent the solid rocky base, the stippled lines represent calcareous sands and mud. The horizontal broken line represents the. level of mean low water sprin.-s, The horizontal distance shown is about 300 feet. Fig. 24. A less well developed Florida reef occurring toward the northern limits for reef forma tion. (Voss and Voss, 1955.), t7 l'11--il. 4i@ 398 SE REEF TRACT CARD SOUND NW OUTER CORAL KNOLLS MUD BANK Mainiand REEF ARC IBACK REEF FINE - GRAIIIN ED. CARBONAT A 'N ZZ.- ............ 'V -ff 1 M 0 LU S Figure 25. The upper portion of diagram shows cross section of the Florida reef tract. The distribution of sedimentary types is presented, showing the relative amounts of each type of calcareous sediment in the various environments. Fine grained carbonates may arise by chemical or bacterial precipitation from seawater. Halimeda is a common green alga with a free standing thallus made of calcified blade-shaped "leaves"; at death, the "leaves" crumble to form a fine calcareous sediment. Foraminifera are individual microscopic organisms (Protozoa) which produce tiny calcareous skeletons, each of which becomes a "sand grain" upon death of the animal. (Earley 1967, modified after Ginsburg, 1956). @@-_G @@' I N E 0=ARBONATE 399 Table 2. Productivity measurements on individual corals by oxygen measurement. The corals show ability to produce 1.9 to 5.8 times more oxygen than they consume.' (Kanwisher and Wainwright, 1967). Calculated values of gross photosynthesis per unit surface area, maximum observed ratios of photosynthesislrespiration, and observed or estimated photosynthetic compensation light intensitiesfor some Florida reef corals Maximum Compensation light Species Gross Photosynthesis photosynthesis intensity in Q. C/ml./day respiration tootcandles Gorgonacea Plexavra flexuosa 6.5 5.8 400 Gorgonia ventalina 6.8 3.0 300 Briareum asbestinum 3.7 2.5 400 Erythropodium caribaeoruin S.8 4.2 600 Scleractinia Siderastrea siderea 4.0 2.1 300 Poriles divaricala 10.2 3A 600 Faviafragum 4.2 2.3 400 Manicina areclata 5.2 2.4 - Montastrea annularis 9.5 2.9 200 Oculina diffusa 8.4 S.0 - Dichocoenia stokesii 8.0 - 300 Mussa angulosa 2.7 1.9 300 Isophyllia multiflcra 7.9 5.0 400 Colpophyllia sp. 5.4 3.2 700 Table 3. Productivity measurements performed in the vicinity of reefs at the northern end of the Florida tract. (Jones.196-,T). PRODUCTIVITY VALUES OBTAINED FROm LIGHT-DARK BOTTLE EXPERIMENTS AND NET OXYGEN GAIN IN WATER BETWEEN 0600 AND 1200 DAILY - 1961 1962 Aug. Nov. Mar. May Gross, Bottle Experimenis: Oxygen Gain (ml/L/day) 0.06 0.78 0.04 0.06 Carbon Fixed (mg/L/day) 0.03 0,42 0.02 0.03 (g/M2/day) 0.06 0.84 0.04 0.06 Ret, Bottle Experitnents. Oxygen Gain (ml/L,/day) 0.02 0.52 0.04 0.00 Carbon Fixed (mg/L/day) 0.01 0.28 0.02 0.00 (g/ml/day) 0.02 0.56 0.04 0.00 Wet Change in A ni bient Water: Oxygen Gain (ml/L/day) 1.84 0.88 0.78 1.66 Carbon Fixed (mg/L/day) 0.99 0.47 0.42 0.89 (g/ml/day) 1.97 0.94 0.84 1.78 PROFESSIONAL PAPER. 260 tj V Z.-Z -A-C ? '41% A4 IVEL --- SEA U (29.5*- 27 G 7S t) _q) ar 10 fathoms 0 r- @Ilb - : : @j 0 0 Acroporo m : 'a reficulato -1b tj Q. r- Ckqlo subzone QL Echinophyllio 0 - - - - - - zone MICROATOLL L- - - 10-FATHOM LAGOON; !FATHOM :ALGAL: SEA 50fathoms LAGOON REEF REEF FLAT :TER (27.5*- 26' C) TERRACE RIDGE RACE: --------- Leofoserts 01 zone ISLAND SEAWARD REEF SEAWARD SLOPE --- 80 fathoms - - - - - - - 7 (24.5*- 2 2' C -Sclerhelio - 0, Den hyllla zone VertiCGI exoggerotion X5 rooo Tooo 8o6o 90,00 10..'00 1 1'@00 12.@oo 13,0100 14, 00 15,00o Feet 0 4.5*- 12% ZONAL ANALYSIS OF CORAL FAUNA AT BIKINI ATOLL 293438 0 - 54 (In packet) No. Z Fig. 26. Cross sectional view of the windward edge of Bikini Atoll, Marshall Islands. Coral Knolls can be seen in the lagoon region. (Wells, 1954). _Uz 4 -- 15,1A L.@VEI r (29.5 27 Ampolo 0 160 30' 401 z 11'401 nuclear 1 J: test V. sites NORTH PACIFIC OCEAN LAGOON 4 outer reef ef buttress inner rei dropoff Rigili 1. 0 Z! Japtan reef:--- Japtan 1. N- Deep pass Wide pass Eniwetok I. active reef nautical miles Fig. 27. Eniwetok Atoll, Marshall Islands. This is a circular atoll with about 40 islets, lagoon of max, depth 200 ft., and two major passes through the reef. Knoll reefs dot the lagoon. Islets are in black, and reef areas stippled are awash at low tide. (DiSalvo modification of Hines, 1962). 0 402 Estimates of biomass of animals on quadrats are given by Odum and Wum 1955) for Japtan reef, Eniwetok (Fig. 28). The unidirectional flow of water over the reef allowed determination of changes in cominity structure and water quality at successive stations across the reef from upstream to downstream (Figs. 29 and 30 and Tables 4 and 5). Estimates of metabolism from oxygen curves in Fig. 29 are given by Helfrich and Townsley(1965) In Table 6. Reef nutrition through removal of dissolved materials from sea- water was hypothesized by Doty (3-958)', and laboratory evidence favors this assumption. Examples illustrated are the work of Yonge (1931) who showed that Australian corals could remove phosphorus from seawater (Fig. 8) and Kawaguti (1953) who showed that corals removed a=onium. compounds (Fig- 7)- In unpublished tracer experiments DiSalvo found that hermatypic corals could remove certain div&lent cations from sea water. Stevens (1962) similarly found corals removing dissolved organic substances. The reef may be with- drawing and recapturing substances from its overlying waters as ,indicated in Fig. 29 for Eniwetok. Some particulate matter is exported to the lagoon (Fig. 29, Table 4, and Marshall, 1968 and Johannes 1967)- Highly relevant are studies tracing pathways taken by radionuclides released into oceanic waters during nuclear testing. many reports (See bibliography in Hines 1962) have demonstrated high radioactivity uptake in reef corals collected at Eniwetok and Bikini including rare earth elements. Effects of these nuclides .on the coral tissues are not known, although atypical growths resembling calcareous tumors have been described for a few corals recovered from bomb test areas (Hines, 1962). Rapid decay of radioactive and specific di .fferences are indicated by data such as those in Fig- 31. The reefs are highly@specialized for retention and recycling of materials, and studies on detrital release by reefs at Eniwetok and elsewhere have not shown as yet that significant quantities or organic matter are released from the reef (Johannes, i967; Marshall, 1968).' Hiatt and Strasburg (ig6o) Wesent the food web of a coral reef in Fig. 32. They show feeding relationships of reef fishes (Figs- 33-35) which control passage of fission products through complex reef food chains., (Fig. 31). So little was known gbout the functional biology of the coral reef ecosystem prior to nuclear weapons testing that the after-effects of this disturbance remain obscure. Reef areas near test sites* are undergoing recolonization by corals and other invertebrates, although large areas are covered by atypically occurring filamentous algae (persoml*observation, Di salvo, 1964). Physical damage done by the bombs approximated the damge that might be expect6d from a typhoon (Wiens, 1962) except in the immediate vicinity of the blast'where reefs were destroyed by direct shock and radiation. Residual turbidity affects recovery* A milder type of reef disturbance has been observed by Brock et al. (1966) at Johnston Atoll, to the east of the ''MEwshall islands. At this military base the creation of new land from reef areas by dredging (Fig. 54) has resulted in the siltation of widespread reef areas with concomitant change in the envir- onment. A new system may be developing as evidenced by changed'structure, diminished diversity* of animals, and increased population of the substrate by atypical species of filamentous algae. Some of these chapges are outlined in Tables 12 and 13. 403 QUADRAT ANNELib.s -P-C R As S 1 CORALI -C RUSTACEA POLYPS 1-4-URCHINS FLESHY UStf AGCAREOU@ A ALGAE IN CORALS I ENCR N ALGA R-ANNELIDS, ETC* @[email protected]( ONES CORAL -F'TL NNELIDS P OLYPS-F --A IR4CHINODERMS AL AE 0,LGAEJ I N B IIN dO FLESHYENCRUSTING@BORING ALGAE NES STARFISH ISH CORAL POLYPS ANNELIDS CUCUMBERS URCHINS,ETC. FISH c 1ALGAEL[-ALGAE ALGAE ALGAE INI LIN CORA IN S MINGLE IN REEF FLOOR IDEADHEADSJ RABS MOLLUSK ism C.ORAL I;WECHINODERMS MOLLUSKS,ETC. 1POLYPS FISH ALGAE ALGAE ALGAE "SEAWEED" JF;j-ALr3AE kN D JINCORAJIN SHINGLEIIN- DEADHEADS ICLUMPS I SAND SH VF'I S H E-F E ALGAE IN 1ALGAE IN SHINGLI SAND C I I grms. 11-1- 132g;g MEAN PRODUCERS - 7 0-3 grms, H/P 18.9% C H - 8.3 0/6 0 @200 460 600 Soo DRY BIOMASS IN GRAMS PER SO. METER @irntnids of biomass resulting from estimates of the dry weight of living materials (excluding, of course, dead skeletal materials associated with protoplasm). For eacii quadr at, A-F, the weight of "producers" (bottom layer of pyramid), the "herbivores" (H) (middle layer), and the ,,carnivores" (C) (top layer) is shown,neid almo tht- avernge dry bioninas for the reef. Fig. 28. Estimates 6f'biomass in six distinct zones found across the Japtan reef, (Fig. 27), Eniwetok Atoll. Zone "A" was located on the reef flat behind the buttress zone, "B", "C11 i 11DII were zones of successively larger coral heads'across 'the reef, and zones "E-F" were lagoonward sandy back reef areas. (Odum and Odum, 1955). I S 4H IISF, 12oo- A -1200 OCrAN A B (L U t 1000- -1000 50.- Loss ON IGIVIrION 800- 800 -"C1,3 0 JAPTAN 600- 27 JULY -600 28 JULY 10L 400- 11 -400 40. - -7. PLANr RONGELAP A E 200- -200 0-- IWG IM3 01@_KAPAA (NOV.) SAND -200- -200 4. 1/0S RADIOAC71VIT?' -400- .400 COUNTS /'W'V. 0400 0800 1200 1600 2000 2400 0400 0800 .1200 1600 2000 2400 TIME TIME Production and consumption,of organic matter. A, North Kapaa Reef, 27 July 1956 and contont as it crosscs the 28 July 1956. B, North Kapaa Reef, 25 November 1955; reef at Japtin Island. Eniwetok Atoll; and ,reef ill re-ard to: less Oil i'll'16011 of not plankton nnd reef at Rokujarito island, Rongelap Atoll. Data not corrected for diffusion. Data from Japtan and sestoll; greoll plillit colitel't (estiniate.1 by clilorop'1711 Rokujarito are from Odum and-Odum (1955) and Sargent and Austin (1954), respectively. content) of net 1)1:liiktoji; suspended sand; radioactivity. Fig. 29. Changes.in water over Japtan, reef, Eniwetok. (Odum and Fig. 30. Diurnal curves obtained:in coral reef studies, showing that Odum,'1955). total organic productiop only slightly-exceeds consumption on the reefs studied. Results are derived from oxygen - measurements made on reef waters. (Kohn and Helfrich,. 1957). G I\LS-5 ON / @Glv r, _AA N a AP A- A13 I RADIOAC71V17-K C U V -f3 @AA 405 Table 4. Organic inputs and outputs over Table 5. Chemical levels in Eniwetok the Japtan reef. (Odum and Odum, waters. (Odurn and Odum, 1955). 1955). Balance sheet for tile jaiptall intor-islan4l rompo'writ Analyses Mean lta'!ge reef in Jui 'V. rrow algal-coral ridge to tile cild of tile zoiic of large livalls, this zone is 322 rn2 loug. Orpnic %fatt,r, alk-line ivrnangante method. in mg/l ....... ........................... 13 .9G .74--l . ;l gal/ral/day Nitrate nitrogen. strychnidine method. in mg . - I stol.18/111.1 ................................ 24 .44 A:- 1 '41 i Inorganic phmphorus, a 111111AIlium n1olybdAte ]PIRIlk-t0niC organic matter (Table 1:1) frorn I methad in ing atmns,'inl ................... 29 .32 .2r- .0+ Total pbosphorus, aciii digested, in n,g breaker Yone . . . . . . . . . . . . . . . . . . . . . . . . - + Primary production (ineasured as ONygen, atoins/ml ............................ 6 1.7 3@1 calculated as glucose: Dissolved oxygen, Wiijkler method, in ingy 1. Not (uncorrected) dayt 14.0 11) Incoming Ocean Water (froal cha-cl).. 3 6.51 6." .8 10.0 Itc8piration during da) time ..... (2) Algal-coral Ridge ..................... 12 0.50 6.00--G..N - (3) Itack Reef zone of Large Ile"i Total income .................. 26.0 Daytime ............................. 19 7.31 6.22-8.30 Night, @ .............................. 6 3.37 4.89-6.21 LossF.s* pH (Deckntan Model C.) Planktonic orgalric matter lost to lagr on Daytime (Tal)lc 13) . ; .................... .... 0.4: Incominz Ocean Water (from channel). 5 S.21 S. I Total respiration in 24 hr ........... .... 24.0 A!'@d-roml ridZe ........... 3 S.21 S. I L-5-1 I 13ack Reef zone of large heads .......... 3 8.32 Total out 0 ................... )474 Night Incoming Ocean Water (from channel). 2 8.19 S.18-8.10 Alpl-coral ridge ..................... 2 8.18 *Dissalved Organic Matter; 0.", grn/ml (Table 14) (no siguificant ditrem.re Back Reef Zone of large heads ........ 2 8.10 8.10-S.10 between influx and outflu%; analytical metho4 not precise CHOUgh, b we'rer, to delimit.) Temperature in degrees Fahrenheit :The mean water flux during p!ankton samphig was 425n0/hr across"a band of reef 1 m wide. Incoming ocean water (from channel) .... 2 SZ. 6 82.6-42.7 Algal.caral ridge ....................... 2 $2.9 82.7-K3.0 Back reef zone of large heads Daytime ........................... 3 84.1 93.5--81.6 Nighttime .......................... 1 82.2 ....... Table 6. Summarized results of coral reef productivity measure- ments compared to similar measurements performed in other marine environments. (Helfrich and Townsley, 1965). GROSS PRO- DUCTIVrry GRAMS CARBON/ LADcATioN ms/XEAR ReFERsNcr. roral Reefs El Mario Reef, Puerto Rico ......... 7,117' Odurn, Burkholder, and Rivero (1959) Eniwetok Atoll, Marshall Islands. 4,200' Odurn and Odurn (1955) N. Kapaa Reef, Kauai, Hawaii.... 2,900 Kohn and Helfrich (1957) Rongelap Atoll, Marshall Islands. 1,800' Sargent and Austin (1954) Turtle Grass Beds Long Key, Florida ......................... 4,650 Odum (1956) Redfish Bay, Port Aransas, Texas 2,080 Odurn and Hoskin (1958) Open Ocean Benguela Current .......................... 167-912 Steernann Nielsen (1954) Sargasso Sea. ....... :: ....................... 167 Riley, Stornmel, and Bumpus (1949) Off Hawaii ..................................... 37 Steernann Nielsen (1954) Off Rongelap Atoll, MarshaU Islands ........................................ 28 Sargent and Austin (1954) Off Hawaii ..................................... 21' Doty and Oguri (1956) =of I I determinations. diffusion correction applied to published data. AveraSe of deterdkinations from stations I and 2. lopoo 406 9POO spoo 7,000 r"Poo - 5,000 4,000- 3,000- XE-% " GU PAR OT 2.000- FISH IPO 900 Soo- UL-I 700- 1 A CORAL SAND 600- 500 " 1 400- -%-U3T.' C/M DAM;E 300. FISH zoo XE-11 GIJ@ SURGEON Soo- FISH 90 so 70 60 50. 40- 30-. XE- 40 OVARY, DAMSEL 20 FISH XE-37 'D XE-19 LIVER, OYSTER DAM L FISH 10 too 200 300 400 500 600 700 Soo 900 948 1949- DAYS -1950 Fig. 31. Decline in radioactivity of fishes and sand collected over a two year period after nuclear weapons testing at Eniwetok Atoll. (Donaldson 1960). 407 1 "25 TROPHIG LEVEL .3 5A Ll S.011 arge id..Gttr zooplanklon Plankto feeders carnivores .......... Tm=@ ii, Phytoplankt n or", s 'o. 14, odors Transient Pholosy Detritus Ornnivor*s TIOM.0 nth*$4 Large benthic 081ritus carnivores feeders Boothia 019 Algo Smot bent it an n1vor 8 Fig..32. A hypothetical food web,to describe the complex trophic(feeding) relationships on a coral reef. Constructed from data obtained in a comprehensive study of Marshall Island fishes. Trophic levels 1-5 represent primary producers, herbivores, and three levels of carnivore, respectively. (Hiatt and Strasburg 1960). BAr_K RsoGiE Taour." 0 C04ALOW: RtOGE V Fig. @33. A conceptual diagram of.reef structure and fish fauna of the surge channel and surf zone of a Marshall Island reef. Fishes are shown in characteristic feeding attitudes. (Hiatt and Strasburg, 1960). 409 0-= ......I c-l- '. ki. SuP 4@) O(c J@ ";@@ tm' (a) 41 0:'-. A.-t 4-r- .01.0 (b) Fig. 34. (a) Fishes associated with branching corals as noted for Marshall Island reefs (b) Herbivorous-fish in characteristic feeding attudes as seen on Marshall Island reefs. (Hiatt and Strasburg, 1960). Al v'r W-4.0 "A@ for t '.." (...t VW_ nd% t.0 , aw 40 0:: th T Lat@ Fig. 35. The mid-water surface-community as found near coral reefs of the Marshall Islands. (Hiatt-and 0 Strasburg, 1960). Wfiereas the aforementioned studies of ocean-lagoon water flow across Japtan reef (Odum and Odum, 1955) concerned an inter-island reef at Eniwetok, there are similarities between it and the fringing reef of Bikini Atoll where water washed onto the reef returns to the ocean by percolating down through tunnels in the buttress"honeycomb" area (Figs. 26, 36). Hawaiian Coral Reefs; Kaneohe Bay., Oahu The Hawaiian Islands (Fig- 37) axe a showcase demonstrating geological emergence and subsidence-with concomitant formation of coral reefs. Fringing reefs (Figs. 38 and 39) axe found around the coasts of the younger islands, where incipient reef formation has been studied (Daty,1967c; Oostdam 1963). The northernmost islands of the Hawaiian chain axe the atolls of Midway and Kure. Rock corings at Midway (Fig. 10; Ladd et al; 1967) showed the presence of reef limestone and shallow water fossils to a depth ofover 1000 ft. capping parent volcanic basalt. This depositionwas estimated.to have taken over 30 million years. Fig. 29 and Table 6 from Helfrich and Townsley(1965) show the reefs in Hawaii to be in the se productivity class as the Pacific atoll reefs. The steady pattern of life histories and larval release was established by Edmondson and Ingram (1939) (Fig. 40). Although the temperature shift is only a few degrees between seasons, a pulse in reproductive activity was re- gistered, with apparent favoring of the su r'season of greater light for productivity* Brock (1954) has provided relative species and biomass estimates for fishes of several Hawaiian reefs (Fig. 41). Some quantitative biomass estimates for leeward Oahu reefs (Fujimi a, i-96o) axe presented in Fig. 42. Distribution patterns and niche substitution in carnivorous cones were studied by Kohn (Figw. 43). A wealth of taxonomic and descriptive information has been published about the fauna of Hawaiian reefs, including reviews of fishes (Gosline and Brock, 1960), sponges (De Laubenfels, 1950), didemnid ascidians (Eldredge, 1965), snapping shrimp (Banner, 1953) molluscs (Tinker, 19>6) and others (see Edmondson, 1946b). Kaneohe Bay, Oahu (Figs. 37 and 44) is the site of the University of Hawaii Ybxine Laboratory and is also the site of intensive study on the in- fluence of stress on an environmentally diverse tropical bay. The extensive development of reefs in Kaneohe Bay is attributed to the presence of a Hawaiian barrier reef (@bberly and Chamberlain 1964; Fig. 45)- This reef extends almost the entire length of the bay, providing a nataral breakwater while allowing a constant overflow of clean waters in a wind and tide-driven circulation (Fig. 46) similar to that described for atolls Von Arx, 1954 Bathen 1968). This bay'has been receiving heavy flows of sewage at its southern end, causing high phosphate values as depicted in Fig. 24!7. Freshwater inflows in addition to sewage inputs produce salinity changes and increases in turbidity as illustrated in Figs. 48, 49 and Tables 7, 8- The changing pattern of the system includes development of plankton-base char- acteristics (Peterson, M'Thesis, Dept. of Oceanography, University of Hawaii, 1968) effects on shoreside clam beds (Higgins,NS Thesis, Dept. of Oceanography,, University of Hawaii, 1968) and development of bluegreen algae-worm-oyster reefs (DiSaivo,'personal observations). The development of the oyster, Ostrea gigas on seawalls at Coconut Island in Kaneohe Bay was noted by A. J. hn. to have Occurred since 1954 (personal conmmnication). Some of these effects axe undoubtedly related to the coral'reef freshwater kill of 1965 (Figs- 50 412 Sea @ tress and surge channel zone (000 C nnels and bl 0* rho e s partly -L-@ Hoheycomb area Outer HeliqMra zone Reef flat old reef flat Reef flat -Lone j4eliO Island Fig. 36. Oceanic reef zonation at Bikini Atoll. See also figures 16 and 26. (Emery, Tracey and Ladd, 1954). 13uttr too PO e'aal 413 S 1W KAUNAKAKAI ICAHULUI USR 5 WAILUA SW FS W Kauat HW USR WN IW S'N1016kaj USR S Maid HW NAWILIWILI S W TU R 1W 14ANA -I _HWj S Oahu US R Lanai., 1W R 5/" 1W 'W S HANAPEPE II, S SW 1W 5W C.-J, XAFAAUM W USR H ... HW KAHUKU USR 1W I W 4P HW WAIMAI HILO R USR KAILUA Hawaii HW 0 S SW S m U WAIALUA S m W %% I W S W SW USR S XANLOHE U5R 14W S KAILUA WALANAI U EU@SR PEARL HARTO't S LEGEND HONOLULU HARBOR SW-SEWAGE DIAMOND MW-MILITARY WASTE SW HEAD I W -INDUSTRIAL WASTE mw HW-HARBOR WASTE BAISERS PT. MW HW USR USR IUSR-uReAN sToRm WATER RU OFF 1W USR S S S -SOIL I W 1SWon occasion I S_ Fig. 37. Pollutional influence around the Hawaiian Islands with particular reference to the Island of Oahu. (Knaefler, 1967). 414 FINIBRISTYLIS PYCNOCEPHALA RHIZOCLONtM HOOKERI ITTORMES @,ENTOPHYSAJUS DEUSTA CALOTHRIX CONFERVICOLA- ----ANACYSTIS AHMFELTIA Cocos a CaSAURINA +loom - CHLC!jOCCUM LITTORNES -POOOSCYPHE r NES (AY@ +020111. Do--- -030 m - GELIOIUM 0 0-- CRUST OF CORALL INE ALGAE Pm 25M ALGAL STU1381 E a P ATCHY CORALLINES POCILOPORA + AL L TCHES THIN CGOARALPLAINE PATCHES LITTORINES IER Lly@ ly, --305101 --0'0 LOW TIDE LEVEL 2M @@AOTTOM NKEWLAYE@'@ 3m Fig. 38. Differences between an established shoreline and a shoreline affected by recent lava flows. This diagram represents early colonization of volcanic rock by algae (see Fig. 39) which precedes the development of a coral reef. The upper section of the diagram depicts a mature shore near Hilo, Island of Hawaii. The lower part represents shoreline affected by the new lava flows on Hawaii in 1955. (Doty, 1967 c). 4t5 A B C D E F G H I i K LITTORINES BLUE GRLCNG - - - - - - - - LITTORINES BLUE GREENS - - - - - - - LITTORINES LITTORINES LITTORINES LITTORIMES NERITA BARREN fFINE - - - - - - - -LBROWN - - - - - - - - - - - - - - - ECTOCARPUS LIMPETS LIMPE tS LIMPETS LIMPETS ECTOCARPUS WHITE+SPOTS FINE ECTOCARPUS LIMPETS LIMPETS I GREENS I NTF ROMORPHA ECTOCARPUS ECTOCARPLIS ECTOCARPUS RALFSIA ECTOCAR" ECTOCARPUS + PALE TO CHNOOSPCRA WH2TE CORALLINE CORALLINES SPOTS ENT RO@ PINK ;NE- -J MO-HA CHNOOSPORA CHNOOSPORA WHITE CMNOOSPORA CIOMSPORA CHNOOSPORA INE CHNOOq" CHNOOSPORA CORALL S EN]- A + LIMPETS A PO YOPES POLYOPFS HNOO" OR POLYOPES CTOC= '; W;i;' + COR ALG LIAGORA POLYOPES ef:@ 11AGOIjA RED TURF '-spotse. -i- P'W %Y114UL GRLENS ALMOST F-;;P S CORALLINES DARK RED TURF INARREN RED TURF POLYOPES DARK TURF RARREN + LIAGORA eUT FOR PINK LIMPETS CORALLINES CORALLINES RED TURF RED TURF LIMPETS ISM OARK PINKER TURF RFD TURF 4 CRUSTOSE RED TURIF A FEW CORALLINES PINK SEPARATE IEIRDWN CORALLINES CORALLINES TURF Population changes in time on a vertical xg5s lava surface extruded into the sea and observed as fiAlows: A & C at Kaucleau (respectively), 2i-Vl-xgSS and i5-Vl1l-:Eq55; and at Kehena (respectively). B, .110-XII-1958; D, 2I-XII-1955; E, 24-111-1956; F, 16-V-1956; G, 14-VIT-i956; H, x8-VM-i956; I, IoLXI-1956;j, 20-[V-1957; K, 3o-XU-i958. The base line for measurement was the top of the particular polmlation across which on the figure a dark horizontal line is drawn. This corresponded in general with a set of recognizable physical features of the shore but the physical features changed from time to time as Cro-lon took place. Fig. 39. Algal colonization of a recent lava flOW.in Hawaii. (Doty 1967c). MID PACIFIC OCEAN 416 so- 25 oc *F 20 TEMPERATURE 70- ,A(A NE 0 HE A MP H I P 0 0 S C A M P A N U L A R /0 A E PENNARIA TIARELLA 8 U G UL A NERITINA SCHIZOPORELLA UNICORNIS COMPO UND TUNICA rr s HKDROIDES NORVEGICA OSTREA rHA ANUMI 8 A L A N U 5 AMPHITRITE F M A I M I J J I A S 0 N___l D Kaneohe Bay, Oahu, Hawaiian Islands. Fouling of various ma. Hydrograpbic Office. World Atlas of Sea Surface Temperatures (13). For addi- terials on short and long term exposure. After Edmondson and Ingram (6). tional information on fouling in Hawaiian sea, sm Visscher (41). Temperatures: mean monthly sea surface temperatures in Hawaiian region, from Fig. 40. Fouling in Hawaii. Months other than Jan. and Feb. are favored for larval release by fouling organisms. (Woods Hole Oceanographic Inst., 1952). Abb4 %.,*A pt K.A%.k.. W 5-1d. L@q. S-11 Uftod, A-f%-d, P P ...O.d. Species composition by estimated weights of fishes observed along transects in nine localities around the islands of Hawaii and Oahu. Each vertical division represents 100 pounds. Fig. 41. Quantities Of fish per standard transect over Hawaiian ID + jr coral reefs. Quantities of fish are related to complexity of the bottom structure. (Brock, 1954). Yards 1000 0 5' - - - - - - 10 Fathom Line OAHU Yo],,c hama Beach Maile Ksaau Station D Station C Station B Station Shaded section.= 258.3 Shaded section la,-3.-acres Shaddd-section 309.9,acres Shaded s Lbs.. of fish/acre = 28.7 Lbs. of fish/acre = 35-.4 Lbs. of f ish/acre = 57.9 Lbs. of Fig. 42. Standing fish,crop in pounds per acre of four fishing areas along the lee coast of Oahu. incipient reef development. (Fujimura,'1960). C. SPONSALIS 4- 2- A@ C. ABBREVIATUS 6- 4- 2 C.EBRAEUS 6- 4- 2- C. CHALDAEUS 3- 2- I 3- C. RATTUS 2- I 3 C.CATUS 2 SUB AERIALI SLOPE WATER LEVELED BENCH __@@IPART Fig. 43. The species of Conus inhabiting a wave-cut littoral bench in Hawaii, with the distribution of individuals along a transect from the landward to the seaward edge. (Hutchinson, 1965;after Kohn, 1959). swor z QQ :r 0 le 0 0) m 0 0 0) 1." m CL CL :3 0 ri) 0 :3 :3 to ol rt m m CL rt 0) rt OrQ =1 (5-9 m m n & o 0 :r 0) 0 1-4 91 m :r I-h m El rt M 0 :r pi rt 9: m rt 1-0 0) 14 rt 0 :r I-h @-h 03 @4 rt q 0 :3 m 1-3 =1 . W m H v m ct M :j 0) 0) OQ '4 W. 0 pi n w- OQ m C) m 1.0 OQ 0 pi i;51 00 m 0 Fl- 0- m :j m m "IN (1) IT I-h 0 %4 H. n 0 n 0 N pi 03 rt 0 m P1 A) 0 m SID m H 1-h 0 OQ @_A m M 14m A4 H0 m:r rtm CL ozt 157*50'W 46* 421 BASIC CURRENT PATTERNS INCOMING TIDE KEY; 0-3 METERS 3-7 METERS ............. ..-> 7METERS WIND$ 0101-070, 3 - 13 KT& TIDAL RATES:6-Ill CM/ MR. 30' C, i:.) -7 od .. 41 V 21* 21* 2V 25' N 157@50' 46 Fig.@46. Basic current patterns in Kaneohe Bay during an incoming tide. Wind, wave, and tide driven currents come across the barrier reef, causing deep outward moving currents at the north end of the bay. (Bathen, 1968). C. 064 06S D 0. 0.2 0.5 0.3 a 0.4 0.5 KEAAHALA STREAM 5 ocLs 0-7 <a 1@ 6 0.3 ts W 13 (31-0 KANEOHE STREAM '0.2 ID SURFACE PH-CSPHATE (rWcro gm atrm/L) Ma*rch 4. 1967 Fig. 47. The southeast basin of Kaneohe Bay which receives sewage outfalls. Typical phosphate (reactive phosphorus) distribution on the surface on March 4, 1967. (Bathen, 1968). % M.11, 1967 SALINITY A FOLLOWING MOD. HEAVY RAIN PERIOD OXeSERVATION 34-50 PERIOD 2 hr. % 34.30 Ohl TIDAL CYCLE % 34.00 1 33.70 KANEOHE STREAM I KEAAHALA S 32.50 33.50 0_9 .61%10 @REAM M3/day) \ 33.00 F Is. 11, 1067 --*131.00. 32.00 14 0 2.5 A r/ 7-01 MAR 4.1967 @2-P @4 FOLLOW NG LOW RAIN PER Rio C D OBSERVATION PERIOD 0 IV. 31.00 TIDAL CYCLE 12 hr 20.00 30, KE AAHALA STREAM KAN EOHE S 0.30 10 - 2.81 Is 104 10.00 MAR. 4. 1967 SAL Fig. 48. Southeast basin, Kaneohe Bay. Stream outflow and salinity (surface). ISO shown for Feb. 11, 1967 (solid) and Mar. 4, 1967 (dotted).- (Batben, 1968) 424 Table 7. Water transparency in Ka Bay (secchi disc) from Aug. 1963 to July 1964. neohe (Piyankarnchana, 1965). bV IV C.Otcop Extinction Coefficient Montjj Line I Line !I Line III August 0.327 0.369 0.3G9 C-L-4kP Septemiber 0.252 0 . 2 1.1,3 O.S00 October 0.26G 0.293 O.SG7 10 @ArFALL November O.3G9 0.293 0.395 Decer,iber 0.215 0.224 0.266 January 0.395 0.39S 0.708 rebruary 0. 2 54 0.266 0.347 March 0.254 0.309 0.42S j1pril 0.3&9 0,.425 0. L@72 Y, ay 0. Lt2 S 0.500 0.630 June 0.266 0 ' .34.7 0.630 JU1.v 0.395 0.500. 0.809 Fig. 49. Locator map, Kaneohe Bay SE basin, for Tables 7 and 8. (modified from Piyankarnchana, 1965;and Gundersen and Stroupe, 1967). Table 8. Transparency (secchi disc) and pH values for Kaneohe Bay waters. Stations 2-4 on locator map, 5 is in middle sector of the bay, and I and 6 are oceanic stations outside the bay. (Gunder'sen and Stroupe, 1967). STATIC14 pH TRANSPARENCY (M) EXTINCTION ,A'Z= AVERAGE PANIGE AVERAGE COEFFICIENT 8.1 6.0-0.5 11.5 7.6 2 SLRFACE 7.9 3.0-7.0 4.7 0.36 SOTTC.M 7.0-8.1 7.6 3 SURFACE 7.9- 8.1 8.0 2.0-3.5 2.5 0.43 C3TTr,i .7.4-8.2 7.9 4 SJRFACE 8.1-3.1 8.1 4.5-5.5 5.2 0.33 60TTU-1 8.1-8.1 8.1 5 Sl'")FACE 8.1-3.2 8.2 8.0-10.5 8.8 0.19 Sl@ -ITCV. 8.0-8.1 $.1 6 S -:11 ITAC E 8. 1-3. 2 8.2 12.5-18.0 15.3 E,,5TTC@4 8.0-3.2 8.1 425 and 51) as discussed below in the section on stress. The influence 6f man cannot be denied, however, with increasing inputs of poorly treated sewage wastes and increasingly diffuse and silt-laden freshwater,runoff due to suburban construction. Fig. 37 illustrates the extent of pollution on Oahu as vis- ualized by newspaper reporter Tomi Knaefler (1967). Clutter (1968) found phytoplankton and zooplankton concentrations higher in the corner of the bay receiving vasteso Bermuda Lying 600 miles off the coast of North Carolina in the Gulf Stream, the island of Bermuda and its surrounding reefs (Fig- 52) represents the northernmost extension of coral reefs. Bermuda is structured somewhat like a Pacific Atoll in that its reefs enclose a shallow central lagpon.' The reef fauna include hardy Caribbean varieties, and many species are maintained by larval importation on varm. Gulf Stream currents. Several studies of importance.to the understanding of reefs have been carried out at Bermuda. Fig. 52 (inse't) shows the @mall reef surveyed by Bardach (1959) for fish population. He found 490 kg. of fish per hectare (49 g/m2) of which 30-40% was cited as being replacement growth. Re:presen- tative data are given in Table 9. Pigo 53 from.Neumarm's (1966) study in Bermuda illustrates the importance of boring (clionid) sponges in the break- down of limestone coastlines. This regeneration process is important on all reefs of the world in maintaining the balance of calcium and carbonate ions in seawater. DISCI)SSION Reef Structure and Zonation Reefs generally consist of a porous lim6stone framework gradually filled with calcareous reef sediments and cemented together by encrusting cal- careous organismso Lower regions of the reef are ultimately consolidated into a solid basement limestone by processes known as diagenesis, as yet poorly defined. Goreau (1961) emphasizes the fact that maximum accretioii of calcareous matter occurs near the turbulent surface waters where mechanical. and chemical erosion processes are paradoxically at a maximum., Variously o:@ig@nating com- ponents have evolved a coherent structure adapted for maximum. attenuation of wave stress, yet exposing Maximirn surface areas for biological functioning. The skeletons of coral colonies produce the primary reef framewokk (Goreau, 1963)- @bst coral,colonies consist of hundreds of tiny polyps interconnected by a thin sheet of tissue. The polyps continuously reproduce asexually at the colony surface causing expansive growth by secreting their skeletal cups of aragonitic limestoneo Separate colonies may interlock by contiguous growth or may be cemented into larger framework units by encrusting coralline algae. Spaces within smaller framework units, as well as large 426 >( Od /Y 4't@ I-N V lu@-- 00 AN 0 I;D --0.5 Z.0 al go FA IS7*51W Fig. 50. Kaneohe Bay, Oahu, Hawaii. Lines represent "isonekros" given by.Banner (urpub.) to indicate depths in meters in which corals werekilled during May 1965 catastrophe. (A.H.Banner,Univ.of Rawaii,unpub-ms-) 427 Coincident heavy rains and reef kill,,, 1965 1.7- 1.6- 1.5- 1.4- 1.3- L2 S.E. BASIN 0 SURFACE M 1.0 gr S.E. BASIN Z T rAL 01 7 h@ 1% 1@. I., ., .6. '00-c%k SAY TOTAL A - .3 - .2 !Pop 0 A S 0 N D F M A M MONTH Fig. 51. Reactive Phosphorus in Microgm atms/1 Bay Total, Southeast Basin Total$ and Southeast Basin surface. "Total" curves are-the mean values for the entire water column and the "surface" curve is for the top meter of water. -Bathen, 1968). 9P 428 N 50' Cao Afap of one-hectare study reef. The 0 dotted areas represent sandholes. 0 0 C, C 0 0 96 NAUTICAL MILE 00 CPO CO 0 0 00 0 0 Q@ 0 A) 0 A 0 0 0,3 0 0 C 2 C--) 0 0 JU--) 0 0 .0 0 Q00 Q0 32* 15'N 64-' 45'W Map of Bermuda islands and surrounding reefs. A. Location of one bectare study reef. R. Location of study area on extended reef surface. Fig. 52., Bermuda and surrounding reefs. The structure of Bermuda -- suggests comparison with Pacific atolls, with its' ring of reefs surrounding a relatively shallow central "lagoon". (Bardach,1959)- 429 Table 9. Standing crop of fishes on a one-hectare reef in Burmuda as illustrated in Fig. 52 (From Bardach 1959). Numbers of individuals t@aad their estimated total weigh .kg) - Av. wL Fishes' 1955 1956 1957 kLfba Wt. No. WL No. Wt. Omnivores (mostly herbivorous) Angelfish Holacanthus bermuden8is 82 20.5 47 11.8 45 11.3 14.5 @ (250) Surgeonfish Acanihurus sp. 150 30.8 27 5.4 18 3.6 13.3 (200) Parrotfishes Adult Scarus and Sparisoma sp. 46 46.0 46 46.0 50 50.0 47.3 (1000) Subtotals, omnivores' 97.3 63.2 64.9 Juvenile Scarus and Sparisoma 70 24.5 24.5 (350) Mise. small fish Young surgeon and parrotfish pomacentrids, etc. 7000 70.0 4200 42.0 56.0 (10) Total weight, omnivores 155.6 Carnivores Red hind Epinephelus gulialus 63 37.8 24 14.4 42 25.2 25.8 (60b) Nassau grouper Epfneplielus striatus 9 10.0 9 10.0 12 13.4 11.3 (1115) Otber groupers Mycferoperca sp. 12 18.0 10 15.0 12 IS.0 16.0 (1500) Coney Cephalopholis fulvuz 15 6.0 3 1.2 3 1.2 2.9 (400) Grey snapper Lu1jantis griseua 82 82.0 78 78.0 81 SLO SO.3 (1000) Bluestriped grunt Hacmulon sciurus 226 90.4 353 141.2 2.50 100.0 110.5 (400) Porgy Calantw sp. 3 2.3 1 0.8 6 4.5 2.5 (750) Puddingwife Halichocres radiatus 4 1.2 2 0.6 1 0.3 0.7 (300) Spanish hogfish Bodianus rufus 24 4.8 15 3.0 25 5.0 4.3 (200) Hogfish Lachnolaimus maximus 6 18.0 3 9.0 2 6.0 1110 (3000) Subtotals, carnivores' 270.5 273.2 254.6 Subtotals, omnivores and carnivores' 367.8 336.4 318.5 Moray Gyninothorax sp. 24 9.6 - - 9.6 (400) ,Small wrasses Thalassoina bifasciatuin and Halichoeres sp. 3200 32.0 4000 40.0 - - WO (10) 430 Table 9 (continued) Numbers of individuals (and their estimated total Fishes' weight, in kg) - Av. wt. -No. 1955 Wt. -go. 1956 wt No. 1957 WL kg/ha fishes yolocentruS sp., Apogon sp. Blenniidae etc. 1200 24.0 24.0 (20) Total weight carnivores 334.8 q,,nd total weight 490.4 1 Figures in brackets under species names give average individual weights of fish in grams. I Subtotals of omnivore or carnivore species respectively for which three separate Counts were ,mide. I Subtotals of all species for which three separate counts were made. Occurrence of certain species of reef fishes on an extended reef near Bermuda, summer 1957, as counted by two divers, 317 and B Date of Count Fishes June 14 June 20 June 26 July 16 - Au 19 Sept. 6 )II B M B M B M B Omnivores Parrotfisbes Scaru8 9 9 13 15 23 23 29 35 47 39 Sparisoma 9 6 27 12 33 19 28 20 27 22 Angelfish Holacanthuz 14 is 14 14 is 19 25 20 Surgeon fish Acanthuru8 11 4 30 21 20 14 21 18 33 28 Carnivores Red Hind Epinephelus 1 2 2 1 1 gutiatuB Groupers Mycieroperca sp. 1 - I - I Coney Cephalopholis - - 2 - - 5 1 1 3 2 fUIvU8 Grunts Haemulon sp. 3 3 1 2 4 2 5 5 2 4 = rs egriseus 3 - - 1 - - - - - - Puddingwife Hatichoeres 2 - 2 2 2 2 3 - - radiatuB Others - - 9 7 5 4 3 3 3 9 (Barracuda) (School of jacks, 50+, seen by both) 431 SUBAERIAL ZONE LITHOLOGY PITTED SPRAY BEACHROCK REEFROCK SURFACE ZONE EOLIANITE INTERSTITIAL MARINE LMS. ALGAE WAVE SMOOTH -.0 SURFACE ZONE..10, ROWSERS GASTROPODS CHITONS ECHINOIDS CRABS INTERTID7AL FISH BORERS ZONE JLU ALGAE BARNACLES ECHINOIDS /ENCRUSTERS MOLLUSCS ALGAE , - BRYOZOANS WORMS WORMS SPONGES CORALS MOLLUSC LOW HIGH ENERGY ENERGY Illustration of the general coastalL morphology and zonation observed at Bermuda including notation of biological agents and processes associated with coastal erosion. Fig. 53. Coastal erosion in Bermuda. Sand formation and the return of calcium and carbonate ions to seawater are accomplished by macro-and microscopic processes of limestone breakdown. (Neumann, 1966). ES I S ID CS S 432 areas sequestered from the force of waves are gradually filled by transported calcareous fragments ranging in size from sands to gigantic storm-tossed boulders. Although there are several overall dif ferences in plant and animal species composition between Atlantic and Pacific coral reefs (Wells, 1.957), reefs exposed to similar wave energies show similar geomorphological zonation. Fig. 1 depicts the general morphology of a Jamican reef which has similarities to other Caribbean reefs but is among the best developed with regard to com- plexity of zonation and species of coral. Some of the,zones in Figs. I and 36 may be described as follows. The inshore reef flats are inhabited by physiologically hardy varieties of animals and plants which can withstand stresses caused by temperature and salinity fluctuations. The channel, or lagoon region is a sandy back reef zone seen in various forms on many of the world's coral reefs. These are usually quiet waters which receive calcareous sediments produced on other regions of the reef. An active foraminiferan population may produce sand. As mentioned above, in areas of high temperature and slight water movement calcium carbonate may be directly precipitated from seawater. Turtlegrass beds commonly found on Atlantic reefs are less common on the Indo-Pacific reefs, and are usually replaced in those regions by calcareous algae such as Halimeda. Back-reef coral zones are typically very diverse, in the absence of limiting stress , and are usually chosen for popular magazine articles as representative of coral reefs. Where lagoons exist, deeper lagoonward zones may show luxuriant coral growth with corals expressing their most typical growth forms. Large formations in these areas are often interspersed with reef sands. Large fish populations are often seen grazing in these areas. Shallower coral flats, exposed or nearly so at low tide, are populated by species of low spreading corals or adaptive forms of species also found in deeper waters. These exposed flats often become decadent areas when upward growth and low tide combine to cause fatal exposures to air and sunlight. Sedimentation on these sites makes them amenable to colonization by coconut palms or mangroves with eventual island formation under favorable conditions. The buttress zone is a region of the reef which grows outwaxd against the forces of the ocean. Coral growth forms show protective orientation with respect to waves, and selection is for the sturdy species. Inverte- brates living in these regions are usually small and well adapted for holding onto the substratum. As the buttress system gives way to deeper waters more fragile corals appear, and coral growth gradually thins out as light becomes limiting@ Sediments broken from the reef front are either washed over the reef into the back reef zones or deposited down the,front face of the reef as a "talus slope". 433 The major difference between fully wave-exposed reefs in the Indo- Pacific and those in the Atlantic is the absence in the latter of-a calcareous @lgal ridge breaking surface water at low spring tides (Yongeo 1963a). This algal ridge is,formed primarily by the Melobesioid algae (eg. Porolitho ) and small coral heads. Fig- 5 shows the algal ridge and buttress zone at Bikini Atoll in the Marshall Islands. This is a form typical of Pacific reefs and is related to similar structure (Fig. 23) on' the Florida reef trac@ imaica (Fig. 1),and some other wave stressed reef -areas. The.coral species c4stri- bution in relation to depth has been given in Figs. 6 and 26. Variations in reef morphology are seen as one travels toward the extremes of the temperature regimes of reefs. Fig. 94 shows a more simp2y structured reef occurring near Miami., Florida. Figs. 15 and 16 demonstrate variations in reef morphblogy in various localities. Trophic Organizatibn The living units of reefs are arranged in a highly adaptive manner for maximun.efficiency of food production,food acquisition,food consumption,and cycling of waste products. Fig.1 illustrates 6oifie faunal segments and reef representatives. The primary producers on reefs are the ubiquitous reef algae.These algae include the encrusting and f:@ee-standing reds (Rhodophyceae),the fila- mentous and free standing green.6(Chl6rophyceae),the benthic diatoms @Bacill- ariophyce@e'),boring and encrusting bluegreen algae(Cyanophyceae),and multi- tudes of 6ndosymbiotic algae(Dinophyceae),inhabiting the tissues of corals and some oth6r'invertebrates. Marsh (1968) found U& primary productivity of Porolithon(a red encrusting alga,Fig@4) and Bakus (1967, )has shown high production rates for potential@Ly nitrogen-fixing bluegreens (Cal6thrix Schizothrix) growing on the Eniwetok reef flat behind the algal ridge. GrMing, rasping, and boring animals e-L-vut: une surfaces of hard sub- strates and chew up calcareous materials, absorbing digestible products and Passing out residual matter as fecal detritus. These animals include sea urchinsy crabs, errant polychaetes, toring molluscs and worms, and grazing gastropods and fishes. A large perceritage of the reef animals are adapted for suspension feeding, having adaptations for precipitation of particulateand dissolved nutrient matter from seawater. These animals include the sponges., solitary and colonial tunicates, sedentary po:Lychaete worms, barnacles, bivalve mblluscs, ceftain crustaceans, and echinoderms. Another segment of the coral reef population is adapted for moving throughout the dead coral spaces and scavenging detrital materials with re-ingestion and re-deposition of fecal pellets@ This group includes the errant polychaetes., gastropods., crabs and other crustaceans, and small fishes. Some predators on the above system include carnivorous gastropods,-starfishes, polyclad flatworms, errant poly- chaetes, and predatory fishes. The internal spaces of the reef frame are lined with a detrital sediment containing extensive bacterial populations (DiSalvo, in prep. The diverse microfauna in this sediment includes nannoflagellates, diatoms, protozoa,, nematodes, microcrustacea. and other micro-organisms suggesting active mineralization processes associated with complex micro-community- structure (johannes; 1965, 1968). Due to the complexity of reef biotic structure, the trophic relationships are not well documented. Hiatt and Strasburg (1960) show the ecological relationships of the fish fauna on reefs at Bikini, Arno, and Eniwetok Atolls in conjunction with nuclear testing (Fig 32 -35) 434 Processes Production measurements on coral reefs based on diurnal fluctuations (Figs. 19 and 30 and Tables 1, 3 and 6) are comparable to rates measured for productive agriculture (Odum,, 1959)1@although the community structure on the reef is such that the plant production is rapidly utilized in community main- tenance. A census and measurement of biomass on the Japtan reefj, Enimet,ok Atoll yielded biomass pyramids depicted in Fig. 28. Growth and accretion rates have been measured on coral reefs by several investigators. Mayer (1924) reported that the integrated vertical growth of a Samoan reef was 8 mm. (1/3 in.) a year. Edmondqon,(1929) found that corals on Waikiki reef., Oahu., Hawaii grew upwards at an average rate of 13 mm. (1/2 in.) annually. Oostda-m (1963) studying a reef on Maui, Hawaii., estimated the annual average production of CaCO 3 in the area to be ab out 0-32 1b. per square foot of which roughly ha@f was reef frame and the other half sediment (preceding three citations from Moberly and'Chamberlain, 1964). Rates of calcification for individual organisms are given by Goreau (1961) in Tables 10 and 11. Sandy sediments are derived from skeletal remains of calcareous algae., foraminifera, sponges, echinoderms., molluscs, arthropods., and other calcareous reef organisms. Daily activities of reef borers and scrapers result in the release of sedimentary particles from primary reef frame structures. Bardach (1-961) estimated that rasping fishes re-deposited lo8 g. of Caco per m2 'per year. The calcareous sediments of a reef can often be identified as to organismic@ origin and physical environment by inspection of microscopic characteristic6, ctnd are used in studying the paleoecology of reefs (Ginsburg,et al.,1563).Fig. 25 illustrates the recent distributional pattern of calcareous sediments on the Fiorida reef tract. Hoskin (1962) showed role of large animals in grinding skeletons. Stress The reef ecosystem, with its high rate of organic production and consumption and its many specialized oigahisms and organismic interrelation- ships is analogous to some terrestrial'climax ecosystems*such as tropical rain forests. The existence of great complexity and va,@iability suggests in some ways the division of labor and specialization of modern human cities. The state of knowledge regarding coral reefs is developed mainly along lines of taxonomy and physiology of the component parts rather than on functioning of the system as a whole. There are as yet few measured parameters which allow us to predict the nature of reef survival,, succession, @Lnd ability to sustain harvesting. As with other highly structured natural ca=mities (or cities) a disorganizing influence applied to a vital community structure or function may'prove disastrous to the entire system,, the ruins of which may emerge as a new system of altered structure with changed esthetic and eco- nomic values. Coral reef stress may be defined as any abnormal occurrence which results in the breakdown of reef structure and function. This may occur directly by physical., chemical or biological alteration of the reef., or indirectly by alteration of limiting factors as presented in Fig. It. The stresses easiest to understand are the direct physical destructions imposed on reef structure. Alteration-of limiting factors include-Rchange in 435 Table 10. Specific calcification and productivity rates of reef building (hermatypic) and non reef building (ahermatypic) organisms in Jamaica. Data obtained by measurement of concomitant uptake of Ca45 and C14. Specific uptake meas Iurements relate amount of uptake to the N content of organisms studied., (Goreau, 1561). Light Category Species or ig.Ca/nig.N/hr ALaxarborat- ,g.organic- Dark C/rng.N/hr. C/miz.N/hr. Ahennatypie S. rosew Tig-h-t 12.0 3.30 1.250 Coelenterata dark 13.2 2.46 0,489 without A. solitaria light 8.7 1.33 0.547 Zooxanthellae dark 8.6 0.77 0.400 T. tenuilamellosa light 5.5 0.56 0.217 dark 5.6 0.85 0.161 Herniatypic light 126.3 17.93 12.09Q Coelenterata (apical cm.) dark 1 35.1 4.09 0.861 with M. cornplanata light 59.6 10.19 A.680 Zooxanthellae dark 25.0 6.44 1.640 P. furcata light 26.7 8.14 13.800 dark 5.6 0.63 0.532 Hermatypic H. tuna light 178.0 23.211 !E6--.390 Algae dark 77.9 9.36 0.905 H. opuntia light 256.1 38.46 50.520 dark 72.6 11-82 0.899 A. fragilissima light 68.3 43.33 56.320 dark 792.6 87.24 2.180 Table 11 Calcification and carbon fixation rates of hermatypic and ahermatypic organisms on a daily basis. (Goreau, 1961). Calcium deposition Carbon Exation Category Species in jAg./rng.N/dav inug/mg.N/day Aherma pie Cocleniterata S. roseus -292.4 without z0oxanthellae A. wlitaria T. tenuilaniellosa 133.2 ffermatypic -Coelenterata A. cervicornis 1936.8 145.08 with zooxanthellae (apical cm.) I M. complanata 1015.2 236-16 P. turcata 387.6 165.60 i-i@r-typiv -algae H. tuna 3070.8 316.70 H. opuntia 3944.4 606.24 1A. fragilissirna 10330.8 1 675.84- 436 the temperature regime, salinity changes, and decrease in light penetration (turbidity) with-its concomitant physically damaging sedimentation. Reduction in water circulation and wave action may also have effects. The most diffi- cult stress to understand is the spontaneous appearance of a naturally occur- ring biological fluctuation. Physical Documentations of natural physical damage due to high wind and waves are numerous. Glynn et al. (1964) noted up to 50% demolition of reef corals on a Puerto Rican reef after the passage of hurricane Edith in 1963. Stoddart (1962) described extremely violent hurricane conditions which completely destroyed a Caribbean cay including its groove and buttress system. Wide- spread damage to corals of up to 800L was recorded for some tracts. Man-induced damage has been documented by Brock et al. (1966) who discussed the effects of dredging at Johnston Atoll (Fig-Ure 54 and Tables 12 and 13). Physical damage induced by human beings, including the removal of coral souvenirs, molluscan shells, and fishes (by spearfishing) in Oahu's Hanauma Bay prompted the Hawaii legislature to convert the area into a state natural preservation area. Temperature Naturally occurring mass mortalities of reef organisms have occurred as a result of their exposure to high temperatures and to air in shallow reef pools and areas exposed at extremely low tides (Mayer, 1914; Glynn, 1968). Although documentations of the catastrophes have been made, no data on long- term effects have been recorded. There are no records of man-induced reef disturbance due to temperature stress, although proposed construction,of a nuclear power plant at a site on northern Kaneohe Bay, Oahu, Hawaii may affect the normal temperature regime of coral reefs in the Bay in a region less troubled by sewage and land runoff V. Brock, personal communication). Salinity and Turbidity Coral reefs most likely to be affected by catastrophe are those near high land masses which promote heavy rainfall. During periods of rainfall, freshwater inflows (perhaps laden w-Ith silt or other detritus) may cause osmotic stress to corals and other reef organisms resulting in mass mortali- ties. Secondary effects of the runoff are siltation and eutrophication. Siltation affects plants and sedentary animals who may not be able to clean their surfaces efficiently for continued functioning, whereas eutrophication is an enrichment effect, promoting "blooms" of microorganisms which cloud the water for days after the rainfall. These effects may be duplicated or magnified by man's introduction of municipal primary treated sewage effluents. Banner (unpublished ms) describes the widespread reef "kill" in Kaneohe Bay, Oahu, Hawaii of May 1965 when unusual rains of nearly 18 inches fell in 25 hours, with a total rainfall of 30 inches in a ten day period. JOHNSTON ISLAND AND REEF 2 164V 12 "o 03 .08 13 Johnston Atoll showing dredged areas and the extent of silt laden water. *4,.. - o Legend: Black recently formed land areas. Cross hatch - areas of reef altered by recent dredging. Dots a reas of lagoon often covered by turbid water. Dense dots - area of lagoon and sea covered by very turbid water. Numbered dots - previous stations. Numbered arrows - new stations (transects) studied. Fig. 54. Johnston island and silted reef areas. See Tables 12 and 13. (Brock et al. 1966). Table 12. Changes in reef echinoderm fauna as a result of dredging operations. Number of organisms found along an arbitrarily established 20 meter transect line (Brock et@al 1966). A Comparison of the Echinoderm Fauna Inhabiting the New Stations Echinoderms Area 10 Area 11 Area 12 Area 13 Reef Dredged Reef Dredged Reef Dredged Reef Dredged area area area area Tripneustes gratilla x xxxx x xx Echinothrix diadema xxx Rchinothrix calamaris x x x x Diadema sp. x xxxx xx x x Heterocentrotus Mammillatus x Holothuria atra xxx Total No. Species 2 0 3 4 0 3 2 2 00 1964 1965 FISHES 41 species 20 species Table 13. Effects of dredging at Johnston atoll. Note reduction in percentage of living coral, B. Flora reduction of echinoderm faum, reduction in number of fish species, proliferation of 1. Algae collected from the top of a coral head ca., algae (Brock et al 1966). 1 meter below the surface of the water; water AREA 4 (Refer to map for location) turbid, visibility -- minus 2 meters. August 20, 1965. Material growing largely on dead Pocillo- A. Fauna pora. Greens Browns Reds Blue-Kreens 1. The dominant coral genera in the area: 1964 1965 Acetabularia Ectocarpus Antithamnion Calothrix Bryopsis PocockTe-lla @_e_ntroceras Lyngbya Pavona Same as 1964 Caulerpa CerAmiella Microcoleus Montipora Enteromorpha Ceramium. Gorfiolithon Acropora (vasiform) Griffithsia Acropora (cespitose) Herposiphonia Pocillopora Hydrolithon Hypnea The estimated percent of living coral: Jania Peyssonelia 1964 1965 Wurdemania 20% or less 1076 to 15% C. General Comments 2. The conspicuous echinoderms in the areal: This area, as in 1964, was still under the influ- ence of silt laden water (Chart 1). There was no 1964 apparent reduction in the fish population in.1964, but the recent count indicated a-sharp drop. This Heterocentrotus mammillatus .... XXX apparent drop may be biased considering the very Tripneustes gratilla ........... X high degree of turbidity during the observation period. The vasiform Acropora that remain in this 1965 area were often heavily invested with necrotic areas. Tripneustes gratilla ............ X (only 2 seen) \0 Most of the reef had a covering of blue-green algae and 0.5 to I mm of silt. 440 On days of maximum precipitation a 1.5 m deep freshwater lens covered the inner bay reefs, and the absence of winds prevented mixing of water masses. Sedentary or weakly motile organisms which could not avoid the fresh water were exterminated in great numbers. Hydrogen sulfide arising by decompo- sitional processes aided in the depletion of oxygen, and extensive inner bay reef communities were decimated (Fig. 50). In this reef kill the areas of greatest dieoff occurred toward the southern end of the bay which normally receives the highest freshwater inputs as well as municipal sewage inputs (Gundersen and Stroup, 1967). Measurements made three years after the catastrophe by DiSalvo (unpublished data) indicated increased N and terrestrial sediment content in dead coral formations nearer to shore, and a greater deple- tion of oxygen within spaces of nearshore dead coral formations. Another reef catastrophe caused by freshwater inflow was reported by Goreau (1964) for a Jamaican reef. A 17-inch rain occurred over a three day period on the fringe of hurricane Flora (1963) resulting in the wide- spread death of and physiological stress to corals which were subjected to salinities as low as 7 O/oo. The major indicator of physiological stress was the "bleaching" of coral colonies; that is, loss of their symbiotic zooxanthellae. As establish- ed by Yonge (1931), shading of hermatypic corals causes the zooxanthellae to be lost. This "bleaching" indicator is also prime evidence for man-induced disturbance on otherwise undisturbed coral reefs. Although the oil spill at Guanica, Puerto Rico has not been studied from the particular point of view of coral reef disturbance, Diaz-Pifferer (1962) has mentioned that corals in the area of the oil spill showed the bleached appearance. Many corals along the south coast of Puerto Rico west of Ponce are becoming white where petrochemical wastes are being released from industrial complexes. From delValle,(1968@- Cerame Vivas, et al.(1968); Austin and Austin (19681 and Ramos,(1968)there are suggestions tt@a-t industrial wastes on the south shores of Puerto Rico near Guayanilla and Tallaboa bays are receiving enough wastes to change turbidity and affect reefs. Bleached corals are numerous and there are suggestions that blue-green algae are increasing their coral boring activities as a result of the stresses. A grave threat to the reefs on the southern shores of Puerto Rico are the turbidity stresses induced by uncontrolled'waste discharges upstream. Restricted Circulation DiSalvo (unpublished data) has observed that when parts of the coral reef frame (dead coral head community) are removed from high wave energy zones and maintained under reduced conditions of water circulation, an internal anaerobiosis develops which causes the death of the internal aerobic community. Man-induced disturbances to reefs are also cited in the chapter on sugar mill vastes - which mentions the effects of these wastes on Hawaiian reefs. Mats of bagasse fiber accumulating on the reef surface reduced circulation and depleted oxygen, producing deteriorated conditions confirmed in the laboratory. 441 Stress of Biological Imbalance Predatory decimation of stony cor-als has been reported since 1965 over many miles,.ok Australia's Great Barrier Reef due to a population explosion of the poison s .pined starfish Acanthaster planci (Harding,1968). Chesher (1969 Science 165:@80-283) repo d extensive damage to the reefs of Guam,with reef kill (90%) as rapid as 1 km / month over 38 km of fringing reef 0The starfish feed on coral polyps, leaving behind the bare skeleton. The dead coral surfaces are then invaded by an atypical algal conmunity which aidsin causing-degradative effects on the reef framework., Normally occurring fishes leave the affected areas, seriously lowering the catches of reef fish.by islanders. In a 1969 survey report for the U.S6 Dept. of the Interior (through Westinghouse Research Labs, Pittsburgh,Pa.). Chesher indicated that numerous reefs of well known Pacific islands were being at@acked (Sai'pan,Tinian,Truk,Ponape,Palau, Majuro., and Arno). Although the starfish increase may be related to dredgirig,blasting,predator removal by shell c'ollectors, and pollutional influences such as insecticides, the ti-ue cause-effect relationship remains obscure. Conservation Practical and esthetic grounds encourage efforts for the conservation of coral reef areas, especially for recreation and study. Important advances have been made by the conservation of @t.John and Buck Island in the Virgin Islands., A great deal of fishing is usually done near coral reefs. Coral reefs are optimally designed natural breakwaters which influence the development and control of tropical coastlines.Part of this development includes the production and retention of calcareous sands which form tropical beaches, a major basis for tourism in Hawaii, Florida, Puerto Rico, and the Virgin Islands. Interference with normal reef growth and metabolism may alter sand formation and retention'and allow erosion and disappearance of the beaches. Chapter B-3 442 TROPICAL MARINE MEADOWS Howard T. Odum University of North Carolina Chapel Hill, 27514 Tropical meadows are beds of underwater grassy vegetation found in Rhallow, clear tropical waters. The.prineipal rooted plants in U. S. systems are broad-bladed turtle grass Thalassia testudinum; narrow bladed Diplanthera wrightii (Halodule); cylindrical manatee grass, Syringodlum filiforme (Cymodoce&); branching Ruppia maritima; leafy Halophila; and interdispersed bottom clumps of algae. The blades support small epiphytic organisms.' On the bottom among the blades of vegetation are many tropical animals of great diversity and beauty including urchinp4, sea cucumbers, tube worms, molluscs, and fishes, many afwhich burrow into holes in the bottom. The vegetation forms a heavy lay- er of matted stems that makes a firm carpet with the sediments, much of which consists of the skeletal fragments of the animals. Many of the animals live by eating the bottom material, extracting organic food from it and releasing the mineral matter which is often limestone white. The food chain starts with the photosynthesis of the bottom plant beds, followed by microbial decomposition in the old grass blades, consumption of the partially decomposed fragments by the bottom organisms, and their consumption in turn by the larger fishes. Many of the bottom ami Is are filter feeders that keep the waters clear while also processing the remains from the decomposition. Bacteria are abundant, partly decomposing the grass material into a soup which is then consv d by the bottom fauna. Distribution Tropical meadows occur in waters of moderate current energy 2 to 25 feet in depth in Puerto Rico, the Florida Keys, and South Texas. In zones of high wave energyespecially at the surface where waves break, the meadows are displaced by coral and algal reef systems. In,deeper and more quiet waters, the meadows apparently displace the coral system, being better adapted to use somewhat lesser light intensities and currents. The tropical meadow resembles somewhat,the temperate vegetation meadows covered in Chapter C-7A by Phillips, except that there arefewer stresses and less seasonal change . The populations adapt to a relatively minor pattern of seasonal cb%nW in insolation, temperature, and economy of food flows. Diversi- ties and specialization are better developed towards complex organization of ecological communities, less energy being involved in seasonal adaptations. Some members of the tropica-L meadows are fuuncL in suD- tropical zones such as North Florida (Strawn, 1961) ana South Texas, but the general pattern of complexity, variety, and white calcareous sediment tends to disappear outside of the tropical uniformity of climate. The turtlegrass 443 system in Texas is an example of the northern limit of the tropi,cal meadow where many temperate properties of seasonal pulse, variation, and change are imposed on species associations, which fluctuate less in more southern distributions. EXAMPLES High Diversity Meadows in Puerto Rico Turtle grass beds floor the shallow waters among patch reefs near La Parguera, Puerto Rico (seeFig.2in Chap. B-4). Studies at the University of Puerto Ric'O are cited in Figs. 1-4 and Tables 1-7. In Fig. 1'Glynn (1964) diagrams the scatter of larger animals in heavy beds that occur in several feet of clear, high salinity water. With very even' temperature regimes, these beds at 18'degrees N. Latitude receive only about 25% insolation differ- ences with season. Burkholder, Burkholder, and Rivero (1959) provide tables 1 and 2 on the weight of the beds(from 2.4 to'32'.9 tons per acre, the rhizomes underground'increasing in coarse sandl Gilberto Cintr6n in an unpublished report found 3.2 tons/acre in Fajardo in eastern Puerto Rico. Chemical analyses showed balanced concentrations of many amino atidsi 25% ash, and 13% protein. Around, on, and within the blades, large concentrations of bacteria were counted (Table 5). Margalef (1962) found the photosynthetic pigments most abundant some distance behind the tip of the Thalassia blade (Fig. 3). The tip is the oldest part and the ratio of chlorophyll aL to otherpigments absorbing in the violet was greatest with age, the tips becoming coated with attached and diversified algal epiphytes. Margalef uses the ratio as a measure of complexity. Chlorophyll also was large in some of the many algae dispersed among the blades (Table 7). The high productivity of the whole bed is shown in Fig. 2 where the.oxygen curves of water drifting over turtle grass are used to calculate gross photo- synthes:Ls(10.5-14 g/m2/day in February). Odum, McConnell and Abbott ('1958) found 0.43 g/m2 chlorophyll a in these beds,.a moderately high quantity. The various indices show prc@ductive utilization of the light and a complex community of animals and bacteria. Table 8 from Warmke and Almodovar (1963) shows small molluscs associated with particular algal species in small proportions, not overgrazing, suggesting programmatic organization of roles. Another example of -specific control is the antibiotic activity of the calcareous green alga Halimeda (Fig. 4). Meadows in the Bahamas Stable environments producing tropical mdadows with high diversity also occur beyond the Gulf stream over shallows of the Bahama banks as shown by Kornicker (1958) in Bimini sound (Fig. 5). Note the many species of associated algae and animals. The broad Bahama banks are lapgely covered with.bottom meadows,sometimes thin and sometimes thick in shallow waters. The cumulative actions of photosynthesis in the shallow waters lower the calcium and carbonates in the water (Fig. 6 and 7) because of the calcareous precipitation, mainly by organisms. The ratio of these elements to chloride@decreases over the banks. 444 a Y Y Y \Y Y @@Y Va 'micina areolata Diadem, antillarum Cerithium litterat= Lytechinus variegatus Strcmbue gigas dd@ Holothuria mexioana Fig. 1. Components of turtle grass in southwestern Puerto Rico from Glynn (1964). ISLA MAGUEYES FES 17,1958- PQRtTES Tanto por mil de Relaci6n 02 00.3 M x clorofila a D430/D665 MY L 5- LASSiA 1,45 2,42 2,38 2.2.6 02 3- THALASSIA 0,72 2,11 2- RATE + I ORITE ORRECTED MY L 0 Fig. 3. Chlorophyll and pigment absorption 4-.72 CIM/MYDAY ratios of a Thalassia blade in Puerto R718 GM/M/DAY Rico (Margai-ef, 1-962). W or. 12N ISPM C TIME OF DAY Fig. 2. Oxygen productivity data comparing coral reef and turtle grass in Puerto Rico (Odum, Burkholder, and Rivero, 1951). 445 -.-Manglares at Bahia Fosforescente Rocks, Lighthouse 6 -Margarita Reef 5 A ; IN.% V 4 % . 3 2 PC.- % % IA 0 JAN. FEB. FAR. APR. MAY JUNE jULY AU3. SEPT. OCT. NOV. DEC. The antibiotic activity of Halimeda.opixtia on Stapbylococcu aurtux in one year, with readings taken on the i and x 5 of each month. - Manglares at Bahia Fosforescente 6 - Rocks, Lighthousc Margarita Reef 5 4 3 2 0 50 .1=7= JAN. FEB. MAR. APR. MAY JLTNE JULY ALG. SEPr. OCT. NMI. DEC. The antibiotic activity of Halimeda opunfia on Eichericbia roli in one year with readings takenon the i and x 5 of each month. Fig. 4. Antibiotic activity of a calcareous green alga on bacteria (Almodovar, 1964a). "x" Tables 1-5- Stocks and chemical contents of turtle grass in southwestern Puerto Rico (Burkholder, Burkholder, and Rivero, 1959)- ABLE 1. Standing crops of whole Thallassia plants (leaves, rhizoines, roots) it, per acre. Location Tons per acre TABLE 4. 12nino acid constituents of the leaves of Thqlassia testu(jinum expressed West Las Palmas in per ce'nt (gin. amino acid per 100 gin. of dried material). For comparison, typic, East Las Palmas 12.1-18.3 data obtained for leaves of Spartina alterniflora are also given. Y,ast of La, Parguera 2.4- 3.1 Bahia Posforescente 3.7- 4.9 Thalassia Spartina La Cueva, West 5.8-25.7 Amino acids % of drv matter % of dry matter La Cueva, North 17.6-32.9 Arginine 0.7.02 0.182 Aspartic acid 1.120 no assay Glutamic acid 1.090 no aggaT Histidine 0.310 0.02ii Isoleucine 0.249 0.143 Leucine 0.693 0.214 io of roots and rhizomes to Lygine 0.720 0.769 TABLE 2. Influence of bottom sediments vpon the rat Methionine 0.187 0.038 .,-es in Thalassia. Phenylalanine 0.465 0.128 Threonine 0.204 0.256, Dry weight in grams Tryptophan 0.049 0.086 Location Roots and rhizomes Leaves RR Valine 0.317 0.149 (RR) (L) L Fine mud 38.5 12.8 3.0 East of La Parguera Mud and sand 378.5 79.7 4.7 West Las Palmas Coarse sand 336.5 46.3 7.3 TABLE 5. Quantitative estimates of the aerobic bacteria present in I-. -tivironmel. East Las Palmas of Thalassia at Magueyes Island, Piterto Rico. Bacteria per Source of Samples gm. of Sam, 1. Surface water outside Thalassia 627 2. Surface water above Thalassia 600 TABLE 3. Proximate analysis of Thalassin leaves, Porites, phytoplankton, Spartinw 3. Water in bed of Thalassia 3,968 leaves and Coastal Bermuda grass leaves. All data are given in per cent dry weight, 4. Witter from agitated Thalassia 192,000 except the calorie values. 5. Mud from bed of Thalassia 3,700,000 6. Thalassia ground in mortar 15,104,000 Materials Determinations Thalas8ia Porites Plankton Spartina Bermuda leaves coral L.I.S. leaves grnss Protein (N x 6.25) 13.1 3.4 14.6 9.8 13.1 Pat 0.5 1.4 3.7 2.4 on. 0 Ash 24.8 90.4 59.5 11.5 4.6 Crude fibre 16.4 1.5 1.6 31.0 33.0 Other carbohydrate 3-5 1.9 15.6 45.3 47.3 Calories/100 grams 1910 23 154 375 Table 6. Trace elements in turtle grass in Puerto Rico (Stevenson and Ufret, 1966). 447 Levels ot Fe, Un, and Ni in thalli and sterns ot P. gymnospora collected at Punta Higuero and T. t6studinum collected at La Parguera, Puerto Rico OAgIg dry wt) Fe Mn Ni P. gym- T. fes- P. gym- T. tes- P. gym- T. fes- nospora tudinum nospora tudinum nospora tudinum 5,700 210 150 44 28 17 4,700 310 85 36 23 19 4,100 290 84 53 32 23 5,600 270 120 54 28 22 4,000 93 80 72 27 19 4,400 450 89 47 24 24 520 140 91 36 26 15 X 4,100 250 99 49 27 20 s,1,733 120 25 12 3 3 Table 7. Chloropbyll and pigment ratios in green and brown algae in Puerto Rico (NbLrgalef, 1962). Tanto por mil Especie de clorofila a D430/D665 Penicillus capitatus 1.8 1,69 (cloroffcea) Halimeda opuntia 0,27* 1.81 (clorofrcea) Dictyota cervicornis 1. 2,52 (feoffcea) *Referido 1 peso seco.total, Halimeda contiene mucha caliza. 0 @A (D 0 Q@ 0 0 00 1.4 (D CL 00 tj Bryopsis 0 pennata 0 Fl- (4 lots), P P, C+ 0 Cauterpa .4 0 crassifolia '2,lots) 0 -Caulerpa P P F P racemosa (11 lots) F1 Caulerpa *4 sertularioides (2 lots) Cladophoropsis CL membranacea cn > (6 lots) Od 5 txj .0 F@ 0 C+ Ralimeda opuntia w 9: (13 lots) 0 Im Hatimeda > (D tridens 0 (i lot) > Em 'a Penicillus capitatus C+ j(3 lots) 0 0. Rhizoclonium F@ hookeri: tb 0 (5 lots) Uddtea co ca flabellum (a lots) V > > 0 0CD '4 CD 0 0 0 _aq m 0 0, aq .c0 A z r Oil NMI r- r' I r rn P 0 0 r 0 rt rt 0 cu P r GOOD 0 r x or w 0 @00 x Fwx 0 @0. r 0 to XW rt ;r POq m tA .. . ........ ................ ... ........ OD ;Q ...... .. .... m m rn ca c m m > c i 6m C*j r 450 Cc ref % AZC02 ret. %%% -A % -j -A 76 -.6 - ACabank 0 -.8 - % -.9 - 1.0 - ":C02bank 1.1 MAR MAY JULY SEPT NOV JAN MAR 1964-65 Seasonal LCO., and calcium losses on the Great Bahama H The solid dots are the average for surface and bottom (7m) values from 3 hour bank edge reference (25*15'N, 79*10'W). The open do 'ts are the aw: for surface values from a 25-hour drift station on the bank (24*57'N, 7,, W). The dashed line is the average for near bottom (5m) values frOir drift station. Vertical lines show diurnal range. IFig. 6. Loss of carbonates and calcium from Bahama banks with turtle grass (nraga=a 1.967) 451 CC/CL%. 0.610- 0 0 4 4 4 (CCr-ir_AYCL%. &A40. T -4 ---- 4 ;0 11 CL%. Calcium : chlorinity and "noncarbonate" Calcium : C1110rinity ratios on the Great Bahama Bank as functions of chlorinity. Solid circles are values obtained from samples collected in July 1964. Solid circles are values obtained from sam- ples collected in July 1964, Open circles are for September 1964. Ratios are in units of mmol liter' : g kg-'. Chlorinity is in units of g/kg. Fig. 7. Loss of calcium relative to chlorida accompanying photosynthetic and thermal stimulation of calcification in tropical banks.with' turtle grass (traganza and Szabo, 1967). _;A Areas of submerged vegetation in Florida estuaries frorr TaLmpa Bay to the Florida Keys. Fig. 8. Bottom marine meadows of south Florida (McNulty, 1968). 452 Meadows of South Florida Especially at the tip of south Florida in Florida Bay, turtle grass meadows are a principal vegetation type (Fig. 8). Extensively studied, their communities are diverse as suggested by species lists (Tables 9-14). Patterns of turtle grass distribution with depth on a shoal are mapped by Kissling (1965) in Fig. 9, Thalassia being found in waters deeper than I or 2 feet. Phillips (196o) reported similar zonation of Thalassia with depth (Fig. 10), other vegetation such as shoal grass (Diplanthera) growing in shallows. Another example of Thalassia distribution is shown in Fig. 11-from Lynts (1966b). Humm (1964) found 113 species of epiphytic algae on turtle grass under stable high salinity conditions. Patterns of bacterial distribution in turtle grass axe suggested in Table 14. meyers (1968) found large diversity in fungi and reported that some chaxacteristic species such as Lindra thalassiae axe im- portant in decomposition and mineralization of the old Th7alassia blades (Tables 13 and 15; Fig12 ). Studies of animals in undisturbed beds show very high diversities especially in Thalassia (Tables 9-12). Hopper and Meyers (1967b)from beds near Key Biscaynefbmd nematodes important in interactions with the fungi. High species diVers-tty curves and population curves with summer maxima, are given in Fig. 13- Sea urchins such as the poison spined Diadema (Fig. 14)vere common. Randall, Schroeder, and Starck (1964) found 1.2/m2 in grass flats. Although the bottom communities predominate there is a plankton component moving up from the bottom during the night and among the blades (Fig. 15). Data on the stable hydrographic climate are given in Fig. 16 and Table 16 (covering long-term salinity). A study of the dominant turtle grass (Thalassia testudinum) in benthic meadows at Miami Vas made by Jones (1968). By measuring oxygen release in enclosures placed over the plants, food contributions were measured through a year and extrapolations were made to the natural community from data on standing crop of biomass. Some of Jonest results are given in Figs'.16-19 showing relatively moderate changes during the year at Miami. Winter insolation, however, was almost half that in April and May, and gross photosynthesis varied similarly. Respiratory contributions of the plants were about one to two tenths of the gross production. These results do not give the whole community production under normal mineral cycling circumstances, but they do suggest the similarities of the seasonal regime. Hurricanes produced large grass windrows, but turned out to be a minor action per area (Thomas, Moore, and Work , 1961). Free water measurements of oxygen metabolism were made by Tabb, Dubrow and Manning (1962) in some inshore areas disturbed by salinity fluctuation and by Jones (1963) in less disturbed waters. Estimates of overall photo- synthetic productivity and system respiration (Table 17) compare with Texas data (Table 18) but are less than results in stable salinity zones studied in Puerto Rico and one measurement at Long Key, Florida (Odum, 1957) in Fig. 20. Erratic salinities in southwest Florida waters (Fig. 21) contrast with more stable conditions near the Gulf Stream (Fig. 16). 453 Table 9. Invertebrate animals in Florida turtle grass (O'Gower and Wacasey, 1967). DOMINANT SPECIES (IN ORDER OF DOMINANCE) INDiplanthera, Thalassia, AND SANDBEDS,KEY BISCAYNE AND VIRGINIA KEY Area Diplanthera Thalassia Sand Key Biscayne Onuphis magna Loimia medusa Clymenella mucosa Nothria stigmatis Onuphis magna Divaricella Clymenella mucosa Codakia orbicularis quadrisuicata Anachis avara Diopatra cuprea. Divaricella Chione cancellata quadrisulcata Euclymene Codakiaorbicularis . coronata Chione cancellata Alpheus normanni Virginia Key Phascolion sp. "a" Codakia orbicularis Batillaria minima Chione cancellata. Chione cancellata Anodontia alba Sentiodera roberti Amphioplus abdifus Amphiodia pulchella Prunum apicinum Loimia medusa Panopeus occidentalis Notomastus luridus Terebellides stroemi Table 10. Diversities and other properties of grass beds in Florida (O'Gower and Wacasey, 1.967), DESCRIPTIVE INDICESFOR COMMUNITIES IN Diplanthera (D), Thalassia (T), AND SAND.BEDS, KEY BISCAYNE AND VIRGINIAKEY Key Biscayne Virginia Key Indices D Jr S D T S 'Fisher & Williams a 16.202 19.437 5.578 10.434 15.439 3.932 2Dahl s/a 0.946 0.607 0.599 1.135 0.641 0.609 3Authors Md./ji 0.264 0.413 0.214 0.108 0.740 0.023 ; Index of diversity. Index of uniformity. ,,ndex of dominants. 454 Table 11. Fishes trawled in shallows in which bottom meadows'are important (Roessler, 1965). -The number of individuals per tow con Index diversity (a) based on Fisher's pared to the expected values of a negative bino- Loganthmic distribution for trawl nmpU3 col. mW distribution for selected species lected in Biscayne Bay and comparison with ob- served data Coeffi- Species Mean cient Of Chi- contagion square df. Number Num. Index of - Area of indi- ber of diver- Standard Chi di. Area 1, day vid.ah j?e- sity, error square cies Syngnathus floridae 0.80 457.49 Afonacanthus ciliatu8 1.80 1j663.9 Day Apogon alutus 0.25 2 1 1 on plurnier@ 32 0:' 7 1 1,052 31 6.003 1.0780 17MS** 4 Haem 10.55 210 902 661 11 316 26 6.813 1.3325 3.759 4 LachZI lamus maxtMus 0.80 0.7496 0.97 1 Spatisoma rubripinne 27.60 3.0782 6.20 6 M 23 8 4.328 1.6100 1.688 2 Atonacanthus hispidus 7.60 2.8899 7.89 7 Night Sphaeroides spengleri 0.45 0.8422 0. 22 1 1 1,186 35 6.934 1.195S 15.933** 5 Diodon holacanthus 0.30 7.0069 0.06 1 11 64 38 9.699 1.5840 7A58 7 0 (anus beta 0.20 464.93 Affspecles combined 52.00 3.4593 6.10 8 M 90 21 8.679 1.9251 5.327 4 Area 1. night Significant at the 99% level. Syngnathus floridae 0.95 433.45 Apogon alutus 1.20 1.6674 2.84 2 Haemulon plumieri 18.50 1.8670 7.74 8 LachnDlaimus, maximus, 0.85 1.7292 0.39 2 S;)Gr,,,,a 'b" 'F''"' 12.70 1.5564 5.47 5 .,gnaconthm cl iatus 0.70 1173.7 '%Jo.acanthus hispidus 5.35 3.5439 2.34 7 Onsanus beta 1.15 402.23 All species combined 44.30 2.6202 3.12 7 Area 11, day Syngnathus floridae 1.05 3.3716 1.40 1 Hacmulon plumieri 1.30 1.2385 1.42 2 Calamus arctifrons 0.50 948.78 Lagodon rhomboides 0.30 7.0069 0.06 1 Spariso a rubn* inne 3.00 1.5343 2.71 5 31onac..thus cy,.'u" 2.00 1.0559 4.02 3 Afenacanfhus hispidus 5.15 0.6137 5.44 4 Sphacroidcs spenglM 0.70 1.9823 1.35 1 All species combined 15.80 1.3119 5.78 7 Area II, night Syngnathus floridae 1.60 228.38 Apogon alutus 0.30 7.0069 0.06 1 Haernulon plurnim 2.90 0.9448 4.47 4 Calamus arctilrons 0.60 9.3125 0.19 1 @agodon rhornboides 1.25 3.3244 2.87 2 Sgrisonia rubripinne 2.10 3.0965 4.23 4 .%jo,taranthus ciliatus 1.70 4.5853 2.45 3 .@fonacanfhus hispidus 7.60 4.2174 18.34 8 Lac(ophrVs quadricornis 0.45 2.4288 0.50 1 opsanus beta 0.70 483.82 Sphacroides, spcngled 0.45 2.4288 0.50 1 All species combined 23.20 15.441 4.49 3 Area 111, day Harmulon plumicri 0.05 431.871 Sparisorna rubripinne 0.40 1,369.8 Monacanthus cilictus 0.10 448.85 31onacanflaus hispidus 0.25 471.50 All species combined US 0.9871 2.78 2 Area 111, night Eucinostomus argenicus 0.95 0.6957 0.73 1 11acmulon plumieri 0.55 920.99 Sparisoma rubripinne OAS 939.95 3ficrogobius microlepis, 0.45 434.24 Monacanthus ciliatus, 0.25 747.39 Monacanthus hispidus 0.40 869.46 All species combined 4.50 1.1921 4.09 4 IExample of a single individual in aU 20 samples- approaches the Poisson distribution. Table 12. Some mollusca-with bottom vegetation in Florida (Moore, 1963). 455 Gastropods Number per square meter Bittiurn varhan 2170 Rissoina chesneli 5440 Caectim putchellum 13220 Mitrella lunata 130 Pe'ecypods Brachidontes extistus 7940 Amygdalum papyria 230 Table 13. Trawl catch in shallows off south Florida (Pbore, Jutare, Jones, McPherson, and Roper (1963). - Numbers of shrimp and fish captured in trawl. samples from Joe Kemp Channel and Sandy Key Basin in Florida Bay, April, 1959, a period When salinity values were near that of norma,l seawater in both areas. Joe Kemp Channel Sandy Key Basin Catch from 5 trawl Catch from 4 trawl Species hauls. Bottom hauls. Bottom salinity 36.5 ppt salinity 37.2 ppi Crustaceans Periclimenes longicaudatus 36 25 Tozeuma corolinensis 20 22 Hippolyte pieauracantho 7 129 Leander poulensis 7 10 Thor floridanus 5 12 lotreules fucorum 4 8 Fish Lagodon rhomboides 28 115 Gerres cinereus 11 3 Lutionus.synagris 9 6 Sairdiella chrysuro 2 14 Orthopristis chrysopterus 3 11 Table 14. Bacterial distributions in turtle grass of Florida (Wood, 1965). Occurrence of bacteria in various estuarine environments Cpercentage of species) Water Sea-grass commuzuty Species Bottom i m from bottom Surface Bacillus subtilis 45 39*5 22 10-25 B. megaterium 19 7 5*5 0 B. sphaericus 0 7*5 0 0 Corynebacterium globiforme 0 7-0 0 0 C. flavum 0 0 0 10 C. mildrium 0 0 0 5 Actinomyces spp. is 0 5*5 10-25 Staphylococcus candidus 0 8 8 0 S. roseus 0 8 0 0. Mycoplana dimorpha. 19 23 54 40 M. citrea 0 0 0 5 Sarcina lutea 0 0 5*5 0 Pigmented strains 20 38 27'5 50 Ratio gram pos.1gram neg. strains 1-9 210 0-7 0-9 C entral Sand Bar- Declivity Intertidal Intertidal Shoreline 0 x ), Xe 0 0 0 0 0-00 yo 0 0 X 0 00 X)Iq 0 "'SE141 XXI 0 40 xe 0 0 R; x Ix 0 0 0 0 0 X)@ X A 0 46 0 RY 'U, XF >16 NDIANT 0 Y14! Y, v distribution of Thalafsia testudinum. RelativL A X X 0 0 OX Fig. 9. Zonation of turtle grass diminish@- 0 0 xOX ing as water shoals (Kissling, 1965). X*x 0 0 "X 0 0 x@ee 0 Schematic drawing of Mlch Drive station showing intertidal zones and inaxinium depth declivity with location pf grasics. These symbols are tised: 9 -Dildanthern (INI)Ifia in late winter and spring); X -Thalassin and syringodIUM. Fig. 10A. Zonation of bottom spermatophyte plants by depth in Tampa Bay, Florida, (Phillips, 1960a). 457 SHORE - - -------------- smTL NHTL DIPLANTHERA- MOST ABUNDANT RUPPIA- SPARSE NLTL R UPPIA- MOST ABUNDANT DiPLANTHERA-SPARSE THALASSIA- SPARSE SLTL THALA SSIA- MOST ABUNDANT SYRINGODIUM-ABUNDANT ONLY WHEN THALASSIA IS SPARSE DIPLANTHERA-SPARSE RUPPIA- SPARSE Schernatic drawing of seagra.- zonation in shallow water. Valid only in areas with salinitN oi er 25.0 o/00. Abbreviations are: SLTL slack lo%v tide line NHTL - neap Iii0i tide line SHTL spring high tid e line NLTL - neap low tide line Fig. 10B. Summary diagram of bottom olants relative to depth in Florida (Phillips, 1960a). =very dense, E2dense-modera ElPatchy ....... ... -Z:. NAUTICAL MILES 0 Distribution of marine grasses (Thalassia Irstudinum Kanig), showing intensity of growth, in Buttonwood Sound. Fig. 11. Turtle grass bed among cays of south Florida (Lynts, 1966b). 458 DEVELOPMENT OF FOUICOLOUS FLJNGI ON hle/aSiO leStudiflum K6NIG IN BISCAYNE BAY, FLORIDA GROWTH OF THE TURTLE GRASS FLARING PLANT CYCLIC VEGETATIVE DEVELOPMENT FRUITING ZAKIL -SEPTEMBER DEVELOPMENT OF THE MARINE FUNGUS, MYCELIAL DEVELOPM@NTMOISTLY WITHIN BROWN LEAVES INTENSE LINVRA thalassia4p --PERITHECIA ABSENT PERITHECiAL ASGOSPORE PRODUCTION RELEASE SEPTIOCT NOVIDEC, JANIFEB MARIAPR MAYLJUNE JULY I AUG FREOUENCY OF ISOLATION OF FUNGI OF GROUP I I NUMBER OF TIMES ISOLAtED NONE Z22 i no 'OCT NOV'DEC 44N'FEB MAR'APR MAY'JUNE --------- T-M Schematic showing typical development of foliicolous fungi on turtle grass in Biscayne Bay, Florida. Fi&- 12, $eaj3g=j p&tterzi of .:ftmg;1 in turtle grass beds of south Florida (Z&Yers 19ffi)-, Table 15. Fungi in turtle grass Obyers, 1968). Fungi Present in Washed Thalassia Leaves Group I Group Il Goup III Abundant, multi-isolations. Scattered occurrence, Uncommon, Dominant mycota 2-8 isolations only single isolations Aspergill- Altemaria Acrotheca Monocillium Cephalosporiwn Aureobasidium pullidans Bohytis cinerea jYigrospora spherica Dendryphiella arenaria Cerafocystij or Cylindrocephalum Fusidiurn Phialophora Honnodendron Culcitalna Geolrichium Phomopsis Laby,inthula Cylindrocarpon Gonabolryum fuscum Spicaria violacea Lindra thalassiae Fusarium Humicola Torula P'nicillium Phoma Lutworthia Zygosporium Mwonii Unidentified @on Sporotrichium Mondia Unidentified sporulating mycelia Ascomycetc Varicosporina ramulosa Unidentified pycnidial forms Unidentified sporulating mycelia 459 TO MIAMI OBSERVED ArIANrIC ---- THEORETICAL OCEAN SCALf: IN MILES so. 0 1 2 IMS LABORATORIES 70- 60- 'S 25-40' U. So- 40- 30- 20- SAND ISLANQ'2@1 SITE C KEY 10- BISCAYNE LEGEND! COLL.140. 654 1 655 1-1 673 1 674 1 679 6116 6" 0. Land 0 j 1@ 1'5 2b A .3@ i5 46 45 50 55 60 65 Sand bw 25-3d NUMBER OF SAMPLES .4 Tholassia beds y Relationship of number of taxa, found to number of - samples examined Location of collection site (Site C) in Biscayne Bay (Miami) Flon"da 90, PERIOD OF COLLECTION 80. 70. Is w 60- 40- w 70- Z 60- 7A 0, -@j 50 - T.FISTULAT(Z 101 652 6U 655 656 657 658 663 664 665 666 667 669 670 671 672 673 674 6 6 679 686 638 6;5 764 40- 668 C COLLECTION NUAB ER 30- Population density or number of specimens over the S. PARASITIFERAI,, entire collection period w 20@ U ,% IG.TYPICA M,SCJSSUS 654 655 6S7 6S8 664 6,r, 613 17, NUMBER Of VARIOUS COLLECTIONS Percentage frequency of occurrence of four species at Position A, Fig. 13- Species diversities of nematodes in turtle grass beds of south Florida -(Hopper and Meyers, 1967b). 100 10 -80 0 0 M _U 0 -60 0 3000 60 10 00 2000- 91 LA ZA 30 M 1000- .6 3 _U Tesi dva@0161 (mlffi@tltls) 30 z Length frequency distributions of the test ciameters of Diadema antillarum in four collections 20 from a shallow Thalassia flat in Lignum Vitae - kI.I.:.- .. All 10 0 Channel, Florida - Keys.. Distance between the abscis- z sas of the four plots proportional to the time intervals 0 0 between collections. < A M J J A S 0. N D J F M A 0 - MONTH Fig. 14* Sizeof poison spine.urchins in turtle grass beds of south Florida (Randall,.Schroeder, Fig- 15- Zooplankton among the Florida Keys (Woodmansee,.1958). and Star-ck, 1964). j . Table 16. Characteristics of bays of south Florida (Tabb, Dubrow, and Manning, 1962). Long-term salinity characteristics of 10 stations alonc, the salinity gradient during the period August, 1957, through May, 1962. Long-term salinity Table 18. Comparisons of Florida and Texas by Tabb, No. monthly Bottom salinity in ppt aii Station No. observations Lowest Highest Average percentage seawater Dubrow, and Manning (1962). Florida Say 10 28.4 47.0 35.5 100.0% Coot Say 2 55 14.4 41.1 26.6 76.0% Coot gay 3c 65 8.0 41.1 25.3 72.2% Tabb, el al., (1959), and Tabb and Dubrow, (1962), contain the raw datb Coot Bay 5e 65 5.9 41.0 22.1 63.1% from several 24. hour observations, not summarized here. Whitewater Bay 1 55 4,0 40.0 18.7 53.4% Whitewater Bay Result; of free water diurnal curve studies in shallow Texas bays V 54 0.0 37.3 15.4 ".0% having conditions similar to those in Coot and Whitewater Bays. (Reproduced Whitewater Bay in part from Odurn and Hoskin, 1958.) Vil 52 2-2 38.7 17.9 51.1 Y. North River Systems with both plankton and Vila 0.0 36.7 13.2 37.7% bottom mud components P R K P/R East River 45 0.0 38.0 11.7 32.1% Whitewater Say (Similar to Cr1 Bay) XII 47 12.0 37.6 28.1 80.2% Cedar Bayou, July 22, 1957; salinity 24.6; 1.5 M deep 5.6 17.6 is .318 Mesquite Bay, July 22, 19571 salinity 15.5; algal bottom, 1.2 M deep. 3.8 7.3 1 2 .520 Copono Bay, Aug. 18, 1957; salinity 11.8 2.1 6.2 6.7 .339 Copano Boy, Oct. 20, 1957 1.6 1.65 - .970 Aransas Boy, Rockport Pier, May 19, 1957, 1 M deep, salinity 21.0 6.3 4.8 0.6 1.340 Table 17- Productivity and respiration by the diurnal curve Aransas Boy, Rockport Pier, Oct. 20, 1957, 1.3 M deep, salinity 18.7 6.1 7.8 1.8 .781 method in shallow bays of south Florida (Tabb, Dubrow, and Manning, 1962)_ Systems with dominant bottom plant and animal communities; plankton unimportant. P R K P/R Results of metabolism studies at three stations. ISimilar to Whitewater Boy Vill Laguna Madre, Texas, Mean, Temp. Satin. Diplanthera-coze 1957, annual curve. 4.3 5.6 0.2-1.4 .758 Station Date P R K range range P/R Redfish Say, Part Aransas, Texas, in C* in ppt. Thalossio beds; Ransom Island, mean of 5 days in oil seasons. 11.4 17.0 0.6-1.7 .670 Coot B@y 3c July '58 7.50 14.10 1.59 [email protected] 13.2-14.7 .531 3c Oct. '58 1.10 4.97 .96 23.0-26.5 15.6-18.1 .221 3c Jan. '59 1.50 1.30 .18 16.0-19.0 18.9-23.0 1.150 3c Apr. '59 2.44 4.68 .89 24.0-27.0 26.7-27.7 .521 Whilewater Boy Vil Apr. '59 8.22 7.03 .85 24.0-27.0 25.1-26.4 1.110 Coot Boy 5e Jan. '59 .81 1.66 .44 15.0-18.0 18.1-20.5 .490 4=1 (P) -Pbotosynthesis; gm 02/.W/day (R) -Respiration; gin 02/.Nl'/day (K) -Diffusion constant; gin 02/,W/hotir -4 OQ a 0 0 c 0 c 0 0 0 00 o o 0 0 0 0 0 0 o o II I I- I I I I I'> I 1@ ,N 0 W I"% m go rt " =r rt 0 " (D x m lb C@ W 0 ol s - C13 H. ol r- -A co fn ry CL 1-h it pi n 0 m cn (D :C P. Ch " = rT m m r_ r- m 0 0 lb 0. " ra . .-- @> rt :3 rr M @o IZ oll ?-4 C6 0 m rr 0 H. t_n n !X P) 0 rT Ph ol C. m 0 0 0 > pt c H V4 03 iF " t.L rt 2) lrt* :3 g H. = P. I -- pq lb eb lb @o m (D m En 0 a, 0 m CA 0 -:to J. < M a. LO (D rt OQ 0 lb :0- 0 k m fD m CL En G) > r? (, 0 %D 0 rt (D :31 0 C,@ -0 0 M 0 rIt -j rt m 0 m 0) L4 CL x 0 0 0 v m tj m lb z I-h -4 -4 m 0 rt ID H- z rA pa 0 M :3 m 0 m w lb 00 n lb 03 m ft Sb (b lb 0-- m .. 0% m 03 0 rt 0 rA W- r- M rt P- rt J@ C" CO 0 0 0 0 06 0 33 G 0 10 k4 0 0 0 0 0 C, 0 0 0 U, Ln 0 1 11 o -.) 0 0 0 0 pt 14 lb It 0 0 n lb -4 P3 463 J'AN I FEB MAR APR MAY 1 JUN JUL AUG I SEP OCT NOV I DEC THALA%IA GREEN LEAVES-WET STANDING CROP 1 5 - 1.5 V V 1.0 1.0 k k 19 @5 -0.5 0.0 0.0 25- THALAIA WET BIOMASS -25 F LOWERS FRUITS 20-- ................ G LFAVkS 20 NOk -OPEE NLEAVES 15 15 X:@:@ r'"ORI S H 001 S (k ng) ,n2 M2 10 10 5- -5 ROUT S 0 0 @@THALASIA DRY BIOMASS -3 FL C' W E R S (h-g U I qkg M2) En -2 @HURT SHOOTS flool S 0 0 EPIPHYTES WET STANDING CROP V. ve 004 0.04 VC-M) 0.02-. 0.0Z 0.00 JAN F B I MAR I APR I MAY JUN JOL AUG SEP OC "N'O V DEC 0.00 Seas@nal variation in standing crop of green leaves and biomass of total plant material (wet and dry weights) for Thalassia and standing crop of the epiphytes. The data for Thalassia are bas(,d on one-tenth square meter samples at Bear Cut, Miami., with the vertical lines for standing crop representing ranges of observed occurrences from bell jar exp(,rtments. The data for the epiphytes, in grams per centimeter of Thalassia le,af blade, are weights obtained in connectio.n wiith the manometer experiments. Fig. 17. Mass of benthic plants in a south Florida turtle grass bed (Jones, 1968). 464 JAN 1 F MAR 1 APR 1 MAY 1 JUN 1 JUL AUG SEP OCT NOV GROSS 300- -300 A A 200 -200 ( M1 N M1 07R) @rn@ hr 100- -100 0 N E G L/ NEIG LJ 0 - NET - 200- N -200 A A 100- -100 MI N MI WK -h,) - -------- N@ hr 0 NE C LIJ 0 -100- --100 RESPIRATION JAN I FES I MAR I AP R MAY JUN JUL 1. AUG SEP OCT NOV DEC Seasonal variation in primary productivity per unit area (A) by the epiphytes of Thalassia. These data are derived from those in Figure I? on th(-, hasis of severai assumptions. Fig. 18. Seasonal record of primary production and repsiration of turtle grass epiphytes in south Florida meadows (Jones, 1968). ;PIRAT41ON 465 JAN 1 FEB MAR 1 APR 1 MAY JUN JUL AUG SEP OCT' NOV' DEC 1400- GROSS 1400 1200- 1200 1000- 100,0 Soo- Boo 600 -600 Mi M1 k-mfMr) 400 400 200-. 6-200 0 10100- NET 1000 Soo- Boo A V A 600 -600 400 400 7 MI t M1 -m r -h-r @-Mxw-) 200- -200 0 0 -200- -200 -400- -400 -600 RESPIRATION 600 FJAN_ I FEB I MAR I APR MAY JUN JUL AUG SEP OCT NOV DEC] Seasonal variation in primary productivity per unit area (A) by Thalassia. The heavy curves reflect the seasonal trends. Data from "bare sand" bottoms are represented by the letter "s." Other symbols are as in Figure 7. Fig-. 19. Seasonal record of productivities and respiration of isolated turtle grass plants in chambers (Jones, 1968). 466 01 2 1 . ... ....... P 4F "I time W mouP4 TATLE CAASS-4;;" Pate of oxygeri change (Q) and pri - mary produption (P) on an aren, bmis in.maqs@@s 0, %rz-1ter movijig-over br,-ds of turtle grass along the cau.@ewav on Loiig HeY, flor,;Aa, August 14, 1955. The cxygeti eurve (iniddle graph) is used 'iuring the day so as 1 ,1 eorrcct for diffusion loss to derive t"Ac prodtiet;on %n-e (P) froin the -axy- gen rate rif-Annge curte (t2,).' Parcels @Vere followed wiih fl!wrescein dvr; by a wading ob- ierver-. , PoInis are the rriewi dilferences between duplicate &ainples, (Table 3). Current velocity varied from 0 to OM m/.-cc. Jz4yer chnnqros (,,n-Y.1L) nrc, nwring dye spots, otei, Thallasria g-al fals Auj-. 14, 19J5, Long Key, Fla. Time of Deptb Oxyger Oxygen 0;Iygen , axygvr in Ps': In in at start At en," an7 stal E ztxrge ch ze mules gnilrOAAr 2:35 7 0.9 6. R5 7.06 6.91 7.10 SG 3: M Pir; N 0.1) 7.21 7.49 7.20 7.44 0.25 0.60 6A1 P", 5'1@ 0.9 7.79 7 90 8.04 T. G., --0.21 ... 2.1 M24 pw A4 0.75 5.47 8.46 5.80 5. jo 7:," Im 4.9 '. 05 4.47 4.43 4.0 4.52 C 0 Wiz.@ 20,, Primarv vroduction measurement from oxygen changes in free water (Odum, 1957). L IWO 0 3-0 RAINFALL IN. INCHES SALINITY AS PERCENTAGE OF SEAWATER (35%.) 2. a 8 8 8 o "o 8 9 8 8 o "o t S *o 8 o o" ol 26 8 8 8 < CD 1-- - to 0 AT 10, CA 0 0 N E, 0 CA 0 NO :AT. < (D Q , > CL (1) -4 lb o 0 0 z 0 ? 0 -71=li A A NO DATA NO DATA NO DATA 0-0 a NO DATA 10 OAl^ NO DATA G 14 NO DATA ti) M (D r- ol @: (D -90- 'DATA. C+ :3 :3 cll@ -LL HITEWATE WHITEwATER SAY < ]RAINFALL AT NORTH RIVER S ER BAY WHITE@ATER BAY JJW :R .1 FL MINGO MT. a 3ar Cr 2: 0 0 C+ 0 to 0 -0 F+j - ETA IR CL 468 Seasonal variations in growth rate and reproductive activity,possibly in phase with the pulse of photosynthesis of the communityyare given in Figs. 22-23. Principal,swimming members of the tropical meadow include the commercial pink shrimp Penaeus duorarum. The grass beds serve as nurseries for the fast growth of these shrimp in Texas and Florida,correlated with spring energy pulse (Idyll, Tabb and Yokel, 1967) (Saloman, 1965). In Texas they migrate out the passes into the Gulf around the first of June. In Florida they migrate west, the larger shrimp being caught in the fishery near Dry Tortugas. The steady yields of the Tortugas pink shrimp fishery suggests a stable pattern of recruitment from the high diversity turtle grass nursery of Florida Bay (Fig. 24). From free water.changes in oxygen Jones (1963) estimated dry matter production in waters including some turtle grass and some patch reefs to be 0.8-2.0 g/m2/day. Turtle Grass at Redfish Bay Texas A case history on which several investigators have made studies over a several year period is Redfish Bay, Texas (Fig. 25). Some principal data are assembled as Tables 19-21 and Fig. 25. In Fig. 26-27 are studies on sediment and ostracods by Grossman (1965) and Kornicker (1964b). Bacteria were studied by Volkman and Oppenheimer (1960, Fig. 28). Larger animals were collected in drop nets by Hoese and Jones (1963, Fig. 29 and 30). Trace elements (Tablesig- 21) and amino acids in waters amidst the grass are given by Park (1963, Fig.- 31). Total gross photosynthesis and system respiration were determin6d by freewater measurements of oxygen and carbon-dioxide (Odum and Hoskin, 1957; Odum and Wilson, 1962). Fig. 32A shows 24 hour records of oxygen and pro- ductivity. Fig. 32B shows records in a large enclosure set down over the grass. Fig- 33 (Odum, 1968) summarizes the data-on productivity and sums other seasonal records in these grass beds. Fig.'34 shows results of Parker (1966) with radioactive tracer uptake experiments using 4 element I p. Fig. 35 (Odum, 1963a)has simplified diagrams of carbon and zinc cycles in turtle grass. See Conover (1964) and Kornicker (1970) for additiopal details. DISCUSSION Salinity Adaptations The plant members of the diverse tropical high salinity meadows have varying tolerances and abilities to succeed in lower and more variable salinity conditions. In system conditions which are classified as other system types McMillan and Moseley (1967) report salinity tolerances for 4 species (Fig. 36). Meyers (1968),studying salinity adaptation of fungi, found species important to the high stable salinity Thalassia beds not as well adapted to low salinities as some other forms (Fig. 37). In general the species with least tolerance predominate in the high salinity situations where the salinity adaptability has little use and presumably is an energy drain. In Texas Ruppia takes over when there are surges of low salinity water and Diplanthera when hypersaline regimes develop. In Fig. 38 and 39 Hammer(1968) so- 469 70- 1959 1950 60- -131959 .14959 El 462 -t-@+ + - + @50- E E ix 40- 1959" W W 1938 @9611 N. XEY LARGO 1959 20- 10- t-S.W. POINT 19652 0- j F A M i J A S 0 N Growth of known year groups from Bermuda (1937-191 from the Miami area. Fig. 22A. Growth of urchins (Moore et al., 1963). LO - 11%%% % 19 62 - 63 .6 % % .4 .0 0 IN 0 Mean relative gonad volume of the population of Tripneuiuj venlricoius from Virginia Key, Florida, in 1962-63. Fig. 22B. Growth of urchins (McPherson, 1965). 470 JAN FEB. MAR. A JUN, JUL AUG SE P, i OCT NOV DEC .9 PR 4-@ 1936 0 BERMUDA .4 1.2 1946 BERMUDA LO LIJ 1959 MIAMI -J > 'OkI .4. 1960 MIAMI A 1961 % %A MIAMI .4 Seasonal changes in gonad volume expressed a. 10. Gonad Volume in Tripneustes. Test Volume Fig. 23. Reproductive cycles in urchins (Moore, Jutare, Jones, WPherson, and Roper 1963). 471 INDEX OF FISHABLE STOCK 2.5- MONTHLY TREND ANNUAL 2.0- TREND 0 0 1.0 - 0 00 1.0 o AI-A . V , V-- 0.5- 00 Ole 0 0 -0.5 0- 111 Iml am] IJI ISI INI lil IMI I T-1 I I I I I I I I .7-L- 0 44 IMI IMI IJI IS[ INI 141 IM IMI ]JI ISI 1111 M J S N '.. . Ch 1956 1957 1958 1959 non'n J M M J S N M S j N J M M J S N I I I I I I I I I I I [it IMI I I ]JI 1 1 141 1 1 IMI Iml Ijl ISI I I I I I I I I I I I I I 15 - 2 0 - 0 il -25 - A 26-30- 0 0.0 /6 a 6 a a 4 31-40-P va % a 0. W' 41-50- a ..DOMINANT MODE Wo z 51- 67 - "x C a 68+- 0 E F G MODAL-.SIZE DISTRIBUTION: COMMERCIAL LANDINGS 1956 1957 1958 1959 < 13 z 15-20 0;; 21-23 IL W 26-30 cc 41- 0 W 51-67 68+ I 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 RELATIVE SIZE COMPOSITION: COMMERCIAL LANDINGS Analysis of pink shrimp statistics for Sanibel- Tortugas area, 1956-59. rLgL. 24. Seasoba-1 patterns of pink shrimp catch off southwest Florida Ocutkubn ig6o) 472 41@ N4w Gulf 1960 of M exico Ct of dredged Channels 34 5 4ni s Aransa.i., Poss . Turtle gross Institute Ransom. 0.5m Id @... @ Port "I*" Aronsas@' Station Ransom <,dr.dged -TI jv Map of Redfish Bay near Aransas Pass, Texas, indicating the study area, the 5 stations, the intracoastal channel, and the RansOrn IslandStation. Fig. 25. Redfish Bay, Aransas Pass, Texas a shallow area or turtle grass (Odum, 1963). TOANSECT I STATION 60:STATIO% 2 AA_ STATION 3 STATION a STATION S No - Ge 06 ..1 me. 42 0 (.54-) us- -901.3.-1 so me-5061.31-1 60- md-115#1.22-1 So. S.D.. 4.6 SO. S.D. - 6.3 S.D.-S,70 50- S.D.-S.G# so- SA. AC' 40 a- -a- 40- 40 so- 30 '0 30 - 0 20 20 20 .a- o .0 .0 20- 20 'a It a 0, 2 -25 0625 0039 25 039 -25 OE:5 0039 -#-:2'5 OL D031 Z5 01:r@ Do. Fig. 26. Sediment properties in station transect shown in Fig. 25 (Kornicker, 1964). "W SEASONAL VARIATION IN COMMUNITY STRUCTURE AT STATION I DEC 9 FEB 5 W*A 5 MiAR 23 27 #73 PERISSOCIT-IRME. UO.C _-- - --R!L- - --K-3-- - ftRACrTMERETTA WLTICARINATA7 "PLOCYTHERIDEI PONOEAOS- WAPLOCYT@CRIDEA PPOSOSCIOIALA@ CTPAID(IS Cf. t TOROS& IONES@ XESTOLIBERIS $0_ CAWLOCTT@EPA 17) W C, @E . 1O.1SON' LOXMOMC@ AURILA FLORIO-' OF EMPTY CM@Es IN WE,GHTED @EPAGE ILES SEDMENT (,nM -51 01 ALL UMIkES PtQ'SSOC 'TMERIDEA RUGATA7 MA RACYTHERETTI WLTII.-T; '&PLQCVTMER PONDCOOSA@ 0 Ek @OOSCID-11-1@ CVPRIDCIS Cf C, TOPOSA UQNES@ NESTOLESERIS SO 'WPLGCYT"E" (71 W CY I.ERIAA 10-30ft@ "ISUB"OMB DEA AUMLA IILORIO@. ME .5 JULY 23 AW, .0 SIEPt. 20 PWGATA@ ..IACYTHERETIA WLTICAMINATA 'APLOCYTHERIDEA PCNDERqSfi@. @PLOCTYHERIOE& PRCDOSCIOIALA@ CY9410W Cf. C TOPOSA (JONESL IMSTOLEDERIS So_ CAWLOCYTHERA 171 W_ CYT.E". JOH.SON.- Low -O'c- PURISUS@OMBOIDEA- AURILA FLORtDANA r Ostracod population structures in samples from station I,' averaged population structure, and population structures of empty carapaces collected from sediment at Station 1. -0.."0 YOTIL OSTRICODS 0 '00 -C-ts Es I UP MY Average monthly abundance of all Ostracods, Aurila floridana, Loxoconclia PlUrisubrlzontboidea, and - remaining species . in Redfish Bay. Ostracod abundance based on samples containing not less than 150 specimens. Fig. 27. Ostracod associations and seasonal distribution in Redfish Bay, Texas (Kornicker', 1964). SEDIMENT PROFILE a SEDIMENT PROFILE depth 1. depth 1. 0 0 60 so 130 120 474 I" ISO 0 10 20 30 40 50 60 70 89 90 0 Q5 to W 20 Z5 W 35 0 10 20 30 40 50 60,70 so go % lass in argon ic carbon after % "go. ic c.,b- % led. is depehi, carbon MW 40 days at 4-C 40 days .' 4C 0 10 20 30 40 50 60 70 00 90 0 1 2 3 4 5 6 7 8 9 0 10 20 30 40 50 60 70 80 go % send , shell. sea gfols'claj X 107 % send . shell, sea g,ats,Clay "'abic bacterial Population MI 110 aerobic bacterici population SEDIMENT PROFILE G SEDIMENT PROFILEd depth in depth I. m 17- 70 0;7 -4; 0 Q5 to a 2P 25 AD 35 0 10 20 30 40 50 60 70 80 90 0 05 UO L5 20 25 0 10 20 30 40 50 60 @10 so 90 % organic carbon % less i c % 4; 0,for! c.1ba. ft., % .'gartic carbon Its% in of"a"ic carbon after day, .1 4% 40 days at 4% 0 1 2 3 4 5 6 7 8 9 0 10 20 30 40 50 60 70 80 90 0 1 2 3 4 5 6 7 0 9 0 $0 20 30 40 50 60 70 80 90 X to % land 0.11. 11. X to ? % derobic pact.; I poput.fitt. _.h. act i.1 ...... fish a. .knalysis of sediments from station 5 during (a) (b) February, and (c) (d) March 1959. Fig. 28. Distribution Of organic matter and sediments in short cores in turtle grass,Redfish Bay, Texas (Volkmann and Oppenheimer, 1962). TOTAL CATCM SEA LEVEL -100 Neoponope iexoma 300 Par,," d.o,.- L.can.0 Par- 50 Goo too 30- 30 4 400 5. to too- 0- J F M A I J 0 N D Correlation of biomass of two species 0 'j with temperatures at time of sample. k IA j _j 0 0 0 j F M A U j j A 9 0 N0 0 Catch of pink shrimp, Penaeus duo- rarum. Total biomass (CXChiding larger species) correlated with bay water level at time of sample. 100 gms = 0.85 gms/m2 in all. graphs. Fig. 29. Seasonal records of biomass with drop net in Redfish Bay turtle grass (Hoese and Jones, 1963). 10 L5 2@ 35 % organic Car ban [0 475 Calfinectes sapidus ISO- Polaemq@etes 200@ loo. Ioa- so- 0- 0- i F M A M J J A S N 0 1 F 'M A M J J A S 0 N 0 Catch of -grass Arimp, Palaemonetes Catch of blue crabs, Callinectes sap!- Pugio. dus. Lcgodo@ rhomboodes 300. Leiosfomus xonthurus Go- 200- 40- 2 100- 20- 0 0 A M J J A S 0 N 0 j F M A M j J A S 0 N D Catch of spot, Leiostomus xanthuras. Catch of pinfish, Lagodon rhomboides. Fig. 30. Stocks of animals in turtle grass, Redfish Bay, Texas (Hoese and Jones, 1963). i F M Table 19. (Parker, Gibbs, and Lawler 1963). 476 Summary of chemical analyses Sample C. pp. Fe ppeo Mrs pp. Local bay watersl (5) 0.34-9 (15) 5-78 (3) 5-15 Redfish Bay sediment 0.4 1000 92 Grass, Thalassia testudinum root 0.5 366 14 blade 0.34 279 178 Grass, Diplanthera wrightii 4.0 735 Mullet, Afugil cephalus 0.5 178 19 Pinfish, Lagodon rhomboides 0.6 48 24 Fish, Afenidia sp. 0.6 160 20 Brown shrimp, Penaeus aztecus OA 75 10 Grass shrimp, Palemonetes sp. 2. 285 26 Crab, Callinectes sapidus 0.3 166 42 Jellyfish, Physalia 1. . ..: -.. The water concentrations are in parts per billion. The number in parenthe@is gives [be number of samples between the ranges Table 20. (Parker, Gibbs, and Lawler 1963)- Cobalt, iron. and manganese inventory for a grass flat Dry weigbt' ca Fe K. Sample Description g/m2 g/,l -9/-! 1118/m," Bay water I rn depth I X 106 0.5 30 5 Sediment per cm depth I X 104 4.0 1 X 104 920 Thalassia summer crop roots 2800 1.4 1 X 103 39 blades 200 0.07 74 34 Diplanthera summer crop 568 2.3 422 627 Mullet max biomass 2.3 1 X 10-3 0.4 4 min biomass o.06 3 X 10-5 1 X 10-2 1 X 10-3 avg biomass o.6 3 X 10-4 1X 10-1 1 X 1()-2 Pinfish avg biomass 0.18 1 X 10-4 9 X 10-3 4 X 1(@-3 Crab max biomass 1.5 5X 1" 3 @< 10-1 6x 10-1 Brown shrimp max biomass 0.07 3X 10@-5 5 X 10-3 7X 10-4 Dry eight -I.r' to, animals were taken from liellier (1962), others were measured. Table 21 (Parker 1-962). Results of zinc analyses Sample N-ipticm Z" ppm. Bay water salinity 34.4% ;,, Aug. 18, 1960 0.008 Bay water salinity 14"o, Dec. 8,1960 0.006 Sediment upper 15 cin 10 to 18 Algae Digenia simplex 60 Algae Gracilaria sp. 89 Turtle grass Thalamia testudinunt 100 Thin grass Diplanthera wrightii 88 Alullet Magil cephalits 130 Pinfish Lagodon rhomboides 113 Silverside Menidia sp. 51 Killifish' Fundulus similis 29 Croaker Micropogon sp. 43 Brown shrimp Nnaeus aztecus 45 Grass shrimp Palento"netes sp. 70 Blue crab Callinectes sapidus 46 Clam Chione cancellata 9 Clam L@cinia floridana 25 Barnacle Balanus eburneas 36 a "'verage of 3 or more analyses eaeb. Tables 19-21. Chemical contents of the dominants of a turtle grass bed in Redfish Bay,.Texas (Parker, 1962; Parker, Gibbs, and Lawler, 1963). 47? ui -i ASPARTIC 0 AC I D 2 GLYCINE (00200- THREONINE X SERINE z GLUTAMIC W ACID -i D US QIOO - ALANINE W ISOLEUCINE z LEUCINE u D METHIONINE TYROSINE a W PHENYLALANINE -J. Q-7 VALINE (Z R-ALANINE 00 EFFLUENT 100 200 300 400 500 600 MI - - pH 3.25,02 N NoCITRATE PH 4.25,0.2 N No CITRATE Inn exchange ChTOmatogram of acidic and neutral amino acids. Sample: 15 liters of sea water f i om Redfish Bay, Texas. z;; 0.250- W 0 cr 0.200- W, 0.150- ACIDIC Ek -i NEUTRAL AMINO I < ACIDS 0 0.1 C)o - AMMONIA TYROSINE et W PHENYLALANINE I 0.050- LYSINE W NITHINE ARGININE HISTIDINE 0- EFFLUE N T 0 100 200 300 400 500 600 M1 @- PH 4.26,0.38N No CITRA7E . 1 - PH 6.5, Q.38 N No CITRATEA Ton exchange chromatograrn of basic amino acids. Sample: 15 liters of sea water from Red- fish Bay, Texas. Fig. 31. Amino acids in the waters among the grass blades of meadows of Redfish Bay, Texas (Park, 1963). LAN'NE J E L fG I@OLLE T I ME H ON L jq@P\ LVAINE LIGHT FOOT CANDLES RATE OF CHANK NO 01IL/Mill % SATURATION Me %/L a Mm DEPTH Icho 0\ ... . ......... .......... .... .... . . . . MN ID r 0 01. a o aq EA CD r X- 5. 0 0 ct CD aq 0 EA 63, Gq CD 0 10 C+ C) zi 0 C+ m P- c 4 0 --------------- 9 tr 0 C+ EO 0 Me 02/L co ED V 0 10 cc m 04 0 C6 0. im C+. ct It rra zr to aq C+ mu* lb 10-0 r NO O,/L 17 C+ C+ \0 I" @-j Ri- cr 04 (D 4ca t,4 (PA C40 log (A prn m tr 479 PART IV. ENERGY TRANSFER Metabolism-02 1957-1%1 mean 20 on Tout respiration Go 10 Gross photosynthesis L J -i@ Spring7dinnei is_, .it to Aniftlets '.risurrarg again 10.01 Most of latter animals ftese and Jones, 1963) Summer water level mintinum. large daily: range 4) in 02, pH, and T 5.0 E on 3%2 Blot crab migration through pass to gulf Shrimp migration %Simmors and Hoese, 1959N through pass to cult (tkip"d, 1963) 5.0. l' r-- 7 1 1 1 1 1 - Commercial products (H&ne and Jones, 1963) E Blue crab P k shrimp 0 Daytime. 5-20* (20-35') 5-20'- - temperature CLa Total ostracods E (1(ornicker, 1964) on 0 1958 E 1959 Z J F*M A M J Jy A S 0 N D .Month Seasonal changfs in photosynthesis, total respiration, and some principal .it,ocks. for a turtle gruse hed, Redfish 11@y, Port Arairlsas, Texas. Fig- 33- Seasonal diagram summarizing studies of productivity in Redfish Bay, Texas (Odum, 1967b). '60 - 504 M 40- so-M 20- Uptake of Zn65by Tholossic Uptake of Mn54 by Tholossi ,.a so S 10 E 3 - 60- Eaperimeron. CP G CL E C, 5 lu 40- 4- X T 0. 20- 0 7. M M 6. 5. M I M I 0 0 4- 0 20 40 60 80 40 0 .26 40 60 80 .2 6:00 PM 6:00 PM 3- Time elapsed (hr) Time elapsed (hr) M 0 59 22 >1 Uptake of Fe' by Thola-s'sio Uptake of No by Tholossia Experiment 1 6 6 40 o-Tholaisic I Water E Lo E .9 0 .8 5 30- CL -5 CL CL 0 4 20- .4 X X 3 .3:5 3 10 - 3C "8 essentially no uptake 2 01 0 20 .40 60 so 0 10 20 30 40 0--0 20 4@1 11 80 <6 6:00 PM 8:OOAM Hours elapsed Time. elapsed (hr) Time elapsed (hr) Duplicate experiments showing the uptake of Co-60 by Thalassia. Only experiment I shows Typical experiments showing the uptake of Zn-65, Nin-54, Fe-59 and Na-22 by Thalassia. the loss of activity by the water which was observed in both. - @Ml M@11 Co Fig. 34. Uptake of four radioactive tracers by turtIG grass (Parker, 1966). animals 481 3:0 0 g log CAR80AI GRASS per M2 1009 rates in Top cm 2 P I CX10 Mud g/m /day 100 4 5-, l-, WATE k\@R= 10 300 mg 0.5mg in animals GRASS 300mg Top cm ZINC 10--, Mud per M (PARKER) Fig. 35. Mineral cycliag diagrams for carbon and zinc in Texas turtle grass (Odum, 1963). I00 T T ------------- 75 T ------- ----- 60 80 - 40- ------ ------ 40 - --------S------------------------ 40 20 40 53 1 DAYS 20 40 55 Comparison of average accumulated beight D^Ys ,cni) for four marine sperniatophytes : T (Pitilassia) Comparison of average accumulated height 1.1 Wiolanthrro) ; R (Riftpia) ; S (Syringodium) to (cm) icr Thalassia (T) 2nd Dip;anthcra (D) to sea- increasing. salinity in a tent pe rature-control led tank. The Water and to incrcasiog salini[,, in outdoor concrete ponds. dot on a growth curve approximates the position at H;--ight in the seawater pond It3j, tA-c. lines) is sbown which height increase terminated. The salinity at that olliv to 100 cin. The salinity dt-crease after 40 days wa; I rijid !i'ne. time is indicated on the solid line. due to a 4-in, rain. SAiiliity is indicatt@d by the kig. 36. Growth of bottom plants as a function of salinity (McMillan and-Moseley, 1967). 45 W-,l -- -------- ------ ----------------- m 14 WEIGHT OF MYCELIA WEIGHT OF MYCELiA (IN MILLIGRAMS) (IN MILLIGRAMS) 0 5 W, z' a C, 00 Q) rA rt m0 t-h -ma C., U) t-h C0 lzn E: --j Z m th 0 rtm 0 1,-6 cr 0h Z; o rn 0 m 0 I'm ;D no. 03 co a. III 0 0 1,-0 :sn rt 03 ft It CL -ei n 0 mrt o E; :3 @l :r 9 E 04 rt 10 rt m N SYRINGODIUM filif. THALASSIA test. 483 5- K/j M D M D M D M D M MOMDMDMDM 5- ... ... ... ... X X X., .... ... ... X M B M B M B M B M 8 M B M B M B M-B M B Photosyntheserate der marinen Phaneroaamea Syringodium /iliformi8 und Thalamia testudinum aus dem karibischen Meer bei 30miniitigem Wechsel des Mediums. TNI: INfeerwasser, D; destilliertes Wasser, B: '&. KHCO.,-Lasung fo-0-0 Fig. 38. Comparign y!t@yjtgm plantcgrowih,in linittes w@erfdilurions were made wit d e water nta n ng ftweasr9onatet nee e or photosyntnes. (Hammer, 1968). so 60- 40- M- 100 8' -6'-0- @QX20 0 % Meerwasser Photo,3ratheseraten von Thalassia testudinum in ver. 3chiedenen Salzgehalten. 1: identisches Material; N: jeweils neues Material. Die Expositionszeiten betrugen 30 min pro Verdiinnungsstufe. Abszisse: wie Abb. 3. Ordinate: Photo@. syntheseraten Fig. 39. Decline of turtle grass photosynthesis with decreasing salinity (Hammer, 1968). Thalassia testudinum Blatt Matt 280C Mg 600 rd Wassergehall 70-72% 400 Wasseraufnahnw 72% d.rnax. 200 wassergehatt 0 10h 11h 12h 13h 14h Thalwsia te8tudinum: Geivichtaabnahme in Luft; Ge. wichtszunahrae in Wasser Fig. 40. Water uptake properties of leaves of turtle grass after exposure (Gessner, 1968). 484 shows the carbonate content of the diluting freshwater sharply affecting the ability of the plant tissue to maintain a net energy budget under stress of freshwater application. Gessner (1968) finds exposed Thalassia able to take up water rapidly due to epidermal adaptations (Fig. 40). Hypersaline conditions occur in South Florida (Fig. 21) as well as South Texas. Fuss (1967) found turtle grass growing faster than Diplanthera (Table 22), in running sea water tanks. Temperature Adaptations The generally poor ability of tropical animals to acclimate to temperature changes was established as early as 1914 by Mayer. The economy of functions achieved by not carrying temperature Adaptations may contribute to the ability to do other functions that maximize the success of species and associations where temperature regulation is already provided. Seasonal Patterns The pattern of seasofial variation in tropical meadow systems is most marked at the northernmost range The record of pbotosynthesis and respiration in a turtle grass bed in Texas is given in Fig. 33 as determined with diurnal oxygen measurements. Data on individual days have nearly a 10 fold range (Fig. 32) in activity from the cloudy dark short days of winter to the long sunny days of'summer. The total community activity as indicated by the respiration measurements (Fig. 33) stays closely in phase by movements of populations, by the effects of temperature in accelerating micro-organismic activities, and by the automatic dependence and consequent systems coupling of respiration to the accumulations of organic matter in the previous time period. Seasonal patterns in similar latitude but under more uniform light and temperature are given by Jones (1968) for Virginia Key neAr Miaml (Fig. 16-17)) showing some correlation of productivity and seasonal light pulse. Whereas spring flowering and fall fruiting of the turtle grass corresponds to period$ of photosynthetic maxima, reproduction in fungi is maximal at the Fall decline of the long season of higher energy input (Meyers, 1968; Fig. 12 Tropical Meadows under Disturbance The maps of McNulty (1961) for Biscayne Bay, Miami, Florida, show zones of bottom vegetation (Fig. 41) and associated animals at increasing distances from outfall of domestic sewage and other waters flowing out from shore.including ground water. Near the shore and outfall where nutrients are high, waters are colored, more turbid, and the bottom vegetation is mainly absent or has red algae adapted to shade. Diplanthera and HalophilA appear next; and Thalassia appears well awav from salinity and nutrient disturbance. For other properties see Chap. C-6 and E-1. As a result of dredging and release of turbid waters in Redfish Bay, Aransas Pass,Texas, the grass was killed when smounered 30 cm under silt, but was stimulated to greater growths in the remaining part of the year where the settling sediment did not bury the blades. See Chap. E-4, Table 3, which contrasts chlorophyll in bottom plants in relation to this disturbance. FIXED VEGETATION BENTHIC MICROFLORA RED ALGAE rHA4ASSIA SPERMATOPHYTES DOMINANTS 0 HALOPH11LA 4 D DIPLANTHERA PHYTOPLANKTON I'lW THALASSI A 6 jI I NO 8 - VEGETATI CL W 10 12- 100 500 500 GROSS PRODUCTION, mg 02/m2/hr Variation with depth of the relative primary production of the plant popwailulls in Boca Ciega Bay. Most of the bay is less than two meters deep. FIGURE 7. Horizontal Zonation of fixed vegetation. Fig. 42. Components of photosynthesis in an arm of Fig. 41. Bottom vegetation in Biscayne Bay, Florida Tampa Bay, Florida where grass is thin in the vicinity of sewage waste outfall (Pomeroy, 1960). OD (McNulty, 1961. 486 In Fig. 42 Pomeroy (1960) reports the partition of primary productivity between phytoplankton and sparse turtle grass and its epiphytes. System Competition and System Hybrids The benthic vegetation-system has means for competition with coral reef systems in those zones where both might otherwise grow. In Puerto Rico in relatively low energy areas, the benthic vegetation intermingles with corals-. The ability of the bottom vegetation to outgrow and shade out the coral polyps is balanced by influences of benthic urchins which derive protection from hard coral structure. In conditions intermediate between the high wave energy coral situations and the lower wave energy vegetation bottoms, some mutual organization produces combinations. Randall (1963a)showed that artificial reefs constructed in tropical meadows developed fish populations that moved out from the refugepcutting back the benthic vegetation in the near perimeter. This behavior may'be a case of the general role of higher consumers in concentrating on members of alternative community systems with the effect of being an agent in system competition. . When waters are deeper and more turbid the benthic vegetation becomes a minor subsystem of the plankton system above, but in shallow clear waters, the benthic system holds plankton components as minor stibsystems of its own predominant pattern. An example documenting the low productivity from the dilute grassy bottom under more turbid water is given by Pomeroy (1960) in Fig. 42. Van Breedveld (1966b) used submerged grass,.Syrl2godium, filiform) on toroato plants in Florida comparing its effects on growth and its chemical analysis with those of a brown alga. Table 23 shows analyses of the plants which accounts for their success as a fertilizer. Salt was no problem since it washed away in that particular climate. Anderson (196o) used data from the Texas turtle grass to estimate potential yields for agricultural uses. Overall Energy Budget Brylinsky (1967), working with R. J. Boyers, attempted computations of an energy flow for the turtle grass community in Texas with the results in Table 24. They are comparable to those of temperate zone Zostera beds worked out by Peterson (See Chapter C-7 and the diagram in Fig, 37 Research Needs Many questions are unanswered and require direct experiments. For the main classes of wastes from urban development, what is the total system response of the tropical meadows? Does plankton blooming develop and shade out the bottom system; is the benthic system stimulated or set back? How much simpli- fication takes place in the system that might channel food production? Which wastes, if-any, are compatable with high gross productions of tropical meadows? Table 22. Winter survival of sea grasses (Fuse 1967) -Seight and percentage of living sea 487 grasses recovered 6 and 8 months after planting in trays suspended in an open sea- water system Plant material Genus and lWet weight recovered planted period (9/1-3/65) Wet Percentage weight Thalassia: Ounces Ounces Percent 6 months .... 28.0 22.4 80 8 Mont .... 28.1 16.8 60 Di planthera: 6 months. 5.3 0.9 17 8 months.* 5.3 0.1 2 Table 23.Analyses of Syringodium used for fertilizing tomato plants (van Breedveld, 1966b). June, 1964 July, 1964@ Norwegian Ascophyllum Nitrogen, % 1.610 1.890 1.57 Phosphorus, % 0.857 0.676 0.21 Potassium, % 1.16 - 1.28 Iron, % 0.053 0.106 0.09 Copper, % 0.0032 0.00252 0.00635 Table 24. Summary of production and respiration for turtle grass community of Redfish Bay, Texas. F1:g.ures are expressed in kcal/M2 yr (Brylinsky, 1967). Trophic Level @@oduct.ion Respiration Producers 3076 Herbivores 370 Carnivores 1273 Detritivores 2491 Exportjnet prod.) 44 Total 8876 7254 488 Chapter B-4 TROPIrAL INSHORE PLUMON SYSTEM James A. YJarsh, Jr. Department of Environ ntal Sciences and Engineering University of North,Carolina Chapel Hill, North Carolina 27514 Chaxacteristic tropical inshore plankton associations occur in shallow waters along tropical and subtropical coasts where the ecosystem is not sub- jected to regular seasonal temperature pulses. With less controlling influence from seasonal factors more complicated biological interactions develop than in temperate systems. The chief energy inputs are light and organic matter from adjacent axeas, such as mangrove swamps. The waters are deep enough so that plankton predominates over bottom plants but shallow enough that the bottom is involved in the mineral cycle. Plankton comunities achieve maximim stability in certain small, shallow bays of dry regions where there is a notable lack of influence by tides, waves, or sudden runoff of fresh water. Each of these bays contains a discrete water mass with a slow renewal rate. The comminity achieves the steady state char- acteristic of an ecological climax. Tropical bays with indigenous plankton ,communities are rather uncommon in the United States and elsewhere. EXUAPLES Figure 1, taken from Yargalef U962),shows the ecosystems -in a gen- eralized cross section perpendicular to the southern coast of Puerto Rico. The deeper offshore waters have the characteristics of blue water coasts. Tx the shallower waters there is no vertical stratification and the waters are mixed all the way to the bottom. Nutrients and organisms are not perrp-nently lost from the euphotic zone. There is extensive exchange with the blue-water regions, and oceanic salinities prevail. However, there is a characteristic phytoplanktoonn community with Chaetoceras, Asterionella, and Thalassionema. In many of the enclosed and semi-enclosed bays salinities bldld up because of high evaporation rates and low fresh-water input. Nutrient levels are high and indigenous ecosystems develop. Figure 2 is a general map of the inshore waters of southwestern Puerto Rico and shows areas where tropical plankton communities have been studied. Bahfa Fosforesctnte A remarkable example of the stable plankton bays is Bahia Fosforesc6nte on the southern coast of Puerto Rico. This bay has a permanent bloom of the dinoflagellate Pyrodinium bahamense which is responsible for the brilliant bioluminescence of the bay every night of the year. Any disturbance in the 489 A B C Plancton de dinoflage- Evaporaci6n ladas Y Rhizosolenia en -neuston y larvas de aguas nils profundas animales bent6 ,nicos S 36 S hacia 36 S 36 -38 5, Al Substit@ici6n de las dia- tomeas por d;noflageladas en el agua mis tranquila Y concentrac-i6n de orga- nismos fototActicos que Agitaci6n del agua-hasta ilegan con el agua super- el fondo, conaumento de ficial. La vegetaci6p su capacidad productiva retiene organismos del Agua y desarro116 de diatom: eas agua que flu-.re @,acia fuera. m9s sa- nerfti6is (Chaetoceros, Notable reserva de ele men- lada y m;fs Asterionella, Thalassio- tos nutritivos en el fondo. nutritiva que se nema). desliza sobre el fon- do @@acia el exterior. Plankton composed of Neuston and larvae of tvappration. Salinity 36-38 ppt. dinoflagellates and benthic animals. Sal- Replacement of diatoms by dino- Rhizosolenia in the inity about 36 ppt. flagellates in the'quieter waters deeper waters. Salinity Circulation of water and concentration of the photo- 36 ppt. @bre saline all the way to the synthetic organisms which migrate and nutrient-rich bottom' increasin P g into the sui@fac6 waters. Vege- water sliding seaward the productive capa- tation- retains organisms from along the bottom. city and favoring the outflowing water. Prominent neritic diatoms reservoirs of nutrient elements (Chaetocerasi, in the bottom. Asterionella, Thalassionema). Fig. 1. T!ropical inshore areas in a generalized cross section perpendicular to the southwest coast of P@xerto Rico (From Margalef 1962; P- 392). 4W Lo MONA PA SSAG5, n ;,il a I., rM4 Uahfo ontal Ya @:i,: an ........... .. ..... .......P L.Pizanayu r- L.%,x: Magueyes OpUdjlm 1,1 Go d'. V* A� Sucia Gk'WEnPiqu@ It -Me @o "i" SE1 Ma C rr 90,6,w r1o El Laurel C@ QY El Atravesado Urr mote. 'QP0 Q? JO If % Media Luna oil rito to rg C % _75- AF(P U ........ LA ............................ .............. -20 00 .... . . ...... Land Mangrove CARIBBEAN SEA _01coral reel 14 Islet Bottom contours In fathoms lo, 00 -Southwest coast of Puerto Itico. showing region where plankton samples were colhxted. Fig. 2. Map of the southwest coast of Paerto Rico (From Gonza'lez and Bowman 1965). 491 water agitates these single-celled organisms and stimulates them to give off light; as long as they are undisturbed there is no biolurninescence. The wakes of boats, the outlines of swimmers, and the paths of frightened fishes are marked by the flashing displays of thousands of disturbed dinoflagellates. Often the lightmay be bright enough to read by. Even raindrops striking the water produce thousands of momentary flashes all over the bay. The bay rep- resents not only a pleasing esthetic experience for visitors with a sense of wonder but also a unique opportunity for ecologists to study climax in a natural plankton comminity,'a concept of widespread interest. Bioluminescence is co n in other temperate and tropical waters, but conditions favorable for this phenomenon are usually transitory and unpredictable. Physical conditions in BahD9. Fosforescdnte are rather. constant. Burkholder and Burkholder (1958) observed surface temperatures at various stations ranging from 28.50 to 30-50C in July. Values at these same stations in February averaged 3-40C lower. Bah:ra Fosforescente lies in a rain shadow and receives very little runoff from the surrounding land area. Such rain- fall as does occur is primarily seasonal. Because of low runoff and high evapo- ration rates salinities axe high. Coker and GonziLlez (1960) reported surface values ranging from 34.1 to 36.7 parts'per thousand. Values go higher in the upper fingers of the bay among the mangroves. Figure 3 shows salinities in a typicalvertical section obsel-ved by Margalef_(1962). Figure 4 shows the vertical section after a rain when a less saline tongue of water entered the bay at its surface and sank beneath the incoming waters at the mouth. Another significant factor is the relatively small exchange with the open sea. Tidal amplitudes are small, a third of a meter or less. There is only one tidal cycle per day. The mouth is shallow and is narrow in relation to the size of the bay. Exchange of water through the mouth is thus extremely res- tricted, and an ecological climax is maintained without physical interference. Coral reefs lying offshore further protect the bay by cutting down on wave and current action. There is little vertical stratification in the bay since it is shallow enough for continuous mixing. The average depth of Bahla Fosforesc4nte is 3-5 meters, and the maximum depth is about 4.5 m. There is oxygen all the way to the bottom, and the top part of the sediments is aerobic. Along with the physical constancy there is a characteristic set of chem- ical and biological factors. Most of Bah:ra Fosforesc6nte has a gray-green to brown coloration markedly different from the clear blue waters offshore. In shallow peripheral zones the waters are dark brown, probably because of man- grove peat on the bottom. Inorganic and organic nutrients are undoubtedly contributed from the surrounding watersheds during the rainy season. Because of its slow rate of water exchange the bay acts as a nutrient trap which main- tains 6 chaxacteristic set of chemical conditions. Organic nutrients build up beyond the levels ordinarily found in flushed estuaxies. Burkholder and Burkholder (1958) reported levels of Vitamin B12 in the suspended matter of Bahia FosforescLsnte ranging from 430 to 2930 m-r per gram of dried solids, higher than in waters outside the bay. (See Table I). These levels were also higher than in other estuarine ecosystems which have been studied. Values for dissolved B12 were 3.0 and 3.5 MT for 2 stations in the bay and 1.3 my @for a station outside the bay. 492 ZOO Metros 11 Julio 1958 ------- N 35, 4 m 8 M Fig. 3. Cross section of Bah:ra Fosforerc!5nte and adjoining waters outside of the bay, showing isohalines (From margalef 1962; P- 389). > 35,55 35 5 4 35,53 36 Fig. 4. Cross section of Bah:fa Fosforesc6nte shoving isohalines after fresh water runoff following a rain (From Margalef 1962; P. 391)- C35@ 493 Table 1. Vitamin Bip in suspended solids of Bahfa Fosforesc6nte. Stations 3A,,4A, 6A, and'10 are in the open waters of the bay. Station 7A is in the mouth, and Stations 8A and 9A axe in the waters outside the bay. Other stations are around the Lmxg:Lns of the bay (From Burkholder and Burkholder 1958). VITAMIN B@ IN SUSPENDED SOLIDS ASSAYED WITH E. coli. DATA ARE GIVEN IN My PER GRAM OF DRIED SOLIDS AND PER LITER OF WATER B. per gram B. per liter Station Depth in feet Surface Bottom Surface Bottom IA 1 947 847 7.3 7.3 2A 4 932 430 7.2 20.0 3A 4 1313 693 8.8 17.5 4A 12 1041 882 5.0 40.0 6A 12 1325 780 8.8 73.3 6 (muddy) 12 1690 1264 100.0 146.7 7A 12 891 588 5.3 36.7 8A 14 909 833 3.3 2.5 9A 12 1875 1667 2.5 2.5 10 13 1100 1099 14.7 86.7 13 6 2930 2400 40.0 40.0 16 8 1071 - 12.0 - 22 3 625 865 15.0 23.3 25 5 1010 940 10.3 23.3 26 5 954 910 @13.7 23.3 494 It is known that'dinoflagellates similar to those found in Bahla Fosforesc&nte require Vitamin B12 and thiamin, but the nutritional requirements of these specific dinoflagellates are not known. The Burkholders thought that syn- thesis of the B vitamins probably occurred at significant physiological levels within the bay itself but stated that vitamins were undoubtedly contri- buted from the surrounding watershed as well. They suggested that contribution from the fringing mngroves was likely. A characteristic phytoplankton commmity is found in Bah:ra Fosforesc6nte. There is a dominance of dinoflagellates, with diatoms playing a nuch less important role than in most estuaries. The dinoflagellate Pyrodinium bahamense (Fig- 5) is responsible for most of the bioluminescence. Other species of dinoflagellates commonly found in Bahfa Fosforesce-nte, though in lesser den- sities, axe Rjn2physis caudata, Peridinium ddivergens, P. oceanicum, and T-9 Ceratium furca. MELrgalef l7ib) listed a To_-@l -of 16 species of dinoflagellates species of diatoms found there. Burkholder, Burkholder, and Almod6var (1967) reported.that blooms of Cochlod'inium sp. sometimes occurred and gave a red color to the water in the upper armn at the western end of the bay. These blooms generally seemed to occur after heavy rains and were readily destroyed by motorboats passing through them. Chlorophyll a values in the open waters of the bay were 4.5 - 5.4 mg/m3 and reached 37 mg-in the Cochlodinium blooms (Fig. 6 and Table 8). While this bay may contain respectable standing crops of phytoplankton its primary productivity is not remarkably high. Burkholder et al. (196-7) used the carbon-14 technique and found an average of 45 mg-carbon/`m7/g (c/m3/hr) fixed in the open waters of Bahfa FosforescEnte, intermediate between the average of 5 mg in the nearby open sea and values ranging up to 900 mg in certain bloom situations in the surrounding waters. Cochlodinium blooms in the western arm of the bay had productivities ranging from 55 to 162 mg C/m3/hr (.Fig. 7; Table 2). Plankton samples from the bay enclosed in bottles showed increasing phytosynthesis with increasing light intensity up to 51,000 lux, the maximim intensity attainable in the experinental apparatus of Burkholder et al. (Fig. 9). Odul, Burkholder, and Rivero (1959) studied the primary pro- ductivity of Bah:ra Fosforesegnte and nearby areas using diurnal oxygen curves and light- and dark-bottle techniques. They reported that 24-hour respiration of bottle samples exceeded photosynthesis in most areas of the bay; this means that there had to be an import of organic matter, probably from the mangrove areas. Gross photosynthesis was reported as 1.40 g 02/m2'/day. Photosyn- thesis of the bay waters was relatively small in comparison to nearby coral reefs and turtle grass flats. Zooplankton d'oes not appear to be noticeably different from that of other estuarine types. Coker and GonzAlez (196o) reported after a year-long study of Bahfa Fosforesc6nte that copepods dominated the zooplankton. The pre- dominant species was found to be Acartia tonsa, the same species which is the most cormon in Long Island Sound. Other dominant species in Bah:fa Fosforesc;6nte were Oithona minuta, 0. simplex, and Paracalanus crassirostris. Coker and Gonz9lez thought that conditions were perhaps less favorable for zooplankton in the bay than in nearby waters. They noted the absence of any large predator species in the daytime plankton but reported that the large copepod Pseudodiaptomus comes out at night. They observed clear seasonal cycles only in 0. simplex and 495 CIO Fig. 5. Pyrodin bahamnse (From Clarke and Breslau 1960). CLOROMA A (MG/10) I COCIVITZ 043q@M I SAUNIDA 0 31,6 zA 0 0 a 2 IL 4 . ..... . ... .... 2 3S.4 4 X6 2M Not 4M 43 M3 a 3-4 2 M 4-9= A - M 37 RK Secciones a trav6s de to Bahia Fo9forescente y parte de las aguas a la misma en distintas fechas (rodeadas por eirculos, estaciones 35. 4*2, 43 y 84 do fig. 1 y del pequet.to mapa in cluidu ea la figura). A I& 6-rda, distribuci6n de temperaturas v salinidades. A la derecha, lstribuei6n --l-,rofila a y del cociente entre las (fensidades 6pticas a 431) y 665 milimicha, de los extractos acet6nicos. Fig. 6. cross section of Bah:ISM FosforescEinte and adjoining waters. Temp- erature and salinity distributions are on the left. On the right are shown chlorophyll a distribution and the distribution of the ratio of optical density at 430 millimicrons to O.D. at 665 milli- microns) for acetone extracts (From Margalef 1961b). .4 496 MODOUN DAMAMENSE CDOCOOKM P0LyjNX0j= Q A@OSTO 058 11"30 _8QAMAA 22 KEAMAQ CM5.40 EM40-OD =5-W CELLU Fig. 7. Cell numbers of two species of phytoplankters in Bah:ra Fosforesc6nte (From Margalef ig6lb). Table 2. Carbon assimilation by microplankton from Bahfa Fosforesc6nte (From Burkholder-and Burkholder 1958). CARBON AssiMMATION BY MICROPLANKTON. SURFACE SAMPLES FROM PHOSPHORESCENT. BAY IN A FLUORESCENT LIGHT INCUBATOR AT 51,000 Luw 1963 1964 Feb. 23 Apr,* 23 May I July 10 July 19 (mg C m@ hr-1) ,Center of Bay 30.5 65.0 42.0 28.6 61.5 West Arm - 54.9 - 182.1 77,3 Outside of Bay 5.5 5.2 6.7 6.8 5.4 497 Euterpina. Malticellular zooplankton were found to be less diverse than in a nearby bay and in the open water over a r-edf. Table 3 shows the relativ6 abundance of different zooplankters in the6e 3 areas. Burkholder and Burkholder (1958) reported an abundant protozoan 'population but did not give species. The ecological role of fishes ih.Bah:la Fosforesc6nte has not been eval- uated. Jenkinsia. is reported to be abundant, and the paths of light it leaves when fleeing fr tourist boats contributes to the esthetic value of the bay. Other forms present are mullets, halfbeaks, and porgies. Fig. 8 shows moll usc data for the Bay. The high bacterial activity of the sediments is a noteworthy feature. Because there is little vertical stratification in the water, the surface of the bottom muds is aerobic at all times, but a naerobic conditions exist a few centimeters below the surface.. Bacterial activity is high both on the surface and in the anaerobic layers. This'undoubtedly contributes to the high levels of B vitamins and inorganic nutrients in the water. Burkholder and Burkholder (1958) found the highest B12 values in sediments collected from the margins of..the bay, especially in,the northern areas. They thought that this might be.related to microbial activity In decomposing mangrove materials. Aerobic bacteria ranged from 55 to 2400 millions of cells per gram of dried mud. Counts of aerobic and anaerobic bacteria are shown in Table 4. Margalef (1961b) :reported pigment values in the sediments of about 2 mg chlorophyll.a + b per 100,g. While light intensity at the surface of the bay is high, up to 130,000 lux, light extin6tion.in the waters,israpid. Coker and Gonzfilez (1960)'reported .that a 20@-cm Secchi disc disappeared at depths ranging from 1.75 to 3.9 m, i@xcept for 1 reading of 4.1 m occurring after a heavy rainfall. The Secchi disc always disappeared before reaching the bottom in the open waters of the bay. This is consistent with the finding of,Almod-ovar and Blomquist (1959) that Thalassia, does not grow at depths greater than 2 m. in Bah:ra Fosforese6nte. Burkholder and Burkholder (1@58),reported that suspended matter was greater.nea,r the bottom than at the surface (table 5) ai2d increased after a windy period. The winter average (11.2 mg/liter) was higher than the surmer average (7.4 mg/1). Suspended matter was composed mostly of plankton. Values were higher in.the bay than in the waters outside. They were in the same range as values for Long Island Sound during the spring bloom but lower than figures from waters around Sapelo Island during a bloom- (See Fig. 10.) Other Puerto Rican Bays Other bioluminescent bays in Puerto Rico are Bah:fa @bnsio Jos6 (Fig. 11), also on the southern 'coast, and Ca-no Hondo on Vieques Island. These bays h@ve not been as extensively studied as Bah:ra Fosforesc6nte, but physical conditions and biological characteristics are probably similar. Caffo Hondo does not lie in a rain shadow but is nevertheless in a very dry region. Bahfa Monsio Josd is the largest of the Puerto Rican bays and has an area of approximately 0.65 hectare. Oyster Bay, Jamaica Another example which has been studied is the luminescent Oyster Bay in 498 Table 3. Relative abundance of different zooplankters in waters of Southwestern Paerto Rico (F'rom Coker and GonzAlez 1960). Differential distribution by depth for leading sooplanktars, showing, for surface and deep at each station, number of collections in which found. mean of perpentages for 12 monthly collections, Novem. ber 1957, to October 1958, and standard deviation of the mean (S.E.) Rabia Foslorescente Montalva. Day 066110FS Species Depth No. Col. Mean % S.E. No. Col. Mean % S.E. No. Col. Mean% S.r. Copepods vs. Other Surface 12 74.32 5.63 12 62.98 4.55 12 64.77 5.00 Zooplankton Deep 12 78.35 3.81 12 07.28 3.57 12 62.12 3.41 Oithona minuta Surface 12 22.60 2.22 12 12.42 2.58 12 6.97 1.16 Deep 12 18.76 2.25 12 8.88 1.06 12 5.08 0.83 Acartia (onaa Surface 12 23.43 3.60 8 2.27 0.97 6 0.31 0.12 Deup 12 10.92 2.08 11 2.33 0,77 1 0.(YJ 0.02 Paracalanz;8 crassirostris Surface 12 12. A) 2.48 12 22.07 5.12 12 20.99 4.77 Deep 12 10.69 3.09 12 21.28 3.66 12 28.08 3.36 0. simplex Surface 11 8.30 2.91 12 12.69 1.77 12 8.02 1..56 Deep 11 7.21 2. 18 12 11.83 2.78 12 20.92 3X Euterpina acutifrons Surface 9 0.675 0.19 8 2.08 0.86 11 1.61 0.42 Deep 9 1.03 0.34 10 2.86 1.13 11 2.40 0.55 A. spinata Surface 3 0.10 0.05 10 1.82 0.75 9 1.18 0,35 Deq) 3 0.25 0.22 11 3.01 1.71 6 1.39 0.79 0.naaa Surface 3 0.20 0.13 8 1.62 0.143 12 3.15 0.63 Duel) 2 0.05 0.03 10 2.16 1.03 12 2.83 1.04 P. parvu8 Surface 3 0.10 0.06 0 .1.28 0.33 12 11.93 3.33 Deep 3 0.19-'0A7 7 0.95 0.61 12 3.70 1.42 Larvaces Surface 12 12.92 3.95 12 6.32 1.73 12 11.52 2.99 Deep 12 9.74 1.77 12 5.56 1.55 12 7.05 IA Univalve veligers Surface 12 8.52 1.75 12 21.46 3.23 12 11.97 2.81 Deep 12 8.32 2.55 12 15.75 2.66 12 13.83 3.03 Bivalve veligere Surface 12 1.78 0.42 12 5.09 1.20 12 3.89 0A Deep 9 1.08 0.36 11 3.86 0.80 11 10.38 2.08 Chaetognaths Surface 3 0.25 0.17 9 0.60 0.21 1@ 1.20 0.23 Deep 2 0.06 0.04 6 0.17 0.67 9 0.47 0.16 Juvenile calanoids Surface 12 13.84 1.87 12 21.02 3.23 12 17.30 1.63 Deep 12 @4.98 4.30 12 18.35 2. 4 7; 12 13.70 1.71 Juvenile cyclopoids Surface 12 4.70 0.87 12 5.72 1.08 12 8.55 1.42. Deep 12 9.84 i.91 12 7.13 1.16 12 10.98 1.87 Juvenile harpacticoids Surface 9 0.91 0.33 8 0.82 0.31 11 1.34 0.63 Deep, 6 0.71 0.28 6 0.95 0. 3@ 11 2. 32 6.4@ Nsuplii, copepod Surface 12 12.68 @.Oi 12 14.86 3.26 it 8.61S 1.64 Deep 12 15.21 1.99 12 18.48 4.S6 12 6.56 1.30 499 9 7 6 6 u 3 Anomalocardia brasiliana. @hell morphology and position in the substrate. 2 20 23 1. Tzw"Om -C' LT, vs. temperature curves under stagnant conaitions for Lima scabrj a , Aequipecten irra dians Modiolits Ynodiolds 0 , Mytilas edidis 7/ Phacoides pectinatus +, Crassostrea rhizophorae 0 lJognomon alanis * , Br(i@hidonles recurivis a . Bra, chidontes extishis X. Brachidontes demissus[-- NUMBER oF =IVIDUALS 0 5 10 0 5 0 CRASSOSTREA ISOGNOMON BRACRIDMZS ld!!ZDPHC)Ft&E S&T-U-S RVCURVUS 100 so z .0 ;C10 - 60 15 - 211 20 0 iL 35 5 25 :3 Relative levels of all live individuals of the bra*. A Mortality-temperature curves for Lima sca- three species indicated, observed in a period of 80 min. nomalocardia brasilhina Vr, Brachidontes re- qurvus 0 , Phacoides peclindlusAL, and Brachidowes in Bahia Fosforescente. Zero indicates watcr-level at exustus * , Exposure time to indicated temperature timC ()f survey. *qs 2Q minutes, Fig. 8- observations on bivalve mOllUScs from Bahia Fosforescg.nte. I LT F 50 is the time.for 50 percent of a population to die (From Read 60" 1964). 500 Table 4. Numbers of aerobic and anaerobic bacteria in bottom deposits of Bahia Fosforesc6nte (From Burkholder and Burkholder 1958). QUANTITATIVE OCCURR:-:NCE OF AEROBIC AND ANAEROBIC BACTERIA IN BOTTOm DEPOSITS OF BAHIA FOSFORESCENTE. DATA ARE ExPRESSED IN MILLIONS PER ML Station Aerobic Anaerobic 10 55 - 32 6j 10 25 70 18 19 137 .9 31 171 - 9 229 133 3 236 - 23 274 - 11 455 346 22 -885 380 13 995 - 28 2440 Table 5. Dry weights of suspended solids in Bahia Fosforesc6nte. Station locations are explained in Table 1 (From Burkholder and Burkholder 1958). DRY WEIGHTS OF SUSPENDED SOLIDS OBTAINED FROM A SERIES OF STATIONS IN BAHIA FOSFORESCENTE. VALUES ARE ExPRESSED AS MG. PEP LITER OF WATER February Samples July Samp@es Station Surface Bottom Surface Bottom IA 8.7 8.7 2A 7.4 46.5 3A 6.7 35.3 - - 4A 4.8 45.3 5.6 7.3 5A 7.4 10.7 6A 6.7 93.5 - - 6 (muddy) 59.2 116.0 8.6 8.3 7A 6. 1 45.2 - - 8A 3.6 3.0 - 9A 1.3 1.5 2.0 10 13.3 79.7 - - 12 - - 8.9 10.9 13 13.7 16.7 - - 14 - - 6.3 9.9 16 11.2 35.5 7- - 22 23.8 27.0 - - 23 - - 7.9 7.9 25 10.2 24.5 - - 26 14.3 25.7 11.9 28.4 501 900" A 600- 700 B GOO. at 500- 12400- 300- C 200 ................... E 100 *10 F 0 5 10 15 20 25 30 35 40 45 so KlLoLux Carbon assimilation by blooms of microplankton in the neritic waters near La Parguera, Puerto Rico.-A, Goniodoma sp. bloom at the fish pen, Magueyes Island. Feb. 21, 1963.-B, Goniodoma sp. bloom at the eastern end of Magueyes Island, Feb. 19, 1963.--C, Ciliates from the @icinity df sea anemones at La Gata Island, Apr. 24, 1963.-D, Dinoflagellates in a bed of Thdassia, at La Gata Island, May 1, 1963.-E, Cochlodinitun sp. in the western arm of Phosphorescent Bay, July 10, 1964.-F, Mixed plankton in the center of Phosphorescent Bay, Apr. 23, 1963. Fig. 9. Carbon assimilation by microplankton in the waters of the southwestern coast of Puerto Rico (From Burkholder, Burk- holder, and Almod6var 1967)- 502 PERCENTAGE OF SURFACE LIGHT 10 20 50 100 I I 1 0 0 0 0 FO C? A -5 -10 M z M --I -15 rn -20 25 -Transparency measurements (F) in Phosphorescent Bay, (A) outside at Station A, Feb. 7, 1959, both near noon, bright sun, cumulus clouds, ce 2; and (B) outside reefs at Station B, Feb. 8, 1959, 1400 hrs, bright sun, clouds, wind force 4. Fig. 10. Water transparency in Bah:ra Fosforescignte and nearby waters (From Clarke and Breslau 1960). 503 t I- DE LA C-- 7: L-D ES M Monsio Jos( Bay and Posa de Don Eulalio Fig. 11. Bahfa Monsio Jos6 (From Coker"and Gonz9lez 1960). AWAS) X )k. ...... ..... AN@ -Z C' 0.5. ...... .... C 2. A 29 L.MOUT ARBOR .................... 6E- ....... SWAMP IE R X .........3 77-139' 138' General topography and location of hydrographic stations, Oyster Bay, Falmouth Harbor, Jamaica, West Indies. Approximate limits of brilliant bioluminescence shown with fine stippling. Fig. Topography of Oyster Bay (From Taylor, Seliger, Fastie, and wElroy l966). 504 Falmouth Harbor, janEL�-ca. its average depth is l.m, and the maximum depth is 2 m (Fig-12). The bioluminescent area is separated from the rest of the harbor by a shallow sill. The area is approximately 100 ha. Inorganic nutrients such as iron and phosphate achieve comparatively high levels, with the iron existing in particulate matter. Taylor, Seliger, Fastie,,-and WElroy (1966) reported inorganic phosphate values for Oyster Bay of 0.5 - 1.3 micromoles per liter and total phosphorous values of 0.8 - 5.7 micromoles per liter. They found iron concentrations of 1.2 - 11.6 micro- moles per liter. The most noteworthy feature about Oyster Bay is the periodic input of fresh water whicfiit receives from the Martha Brae River, especially after the rather frequent rains. This water spreads out as a layer on the surface and mixes very slowly@,_'Yith the characteristic bay water. Figurel3 shows the distribution of surface salinity after two days' rain. Figurel4 shows a ver- tical profile of temperature and salinity both before and after the rain. It is interesting that the bottom waters were about 10 C warmer than the mid-depth waters after the rain. Taylor et al. suggested that this might be due to absorption of solar radiation bTsuspended matter just above the bottom. Figures 15 and 3.( pe , show transects of salinity and tem rature across the bay after a rain. Tables6 and 7 show cell counts for different phytoplankton species at different stations in Falmouth Harbor, as reported by Taylor et al. Cell densities of up to 200,000 individuals per liter were recorded for Pyrodini bahamense. After a rainfall stations outside the Oyster Bay sill had relatively high densities of dinoflagellates which had been washed from the bay. Taylor et al. were not sure whether the bay acts as a basin which maintains a slowly Teproducing population for a long time or whether it constitutes an environment where rapidly reproducing populations are in equilibrium with the loss of organ- isms from the bays. They described the diatom populations in the river mouth as a "typical polluted stream" type which became dispersed in the bay'(Table 7). The river flows through a rich valley of sugar and banana plantations. Taylor et al. also observed a diurnal vertical migration in the dino- flagellates. Organisms in the bay moved into the surface layer at night and returned to the lower depths during the day, but there was no movement into the layer of fresh water lying on the surface after the rain (Tables 6 and 8). They also reported a diurnal rhythm of light production. Stimulated luminescence was observed only during the night-time hours, even after the organisms had been kept in constant light for a period of time (Fig. 17). Carbon-14 productivity values in the b were consistent with values obtained for Bah:ra FosforescEnte, 11-27 Mg CrJ/hr for samples dominated by dinoflagellates and 87 mg C in a surface sample dominated by an unidentified small diatom. Other Paerto Rican Waters Information about other insh ore areas comes from Yexgalef (1957, 1961b, 1962), and a few' data about these areas have also been included for comparative purposes in bioluminescent bay studies. Margalef (lqbl@ reported yearly temper- 505 N 44, 15 10 5 ;IWO 100 0 METERS Surface salinity Falmouth Harbor, Jamaica, 2z January ro6r. Fig. 13. Surface salinity in Oyster Bay after two aays@rain (From Taylor et al, 1966). 8ALINITY Ma) 10 20 30 W W Us 2 24 25 26 27 28 29 3 0 TEMPERATURE VC) Vertical distribution of salinity (open circles) and temperature (solid circl") at St. B, .Falmouth Harbor, Jamaica, showing homogeneity' on ig January z96i (broken line) and stratification on zz January iq@i (solid line). Fig. 14. Vertical distribution of salinity and temperature in Oyster Bay both before and after a rain. See Fig-12 for -lociition of Station B (From Taylor et al, l966). 0- 2-- 506 5- 20. W 25 30 z 3 500 METERS F E E' E" 8 B to 4 5 0 25 34 z 'Iy *41-@","-' 500 METERS 0 C, C A Salinity distribution Moo), Oyster Bay, Falmouth Harbor, Jamaica, zi January iq6i; top: a section from mouth of Martha Brae River to north shore; bottom: a section from open harbor to head of bay. Fig. 15. Cross sections Showing salinity distribution in Oyster Bay arTer a rain (From Taylor et al 1966). 0- 5@ @77:728 2- 500 METERS F E E' E" B 0' 2 6 27 30 2 500 METERS C. A Temperature distribution ('C), Oyster Day, Falmouth Harbor, Jamaica, 2z January j 96 j top: & section from mouth of Martha Brae River to north shorej bottom: a sectidn from open harbor *to head of bay. Fig- 16. Cross sections showing tempera ture distribution in Oyster Bay after a rain (From Taylor et al 1966). 507 Table 6. Plankton in Oyster Bay when no fresh water layer was lying on the surface. Location of Station B is shown in Fig. 6 (From Taylor et al 1966). Dinoflagellates and diatoms in plankton at St. B, Oyster Bay, Falmouth Harbor, Jamaica, W. 1., 19 January 1961. Cells/liter. r-2115-----% /-2230 Surface I Meter Surface I Meter Surface I Meter Dinoflagellates Prorocentrum micans ............................. - 1,100 - 600 - 500 Dinophysis caudata ............................... 600 2,860 7,200 11,000 14,000 5,600 Pyrodinium bahamense ............................ 102,000 156,000 219,000 134,000 190,000 129AM Peiidinium breve ................................ I - 1,800 2,400 1,700 4,400 1,100 Peridinium divergem ............................. 1,800 2,200 7,200 1,400 8,906 1,700 Ceratium hircus .................................. 2,900 6,700 6,700 8,300 11,000 3,300 Ceratiumfusus .................................. - - 6,700 600 5,600 - Ceralium sp ..................................... - 1,100 - - 1,100 Diatoms Gyrosigma (Pleurosigma?) sp . ...................... 600 - - Nitzmhia closterium .............................. - 600 - 500 Nitzschia sp ..................................... 600 - 1,100 - 1,100 Unident. small centrales .......................... 14,000 10P000 12,000 14,000 22,000 11,000 Table 7. Plankton in Oyster Bay after a rain. Station locations axe shown in Fig. 12 (From Taylor et al 1966). Dinoflagellates and diatoms in plankton at Sts. B, D, and F in Falmouth Harbor 22 January 1961. Cdh/lit'cr. Station B r- Station D ---,N Station F r 0900--------% t-1230------N t-1500------N r- 1100 1130 Surface I Meter Surface I Meter Surface I Meter Surface I Meter Surface Dinofiagellates Dino ,physis caudata ............. 3,300 6,700 1,200 7,400 3,300 5,800 2,200 37,000 1,100 P 0 000 148,000 4,400 102,000 - yrodinium bahamme .......... 17,000 128,000 24,00 156, 45,000 Peridinium brevt ............... 3,300 1,100 600 2,500 1,100 1,200 i'100 3,400 - Peridinizim divergens ........... - 8,900 2,400 7,400 3,300 8,600 1,100 2,300 - Ceratium hircw ........ ....... 1,700 5,600 1,200 7,400 2,200 4,600 4,400 26,000 - Ceratiumfusw ................ - - - - - - - 2,300 - Unidentified flagellate ......... - - - - 2,200 Diatoms Mekjira sp . .................. - - - 2,300 - Rhizosolemia sp ................. - - - - 1,100 L),como phora sp ................ - - - - - 3,3W. Na%dcula sp ................... - 4,600 7,400 3,300 ]AM - 54AM Gyrosigma (Pleurvf@@?) Bp. - 3,300 Nitzschia closterium ............ 1,7W 1,200 5,000 2,200 1,200 1,100 1,200 12AW Nitzschia sp ................... 8,300 2,400 10,000 5,500 1,200 1,100 3,500 17,100 Unident. small centrales ........ 608,000 52,000 18,000 96,000 1,200 - 3,W - Unident. small permales ........ - 600 - - - 13,006 508 -13 - 13 600 -12 % 600 M ELr_<!d_i_n_1_uH! - 12 0 Biolu-inelocence 0 PY 111.1-iin-e@l Soo 10 Z ;Z, 9 9 __';'400 8 400 8 7 7 300 6 300 6 5 U 4 _'200 4 o200 3 3 o 100 2 100 0 0 _L L I L I I I 1 0 LL L L LI L 0 190.0 L 00 0 00 600 2.2.. . :1 0400 0700 1000 1300 1 .0 to, 0 1 .`,1 Ti- f Dity 7. i- f MY Variations in bioluminescence intensity Variations in bioluminescence intensity and number of Pyrodinium bahamense cells at 30- and number of Pyrodinitim bahamense cells at W cm depth, with time of day, at Oyster Bay, Ja- cm depth, with time of day at Oyster Bay, Jamaica, maica, West Indies (Niarch 1965). West Indies (.\larch 1965). Fig. 17- Variations in bioluminescence intensity and cell numbers with time of day in Oyster Bay (From soli 1966). Table 8'. Carbon assimilation and chlorophyll a In waters of southwestern Puerto Rico (From Burkholder et al 1-967)- CAR13ON FIXATION AT 3 1,000 Lux, CHLoROPHYLLa, AND ASSIMILATION NUMBERS (A/B) FOR SOME NERITIc BLOOMS OF PHYTOPLANKTON IN SOUTHERN PUERTO Rico Chlorophyll a Organism Date' Location A B A/B (mg C m-1 hr-') (mg m') Goniodoina Feb. 18 W. Magueyes 414 - 28 W. 380 166.0 2.3 28 E. 289 142.0 2.0 28 W, (Sunlight) 177 48.1 3.7 Peridinium Apr. 23 Guayacin 900 69.0 13.0 May 1 11 50 8.0 6.2 1. 1 to 63 10.0 6.3 to .1 2 11 114 [email protected] 4A 1. 2 84 21.0 4.0 July 9 440 79.0 5.6 Apr. 29 Offshore 4 0.4 10.0 May 1 01 .7 1.1 6.*4 July 12 It 5 6.6 8.3 Dinoflagellates Feb. 23 Phosphorescent Bay 31 4.4 7.0 Apr. 23 1. 43 4.4 9.8 July 10 20 4.0. 7.5 11 11 19 62 5.4 11.5 Cochlodinium 11 10 182 37.0 19 77 7.0 11.0 Ciliates Apr. 24 Anemone, La Gata 290 268 j.4 Diatoms etc. Apr. 29 Guayaca'n 2@O 60.0 3.7 Dimaliella July 10 Salina Fortuna np 56.0 - Ciliates Feb. 26 Briaretim, La Gata 60 60.0 1.0 Green flagellates May 19 Salina Parguera. 337 All "tes 1963 except July which is 1964. 509 ature variations at Yngueyes Island of 26.7 - 32-20C. Burkholder and Burkholder (1958) observed a February temperature of 25.1 and a July temperature of 28.1 at a station just outside Bah:ra Fosforesc6nte. Rainfall in the whole region is low, about 30 inches annually; and evaporation is high. Surface water flows from offshore in the direction of increasing salinity in the upper bays (Fig. 1). Mqxgalef considered that steep vertical isohalines (Fig. 20) are indicative of a'stronger flow than are the almost horizontal isohalines sometimes observed (Fig. 3). The general current in the region flows from east to west. Margalef (1961b,i962) also viewed the hydrography and plankton distribution in the whole region as being in a quasi steady state, at least in the summer. He regarded the successive types of plankton commmities in a transect proceeding from offshore to the small bays as the stages in an ecological succession (Fig. 1), with the bioluminescent bays representing the climax type. Light penetration in other inshore areas is greater than in the bio- luminescent bays; Burkholder and Burkholder (1958) ;reported that the Secchi disc disappeaxed at approximately 5.5 m in July at their station just out- side Bahia Fosforescente. Dry weights of suspended solids ranged from 1-3 to 3.6 mg/i (Table 5). Vitamin B12 in suspended solids ranged from 833 to 1875 m'fper gram (Table 1). Phytoplankton in the waters coming from offshore contains many pelagic forms (Fig. 1). Blooms of various species occur very commonl but at irregular intervals in the inshore waters. Burkholder'et al. studied 14C productivity - in- protected areas of brown in blooms of flagellates, ciliates, and diatoms water and reported photosynthetic activity at 51,000 lux ranging up to 900 mg C/m3/hr (Figs.9 andI8 ). This was in contrast to offshore blue waters with productivities of 4-7 mg C/m3/hrl. Chloroph;yll a values ranged from 8 to 208 mg/m3 in the brown waters and 0. 4 - 1. 1 mg/m5 off shore (_%ble 8, F ig. 21). Samples of Goniodona and Peridinium blooms showed increasing C amlynii-ation with In- creasing ligbt in ensities, even up to the full-sunlight intensity of 130,000 lux (Fig,.19), There was thus no inhibition of photosynthesis at higher in- tensities. According to Coker and Gonzfilez (1960) the zooplankton has a greater diversity in nearby waters than in Bah:fa Fosforesc6nte itself, and conditions are perhaps more favorable for zooplankton in these other waters. There is also less dominance by copepods here. Tables3 and 9 show relative abundance of zooplankton species at inshore localities. Other Inshore Areas Other areas which@might be classified as having tropical inshore plankton communities have been very poorly studied. Eastern Whitewater Bay and adjacent Coot Bay in Florida's Everglades form a body of water which is not biolu-Mines- cent but which appears to be similax to the Puerto Rican bays in certain res- pects. According to a reference by Tabb and.Yokel (1968), there is apparently a single water mass which is stable on a day-to-day basis and has a restricted mixing with adjacent waters. The.seasonal salinity program may have values ranging from 5 to 30 ppt, depending upon fresh water inflow from the Everglades. U) 0 W 900- 100 - A z 080- 700 BOA F_ 0 600 2: 500 jL 60- 0 400- 40- 0 300. 2 zoo. D _j 20- E W 100 G: ..................... A a a 6 0 -6 0 0 20 40 80 so 100 120 140 0 5 10 15 20 25 30 35 40 45 so KILOLUX KILOLUX Carbon assimilation by diverse blooms of m1croplaakton in tk Relative carbon assimilation by Goniodoma sp. (solid circles) A neritic waters near La Parguera, Puerto Rico.-A, Peridinium sp. bloom a- the fish pen, Magueyes Island, Feb. 28, 1963, and Peridinium sp. (open circla4 Guayacin, Apr. 23, 1963.-D, Peridinium sp. bloom at Guayacin, May I at Guayacin, May 6, 1963, in relation to increasing intensity of natural dayligh@' 1963.-C Peridinium sp. bloom at Guayacin, July 9, 1964.-D, Diatom! in southern Puerto Rico. The maximum values observed (at the highest int*1 dinoflagelilles and Chlainydomonas sp. in Guayacin Channel, Apr. 29, 196., sity) in each experiment are taken as 100 per cent, and the other values ale,, @E, Euglenoids and dinoflagellates at Guayacin, Apr. 22, 1963. expressed as a percentage of these maxima. Fig. 18. Carbon assimilation by microplankton in the Fig. 19. Relative carbon assimila-rion in relation to waters of the southwestern coast of Puerto natural daylight intensity in the waters of Riccr (From Burkholder et RI 1967) the southwestern coast of Paerto Rico (From Burkholder et S1 1967)- 0 0 511 17 Julio 19 5 a 200 m apro3drnadaniente N Eulalio Monsio loss 3 O(Z' 36/5 _*_@9 3 2 A rn ,7/7/727777, ?/- do 37 Fig. 20. Isohalines in a cross section ox the waters ofsouthwestern Puerto Rico. See Fig. 2 for location (From Margalef 1962; p. 389). CLOAOFILA A-8 ME" SUPERFICIE 2KM TOTAL MGM' amo.5 05- 1 Fig. 21. Distribution of chlorophylls a and b in the waters of the south- western coast of Puerto Rico TFrom Rargalef i961b). Table 9. Copepods in Bah:ra Fosforesc6nte (From Coker and Gonz6.lez 1960). Alature copepods occurring at any station in as much as one-fourth of the collections or making a@ much as 0.5% of total copepods, giving, for each station, number of colections in which found (maximum is 24); mean percentage to nearest 0.1; standard error of the mean; and rank in-percentage; "X" Big. nifics: observed in collection, but not appearing in count.* Fosforescente Montalva Offshore No. of S.E. No. of No. of Col. Alean % Col. Mean % S.E. Col. Mean % S. E. Oilhona minuta ............. 24 20.7 2.34 1 24 10.6 2 29 3 24 6.0 1.01 4 Acartia tonsa .............. 24 17.2 3.00 2 19 2.3 0 88 6 T 0.2 0.86 12 Paracalanus crassiro8fris ... 24 11.4 2.80 3 24 21.7 4.45 1 24 27.5 4.13 1 Oilhona simplex ............. 21 7.7 2.57 4 24 12.3 2.32 2 @24 14.5 2.73 2 Euterpina acutifrons ....... IS 0.9 0.28 5 18 2.5 1.00 5 22 2.0 0.49 6 Acartia spinafa ............ 6 0.2 0.17 6 21 2.7 1.32 4 15 1.3 0.60 7 Oithonanana .............. 5 0.2 0.09 7 18 1.9 0.82 7 13 3.0 0.86 5 Paracalamus parvus ........ 6 0.1 0.13 8 If) 1.1 0.49 8 24 7.8 2.56 3 Acartia 1111jeborgi ........... 6 0.1 0.05 9 9 0.2 0.10 10 10 0.4 0.16 11 Coryeacua amazonicus ...... 3 10 7 0.2 0.09 11 18 0.8 0.17 9 Corycaeus anzert .canus ...... '0 7 0.1 0.04 12 IS 0.9 0.29 8 Temora furbinata .......... 1 10 0.3 0.11 9 16 0.5 0.11 10 Centropages furcatu8 ....... 0 X 1 8 0.1 0.05 13 Immature copepods made 41.4'70 of copepods. for Fosforescente, 43.81:@, for Montalva, 34.80,7o for Offshore. However, there is no sudden runoff@from adjacent areas, and tidal exchange is minimal. The average depth is slightly more than a meter. The open waters of the bay grade into broad mangrove areas in the upper reaches. There is apparently an indigenous phytoplankton community dominated by small-celled'diatomr., although species determinations and their relative abundances have not bee 'n published. Further information about Whitewater Bay would be useful in giving it a desig- nation in the estuarine classification system. Even less is known about most other bodies of water in southern Florida, and it is not clear whether they should be classified as having tropical inshore plankton communities. Davis and Williams (1950) did a survey of the plankton of mangrove areas in southern and western Florida. They considered these areas as being subject to strong seasonal patterns, though there was no seasonal study made of the plankton. They regarded most or all of these estuaries as well flushed by the tides; this would inhibit the development of an indigenous planktonic community in a given body of water. Salinities were extremely variable from one area to the next and were undoubtedly strongly influenced by fresh water runoff through the Everglades. There was a marked absence of dinoflagellates from the phytoplankton and of coelenterates, platyhelminths, and chaetognaths from the zooplankton. Much more research needs to be done on the plankton in these waters and on the possible seasonal cycles before borderline cases here can be resolved to fit into the classification. There may well be other communities in areas of Florida and Hawaii which should be classified as tropical inshore plankton types. DISTURBANCE Because of their intricate balance of physical, chemical, and biological factors the bioluminsecent bays appear to be particularly susceptible to man- made disturbances.- One of the most important considerations is that these ecosystems are apparently adapted to low water exchange with the'open sea. The bioluminescence of a bay on New Providence Island, Bahamas, was completely and immediately destroyed when its channel to the sea was widened and deepened to make it more accessible for small boats. The bioluminescence of Bahfa Monsio Jose' is reported to have declined markedly since a small canal was dug connecting it to the sea and opening up another channel for water exchange.. It seems. clear that further alterations of this type must not be made if bioluminescent bays are to be preserved. Since the bioluminescence is dependent on a single species, P@rodin bahamense, the balance in these bays is particularly delicate. The exact ecological niche of this species is not known. Small changes in the quality or quantity of input from surrounding areas could easily,favor some other species and cause the bioluminescencAs to be lost. Hence, it is necessary to consider the maintenance of the watersheds and mangrove fringes around the bays as well as the bays themselves. Qualitative changes in the input through the mouths could also have a marked effect in the long run. Because of their slow flushing rates these bays could act as traps for substances which might lead to an alteration of the natural comminities. Of 5t3 course, Oyster Bay in J=@Ica is currently receiving a certain amount of I input from sugar and banana plantations through the Martha Brae River; but the exact nature of this input has not been evaluated. Neverthelessi this suggests that the ecosystem in bioluminescent bays might handle some agricultural runoff without permanent alteration. Domestic sewage and petrochemical wastes are already facts of life along Paerto Rico's southwestern coast, and it appears that these stresses are about to mashroom. Prevailing currents in the region are such that the entire inshore area will be subjected to these wastes. 'It cannot be expected that the inshore tropical plankton cormmmities will receive this stress w-ithout being altered, perhaps irreversibly. M@re research is needed. 514 Chapter 13-5 TROPICAL BLUE-WATER COASTS William E. Odum and John J. Walsh Institute of Marine Sciences I Rickenbacker Causeway Miami, Florida 33149 Where the deep blue oceans of the tropics approach populated continents they are usually protected from a sudden encounter with land by broad stretches of gently shoaling green water. In a few areas and under special circumstances, however, the green water zone is missing or greatly reduced. The result is what we will call a blue-water coast where a water mass with essentially open ocean conditions and communities intrudes to within a very short distance of the shore. Such regions may not be classified as estuarine in the sense that full oceanic salinities prevail. The great majority of blue-water coasts occur where oceanic islands such as Puerto Rico and Hawaii rise suddenly in t-ae midst of tropic, I oceans, Here the conditions are almost totally oceanic sad the meager runoff of water, nutrients and sediments from the steeply rising islan(B does not greatly alter the characteris- tics of the surrounding oceans. Continental coastal regions, on the other hand, are characterized by exten- sive drainage systems carrying great loads of sediments andnutrients which build sedimentary estuaries and broad expanses of coastal great2-water overlying gently sloping continental shelves. In only one area of the continental United States is there a true tropical blue-water coast where the land falls away quickly into the sea; this is along the southeast coast of Florida. Here the Florida Current flows within a few kilometers of the shore at a speed of two or three knots. Because oceanic conditions are continually and forcibly thrust upon this coastal enviroment by the Florida Current, there is no opportunity for the continental runoff to establish much of a green-vater zone, and consequently, blue-water conditions may reach to within three kilometers of the beach. On the southwest coast of Florida where there is no great current and the continental shelf slopes very gradually, the true blue-water zone lies over one hundred kilometers offshore. In comparing the blue-water coasts of Puerto Rico, Hawaii and southeast Florida certain general characteristics emerge, both physical and biological, which appear to be common to all three regions. These characteristics are basically those of the tropical open oceans themselves and have been only slight- ly modified by the proximity of land. PHYSICAL CHARACTERISTICS OF THE SYSTEM Tropical oceans and blue-water coasts are distinguished by extremely clear, transparent water which because of its low levels of phytoplankton, suspended and dissolved substances shows a deep cobalt blue color. This transparency allows a 515 much deeper penetration of incident surface radiation than occurs in turbid inshore waters or oceanic water at higher latitudes (Fig. Al The result is an euphotic zone which may extend well below 100 meters in contrast to green coastal waters where it is usually no deeper than 30 to 40 meters. Because the solar radiation remains more or less constant throughout the year in the tropics, the temperature of the surface waters shows little fluctuation. In the Florida Straits the annual variation of the surface 100 meters is only about 40 C (Fig. 2). This stable input of solar energy creates a remarkably deep isothermal layer overlying a permanent thermocline. Since there is no seasonal "pulse" or temperature change, the thermocline is rarely destroyed and its depth depends upon the amount and duration of surface winds. Off the Hawaiian Islands this permanent thermocline is ordinarily found at a dept;@ of 200-300 meters, but on the protected Waiarae coast of Oahu, where the strength of the prevailing trade winds-is reduced, the thermocline is found at 70-100 meters (Brock and Chamberlain, 1968). Thepermanency of the tropical thermocline serves effectively to prevent vertical mixing between the warm surface layer and the deep cooler waters. For this reason there can be little seasonal recharging of nutrients in the surface water as occurs at higher latitudes.. As a result tropical surface waters are characterized by extremely low standing stocks of nutrients (Fig. 2). Greater concentrations of nutrients are found where upwelling occurs as in the equatorial Pacific or where the thermocline rises near the surface as in the eastern tropical Pacific. Vertical patterns in blue water of the Gulf of Mexico are-sliown in Fig. Ia. ExPERtmEw r 0 02 Q-6)JO GO Chbr*Y11jM0) =bm (pqjd@ 22 * 24 00C 02 2-0 40 60 25 CE -: 0 7S 100[ 125 EXPERIMENT R 0 02 0-4 06 Q8 Uq at/! ch(omphyllqwm@ Cbm oml@) 16 8 20 22 24 26 *C 0 0-2 04 0.6 20 40 25, 50 75, tWO6 150L Vertical distributions of temperature, phosphate, chlorophyll a, and carbon for C14 ex. periments. I (2457'N, 84'08'W; 24-1%--6z), 11 (2e53N, 8e39'W; z5-iv.6:). For chlorophyll d and carbon: solid line, i zoo hours; dashed Line, oooo hours. 016 )W106 Fig. Ia., Vertical patterns in the Gulf of Mexico (Stogiel 1964). %6 PERCENTAGE OF SURFACE LLGHT cot 005 Ql Q5 50 1 0 20 .400 Ae -1 601 so Z 415 loci'", 0 M 12OR 140 4/38 160 442 180 Relatlon between depth and linradlation e@cpresswd as a pementago of the Hjht lust over the surfaw. scrics f4cality Latitude Ungitude Date Time Sky Sea Vrwd 414 GullStream 39-56IN 48-401W Sept. 15. 1935 W35-17:00 o slight &4 (S of Grand Banks) MA.T.) 43S Cayman 8" 18*381 79*121 Feb.28,1937 10:45-12:42 +o smooth 1, (13A.T.@ 442 GulffMWCo 29-14' 87*4U' April 11, 1937 10:30-11:18 b smooth I (C.B.T.) Fig. lb. Penetration of incident surface radiation (From Clarke 1938). 517 @%229zz@@_ 100 ........ . 0 200 ............................................... 300 400- : 00 00 to rOOL__ M J J A S 0 N.C) J F M A M J J A 8 0 N D J F M A M J J A S 0 N o .' ..... ;0 too- 0.0- 200 0.0 0:1 012 ZZ 00. IL W 3 43300 M J J A S N D J F M A M J J A S 0 N D J A M J J S 0 1968 1959 Ise! 0- too- its 0 , 1.0 Ili Its 111 11 .01 1. <11.1 3.0 200- 1.0 <9.0 40 IL Is 2 <8D <9D 91V 3.0 IJO 2 20 310 -LZ D 3.0 @ 0 .0 Ver@ical and seasonal distributions, 1958 through 1960, of: top, temperature; middle, phosphate-phosphorus in the unoer .300 rn: bottom, nitrite-nitrate nitrogen in the upper 300 ns. Fig. 2. Distribution of temperature, phosphate-phosphorus, and nitrite-nitrate-nitrogen according to season and water depth in the Florida Straits (From corcoran and Alex- ander 1963). 18D 2JO @/O 518 STRUCTURE OF THE BIOLOGICAL CONMUNITY Since the comunities of phytoplankton and animals associated with surface waters of blue-water coasts are typically pelagic, it is not surprising to find a great deal of similarity whether they be from the Hawaiian Islands or the southeast coast of Florida. This is especially noticeable with the mobile species at the higher trophic levels. perhaps, the most conspicuous feature of tropical blue-water co=runities is the great number of species present as compared with waters at higher latitudes. This phenomenon of higher numbers of species at lower latitudes holds for the dinoflagellates, foraminifera (see Fig. 3) and pelagic fishes, but does not apply to the diatoms which flourish in cold polar regions (Wood, 1965). Table 1 shows the number of holoplanktonic animals from six types of oceanic systems; clearly the tropical blue-waters far exceed any other water mass in numbers of species. Evolution seems to have favored greater numbers of species with less individuals rather than larger populations within species (Klopfer and Mac- Arthur, 196o, 1961). Whether this contributes to., or is a result of, the relatively stable enviromental conditions can only be guessed at. The Primary Producers Chaxacteristically many of the animals of the communities which lie below the surface waters make extensive diurnal vertical migrations, These movements serve to remo ve energy from surface waters to the depths,much more quickly than if energy transfer depended upon sinking rates alone, Movements .of herbivores into surface waters at night can be-correlated both with a sharp decline in phytoplankton numbers (Wood and Corcoran, 1960and a shift of the vertical maxima of phytoplankton(Fig. 4.). Phytoplankton of the tropical oceanic waters are dominated by very small algae callednannoplankton. Table 2 shows the increase of the relative importance of nannoplankton,over net plankton at lover latitutese Miller and Moore (1953) found that the nannoplankton biomass of the Florida Straits is up to 1000 times that of the net phytoplankton such as laxger diatoms and axmored dinoflagellates. Typically the nannoplankton include the Chrysomonad and Cryptomonad flagellates, small naked dinoflagellates and small diatoms. The Chrysomonads (cocolithophorea and golden brown flagellates) dominate in many tropical regions (Puen, 1967). The nannoplankton were overlooked in early considera- tions of standing crops of tropical waters because they were not retained by standard plankton nets. It has recently become apparent that they are capable of very rapid turnover, and accelerated primary production (Odum, Beyers and Armstrong, 1963). 519 CID 2 2 4 4 4- 8 41- 8- 0 0 16 9-16 16 42 8 4 2 Fig. 3- Contoured numbers for recent species of planktonic forayninifera. Equatorial centering of the species gradient is clear, as is the major source of noise introduced by ocean current transport of these planktonic organisms (From Stehli 1968). ORGANISMS PER LITER xIO 5 0 4 a 12 16 20 24 28 32 36 0- 40- Ui 80 ............ ............ Lo ........... 1-120. 0- LLJ 1100 1500 .............. 160- 1900 ------- 2300 0300 .............. 0700 ------- 2or 1100 Distribution of phytoplankton with depth over 24 hours in the Tongue of the Ocean. Fig. 4. Phytoplankton distribution according to water depth (From Wood and Corcoran l9b6)- 520 Table 1. N=bers of species of holoplanktonic animals in world oceans (From Russell 1935). Location N=ber of Species Warm oceans 1.378 Arctic and arctic boreal oceans 58 Antarctic and subantaretic oceans '90 Deep sea 34o Cosmopolitan 15 Total 1881 Table 2. Comparison of phytoplankton biomass caught in different regions of the oceans (From Yentsch and Ryther 1959). Ile percentage of phytoplankton biomass caught by a No. 25 plankton net in different regions of the oceans Location Latitude N of the total Author Scoresby Sound, East Greenland 70"N 66 Dway (1953) Off Plymouth, England .......... 50'N 10-26 HARVEY (1950) Long Island Sound ............. 41'N 9-56 RILEY (1941) Vineyard Sound ................ 41'N 2-47 New South Wales. -Australia ..... 33*S 3-4 WooD and DAVIS (1956) Tortugas ...................... 24*N I RILEY (1939) Table 3. Volume of net-caught zooplankton from the eastern tropical Pacific (From Mais and Jow 1960). Organism Fraction by volume Fraction by mmber Copepods 20% 63% Tunicates 15% 6% Chaetognaths 12% 15% Siphonophores 8% ]-% Euphausids 5% 5% Medusae 3% 1% Decapods 2% 1% Am phipods 1% 1% Ostracods ]-% 1% 521 The Decomposers In contrast to the situation in some shallow estuaries, the decomposers (fungi and bacteria) do not play a 'significant role in the blue-water coastal community. Although very.little quantitative data exist. concerning their presence and importance, the general impressiori.'is that their standing crops are exceedingly low (Wood, 1965) and that they are not important in the minerali- zation and recycling of nutrients (johanneb, 1968).' The Consumers Little quantitative d@ta exist c6nicerning_either plank-bonic or nek- tonic consumers of tropical seas, There are, ho.wever,fAirly complete faunal lists for many regions. Those for the Florida Current Are: Moore (1952) for the euphausids, Moore (1953) for the siphonophores, Owre,(ig6o) for tile chaetognaths) Ovre (1962) for the copepods,'Voss (1956).for the cephalopods, Wormelle (1962) for the pter ods, Steiger (l969) for'the benthic fishes and OP Devaney (1969) for the midwater fishes. The most important herbivores of blue-vater coasts are the copepods. In the Florida Current they constitute at least one third of the animal bio- mass taken in a plankton net (tsharah, 1957) and are of even grPater importance numerically; Their importance in the eastern tropical Pacific is shown in Table 4. Comparison of phosphorus cycling in inshore waters and offshore blue waters (From Pomeroy 1.961) Item Concentration Turnover rate Residence time mg atoms/@O mg atoms/m3/ hr hrs Surface coastal water off Georgia, 31 N. Lat. 0.1 - 0.8 o.1 - o.4 34 - 155 Gulf stream surface water off Georgia 0.1 0.8 4 522 Table 3. Another group which are predominantly herbivorous are the euphausids, although they are not as numerous in the tropical surface waters as in the Antarctic. On the other hand, pteropods,, heteropods and tunicates are far more important in tropical waters than toward the poles. Major planktonic carnivores include siphonophores, chaetognaths, fish larvae and juvenile cephalopods. The fish larvae of blue-water coasts are especially numerous due to the tendency of many coastal and estuarine fishes to move offshore to spawn. In the surface waters the larger carnivores are represented during the day by pelagic fishes, but at night diurnal mirgrations bring mesopelagic squids and fishes into predominance. As previously mentioned the large pelagic fishes are very similar in all tropical oceans. Sports fishermen off Florida@ Puerto Rico and Hawaii all catch yellowfin tuna Thunnus albacores, skipjack tuna Katsuwonus pe smis., dolphin Corypha hippurus, wahoo 77c-Et-hoc@bium solandri, amberjack Seriola spp., rainbow runner Elagatis. bipinnulatus along with species of sailfish and marlin. Drifting Subsystems or "Superstrates" A special subsystem of the blue-water regions are the drifting communities. These are formed when pelagic fishes and other organisms become associated with drifting material such as Sargassum (see Gordon, 1938), Physalia, coconuts, logs, boards, pumice, coconut fx:o-ndsl- slabs of cork, rafts and7o-ther flotsam. Commer- cial and sportsfishermen have long'realized the value of concentrating their efforts around such objects.- Japanese and Indonesian fishermen even construct floating rafts which they anchor and visit again and again for good catches of fish. Miami charterboat fishermen can usually expect to take at least one dolphin underneath a floating piece of wood. Catches of several hundred fish have been recorded from under a single plank. Gooding and Magnuson (1967) present a good review of past work and describe their own experience with a floating raft in the open Pacific. Over a period of many days they observed hundreds of adult and juvenile fishes around the raft including 27 species which were permanent residents. They concluded that floating objects were beneficial to the fish in three ways: (1) they provided portection from predation for smaller fishes, (2) they concentrated the food supply for larger fishes and (3) they served as "cleaning stations" for the removal of parasites from the laxger fishes by smaller ones. In conclusion they described floating objects as a relatively rare "superstrate" in an environment notable for its horizontal homogeneity. Such superstrates have the same ecological significance to certain pelagic fishes that a substrate has to inshore fisher. Sargass associations are shown in Fig. 5. The Neuston Another type of superstrate is the air-vater interface. Living in close association with this layer are the animals known as neuston (summarized by David, 1965). Included are the only insects which live in the open ocean, the five species of Halobates or water striders, along with a number of organisms which float on the surface ( ysalia and Velella) and many more which exist just below the surface film. All these animals are subject to great stress 523 The faunal association of a rargassum bladder, Texas coast. The hydroids are Obelia anc'. @ertrdaria. the pyrnogonid is Twivstilum orbiculare. Other forms in(lude the sarpassurn anemone, Anemonia sargassensis, a capiellid, a flatworm, a small tubiculous polychaetes (Spirorbis), -k juvenile ophiuran and a small colony of bryozoa. (From Hedgpeth, 19443.) -r7 Az@ t -Displaced benthos of,the Sargassum The examples illustrated are taken from Sargassurn found near shore in the northern Gulf of Mexico, and include Scyllaea pdagica,. Portunus sayi, Histrio histrio, A nemonia sargassensis, Pkly- itereis duinerili, Lifiopa inclanoslonta, Latreutes fucorunt, Bryozoa, serpulid worms, and hydroids. Inset: details of hydroids, a caprellid, the pycnogonid Tanystylum orbiculare, a juvenile ophiurant and a polyclad worm. P'ig. 5. Floating -Sargassim a.ssociation (Hedgepeth, 1948, 1957). 524 conditions since the physical and chemical conditions of the environment are capable of greater and more rapid changes then occur elsewhere in the open sea. In addition they are exposed to the full spectrum of sunlight. The neuston are.characterized by an intense blue color ---- quite different 'from plankton in the water column a few meters below. Th 'is blue color which is found in copepods,, decapod crustacea, medusae, fish, squid and salps, is probably a form of adaptive coloration affording some concealment in the brilliant blue surface water. This color is due to pigments in some animals and interference effects in others* PRIMARY PRODUCTIVITY OF THE SYSTEM The scarcity of dissolved nutrients in tropical surface waters has been interpreted in the past as, an indication that primary production proceeds at low levels creating practically a biological desert (Hensen, 1890; Lobiahn 1917; Sverdrup, Johnson,aA4 Fleming,19@2). This concept was further strene@hhened by observations of generally law standing crops of phytoplankton in the tropics. More recently it has been pointed out by Pomeroy (1961) that measurements of dissolved nutrients in natural waters give a very poor indicatiori.of avail- ability since most of the nutrients at any given moment may exist inside living cellp. If these cells axe capable of turning over the nutrients at a rapid rate, then there will be a constant supply for other cells which are able to concentrate nutrients from a dilute solution. This, in fact, appears to be the case in tropical seas where the phytoplankton is dominated by small forms with rapid metabolic rates. Pomeroy (1961) has compared the phosphorus budget for 'a coastal green- water system off Georgia with the Gulf Streat lying further oft6hore (Table 4). Although the concentration of ]@hosphorius is much lower in the Gulf Stream than in the coastal water, the turnover rate ishigher and the residence time far shorter in the blue-water. One rdasbnlfor' these rapid turnover rates is the ability of many organisms to"&Ifsorb and utilize nutrients vhiie they are still in an,organic form rather then waiting for the slow process of minerali- zation to an inorganic form. This rapid turnover of nutrients by.organisms; coupled with..(l) a very deep euphotic zone, which may be three.to four times de6pdjr.than in &een-water, and (2).a constant supply of solar energy' thi=gh out the year suggests that tropical surface waters may be moreproductive on a year-round basis than was formerly supposed. Walsh (lj69) compared the seasonal variation of Antarctic and Florida Current phytoplankton.numbers throughout the re.s- pective euphotic zones (Fig.6a) and found the constant law standihg crops of the tropics compar- able to the wild fluctuation:s of the Antarctic on an annual basis. As further evidence, yearly production for tropical blue-water and other 6cean'c areas are presented in Table 5. Such data are. not strictly comparable since 14C. light and dark bottle 02 and nutrient depletion methods of measuring primary production are not standardized. However, the data can be used as a rough approximation of the energy input of these areas. From the table t@e following 525 J A S 0 N D J F M A M i i Cli 0, a Cli q ELTANIN 0 27 A U) _j w P0 z w w 0 EASTWIND 66 => 15 LL _j FLORIDA STRAITS 66 ELTANIN CL 10 23 0 T FLORIDA A STRAITS 65 L L 0 w Cma ........................ z Annual variation of standing crop in th6`Str1Aits of Morida(solid lines) and the suggested annual variation@ of -areas in the Southern Ocean(dashod are observed and dotted are postulated) Fig.6a. Seasonal variation of Antarctic and Florida Current phytoplankton (From Walsh 1969). 526 Table 5. Yearly production of various oceanic areas. Area Yearly_Rates Type of Source (g cle-fi_@ar) Production Tropical B3.ue Water Florida Current 67-182-5 Net"Gross Corcoran and Alexander (1963) Sargasso Sea 16T Gross Riley, Stommel, and Bumpus (1949) Sargasso Sea 72 Net-Gross Ryther (1963) Hawaii 3T Net-Gross Steemann Nielsen.(1-954) Hawaii 123 Gross Doty and Oguri (1956) Marshall Islands 182.5 Gross Sargent and Austin (1954) Indian Ocean 73-89.3 Net-Gross Steemann Nielsen and Jensen (1957) Caribbean 51-70 Eet-Gross Steemann Nielsen and Jensen (1957) Antarctic Bellingshausen Sea 4.8 Net-Gross Burkholder and Mandelli (1965) Bellingshausen Sea 28.8 Net-Gross El-Sayed (1967) Bransfield Strait 26.8 Net-Gross Burkholder and Mandelli (1965) Bransfield Strait. 331.2 Net-Gross El-Sayed (1967) Weddell Sea 84 Net-Gross El-Sayed and Mandelli (1965) Drake Passage 92.4 Net-Gross El-Sayed (3-967) Marguerite Bay 55.2 Net-Gross El-Sayed (1967) Antarctic Ocean 100 Gross Ryther (1963) Arctic Polar sea 1.0 Net-Gross Apollonio (1959) Polar sea 1.0 Net-Gross English (1959), Tempera;T,e Georges Bank 309 Gross Riley, Stomel, and Bumpus (1942) Long Island Sound 47o Gross Riley (1956) Benguela Current 167-912 Net-Gross Steemann Nielsen (1954) Continental slope off 100 Gross Ryther and Yentsch (1958) New York Coastal water off New York 16o Gross Ryther and Yentsch (1958) North Sea 45-100 Gross Steele (1958) *Compiled by John Walsh. In many cases annual production vas estimated from the original authors.' daily production rates. 527 conclusions can be drawn: (1) tropical blue-vat6r systems may be equivalentto or more productive than polar regions, and (2) temperate systems with seasonal pulse energy and nutrient cycles are more productive than tropical blue-water or single pulse polar systems. Seasonal Cycles--A Possible Steady State? Since primary production appesrs to proceed at a constant low level throughout the year in the tropics, it has been suggested that these blue- water systems approach a steady state situation. Cushing (1959aed two extreme types of production cycles, one unbalanced with strong seasonal fluctuations as occurs in temperate and cold seas and the other "fully balanced!' or in a steady state with no change in standing crops as found in non-upwelling tropical regions. The occurrence of appaxent yearly balances between phytoplankton production and zooplankton standing crops in tropical ocean areas has been described by Holmes (1958) for the eastern tropical Pacific, Menzel and Ryther (ig6o) for the sub-tropical Sargasso Sea andBsbarah (1957) for the Florida Straits. Blackburn (1966) working in a specific area of the eastern tropical Pacific concluded that standing crops of phytoplankton, herbivores and primary carnivores occun,ed in ways that were consistent with steady state conditions. He found such conditions lacking for other areas of the eastern tropical Pacific, but did not deny their possible existence. In studyJ-g Bsharah's seasonal distribution of total phosphorus in the Florida Straits (Fig.6b) it qppeaxs that a steady state is approached,, although some fluctuation is apparent. More data axeneeded to determine whether these small fluctuations are of significance in the annual operation of the system or merely "noise". Boundary Effects As a general rule the standing-stocks of both dissolved organic and in- organic compounds and the biomass of organisms increase as blue-vater systems approach'land (discussed for Havaii by Doty and Oguri.. 1956). The cause for this enrichment can be traced to (1) runoff from land, (2) primary production of inshore coastal systems and (3) coastal upvelling. The enrichment phenomenon becomes more pronounced when the land is continental rather than an oceanic island. With very small 'islands the effect may be negligible. Fig. 7 shows the characteristics of a blue-vater system which approaches a small tropical Pacific Island. It is interesting to note that oceanic conditions remain relative- ly unchanged to within less than a mile of the shore. Along continental blue-vater coasts the effects may be much greater. Corcoran (1967) has shown for the Florida Current (Figs. 8 and 9) that the concentrations of both soluble iron and copper increase markedly as the Florida coast is approached. Concentrations in the center of the Florida Straits were less then half that of the shallow Fowey Rocks near Miami. The Cay Cay region lying offshore from the Bahama Islands had higher concentrations than the center of the Straits., but were significantly lover than along the Florida coast. At the inshore boundary of blue-water there is usually a rise in the standing stocks at the higher trophic levels. It is no accident that the world's 5.28 0.0108 ZOOPLANKTON 0,004- 0.8 NANNOPLANKTON 04- 0 B-OOINORGANIC PHOSPHORUS 6. 4. 0 0 36.00 DISSOLVED PHOSPHORUS IL 32-00- 28.00- Z 24.00 20.00- 16.00- 12.00- SJO0 4,00- 0 t WIPTER SPRING SUMMER AUTUMN Diagram showing distribution of total phosphorus in euphotic zone at Forty-Mile Station. Fig. ob. seasonal distribution of total phosphorus in the Florida Straits (From Bsharah 1957)- 529 s IN s N -3' 4Y < 34-55 24 34.6 ---- 23.5_ 34.7 23 40 22 - Go -34.6 so T OC S%. -34 .5 34.6 GO, 6' 10 69 Go 6' STATION NUMBER STATION NUMBER 0 mdes is IN s N -3 42. 0 T > 5.0 < 0.4 49 to 17 _7-0.4 40 . ................... 4.9 7-0.5 60 6: 1 RAPID RAPID DECREASE INCREASE 90 P04 11: 02 M1./L qm-at./L 70 69 60 )o 69 67 STATION NUMBER STATION NUMBER Socorro Island Survey. Distributions of temperature VC), salinity (*/oo) dissoll-rd ox1jen (ml./L.), and Inorganic phophate (A gm-at./L) in the southern S@ctjon. T@, sh ed areas.in the temperature distribution Indicate nearly vertically-isothermal wMer Fig. 7. Blue water coast characteristics near a smll tropical island in the Pacific (From BennetT am 5chaefer lqo0). J< 3/4 55 S. >50 530 5 0 Is 20 0 5 10 0 5 10 15 0 5 10 is 0 5 0 0 5 10 0 5 1.0 IP 20 0 S MO STAT 104 NO I STATION 0 8 400 STATII N 2 STATION No 3 STATION No f STATION No.? STATION No 4 STATION MIS The vertical and horizontal distribution of the total soluble copper between Fowey Rocks and Cm Cay during January 1963. Fig. 8. Concentration of soluble copper in the Florida Current (From Corcoran 1967)- STA. No. I - 2 - 3 - 4 - 5 -6 - 7 -8 pg Fe/L 0 25 50 75 0 25 0 25 0 25 0 25 0 25 0 25 0 25 0 . . . . . . 100 200. 300- 400 - CL 500- 60o- 700 - 800 The vertical and horizontal distribution of the total soluble iron in the Straits of Florida between Fowey Rocks and Cit Cay. Fig. 9. Concentration of soluble iron in the Florida Current (From Corcoran 1967)- 00 STATION 531 greatest tropical sport fishing regions are located where blue-water brushes land masses. These include .the "edges" of the Florida Current off south- east Florida and Bimini, the blue-vater of Havaii., the north coast of Puerto Rico, Bermuda and the Challenger banks, and the Pacific coast of western Mexico off Acapulco and Baja California. Miami charter boat captains spend 90 peTceni of their trolling time along the "edge" where the blue waters of the Florida.Current change horizontally within a fev,meters to the green water over-lying the coral reefs. Some of this increased biomass of the blue-water coast is supported by the primary production of 'inshore reefs and seagrass co'v'ered bays. In many cases entire trophic levels are bypassed since pelagic fishes are able to feed upon benthic forms which in turn feed directly upon benthic plants and detritus. The effect of sucha shortened food chain is to provide more top carnivores with little increase in primary production. ENERGY FLOW THROUGH THE COMMUNITY To visualize the one-way flow of energy through a coastal blue-water community it is necessary to consider the following points: (1) Most of the energy is fixed in the euphotic.zone by phytoplankton. These organisms serve as the dn .ine which drives t system. 'he (2) There is a small.input of energy from inshore and estuarine 'primary production. Thisarrives offshore in the form of large particles (such as Thalassia leaves), small particles and dissolved organic matter.. (3) inorganic and organic compounds are recycled very rapidly in the surface waters by phytoplankton, colorless flagellates and zooplankton with little assistance from bacteria and fungi (discussed at length by Johannes, 1968). (4) There is a general downward movement of much of the primary production from the euphotic zone. This is accomplished by sinking of phytoplankton, zoo- plankton and fecal pellets. Perhaps, most important is the vertical diurnal migration by animals from below which speeds up the downward movement of organic matter@ Energy transfer to the consumer trophic levels of oceanic systems is poorly understood. Blackburn (1966) has estimated the relatiofiships existing between the standing crops of three successive trophic levels in the eastern tropical Pacific. The ratio between cop6pods and phytoplankton was estimated by weight of carbon while that between the carnivores and zooplankton was derived from displacem6fit 'volume. Both relationships were roughly 0.04. For various reasons it was concluded that the actual efficiency ratios of the food chain for standing crops of all material at the appropriate trophic levels would be higher. Certainlyj more data aile needed, although it becomes more and more difficult to make any type of meaningful estimation at the higher trcphic levels since the consumers become more non-selective in their choice of foods. The yellowfin tuna, which is considered to be atop carnivore, has been recorded to ingest species from at least 12 orders of invertebrates and 44 families of fishes (Alverson, 1963). 532 WASTES AND BLTJE-WATER COASTS--A BOTTONIESS GARBAGE CAN? the high piled scow of garbage, bright-colored, white-flecked, ill smelling, now tilted on its sides., spills off its load into the blue water, turning it a pale green to a depth of four or five fathoms as the load spreads across the surface, the sinkable part going down and the-flotsam of palm fronds., corks, bottles, and used electric light globes, seasoned with an occasional condom or a'deep floating corset,, the torn leaves of a student's exercise book, a well-inflated dog, the occasional rat, the no-longer distinguished cat,. the stream with no visible flow, takes five loads of this a day when things axe going well in La Habana and in ten miles along the coast it is cleax and blue and unimpressed as it was ever before the tug hauled out the scow Hemingway (@935)- Clearly, the blue-water coast with its association with open ocean systems offers. an attractive solution to a society which is rapidly producing more and more waste products. There is a feeling as expressed in the p@ssage above of the infinite ability of the sea to absorb all of man's capacity to manufacture garbage and sewage. This is a common and widespread feeling. It might be pointed out that at the turn of the century there was another commonly accepted theory about the sea--that it was an inexhaustible source of food fishes. Let us hope that present feelings on waste disposal are'not'as''erroneous.' There are indications that it may not be possible to pollute the open ocean without some adverse feedback from the system. Pearcy gnd Osterberg (1968) r have recently demonstrated that very small concentrations of 5Zn caiTipd.down the Columbia River from the Hanford reactors and @Mto the North Pacific have become concentrated to significant levels in the pdpulair food and gaiaefish, the albacore Thunnus alalunga. Moreover, radionuclides from the same source have been found in many marine organisms off Oregon (Osterberg, Peaxcy and Curl, 1964; Pearcy and Osterberg, 1967; Carey, Pe'axcy and Osterberg, 1966b). Even more startling is the finding by Wurster and Wingate (1968) of dangerous ievels of DDT and its metabolites in the Bermuda Petrel. This is highly interesting since this bird feeds only in the open ocean regions of the North Atlantic. It is at first difficult to conceive of,such an organism obtaining potentially lethal amounts of DDT from an area so f6,r removed.from pesticide application. The effects of sewage disposal on blue-vater coasts axe not at all cleax. Along the southeast coast of Florida there are a number of sewer out- falls which dump raw or partially treated sewage directly onto the edge of the Florida Current. From this practice three questions have arisen: (1) -what are the effects of sewage enrichment upon the blue-vater 6ystem--great effects might be expected since this is a stable low nutrient environment-@-(2) how much of the material finds its way back to shore by means of inshore eddies and (3) what is the fate of potentially dangerous microorganisms in the effluent? The questions remain unanswered, but investigations are underway at Flori'da Atlantic University at Boca Raton. 533 Economical Importance of Blue-Water Coasts A primary value of blue-vater coasts is to the fisherman--especially the sportfi-aherman. Florida, Puerto Rico and Hawaii all have large sport- fishing fleets which emNloy many people and combined are worth millions of dollars annually. These fleets are dependent to a great extent upon the pelagic fishes of the open ocean and to a.lesser extent upon reef and inshore fishes.. Many other fishermen and boats use the blue-vater regions on a part time basis for recreation. These amateur fishermen number in the thousands. On a weekend it is not unusual to see hundreds of private and charter fishing boats along the edge of the Florida Current between West Palm Beach and Miami. Any consideration of the future effects of pollution on the blue-water coasts should take as its first priority the effects on the commercial and gamefish stocks. COASTAL Nil' DlkrF- DUE GAYLORD No. 2333 PRINTED IN U.SA 3 6668 14100 2552