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116 X@/ 69. %13 10, Cj 1 6. 14 23 56 24 17 6* 23 3, 6- 39 ,OirF1, .7. :'" -a, 7, t9 6; 6@ .13 22 25 It .41 3. 14 BAN IA6 10, i21 46 :-;i,,/12,7 @ , @, @@1.3L II 35 28 43 54 66 33 29 ", 13' 101 3b 43 43 91 55 41 30 H 14 29 S. -C"2loo 55 .Ia, '71 23 32 56 73 94'.100--, .73 152 453 (239 ft) 242 j193 ft 28 ', 'I's 7, 6' 35 43 67 34 53 63 140 50 @30 13 40 5\ - 6 191 57 87 -A9 10' 37 2.,10i27 36 51 84 45 .,9 7 74 52,, 150 66 23 38- 8 8 7 6, 115 :23 33 9t 147 110 60 13 - Puntan Hagma 3.1157 74 loo 8o 158 29 34 19 3, 6.41 -09 1 " 18, 37 93 61. 35 26 24 6 121 173 Do_, 45 27 @--. I- -..- 138 2. 26 46 56 68 92 69 184 195 91 70 48 36 930 145 39 " .'21 39 175 M 75 00', 1 @o ------- 73 45 48 213 40 67 89 60 152 190 _ _-145 -95 _ - - - -- -," 67 26 190 2JO 150 145 80 ---, 23 35 54 879152 200 200 220 180 150 61 '17095" 429 34 183 @o 17 12 "o 200 'go '9' '00 ----------- 00 --------- ,15!51 23@ 2.. 4,;1432 416i49 73 @3 155 21. 200 290M 280 '2130M M145 291 280 330 210 190 10 115 '9' 48 @co 165 PIROEPAREb FOR 'S' 14 ' "70 220 300 310 3 S, 17 \,41 56 100 235 320 2. .*',16 14 19 i149 90 290 300 247 28 Cbrnmo,nwealth-of the Northerrjo Mariana 13@lands- 457 89 190 200 265 341 30 165 245 "3 140 120 37 (2W61, 2- 90 155 210 348 178 2, 16 128 36 57 9, 80 220 290 30; 340 380 78 410 32 42 91 r, py's ical lginnirW Office 368 20, 40 58 96 " -- 130 273 300 364 15 32 90 100- - 00 30 145 3" 12g4975 17 47 71 91 86 -100, 141 4@1 31 125 265 '@2 25 26 35 50 57 64 91 200 280 333 205 I,3,25366 00 350 410 39 9' 1', 30 28 31 175 195 255 457 7145 ?85 521160 32COASTAL ZONE 500 @0- 97o 158 278 469 68 12 96'190 238 (223 ft) 78,140 4 34 272 INFORMAT A CENTER 41 510 "9" 37 00 116' 290 232 15- 89 370 200 260 33 @6 871190 4,, 511 37 138 t13, 7@ '71 330 (292 ft) 39 loo 238 295 61 95 3500 @ 1, @., 1, @ @ @ I @... 1,0 20 500 :)7' 16 01 305 3"\ ...... -l".. 55" -8 60 115 240 21 ,% 0 510 45 3,@, @ll@I/",d/ V 500 '90 (364 ft) 105 2.02 E @@GN Ic 121 150 00 480 210 62 1 oo 178 '21 370 S_ 140 520 60 PREP A.2 'RE"Y 390 15 26 loo 332 so 1300 15 379 i16 v"1 6 'Bas n Environnl6htbrc0_nsuItan%, ci,; Ic "o 7 /f 420 8@ 530 6 185 88 250 '?20 15 ol <, @-440 16 7, 3N ft.@ 35 - 385 9" Ill 984- @10 500 /StPTEMBE 22 373 55o --06' 12 2B5 37 230 440 26 Z,@ 33 o,"22 78 165 190 28 110 62 74 34 50 75 220 "o 081 500 '29 SAIPAN `105 7@ 36 196 90 8, @14o 76 an 'd. 333 @00 ...... BAHIA LAULAU Puntan Naft :9, 103 13 4. 35 From U. S. Navy sumays in 1944 149 210 367 SCALE 1:20,000 34 FINAL REPORT BIOLOGICAL AND PHYSICAL SURVEY OF BAHIA LAULAU, SAIPAN Prepared for Commonwealth of the Northern Mariana Islands Planning /Energy Office Under a Grant from the U. S. Department of Commerce, Office of Coastal Zone Management Coastal Energy Impact Program Prepared by Pacific Basin Environmental Consultants, Inc. US Department of Commerce NOAA Coastal Services Center Library 2234 South Hobson Avenue Charleston, SC 29405-2413 September 1984 TABLE OF CONTENTS Page LIST OF FIGURES . . . . . . . . . . . . . . . . .. . . . . . . . . . iv LIST OF TABLES . . . . . . . . . . . . . . . . . ... . . . . . . . . . v LIST OF PLATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii SUMMARY OF FINDINGS . . . . . . . . . . . . . . . :.... ... . . . . . . S-1 INTRODUCTION . . . . . . . . . . . . . . . . . . ... . . . . . . . . 1 Scope of Work . . . . . . . . ... . . . . . . . . . . . . . . . . . 4 SURVEY TEAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . 7 GENERAL METHODS AND PROCEDURES . . . . . . . . . . . . . . . . . 8 HISTORICAL INFORMATION . . . . . . . . . . ............ 9 Introduction and General Background . . . . . . . . . .. . . . . . 9* Methods . . . . . . . . . . . . . . . . .. o . . . . . . . . . . . . 10 Results . . . . . . . . . . . . .. . . . . o . . . . . . .. . . . . . 10 Laulau Bay Archaeological Site . ... . . . . . . . . .. . . . . . 10 Excavations at Bahia Laulau . . . ... . . . . . . . . . . . . . 13 Military Significance . . . . . . . . . . . . .. . . . . . : . . . 14 Literature Cited . . . . . . . . . . . . . . . . . . . . . . . : . . . 16 PHYSIOGRAPHY AND SHORELINE SITE DESCRIPTIONS .. . . . . . . . . 17 Introduction . . . . . . . . . . . . . . .. . . . . . . . . . .. . . . 17 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Results . . . . . . . . . . . . . . . . . . . . . ... . . .. . . . . . 17 Conclusions . . . . . . . . . . . . . . . . . . . . . . . ... . . . 20 Literature Cited . . . . . . . . . . . . . . . ... . . . . .... . . . 22 GEOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . 23 Introduction . . . . . . . . . . . . . . . . . . . . . 23 Methods . . . . . . . . . . . . . . . . . 23 Results . . . . . . . . . . . . . . . . . . . . 30 Site 1, Sabanen Kagman . . . . . . . . . . . . . . ... . . . 30 Site 2, Unai Bapot . . . . . . . . . . . . . . . . . . 36 Site 3, Unai Laulau . . . . . . . . . . . . . . . . . . 40 Site 4, Unai Dandan . . . . . . . . . . . . . . . . . ..... . . 43 Discussion. 45 Comparison of Sites . . . . . . . . . . . . . . . . . .... . . 45 Conclusions . . . . . . . . . . . . . . . . . . . . . . ... . . 46 Literature Cited:, . . . . . . . . . . . . . . . . . . . . . . .. . . . 48 PHYSICAL PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . 49 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 49 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . 49 Results . . . . . o . . . . . . . . . . . . . . . . . . . . . . . . 53 Air Temperature . . . . . . . . . . . . . . . . o . . . . . . 53 Page Relative Humidity . . . . . . . . . . . . . 53 Rainfall . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 53 Wind . . . . . . . ... . . . . . . . . . . . . . . . ... . . . 54 Water Surface Temperature . . . . ... . . . . . . . 54 Tropical Disturbances and Typhoons .. . . . . . . 55 Oceanic Temperature and Salinity Profiles . . . . . . . . 55 Bottom Profile . . . . . . . . . . . ... . . . . . .. ... .. . . . 56 Current Patterns . . . . . . . . . . . .. . . . . 58 Of f shore . . . . . . . . . . . . . . 60 Inshore . . . . . . . . . . . . . . . . . . . . ...... . . . 65 Water Quality . . . . . . . . . . . . . . . . ... ....... . . . . 66 Discussion and Conclusions . . . . . . . . . . . . ........ 68 Literature Cited . . . . . . . . . . . . . . . . .. 70 TERRESTRIAL FLORA AND FAUNA . . . . . . . . ..... 71 Flo r*a . . . . . . . . . . . . . . . . . . . . . . . 71 Introduction . . . . . . . . . . . . . . . . . . 71 Methods . . . . . . . . . . . . . . . . . . ... . ... . . . . . 72 Results . . . . . . . . . . . . . . . . . . . .. . . . . . 73 Site I . . . . . . . . . . . . . . . . . . . . 73 Sites 2 and 3 . . . . . . . . . . . . . . . . 73 Beach Strand . . . . . . . . . . . . . . . . . 75 Site 4 . . . . . . . . . . . . . . . . . . . . ..... . . . . . 76 Discussion and Conclusions . . . . . . . . ... .... ... . . . . 76 Literature Cited . . . . . . . . . . . . . . . . . ..... . . . . . 78 Fauna . . . ... . . . . . . . . . . . : . . . . .... 79 Introduction . . . . . . . . . . . . . . . . . . . . . . 79 Methods . . . . . . . . . . . . . . . ... . . . . . 80 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Avifauna . . . . . . . . . . . . . . . . . . . . . . . . 81 Reptiles and Amphibians . . . . . . . . . .. . . . . 82 Mammals . . . . . . . . . . . . . . . . . . I.... . . . . . 83 Discussion and Conclusions . . . . . . . . . . . i. . . . . . . 85 Literature Cited . . . . . . . . . . . . . . . ... .. ... . . . . 87 MARINE FLORA AND FAUNA . . . . . . . . . . . . . . . . . 89 Marine Plants . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Introduction . . . . . . ... . . . . . . . . . . . ..... . . . . 89 Methods . . . . . . . . . . . . . . . . . . . . 89 Results . . . . . . . . . . . . . . . . . . . . 89 Site 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Site'la . . . . . . . . . . . . . . . . . . . . ... . . . . . 90 Site 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 .Site 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 .Site 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Discussion and Conclusions . . . . . . . . . . . . . . . . . . 93 Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . 96 Plankton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Methods 97 . . . J. . ... . . . . : - : : : , , , , * : : : : , , , Results and Discussion . . . . . . . . . . . 98 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Literature Cited . . . . ... . ... . . . . . . . . . . . . . . . 103 Page Corals . . . . . . . . . . . . . . . . . . . . . . . . . 105 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Results . . . . . . . . . . . . ... . . 108 Description of Reefs and Coral Communities . . . . . . . . . 108 Zonation . . . . . . . . . . . . . . . . . . . . . . . . 108 Coral Distribution . . . . . . . . . . . . I . . . . . . . . . 109 Discussion and Conclusions . . . . . . . ...... . . . . . . . . 109 Literature Cited . . . . . . . . . . . . . . .... . . . . . . . . 114 M acroinverteb rates . . . . . . . . . . . . . . . . . . . . . . . . 115 Introduction . . . . . . . . . . . . . . . . . .. . . . . . . . . 115 Methods . o . . . . ... . . . . . . . . . . . . . . . . . 115 Results . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Discussion and Con clusions . . . . . . . . . . . . . . . . . . 116 Literature Cited . . . . . . . . . . . .. . . . . . . . . . . . . 119 Fishes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Results . . . . . . . . . . . . . . . . . . . 122 Species Diversity . . . . . . . . . . . . . . . . . 122 Juvenile Fishes . . . . . . . . . . 123* Food Fishes . . . . ; . . . . . . . . . . . . . . . . . . . 124 Fish Density . . . . . . . . . . . . . . . . . . . . . . .. . 126 Discussion . . . . . . . . . . . . .... . . . . . . .. . . . . . . 127 Conclusions . . . . . . . . . . 130 Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . 131 Marine Turtles and Mammals . . . . . . . . . . . . . . . . . . . . 133 Introduction . . . . . . . . . . . . . . . . . . . 133 Methods . . . . . . . . . . . 133 . . . . . . . . . . . . . . Results . . . . . . . ... . . . . . ... . . . . . . . . .. . . . 134 Discussion and Conclusions . . . . . . . . . . ... . . . . . . 135 OTEC DEVELOPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Introduction . . . . . . . . . . . . . . . . 137 Potential Environmental Impacts Related to OTEC Development . . . 144 Risk of Credible Accidents Related to OTEC Development 147 Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . 149 GENERAL DISCUSSIONS . . . . . 151 Physical Resources . . . . . . . ... . . . 151 Biological Resources . . . . . . . . . . . . . ... . . . . .. : 151 Recreational Resources . . . . . . . . . . . . . . . . . . 152 Snorkeling and Scuba Diving . . . . . . . . . . . . ... 152 Fishing and Boating . . . . . . . . . . . . . . . . . . . . . . 152 Resource Degradation . . . . . . . . . . . . . . . . . . . . 153 Unique Areas and Features . . . . . . . . . . . . . . . . ... . . 154 Literature Cited: .. . . . . . . . . . . . . . . . . . . . . . . . . . 155 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 157 RECOMMENDATIONS . .. . . . . . . . . . . . . . . . . . . . . . . . . 159 APPENDICES Appendix A - Tables 1,2, 4-17 Appendix B - Plates LIST OF FIGURES Figure Page 1. Project location map . . ... . . . . . . . . . . . . . . . . . . . . 2 2. Bahia Laulau showing the location of the proposed OTEC facility and. the five study Sites . . . ... . . . . . . . . . . . . .. 3 3 a. Principal archaeological sites of Saipan b. Magicienne Bay, Saipan, showing location.of Laulau and Bapot Sites . . . . . . . . . . . . . . . . . .. . ..... . . . . 11 4 a. Vertical profiles of Sites 1, la, 2, 3 and 4 at Bahia Laulau showing terrestrial topography . . . . . . . . . . . .. 18 b. Underwater vertical profiles of Sites 1, la, 2, 3 and A showing submarine topography, reef zones, water depth and relative distribution of corals and sediments . . . . . . . . .. 19 5. Reference map of Saipan . .. . . . . . . . . . . ... . . .. . . . . 24 6. Reference and topographic base map of Bahia Laulau, study sites with' vertical section lines indicated . . . . . ... . .. 25 7 a,b.. V ertical cross-section at Sabanen Hagman 31 8. Map of fracture traces and mass wasting at Site 1 . . . . . . 34 9 a,b. Vertical cross-sections at Unai Bapot. Vicinity of Site 2 . . . . 37 10 a,b. Vertical cross-section at Unai Laulau. Vicinity of Site 3 . . . . 41 11. Vertical cross-section at Unai Dandan. Vicinity of Site.-4 . . . . . 44 12. Temperature profile from surface to depth of 457 m (150.0 ft) of f proposed OTEC site . . . . . . . . . . . . . . . . . . . . . . . . 50 13. Limits of study sites 1-4, proposed OTEC site, bathyme tric profile water. quality monitoring stations . . . . . . . . . . . . . . . . . 52 14. Bottom profile from shoreline to a depth of 457 m (2400 ft) off proposed OTEC site . . . . . . . . . . . . . . . . . . . . . . . . 57 15. Theoret *ical model of water circulation patterns in Bahia Laulau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 16. Map of Bahia Laulau showing 1 m and 5 m drift drogue tracks and velocity, plankton sampling stations: a. November 5-6, 1982 . . . . . . . . . . . . . . . . . . . . . 61 b. February 9, 1983 . . . . . . . . . . . . . . . . . . . . . . 62 c. May 10-11, 1983 . . . . . . . . . . . . . . . . . . . .. . . . 63 d. September Z9-30, 1983 . . . ... . . . . . . . . . . . . . . . 64 17. Potential OTEC thermal resource . . . . . . . . . . . . . . . . . .. 139 iv LIST OF TABLES Table Page 1. Rock units mapped in the vicinity of Bahia Laulau, Saipan . . . . AA 2. Soil units mapped in vicinity of Bahia Laulau, Saipan . . . . . . AA 3. Classification of mass wasting . . . . . . . . . .. . . . . . . . . 27 4. Site comparison summary . . . . . . . . . . . ..... . . . . . . . . AA 5. Temperature and salinity at the listed depths with corresponding calculated density (Nov. 4, 1982) . . . . . . . . . . . . . . . . . AA 6. Checklist of vegetation by site . . . . . . . . . . . . . . . . . . AA 7. Checklist of terrestrial vertebrate fauna in the vicinity of Bahia Laulau . . . . . . . . . . . . . . . . . . . . . . . . . . AA 8. Checklist of benthic algae and seagrasses at five sites in Bahia Laulau, Saipan, Nov. 1982 . . . . . . . . . . . . . . ... . . . . AA 9. Total number of planktonic organisms per sample, Nov. 198Z. . . . AA 9a. Total number of planktonic organisms 'per sample, Feb. 1983. . AA 9b. Total number of planktonic organisms per sample, May 1983 . . . AA 9c. Total number of planktonic organisms per sample, Sept. 1983 . AA 10. Species list of corals for Sites 1-4 in B ahia Laulau AA 11. Coral size distribution, frequency, relative frequency, density, relative density, percent of substrate coverage, relative percent of substrate coverage and importance value for Sites 2, 3 and 4 in Bahia Laulau . . . . . . . . . . . . . . . . ... . . . ... . . AA 12. Conspicuous macroinvertebrates collected or observed in Bahia Laulau,Saipan, Nov. 3-7 1982 . . . . . . . . . . ... . . . .. . . AA 13. Fish species observed at Bahia Laulau, Saipan, Nov. 3-7, 1982 AA 14. Fish species observed on the reef flat at Sites 2 and 3, Bahia Laulau, Saipan, Nov. 3-7, 1982 . . . . . . . . . . . . . . .... . . AA 15.- Juvenile fishes observed during reconnaissance and transect dives at Bahia Laulau, Saipan, November 3 - 7, 1982 . . . . . AA 16. Fish densities calculated for different depths and general reef zones from line transect data compiled at Sites 2 and 3, Bahia Laulau, Saipan, Nov. 3-7, 1982 . . . . . . . . . . . . . . . . . . AA v Table Page 17. Tish densities calculated for different substrate categories from line transect data compiled at Sites 2 and 3, Bahia Laulau, Saipan, Nov. 3-7, 1982 . . . . . . . . . .. . . . . . . . . . . . . AA 18. Nations and territories with thermal resource (mean) annual L, T 200 C @ 1000m depth within 200 nautical miles EEZ . . .. . . . . . 140 19. Oceanographic resource paramaters . . . . . . . . . . . . . . . 141 NOTE: APPENDIX A (AA) Vi LIST OF PLATES Plate Page 1. View from Puntan Hagman looking down at Site the potential site for the OTEC facility . . . . . . . . . . .... . . . . . . . . . AB 2. View from seaward looking in at the'potential OTEC site . . . . . . AB 3. One of the numerous sand channels which run perpendicular out from Site 1 . . . . . . . . . . . . . . . . . .... . . . . . . . . . AB 4. The seaward slope just offshore of Site 1 . . . . . . . . . . . . . AB 5. Site la looking north across the reef flat to the@sand beaches along the shore . . . . . . . . . . . . . . . . . . . . . . . . . . AB 6. Typical coral formations found at a depth of 25 ft at Site la . . . AB 7. Site 2 looking southeast across Bahia Laulau . . . . . . . . . . . AB 8. Typical coral coverage at Site 2 taken at a depth of 30 ft . . . . . AB 9. Site 3 looking southeast acro-ss Bahia Laulau . . . . . . .. . . . . AB 10. Typical underwater view taken at a depth of 40 ft at Site 3 AB 11. Looking south across Bahia Laulau to Site 4 . . . . . . . . AB 12. Underwater view of Site 4 taken at a depth of 50 f eet . . . . . . . AB Appendix B (AB) S-1 SUMMARY OF FINDINGS I. HISTORIC INFORMATION Historically, Bahia Laulau affords one o f the better o pp or tunities to examine ancient Chamorro villages, latte stones, fishing areas: and burial grounds. Two major ancient historic sites exist in !the 'vicinity of Bahia Laulau where numerous artifacts have been unearthed. Additionally, the area was used for Japanese and U.S. military purposes during',the war as a lee-shore anchorage, military staging site and oil depot. Remn ants of mili- tary structures can still be seen in the area. II. PHYSIOGRAPHY AND SHORELINE SITE DESCRIPTIONS The immediate coastal region within Bahia Laulau is variable and includes low wooded terraces of limesand, recently raised limestone deposits, steep slopes, cliffs and headlands of both older raised limestone and volcanic -rocks. '.Fringing reef platforms of various widths and narrow beaches intermittently border the shoreline. Site 1. is located along the rugged northeast coastline @pproximately 800 meters (m) .(2,625 ft) west of Hagman Point in a small embayment. A steep volcanic slope forms the northern shoreline and a sheer lime Stone cliff with a deep concave notch cut at sea level-forms the western shoreline,. Site 1'a is located in a protected part of the bay appro .ximately 400 m (1,312 ft) northwest of Bapot Point and a narrow subtidal fringing reef platform borders the shore. Intermittently, the cliff face is undercut or notched just above the reef platform. Sites 2 and 3 are similar in that they are protected from northeast tradewinds and waves and are located in the vicinity of Trinchera Beach where a relatively wide intertidal fringing reef platform borders the shore. S-2. Bioclastic beach deposits, gravel and reef rubble form a narrow sandy beach along the shoreline. Site 4 is located 1.1 kilometers (0.7 miles) nor thwest of Dandan Point and is exposed to heavy tradewinds and wave assault. Low cliffs of Marianas limestone form the shoreline. A narrow fringing reef platform borders the shoreline at this site. III. GEOLOGY Geologically, Bahia Laulau is indented about half-way into the island perpendicular to the prevailing northeast- southeast trend of the major rock units and topographic features. Thus, it provides a cross-section along which most of the major rock formations and' many of the structures, soils and landforms can be viewed and studied. Site 1 is a very unique and scenic location. There is great geol.ogic diversity, extreme instability of onshore slopes and probably instability offshore due to major faults in the area. There is extreme wave vulnerability to cliffs and headlands, no surface water, fractured and permeable bedrock and a small manganese deposit. Both Sites 2 and 3 are recreational areas with relatively stable slopes and coastline. Both sites are vulnerable to typhoon swells and flash flooding. Alluvial processes present few sedimentation or drainage problems. However, subsurface porosity may present general construction problems. Site 4 is an excellent scenic location with a spectacular v,iew of the entire bay and Hagman Point. The area is quite stable and the coastline generally protected from typhoon-driven waves. There are no streams due to a highly porous substrate. S-3 For major on-shore construction of an OTEC facility, Site 4 is the most suitable in that it exhibits the fewest unfavorable geologic constraints. Site 1 is the least favorable construction site since" it exhibits the most unfavor- able geologic conditions. However, all sites have an abundance. :o*f limestone bedrock which is notorious for stibsurface permeability and porosity and tends to make it less than favorable for construction from the 'g6ologic point of view. IV. PHYSICAL PARAMETERS A. Depth and Temperature Bahia Laulau is a deep bay approximately 731 m (2, 400 ft) :at the deepest point. on a line between Hagman Point and Naftan Point. Slightly deeper:depths (823-914 m, 2,700-3,000 ft) exist 1.6 miles of f shore on a line 1650 (SSE) of the proposed OTEC site on Hagman, Point*.. These depths represent. possibly the most significant potential OTEC resoi@rc e in the world that close to shore. ',Temperatures offshore of the proposed OTEC- site@ appear to follow a well defined profile typical in the Western Pacific, 1.e.,@a Warm, well mixed surface la!''er of nearly constant temperature, a thermocline region where Y. temperature declines with increasing depth and a deep cold layer. Temperature decreased from 28.40 C at the surface to 22 k50 C at 229 m (751 ft). Between 229 m and 457 m (751-1500 ft) the tempe rature decreased to 7.40 C. Temperatures at 525 and 550 m (1,723 and 1800 ft) were extrapolated to be 6.40 C and 4.40 C respectively. B. Currents There is an overall circular current pattern which, exists in Bahia Laulau. A large volume of water enters the southern portion of the bay traveling along the inside contours until it exits at the northeastern opening. It seems that the majority of the water enters the bay from the S-4 northeast (prevailing wind direction) and splits apart. at Dandan Point in the southern part of the bay. This forms a rather consistent and strong clockwise water pattern within the center of Bahia Lau*lau. The leading edge of this water mass moves along or near the 100 fathom contour eventually emerging at the northern part of the bay at Hagman Point. Here it enters deeper water and/or merges with the overall water mass moving southeast. Inside the 100 fathom contour the near-shore water circulation pattern is much more complex and seasonally variable. It is influenced more by the prevailing winds and seas. Data suggest that this current runs counter to the deeper water circulation by following the shoreline. Several small eddies also form in more enclosed areas.* The inshore (reef-flat) current pattern is typical of any reef flat that is influenced by winds and tidal changes. During flood or ebb tides water tends to move towards a channel, cut or low area in the reef. This strong tidal flow usually overpowers the wind-driven' water movement unless they happen to be in similar directions. C. Water Quality Water quality within the bay is generally excellent. Ten near-shore water samples were evaluated for total and fecal coliform. Samples taken near the northern end of the bay suggest moderately polluted : conditions which can be traced to ranches in the vicinity. Most likely, farm animal wastes are being washed down to the bay where total coliform -counts show up extremely high. These conditions are not drastic at any time but are more severe than normal conditions following heavy rains. V. TERRESTRIAL FLORA AND FAUNA A. Flora Sixty-four species of terrestrial plants were identified during this survey. All major botanical communities, limestone forests, beach strand, S-5 savannah and modified forest are represented in Bahia La ulau. Diversity and species composition of vegetation at Sites 2 and 3 are similar,.: this being the only major similarity between the four sites examined. Flora at Sites 1 and 4 is unique compar, ed to Sites 2 and :3. Species composition is low due to intense environmental pressures, high winds and surf, salt air and rugged terrain. The ground is.. lar:gely porous limestone which quickly drains all water well:below the.surface'. Compared to Sites 2 and 3 both Sites 1 and 4 are depauperate: although:a number of different forms do quite well in the adverse conditions. Sites 2 and 3 are protected from harsh. environmental: pressures' which appears to allow for greater diversity. This is. also- the' site of lush limestone. forests located in isolated gullies and/or. steep 'slopes and clif f s. Pemphis acidula (Nigas) is abundant near the ocean. Sites 2 and 3 also include a ravine community of numerous valleys and gullies. The flora of this community is similar to that found in the limestone forest with a few plants that inhabit wetter areas ,since*,@water collects in (Pago), these ravi'es. One can always find Hibiscus tiliaceus (hibiscus) Cycas circ'inalis (cycad) (Fadang), Areca cat*hecu (bete-l-nut -palm) (Pugua Machena), Ficus prolixa (banyan) (Nana), several lianas and numerous epiphytes . such as ferns. Flora. at Site 4 appears to be the most highly modified within the Bahia Laulau. region. The area is dominated by a thick cover' of Leucaena leucocephala (tangantangan). Pemphis acidula (Nigas) a s'crub-like tree is found in a narrow band along the shoreline with gnarled trunks and twisted roots embedded in the limestone. A few small shrubs stand out here and there but not in great numbers. S-6 Between the rugged coastline vegetation and the thick tangantangan cover is a narrow remnant of a limestone forest. This entire area was most likely a vast limestone forest which stretched from: Dandan Point to Unai Laulau. Beach strand flora is taken to mean those plants most often found growing in the immediate vicinity of the sea. Most of these plants can be found elsewhere on Saipan, however, not as a dominant form like on the strand. B . Fauna Birds represented the most abundant type of fauna in the vicinity of Bahia Laulau. A total of 28 species were observed out of 34 species expected to occur in the entire area. All the sites were similar in total* number with. the exception of Site 4 where only 13 species were observed. The most abundant bird species encountered at the four sites include the Fantail. (Chichirika), White-eye (Nossak), Philippine Turtle-dove (Paluman Senesa), Sparrow (Gaga Pale') and Noddy Tern (Fahang). Common species for the bay area include the Bittern (Kakkag), Kingfisher (Sihig), Cardinal Honeyeater (Egigi), Golden Plover (Dulili), Starling (Sali),. White Tern (Chunge) and the Reef Heron (Chuchuko). A number of other vertebrates were observed or are* expected to occur in the Bahia Laulau area and these include the following: Three species of rats; Rattus norvegicus (Norway rat), Rattus rattus: (roof rat) and Rattus exulans (Polynesian rat); Mus muscuIns (common mouse); Suncus murinus (common shrew); Canis familiaris (common dog); Felis catus (common cat) Cervus unicolor mariannus (Sambar deer); Pteropus mariannus (Marianas fruit bat); Emoia sp (skink); Emoia cyanura (green-tailed skink); S-7 Anolis carolinensis (anole); Varanus indicus (monitor lizard) and Bufo marinus: (marine toad). VI. MARINE FLORA AND FAUNA A. Marine Plants Sixty-nine species of marine algae representing four, divisions were recorded from Bahia Laulau. In addition, one species of ..seagrdss, Enhalus acoroides, was recorded. Two narrow fringing reefs- (Sites 2@ ;and 3), one reef margin and reef face (Site 2), three shallow submarine. ier'races@ (Sites la, 2 and 3): and two deeper submarine terraces (Sites 1 and 4) were investigated. A range of. habitats including sand floors, :.reef flat. holes, cryptic overhangs, vertical walls and limestone terraces were present at the various, Sites. Site 1 is considered extremely depauperate due to the harsh conditions of seas and surf. Site la is a calm and quiet 'b@Ly with luxurient marine lif e. In general, the variable terrain of Site 2 provided numerous types of @.habitats for algal species. Site 3 is comparible ,to Site 2. The algal community at Site 4 is remarkably similar to Site 2 though fewer species were recorded. Each of the five sites examined in Bahia Laulau pr esented somewhat different algal communities, largely a function of exposure.' to the fetch of the open sea and coastal topography. Sites 1 and 4 exp erience the most regular and severe disturbances due to their direct exposure to windward ground swells. Site la is the most protected and Site's 2 and 3 are seasonally variable. B. Plankton Analysis of plankton samples for all sites indicate that Sites 1, 3 and 4 had the lowest mean numbers of species with 12, 11 and 12 S-8 respectively. Site 2 had the greatest species diversity with an average of 18 species per tow. In terms of total planktonic organisms per tow Site 4 averaged 1,506, followed by Site 3 (1,201), Site 2 067) and Site 1 (587). These results generally support what would be expected when looking at the current patterns and lack of a reef flat area along the cliffs out to Puntan Hagman. Sites 2, 3 and 4 (particularly Sites 2 and 3) are expected to be rich in plankton considering the current patterns, eddies, shallow areas and extensive reef areas present. C. Corals Ninety-eight species of corals representing 34 genera were recorded from the five study sites along the Bahia Laulau embayment. Considerable variation occured in species richness, size distribution, frequency Of` occurence, density and percentage of substrate coverage between the five sites and around the various zones discriminated at each site. One of the most noticeable aspects of the coral communities studied at the five sites in Bahia Laulau is their unequal distribution from the inner reef-flat platform to the 10 m (33 ft) depth contour on the fore-reef slope. Some reef zones have no corals at all while other areas support communities ranging from a few widely scattered colonies and species (reef-flat platform at Sites 2 and 3) to regions where the substrate is dominated by::'a relatively rich diversity of species (fore-reef slope at Site 2). Much of the regional variation found in the community structure of corals on the reef flat platform zones is.attributable to exposed platforms during low spring tides. Surface coverage on non-scoured substrates at Site 1 was estimated to range from 10-30 percent. Predominate coral species include seven in the family Pocilloporidae, ten in the family Acroporidae and nine in the family Faviidae. Corals from Site 1 that were not observed at other sites in Bahia S-9 Laulau include Pocillopora ankeli, Scapophyllia cylindrica and Stylaster profundi orus. p The only significant deposits of sediments consisted of poorly sorted mixtures. of sand, gravel and rubble in larger holes, troughs and depress- ions throughout the bay. D. Macroinvertebrates Conspicuous macroinvertebrates were collected at four 'coastal sites in Bahia Laulau. Gastropods were the most commonly collected: macroinverte- brates totaling 88 species. Among them, 22 species belong to the f amily Conidae, ten to the family Muricidae, nine to the f amily :M-i:tridae and' seven to the family. Cypraeidae. Nine species of bivalves were collected. Only two species, Astraea rhodostoma and Vasum turbinellas, we're. collected at all sites. Twelve echinoderm species were observed during' .@the study. The Crown-of thorns starfish (Acanthaster planci) was conspicuous at all sites and were observed in greater than average numbers. The reef flats of Sites 2 and 3 were more @'similar to one another than those:.of Sites 1, la and 4. The intertidal zones Were: similar to each other. In', summary, the conspicuous macroinvert ebrates: collected and observed represent a typical reef and embayment for a .southern Marianas Island. Although not observed during this study, the ,Spiny lobster is known to.be a significant resource of Bahia Laulau. They are regularly caught by divers along the reef front and on the reef flat. E. Fishes The fish community in Bahia Laulau down to 21 m (70 ft) is fairly diverse and appears to be in a relatively healthy state. This, and the wide range of habitats found there, makes it a potential site for ecological studies on reef fish. Many important spe cies of food fishes are present and the S-10 igh. The replenishment potential for recreational and subsistence fishing is hi of harvested food species should not be a problem since the bay is so large and since during most of the year much of it is made inaccessible to fishing by rough seas. The remote regions of the bay should be excellent sources of new recruits for the more heavily fished areas. Although Bahia Laulau represents a significant recreational and subsistence fishery for the island, preliminary data provides no real basis for the support of an intensive commercial fishery. It is generally considered by local fishermen that fish populations, close to the reef flats have declined in recent years due to heavy fishing. F. Marine Turtles and Mammals A total of 9 sea turtles were observed during the study., More turtles were observed on the surface at Sites 1 and 4 than at other Sites on the surface or underwater. Two green sea turtles (Chelonia mydas) and one hawksbill (Eretmochelys imbricata) were observed on the surface from our observation post above Site 1. Three green sea turtles (Chelonia mydas) were observed floating off Site 4 from our quarry observation post. One each of the green and hawksbill turtles were observed underwater at Site 2 and one hawksbill at Site 3. Turtle nesting has been observed in the past at afew isolaied beaches which occur within Bahia Laulau. However, no nesting' sites were observed during this study. Sites of previous nests were noted at beaches below the airport quarry (Site 4). In the past the majority of sitings occured in the vicinity of Hagman and Naftan Points, these areas being more protected and isolated. Porpoise, a marine mammal, are known to occur in Bahia Laulau. Small schools of an unidentified variety were observed on two field visits (Feb. S-11 and May 1983). It is likely that porpoise use the bay as a feeding site and for protection during migration. There did 'not appear to be resident population of porpoise in the bay. Whale sitings have never been confirmed in the Bahia Laulau area and none were observed during this study. VII. OTEC DEVELOPMENT The CNMI government recognizes the importance of `OTEC develop- ment as a part of its renewable energy program to reduce its dependence on imported fossil fuels. The Bahia Laulau OTEC site represents one of Ahe`@best thermal resources for OTEC in the world with an average mon thly temperature dif f erential between warm surface and cold deep ocean waters.' exceeding 210 C at 30.5. m (1,000 ft). Data indicate that a year-round temperature dif f ereptial over 210 C exists at a depth of 550 m .(1804 :..ft) :and a 230 C diff erential can be obtained at a depth of 900 m (2,953 ft)-., The competing ocean uses on which OTEC facilitie:�,'may be expected to impact. are fisheries, port development, navigation-,- and recreation. However, '@'the location of any OTEC facility can be plaiin'ed to cause a minimum of interference with shipping and port development. The major ocean uses that would be affected by the Bahia Laulau,.OTEC facility are fisheries and recreation. The effect of OTEC development on marine waters. relates to the displacement of'warm, shallow water with cold, deep water'. resulting in the modification of temperature, salinity, density, dissolved oxygen, nutrients, carbonates and particulates. Known as "artificial upwelling" it has the potential to increase fish populations with corresponding high yields in productivity. However, it can also modify the near-shore environment negatively depending on the placement of the outfall pipe in proximity to the shore. S-12 VIII. GENERAL DISCUSSIONS A. Physical and Biological Resources Bahia Laulau is resource rich in many ways. It is Saipan's largest natural bay offering protection and anchorage for small and large vessels. Although it is located on the windward side of Saipan, much of the bay is protected from direct wave assault and oceanic current patterns. A well developed and highly diverse coral reef fringes most of the inner part of the bay. Those areas of the bay not protected still have a highly diverse reef terrace. This reef provides numerous nich6s for an incredible array of marine life from the smallest to the largest forms. The reefs p rovide further protection for animals such as the green sea' turtle which is known to nest on the numerous small beaches scattered throughout the bay. The bay is rich as a fishery resource supported by a diversified plankton population. Local fishermen frequent the bay for sport and subsistence fishing. Throw-net fishermen and spear-fishermen consistently utilize the bay and can be seen out on the bay most days of the year. Plankton samples indicate a healthy population of fish eggs and larvae which support the future subsistence fisheries of the bay. A manganese deposit located on the Hagman 'Point clif:fline above Forbidden Island is a resource which was developed by the Japanese durin 9 the war. It appears that the manganese was stockpiled f r eventual removal. The extent of the deposit is unknown. Further studie s would be required to determine the exact quantity and quality and potential of this resource. B. Recreational. Resources Local residents utilize the bay for a number of purposes. Some of these include fishing, boating, swimming and picnicing. In addition to local S-13 residents, tourists are now beginning to utilize the bay a s well. On any day a number of scuba divers can be seen entering the water in the vicinity of the narrow cut at Bapot Beach. Tourists are also using the bay for sunbathing, picnicing and swimming. C. Resource Degradation The reef within Bahia Laulau represents a major resou rce to the residents of Saipan particularly in terms of a subsistence food sol'urce., Some damage to this resource is presently underway as a result,of an increase in Acanthaster planci (crown -of-thorn s starfish) coral kills 'and '':sedimentation from drainage channels along the beach. The impact to :recreational uses within Bahia Laulau is a potential problem since, both, Sedimentation and starfish kill reefs. Sedimentation also pollutes the near'-shore water by dumping dirt and micro-organisms like coliform into'it. Conditions like these are not healthy for swimmers, divers, fishermen or sun bathers. D. Tinique Areas and Features Aesthetically, Bahia Laulau represents some of the: best scenery and beauty which Saipan has to offer. The lagoon is deep@ blue, reefs colorful and diverse, white sand beaches, rocky outcrops upon, -which breakers crash, steep cliffs, caverns, underwater caves, dense tropical vegetation and gently sloping fertile soil upland from the shoreline. Overlooking the bay is one of Saipan's best restaurants which commands an exceptional view. It is likely that Bahia Laulau will experience intensive pressure for further development because of its natural beauty. Hagman Point represents the major unique feature of Bahia Laulau with steep cliffs, isolated coves and beautiful yet rugged terrain. Forbidden Island, aptly named and separated from the main land form by a narrow channel, is the major promontory of the bay. Other unique areas include S-14, the protected cove near Bapot Beach where an extreme ly well developed fringing coral reef exists. Both Bapot Beach an d Trinchera Beach are unique areas and represent the best beaches in B ahia Laulau. The reef flats and reef margins are very well developed and are utilized by fishermen and skin and scuba divers alike. Two or three small.. isolated beaches exist between Trinchera Beach and Dandan Point and are unique since they are known to be turtle nesting sites. The bay itself is the largest natural bay on Saipan and one of the largest in the Marianas Archipelago. Deep, cold water near shore represents a unique feature for potential OTEC development. INTRODUCTION The Physical Planning Office of the Government of the Northern Mariana Islands issued a request for proposals for a Marine Biological: and Physical Survey of Bahia Laulau, Saipan, (Figures 1 and 2) during 'May.' 1982. The firm of Pacific Basin Environmental Consultants, Inc, '(P.B EG@ submitted a proposal to the' CNMI Planning Office on June 4, 1982P and .'was' awarded the contract on June 28, 1982. Final contract documents, were -signed.by all parties on September 10, 1982. This project is funded un der. a grant from th& U..S. Department of Commerce, Office of Coastal' Zone Management (CZM), Coastal Energy Impact Program (CEIP). The study of Bahia Laulau was initiated because @a potential site for an Ocean Thermal Energy Conversion (OTEC) plant had been -chosen along the southern', edge of Puntan Hagman (Hagman Point) in north Bahia Laulau (Figure 2)., Since very limited biological and physical data exists for Bahia Laulau, this study would provide baseline data necessary for planners and others to base major decisions concerning a potential OTEIC plant or other future plans for the bay. SCOPE OF WORK The scope of work was finalized with input from PBEC, Commonwealth of the Northern, Mariana Islands (CNMI) Planning Office, , CNMI Fish and Wildlife Division of the Department of Natural Resources and the Coastal Resources Management (CRM) Office. The scope included the following tasks: FARALLON DE PAJAROS- - WAUG ASUNCIO N. .AGRIMAN PAGAN -@ ALAWAGAN GUGUAN SARIGAN ZEALANDIA BANK N ANATAHAN FARALLON DE MADINILLA. TINIANfj SAIPAN *AGUIJAN ROTA- JGUAU (USA) NORTHERN MARIANA ISLANDS NO SCALE SAN ROQUE TANAPAG PA CIFIC 0 C E A N GARAPAN .ISLAND.OF SAIPAN 1 0 1 2 SUSUPE SCALE IN.MILES CHALAN AN INCENTE KANOA GLAKE BAHIA SUSUPE LAULAU SAN ANTONIO SAIPAN INTERNATIONAL IRPORT Figure 1. PROJECT LOCATION MAP ss* 45' 13a* 46' t ukl Yj 10 r it \j, SO' me t- r9 & \N ,%\\ -3, % 14 IN It 01. 1 a30 )a 14 to - 53 )0111 00 Wc 3, 47 61 4) :is FL 00 61 406 '10 ...... 94 45 7 it 2 36 so goo.,545 gg ISO go 3 Is# S? 74160 goo,11, 91 61 )4 )s v 173 110--- too. 50 4S 16 46 195 100 ?o !21 30 ), ..5".. 1. il... I i 145 I's ISO 2 S."', : 6, R9 too -57 ": ifI do 90 710 ISO 150 10 if 71 1,!", IS; 200 too 0 3S s4 20 10 29 34 95" 195 S 72 4) 51 as," 200 1110 155 200 290 710 258 .95 260 49 t 1 16 143 Igo 48 '00 700 165 300 ),0 V-41 10 2 J.'O goo 23S -44 049 1. 741 790 56 190 095 300 85 '78 '91 , 1;0 200,.740 ')$a 3. gg"I is 57a,: 700, .19Q -170 07 .2b, 2-15 165 41 IS go Iss 2,0 48 ST, 1 11 06-i9o )do 90 1-0 '110 220 00 3. -d\ 13' as 42 ?a )fib ..0 170 60 220 %a go 271M J1,4 5 too.. 145 3110 32 go goo do ]9 49 15 oo@ 245 IS IOU IN a33 V) 5, 6. 4,. 15 113 1) I@o 105 4,0 it, )so 'a 3' 31 9f 175 '95 J!@ hf IS !4 29 ion a., '58 Figure 2. Bahia Laulau showin 190! the-proposed OTEC f "0 -Az five study s 4 SCOPE OF WORK 1. Compile complete historical data base of physical,, chemical and biological conditions of Bahia Laulau. 2. Conduct field surveys of all major flora and fauna of Bahia Laulau Count and identify corals, fishes, algae, seagrass, invertebrates, sea turtles and mammals. 3. Conduct quarterly field surveys of abundance and distribution of eggs, larvae and juvenile fishes and other significant marine resources to identify important breeding and nursery areas. 4. Define physical characteristics of submarine lands and reef structures. 5. Through quarterly surveys, define physical characteristics of shallow water including current speed and direction, temperature gradients and salinity. 6. Conduct a deep water temperature profile' at depths of 750, 1,000, 1,250 and 1,500 feet off site of proposed OTEC plant. 7. Conduct a field survey of Vackshore lands to identify terrestrial flora and fauna and physical characteristics. 8. Define resources at Bahia Laulau and identify degradation of same as a result of destructive fishery practices, erosion, sedimentation, crown-of thorns starfish (Acanthaster planci), runoff, fecal coliform, etc. 9. Identify historical resources, pristine areas, unusual oceanographic features and altered shorelines. 10. Prepare three (3) quarterly data reports due 30 'days after completion of each of the first three surveys (3 copies) and a final report to include text, data, maps, charts, photos, tables and any other methods necessary to convey the findings. All species will be id'entified by scientific, Chamorro and English names. Place names will conform with the U.S. Board of Geographical Names. Draft report di4e 30 days after completion of final survey. 5 SURVEY TEAM, The survey team assembled for the Bahia Laulau project' by PBEC included.:personnel from the University of Guam (UOG) Marine Laboratory, Guam Division of Aquatic and Wildlife Resources, University of California at Berkeley. and the University of Maryland as well as a local field assistant from Saipan. The following is a list of team members with thei,@r -primary and secondary responsibilities. Michael. J. Wilder, PBEC Principal Investigator; terre'stria'l, flora; fathometer profiles and deep water temperatures; report preparation. Ronald P. Strong, PBEC Project Coordinator; terrestrial;, fauna; assist in field work; current studies; photography; report preparation. Lucius', Elderedge, UOG Professor Checklist and evaluation of -marine invertebrates. Ann Kitalong, M.S. Candidate at UOG Marine Lab Analysis of quarterly plankton -samples. Michael Molina, Guam Division of Aquatic and Wildlife Fisheries Biologi'@st - Checklist and transect analysis of the @fishes of Bahia Laulau; data on sea turtles and mammals. Richard Randall, UOG Associate Professor - Checklist and: analysis of the corals; reef physiography; assist with marine geology- Galt Siegrist, University of Maryland Professor - Evaluation of the marine and terrestrial geology of the Bay; sediment analysis; geological re- source evaluation. Alicia Siegrist - assist with the geological resources and resource economics. Jeanine Stojkovich, U.C. Berkeley PH.D. Candidate - Checklist and evalua- tion of marine plants; general field assistance. Ben Concepcion, Owner of Water Sports, Inc., Saipan Provide boat and diving equipment for the team; assist in diving operations and. logistics; assist with plankton tows and current studies;: provide information on recreational and commercial uses of Bahia Laulau.: 7 ACKNOWLEDGEMENTS Pacific Basin Environmental Consultants, "Inc., would like to' thank the following*. individuals and organizations for their assistance and help in planning and carrying out the Bahia Laulau study: George Chan, David Liem, Elizabeth Udui, George Ehlers 'and the entire staff from the Physical Planning/Energy Of fice Manny Sablan, Paul Benoit, Tami Grove, Debby Knutson, Ben Bland and. Ben Aldan of the Coastal Resources Management Of fice, Representative Ben Sablan, Rufo Lujan, Pat Bryan,@.,Tom Lemke and Thane Pratt of the Fish and Wildlife Division of the Department of Natural Resources Ivan:,Groom of Northern Islands Company 8 GENERAL METHODS AND PROCEDURES The Bahia Laulau field evaluations were design ed to be completed dur- ing the initial survey and/or quarterly over a period of one year. The initial survey employed the entire team and covered all aspects of the scope of work. The other three quarterly surveys investigated the currents (reef-flat and offshore) and the planktonic community of the bay, two para- meters that vary with time and season. Additional data were collected quarterly to supplement the initial survey and included information on the birds, turtles, marine mammals, Acanthaster planci concentrations, fishes, plankton, currents, wind patterns and nearsh'ore water. chemistry. A total of four survey sites were selected along Bahia Laulau after discussions with the Planning Office, CRM and Fish and Wildlife offi,ces. The four sites represent different habitat and reef types and vary considerably in their exposure to wave assault. The four sites, along with an intermediate site (1a) that was added later, are shown in Figure 2. Underwater surveys were conducted from the shore using snorkeling and/or scuba equipment at Sites 2 and 3 (reef-flat only) . All other sites were investigated by snorkeling and scuba from a zodiac inflatable boat and the M.V. Bahia Laulau. Various methods were used by. the individual scien- tists including timed swims, random counts, depth/timed transects'. and placed 50 meter (m) (164 feet (ft)) transects. Please refer to the. individual sections for detailed methodologies. 9 HISTORICAL INFORMATION INTRODUCTION AND GENERAL. BACKGROUND Historical information contained in this section is a compilation of data excerpted from five separate research papers since the middle of this century. For. the sake of uniformity the majority of, this historical information is taken directly from existing reports. These data' present an accurate picture of historical significance in the vici B'' ul nity:o, ahia La au to date. The Mariana Islands are well known to insular geologists for the: classic raised coral reef structure of many of the islands. Saipan "falls into this categor .y with only minor deposits of volcanic rock exposed in a few of the deeply'. eroded stream beds in the northwest part of the island. The! larger islands are thought to have emerged f rom the ocean no earlier than Late Eocene. Soil formation and the introduction of terrestrial flora and1fauna presumably proceeded from the time of emergence. The, :@Bahia Laulau formation is thought to be the result' of gradual loss of land through sea and land slides into the precipitous. Marianas Trench which runs parallel to the Marianas on their eastern flank.. Accurate historical information regarding Bahia Laulau prior to World War II is. @sketchy and only a few references exist. Howe ver, in 1858 a British Royal Naval Officer by the name of Mr. Harvey., aboard the HMS Magicienne, surveyed and sounded the bay and named it'Magicienne Bay, which still stands as its official designation. The Chamorros refer to it as Bahia Laulau which may derive from the Chamorro word laolao, meaning "shaking" or "trembling" a generic word that can apply to the earth's movement during tectonic disruptions. It is known now that a2, major fault 10 line transverses central Bahia Laulau from Naftan point 'to a small ravine near Puntan Hagman. a Historically, work in the vicinity of Bahia Laulau has had two major thrusts; archaeology for the sake of general historical knowledge of the people and customs and military significance for the sake of war strategy. p METHODS Historical information regarding Bahia Laulau was* taken from a number of references but relies mostly on Spoehr (1959) , Takayama and Egami (1971), Takayama and Intoh (1976), Reinman *(1977) amd Thompson (1977). Field visits to the Bahia Laulau archaeological sites were undertaken to examine them first hand. These field excursions included the upper Laulau Bay Coastal Access Zone, Laulau Site, Bapot Site and the Laulau Rock Shelter. Field observations were noted and compared to findings in. the literature. RESULTS Laulau Bay Archeological Site Given a fair amount of superficial and incidental. knowledge about the sites of the windward (eastern) coast of Saipan, a 'zone was defined for intensive archeological survey (Thompson, 1977). This survey was designated The Upper Laulau Bay Coastal Access Zone and it was: defined on the basis of reef configuration, shoreline topography, soils, su rface slope and continuity of vegetative cover (Fig. 3a). The.reef configuration concerned is the development creating.the lagoon in the upper portion of the bay, an area protected from the full fo rce of the northeast swell by th& Hagman prominence to the east. Shoreline topography is that of a gradual slope which rises up from the lagoon in broad beach areas: at Unai Bapot, Unai Laulau and at the small beach in between the two (Fig. 3b). Up the coast from Unai Bapot, the 145- 50' SABANETA PT. MA I G 0. FAHANG WT NAPAG N MUCHOT PT. 5 3 LAULAU S 4@ Blockh Ous 0 BO Loulou Beach 7a LAULAU 15*1,/ OLEA1 KATAN 15,10, - SkJSJPE LAKE 7b 3 PT. 30" - MAGIC II.L' Ht.VE CHALAN OSUSUPE 15,9, - (LAULAU RA KANOA HANGMAN PT. SLITO MAGICIENNE BAY AN ANTON110 '7) 7c DANDAN PT. AGINGA Fic; .3b.'Nla Bay, @@ipan showing Joe gicienn PT. CAPE OBIAN J, NAFTAN PT. f45- 50' Fro.3a, Principal archaeological sites of Saipan. Ntimbcrs on map rercr to rql- Illwing sites: 1, Objan; 2, Laulau; 3, Bapot; 4, As-f-co; 5,'rilofofo; 6 Farlunchulujan; 7a Olcai- 7b Chalan Xija- 7c: Chalan Piao- 8 Chilan Calcite. 12. beach gives way to limestone cliffs. About 500 m (1,@640 ft) further towards Hagman the lagoon edge meets the shoreline and ocean waves pound directly onto the cliffs of the shore. There is a ravine at this reef terminus which is mainly washed clear of soil and artifacts. This ravine is a convenient upper limit for the zone. At the opposite end of the main lagoon formation is , the lower limit of Unai Laulau. Here a ravine opens out of the island and creates a well defined terminus to the beach. The lagoon continues some 400 m (1, 312 ft) down the coast from this point but become*s quite thin well before its terminus. The lower limit ravine just mentioned defines the terminus of the beach while the next ravine down the coast (in which the main road is situated) empties into the sea at the point where the lagoon terminates.. Inland, this ravine presents a heavily washed area that serves well as the lower limit of the zone. As with the upper area, the beach terminus is followed by a limestone*bluff and cliff formation. While direct access to the water is not impossible up-or down the coast from the area just defined, it is, in a word, inconvenient. The general impres sion was that sites were less common outside the zone and absent on certain heavily sloping surfaces. The inland limit of the zone i .s generally defined 'as the 6 .1-m (200 ft) elevation above mean sea level. There are broad plateaus inland of this elevation in the southern portion of the island, the area leading to the Hagman prominence above Bahia Laulau, the area inland of the coast between Puntan Nanasu and Puntan Tanke and across the northeast face of the upper tip of the island. The descent from the plateaus to the coast in the access zone usually consists of small escarpments or heavy slopes dropping quickly 13 to about 31 m (100 ft) where more gradual slopes are enc ountered leading to the beach. Excavations at Bahia Laulau The. following is a general location and -description of excavations at Bahia Laulau. The Laulau. site is located on the northwestern 'shore of the B ay on the east coast of Saipan (Fig. 3b). The site lies about 150 feet inland from the beach and to the west is a harrow road that: runs around Magicienne Bay. The Laulau site is approximately 183 @m (@00 ft): long :and 61 m (200 ft) wide with its long dimension paralleling the 'shore*line. It is northwest of a massive, concrete Japanese blockhouse built on the bea:ch and commanding the bay. The Laulau site is a coastal one permitting the combination of good farmland with access to the resources of the sea. This site w :as, mostly undisturbed by military operations but 'was partially excavated' by the Japanese for military purposes. North. and east along the shores of Bahia Laulau .a, coastal terrace about 93*.t.n. (300 ft) wide upon which is found the Bapot: site. The soil is good and.there is reasonable access to reef and off shore' fis@h@ing. This area is the site'.O:f three clusters of Latte houses: Bapot I consists of two, Bapot II of four and Bapot III of five. All have been disturbed by defensive trenching by the Japanese military forces and a road also,. cuts across the former occupation area. Shards are distributed throughout the area. It is probable that the area once contained numerous house sites. Northwest of the site there are a series of limestone cliffs. A large limestone segment has fallen away from the cliff edge and forms a rock shelter. This is Laulau. Rock Shelter, a significant archeological find. The ground at the rock shelter is approximately 35 m (115 ft) above sea level. 14 From the rock shelter the terrain slopes gradually down'to the beach and the site is located on this sloping ground. Surface features of the site consist of scattered- @shards plus the remains of four latte houses; all badly disintegrated. Two latte houses are located at each end of the site. The four houses are in rough alignment. It is quite possible that other latte houses once existed, but have since disintegrated. At the time of excavation, some of the site was planted in maize, coconut palms and bananas. The rest was lying fallow in grass. According to Chamorro informants, the land has always been. hand-tilled. In Japanese times it was used for tobacco. Recently it was used primarily for growing maize. The beach at the point of the site is bordered by a' wide, fringing reef. As the location is on the tradewind side of the.island, the waters of Bahia Laulau are usually rough. In early times it would have been difficult to bring canoes of any size over the fringing reef; however, the 'reef fishing is excellent. At the Laulau site, two structures were excavated: House A, the southwestern most latte house; and the rock shelter. Military Significance In the 1950's both the U. S. Navy and Army Corps oi' Engineers undertook studies in Bahia Laulau for military purposes. Primarily, the military was interested in utilizing the bay as a landing site','. limited lee anchorage and oil depot. The majority of this information was. collected by the Army Corps of Engineers in their Military Geology of Saipan, Mariana Islands in three volumes: 1, Introduction and Engineering Aspects; II, Water Resources; and III, Beach and Terrain Analysis. The purpose of this survey was two-fold. The first was to collect scientific information through 15 a field study of major islands in the Pacific and the second' 'Was to publish this information in a form usable by the U. S. Armed Forces and Civil Administrators working on assignments in the islands. Since the war, a number of studies on a,wide variety of subjects have taken place in the Mariana Islands. Most of these studies were,'undertaken by the CNMI government to learn more about the islands for the purposes of development. Most of these studies are geological, arcifiae*ological or biological. 7 16 LITERATURE CITED Reinman, Fred M. 1977. An archaeological survey and preliminary test excavations on the island of Guam, Mariana Islands, 1965-1966. Misc. publication No.1, MARC, Univ. of Guam. Spoehr, Alexander. 1957. Marianas prehistory, archaeological survey and excavations on Saipan, Tinian and Rota. Fieldiana, Anthropology (48), Chicago National History Museum. Taka'yama, Jun and Michiko Intoh. 1976. Archaeological excavation of Latte Site (M-13), Rota in the Mariana Islands, Reports of Pacific archaeological survey No. 4. Tokai University Japan. Takayama, Jun and Tonoko Egami. 1971. Archaeology on Rota in the Mariana Islands. Preliminary report on the excavation of the Latte site (M-1). Reports on Pacific archaeological survey No. 1. Tokai University Japan. Thompson, Dean. 1977. Archaeological survey and test excavations along the leeward coast of Saipari, Mariana Islands. Part I. A survey of methods@ and procedures, Iowa City, Ms. 17 PHYSIOGRAPHY AND SHORELINE SITE DESCRIPT 10 NS INTRODUCTION The. immediate coastal region within the Laulau embayment is quite variable and includes low wooded terraces -of limesand,% recently raised limestone deposits and steep slopes, cliffs and headla nds of, b6th:older raised limestone and volcanic rocks. Fringing reef platforms of various widths and narrow beaches intermittently border the shoreline. METHODS Describing the shoreline features of each Site in. Bahia Laulau required literature search and field mapping. Prior to actual field 'evaluations, a composite;map was drawn from existing data and maps (Clou d 1959, Doan and Siegrest, 1979, Eldredge and Randall, 1980). These. maps,.were then taken into the: field and checked for accuracy. Four (4) sites. were chosen for detailed study. However, a fifth site (1a) was added for. iis uniqueness and because it. was a frequent rest spot between investigations :at other sites. All study: sites were evaluated on foot and offshore, :,by boat. Brief description''s of shoreline features at the five study sites -1ollow. Refer to Figures 4a and 4b for details. RESULTS Site .1 is located along the wave-assaulted northeast section of Bahia Laulau about 800 m (2,625 ft). west of Puntan Hagman in a* small angular enbayment wher e Mariana Limestone is in fault contact with volcanics of the Hagman formation. A steep volcanic slope forms the northern shoreline of the site and a sheer limest one cliff with a deep concave notch cut at sea level forms the western shoreline. Large blocks and boulders, presumably wedged out from the adjacent steep slopes and cliff face, buttress the 18 Ttd Tdca 100 - Tti - 100- -Ttd The SITE 1 SITE la 80 Qx Qmh 80- ;4 X@L 111, mi A E@@ - 60- Tti 60 5 aV@ Qmh 40 40- 4 Q a Qa The 2 0 20- Qrl 0 0 Soo 400 300 200 100 500 400 30rO 200 100 0 100 T h b SITE 2 80 Qp 60 Thb Thb 40 17 Tti 20 rb 0 600 500 400 300 200 190 0. 200 Tti > SITE Ttd 150 Qma -N@;` -'VF, Qma 100 F@' 50 Qta 1300 1200 i100 1000 900 800 700 600 500 400 300 200 100 0 100. SITE 4 80 - 11-@Qmm 60 Qta '6 40 Qta 30 0 7. 800 700 600 500 400 300 200 100 0 DISTANCE FROM SHORELa.\E IN 'IETERS A, Fi,-ure 4a. Profile of terrestrial sections for sites 1. la, 2. 3 and 4 at Bahia Laula-j. Refer to Table I for Rock Unit symbols. Rocky Shore Islet SITE 1 LEGEND 19. Reef Rock Sand, Gravel, and Rubble B o ul d e r s 10 meters Inner Slope J:fj2jZ orals 0 15 50 75 METERS ,Limestone Cliff SITE la High Tide Low Tide 10 meters Reef Flat Platform Zone Reef Forereef Slope marg in Zone Z on e 75 f5 5'0 16o i5o METERS Beach Deposits SITE 2 ------------------------------------ SlOD-e- "-;c Forereef a 'i Submar4nr- T, Zones 10 e@ers Reef Flat Platform Zone Reef Margin Zone 0 25 5b METERS 75 100. 125 15C Beach Deposits I--- Raised Limestone SITE 3 For. R ef ereef Slope.Z.one Reef Flat Platform Zone M rgin Zone 10 meters 0 50 200 150 260 250 36t METERS J-1imestone Cliff Be.ach Depos imeston @ITE 4 Raised L Foreree,@ SloDe Zone Reef Flat Platform Zone Reef Margin 10 meters Zone rL 0 25 5'0 i'O 0 METERS Figure 4b Vertical profiles of Sites 1, la, 2, 3 and 4 at Bahia Laulau showing submarine topography, reef zones, water depth and relative 6istribution of corals and sediments. 20 shoreline and at a few places form small wave-washed islets a f ew meters from shore. Site la is located in a relatively protected section of Bahia Laulau approximately 400 m (1,312 ft) northwest of 'Puntan Bapot where a narrow subtidal fringing reef platform borders the shore. A low cliff, of Mariana Limestone buttressed with numerous blocks and boulders forms@ 'an irregular shoreline along the site. Intermittently, the cliff f ace is prominently undercut or notched just above reef platform level. Site 2, also somewhat protected from Northeast Tradewind wave assault, is located 450 m (1,476 ft) east of Trinchera where' a relatively wide intertidal fringing reef platform borders the shore. Beach deposits, composed mostly of bioclastic sand, gravel and rubble of reef origin, form a narrow band 'along the shoreline. The shoreline features at Site 3 are quite similar to those of Site 2 except for greater exposure to tradewind waves and a%'narrow band of recently emerged limestone (less than 1 m high) that separates bioclastic beach deposits from the intertidal fringing reef platform.@ Site 4-,, located 1.1 kilometers (0.7 miles) northwest of Puntan Dandan, is exposed to heavy tradewind wave assault. Low limestone cliffs of Mariana Limestone form the shoreline. Although extensive beach deposits are absent along the shoreline, a few small patches of bioclastic rubble have accumulated at, erosional reentry areas along the cliff face. A narrow fringing reef platform borders the shoreline at this site. CONCLUSIONS Sites I and 4 are the most unique and different of all five sites. Both are unprotected against heavy ocean swells and are, therefore, usually rough and dangerous in terms of currents and seas. 21 Sites 2 and 3 are quite similar although Site 2 is. slightly more protected from northeast tradewinds. Both have intertidal fringing reef platforms and bioclastic beach deposits. A narrow cut through the:' reef at Site 2 provides reasonable access to the bay. Site la is the most protected site since it is tucked in and away from prevailing winds and waves. It is more similar to Sites 2 and 3 than Sites 1 an d 4. 22 LITERATURE CITED Cloud, P. E. , Jr. 1959. Geology -of Saipan' Mariana Islands, Part 4, Submarine topography and shoalwater ecology. U. S. Geological Survey Pro *fessional Paper. 280-k, 84p. Doan, D.B., and Siegrest, H.G., Jr. 1979. Beaches:9 Coastal. environments and alternative sources of fine aggregate in the Northern Mariana Islands. Coastal Resources Management, Executive ' Office of the Governor, Commonwealth of the Northern Mariana -Islan S.' :108p. W Eldredge, L.G.-, and Randall, R.H. 1980. Atlas of: reefs and beaches of Saipan,' Tinian and Rota. Coastal Resources Mana4ement, Ex ,ecutive Office of the Governor, Commonwealth of the Northern Mariana Islands. 23. GEOLOGY INTRODUCTION Saipan exhibits the same high degree of geologic diversity and com- plexity that characterizes the other major islands in southern Marianas. A core of Eocene-Oligocene submarine volcanic and: volcanoclastic rocks, formed as the result of tectonic plate convergence, has been veneered with progressively younger sequences of shallow-water* limestones. Vertical tectonic adjustments of the island-arc system,, including net uplift, faulting and tilting, coupled with sea level fluctuations arising from Pleistocene glaciation cycles, have raised and terraced Saipan and the other "high" islands in the southern Marianas. Bahia Laulau is indented about half-way into the island perpendicular to the prevailing northeast- southwest trend of the major rock units and topo- graphic features (Figure 5). Thus, it provides a cross-section along which most of the major rock formations and many of the structures, soils and landforms can be viewed and studied. METHODS The goal of this study is to prepare geologic environmental: evaluations of four pre-selected onshore sites in Bahia Laulau where land'-use modi- fications have been suggested (Figure 6). In order to carry out this objective in 31 field days, hea reliance is vy: placed on supplementary sources, including earlier published 'maps, data, reports, '.,and on aerial photo interpretation. Seven field transects were required to sample, describe and evaluate the geologic materials in the vicinity of the four sites and to verify the air photo analysis. 24 145 0 40 -145*50'. 15.019 1501.01, Y -A PHILIPPINE SEA J PACIFIc@ OCEAN BAHIA LAULAU J LEGEND SHORELINE. FAULTS: Demonstrable, Inferred, SCALE 1:136,720* Concealed or 15005. Hypothetical 15CIO5 145040'11 145 050'.i Figure 5. Reference map of Saipan (after Cloud, et. al. , 1956). 1% % UN Al BAPOT @01 A A UNAI -B ;LAULAUI T, SIT rE r+ f A 0 (D En B r+ r+0 ,...v 0 SITE 3@ 0 0 6? En :.BAH I ALAULAU cr LEGEND,', Contour Line.j o%A Road Quarry Profile Line w UNAI Manganese DANDAN -77-1 4 Approximate Pa Location of Fi A gal % SITE 4:@ % -j A 26 Any new land-use activity requires some thought on possible environ- mental effects. Along Bahia Laulau eight:' geologic-relatedi factors or conditions were considered necessary to arrive at reasonable site 'evaluations and site-to-site comparisons. Rock Units: Distribution, thicknesses, stratigraphic position, .:structural and physical: properties. Rationale: The mineral composition, grain si ze geometry (texture) and fracture characteristics of a rock body place limits on, engineering and building applications. They control the type and thickness of soil 'cover, slope and terrain morphology, surface and groundwater': hydrology and economic. resource potential. In Table 1 (Appendix A) We,present a- list of the mapped units and a general summary of their importan't characteristics used for site evaluations (Modified from Cloud, et. al., 1956).. Soil Units: Distribution, thicknesses, composition and physical properties of mapped soil units. Rationale: Engineering properties of soils are. derived from their basic mine: r:al composition and thickness. Strength, sensitivity to vibration or excavation, compressability, erodability, permeability, sl@rink-swell poten- tial and ease of excavation must be considered in site studies. Table 2 (Appendix A) lists the major mapped soil units', around the sites of Bahia. Laulau and their important characteristics (Modified from McCracken., 1957). Slope and Stability: Slope stability is evaluated by estimating the "safety factor", defined as the ratio of resisting forces (usually shear strength of slope materials acting along potential slip planes) to driving forces (usually the weight of the slope material including vegetation and buildings). 27 Rationale: Forces are static; they change with time, earthquakes and planned and unplanned slope modification. There are many signs of historic, ongoing and potential slope instability around Bahia: Laulau; several of the latter could be catastrophic. Moreover, submarine. slope instability should not be overlooked at any site where underwater structures are planned. Table 3 presents a classification of the principal types of downhill movement or mass w asting (Keller, 1982). Where observed, they are noted on the profiles included with the site evaluations. Table 3. Classification of Mass Wasting. Type of Materials Movement Rock Soil Slides Slump Blocks Slump blocks (variable water Translation slide (Rotational slide content and rate Soil slip (planar) of movement) Falls Rock fall Soil fall Slow Rock creep Soil creep Flows Unconsolidated materials (saturated) Earthflow Mudflow (incl. submarine) Rapid Debris avalanche Complex Combinations of slides and flows. Geologic Hazards: Geologically-related conditions that can lead to' @loss of life and property. Rationale: 'Excluding slope instability already mentioned and the overall problem of earthquakes, danger from flooding must be considered the most serious geologic hazard within Bahia Laulau. Flooding could be from 28 -generated waves or flash floods where the rock and either storm or typhoon soils Javor surface runoff. In considering beach flooding by typhoon-generated swells, we can compare.sites by computing an Index of Specific Vulnerability, V S'(Doan and Siegrist, 1979). V is based upon empirically derived attenuation functions S (Komar, 1976) and studies done on Guam in connection with Typ*hoon Pamela (Ogg, 1977). A typhoon-generated wave with a height in meters. before -breaking, Ho, is attenuated. when traveling across a reef flat of width by.:the empirical function.: W/115 Ha Ho (0. 9) where :Ha is the attenuated height upon arriving at the beach. The Index of Specific Vulnerability is calculated as: V Ha - (1/D Ha) S max where D is the maximum effective depth of water, shore" ward of the reef max front. Oi.i*. Saipan VS ranges from 3.1 (Tanapag) to-7.6 ]Fahang) with 9. 0 being the @maximum vulnerability. Alluvial Processes: Drainage; overland soil and stream erosion and deposition; potential sedimentation problems. Rationale: Qualitative assessments of the position and condition of nearby str :eams and gulleys should accompany environmental evaluations. Soil is essentially a non-renewable resource in the tropics. Land stripped of vegetation will be quickly eroded down to bedrock on all but gentle slopes. Alluvium-choked ephemeral streams indicate soil and slope erosion upstream, episodic or possibly catastrophic stream discharge, flood potential and eventual sediment buildup downstream or on the reef flat. Subsurface: Porosity and permeability; infiltration rates. 29 Rationale: Very little surface water is retained on.the Tagpochau Limestone and virtually none on the Mariana and Tanapag formations in the Bahia p Laulau area. Infiltration rates are extreme. These formations are honeycombed with planar fractures, irregular fissures, caverns and caves. Surface instability arising from these subsurface features is demonstrated by swales and sink holes. Heavy construction planned for sites on these formations should be preceded by thorough subsurface investigation including geophysical surveying and borings. Coastline Configuration: Position and configxiration: of the. coastline as it relates to historic typhoon and normal seasonal wave energy directions. Rationale: All the coastal areas around Bahia Laulau are to some degree vulnerable to rapid erosional- depositional changes brought on by storm waves. Expectable sea and swell directions from local and regional weather patterns range from east to northeast except from June to August when low to moderate east-southeast seas can be expected (Doan and Siegrist, 1979). Historical , the typhoon- generated wave directions around Saipan range ly from the southeast to southwest. At each of the study sites, rates of sea cliff and headland retreat and/or backshore and beach redistribution and removal are dependent on wave direction and magnitude as well as coastline. configuration. Economic Resources: Estimate of the type of mineral resour@d'es in the vicinity of each site. Rationale: Bahia Laulau rocks have yielded limited quantities of highgrade manganese ores associated with the Tagpochau Limestone formation. It was pointed out by Cloud et. al. (1956), that although total 30 manganese at depth may be considerable, renewed mining would be dependent on external economic factors, especially world markets:. Bahia Laulau rock formations were also examined for possible use as construct' ate. Obviously, a well designed sampling a:nd testing .Ion aggreg program is mandated before claiming the certainty of any material being an economic resource. RESULTS Site 1, Sabanen Hagman Location: On terraced coastline east of Isleta Maigo (Unai Hagman) Profile: Figures 7a,b Local Rock Units: (13 units High Diversity) (Rock unit symbol's from Table 1) Bedrock Units: Mariana (dominant) Qmmt Qmr Tagpochau Tti, Ttd@, Ttr, Ttt, Tm Densinyama Tdcq Hagman (dominant) T h'c Mass, Wasting Units: Slump blocks Qx Debris blocks Q1 Unconsolidated Units: Beach Qrl Older Terrace Deposits Qp The structural geology and stratigraphy are very complex; all. the formations on the peninsula are cut by normal faults, some with large displacements. The Hagman formation also displays growth faults. Joints and joint sets are very pronounced in the Mariana but less so in the Tagpochau formations. Relatively steep dipping stratification planes contribute to reducing slope safety factors. 31 A A Ttd 100'- Tti Tdcq QX 50, Thc'; Qmij@ The SEA LEVEL- The HORIZONTAL SCALE 1cm 100m. VERTICAL SC ALE lcm 50M B B 150'r- 100. c Qmr@ 50, SEA LEVEL[- Qrnh CYI1 -50, Figures 7a and 7b:@ Vertical cross-sections at Sabanen Kagman.: Vicinity of Site 1. Section lines from Figure 6. Rock.unit symbols from Table 1. Circled numbers refer to text on Slope Stability. Th t Qx' @Thc ,q Th@, 32 A fracture compilation done by aerial photo interpretation (Figure 8) reveals that the peninsula including Site 1 is bounded on at least three sides by faults and is cut by several. prominent lineaments that could well be other faults or.:major joint traces. Local Soil Units: (7 units) Saipan Chacha Dandan Akina Dago Chinen Rough stony land on limestone (dominant) Rough broken land (dominant) Quarries Most sl Pp e.s are too steep to allow soil formation: Very shallow' stony to no soils on rough pinnacled Mariana formation. Slope Stability: (See Figures 7a,b) The' .'following types of mass wasting were observed in@. and around Site Rock Ialls: (ongoing): Labeled 1 on Figure 6, 7a,'b: Hagman and Mariana formations. Rock slides: (historic and ongoing): Labeled 2 on :Figure 6, 7a,b: Hagman and Mariana formations: Both rotational and translational types. Soil creep: (ongoing): Labeled 3 on Figure 6, 7a,b: Hagman, Tagpochau (Ttd) and Densinyama formations. Mass wasting on the south Hagman coastline is both active and unpre- dictable. Highly fractured bedrock, steeply-dipping soft and weathered volcanic strata, extremely steep slopes, high relief, sparse vegetation and 33 low-level shock waves from earthquakes and storm swells contribute to lessen safety factors to Site 1. Many of the slopes on Punitan Hagman are barely stable. Figure 8, shows the peninsula including Site 1. and depicts the distri- bution of historic and ongoing downhill movement of, materials. From air photos: rock falls, rock and debris slides and soil-creep can be plainly discerned. Directly offshore from Site 1, in Bahia Laulau'Y the submarine slope exceeds 180 within .5 km of the shore (locatibn 4 on Figures 7a,b). This slope is considerably higher than the 20 to 40 slopes at which underwater muds start to slump, flow or form turbidity currents., The thinly-bedded, tuffaceous Hagman formation probably crops out on' these slopes in a line between Dandan and Hagman. Periodically, and especially in a seismic region such as the Marianas, we should anticipate significant submarine movement of Hagman-derived muds along the slopes It also appears from the directions of dip of the Hagman as seen @near Site 1 that they coincide roughly. with the direction of submarine slope, thus further reducing any safety factor. Several writers (Tayama, 1938; Cloud, et. al., 1956) have suggested major submarine slumping as a possible mechanism for the formation and present configuration of Bahia Laulau. Danger from Flooding The probability of Site 1 being flooded by either storm waves or sur- f ace water is nil. Alluvial Processes There are no permanent streams in the Hagman area and only one or two important gully systems for storm drainage. Surface drainage across the 34 N, ing and Creeping SCAIE 1:5000: (4r@-!,Um; Volcanics AL S Loose Volcanic . I. r) 96c.ks.lidi-- C, N" N dip Fal .1-:V BAHIA LAuLAUJ Figure 8@ Mal@ of fracture traces and mass wasting at Site 1. See Figure6- indicate probable fault; dashed lines probable joints. :Solid lines LAnalysis from airphoto and ground verification.. L*Slum@,in@gand.,Cree@@ng@@ Volc @ ics @@ an 35 Mariana Limestone is short-lived because of its high. permeability. Slopes on the Hagman formation are highly vulnerable to sheetwash and soil removal. Sub surf ace From the nature of the outcrops it is obvious: that the Mariana and Tagpochau formations possess high porosity-permeabillt,y zones. Wells sunk in them, depending upon location, would only hit. :water at the contact between them and the underlying Hagman or at the freshwater- saltwater interface near sea level. Certainly, any construction planned for such heavily fractured and relatively soluble rock bLs the, Mariana or Tagpochau Limestone demands a complete subsurface evaluation. Coastline Configuration The Hagman site generally faces south with several prominent headlands developing southeast and southwest faces. However, normal VE tradewi.nds seriously affect erosion rates by refraction around Isleta Maigoi. Tropical storms and typhoons would probably attack the base of Site :1 directly promoting active coastline retreat and generating sufficient submarine instability to initiate submarine slides directly off the site. - Economic Resources The Japanese successfully developed a small manga -nese prospect on the east side of Hagman peninsula. The black oxide ore can sii.h be seen stockpiled on a bluff overlooking Unai Hagman. No estimate of: reserves is available. Such an estimate would require extensive geophysical: surveying and exploratory drilling. The stockpiled material was mined from the Tagpochau -formation, occurring as both a': vein filling and as the matrix in a brec,cia zone. Grinding, washing and jigging would probably concentrate the ore ef ficiently and inexpensively (using seawater). 36 The Mariana Limestone formation has been actively quarried on Hagman for fill material. The rock is crumbly and powdery and lacks: any good aggregate quality. Andesite gravels in the Hagman formation, however, certainly.:are well-suited for construction aggregate and appear at'@the top of the cliff s east of Site 1. Site 2, Onai Bapot Location: Beach and backshore 400 m (1,312 ft) northeast' of Trinchera Limestone and upslope terrain northwest of beach. Profile: Figure 9a,b Local Rock Units (Nine mapped units) (Rock unit symbols from Table Bedrock Units: Tanapag Qta Tagpochau Tti, Ttd Hagman Thc, Thb Unconsolidated Units: Beach Deposits Qrb Emerged Limesands Qrl Alluvium Qa' Older Terrace Deposits Qp The supraii.dal zone or backshore is dominated by Tanapag limestone and emerged sand and sandy gravel beach deposits. Northwest of the beach road the Tagpochau crops out along buttresses and benches between ephemeral stream valleys. Upslope the Tagpochau Limestone is underlain by highly weathered, tuffaceous Hagman volcanics and volcanoclastic sediments. Outcrops of the calcareous sandstone and shaly Donni member (Ttd) of the Tagpochau Limestone can be viewed on the hilly road leading almost due north from the beach road (following the former Japanese railroad line). 37 A A 100: q) T@d SE LL EL A' V Pta: Q _77 -501- Orb! HORIZONAL SCALE 1CM = 100M VERTICAL SCALE 1c m = 50m @'B 100, 5 0'_ 'QP Thb SEA LEVEL;. Qa@ Qrj@ Qrb' Figures 9a ahd 9b.Vertical cross-sections at Unai Bapot. Vicinity of Site 2. Section lines from Figure 6 - Rock unit symbols from Table 1. Circled numbers refer to text.,.,on Slope Stability. 38 Normal stratigraphic relationships are evidence for little or no faulting. Jointing in the limestone member of the Tagp'ochau (Tti) is prominent but with no apparent pattern. Beach deposits and emerged limesands are both calcareous- and non- calcareous (silicate, oxide). Iron oxide (magnetite) and iron-@titanium oxide (ilmenite) is found along intertidal foreshore,' beach, emerged beach and in ephemeral stream deposits (Qa). Soil Units: (5 units) Saipan Chacha Lito Akino Dago Chinen Shioya Rough stony land on limestone Rough broken 'land 9 Good correlation exists between soil and rock units, Sai' pan Chacha on Tagpocha*.U;, rough stonyland on Tanapag; rough broken- land on Hagman; Shioya soils. on calcareous sands and gravels. Slope Stability: (Figures 9a,b) Lower slopes are generally stable with minor soil creep on Tagpochau Limestone buttresses along the road. Slopes on Hagman and Donni member of Tagpochau Limestone display slumping and major soil creep (location 3, Figures 9a,b). Several mudflows are interlayered with alluvial valley fills (location 1, Figures 9a,b). A rock slide talus deposit (location 2, Figures 9a,b), occurs at the base of a steep Tagpochau Limestone cliff. The index of Specific Vulnerability, VSP ranges from 7..3 to 7.7, second highest on Saipan and third highest among all beaches on Rota, Tinian and Saipan. Moreover Unai Bapot's location on the north side of Bahia Laulau 39 means that Hop the initial height of typhoon- generated waves, might grow to be well in excess of the standard nine-meter typhoon wave (Bascom., 1964). Alluvial Processes Ephemeral streams draining the slopes north a.nd northwest of Site 2 have deposited substantial alluvial fans composed :of gravels, cobbles and sand intercalated with clay-rich layers and occasion al. debris flows. These deposits are designated Qa on Figures 9a,b. The large quantity of these materials attests to the velocity and discharge of flash floods as well as to upper slope instability, soil erosion and gullying. Eventually, this pre- dominantly silicate-oxide detritus reaches the beach and reef. flat area where it first forms small deltas; later the sandy portion is, redistributed parallel to the beach by longshore currents while the clays are carried downward. Subsurface The Tanapag and Tagpochau Limestone formations are doubtless cavernous. Although no sinkholes were observed, a large cave.in the Tagpochau limestone formation has its entrance on the beach road 400 M. (1,312 ft) west of Site 2. Fresh water probably runs off the upslope Hagman'. limestone formation, down to the cavernous': Tagpochau limestone formation and back to either the impermeable Hagman @or to the'water table which is in hydrostatic balance with sea level. Coastline Configuration Unai Bapot is positioned in Laulau such that is receives minimum expectable Northeast tradewind swell and maximum expectable typh!D'on swell. Economic Resources The Tagpochau ::formation cropping put immediately north of @the beach road appears to possess the requisite density required for construction 40 aggregate. It certainly appears no different in hand specimens from Tagpochau Limestone material presently being mined for aggregate near Marpi. Site 3, Unai Laulau Location: Northwest extreme on Bahia Laulau, 1. 7 km 1.'1 mile W) west-southwest of Unai Bapot, 150 m (492 ft) 'along coast nortih@east of point where beach road turns west toward Cross-Island highway- Profile: Figured 10a,b Rock Units: (7 mapped units) (Rock unit symbols from Table 1)': Bedrock Units: Tanapag Qta Mariana (dominant) Qma,. Qmm Tagpochau Qti, Qtd. Unconsolidated Units: Beach deposits Qrb Alluvium Qa There are no volcanic rocks at Site 3. The stratigraphic. sequence features Tanapag :Teefal limestone veneering seaward benches of Mariana and Tagpo- chau formation. Tagpochau Donni sandstone member (Ttd)' is in fault con- tact with T@,Lgpochau limestone on slope of major north-south vine (north of Chamorro Village). Soil Units: (4 units) Saipan - Chacha Chinen Shioya Rough Stony Land on Limestones Shallow yellow-red to reddish yellow brown clay loams on Mariana and Tagpo- chau Limestone formation. 41 A A' 1001-, (D(D Tti" Qma! Ttd QMM, JEA LEVEL Tt.d' -501- QMM HORIZONTAL.SCALE JCM 1OOM VERTICAL SCALE@: @lcm 50M .B' B 1001: 50'_ Tti - Ttd Qma, SEA LEVEL QTM . lQta- -50 Figures 10a & 10b. Vertical cross-sections at Unai Laulau.. Vicinity of Site 3. Section lines from Figure 6. Rock unit symbols from Table 1. Tt 42. Slope Stability: (Figures 10a,b) Relative stability of slopes characterizes this site. Minor. slumping q occurs in the Tagpochau (Ttd) Donni sandstone member (location 1, Figures 10a,b). Possible rotational sliding of Tagpochau limestone is indicated at fault in ravine. Soil creep is evidenced on road and hillsides below Chamorro Village. Danger from Flooding Danger of flooding is less severe than at Site 2. V S ranges from 5.1 to 5. 5. Downslope runoff and stream discha@rges are not likely to cause dangerous flooding. The small watershed (collecting area) and lack of impermeable volcanics needed to prevent infiltation and loss of discharge lower the possibility of serious flooding. Site 3 is somewhat more protected than Site '2 -from flooding due to expectable typhoon-generated swells; it is. generally more susceptible to tradewin d- driven wave flooding. Alluvial Processes Some active soil erosion and alluvial transport were noted in gullys along the road. Alluvial fill occupies a major ravine north -of Chamorro Village. The road itself may become a sediment channel during typhoon conditions. Subsurface Highly fractured bedrock. Construction on Mariana and -Tagpochau limestone.units inadvisable without thorough subsurface investigation. Coastline Configuration Vulnerable to both typhoon and tradewind propagated waves. Active headland erosion on cliffs below Chamorro Village; very susceptible to major storms. Longshore drift is generally northeast to southwest. 43 Economic Resources Rubbly, sugary coralline Mariana limestone was formerly quarried from the hillside immediately north of road, 400 m:,(1,312 ft) west of Bay. No potential. for aggregate-quality materials. Site 4, Unai Dandan Location: Immediately southeast of Unai Dan'dan along 10 m,.'(33 ft) high wave-cut bench, approximately 500 m (1,64:0 ft) from n0rth6ast end of airport runway. Profile: Figure 11 Rock Units: (4 units:low diversity) (Rock unit symbols from. Table 1).* Bedrock Units: Tanapag Qta Mariana (dominant) @Qmm, U.C: n onsolidated Units: Beach Deposits Qrb Ten and thirty-meter wave-abrasion terraces cut into massiVe and cavernous Mariana forereef detrital limestone. Numerous solution pipe's and joints are found in', !Mariana and in subordinate Tanapag limestone.: :No faulting evi- dent. Secondary solution features are pervasive in quar,ry outcrops of Mariana limestone. Soil Units: (1 unit) Rough stony land on limestone. Soil found only in irregular pockets in solution pip es and joints in limestone. Slope Stability: (Figure 11) Slopes at Site 4 are stable. Only occasional rock falls from open- tension fractures above wave-cut notches present any slope problems (Location 1, on Figure 11). 44 A A IOU 50- QMM .SEA LEVEL Qtd -50.- cr HORIZONTAL SCALE 1CM 100M VERTICAL SCALE 1cm 50m: Figure 11. Vertical cross-section at Unai Dandan. Vicinity of Site 4. Section line from Figure 6 Rock unit symbols from Table 1. Circled numbers refer to text on Slope Stability. 45 Danger from Flooding None. Rapid infiltration of surface water' prevents sheetwash or chan- nel flow. Typhoon waves from unexpectable NE direction could. easily spray upper 30,m bench. Alluvial Processes No surface water. Any mobilized soil moves into: fractures' :and solution pipes, not along surface. Sub surf ace m ur Very porous with high implied permeability. Rando. s face depres- sions and perhaps sink hol.es to be expected.: Thorough, subsurface analysis must precede heavy construction. Coastline. Configurations N oi.rtheas t facing coastline along Bahia Laulau should,: anticipate almost constant wave attack. Headlands will be especially vulnerable at Site 4. Economic Resources The. Mariana limestone has been quarried at this site,@ practically since the reconquest of Saipan. It appears on 1946 airphot6s.- The material in outcrop is'. deceptively hard and appears to be appropriate for aggregate. But, like most near-surface Mariana limestone, the rocks,.have been altered by solution and reprecipitation giving it a marbleized. patina. Subsurface samples ten d to be more crumbly and chalky except along solution pipes and fractures where 'the limestone resembles outcrop samples. DISCUSSION Comparison of Sites Table 4 (Appendix A) presents a synopsis of the' major features presented in the site evaluations, enabling qualitative co Impansons to be drawn. For major on-shore construction, Site 4 is generally the most 46 suitable in that it exhibits the fewest unfavorable geologic constraints. However, all the sites have an abundance of limestone bedrock that is notorious for subsurface permeability and porosity. Very careful field mapping, geophysical profiling, airphoto, interpreting and drilling should precede heavy construction. The presence of fractures and caverns may be such as to preclude any of the sites being acceptable Geologically, Site 1 offers to tourists and naturalists alike one of the most uniquely interesting and important landscapes *in the entire Northern Marianas. Hagman constitutes an outdoor laboratory illustrating the major steps in the 30-million year physical evolution of Saipan from a submarine volcano to a terraced "high" island. CONCLUSIONS Site 1 is a very diverse area and scenic location. It has gTeat diversity of geology, extreme instability. of onshore slopes, probable instability offshore, w ave-vulner ability to cliffs and headlands, no surface water, fractured and permeable bedrock and a small manganese prospect. Site 2 is generally a peaceful recreational site. However, it is highly vulnerable to typhoon swells as well as to flash flooding down ravines to the north. Although there is a strong possibility of flooding i the lower elevation slopes are stable. Site 3 is generally a recreational location like Site 2 wit*@ relatively stable slopes and coastline. There is the potential danger of flooding during typhoons. like Site 2. Alluvial processes in the area pr.esent few sedimentation or drainage problems. However, subsurface porosity may present construction problems. Site 4 is a scenic location with excellent view of Bahia La'ulau and Hagman. Here there are stable slopes and the coastline is generally 47 protected from typhoon-driven waves. However, prevailing winds and waves create rough offshore conditions as a normal @'occurence. The substrate is very porous and there are no streams. 48 LITERATURE CITED Cloud, P.E., Jr., Schmidt, R.G., and Burke, H. W. 1956. Geology of Saipan, Mariana Islands, Part 1, General geology. U. S. Geological Survey Professional Paper. 280-A, 126p. Doan, D.B., and Siegrist, H.G., Jr. 1979. Beaches'.. coastal environments, and alternative sources of fine aggretage in. the Northern Mariana Islands. Coastal Resources Management, Executive Office of the Gover- nor, Commonwealth of the Northern Mariana Islands. 108p. Komar, P. D. 1976. Beach Processes and Sedimentation. Prentice-Hall, Englewood Cliffs, New Jersey. 429p. McCracken, R. J. 1957. Geology of Saipan, Mariana Islands, Part 2, Pchology and soils. Chapt. D. Soils, U. : S. Geological Survey, Professional Paper. 280-D 17p. Ogg, J. G. 1977. The impact of Typhoon Pamela (1976) on. the Beaches of Guam. (Abst.). EOS, Vol. 58, No. 12. Dec. 1977. Tayama, R. 1938. Geomorphology, geology, and coral reefs of Saipan Island. Trop. Industry Inst. Bull. 1:1-62. [In Japanese-translation) . 49 PHYSICAL PARAMETERS INTRODUCTION This section includes data on physical parameters found -specifically within Bahia Laulau or in the general Saipan area. General 'climatological data include: air temperature, relative humidity, rainfall, wind '@@dire ction and speed, sea temperature, occurence of tropical disturbances. ;@nd typhoons. Specific data collected within Bahia Laulau include deep water temperature and salinity, wind direction and speed@, bathymetric profile, inshoreand offshore current patterns and nearshore water quality. METHODS General climatological data mentioned above wer e comp iled from existing data (U. S. Naval Weather Service Command, 1971; Naval Oceanography Command Center, Guam, 1983; U.S. Department of Co'inmerce, National Climate Center, 1981). Wind direction and speed were Measured during each of the four, field investigations. Oceanic temperature and salinity were measured on :November 4, 1982 at the surface@ and four depths (229 m (750 ft) 305 m (1,000 381 m (1,250 ft), 457 m, (1,500 ft)) directly offshore of the proposed 'OTEC site (Figure 12) (Table 5, Appendix A). All sampling was carried out from the M/V Bahia Laulau and the CRMO Zodiac utilizing a 1.2 liter Nanson-type water sampler (G. M. Manufacturing Co.) equipped with Kahlisco deep sea reversing thermometers (-20 to 350C) . By using the combination of protected and unprotected reversing thermometer readings, accurate temperature measurements were determined and the depths calculated. A single bathymetric profile was taken off the proposed Bahia Laulau OTEC site. This profile was made to a depth of 732 m (2,400 ft) with a Surface 0 2 (229,22.5') Al, C) x 3 - (305,12.3'- CL4 (381@9-30) 4 - (457,7.40) 5 (525,6.4)_W (550,4.4 0) 6 8 10 12 22 24 Temperature OC Figure 12.. Temperc@ture profile from surface to depth of 4S7 m off pro-posed OTEC site.. 51 Fine Line Fathometer (Ross Model 400-A). The transect followed a compass course of. 1650(SSE) until the limit of the recording fathom eter .'as reached (Figure 13). To determine general water movement patt erns of the Bay, 'a necessity for a potential OTEC operation or other future activity that ffiay'be planned for the.area, it was determined that a year-16ng study was..n'eceissary using drift drogues placed at various points within Bahia Laulau. Is, Water movement and current patterns were investigated: quarterly j.: over a rogues off :a year period employing 1 m and 5 m drift d shore nd fluorescene dye releases on the reef-flats. Drogues were checked .:every 30' to 60 minutes after release and their position determined by triangulation (fix) on preestablished marks with a hand-bearing compass. Depending upon the er picked u '.'and: restarted or distance traveled, the drogue was then eith p allowed. to. drift another 30 to 60 minutes. Tracks wer e'then plotted on a chart to. determine general water movement patterns. Additionally, at the time of eve ry set or fix the direction and velocity of the,wihd:was noted. On the reef flats, dye was released and allowed to:@tra ."V',el: a distance of 10 m (33 ft). The time and direction of travel were recorde d,'and from this direction and 'Velocity (meters/second) of the current were,. determined. Each dye release was repeated three times and averaged for eac.h. location. Dye release studies were done only for sites 2 and 3 where r eef flats occur. Nearshore water quality has only been superficially evaluated in the Bahia Laulau area. The CNMI Department of Environmental Quality collected water samples from 10 stations in Bahia Laulau during February 1983 (Figure 13). These 10 samples were evaluated for 'total and fecal coliform only indicating the degree of pollution in localized areas. Future 46, K f1l; f -5 All f C 4L ,\V- A _J f ...... . .... . ? IleI r la 'T F(@AI(11@ A t@ @11 41 33 29 r '28 24'. 4) )o 2, ".1 4) loo 61 14 it hj:1 48 @17 Ile Ile' 61 40 6 C@ a? so N ;o '21 21 04" lee, , " 45 14 150 in '41 t. 1; 95 141 Ise Ile 60 29 ) - --- ..I$ 14160 leo 4 qj '-, 17) ;'-o 9, 6, 50 45 )5 )5 56 IR4I - - loo.. A 26 46 '69 19s 91 68 92 145 ?s oo.. .to .It, i!21 3.q Igo Its 'so ""oo ..... 1 67 89 1 be .57 145 26 to go Vo Ise 145 23 a? gs .1 152 7oo Ise so 35 $4 2oo No 'o"ll i 95" Ile 190 14 191 2oo .1a so 11 as,' 21o 2oo 1 756 155 12 49 13 91 too Ise 290 28o 26 to do vA, vA". I Ile 21o o. .9; a loo 165 2(lo 1,71 ta 41 56 to 16 ??a 23s loo Ile )"o Igo 149 247 Igo 3. 08 '91 195 )oo is 57 ?no 74o Igo loo )o l2o 1 137 to 165 24S LEGEND AN go',' Iss '18 Vo 57 go Be 72o Ile '4o E PROPOSED OTEC SITE 96 Ile 4 145 STUDY SITES .9, 19 75 "loo, .7; 31 96 BOTTOM PROFILE AND TEMP. P 25 so 5 F 91 '7S is 33 64 too A WATER QUALITY MONITORING S 3, LIMITS OF STUDY SITE so Lim its of s tudy sites 1-4, prop J Figure 13. bathymetric profile and water q jl@ ly stations. 53 monitoring will include five additional parameters; turbidity., suspended solids, chlorides (salinity), dissolved oxygen and pH. RESULTS Air Temperature The island of Saipan is located between: 1.5005' and 150.201: North latitude and 145.0401 and 1450501 East longitude. The climate of Saipan'.Is considered tropical,. being almost uniformly warm and humid throughout the year. Afternoon temperatures are typically in the' middle .':or high,',: eighties and nighttime temperatures typicallty fall to the 'middle or low, se*iienties'. The average annual temperature on Saipan is 27.50 C (81.50F),'. with mean maximum: temperature of 32.20 C (900F) and a mean, minimum, temperature of 22.20 C (720F) (U.S. Naval Weather Service, 1971). The daily temperature fluctuation is' about 100F. The hottest months are. :usually June through October, while the cooler season falls between the months@ -of January and April. Relative Humidity Relative humidity generally varies from 75 to 100 peften't with an annual mean value'! of 81 percent (U.S. Naval Weather Service, 1 1971). Humidity commonly ranges from around 65-75 percent in the early afternoon or during the winter months to 85-95 percent at night or during the hotter, rainy months (Naval Oceanography Command Center, G uam 1983). Both temperature and humidity vary only slightly throughout the year, but rainfall and wind conditions vary markedly and it is these variations that define the seasons on Saipan. Rainf all Annual rainfall on Saipan averages approximately 86 inches with a monthly average of 7.2 inches. The wettest months are August and 54 September with averages of about 13-14 inches while the dryest months are February and March which average 2.5 - 3.5 inches of precipitation (Hinz, 1980 and U.S. Dept. of Commerce, National Climate Center, 1981). Data from the U.S. Coast Guard Station in the southeastern'. portion of the island indicate an average annual precipitation of 76.6 inches (recent 10 year period) ranging from a low of 58.85 inches to a high of 102.23 inches. Wind In the vicinity of Saipan, the steadiest winds -occur when the winter monsoon and the northeast trades reinforce each other. Between November and April, northeasterly to easterly winds prevail approximately 70 percent of the time at a velocity of 10-12 knots (kn) (8.7 10 mph) (Hinz, 1980). Easterly winds predominate 47.7 percent annually with a mean speed of 12.0' kn (10 mph),while northeasterly winds occur 24.9 percent of the year with a mean speed of 12.5 kn (11 mph) (U.S. 'Naval Weather Service Command, 1971). The calmest months of the year are July September when winds typically., average less than 6 kn (5 mph). Water Surface Temperature The mean surface sea temperature for Saipan is 29.60 C (83.40F). The mean minimum temperature of 27.30 C (81.10F) occurs during February, while August has the highest mean temperature of 29.60 C (85.120F) (U.S. Naval Weather Service Command, 1971). Tropical Disturbances and Typhoons Saipan is in an area where many tropical disturbances occur'. Tropical storms become typhoons if surface winds at some time during the progress of the storm reach a speed of 64 kn (55 mph) or greater. Although the storm 55 tracks are often erratic when in the vicinity of Saipan, they generally move towards the WNW. Tropical disturbances occur most often between July and November and are least. likely to occur from January to April. One sour ce', shows an average of one. storm a year originating in or. passing over, thi,s' 'area (Hinz, 1980). Guam data (1959 - 1981) shows the occurance of all tropical cyclones (depressions, storms and typhoons) was greatest during the; months of August (6.3 cyclones) and September (5.9) and the,'least', fr6 quent :during February (0.3@, January (0.6) and March (0 7) (U. S. Naval'Qceanography Command Center, 1983). The frequency of typhoons follows the exact same monthly pattern, ranging from a low of 0.04 typhoons in te@bruary towa high of 3.4:in August. Oceanic Temperature and Salinity Profiles Temj?eratures at the proposed OTEC site appear @to follow a well defined profile t 'ical in the Western Pacific, i.e., a warm, well mix e a surface layer yp of nearly. constant temperature, a thermocline region ,%@h'ere temperature declines with increasing depth and a deep cold layer@ @(Figure 12). The depth at 'which these regions or zones occur vary on- a 'global scale with latitude and season. At lower latitudes (00-150 north or south) the thermocline depth begins much shallower than that found'@.at mid-latitudes: usually related to frequency of storm activity. Typically, the lack of storm activity and lower air temperatures in spring result in a shallow, highly angular thermocline. Increased air temperatures and more' frequent storms in late summer and fall tend to create a deeper mixed layer thus increasing the thermocline depth and smoothing the shape of the profile. Water temperature was measured at the surface and four depths as follows (229, 305, 381 and 457 m) (Figure 13). Temperature decreased from 56 28.40 C (83.10 F) at the surface to 22.50 C (72.50 F) at 229 m (Table 5, Appendix A). Between 22.9 m and 457 m the temperature decreased to 7.40C (45.3' F). Although we did not actually measure the temperature between 457 and 550 m we did extrapolate the tempera tures based on similar observations in the region. The temperatures at :.,525 and 550 m were extrapolated to be 6.40 C (43.50 F) and 4.40 C (39.9") F) respectively. Salinity is the most frequently measured chemical parameter in seawater. It is the single measurable parameter which can be used in conjunction with temperature and pressure to calculate other 'properties of seawater, e.g. density. A change of 1 percent in salinity has a much I arger effect on However, the wider range in density than a 11C change in temperature. temperature variation dominates the density profile. The salinity profile off the proposed OTEC site is similar in shapp to that shown in Lassuy (1979) and corresponds well with Williams (1962) and Gregg J1973) for the Mid-Pacific region. Craig, et. al. (1977) reported average isurface salinities of 34.5 percent and a maximum of 34.9-35.1 percent. between 150 and 200 m (492-656 ft) for ocean -water near Guam. These coincide with observed values at similar depths of the Bahia Laulau OTEC site (Table 5, Appendix A). There appears to be a salinify inversion between the surface and 300 m (1,000 ft). This inversion is typical and has been reported in nearshore waters surrounding Guam and other. islands of the Marianas archipelago (Lassuy, 1979). Bottom Profile Figure 13 identifies the site where bathymetric. studies took place. Figure 14 illustrates the profile and degree of slope. It is evident. from this profile that the slope is extreme (3E = 45%) from the surface to a' depth of approximately 550 m (1,800 ft) only 1.1 km (0.7 miles) offshore. From this Surface 0 Slope 55% 2 3 Slope 46% 4 x P 5 Slope 33% P4 CZ) 6 Slopp,,.= j5% 7 2 4 6 8 10 12 14 16 18 20 Disfance from shore (m x 100) Figure 14. Bottom profile from shoreline to a depth, of - 730 -m . (2400. ft) o proposed OTEC site. Average slope = 37 percent. 58 depth, the slope smooths out gradually to 15 percent' at a'depth of approxi- mately 700 m (2,400 ft) 1.8 km (1.1 miles) offshore along the profile. Although bathymetric studies were not conducted in other areas of Bahia Laulau, examination of hydrographic charts. -indicates that the 100 fathom contour (600 ft) runs closest to shore (0.5 km, 1,584 ft) along the Hagman peninsula. This contour runs nearly as close- to the shore along the northwestern coast of Naftan Point, the southern extreme of Bahia Laulau. The 100 and 20 fathom contour lines are fairly uniform in terms of distance from shore. With the exception of Hagman atd Naftan Points, bathymetric profiles within central Bahia Laulau are more gradual with less degree of slope, and shallower further offshore. Once offshore, depth increases drastically in the direction of the Marianas Trench. Having adequate depths so close to shore at Hagman Point suggests a significant resource in term.s of OTEC development and energy production. Current Patterns The. currents in Bahia Laulau are not well kn own. Historically, no previous work has been done anywhere in the Bay regarding water movement. Fishermen who fish along the cliffs or 100-fathom contour from station la to the northeastern tip of Bahia Laulau (Puntan Hagman) frequently report the current running along the contour to* the east, opposite in direction to prevailing wind and surface waves. Iti has been postulated that an overall circular current pattern may exist in Bahia Laulau. with large.volumes of water entering the southern portion of the Bay then traveling along the inside contours until it exits at the northeastern opening (Figure 15)@' The following are results from current studies in Bahia Laulau. 5s- 45' 30' 46' ? If r rvl c If- -vv PROPOSED r r ) If q @7v 3o 40t AWA' it j 4r'@ , 'i" , 4 It )o;, 2-c. oo 114% 52 7i, tj 1, to "it 36 74 too., V\ 9s 17 o to \\N 24 -114@1 so if of 3 9) 11`3 45 6," 95 26 46 11" Ifil I to to J9 1" 4) 89 19 ....9 76 4 Flu o '9o 9!", 152 zoo Igo ]so 2',0 54 ?DO, 2'o f9j IF 29 34 so 230 756 zoo .43 a zoo 29o 268 zoo 14 is 71 9 Pa Iss 28o 49 do It 36 145 27o 718 zoo 2, ]DO llo to 22o j.'o 3 28 1po .9 49o 'i. 14 149 74? 19o too ]to s: '78 '97 19s 6,04 "o 341 Is" 57 8 )o to 4% to$ zoo too 29o )to )do 'to 'so 22o joo ma'' 22o ??1 )64 oc.. IM too Illin 4ff9 It III Its I'o los 9, so !q 20 too so 57 zoo 2cs )so 41a 14 a Is 26 Its Iss of . IF Figure 15'.' Theoretical' @6del of 1?11 Al m ;o ;o patterns in Bahia La 61 156 60 Results Off shore A. November 1982, February 1983, May 1983 and September 1983 The..results of the offshore current studies conducted November 5 69 1982, February 9, May 10 - 11 and September 29730, N83 are shown in Figures :16 a,b,c,d. Extremely strong winds and heavy seas restricted drogue placement in the vicinity of Sites 1, la', and 2 @during November, but drogue releases were completed at all sites in.February, May, and September 1983. In addition, a mid-bay release was conducted durin the.May survey. 9 Although current patterns were not clearly establishe'd,'by this survey some general trends have been noted. It seems likely that the majority of the water, enters Bahia Laulau from the northeast (prevailing wind direction) and splits apart at Dandan Point at the southern part of. the bay. This would form a rather consistent and strong clockwise water p'attern within the center of Bahia Laulau. The leading edge of this waterlmas's likely moves along or hear the 100 fathom - (600 ft) contour eventually -,emerging in the northern part of the bay at Puntan Hagman. Here it '@would' enter deeper water and/or merge with the overall water mass moving to the southwest (Figure 15). Near-shore water circulation patterns of Bahia Laulati inside the 100 fathom (60.0 ft) contour are much more complex and seas onally variable. They are influenced more by the prevailing winds and seas and preliminary data suggest they may run counter to the deeper water circulation by following the shoreline. Several small eddies may also form in more enclosed areas such as the cove-like embayments found at Sites 2 and,'3. Most of the drogues that were released close to shore traveled along the shore or 4 b 30' 46' 4 P IT 7 9 j1W11 I-- V:1, 1666 fig", A M r it r Oil# & 0. -\J 41" !6qf.,.4 4,y '9 @2, x 2- .-- I \ @ % 4 \'N M 26 23 W 2. A30 1@ 429@_ o 14 11-- 17'. 2132 4 9A49, A 28 3 t WOO 14 17 35 13, .29, 54 A 41', 24 43 go 21) 021 4) 55 56 7.1 94 3 Orl 117 42 52 45 if 12 19 hi, 18 67 6 43 140 35 q. 14 53 r- 63 634 b 87 50 .30 30"1--, ;0 21 57 ! -95 0 2. jr) 51 74 84 150 1 44 38 54, 66 of 11 95 26 3 31 047 58 110 6 --15 74 -801 57 POO 31 14 7 931 I'll . 45 IRAI 173 1101- ()u 46 56 195 91 70 48 A P-1 ol 05 75 Ono f 40 67 8,41(j 210 14', to. 95"1 52 j 35 54' 200 210 190 2, 95, 195 34 '1 51 43 051 23.0 4 155 200 NOV 82 73 Q 49 93 210. 258 ,76 1 3 26 1145 DRIFT DEPTH DISTANCE Sp 749 ht, 238 10, 160 METERS (N.M) M/sec 165 70 1,10 41 235 14 9 06 1 1M 2060 (1.11) 0.38 J. bt, 191 195 .2, 5m 1975 (1.07) 0.37 .,;o 200 4 110 1ON 19U 200 3 1M 575 (0.31) 0.16 '120 "37 4-1i 4. 5m 360 (0.19) 0.10 Ibb Z4 5 I I fit 178 210 1 go too 220 5 IM 1000 (0.54) 0.28 140 80 6 5M 870 (0.47) 0.24 91 220 7 1 rn 1500 (0.81) 0.42 :U 4 U I,20 Ito IJO 8 5m 1040 (0.56) 0.29 I (if, 145 j 90 30 too 390 9 im 180 (0.10) 0.05 10 5m 220 (0.12) 0.06 Figure 1'6a..-.Map o,f Bahia Laulau showing 1 m and S mdrift.dTogup-tr4cks an, plankton sampling stations. Date: 'November S-6) 1982. 4 V \`\IJ it it r It 1716 ,,j A A IN. IN ir- INS 7 4 N @jf 6, 6i NN 252 2. IFI 26 4 ... 23 1 30 -Nj L p 14 ]1 1.- 13 It, 21 P 13 45 1q. 12 1 *A.@ I RIN. A 14, 235 91 P-8 114 1,6 33 .29, 55 41'4@06 .:, 41 , 112 56 94 OU 96 45 31: 55 "C I 0( 252 119) 19 27\ 12 IV fil 61 14 43 53 63 157 71 ""6 63 4o 87 50 30 6 9 A 0 1 95 51 84 66 7 N q 35 JI, 74 52.,"' [so NN P -10 14? 110 60 38 13 8 It 3 E. 23 31 74 91, 26 158 29 34 51 1 6o 180 P 91 61 51) 35 - 19 .4 93 45 3 AP-9 IF.4 173 100 5 195 91 P - 6 A 41@ 6 [to. 70 :4@ I C. 75 Too 40 210 1 145 87 95" 2 LQ so 201) "'0 95 1113 05 51 1 1 , 2: 43 85' I FEB 83 14 73 155 200 12 C? 93" 210 1 1145 DRIFT DEPTH DISTANCE SPEE 1249 111! IjI 4A 160 219 METERS. (N,M) . Mlsec (K ?DO 14 700 1 1171 250 (0.13) 0.07 (0. 41 'Z 5 rd 370 (0.120) 0. 10 (0. 7 J. 3 -1m 475-:(0.23) 0.12 (0. 14 P71 1,12 @00 .5m 3,50 (0.19) 0.10 (0. 5 Im 5 0 '(G.* 1'9 009-'. Q., 1 12uu fit 'jo 155 178 2 10 6 5 M 400 (0.22) 0.10 (0. V 140 Ieu 120 7 1 M 500 (0.27) 0.14 (0. 42 78 8 5m 560.0.30) 0.16 (0. 4U 1@0 130 o60 145 'JU 1or-, I- 49 Figure 16b. of Bahia Laulau Showing 1 m and 5 m. drift drogue tracks ar plankton sampling stations. Dnte: Februnry 9, 1,983. M ss 4b' 15' 30* 4!, 41, J, lp I- y rr - -RNA i .11 7! I f 012 -P V .V" A 2, lid NJ- 2 '22'. F,; 6, i2 24 15 q 14 2'. 252 0 13 20 -23 Z,3 2F) 1,718 31) 29 13 P,415,"1'6 27 23 r 14 t. 33 28j 1r 28 .29 43 54 66 4 3 554 I 20 it, 91 13 17, q 42 27\ A A,j 23 100 "1 12 56 7J 94 .100 " 96 45 3 5971 14 It--' ' b 45 t4 18 30 31 .0 61 35 /6 61 1 6, 43 140 13 63 63 41 ;0 2; 57 87 .50 00 13 95 16 11 a 9 40 2, 6 1 84 52 66 45 74 160 38 13 47 60 110 29 -t5 160 180 158 34 19 IN0 3 10 3@` -13 :,I MAY 83 40 AP 100 2 DRIFT DEPTH DISTANCE SPEED DIRECTION WIND 2 METERS (N.N0 M/sec (Knots) DIR. SPEED (Kts) 10 28) 1950 0900 14- 190 Z, J. 1. Im 700 (0.38) 0.14 (0. 18 2 5m 400 (0.22) 0.08 (0.16) 2350 same 200 3 1m 300 (0.16) 0.08 (0.16) 3550 0900 14-18 12 4 5m 300 -(0.16) 0.08 (0,16) .3550 same 80 .2fln 76 'if, 124Y ffJ'. 19: 5 Im. 300 @(O "16) 0.08 (0, 16Y 2300 0650 10-14 6 5m 380 (0.21) 0.11 (0121) 2100 same J10 9 7 1m 540 (0.29) 0.15 (0.29) 1410 0650 10-14 - 5m 670 (0.47) 0.24 (0.47) 1300 same 9 1 M 640 (0.35) 0.15 (0.31) 2750 0850 B-10 .10 Sm' 640 (0;35) .0.15 (0.31) 2750 same Figure 16c. @Up of Bahia Laulau showing 1 mand 5 mdrift drogue tracks and velocity and plankton sampling stations. Date: Play 10-11, 1983. 00 A P - 19,2 jo 130 180 )90 .1U 47 ill 0. 310 Ys 35 50 5, 91 2M X 26 b4 ji 2U!, 71 2b 3) 100 b6 J J4 kb 91 175 J1 4 5 JIT I I .-, I "@2 Oi !50 ft) it 7@ 0, A. .77 % 0 23 2, f 3 2 12 1@ 4 - 24 5 23 2 r\ z(20 28 26 30 30 1,A 3., 30 IM, 13 to.,% 14 11 "12 It 14 27 to 3 45 i2 "'A 14 IS 14 _Ox 28 2 17 -28 35 43 P-2 ?,,2 4A3j floe. .29/ b4 43 20 241' 43 91 55 41@ 8,, C 55 $#I n 1 /3 - 17.312 56 9 4 W 31 _': f@_'V 01 1 .1 6 45 .0 2 5V-25,26 42 19 27 L (@7@ U43 61 140 71 61 53 13 35 kl I , , , ,10 63 40 57 130, !0,1 2Y 875 2,: 51 .4 4@ V'N' _j 150 66 33 95 60 4 2,4 180 158 110 29 5 11 a 0 14 51 6 916 4Ap 19 93 1) I- 173 110- 5 45 35' 46 1114 195 1 2 49 16-0 00, 70 j '!'o 0 1 100 401 210 145 87 95 200 1.'0' 35 152 00 54 200 @J 7;1 25 14 951 195 51 SEPT 83 .4 4) 85" 14 17 731 200 DRIFT DEPTH DISTANCE SPEED 499 210 1 76 13 IG 11 26 METERS (N.M) M/sec (Kn )G 145 10, 19, 49 too If 165 f @o 1M 360 (0.19) 25m.. A50 0.10 (0.1 (0. 2 4) 0.13 (0.2 A'? ,tj 'Irn .1075-(0.58) 0.30 (0.5 ,. .I -3. 7 45riI -0.26 (0.5 950 (0.51), 7q, ..8\ 2 7j -'o if 5- 1M -456. 10.13 -(0.2 I W!, 65m 380 (0.21) 170 no IOU 140 22 71M 340 (0.18) 0.09 (0.1 85m 420 (0.23) 0.12 (0.2 Figure 16d. Map of Bahia Laulau showing I m, and 5-m drift drogue tracks an Plankton sampling stations. Date: September 29-30, 1983. 65 towards shore in a general south to southwest direction. A generalized model of currents in Bahia Laulau is shown in Figure 15. Inshore The inshore (reef-flat) current patterns are typical of any reef flat that is influenced by winds and tidal changes. Since depth of water covering the reef-flat areas varies from almost zero at very low tides to as much as one meter o .r more at high tide, the prevailing winds usually dictate the direction and velocity of the water movement. The majority of the dye releases at Sites 2 and 3 resulted in movement 'parallel to the shoreline, with the general water movement to the west at Site 2 and to the south or southeast at Site 3. During incoming (flood) or outgoing (ebb) tides, the water tends to move towards a channel, cut or low area in the reef flat where ',the majority of the water mass is entering or leaving the reef. This strong. tidal flow usually overpowers the wind-driven water movement unless they happen to be in similar directions. This is particularly evident at Site 2 whe re the cut in the reef accounts for much' of the water flow iInto and out of the eef flat. Water movement was generally faster during periods of high tides than low. The rate of water movement ranged from 0.1 mh@ec (0.19.:kn) to 0.35 m/sec (0.68 kn), with a mean of 0.13 m/sec (0.25 kn). During low tides, slack water (no tidal movement) or light trade winds, water movement along the reef flats was generally slower. At times, there was little. or no water movement due to light winds and/or minimal drainage of the reef flat during low tides. When dye was released during these conditions it would either move very slowly or eddy in a circular pattern showing very little if any along shore movement. Water movement at low tides and light wind conditions ranged from no movement to 0.12 m/sec (0.23 kn), with a mean of' 0.07 m/sec (0.13 kn). 66 Direction of water movement at Site 2 averaged 2650 (westerly movement), with the majority of the dye releases traveling parallel to the shoreline. The only exception to this general pattern was when a dye release was close to the cut (boat channel) in, the reef during an outgoing tide. Water movement at these times was towards the cut-,' but only if the dye release was very close (a few meters) to the channel. Dye release studies at Site 3 also showed strong along sho re movement, average 0 with an direction of movement at 1700, almost.due 'south. More eddying was observed at this site, especially in dye releas@.s that were located midway between the shore and the reef crest and' during periods of low tides.. This was probably due to Site 3 being both. shallower and wider than the reef flat at Site 2. Water Quality Review of literature indicates that very little chemical-W.ater quality data exists from Bahia Laulau. Simple physical water quality parameters such as temperatu: r'e have been evaluated in this report and salinity is the only chemical parameter examined in this study. Early discussions with the CNMI Department of Environmental Quality resulted in the expansion of their water quality monitoring program to include approximately 10 stations in Bahia Laulau. This program began.in January 1983 by examining marine waters in Bahia Laulau for total and fecal coliform bacteria. Marine waters were sampled in Bahia Laulau for fecal coliform on February 16, 1983. Ten (10) stations were monitored from the south end near the quarry below the runway and north to the extent of vehicle passage (Figure 13). The following are results from this initial survey. 67, LOCATION TOTAL COLIFORM FECAL COLIFORM South end of Laulau Bay (Unai Tuturan) 10 0 61 m (200 ft) North of (Unai Tuturan) 32 0 61 m (200 ft) North of #2 near ditch 18 10 Farm Area 6 0 30 m (100 ft) South of cave near center of Bay 12 2 91 m (300 ft) South of old Laulau Lounge 15 2 30 m (100 ft) South of old Laulau Lounge 24 4 Adjacent to old Laulau Lounge 30 20 30 m (100 ft) North of old Laulau Lounge TNTC 66 61 m (200 ft) North of old Laulau LoungeTNTC 17 NOTE: TNTC Too numerous to count Refer to Figure 13 for location of sampling sites Total and fecal coliforms are counted as a number' per 100: ml of water collected. Normally, in high quality water, coliform count is e.*X*.tremely low since these bacteria are an indication of unsanitary conditions. The preceeding table indicates that marine waters from the majority of stations sampled are clean.. Stations near the northern sector of Bahia Laulau suggest polluted conditions which can be traced to a farm located nearby. Most likely, farm animal wastes are being washed down to the bay where total coliform counts :,are too numerous to count and fecal coliform counts increase radically over other stations sampled. DISCUSSION AND CONCLUSIONS As one would expect, weather conditions in the Bahia Laulau. area are consistent with prevailing conditions of the sbuth-central Marianas. Although no actual temperatures were taken in the Bahia Laulau area, it is tropical with a uniformally warm climate and a high average relative humidity. A recent 10 year rainfall average at the Coast Guard Station in San Antonio measured 76.6 inches annually. Winds in the Bahia Laulau area follow the prevailing east-northeast direction at an average 10 - 12 kn (8.7 10 mph) during the period November to April. Wind direction remains easterly to northeasterly during the summer months, May October, but drops considerably to an average 6 kn (5 mph). Tropical storms generated in the Western Pacific typhoon belt have a strong possibility of. passing near Saipan. In the vicinity, these storms move from the southeast to the north- west. B ahia Laulau is directly exposed to powerful typhoon generated winds and waves. Evidence of these previous storms can be seen where heavy boulders, mooring buoys and other debris have been thrown up on high ground.. Bahia Laulau is a deep bay approximately 731 m (2,400 ft) :midway on a line between Hagman and Dandan Points. Deeper depths e:xist further offshore in the direction of the Marianas Trench. These depths :so close to shore represent a significant resource in terms of OTEC development and energy production. Offshore oceanic temperature follows a well-defined profile typical of the Western Pacific, i.e., a warm well mixed surface layer of nearly constant temperature (28.40 C, 83.40 F), a deep thermocline region (150 229 m) (500 - 757 ft) of decreasing temperatures (22.51 - 7.40 C) (72.50 -.45.30F) and a deep (525 -550 m) (1.,700 -1,800 ft) layer (6.40 - 4.40 C) (43.60 39. 90 F) . These depths and corresponding temperatures represent one of 69 the most significant temperature differentials in the world close to shore and suggest -a strong possibility for OTEC development at@ least: from the perspective of physical paramaters alone. Currents offshore of the 100 fathom contour (600 ft) f ollow an overall circular pattern with water entering the bay from the northeast splitting apart at Dandan Point. Water entering the' bay for istent and ms a, cons strong clockwise pattern within the center of Bahia: Laulau.' 'The leading edge of the water mass moves along or near the 100 fathom :c6ntour emerging with oceanic water at Hagman Point. Inside the 100 f a thom contour currents are more complex and seasonally variable influenced more by the prevailing wind an,d seas. Studies indicate that this current runs- counter to the prevailing. clockwise outer current following the shoreline and creating small eddies here and there. Currents inside the reef flat are ..'main ly influenced by surface winds, tidal movements and water depth'.. W_i@ter movement is almost always parallel to shore except where incluenced b Y a: channel, cut or low area., Water@ @quality in the bay appears to be excellent o'vera.1.1 except where localized pollution exists. Only total and fecal coliform, an indicator of animal wastes, have been evaluated nearshore. Other common water quality parameters are to be initiated in the area by the CNMI Department of Environmental Quality. 70 LITERATURE CITED CNMI Department of Environmental Quality. Water Quality Monitoring Program. Craig, H.L., Jr., H. Michel, T. Lee, S. Hess, R. Munier and M. Perlmutter. 1977. Selected data sets for a potential OTEC site: Guam (manuscript) (N.P.) Gregg, M.C. 1973. The microstructure of the ocean. ppl57-169. In H.W. Menard. 1977. Ocean science. W. H. Freeman @and Co., San Fra-ncisco. Hinz, Earl R. 1980. Landfalls of Paradise: , The guide to Pacific Islands. Western Marine Enterprises, Inc. Ventura, Calif., 93002. Lassuy, D. R. 1979. Oceanographic conditions in the vicinity of Cabras Island and Glass Breakwater for the potential development of ocean thermal energy conversion on Guam. Univ. of Guam Marine Lab. Rept. No. 53. U.S. Department of Commerce, National Climatic Center. 1981. Local climatological data, Guam, Pacific Federal Bldg. Asheville, N. C. 28801. U.S. Naval Oceanography Command Center. 1983. Annual Tropical Cyclone Report. Joint Typhoon Warning Center. Comnavmarianas., Box 17, FPO San Francisco, 96630. U.S. Naval Weather Service Command. 1971. Summary 'of synoptic meterological observations, Hawaiian and selected north Pacific Island coastal marine areas, Volume 5, area 14, Saipan. Williams, J. 1962. Oceanography. Little, Brown and Co. Boston (242 pp). 71 TERRESTRIAL FLORA AND FAUNA FLORA INTRODUCTION Prior to this study very little, if an: scientific%. work had been undertaken on the identification of flora in the Bahia Laulau a-e@a. In fact, very little botanical data had been collected from all of: Saipan until recently. Major works such as Fosberg (1960) and Stone (1970:). dealt primarily with Guam, although mention is made in each of these works regarding the general vegetation of the Marianas. Recently, however, a ieam of botanists from the U.S. Forest Service along with Margie Falanruw have@:been mapping the vegetation of Saipan. Bahia. Laulau is a highly diverse region of Saipan in terms of vegetation. Within the bay can be found nearly every ty"pe of vegetative cover existing in Saipan from savanna grasslands,@ to the' unique beach strand and'. into the climax hmestone forest. Because-of the, Bay's southeast exposur .e,@portions of the bay (Hagman and Dandan Points. and portions of the coastline out to these points) are depauperate and poorly vegetated. Only the most tolerant forms of vegetation florish here. It is evident that the composition of vegetation on large.'parcels of land, particularly on the Hagman and Dandan promontories, has been totally modified from the original or climax stage of development. This is true for much of Saipan and is the result of wartime activities. Both the Hagman and Dandan promontories were sites of military air installations which required extensive clearing operations. Bombing and subsequent burning in these areas have left scars on the vegetation that may never allow it to return to its natural climax state. Relics of ancient Chamorro villages and farms in the LauLau area a.1so indicate the. drastic modification of vegetative cover 72 from primary to secondary in nature. In spite of the scars left by historic and wartime activities, the area is highly diverse and represents a truly tropical setting. METHODS Maps, aerial photographs, photography by boat and from prominent vistas provided information on the general type of plant community and where transects should be located. Four (4) study area were established in the vicinity of each project site (Figure 13). Transects within study @Lreas were chosen so as to represent a cross-section of the flora in the vicinity of each site. Transects at each site represented the same area covered and the sampling period was similar at each site. Species lists and counts were made during transect walks withini study areas. Sampling occured on four field. visits (11/82, 2/83, 5/83 and 9/83) and each site was evaluated twice. Relative abundance was calculated for each species as an indicator of its in compo sition. The following. categories were used: ABUNDANT - Indicates the number of individuals of that species is greater than 500 COMMON - Indicates the number of individuals,of that species is greater than 100 but less than 500 SELDOM - Indicates that the number of individuals of that species is greater than 10 but less than 100 RARE - Indicates that the number of individuals of that species is less than 10 This method does not provide statistical data like quadrats or nearest-neighbor programs would. Nonetheless, these relative values are more than purely subjective since they are based on actual counts.. 73 RESULTS Site 1 Flora at Site 1 is comprised mostly of 1o.*w scrub forms dominated by Leucaena::leucocephala (tangantangan) and Misca, nthus floridulus (s:wordgrass) d (Neti) Other common forms in the vicinity' are a variety 'of@ shrub like plants, small trees or vines, i.e. Colubrina asiatica (Ga'sos'o), Bikkia mariannensis (Gausali), Cassytha filiformis (Mayagas) Cleroden'drum inerme (Ladugao), Myrtell bennigseniana. Common weeds'. grasses; and:: ferns include. Bidens pilosa (beggar's tick), Dimeiia chloridifoTmis'': (grass) and Dicranopteris linearis (savannah fern) (Mana). A f ew 'larger trees are scattered. about but considered rare in the vicinity of Site Usually these trees are:. clumped' together in one area and include the following: Casuarina equisetifolia (ironwood) (Gago), Pandanus fragrans (Kdfil) and Pandanus dubius (:andanus) (Pahong). P Environmental pressure at Site 1 is intense due. to he.avy and constant winds and, waves causing the air to be filled with salt, spray. These conditions:. beat down the flora considerably and only the', mosit' resilient plants flourish here. This accounts for the low profile of vegetation' at this site. Sites 2 and 3 Flora at Sites 2 and 3 is quite similar and for this@.,reason they are discussed together. Flora found at Sites 2 and 3 can, be typified as associates of the limestone or modified-limestone forest. The limestone forest on either side of the access road is typical of the central valley portion of Bahia Laulau. Limestone forests are dense and variety is extreme. It is difficult to identify a particular form as dominant; however, numerous forms are common. In addition, this limestone forest is considered modified in the vicinity of the road and along the beach strand: since these are transition zones, either man-made or natural, in the succession of the forest. 74 Low limestone areas called terraces typify the central' coastline of Bahia Laulau. Harsh conditions prevail due to high evaporation rate, rapid water drainage and exposure to salt spray. Pemphis acidula (Nigas) is abundant nearest the ocean. This is followed by Scaevola taccada (Nanaso) and Messerschmidia argentea (Hunig) a small tree. Away from the water are found Pandanus sp., Hibiscus tiliaceus (Hibiscus).. (Pago) and Ochrosia mariannensis (Langiti). Bikkia mariannensis (Gausali) is a common form found on steep cliffs. Further back in the limestone forest we fihd larger trees comprising the upper story of the forest. These forms include Artocarpus sp. (breadfruit) (Dugdug), Ficus prolixa (banyan) (Nana), Cocos nucifera (coconut) (Niyog), Ochrosia mariannensis (Langiti) and Mammea odorata (Chopak). Various smaller forms, either lianas, epiphytes or.weeds make up most of the understory vegetation. These include the following: Leucaena leucocephala and L. gaumense (tangantangan), Hibiscus tiliaceus: (Hibiscus) (Pago), Pluchea indica, Neisosperma. oppositifolia (Fago), Cycas circinalis (cycad) (Fadang), Davallia solida (fern) (Pugua Machena)-, Caesalpinia major (Ife) , Piper guahamense (wild piper) (Pupula-ni-Aniti) , Phymatodes scolopendria (kahlao) , Morinda citrifolia (Indian mulberry) (Lada), Psychotria mariana (Aplokatina), Tripbasia trifolia (limeberry) (Lemon-China) and Cestrum diurnum (China inkberry) (Tintan-China). Sites 2 and 3 also include a ravine community dissecting the upper savanna forming valleys and gullies in which water and moisture accumulates. Although the flora varies slightly, one always finds Hibiscus tiliaceus (hibiscus) (Pago), '.Cycas circinalis (cycad) (Fadang), Areca cathecu (betel-nut palm) (Pugua Machena), Ficus prolixa (banyan) (Nana)', several lianas and numerous epiphytes such as ferns. 75 Beach Strand Since these islands are'small, nearly all @vegetation can be considered "strand. vegetation." However,. in the context' of this report it is taken to mean those plants most often found growing in the immediate vicinity of the sea. With very few exceptions, plants growing on the strand can be found elsewhere on Saipan. However, not as a dominant form like on;the strand. Within central Bahia Laulau, as in most strand communities, numerous trees grow close to the sea and provide deep shade, where: mosses, ferns, hanas and epiphytes of many kinds abound. Some. of 'these-1arger trees include the. following: Casuarina equisetifolia (ii@onwood) (:Gago), Messerschmidia argentea (Hunig), Hernandia nymphaeifolia (Nonak), Cassytha filiformis: (Mayagas), Thespesia populnea (Banalo) an*d',, Cocos nucifera (coconut)@ (Niyog). Smaller forms of vegetation- can be found in the understory shaded by the larger trees or growing out in the open along the beach. U.nderstory shrubs and bushes include the fpllowing: Scaevola taccada @.(Nanaso), Pluchea indica, Desmodium umbel'latum'.(Palaga Hilitai) , Sophora tome .ntosa, Colubrina asiatica (Gasoso),. Bikkia', mariannensis (Gausali), Allophylus timorensis (Nger), Triphasia trifolia (limeberry) (Lemon China) and Cestrum diurnum (china inkberry) (Tintal n- China). A few plants obviously more salt tolerant than others grow out. along the beach as vines and creep toward the water. These include the following: Ipomoea pes-caprae (beach morning glory) (Alalag-Tasi), Wedelia biflora (beach sunflower), Vigna marina (Akangkang Manulasa), Clerodendrum inerme (lodugao) and Abrus precatorius (coral bean) (Ko'lales). Where rocky outcrops exist (Sites 2 and 3) or where rugged uplifted limestone forms a border between the ocean and the inner coast, very few plants are found. Environmental conditions are extremely harsh here. In these strand areas 76 Pemphis acidula (Nigas) provides a thick cover along a narrow band near the shore. Along the highly exposed shore this plant is scrub-like and bent shoreward with gnarled trunks and twisted roots :solidly embeded in the limestone. Site 4 Flora at Site 4 is dominated by a thick cover of. Leucaena leucocephala (tangantangan). Also found in this section of Bahia Laulau is the local tangantangan Leucaena insularum var. guamense. Associated with the thick cover of tangantangan can be found various weeds, grasses and vines i.e. Bidens pilosa (beggar's tick), Stachytarpheta indica (false verbena), Mucuna gigantea (small seabean) (Gayidikike) and Clerodendrum inerme (Lodugao). Pemphis acidula (Nigas) also provides a thick cover along the coastline here.' A few small, shrubs stand out here and there but not in great numbers. These include: Colubrina asiatica (Gasoso'), Bikkia mariannensis (Gausali), Triphasia trifolia (limeberry) (Lemon-China), Cestrum diurnum (China inkberry) (Tintaln-China) and the small fern Dicranopteris linearis (Savannah fern) (Mana). Acomplete- checklist of flora by site is given in table 6 (Appendix A). DISCUSSION AND CONCLUSIONS Diversity and species composition of flora at site s two and three are quite similar, this being the only major similarity between the four sites. A very well defined limestone forest covers the majority of central:]3ahia Laulau and comprises the majority of species found at these two sites. Each of the other two sites (one and four) are unique in terms of species composition but diversity is low compared with the sites in central Bahia Laulau. Comparatively speaking, sites one and four are depauperate as a result of intense environmental pressures i.e. high winds and surf, salt 77 air an d rugged terrain. Sites two and three are protected from harsh environmental pressures which seems to allow'for greater diversity. Table 6 (Appendix A) is a checklist of flora from Balt@,ia Laulau. Scientific names are given in each case with associated common and Chamor ro .names where appropriate. On the whole the flora of Bahia Laulau can, be characterized as a highly diverse botanical community having' lush limestone fo*rests, upland savannah grasslands and low scrub rocky, clif f swith,7 modifications where human, activities existed or now exist. Major modifications iare evident at. Dandan and Hagman Points where wartime activities existed. 78 LITERATURE CITED Fosberg, F.R. 1960. The vegetation of Micronesia. .'Bull of Am. Mus. of Nat. Hist. Vol 119. Stone, Benjamin C. 1970. The flora of Guam. Micronesica 6:1. 79 FAUNA INTRODUCTION The fauna of Saipan has not been well' defined, particularly in the Bahia Laulau area and other areas along the east coast of. the,iPland. The avifauna has been described by Baker (1951) and more recently by Owen (1977). Additional recent accounts of the avifauna ha.ve' mostly. 'concentrated in the lake Susupe and wetland areas of the island (Shalleinber er an d Ford, 9 1978 and Tenorio and Associates, *1979). In his checklist of the birds of Micronesia, Owen (1977:) lists atotal of 91 species reported for the Marianas. These include residents, migrants, vagrants@ and introduced species and take into account all. -reliable records known 1or' the area up to 1977. This compares with his listing of 191 species reported -for all of Micronesia. Although no overall or island-wide study has@ b ee' npublished on Saipan's 'birds., the wetland regions, especially the lake Susupe area, have been fairly '.well documented. Shallenberger and Ford. (19,78)'. recorded a total of 30 species of birds within the lake Susupe area.- These included migratory w1aterbirds, seabirds, marsh associated species aIs well as several birds commonly found in the limestone forest areas of Saipan@ In an ornithological survey of the wetlands of Saipan (Tenorio and Associates, 1979), the investigators observed a total of 28 species of birds in the seven study 'sites, with the lake Susupe site being the most diverse with 19 species. 'This report described Saipan's overall bird population as stable and in good condition in terms of species diversity, geographic distribution and general population levels. Tenorio and Asso. (1979) observed a total of three species that were currently on the endangered species list. These 80 included the Marianas Mallard (Anas oustaleti), Nightingale Reed-warbler (Acrocephalus luscinia) and the Micronesian Megapode (M@egapodius laperouse). Eighteen genera of terrestrial reptiles are known from Micronesia (Brown, 1956), with the greatest variety being in the: skink (Scincidae) and gecko (Geckonidae) families. The most common skink is a small brown species (Emoia sp) and this was observed at all sites.* Other common skinks are the blue-tailed variety (Emoia cyanura) and a larger, green-tailed skink (Lamprolepis smaragdina). A few Anole (Anolig carolinensis) were observed. Three species of rats and one species of mouse are known from the Mariana Islands, and all are widely distributed throughout the islands. The Norway rat (Rattus norvegicus) is found mostly in urban areas of the islands, but may be present in the limestone forest areas of, Bahia Laulau. METHODS The fauna of Bahia Laulau was sampled along the shoreline,: along four transects. perpendicular to the beach into the -forested areas of each site and from vehicles along the access road. Sampling was conducted during the early morning (sunrise to one hour after sunrise), daytime and early evening (one hour before and until sunset). This would insure that the time of greatest activity for all animals, particularly birds*,:' would be observed and sampled. All transects were sampled three times,', November 1982, February 1983 and September 1983. The transects sampled are the same as those used for the flora investigations (Figure 13). All animals were censused by naked eye sightings and a checklist of all species was made. W.alks were made along the transect at a reasonably slow pace. Rocks were turned over and tracks were noted for signs of animals not usually seen. In the case of birds, binoculars were used to verify sightings along with audible calls to identify those not actually seen. 81 Frequently, in the dense vegetation, it is impossible to see many animals particularly birds. However, approximate numbers can be* estimated by auditory means. Because of the adequate numb, ers of birds observed at each site, relative abundances were used in conjunction with the* checklist. Calculating densities and actual abundances statistically would'have required more transects and replicate counts, neither of which -were practical for the scope of work. In addition, many birds in the tropics are: difficult to quantify due to their secretive behavior, low numbers and: habitat preference (dense vegetative cover). For a measure of relative abUndan'ce of birds, four categories were used: (A) Abundant- The species was noted in numbers greater than 20 (C.) *.Common The species was noted between 10 and 20: times (0) .0* ccasional - The species was noted between 3 and.'.:9, times (R) Rare The species was noted I to 2 times In addition, based on habitat and birds previously recorded from the Marianas, -.a species was noted as expected (E) to occur in: t.he area if it was not actuall: observed or heard but was thought likely to@ occur if more Y Y. intensive s@a.mpling were done. RESULTS Avifauna Table :7 (Appendix A) includes a checklist of all species of birds observed or heard at all study sites including the access ro ad that runs along Bahia Laulau and includes species that were not observed or heard but that could reasonably be expected to be found at the sites. The avifauna was surveyed from the beach and shore area landward to the more densely vegetated forest area. All sites were surveyed a minimum of four times, including early morning, midday and late afternoon times. 82 The total number of species actually observed at all sites was 29, with a total of 34 species observed and expected to occur in the bay area. All sites were similar in total number of species observed with the exception of Site 4, where only 13 species were observed. This is not unusual since Site 4 respresents the smallest site area and contained rewlatively few shorebirds since the beach and reef flat areas were also quite small and limited in space. Vegetation is also less diverse at Site 4 accounting for fewer species of birds. The low-profile vegetation at Site 1 likely accounted for the second-lowest number of species being sighted there (17 species). The most abundant bird species encountered at the four sites include the Fantail (Chichirika), White-eye (Nossak), Philippine Turtle-dove (Paluman senesa), Eurasian Tree Sparrow (Gaga Pale') and Noddy Tern (Fahang). Species that could be considered common for the bay area include the Yellow Bittern (Kakkag), Collared Kingfisher (Sihig) , Cardinal Honeye.ater (Egigi), Golden Plover (Dulili), Starling (Sali) , White Tern (Chungew) and the Reef Heron (Chuchuko). Reptiles and Amphibians The blind snake (Typhlops braminus) has been 'recorded from Saipan but none were seen during this survey. There are no records of the Philippine rat snake (Boiga irregularis) in the Marianas, although it is very common on Guam. In March 1983 a Saipan resident killed what as believed to be a rat snake but was later identified as a California bull :s n' ake. The snake probably arrived aboard a ship or was transported as a pet from the U.S. The largest reptile in the Marianas is the Indian monitor lizard (Varanus indicus). Originally introduced by the Japanese to con trol rats, the monitor lizard has spread throughout Guam and the Marianas. It reaches a length of 5-6 feet and has had a negative impact on the native bird population since it eats eggs and the juveniles. Chicken farmers regard the 83 monitor lizard as a pest which is hunted and killed regularly if seen around farms. Three individual monitor lizards were observed in the; f 6're'sted areas surrounding Bahia Laulau and two more were seen on the access: road during the early@: morning hours. The most widespread amphibian in the Pacific Basin is the'. giant marine toad (B U@fo marinus). These are more common around lakes,@ :swamps and marshes, but are also commonly found within 'limestone foiests@ a*nd in areas of dense tangantangan growth. Their abundance increases! dramatically as the rainy season arrives, which triggers their reproductive 'response and provides standing water for the tadpoles. This toad was' 'seen at each.' of the study sites particularly at Sites 2 and 3 and, along the access.r,oad. Mammals Both the: roof rat (Rattus rattus) and the Polynesian ra't..':',(Raitus exulans) were observed in the study area and these are the..'two. ffiost common rats found on. Guam and in the Mariana Islands. Rats can climb and often are seen in tr6es,, especially the larger roof rat. They are. considered potential predators @of bird eggs and small birds, especially those species that build their nests' ;@on or near the ground. Mice (Mus musculus) are common around residences in Saipan and would be expected in the lirrie stone forest and shoreline areas within the study site. The musk shrew (Suncus murinus) was originally. introduced to Guam and has since spread to Rota, Tinian and Saipan (Shallenberger and Ford, 1978). They live' near human habitations, in secondary growth and can be found in both swampy as well as grassy and rocky habitats. They are likely found in the vicinity of Bahia Laulau although none were observed. Feral dogs (Canis familiaris) and cats (Felis catus) and pigs (Sus scrofa) are found throughout the islands although they tend to inhabit areas bordering more densely urbanized, zones or near family dwellings and/or 84 f arms. A few dogs were seen in the survey site but no cats were observed during the study. Habitat conditions, especially in the limestone jorest areas of Sites 2 and 3, are favorable for reasonable populations of pigs. Based on current field observations and information from wildlife biolo gists from the Division of Fish and Wildlife and local interviews, wild pigs are:not present on Saipan. They say it appears that wild pigs have been absent for many years. However, it is likely that escaped or loose domestic pigs or descendants of domestic pigs that have interbred with the oi-iginal. wild stock many years ago roam the limestone forest areas of Saipan. A few observations in the limestone forest of Bahia Laulau (shoreward at Sites 2 and 3j revealed holes that.were dug-up or rooted by some kind of animal. Although there are typical, signs:of pigs searching for food, the holes could have been made by another.animal. Since no pigs were actually observed and based on the field work. by. local Fish and Wildlife biologists, the pig is not been *,included in the checklist of fauna for the Bay. The: Marianas or Sambar deer (Cervus unicolor -mariannus) is an inhabitant of the limestone forest regions throughout Saipan. The cliff line areas surrounding Bahia Laulau provide excellent habitat for this@ animal and signs indicative of deer and pig were observed in various locatio.n:s, although no animals were actually seen. Possibly the only true native mammals in the Mariana Islands are the bats. The Marianas fruit bat (Pteropus mariannus) is found 6ft.' Saipan in limited numbers. Populations have declined drastically and their status is in question. @However, -it is still hunted illegally as a source of foo'd:: since the Guam and Marianas bats are considered a delicacy and are preferred over bats from other islands'. such. as Yap and Palau. No fruit bats were observed around the cliffs of Bahia Laulau. However, the habitat and suitable foods 85 are present there. Since bats move about from area to area, either in small groups :or larger colonies, it is reasonable to expect that fruit bats do frequent this area from time. to time. The' most likely areas' would be between sites 1 and 2, along the cliffline and"inland to the limestone forest. The status and occurence of the insectivorous bat (Emballonura' semicaudata) is unknown on Saipan at the present time. DISCUSSION AND CONCLUSIONS In general, Saipan has a relatively healthy bird population, especially island. the in the more densely vegetated limestone forest areas@ o Compared to Guam, Saipan avifauna is more diverse and numerou's even though the 'total land area is smaller. This is due in. part. to a smaller human. population, less developed areas (urban sprawl)', f ewer natural P, predators (rat snakes, feral dogs and cats) and possibly, ,fewer pesticides and diseases within the environment. Birds'. represent the most abundant type of fauna in 'ithe Bahia Laulau area with@. total of 29 species observed out of an expected- 34. All sites were similar in total numbers with the exception of Site '-4. where only 13 species were observed. However, this site was the smallest in size and is relatively depauperate of flora. At the present time, CNMI regulations require a hunting license for the taking of birds. The legal hunting season runs from July 1 through July 31. The following species may be taken: Philippine Turtledove (bag limit 10, season limit =40); Ground Dove (bag limit = 2, season 'limit = 6); Fruit Dove (bag I ,Imit = 3, season limit = 9); and the Micronesian Starling (bag limit = 10, season limit = 40). The blind snake Typhlops braminus, although not seen at any of the study sites, is expected to occur here. It has previously been recorded from Saipan. There is no evidence that the larger Philippine Rat Snake 86 (Bioga irregularus) exists in the area although it. is common on Guam and likely to be found in other islands of the southern Marianas. A total of five monitor lizards (Varanus indicus:) was observed in the limestone forest region of Bahia Laulau. These individuals were at least two feet in total length but less than three feet. It was. extremely difficult to get near these animals as they are not accustomed to:being around humans. The common marine toad (Bufo marinus) was found in abundance particularly in shaded, forested or damp areas of the bay. They were observed at all four sites and were particularly abundant at Sites 2 and 3. We did not notice a large population increase during the rainy season due to the dryness experienced during 1983. However, populations of this toad normally increase dramatically when the rainy season arrives triggering the' reproductive. response. A number of mammals common in the southern Marianas were observed. The roof rat (Rattus rattus) and the polynesian rat(Rattus exulans) were observed on the ground and in the trees-. Numerous feral dogs were -observed in the area. These animals may belong to.a land owner@in the area and it is common for them to run wild. Areas surrounding the bay are open to hunting and it is suspected that a reasonable amount of illegal hunting also occurs in the limestoh6 forest and cliffline habitats. Both deer and pigs may be hunted with aJicense f rom September 1 through December 31. The bag and season limit for @:deer is one (1), while. for pig the bag limit is two (2), with a season limit of six (6). The'. Marianas fruit bat (Pteropus mariannus) is found on.. Saipan in limited numbers. Although the population on Saipan is not included in the Federal Endangered Species List, populations have declined drastically and their status is in question. It is estimated that the total population on Saipan is less than 50 individuals (Division of Fish and Wildlife). 87 LITERATURE CITED Baker, R.H. 1951. The avifauna of Micronesia, its origin, evolution and distribution. Univ. of Kansas Publ., Museum of Nat. History, Vol. III, NO. 1., 359p. Brown, W.C. 1956. The distribution of terrestrial reptiles in the Islands of the Western Pacific Island Basin. Report of XIII Pacific Stience: Congress. Owen, R. P. 1977. A checklist of the birds of Micronesia@ -Micronesica; 13:65-81. Shallenberger, R.J. and J.I. Ford. 1978. Report, field trip to' Guam and Saipan, 13-23 December 1978. U.S. Army Corps of Engineers, Hawaii. Unpublished. Tenorio, J. C. and Associates, Inc. 1979. Ornithological survey of wetlands in Guam, Saipan, Tinian and Pagan. Prep. for S-. "Army Corps of Engineers, Pacific Ocean Division. 20.2p. Unpublished. 88 89 MARINE FLORA AND FAUNA MARINE PLANTS INTRODUCTION Marine plants have been studied in the Saipan Lagoon, (Fitzgerald et al. 1974) and (Tsuda et al., 1977 a and b). However,: these studies did not concern themselves with the Bahia Laulau area. The only. previous work on marine . lants in the Bahia Laulau area is a very brief mention,:by Cloud in p the Military Geology of Saipan. METHODS. Reconnaissance dives were made at all sites utilizing' snorkel and/or scuba '.equipm ent during November 1982. Where conditions' permitted, semi qu antitativ e 100 m (328 ft) transects were established 6rpendicular from p the shore! (Sites 2 and 3 only) . These data refle ct changes in algal distribution, (Table 8) but do not reflect percent cover.or, density. For puirposes of this study, turfs were considered to be any marine algae whose:'@'@ growth form produced a low relief uprigh .t habitat. Species of red algae, especially in the orders Gelidiales, Corallinales and Cryptonemiales were the principal turf formers. Turfs provide both microhabitats and substrata for numerous epiphytic plant and animal taxa. In contrast to turfs, larger fleshy algae made up the overstory, e.g., Sargassum. and Galaxaura species. RESULTS During this survey sixty-nine species of marine algae representing four divisions were recorded. One species of seagrass, Enhalus acoroides, was also recorded. A list of the recorded taxa can be found in Table 8 90 (Appendix A). Two narrow fringing reefs (Sites 2.and 3)', one reef margin and reef face (Site 2), three shallow submarine terraces (Sites la,.2 and 3) and two deeper submarine terraces (Sites I and 4)..: were investigated. A range of habitats including sand floors, reef flat holes, cryptic overhangs, vertical walls and limestone terraces were present at tlie various sites. Site 1. Site 1 was characterized by a scoured and rubble strewn submarine topography. Only 15 species of algae were recorded. Red algal turfs composed chiefly of Gelidium species predominated. The blue-green algae, Microcoleus lyngybaceus and Schizothrix' calcicola were. also abundant. Scattered patches of Galaxaura, Mastophora and Neomeris species were observed in crevices and overhangs. In general, this site can be described as extremely depauperate. Site la. Site la is located in a protected area' surrounded by steep limestone cliff sand narrow cut benches. This area was very calm and quite luxuriant in marine life. A highly variable topography and rich:coral com- munity provided a variety of habitats for benthic algae. Thirty-seven spe- cies were. recorded, 14 of which were green algae. Patches of Chlorodesmis fastigiata and Bryopsis pennata were particularly common. Low*.* relief turf forming coralline algae, especially Amphiroa species were abundant and provided a substrate for many epiphytic red and green algal species. Cryptic species such as Boergesenia forbesii and Dictyosphaeria. versluysii were common as well. Site .2. Site 2 consists of a narrow reef flat (approx. 150 ;'m, 482 ft wide-) cut@.. by numerous surge channels extending through the reef margin. In addition to general reconnaissance dives, a perpendicular transect was set up across the reef flat, reef margin and submarine terraces to a depth of 91 10m (33 ft) The submarine terrace transect parallelled an old pipeline. Calm surf conditions permitted work on the reef margin and face., The reef flat was divided into an inner and outer zone. Because of its narrow width and windward exposure, it did not exhibit the-sha.ip zonation pattern s characteristic of wider windward flats'. The substrate consisted of scoured limestone coral rubble and sand with scattered holes@ :and Porites colonies. In the inner zone, small patches of the seagrass Enhaltis acoroides were found in, association with several other species of, :algae, notably, Sargassum polycystum, Turbinaria ornata, Dictyota bartay:resii:: and :Padina minor. These patches varied from 1 - 3 m (3. 3 - 9. 8 ft)@ in'width. S' .coured and rub.ble-strewn surfaces had sparse turf consisting @f Cladophoropsis membranacea and Amphiroa fragilissima. Occasional' clump, s, of Halimeda opuntia and Mastophora rosea were noted in sandy areas. Neomeris ahnulata was patchily abundant on coral rubble. Vertical walls in sand holes contained additional species. The outer reef flat was covered by a more luxuriant*. turf consisting of Amphiroa fragilissima' and "A. foliacea in association '.with Cladophoropsis membranacea, Gelidiella acerosa, Sporolithon sp... Porolit hon sp., and Mastophora rosea. Five species of Caulerpa were recorded. Patches of Sargassum cristaefolium were also 'abundant in this area. In all, 33 species of marine benthic algae and one species of seagrass were noted.on the reef flat. The reef face and submarine terrace habitats were characterized by a diverse assemblage of algae totaling 54 observed species. Turfs, as well as overstory species were interspersed among corals. Cover ranged from approximately 20-100 percent (or greater in selected areas). Rich turfs of Amphiroa fragilissima, A. foliacea, Cladophoropsis membranacea, Boodlea composita intertwined with five Caulerpa species, Tolypiocladia glomerulata, 92 Levielle_@ jungerm nnioides and others were luxuriant. Lar ge patches (1 m, 3.3 ft or more) of Halimeda opuntia and Mastophora rosea were also common. Three species of Galaxaura were noted as were Chlorodesmis fastigata and Bryopsis pennat In general, the variable terrai n: of the site provided numerous types of habitats for algal species in addition to corals and other marine organisms. .Site 3. Site 3 consisted of a very narrow reef flat (approx. 100 m, 328 ft wide). Large waves prevented access to the reef margin and face although these habitats are probably comparabie to those studied at Site 2. In addition to reconnaissance divest a transect was'established on the reef flat. A subtidal reconnaissance dive was also made to 10 m (3.3 ft). Because of its narrow width and uniform topography, the -reef flat did not exhibit sharp zonations typical of more extensive reef flats. Large expanses of sand and coral rubble alternated with stretches of scoured 10 m (3.3 .33 ft) sea limestone and Porites colonies. From 1 ward of the rom 10 50 shoreline:". only occasional patches of Padina minor were noted. F m (33 164 ft) out, patches of the fleshy brown- algae. Sargassum cristifolium, Turbinaria ornata and Padina minor were more common, r accounting for approximately 25 percent of the surface cover An places. Beyond 50 m (164 ft), turf algae were dominant.. A combination of Cladophoropsis membranacea and Amphiroa fragilissima provided the sub strate for numerous epiphytic algae. The blue-green alga Schizothrix da'lcicola was ubiquitous,!, often overtopping the algal turfs and some larger species below. This- phenomenon is common during the winter (Nov-Jan) when minus tides and exposure create favorable conditions for opportunistic blue-greens. In the occasional reef flat hole or vertical surface of a coral head,. Halimeda opuntia and Mastophora rosea were common. The coralline red alga 93 Sporolithon sp. was also common. Gelidiella acerosa became progressively more. abundant on the outer reef flat, though it was consistently less abundant than Amphiroa fragili.ssima. Both are characteristic of high wave impact zones. The submarine terrace was accessible only by boat. One re c@onnaissance dive was made to depths ranging from 5 - 10 in (16 - 33 ft).;, Poor visibility and heavy surge limited the investigation at this site. in general, however, there was evidence that the area is seasonally calm. Deep su'i ge channels extended for long distances creating a labryinth of vertical walls and over- hangs. Seven species of the stoloniferous green alga Caulerpa were record- ed, often. in luxuriant carpets covering entire walls. Caulerpa filicoides and C. verticillata were especially dominant. Halimeda velasquezii and three -species' of Galaxaura were also common. Ceramium .gracillitim, Leveillea jungermannioides and Tolypiocladia glomerulata were common turf forms. A total of 45 .species were recorded. Site' 1.4. Site 4 consisted of a deep sloping submarine terrace with crevices, coral pillars and sand channels. One recon Inaissance dive was made covering depths from 10 - 20 m (33 - 66 ft). Conditions were so rough that even at 20 m (66 ft) the surge could be felt. The algal .community was remarkably similar to that'. seen at Site 2 though fewer species were recorded. Of particular interest was the abun- dant growth of a usually cryptic and uncommon green algal species, Rhipilia orientalis. Throughout the dive this was the visually dominant alga. In all 28 species of algae were recorded. DISCUSSION AND CONCLUSIONS Each of the five sites examined in Bahia Laulau presented somewhat different algal communities. This is largely a function of exposure to the 94 fetch of the open sea and local coastal topography. (i.e., 'reef flats vs. cut benches and cliffs). Sites 1 and 4 experience the most regular and severe disturbances due to their direct exposure to windward ground swells. Site la is the most protected area and Sites 2 and 3 'are seasonally variable. Moreover, Sites 2 and 3 have fringing reefs, while the other sites do not. Strictly from the marine botanical perspective, the:: algal communities are typical of those seen on windward exposures in the southern Marianas (cf. Pago Bay, Guam and bays south). With respect to reef flats, Sites 2 and 3 had very narrow reef flats and thus did not exhibit distinct zones of seagrass and the brown alga Sargassum. At Site 2 only small irregular patches of these taxa were pre- sent. Consistent with the narrow reef flats were the lack of moat develop- ment and other physiographic features that result in a -more patterned ben- thic algal community. However, the 33 and 25 species recorded respectively from these sites indicates a moderately high diversity, despite low percent cover (probably less than 5 percent in most places). It is important to note that seasonality is a critical factor in the distribution and. abundance of benthic algae on the reef flat. During the summer aind fall months, low tides, de siccation stress and exposure lead to massive die-offs and low percent cover. Ephemeral species can be expected to increase diversity slightly as the winter and spring seasons begin along with a'. concomitant decrease in blue-green taxa. However, percent cover and overall standing crop will. increase substantially. Based on the author's expe rience with similar habitats on Guam, by March and algal reef flat bloom will alter per- cent cover. to nearly 100 percent in many areas. A green carpet of Cladophoropsis species can be expected. This is a natural phenomenon and not an indicator of pollution.. 95 The submarine terrace algal communities at all the study sites reflected differences in response to various disturbance: conditions.. With respect to marine plants these are both physical and biological. Rough w ater conditions and barren substrate can inhibit algal recruitment and subsequent survival. Integrally, the presence of herbivorous grazing fishes and.echinoderms (for which there w as strong evidence, e.g., scrape marks. on .,rock s) may have further reduced the standing crop of algae present. Site I exemplified this situation. However, the presence of grazers can also enhance algal diversity g and standing crop depending on other ecological parameters.., Measurement of these factors is experimental in nature and was beyo.nd:the scope of this survey. :In general, however, Sites 2, 3 and 4 presented typically diverse tropical reef habitats, while Site 1 presented a high disturbance area result- ing in a depauperate seaweed community. .96 LITERATURE CITED Fitgerald, W. and W.J. Tobias. 1974. A preliminary survey of the marine P lants of Saipan Lagoon. 20p. Tsuda, R.T., and -W.J. Tobias. 1977a. Marine benthic algae from the Northern Mariana Islands, Chlorophyta and Phaeophyta. Bull. Jap. 'Soc. Phycol. 25 (2):49-64. Tsuda, R.T. and W.J. Tobias. 1977b. Marine benthic algae from the Northern Mariana Islands. Cyanophyta and. Rhodophyta. Bull. Jap. Soc. Phycol. 25 (3):155-158. 97 PLANKTON INTRODU'CTION Plankton has only recently been sampled:, or studied within,'- the Bahia Laulau area (Birkeland et al., 1984. in press). 'Plankton has been, sampled in other areas of the Marianas particularly Guam, Saipan and a few of f shore banks (Amesbury, 1978). Planktonic larval behavior and geographic distribution of coral reef asteroids in the Indo-west Pacific w as@ studied by Yamaguchi in 1977. The zooplankton of Tanapag Harbor. was. analyzed as p art of the marine survey of the power barge "Impedance": (Doty and Marsh, 1977). METHODS., Two @.each, horizontal and oblique, plankton tows were:,conducted from the M.V.@ Bahia Laulau on November 5, 1982. These t ow s were located offshore just to the north of site 2. On February '9-, May 10-11 and September''.29-30, 1983 a series of horizontal and oblique tows, were conducted offshore' at:@ all four sites. Refer to Figures 16 a,b,c,d for the location of all the plankton tows. Equipment consisted of a 0.5 m (1.65 ft) diameter plankton net with a mesh size of 0.020 inch (500 microns), 'a towing bridle and line and sampling jars. All samples were fixed in 5% buffered formalin. Horizontal tows were run just below the surface for a total of 5 minutes at a boat speed of four 3.5 kn (4 mph) during November 1982. Gusty winds and moderate seas prevented a slower tow speed. Oblique tows were started from a depth of 35 m (112 ft). For the February, May and September tows, a slower boat speed 1. 7 kn (2 mph) was possible and all tows'were run for a total of 10 minutes each. 98 RESULTS AND DISCUSSION Results of the plankton tows completed on November 5, .1982 and February 9, May 10-11 and September 29-30, 1983 are: shown in Tables 9-9c (Appendix A). For the plankton tows done during November:i Ahere was at least a three-fold increase in the total abundance of zooplankton collected in the surface tows than in the oblique tows. Mysids were the predominant taxa, representing 20 to 30 percent of the total number of zooplankton collected. All taxa except chaetognaths were more abundant at the surface than at the deeper depth (3.5 m, 11.5 ft). Other predominant taxa were calanoid d fish larvae. The fish larvae copepods, veliger capsules, shrimp mysis an were. predominantly members of the following families: Apogonidae, Gobiidae and one Sygnathidae larvae. Variation between tows was great for veliger capsules and calanoid copepods; however, patchiness is an intrinsic characteristic of plankton and it is a universal problem in sampling methods. The total composition of zooplankton is similar to the zooplankton collected off LuminaP, Reef, Guam, .another potential OTEC site. For the. eight tows conducted during Februar (4 surface and 4 oblique), the predominent taxa was the class Radiolaria. which comprised 94 percent of the total plankton collected (all tows). The class Co'p'epoda was the most diverse with 11 species. Although there were slight increases in total numbers of plankton and species diversity between surface ap d oblique tows., these differences were only significant at Sites 2 and 4. Site 4 showed almost a 15-@.fold increase in total numbers for the sur'face tow compared to the oblique tow. However, this was due almost entirely to a great number of Radiolarians.. The oblique tow, however, was more diverse 99 (11 species versus 9 species). At Site 2, the most diverse site sampled, the surface tow showed an approximate 33 percent 'increase in total numbers and one more species than the oblique tow. For..the four surface and four oblique tows conducted during May 1983, the predominant groups included invertebrate eggs (55.5 % @of the total plankton- collected), the class Malacostraca (mainly shrimp .mysis and crab zoeae, 14.3 class Copepoda (mostly Calanoid sp.,,,11.7 %),,ahd the class Cladocera (Evadne sp., 10.0 %). Fish eggs comprised less 'than' 1 % :of the total plankton collected. Species diversity did not vary greatly between sites :or. between surface versus oblique tows. Site 2 had the greatest number of species collected, a total of 19. for both tows, followed by Site 1 (18), Site 4,(17), and Site 3 (15). Site 4: wa's the only location where a significant. difference in: total species was obtained between the surface tow (16 species) and the' oblique tow (10 species). Site 4 had the greatest numbers of individuals,',collected with a total of 1J.903 -representing 45.3 % of the total for all four sites. Fish eggs and larvaO-. were most abundant at Site 1 where they comprised 2.9 % of the total plankton sampled. The predominent groups for the four surface -and oblique tows conducted during September 1983 included the invertebrate eggs (35.1% of the total)., copepods (26.1%) and shrimp and crabs (3.8%). These major groups are similar to results obtained in the previous plankton samples, except for the high percentage of fish larvae and eggs. Previously, this group normally comprised less than 1% of the total, with a high value of 2.9% at Site 1 during May. In the September samples, fish eggs and larvae ranged from a high of 32.9% (Site 1) to a low of 10.8% (Site 2), and reached 49.7% for a single tow at Site 1. 100 Comparison of results from other studies on plankton around Saipan and Guam indicate that, while overall densities are low in Bahia -Laulau, the predominant groups and relative abundances are quite consistent with seasonal variability. Only one other plankton survey has been conducted in the Bahia Laulau area (Birkeland et al, 1984 in press) Exact locations were not recorded but four tows were conducted in various parts of the bay.'. However, none were done in close to the reef. Predominant groups included invertebrate eggs, Calanoids, Chaetognaths, Eucheaia and shrimp and crab. larvae. Fish eggs and larvae varied from 0.*9% to 3.2% of the total plankton. This compares with results of the Laulau study except for the high values recorded in September (R 19.8%). The only other planktonic data from Saipan was done in Tanapag Harbor (Doty and@ Marsh, 1977). They obtained similar results in terms of. major groups of organisms but as is usually the case when @sampling in an enclosed lagoon or harbor, densities were higher. Relative. abundance: of fish eggs and larvae ranged from 0. 2% to 19%. On Guam, Amesbury (1978) sampled several locations along the west coast over a one year period. He found the highest densitids: of fish eggs and lar vae.occured in July and August (91.1% maximum) but.iwas as low as 2.7% at other times of the year. The sites with the '.greatest'. densities were enclosed bays or areas near extensive reef and/or mangrove areas such as Agana Bay, Agat, Bay and Ajayan Bay (near Cocos Island).': 'No sampling was done on the windward side of the island or offshore. Randall and Eldredge (1982) sampled plankton off Cabras Island*, Guam as-- part of an assessment for a potential OTEC facility. Although no sampling was done during the summer, they reported relative abundances of fish eggs and larvae ranging from less than 1% to a high of 43.5% (March). These ranges 101 are comparable to the results for Bahia Laulau and one would suspect that the site: at Cabras would be more similar to. Laulau than other locations sampled around Guam and Saipan. The Cabras study also reported high densities.:of Radiolarians, a group which is more commonly found offshore than in near-shore or lagoon environments. Species diversity in the September samples was quite consistent between sites, with 21 species at Sites 1, 2 and 3 and 18 species at Site. 4. Previous sampling generally showed the lowest diversity at Sites' 1 and 4@'.,* This' would be expected as:these two sites are closer to the points (eastern: boundaries) of Bahia Laulau and thus would likely contain fewer planktonic species than the sites@.that are closer to species-rich reef-flat areas of. the @Bay. CONCLUSIONS When all 'four plankton tows are analyzed togetheri Sites 1,: 3 and 4 had the lowest mean numbers of species with 12, 11 and 12 resoectively. Site 2 had the greatest species diversity with an. average of 181 species per tow. In terms'. '.o f total planktonic organisms per tow, Si te 4 @.averaged 1,506, followed'by'. Site 3 (1,201), Site 2 (867) and Site 1 (587). These results generally siApport what would be expected when looking 'at the current patterns and lack of a reef flat area along the-cliffs out to Puntan Hagman. Sites 2, 3 and 4 (particularly Sites 2 and 3) would be expected to be rich in plankton considering the current patterns, eddies, shallow areas and extensive reef areas present. In terms of gross impacts on the planktonic community, an OTEC plant would have the least negative impact in the area of Site 1 and would potentially affect Site 2 the most. The impact on planktonic species would be dependent upon the size of the mixing zone of the cold effluent, both in terms of temperature dif f erenti al (dilution) and the actual size 102 (3-dimensional) of the effluent plume from the discharge point. Both surface and subsurface currents would affect the size and shape of the mixing zone and it is likely that mixing and dilution would be more rapid and extend over a larger area at Site 1 due to the strong currents and submarine topography. 103 LITERATURE CITED Amesbury, S.S. 1978. Studies on the biology of the reef:fishes of Guam. Part II. Distribution of eggs and larve of fishes at selected sites on Guam. Coastal Zone Management Section, Bureau of Planning Gov. of Guam. 65p. Birkeland, C.@, S. A. Amesbury, R. R. Randall and A. ''Nelson. 1984. Assessment of inshore marine resources in the Ma'rianas: Archipelago. Sea Grant Project No. UG/R-4. Univ. of Guam Mar.'Lab.!:(in press). Doty, J. E. and J.A. Marsh, Jr. 1977. Marine survey of:Tanapag, Saipan: the power barge "Impedance". Univ. Of Guam Mar. Lab,., Tech. Rept. 31.' 147p. Randall,@ 'R.H. and L.G. Eldredge. 1982. Assessment of the shoalwater environment in the vicinity of the proposed OTEC development at Cabras Island, Guam. Prep. for Guam Energy" Office'. Univ. of Guam Mar... Lab., Tech. Rept. 79. 208p. Yamaguchi, M. 1972. Preliminary report on a plankto .n.,,survey in Palau, December 1971 to January 1972. 14p. 104 105 CORALS INTRODUCTION Reef-building scleractinian, octocorallian,, and hydroz.o.an corals are sessile invertebrates with potentially long life spans and distribution patterns that depend upon the particular environmental setting found, f r cm one habitat to another. Their stony calcium carbonate skeletons are major contributors to both in situ framework and detrital reef development in the shoal-water environments like that of Bahia Laulau. Characteristic cora@!' communities develop in response to the variable environmental conditions :found within an area, ranging from conditions completely unfavorable for,corals to optimum conditions. where corals are the dominant organisms in the community. Corals are sensitive to many environmental variables; particularly.. light intensity, suspended. materials in the water column, sediment accumulation on the substrate 'upon which they grow, water currents and agitation, seawater dilution from -surface drainage and groundwater d@scharg@ej temperature fluctuations@ emersion on shallow platforms during low tides, predation by other organ Iisms and various forms of pollution from toxic substances like thermal, storm drain and sewage discharges. Until recently, the coral community of Bahia Laulau had been evaluated from the point of view of degree of difficulty in landing military troops from the ocean (Cloud, 1959) and a generalized concept of where coral is found along the shoreline to the reef margin (Eldredge and Randall, 1980). Very little was done to identify species, community structure, zonation and distribution in these studies. Cloud (1959) did identify common named coral types in the vicinity of selected approaches to the beach. These were commonly referred to as 11staghorn or brain coral types." Gawel (1974) and 106 Gordon (1974) made preliminary surveys of corals in. the Saipan Lagoon on the west coast of Saipan but did no work in the Bahia Laulau area., Assessment of the present coral communities in Bahia Laulau will establish baseline data from which changes in the, quality of the reef environment can be determined or predicted. These data will be useful in establishing sound planning practices and management:of these reef areas in relation to future devel opment (OTEC or otherwise). The principal objectives of this part of the study are to determine the distribution and community structure of corals in Bahia Laulau from the shoreline to 10 m (33 ft) depth along four transect loc ations shown in Figure 13. METHODS The coral communities of Bahia Laulau were s tudied at, five sites. as shown in Figure 13. At each site, observations were primarily limited to a 20 m (66 ft) wide band that extended from the shoreline to a -depth of 10 m .(33 ft).:.@ High waves and rough surf conditions, that persisted for the duration, of the study period, prevented direct observations from-being made at the seaward edge of the fringing reef platform (reef' margin zcine) at Site .4. Strong bottom surge also prevented quantitative studies from being made on the submarine slope at Site 1 and on the forereef slope at Sites 3 an d 4. Where possible, coral communities were quantitatively analyzed within physiographic zones, discriminated at each site by using the poirit-centered or point-quarter technique of Cottam et al. (1953). Three physiographic zones consisting of the reef-flat platform, reef margin and forereef slope were discriminated at': Sites 2, 3 and 4. At Site la, the fringing, reef -flat platform an d reef margin zones were very similar physiographically and therefore lumped together. At Site 1 only the submarine slope zone was 107 distinguished since active reef development and a fringing reef-flat platform are absent. Sample areas were selected by, randomly tossing a hammer within the 20 m (66 ft) wide band of each, physiographic zone. At the intersection of the hammer handle and head a reference. 'point was established. Reference lines extended along the long axes of Ahe hammer handle and divided the sample area into four quadrants. Corals@ nearest the sample point (junction of hammer handle to head) in each. *quadrant were identified and the following data collected: diameter of 'the. colony (a maximum length and width measurement) and the distance from the colony center to the sample point. From this point-quarter data the following calculations were used to estimate community structure of the corals in each physiographic zone. unit area Total Density of all Species -to colony di stance) 2 (mean point Relative ',Density, individuals of a species X 100 total individuals of all species Total Percent Coverage total density of all species X average coverage value for all 'species Percent Coverage density of a species X 'average coverage value for the species Relative Percent Coverage percent coverage for a species X 100 total coverage for all.species Frequency number of points where a species occurs total number of points Importance Value relative frequency + relative density + relative percent coverage Density 'relative density of a species X total density of all species 100 108 Colony Size Distribution Data (n number of data', Y arithmetic mean, s = standard deviation, and w size range) were also calculated from point-quarter data. The coral species encountered during the point7quarter analysis indicate the predominant and common species within a zone. The presence of uncommon or rare species not encountered during the point-quarter analysis was determined by making 20 minute observations within a 20 m (66 ft) wide band in each zone. In zones not analyzed by using the point-quarter method, species lists were compiled by making- 20 minute observations within a 20 m (66 ft) wide band. An overall list of species is compiled for each zone within a site from both the point-quarter and dive data in Table 10 (Appendix A). Quantitative data from the point-quarter analysis are' presented in.: Table 11 (Appendix A). Vertical profile sections shown in Figure 4b indicate the zonation patterns discriminated, water depth, sediment distribution and the relative abundance of corals for each study site. RESULTS Description of Reefs and Coral Communities Zonation :'d from the Vertical profile sections (Figure 4b, Appendix B) that exten shoreline to 10 m (33 ft) depth indicate the general inshore* submarine topography and physiographic zonation patterns discriminated, w4'ter depth, sediment. distribution and relative abundance of corals at each, of the five study site s. Some reef zones have no corals at all, while other areas support communities ranging from a few widely scattered colonies'and species 2 and 3) to regions where the substrate is (reef-flat platform at Sites dominated by a relatively rich diversity of species (forereef slope zone at 109 Site 2) Although less noticeable, considerable community variation also occurs within the same zones from one site to another (Tables 10 and 11). Coral Distribution Ninety-eight species of corals representing 34 genera were recorded from the five study sites along the Lau'lau embayment,. (Table 10). Considerable variation occurred in species@ richness, size distribution, frequency of occurence, density and percentage of subst'rAe coverage between. the five sites and among the various zones discriminated at each site (Tables 10 and 11). DISCUSSION AND CONCLUSIONS One of the most noticeable. aspects of the coral communities stu*died at the five:.sites in Bahia Laulau is their unequal distribution from the inner reef -flat :platform to the 10 m (33 ft) depth contour- on the f6rereef slope. Much of the regional variation found in the community, structure of corals on the reef -flat platform zones is attributable to exposed platforms during low spring tides. Corals are unable to survive long periods of emergence, particularly when low spring tides coincide with extreme drying effects of the mid-day sun, and are thus restricted to parts of the reef-flat platforms that retain water during such times. Low tide exposure Iaccounts for lower species diversity, general low density and percentage of substrate coverage recorded for the reef-flat platforms zones at Sites 2 and 3. The few species of corals that were recorded on these periodically exposed platform zones were confined to small scattered holes which retain water during low tides. An exception to poor coral community development on the reef-flat platform zones was found at Site la (53 species recorded) where the reef platform zone remains completely submerged during low tides and at Site 4 (30 110. species recorded) where an extensive reef flat depression :creates a low-tide moat that retains up to a meter or more of water dur ing such times.. In contrast to poor coral community development. observed on the low-tide exposed reef-flat platforms at Sites 2 and. 3, species richness, density and substrate coverage increased dramatically where low-tide exposure is not a factor in the reef margin zones at Sites la and 2 (no reef margin development at Site 1) and at all sites in the: forereef slope zones (comparable to inner slope and submarine terrace zones at Site 1) Low density and substrate coverage values recorded in the -reef margin at Site 3 (Table 11) are thus a reflection of observations being restricted to the inner part where it grades into the exposed reef-flat platform zone. Substrate composition is another important factor that influences community structure and distribution of corals. Most corals require a hard rocky surf ace or a relatively stable unconsolidated substrate to settle upon and successfully grow. On the intertidal reef-flat platform zones. at Sites 2 and 3@ the relatively flat reef rock pavement 'surf ace areas are swept free of sediments by strong currents and storm waves.. The only deposits of sediment observed consisted of poorly s6rte*d mixture's of sand, gravel and rubble in some of the larger holes, troughs and depressions. At Sites la and 4 the subtidal reef-flat platform sediments werj@' similarly restricted, to* holes and depressions. Except for a few patches lof gravel, rubble and boulders lodged in the bottom of channels anal: fissures, sediments. on the wave-swept reef margin and upper forereef 'slope zones were absent. Sediment deposits observed on the coral-covered lower f shallow forereef slopes at Sit6s la, 3 and 4 were restricted to the floors 0 channels and troughs that funnel sediment downward to deeper forereef submarine terraces and slopes. The only significant sediment deposit observed was at Site 2 where a broad submarine terrace. interrupts the forereef :slope. Here extensive patches of sand, gravel, rubble:' and some boulders are found between coral-covered kno'bs, pinnacles, mounds and ridges. .:Although a few coral colonies are: found on relatively stable bouldersi most of the sediment covered areas. of the submarine. -terrace are unstable:and thus free of coral, growth. However, it -was....most' likely these small oases of coral growth on scattered boulders in the sediment covered areas of the terrace that were the forerunners of the. abunidant knobs and pinnacles of coral growth now found there. Although. considerable suspended sediment was observed, in the: water column,. both.. on the shallow reef platform, reef margin. and, forereef slope zones, it. di dnot appear to have much affect on the coral' communities or accumulate on the living coral tissues. Most likely this is because of strong currents 'and water agitation present during periods' of hormal Northeast Tradewinds',. Suspended sediment was particularly noticeable in the rich coral zon .es'. at - Site 2. Water transported onto the reef, platform by waves and swell: returns to the open sea via a shallow channel that. cuts across the reef-flat pl@a':tform and reef margin zones. Because of constant submergence and water circulation, normal annual and diurnal seawater temperature fluctuations that occur in ,the reef margin and forereef slope zones have little or no affect on the coral communities growing there. On the intertidal reef-flat platforms of Sites 2 and 3, and to some extent in the moat at Site 4, lethal or sublethal elevated temperatures may exist during low spring tides when water circulation is cut off and exposure to midday sunlight occurs. 112 Although some small streams discharge freshwater and some terrestrial sediment into the reef environment along the shoreline, it appeared to have little effect upon adjacent coral communities. Since Site 1 is indicated as the preferred location for the proposed OTEC plant a more detailed description of this region is given. Fringing reef development is absent along the w .ave-assaulted section of the coast at Site 1. As shown in the Site 1 profile (Figure. 4b) the inner part of the submarine slope is steep which at about@ 5 8 m (16 - 26 ft) depth grades outward into a more gentle downWard-sloping terrace. Bottom topography is irregular and humpy and cut here and there by large erosion channels and smaller grooves and fissures. The channel walls are steep to vertical, locally overhanging, scoured and undercut near the bottom. The channel floors show considerable evidence of scouring. and in most places along their length are strewn with large angular blocks, rounded boulders and patches of coarse sand and gravel. Although fringing reef development was not observed at this site, a moderately diverse coral community consisting. of 36. species (Table 10) was found growing on nonabraided surfaces of the steep inner slope, outer submarine terrace, mounds and upper walls of channels @.and fissures. Corals were also observed on the upper surfaces of large stable 'blocks and boulders, but were generally absent on smaller ones that are . apparently moved about by storm waves. Except for a few small stunted* colonies, corals were also absent on the floors of channels and fissures :and other locations where surface abrasion by loose sediments was.. evident. Percentage of surfacie coverage on nonscoured substrates at Site 1 was estimated to range from 10-30 percent. Predominant coral species include seven in the family Pocilloporidae, ten in the family Acroporidae and-nine in 113 the family Faviidae (Table 10). Corals from Site 1 that were.not. observed at other. sites in Bahia Laulau include Pocillopora ankeli, Scapophyllia: cylindric and Stylaster profundiporus. 114 LITERATURE CITED Cloud, P. E. , Jr. 1959. Geology of Saipan, Mariana Islands, Part 4, Submarine topography and shoalwater ecology.:: U.S. Geological Survey Professional Paper, 280-A. 126 p. Cottom, G. , J. T. Curtis and B. W. Hale.. 1953. Some sampling characteristics of a population of randomly@ dispersed individuals. Ecology 34:741-757. Eldredge, L. G. and R. H. Randall. 1980. Atlas. of reefs and beaches of Saipan, Tinian and Rota. Coastal Resources Management, Executive Office of the Governor. Commonwealth of the Northern Marianas Islands. 161p. Gawel, M. 1974. A preliminary coral survey of Saipan Lagoon. Univ.of Guam Mar. Lab. Environmental Survey Rept. 11. 13p. Gordon, G.D. 1974. A preliminary survey of the calcareou.s coralline algae of Saipan Lagoon. 9p. 115 MAC ROINVERTEB RATES INTRODUCTION Conspicuous macroinvertebrates were coll ected at four, coastal sites along Bahia Laulau on the east coast of Saipan, The only previous study in that area. was conducted between October 1948 and July 1949. (C@bud, 1959). Cloud described the shallow-water shore areas of Bahia Laulau 'as "intertidal to very shallow shore benches that are subject to nearly similar@',C'onditibns of heavy surf and to abrupt and extreme variations of temper,at ure 'and salinity" (P. 385). Cloud's Station 13a coincides quite nearly to Site of this study. He did not consider the parts of the reef seaward of the reef ..margin. METHODS@ e Specimens were collected from five stations during No'vemb'r 5, 6, and 7, 1982. -Specimens were collected during all reconnaissance scuba dives by all team members. Dr. Eldredge collected specimens i n the 'intertidal and reef flat@. areas. No quantitative data were attempted: fprI conspicuous macroinvertPb rates except for major forms like Acanthaster planci. To the east and protected from the rough water Site la allowed collecting on the narrow reef flat and in the block-and-boulder intertidal ,zone. Specimens were also collected here at a depth of .9 m (30 ft). At Site specimens were collected on the reef flat, reef front and at a depth of, .9 m (30 ft). Similarly at. Site 3, specimens were collected on the reef flat and at depths of 9 - 18 m (30 - 60 ft). Intertidal specimens were collected at Site 4, as well as from the reef flat and at depths of 12 - 15 m (40 - 50 ft). Specimens collected are listed in Table 12 ( Appendix A). 116 RESULTS Gastropods were the most commonly collected group totaling 88. species. Among these, 22 species belong the family Conidae,: ten to the Muricidae, nine to the Mitridae and seven to the Cypraeidae:. Only two species, Astraea rhodostoma and Vasum turbinellus were collected at all sites. Intertidal zonation is typical of that found in 'the southern Marianas. The pulmonate Melampus flavus represents the greatest abundance in the community. Another gastropod, Littorina coccinea is also a very high in Site 4. The abundance and occurred in especially large' numbers at remaining intertidal gastropods, Littorina undulata, Cellana radiata and N. plicata were found at Site 4 and at the low headlands. immediately south of Site 2. Of interest was the occurrence of the large'muricid Drupa morum on the seaward erosion platform at Site 4 and the cone Conus planorbis has.not yet been reported from Guam. Nine species of bivalves were collected. Voucheir specimens: of all the gastropods and bivalves have been deposited at the Dickinson Memorial Mollusk collection at the University Marine Laboratory. .DISCUSSION AND CONCLUSIONS Cloud (1959) reported ten gastropods from his Site 13a which included three cowries. One of his species names is an Indian Ocean :form and is unidentifiable. Of the six cone shells reported, one is also unidentifiable. All of the remaining forms and one vasid were also collected again during this study.. Although no specimens were observed during this study, the spiny lobster (Panularus @p.) and slipper lobster (Family Scyllariidae) are important resources of Bahia Laulau. Divers regularly harvest lobsters from the area, particularly at night. During appropriate tides and moon phases, harvesting also occurs along the extensive shallow reef-flats. 117 Twelve echinoderm species were observed during the study. They are large and readily identifiable forms. Healthy populations of Acanthaster planci were observed at all sites. The size of each @erd ( greater than 100 large individuals) was unexpected but prevalent th roughout Bahia Laulau particularly in the vicinity of coral-rich Sites 2 and.. 3. Some individuals represented the largest individuals (50 cm, 20 in) that have been recorded anywhere particularly in recent years. The significance of large populations of Acanthaster planci is evident from previous outbreaks in the Western and South Pacific regions. Reefs in Micronesia and Australia's Great Barrier Reef suffered extreme damage by Acanthaster between the late 1960's and mid 19701s. The history and early development of Acanthaster was studied by Cheney (1972) and. Tsuda (1971 and 1972). However, while these studies were going on teams @of divers were waging war on the huge populations that threatened to destroy coral reefs throughout the Pacific Basin (Chesher, 1969) and (Yamaguchi, 1971). Marsh and Tsud'a (1973), and Marsh et al (1971) surveyed the Mariana and Caroline Islands to determine the population levels of this particular coral killing animal. Randall (1973) provides the best account 'of a reiai prior to destruction by Acanthaster. By 1974 spawning and ch aracteristic aggregation of Acanthaster had been exhaustively studied (Cheney, 1974). However, it was not until Birkeland's 1982 paper.linking heavy rainfall after a dry period to increased populations that an understanding was, :gained into how such@ large populations seem to appear overnight in areas where none were. previously noticed. Two foraminiferid forms, Margonipora vertebralis and Baculogypsina sphaerulata were commonly seen in beach and reef flat sands. Both were previously reported by Cloud. (1959). 118 The reef flats at Sites 2 and 3 were more similar to one another than to those at. Sites la and 4 and all the intertidal zones were similar to each other. In summary, the conspicuous macr.oinvertebrates collected and observed: represent a typical reef flat and embayment area for :a southern Mariana island. With the inclusion of such large numbers of Aca:nthaster we can honestly. say that the area resembles similar bays and reef s:,'in' Micronesia in the late 1960's to mid 19701s. This find does not' :repres'ent a healthy short-term picture for the submarine ecology of Bahia Lau au. 119. LITERATURE CITED Birkeland, C. 1982. Terrestrial runoff as a .cause of outbreaks of Acanthaster planci (Echinodermata: Asteroidea). Mar. Biol. 69, 175-185. Cheney, D. P. 1972. Guam and the crown-of-thoi ms starfish: A short history. Guam Recorder 2(3): 74-80. 1974. Spawning and aggregation of:. Acanthaster planci in Micronesia. Proc. Sec. Int. Symp. Coral Reef s. Aust. Vol. 1: 591-594. Chesher, R. H. 1969. Divers wage war on killer star. Skin Diver Mag. 180): 34-35. 1969. Destruction of Pacific corals by the sea star Acanthaster planci. Science 165: 280-283. Clou& P.E. Jr. 1959. Geology of Saipan Mariana Islands. Part 4. Submarine topography and shoal-water ecology. . Geology Survey Prof. Paper. Marsh, J.A. Jr., R.T. Tsuda, M.R. Struck and F.A. Cushing. 1971. Acanthaster planci, crown-of-thorns starfish. Resurvey ':of Saipan, Tinian and Aguigan. 10p. Marsh, J.A. Jr. and R.T. Tsuda. 1973. Population levels of Acanthaster p I * in the Mariana and Caroline Islands, 1969-1972. Atoll Res. Bull. anci 1 - 16 . Randall, R. H. 1973. Reef physiography and distribution of corals at Tumon Bay, Guam before crown-of-thorns starfish, Acanthaster. planci (L.) predation. Micronesica 9 (1): 119-158. Tsuda, R.T. 1971. Status of Acanthaster planci and coral reefs in the Mariana Islands. June 1970 to May 1971. 127p. 1972. , Proceedings of the Univ. of Guam/Trust, Territory Acanthaster planci (crown -of -thorns starfish) whorkshop. 36p. Yamaguchi, M. 1971. Starfish control teams in Micronesia. Marine Parks Journl. 18:9-13. 120 .121 .............. ................ FISHES ............... ................. INTRODUCTION ................. Previous to this work no other assessment of fish resources in the .................. ............ . .... Bahia Laulau area had been done. Bahia Laulau is a unique and valuable ................. asset to Saipan's recreational and subsistence fishery. This large windward .................. bay contains a wide range of habitats which have the potential to, date many important species of fish. Despite this, and the bayls: ............... accommo .................. .................. reputation of being a good diving and fishing:spot, very little is known of .................. ................. the fishes that live there. The objectives of this study were to investigate. ........... the species composition, distribution and general density of the fishes seen" ................... ................... ................... on the reef flat and shallow forereef slope. The data presented here- provide baseline information an Bahia Laulau that will be useful in -assessing ............ .............. its reef community as a whole and in gaining a better understanding of its ................... reef fishery potential. METHODS ... .......... The conspicuous shallow-water fish fauna of. Bahia Laulau was surveyed ................ between November 3-7, 1982. Reef flat reconnaissance was done with mask .................... .......... and snorkel and SCUBA was used to survey the forereef slope. Species. .................... . .................. checklists were compiled at five study Sites (1, la, 2,' :3 and 4). Line transect counts of fishes were made on the reef flat and :forereef slope at ..................... ............ ............. Sites 2 and 3. Fishes observed along these transects were' counted only- if ..................... they were within 1 m (3 ft) of either side of the line and less than 2 m .................... .................. .......... above it. .... ......... .................... ...................... Rough ocean conditions at Sites 1 and 4 limited the -investigation to single 45-minute reconnaissance dives on the forereef slope. Site 1 fishes ...................... .................. ..................... ........... ........... ..................... 122 were observed to approximately 21 m (70 ft) and Site 4 species were surveyed down to 18 m (60 ft). Greater time was spent at -Sites 2 and 3 since they were.more protected and contained accessible reef flats. Care was taken to sample: fishes in both the shallow and depressed areas of the:reef flat. At Site 2, fishes were surveyed during a 45-minute swim and counted. along, a 50* m (164 ft) transect line placed within a depressed area'near an: old pipi@line. Site 3 fishes were counted along a 100 m (328 ft). transect. line that traversed mostly along shallow pavement. Together, these tran,@'ects covered eight 10 m (33 ft). sections of depressed reef flat and seven 10- ri@ :03 ft) sections of shallow pavement. On the forereef slope at Sites 2 and 3, :reconnaissance as well as 100 m (328 ft) transect counts of fishes were made at 9 and:18 'm-. (30: and 60 ft. q. a These transects traversed substrate that was uniformly c*oVered with coral and algae-7covered rocks at both depths at Site 3. At Site:'2,' however, the transects' e:xtended across substrate that varied from-exte nsive sand/rubble areas conta-Ining isolated rocks and coral heads to area:s.-d-Imost completely covered by: coral. Fish densities calculated from the transect data were converted to a standardized form to reflect densities per. JO m (66 ft) of transect line or 20 m 2 (215 ft2 of substrate. RESULTS Species Diversity Table 13 (Appendix A) lists the fish species seen at the four study sites. Altogether, 200 species belonging to 35 families were recorded. The most well represented families included the Labridae (33 spp), Pomacentridae (23 spp), Acanthuridae (19 spp), Chaetodontidae (17 spp) and Scaridae (13 spp). These five families contributed 52 percent of the total number of 123. observed species, while the Labrids alone accounted for 16 percent of the total. Although the ocean surface at Site 1 was rough,:below 10 m (33 ft) the surge diminished rapidly and visibility was fairly. good. A total of 107 species representing 23 families were observed. Approximately 10 percent of the total number of species recorded at all sites We*re seen exclusively at this location. Recon.naissance at Site 4 was more difficult and less fruitful. Not only was the surface very rough, but there were also a strong surge and much reduced visibility down to 18 m* (60 ft). Only 73 species comprising 19 families were observed. Only two percent (4) of the total recorded species were observed exclusively at this site. Not surprisingly, the greatest numbers of species were, recorded at Sites 2 and 3@ At Site 2, a total of 130 species belonging to 31 families were seen on the reef flat and forereef slope. Approximately 12 percent (34) of the total recorded species were observed solely at this site.. A slightly lesser number of species were observed at Site 3 where 125 spe cies repre- senting 28 families were recorded. Approximately 10 percent (.21) of the total recorded species were seen exclusively at this site'. The combined reef flat data for Sites 2 and 3 yielded a total of 42 species representing 23 families. These species are listed in Table 14 (Appendix A) . Juvenile Fishes The presence of juvenile fishes was recorded during, :both the reconnaissance and transect dives. These species are listed in Table 15. Based on the abundance of the smallest individuals, none of the se species showed evidence of recent large-scale recruitment. Within both the. reef flat and forereef slope zones the largest numbers of observed juveniles belonged to the family Pomacentridae. Juveniles belonging to the familes Labridae and 124 Acanthuridae were also among the most numerous. In all, juveniles were recorded.among 31 species within 9 famlies. More than half of these species are herbivorous. Food Fishes At least 38 percent (75) of the recorded species are: known to be desirable food fishes. These species have potentially important.'economic and recreational value and are identified in Table 13 by an asteriski. A bout 33 percent (35) of the Site 1 species are listed. a s a-esirable food 'fai fishes. The, majority of these species belong to the milies @.Acanthuridae (34%), Lutjanidae (11%), Mullidae (11%) and Scaridae (11%). Some :of the more important species seen at mid-depth were the emperor, Lethrinus semicinctus (Mafute); several surgeonfish species -of the genus Naso, includin& Naso unicornis (Tataga); and the rabbitfish, siganus argenteus (Hiting).:.' The largest individual food fishes seen during,,the entire study were recorded at Site 1 near the 21 m (70 ft) depth. These included the snappers,::, Aprion virescens, Lutjanus bohar (Tagafi),, Lutjanus rivulatus, Lutj anus 'iusselli; and the groupers, Plectropomus JeoParous (Godao) and Variola lou'ti. At Site 4 only 27 food species were recorded, yet these made up 37 percent of the total number of species seen there. The.. major food fish f amilies included the Acanthuridae (37%), Scaridae (18%), Labridae (15%) and Lethrinidae (11%). Among the most important food species were Lethrinus semicinctus (Mafute) and Siganus argenteus (Hiting); the emperor, Lethrinus harak (Mafute); the snapper, Macolor niger; the surgeonfishes, Naso hexacanthus (Gausa) and Naso lituratus (Hangun); the goatfish, Parupeneus bifasciatus (Salmoniti); and several parrotfish species, including Scarus rubroviolaceus (Lagua). 125 Desirable food fishes composed 39% (51) of the Site 2 1species, and were most represented by the Acanthuridae (22%), Scaridae (16%), Mullidae (14%) and Holocentridae (12%). The most abundant food species seen on the reef flat were small schools of the surgeonfish, Acanthurus triostegus (Kechu); the goatfish, Mulloides flavolineatus (Tiao); and the rabbitfish, Siganus spinus (Seyun). Other important reef flat species included Lethrinus harak (Mafute); the jack, Caranx melampygus (Tarakito); and the snapper, Lutja'nus fulvus (Kakaka). The principal food species observed on the forereef slope consisted of Lethrinus harak- (Mafute) and Mulloidichthys flavolineatus (Tiao) several surgeonfishes, including Naso lituratus (Hangun); the squirrelfishes, Adioryx cau@limaculatus (Suksuk), Adioryx spinnifer (Sesiok), Myrpristis berndti (Sagsag) and Myrpristis murdjan' 7- (Sagsag); the jack, Caranx sexfasciatus (Mamulon); several wrasses, including Cheilinus undulatus (Tanguisun); the grouper, Epinephelus merra (Gadao); the sweetlips, Plectorhynchus orientalis (Hamala); and several parrotfishes, including Cetoscarus bicolor and Scarus, gibbus (Lagua), both of which attain relatively large sizes. Nearly 31 percent (38) of the Site 3 species are considered desirable food fishes. The prominent food fish families were the Acanthuridae (26%), Scaridae (15%), Lutjanidae (13%), Holocentridae (10%) and Labtidae (10%). The major food species recorded on the reef flat included. Acanthurus triostegus (Kechu), Mulloidichthys flavolineatus (Tiao) and Siginus spinus (Seyun). Other important reef flat food species were Adior y x spinnifer (Sesiok) and the grouper, Cephalopholis sonneratus (Gadao).. On the forereef slope, the important food species included the following: Lethrinus harak (Mafute); Lutjanus, bohar (Tagafi), Lutjanus fulvus (Kakaka) and Macolor niger; Adioryx spinnifer (Sesiok), Myrpristis berndti (Sagsag) and 126 Myrpristis murdian (Sagsag); several surgeonfishes, including INNaso lopezi, Naso hexacanthus (Guasa) and Naso lituratuis (Hangun); the: snapper, Aphareus furcatus and several parrotfishes, including Scarus gibbus (Lagua)..:@ Fish Density 'transects at Fish density at Bahia Laulau was investigated along jine Sites 2 and 3. Density values calculated from these data are' presented in Table 16 (A:Pendix A). The reef flat breakdown b' site @'shows similar p y f individuals densities of species between sites, but a much higher -density 0 occurring. at Site 2. However, the latter is misleading and is probably largely the result of transect placement rather than to significant differences between sites (see Methods). A better way to use these, data would be to compare fish densities between the shallow pavement and depressed areas of the reef flat (Table 17, Appendix A). These values do 'indicate real difference s@: and help explain why the density of individuals ':at, Site 2 was so high. Fish dl'pnsities calculated for the forereef slope are broke.n;down by site and depth iii Table 16. Overall, the density on the fo rer eef 'slope was about twice that found on the reef flat. Within each study, site@ similar densities were found at both depths. However, quite different densities were found between study sites. The fish density at Site 3 was consistently higher. At 9 m (30 ft), a. 36 percent greater species density, as well as a 52 percent greater density of individuals were found. At 18 m (60 ft), Site 3 showed a 57 percent greater species density and a 41 percent greater density of individuals. As in the case of the reef flat, substrate variability appears to be related to the density differences observed on the forereef slope (see Methods). It is evident from Table 17 that fish density at Site 2 increases 127 with substrate complexity at both depths. It is also. interesting to note the high degree of similarity between the densities at Site 3 and those. over the coral-covered areas at Site 2. DISCUSSION Considering the limitations imposed on this investigation by time and nature, Bahia Laulau was found to contain a fairly diverse shallow-water fish f aun a. In general, the fish communities observed a.t each study site ap- peared to be healthy. The numbers of species that were found to be unique to a single study site were relatively low,* ranging from 2-16 percent (x = 10%) of the total recorded species. This is an indication of widespread recruitment of species within the bay. More extensive reconnaissance throughout the bay, especially at depths greater than 18 M (60 ft), and within the vicinities of Sites 1 and 4, would undoubtedly reveal the presence Of several other important species. A thorough survey of the more cryptic, burrowing, nocturnal and pelagic species would also increase the overall species list significantly. Furthermore, the overall abundance of shallow-water coral reef fish is known to fluctuate seasonally largely as a result of reproductive activities. In the Mariana Islands, peak fish abundance occurs from April through July. Several studies support the belief that coral reef fishes increase in abundance in the spring and early summer months due to both spawning peaks and increases. in recruitment (see Johannes, 1978 and 1979; Kock, 1982 and Molina, 1982). Had the same survey techniques been employed during the -peak season, it is likely that a greater number o.f species as well as juveniles, would have:.been encountered. In addition, the ratio of carnivores to herbivores among juveniles may also shift seasonally with the former being more abundant during the late spring and early summer months. 128 The percent of desirable food species seen during th e survey was fairly uniform across study sites. These species ranged from 31-39 :Percent of the total number of species recorded at each site. These figures should be regarded.:as minimums when viewed in relation to the bay's fishery potential. In addition, better diving conditions and more extensive reconnaissance would have resulted in the identification of other importan`t;.'@ood fishes, especially among the more secretive and deeper' living species. The bay does have a significant reef fishery potential: for', variety of (teki fishing methods'. The reef flats offer cast net (talaya), gill n e't! n) and limited surround net (chinchulun umesugan) possibilities A more diverse array of:.species are taken with the latter two methods since their catch is limited primarily by the location and mesh size of the net., Species commonly caught :by. gill and surround nets include many wrasses, snappers, emper- ors, jacks, parrotfishes, rabbitfishes, surgeonfishes, and' goat.fishes. Cast netting, on the other hand, is a selective method usually: used to target in on specif ic species such as Acanthurus triostegus, :.(Kechu), Caranx melampygus: ! (Ee), Mulloidichthys flavolineatus (TiaoYt@ .',Naso unicornis (Tataga) and Siganus spinus (Seyun). Angling with hook and line is another method commonly.. employed on the reef flat. This method may also be selective when used alo h g the shore to catch schooling juvenile jacks such as Caranx melampygus (Ee) and Caranx sexfasciatus (Mamulon), or from the reef margin to catch fishes over the reef front, such as Naso unicornis (Tataga). Much of the selectivity of this method is determined by the reef zone or depth that is fished and by the type of bait and tackle that is used. Over the forereef slope, deeper dwelling species such as the larger snappers, emperors, wrasses, jacks, sweetlips and squirrelfishes may be caught with hook and line from a boat. 129, Spearfishing is another selective method that has a. high potential on the forereef slope. Species that are highly desirable by spearfishers. include; Adioryx spinnifer (Sesiok), Caranx melampygus .:(Tarakito), Cheilinus undulatus (Tanguisun), Naso unicornis (Tataga), and the larger snappers, emperors, sweetlips and parrotfishes. Local fishermen consider that the fish populations -close to the reef flats have declined as a result of the pressure from heavy fishing in recent years'. However, fishing in the bay as a whole is' still considered to be excellent. Other important species seen within the bay include four species of Caesionidae (fusiliers). These relatively unexploited s pecies. have potential as food and as baitfish for tuna. Unfortunately, their abundance was not observed to be high, but this may be because they. are only indirectly associated with the reef. Relatively few of the reef fishes traditionally regarded as dangerous to humans were seen during this survey. Those observed included a large adult stingray (Taeniura melanospilos) (Hafula) seen at 9-m .(30 ft) at Site 3, a young black-tip shark (Charcharhinus melanopterus) (Haluu) and a moray eel (Lycodontis sp.) (Titugi) recorded on the reef flats at@ Sites 2 and 3 respectively. The transect data yielded calculated fish densities that may, be used to partly characterize the reef flat and forereef slope fish communities. Dif- ferences in.the fish densities within each of these zones appear to be related to differences in substrate complexity. More complex substrates have a greater potential for a 'ccommodating larger numbers of species and individuals per area than less complex substrates. This was well illustrate d on the forereef slope at Site 2, partially explaining why the densities at Sites 2 and 130 re may be useful in 3 were so different The density values presented he obtaining. gross estimates of the demersal fish 'resources existing within the bay down to 18 m (60 ft). CONCLUSIONS The. fish community in Bahia Laulau down to .21 m .(70 Ift') is fairly diverse and appears to be in a relatively healthy statei This, ;@hd the wide range of habitats found there, makes it a location potentially'@ valuable for ecological studies of reef fish. Many important species of f oo' 8fishes are present. and the potential for recreational and subsistence fishing is also high. The replenishment of harvested food species should riot 'be a problem since the: bay is large and inaccessible to fishing by,rough seas, during most of the year. The more remote regions of the bay should be excellent sources. of. new recruits for the more heavily fished areas. Alth6ugh Bahia Laulau represents a significant recreational subsistence fishery for: th' island, preliminary data provides no basis f or: the support of an inte .nsive commercial fishery here. However, based on :observations made during this:.study, we feel that the resources contained within.the bay could support a @Iimited commercial fishery for reef fishes. In "this regard, spearfishing and, shallow-water hook and line fishing have the greatest potential. There may be some species of fish that are not being utilized from Bahia,'Laulau at the present time. These may represent an excellent, though perhaps seasonal, resource (pelagic types, ie. tuna and mahi-mahi). In any event, the@reef and reef associated fishery resources should continue to be utilized for recreational and subsistence fishing until more data are available to support demands for additional fishery development. 131, LITERATURE CITED Johannes, R.E. 1978. Reproductive strategies of coastal marine fishes in the tropics. Envir. Biol. Fish. VoIIII, p.65-84. 1979. Improving shallow water fisheries in the Mariana Islands. Unpubl. Report. 23p. Kock*, R.L. 1982. Patterns of abundance variation.in reef fishes near an artificial reef at Guam. Environ, Biol. Fish., V61VII, No.2, p121-136. Molina, M.E. 1982. Reef fish population inve@;tigations through the use of permanent transects. In annual report, Dept. :of Agriculture, Aquatic and Wildlife Resources Div., Guam, R.D. Anderson, M.E. Molina and A.J. Hosmer Editors. p88-128. 132 133 MARINE TURTLES AND MAMMALS INTRODUCTION Both the green sea turtle (Chelonia mydas) and the hawksbill turtle (Eretmochelys imbricata) are known to occur in the waters of Bahia Laulau. Interviews with local fishermen and divers, as well as sightings by team members during this study indicate that the green sea turtle is a frequent inhabitant of the bay, while the endangered hawksbill turtle is more seldomly seen. According to information from Ben Concepcion, a local diver and fisherman, no noticeable decline in the turtle population in Bahia Laulau is evident. He normally sees one or two green turtles on. every dive he makes, spotting them either underwater or on the surface from a boat. He says' that "turtles are more numerous around the points, such as Hagman and Dandan and in the waters surrounding Forbidden Island." Marine mammals, particularly porpoise, are known to occur in Bahia Laulau (Tersonal observations of Ben Concepcion). However, no record of @sightings or other scientific works verify these sitings. Porpoise of an unknown variety were observed moving through the bay on two field visits (February and May 1983) during this study. It is expected that porpoise venture into Bahia Laulau for feeding and protection during' migration. There did not appear to be a resident popul.Ation of porpoise in.Bahia Laulau while our survey was going on. There is no known record of whale sitings in Bahia. Laulau and none were observed during this study- METHODS Prior to each field visit all research participants were instructed to look for marine turtles and mammals while on their respective surveys. Separate transects or observations were not run since we did not expect to observe 134 great numbers of these animals. Instead, we made a point to. keep an eye :ithei by boat, out for these animals wherever a research participant went. e car or while diving. Observations were made by boat, underwater by scuba and skin diving and from observation points high above the bay. In addition, knowledgeable locals were surveyed regarding their personal observations recently and over the past few years. RESULTS Turtles'were spotted at different locations throughout Bahia Laulau on each of the four field surveys. Sightings were made from' obser.vation- points above Hagman Point (Site 1), Chamorro, Village' (Site. and':the Quarry (Site 4). Turtles' were also sighted while working underwater:.at' all sites. A total of ::9 turtles were observed during the study. More turtles were observed:@ on the surface at Sites 1 and 4 than at the other sites either on the surface or underwater. Two green sea turtles (Chelonia mydas) and one hawksbill' Eretmochelys imbricata) were observed floating qn:'the surface from our observation post above Site 1. Three green.' sea. -turtles (Chelonia er 'b mydas) wi e observed floating off Site 4 from our quarry p, servation post. One each ',of the green and hawksbill turtles were observed underwater at Site 2 and, one Hawksbill at Site 3. Turtle nesting has been observed along the beaches which occur within Bahia Laulau. Information from Mr. Concepcion and a few residents in the area revealed that they have observed green turtle nests at beaches below the airport and quarry site in southern Bahia Laulau (Site 4 of our survey). Recently Mr. Concepcion observed a few nests at Dandan Beach. Ben Sablan, Fisheries specialist at the Division of Fish and Wildlife, recorded two nests at Puntan Hagman during 1982. He reports that in the mid-1970's, 135 scuba divers were harvesting turtles regularly at Naftan' Point, Forbidden Island and the Grotto. DISCUSSION AND CONCLUSIONS Because of the rather extensive development of the shoreline and beach areas along the west coast of Saipan, there is a shortage of protected nesting areas for turtles. Even some of the nesting sites on the east coast are visited frequently by fishermen and tourists. Disturbing and robbing eggs* from these nests has seriously affected the reproductive efforts of the turtles. This situation makes the few relatively inaccessible. nesting beaches in Bahia Laulau very important for the continued survival a nd conservation of these animals. Nesting sites need to be better protected during the nesting season (March-July) and laws protecting the turtle nests need to be enforced. At the present time, all marine turtles are considered to be either threatened or endangered in the CNMI. Continued education is essential to enlighten the public as to the steps necessary in protecting and': conserving this precious biological resource. Although both the green and hawksbill turtles are protected by the Federal Endangered Species Act, CNMI residents are exempted from the provisions of this act and allowed to take green turtles for subsistence purposes only. Subsistence taking is defined as "customary,': traditional taking of restricted game to provide sustenance for the taker and his or her immediate family when no other means of providing sustenance is. .available or when curtailment would result in severe malnutrition." Only one green turtle may be taken per season (September 1-November 30) and,,only CNMI- citizens may take a turtle after purchasing a $5.00 license. However, the CNMI government may pass more stringent laws or regulations in regards to the taking of endangered species. To this end the Director of Natural Resources may grant exemptions from limits for subsistence taking of wildlife. @136 Additional regulations state that green turtles les's than 34 inches in length measured across the top of the carapace may not, be taken, taking of green turtles inshore of the mean low tide mark: is prohibited, no person shall disturb or take eggs from a nest, green turtles may. not be trans- ferred, sold or exported and the taking of green turtles must be customary and traditional. 137 OTEC DEVELOPMENT INTROD :UCTION The CNMI government recognizes the Amportance of OTEG development as a part of its renewable energy program in- order to reduc*e''ifs dependence on imported fossil fuels. In their OTEC. pilot plant program technical proposal the CNMI concluded that 11OTEC is.,one of its, few'*, 'alternatives as a 'tal-in'tensive baseload electric power source. OTEC @represents :.4. capi approach to the production of electric power. Although. the fuel is free and renewable, the high initial capital costs plus . 'Ahe lack of sufficient demonstration of the technology and economics on a large.@'scale have been a barrier !to the rapid commercialization of OTEC. Four small OTEC applications represent the bulk of technological advancement in the field: Mini-OTEC, OTEC-1, Seacoasf:'Test Facility and the Nauru plant. In July 1979 the Mini-OTEC. plant was deployed off Keahole the island of Hawaii and became the woitld's. first successful Point on'. closed-cy ,@,je OTEC plant producing an average of 18 kW net electricity during its 620 hours of operation. OTEC-1 is a. converted T-2 tanker renamed Ocean Energy Converter and was deployed, off'.@ Keahole Point in September: 1980. The Seacoast Test Facility is a land-based OTEC plant from which biofouling and corrosion experiments are being conducted. The 100kW Nauru OTEC plant was placed in operation in October of 1981 and a continuous operation test was carried out for ten days in November 1981. This test proved the reliability and performance of the plant under continuous operation and valuable data applicable to future commercial OTEC plants was obtained. Due to successful completion of the 100 kW Nauru pilot 138 plant the developers are now willing to undertake construction of a 2,5OOkW commercial plant. Significant potential for OTEC application exists in tropical and subtropical zones between 200 S and 200 N latitude. where delta T exceeds 200C. Figure 17 illustrates this resource in terms of the average of monthly temperature differential. A comprehensive list of 98: p*otential OTEC nations and -territories has been developed from basic OTEC- criteria (Table 18). These criteria are based on significant monthly delta T within 370 kilometers (200 miles) from shore, also known as the Extlusive Economic Zone (EEZ). These nations and territories can be categorized as follows. 1. Developed nations - 3 (U.S., Japan, Australia). .2. Territories of developed nations 29 (U.S.9 Japan, France, UK 9 Netherlands and NZ). 3.. Developing nations with free-market economies 63. Perhaps the greatest OTEC potential is in developing nations and territories. Table 19 illustrates the key oceanographic resource parameters for 67 of these nations and territories (excluding territories of developed nations except Guam, Trust Territory of the Pacifici Virgin :1slands and American Samoa and the centrally planned economic :nations).- These 67 nations and territories combined have a projected installed electrical capacity of approximately 284,000 MW in 1990 and a potential 1 460, 000 MW by the year 2010. Much of.this could be supplied by OTEC. The Saipan location and Bahia Laulau site represents one of the best OTEC resources in the world with the average of monthly temperature difference between th'e warm surface and cold deep ocean waters exceeding 210C. There are two estimates of the thermal resource available in the Marianas; Lassuy (1979) University of Guam and Dames and Moore (1979) in 139 AT('C) BETWEEN SURFACE AND 1.000 METER DEPTH 16", 15OW I AVw 13OW I?aw llow IDOW 90w SOW 7OW SOW: saw 4" 3vw zow, low Ow 10C ?Of 40": ................ am .................. ..................... ....... ... ............................ ......... . . ........... ........... .......... ....... ....... ......... 30M ir zr 16 ng 21 IVA low E0 Ea zr las ....... ... ........ .... .. . it, ................ ..... ....... ................. ....... ...... 30S .. ................. 30S .......... ............. . ............. ........................ ................................................. . .............. .................. .................... ................... ............... . 40S 1. 63w1 14OW 13OW T2vw Ilow ?Dow POW Dow 7vw SOW sow AVW 3DW "W IVW DIN ICE "t AT(C) BETWEEN SURFACE AND 1000 METER DEM 40M 7VE ME WE lom IIOE 12DE 130E 74DE II50E nOE' 'inE ISOE 17vw 16OW ISM ............... - ...................... 1... 404 4L ..................... - ................... :::::I ................ . . ........... .. ........................ 30( 1 .......... 30" Z7 21' .... . ..... .. ION ION ....... SATP .. .. ...... las 24, In ........ . . A Ir ?r .... ..... ........... ..... ............ if . . ............. . ... .......... ............... 36DS ......... ........ ....... XI X .............. 4M --- . . ....... ............ .. .... ICE wx xx lam l1w ME lux lux IN* INK VIVE Iwx IM ISO* Ism C= r. LIU W.Tw' r: E=3 P, @ , r. = -@w 0 -Mv @. ue.fj. M W.". ffy" Liss "",ON WTI= Figure 17, Potential OTEC Thermal Resource. 140 Table 18-. Nations and Territories with Thermal: Resource (Mean) Annual AT >20% @1000 M Depth within 200 nm EEZ) GEOGRAPHICAL AREA MAINLAND ISLAND LATIN MEXICO GUYANA CUBA GUADALOUPE (FR). AMERICA, BRAZIL SURINAM HAITI MARTINIQUE (FR) COLOMBIA FRENCII GUIANA(Fr) DOMINICAN REP. BARBADOS COSTA RICA NICARAGUA JAMAICA DOMINICA GUATEMALA EL SALVADOR VIRGIN IS. (US) ST. LUCIA HONDURAS BELIZE (UK) GRENADA ST. KITTS (UK) PANAMA UNITED STATES ST. VINCENT BARBUDA (UK) VENEZUELA GRAND CAYMAN (UK) MONTSERRAT (UK) ANTIGUA (UK) THE-GRENADINES (UK) PUERTO RICO (US) CURACAO (NETH) TRINIDAD AND TOBAGO ARUBA (NETH) BAHAMAS AFRICA NIGERIA GABON SAO TOME AND PRINCIPE GHANA BENIN ASCENSION (UK) IVORY COAST ZAIRE COMOROS KENYA ANGOLA ALDABRA (UK) TANZANIA CAMEROON MADAGASCAR CONGO MOZAMBIQUE GUINEA EQ. GUINEA SIERRA LEONE TOGO LIBERIA SOMALIA INDIAN/PACIFIC INDIA AUSTRALIA INDONESIA AMERICAN SAMOA (US) OCEAN BURMA JAPAN PHILIPPINES TRUST TERRITORIES (US) CHINA THAILAND SRI LANKA GUAM'(US) VIETNAM HONG KONG (UK) PAPUA NEW GUINEA KIRIBATI BANGLADESH BRUNEI (UK) TAIWAN FRENCH POLYNESIA (FRANCE) MALAYSIA FIJI NEW CALEDONIA (FRANCE) NAURU DIEGO GARCIA (UK) SEYCHELLES TUVALU MALDIVES WAKE-IS. (US) NEW HEBRIDES (UK/FR) SOLOMON ISLANDS SAMOA MAURITIUS TONGA OKINAWA (JAPAN) COOK IS. (NZ) WALLI$ A FUTUNA IS. (FR) TOTALS: 44 54 141 Table 19 Oceanographic Resource Parameters Thermal. Thermal Usw Res@ource Frequency Geojraphical Resource Proximity. Size' of Severe Currents Area@---- Nation (00 (km)' (km), S torm@ m 300 Indtan/Pacific Indonesia '56 660@ 22-23 10- 0 AD 0-0.1 0.2-0.4 Ocean Papua New Guinea 23-24 <10 >1000 0.1-0.5 0.4-0.6 Kiribati >24 <10 @250-500 0-0.1 0.4-0.6 Tuvalu >24 <10 0-0.1 0.2-0.4 Solomon Islands 23-24 <10 '.500-1000 0.1-0.6 0.4-0.6 Nauru >24 <10 04. 1 0.4-0.6 Trust. Terr. Pacific >24 <10 .600-1000 1.0-3.0 0.2-0;4 American Samoa 23-24 <10 :100-250 0.1-0.5 0.1-o.2 Samoa Z3-Z4 <10 A00-250 0.1-0.5 0.1-0.2. Philippinas >24 <10, >]boo >3.0 0.2-0.4 Tonga 20-21 <10. 100-250 0.1-0.5 0.1-6.2 India 21-22 50-100 >1000. 1.0-3.0 0.2-0 4 Guam >24 <10@ 100-250 1.0-3.0 0.2-0:4 Fiji 21-22 10-50 250-500 0.1-0.5 0.1-0.2 Sri Lanka 21-22 10-50 506-1600 0. 5-1, 0 0.6-0.9, Maldives 21-2Z <10 500'-1000 0-0.1 0.4-0.6 Ma uri ti us 20-21 <10 1.0-3.0 0.1-0.2 SeychelTes 21-22 10-50 250-500 0-0.1 0.4-0.6 Taiwan 21-22 10-50 250-500 >3.0 0.4-0.6 Durma 2)-22 10-50 100-250 0.5-1.0 0.2-0.4 Malaysia 23-24 100-370 100-250 0.5-1.0 0.2-0.4 Bangladesh 21-22 1 200-370 <100 @ 1.0-3.0 0.2-0..4 Africa Liberia 22-23 10-50 250-500 O-OA 0.6-0.9 Ivory Coast 22-23 10-50 250-500 0-0.1 0.6-0.9 Ghana 22-23 10-50 250-500 0-0.1 0.6-0.9 Nigeria 22-23 50-106 - 250-500 0-0.1 0.6-0.9 Togo 22-23 10-50 <1do 0-0.1 0.6-0.9 Renin 22-23 10-50 <100 0-0.1 0.6-0 ' 9 72-23 50 - 100 100-250 0-0.1 0.6-0.9 Gablin 21-22 50-100 250-500 0-0.1 0.6-0.9 Mozambique 20 - 2 1 10-50 500-1000 0.5-1.0 0.6-0.9 Sao Tome h Principe 22-23 10-50 <100 0-0.1 0.6-0.9 Eq. Guinea 22-23 10-50 <100 0-0.1 0.5-0.9 flumber per 5' Latitude Longitude Square 142. their preliminary EIS for a Guam OTEC. The consensu's of these data conclude that a year round temperature differential over 210 C (69.80 F) exists at a depth of 550 m (1,800 ft) and a 230 C (73.40 F) differential can be obtained at a depth of 900 m (2,952 ft). Siting of OTEC plants must consider existing competing ocean uses to avoid conflicts that could delay approval by local and federal agencies. Extensive U.S. offshore oil activities, with a large n umber of existing plat- forms, pipelines, operations of drilling and logistics vessels do not exist in the regions of most Pacific Islands. In contra.@3t to the coastal areas of the U.S. continent and, to a reduced degree, of Hawaii and Puerto Rico, there Therefore, are only a few ocean uses in the vicinity of the Pacific, Islands. the potential for conflict with existing competing ocean uses is. considerably reduced for the small Pacific Island OTEC pilot plant program.: The competing ocean uses on which OTEC facilities may be expected to impact in the Commonwealth of the Northern Marianas are fisheries, navigation and possible deepwater port development. However, the location of any OTEC facility can be planned to cause the minimum of interference with shipping and port development. The only ocean use: that could realistically be affected in the foreseeable future is that @of fisheries. At present, the fisheries of the Northern Marianas are largely of the subsistence variety with some recreational fishing and a small local commercial industry., Nevertheless, there is a high potential for development of a commercial fishing industry as has been shown by the successful efforts achieved by the Japanese, Taiwanese, Korean and more recently I arge U. S. purse seiners in Marianas waters. The development of a viable commercial fishing industry is of central importance to CNMI economic independence and self-sufficiency and is recognized as such in the recent Draft Fisheries 143 Development Plan, FY 1981-85. The recently enacted Marine Sovereignty Act Northern Mariana of 1980 stresses the dependence of the people of the Islands on the resources of the sea "for their economic, social and political survival.:and growth" and the consequent need to establish 6 ntrol over marine resource exploitation. The Act inter alia establishes a.3.70 kilometer (200 mile) economic zone for this purpose. The effect of an OTEC facility on fisheries relates to the :displacement of warm, shallow water with cold, deep water and theresulting' modification of temperature, salinity, density, dissolved oxygen, nutrients:, carbonates and particulates. This "artificial upwelling" caused by an .:OTEC operation can result in an increased fish population and therefore higher yields. However,, the overall impact of a small OTEC plant is likely to b e minimal. Another 'aspect currently under consideration is the-feasibility of a multi-purpose OTEC consisting of a mariculture. plant utilizing the nutrient-rith discharged sea water and possibly a desalination plant and air c conditioning facility. An OTEC/mariculture/desalination/air conditioning complex of:,this nature would be an efficient application particularly for small scale OTECI. plants. In summary, the island of Saipan, particularly Bah ia Laulau, as a potential OTEC site looks very promising from a physical environmental point of view. . The thermal resources available are close to shore making the concept of a coastal OTEC plant a very viable one. Caution , however, needs to be exercised in the actual site selection to position' the plant in an area least exposed to adverse physical conditions such as faults, typhoon generated waves and proximity to shore. 144 POTENTIAL ENVIRONMENTAL IMPACTS RELATED TO@ OTEC DEVELOPMENT Evaluation of potential environmental impacts associated with Pilot Plant deployment and operation is presently a matter of conjecture since little data has been collected near an operating OTEC plant. During the first deployment of Mini-OTEC at Keahole Point, Hawaii, :tiie number and species of fish attracted to the platform were monitored (Nolan, 1980). Environmental monitoring for the OTEC preoperational platform (OTEC-1), also near Keahole Point, has also been completed (Menzies et al., 1980). Several reports have preliminary data regarding potential environmental impacts associated with OTEC plants. The full range of environmental issues surrounding OTEC development, demonstration and commercialization was described in the DOE OTEC Environmental Development Plan' (DOE, 1979a). An Environmental Assessment (EA) was prepared by DOE (1979b) for OTEC-1. The OTEC Programmatic Environmental Analysis considered the environmental effects of the development, demonstration and commercialization of several OTEC technological designs, plant configurations and power usages .(Sands, 1980). The OTEC Pilot Plant may potentially affect air quality, the terrestrial environment and the marine ecosystem in the vicinity ci:.f the deployment and operation site. Atmospheric effects or climatic alterations fr*o'm carbon dioxide release and sea-surface te Imperature cooling are not an't"icipated to result from Pilot Plant operation. Construction of a Land-Based *Pilot Plant may necessitate the total destruction of the existing terrestrial habitat. Grading for roads, utility corridors and the central utility terminus may result in a change of Jand use from natural to improved (developed) land. The majority of environmental effects associated with Pilot Plant deployment and operation center on the marine ecosystem since it is the source of evaporating and condensing waters and receiver of effluent waters 145 ............. used by the plant. Marine environmental effects associated with the various ............ Pilot Plant configurations being considered can be catego'rizlea as: major, (those causing significant- environmental impacts), (2) minor (those causing ........... insignificant environmental disturbances :and (3) potential '(those occuring 9 onl during accidents). Pilot Plant char'acteris tics and @their corresponding .............. y environmental effects include: ............... ............... 1. Major Effects of Deployment and Oper Source of :Pollution Attraction. of fish, invertebrates Plaf form presence ............ .............. and birds* Organism impingement and entrainment Withdrawal of surface .............. and. dee'p-.Ocean waters ................ Effects on nontarget organisms Discharg6 of;biocides .......... .. .............. Redistribution of ocean properties, Discharge' of waters at particularly nutrients and planktonic or near the thermocline ............... ........ . ..... organisms Toxic, effects on resident organisms Protective'hull coating release' 2. :Minor Effects of Deployment and Oper. Source. of Pollution ............... ................ Ef fects from trace constituent Po*er*, cycle erosion and ........... release on resident organisms corrosion, Habitat destruction and turbidity Implantation of cold-water ................ during dredging pipe and'transmission cable 3. Potential Effects from Accidents Source of Pollution ................ ................. Toxic effects of released working Potential working fluid fluid on resident organisms release from spills or .... ..... ................ leaks ................ ................. Toxic effects of oil on resident Potential oil releases ................. organisms ................. ................ The Pilot Plant will serve as an artificial reef and provide a habitat for a large number of organisms. The increased population near the plant win ................. compound environmental impacts by exposing greater numbers of organisms ............... ........ ....... ................. ................ ... ...... ................. ............. . .. 146 to the effects associated with routine plant operation, such as entrainment and impingement and risk of nonroutine events such as spills.. a Preliminary (order-of-magnitud.e) estimates indicate that the most serious marine ecosystem effects caused by Pilot Plant operation are associated with the seawater intake and discharg6.: The Pilot Plant will withdraw and dischage approximately 100 times more' water than a similarly sized fossil-fuel or nuclear power plant. The potential impacts associated with seawater withdrawal and discharge include entrainment of larval stages, impingement of ecologically and commercially important species, toxic substance release and ocean water redistribut ion. 1. Entrainment of ichthyoplankton (fish eggs and larvae) and meroplankton (benthic invertebr.ate eggs and larvae) may reduce adult populations downstream of the plant. Around islands' the maintenance -of a is vit al to adult: population larval population near the spawning site existence. 2. Impingement of organisms on the intake screens may:.reduce the population of ecologically or commercially important species in the vicinity of the plant. Data on platform attraction rates, species :affected by impingement, impingement rates and mortality rates have be@n collected during operation of OTEC-1, a converted T-2 tanker that tested various OTEC plant components off Keahole Point, Hawaii in 1981. 3. Biocides (chlorine and its seawater-reaction products) and protective -,hull coatings released from the Pilot Plant may be toxic -to resident organisms or taken up in the tissues of ecologically or commerciall@. important species (Rowley, 1980). Descriptive studies on the seawater ch :emistry of chlorine, acute/chronic toxicity studies and food-chain investigations are required for evaluating'the effects of these releases. 147 4. The release of working fluids and oil during a catastrophic accident could significantly impact the marine environ ment. The risk's of accident occurrence should be assessed and a spill contingency plan prepar'ed. 5. ..The discharge of nutrient-enriched deep waters within @f he surface of the layers of the water column may increase the primary productivi receiving waters. Data for evaluating nutrient redistribution effects on the ecosystem includes physical-model predictions", phytoplankton ''uptake rates and food-chain investigations. Results of physical' models@', 'Will provide estimates of the plume stabilization depth, downstream mitrient concentrations and area affected. Phytoplankton uptake rates and food-chain investigations are important for estimating the increase in; biomass and its resulting effect on trophic level structures. T o' 'assess the potential effects of Pilot Plant deployment 'and operation the ecological, physical and chemical characteristics. of -the site must be determined. prior to plant deployment and an environmental monitoring plan (for evaluation of plant operational effects) prepared.: After Pilot Plant deployment environmental monitoring data must be obtained used for determining the long-range environmental effects ass Iociate.d'' with the Pilot Plant operation. These data will be used in regulatory compliance reporting, but should also be compared with environmental predictior@s made prior to deployment. in order to validate theoretical results. RISK OF CREDIBLE ACCIDENTS RELATED TO OTEC DEVELOPMENT Operations in the marine environment present several unique hazards or potential for accidents. Collisions, extreme weather conditions, military or political terrorism and human error may endanger the safety of the platform crew and the population served by the Pilot Plant. Pilot Plant crew 148 members, population adjacent to the plant and communities served by the plant will be exposed to potential accidents and power failures. Ship traffic around the Pilot Plant must be..:-carefully monitored to minimize the potential for collisions. Large volumes of working fluid r (ammonia) will be stored aboard the Pilot Plant and,@present certain health hazards should a collision or large leak occur. A. '@pill contingency plan should be prepared after the Pilot Plant platform and'deployment sites have been selected. 149 LITERATURE CITED Dames and Moore Inc. 1979. Environmental Impact statement for Guam OTEC Pilot Program. Lassuy, D. R. 1979. Oceanographic conditions in the vicinity of Cabras Island and Glass Breakwater for the potential @developm .ent of Ocean Thermal Energy Conversion on Guam. Univ. -of' Guam': Narine Lab. Rept. No. 53. Menzie C . A.', D. Frye and D. Hazelwood. 1980. OTEC-1 'enviro n*mental monitoring program. Expanded abstracts of the, seventh:.'o'cean energy conference, Wash., D. C. 4p. Nolan, R. 19@8 0. Fish associated with the first deployment, of Mini-OTEC. ORCA, 'Honolulu, Hawaii. 50p. Rowley., D. M., 1980. Analysis of biofouling communities on,,settling plates at the proposed ocean thermal energy conversion .(OTEQ) site off Guam. Guam Energy Office. 89p. Sands, M.. D. (ed.). 1980. Ocean thermal energy@ conversion draft pro rammatic environmental analysis. Prepared foi, U. S. Dept. of Energy, Contract No. W-7405-ENG-48. Interstate Electronics Corp. Anaheim,- CA. U. S. Department of Energy, 1979a. Environmental development plan. OTEC. August 1979. U. S. DOE Assist. Sec. for Energy Tech., Asst. Sec. '.for Environ. 48p. 1979b. Environmental assessment, ocean thermal energy conver--si-on-7-0-TEC) program. Preoperational ocean test platform. U. S. DOE, Asst. Sec. for Energy Tech., Wash...,, D. C. 20545. DOE/EA-0062. 381p. 151 GENERAL DISCUSSIONS PHYSICAL RESOURCES Physical resources in Bahia Laulau include the reef beaches and isolated mineral deposits. Reefs and associated flora and.fauna are one of the most valuable resources islands have to offer and,this is exemplified by the available resources of Bahia Laulau. The most importanf@ resources on the reef are the edible fishes as well as numerous other. edible flora and f auna. Food fishes are described in the fish section of this:! report. In addition, the coral community represents an important resource, for without it most other forms would not congregate here. Beaches' represent a significant, physical resource both from an aesthetic point of view as well as the po .tential 'for sand mining. A reasonable sized deposit,,of :Manganese is located. on the Hagman Point side of the bay. Details ,of these mineral deposits, are discussed the Geology section. One important resource not to be overlooked- in Bahia Laulau is the temperature differential' between deep cold water:. and warm surface water. This temperature differential is the basis for ',OTEC development and the premise upon whicl@ this study was undertaken. BIOLOGICAL RESOURCES Biological resources include fishing and harvesting of .algae, coral and clams. Fishing represents the single largest biological resource for the people of Saipan Harvesting coral, algae and other forms'such as clams is a viable resource in Bahia Laulau. However, strict regulations and limits must be placed on these resources since they can be depleted rapidly leaving an irreparable condition. At the present time, harvesting of coral is illegal in the GNMI except by permit. 152 RECREATIONAL RESOURCES Recreational uses of Bahia Laulau include all activities associated with the beach and ocean. These include boating, fishing, diving, sunbathing, picknicking or just appreciating the natural beauty of this idyllic bay. Observations during our field trip indicate that the bay is used by fishermen both from boats and on the reef including netting and spearfishing. Small boats can also be launched on the beach or over the reef near the small channel at Site 2, weather permitting. Numerous scuba divers were observed during our field trips. Sunbathing is an ideal recreational use for Bahia Laulau. Snorkeling and Scuba Diving Bahia Laulau is one of the favorite areas for recreational and tourist-related diving and it affords one of the only. sites along the east coast of Saipan where divers and spearfishermen can. make an easy beach entry., A well-protected cove (near Unai Bapot) with@ a narrow cut through the reef an entry and exit point for -divers and small boats. Dive shop owner and scuba instructor Ben Concepcion reports that all dive tours to Saipan (mostly from Japan and Guam) make at least one dive in Bahia Laulau. He estimates a total of 75-100 tourist :divers visit this site each month. In addition to this number, local residents frequent the Bay for spearfishing, lobstering and other recreational uses. Fishing and Boating Obs iervations by team members during this study, informati@r.i from the local Fish and Wildlife Division and interviews with Mr. Ben Concepcion and other local fishermen all indicate that Bahia Laulau is important and frequently used for subsistence and light commercial fishing. Th e reef flat 153 is extensively utilized for talaya (throw-net) fishing, gill ne ts, pole casting from the reef edge, octopus hunting and lobstering and crabihg'at night. A limited number of fishermen bottom fish' and troll in the Bahia Laulau area. According to local fishermen, more fishing would occur if a better boat launching site and channel were available in the Bay. At the present time, only small boats can be launched via the cut in the reef. The trip around the southern tip of the island and Naftan Point u to B'ahia Laulau is long and usually rough and it is costly in terms of, time an'd.@ fuel.: Both boaters: and divers expressed a desire to have the present channel (cut) widened and deepened which would result in increased use of the Bay for fishing and recreation. RESOURCE DEGRADATION Some damage to the coral community throughout' Bahia Laulau is presently underway as a result of an influx of Acanthaster',pla nci (crown-of- thorns starfish). Numerous individuals (more than 10,0: large individuals) were observed at each site with the majority inhabiting,.the lush coral community:. at Sites 2 and 3. Individuals collected -,duiing our survey measured 'nearly 50 cm (20 in) representing some of the largest specimens observed anywhere, particularly in these waters.- Damage to the coral reef is evident which suggests the condition has been progressing for sometime now. An Acanthaster outbreak for Saipan was predicted for the summer of 1981 on the basis of heavy rains in August 1978 (Birkelan'd, 1982). This outbreak was observed in August 1981 by Joaquin Villagomez, then chief of the Division of Marine Resources, Saipan. The starfish were first observed in southern Saipan and they were described as "a moving front comprised of several thousand individuals." It is likely that the Acanthaster which now 154 inhabit the reefs of Bahia Laulau are from this 1981 infestation as the large size reported (up to 50 cm) would be expected in a 41 year-old population (settled out of the plankton to form juveniles in August 1978). Minor degradation to the coral community offshore and on the reef flat has also resulted from sediment runoff particularly in:..the vicinity of Site 2. Storm water drainage carrying large quantities of silt pours into the bay near Site 2 through a small drainage fitted with what appears to be a box culvert constructed sometime during the Japanese occupation. Water quality analysis indicates a higher degree of turbidity 'from suspended solids pouring into the bay at this point. In addition, total and fecal coliform counts are higher here than in other areas of the bay. The increased use of Bahia Lau.lau and intensive subsistence fishing and trampling of corals on reef flats has contributed to 'the gradual decline of food fishes in the area. Local fishermen note that fish populations on the reef flats or close to the shore have gradually declined in the last ten years or so as :a result of increased fishing in the area. UNIQUE AREAS AND FEATURES Bahia Laulau is a unique bay in itself both from the resource and aesthetic point of view. Specific unique areas include Forbidden Island @nd Hagman Point, the reef flat and beaches between Sites 1 and 2'. natural :cut in reef at Site 2 where boats can enter and exit the bay and the protect'ed cove at Site la. These areas are unique because of their natural beauty and aesthetic.. value as well as their value as a resource for enj.oyment or livelihood. 155 LITERATURE CITED Birkeland, C. 1982. Terrestrial runoff as a cause of outbreaks of Acanthaster planci (Echinodermata: Asteroidea). Mar.Biol. 69, 175-185. 156. 157 CONCLUSIONS GENERAL Bahia Laulau has highly diverse terrestrial and marine ecological communities. Bahia Laulau is important for subsistence: fishing: and various recreation uses for local residents and tourists* alike. Ancient Chamorros and military personnel- (both @Japanese and American) have utilized the bay Which is rich in resources. 'Bahia Laulau is known as a mating ground and, the isolated: beach areas are utilized as nesting sites for sea turtles. Nater quality within the bay is generally excellent with some localized degradation following heavy rains. RESOURCES The entire bay is rich in resources which may play an important role in the future development of Saipan and the Northern' Mariana Islands. These resources include the following: Manganese Limestone Beach sand 7 Tropical forest lumber (Breadfruit, Ifil, Kama'chiie) - Cold deep water and warm shallow water close to: shore -The ta'gpochou formation cropping out immediately north of Beach Road at Unai Bapot appears to possess the requisite density required for construction aggregate. OTEC Adequate near-shore cold water exists at appropriate depths for the proposed OTEC facility at the Hagman Point site. Providin g that effluent is not discharged in the' vicinity of the near-shore reef area, impact to the marine environment due to effluent discharge would be minimal since currents at the discharge point move out to sea. - The site is poor from an engineering point of view because of instability due to faults in the area and heavy surf and constant wind activity from the prevailing east-northeast direction. 158 Accessibility to the proposed OTEC site is non-existent and would pose severe problems during the development of infrastructure because of its general isolation. - Highly fractured bedrock, steeply dippin' soft and weathered 9 volcanic strata, extremely steep slopes, high relief,@-sparse vegetation and low-level shock waves from earthquakes and storm swells contribute to lessen safety factors at Site 1. Many slopes at Puntan Hagman are barely stable from the construction point of view. - Tropical storms and typhoons would probably attack the base of Site 1 directly promoting active coastline retreat arid. generating sufficient submarine instability to initiate submarine slides directly off the site. Engineering and construction costs to build:an OTEC facility would be extremely high because of its isolated nature and the general geologic constraints of the site. General working conditions for offshore pipe placement would be extremely poor and limited to only a few weeks a year due to rough water conditions. 159 RECOMMENDATIONS General Control development within Bahia taulau to preserve. its natural beauty and water qualit Y! Properly manage and conserve all Fesources in B ahia Laulau for their ultimate future protection. Subsistence, recreational and small scale commercial 'fishing: should be supported and expanded for under-utilized s pecies.: Access for boating through the existing natural cut at- Bapot Beach should be improved, Continue water qualit monitoring within the Bahia: Laulau area. Resources Further studies to determine the quantity and qu'ality'of manganese deposits at Hagman Point should be undertaken. Limestone deposits throughout the bay should be studied to determine the nature and extent of future quarry sites. Providing thq 0TEG facility is a pr9y-e4, the following are needed: T_ Detailed engineering studies to determine the suitability of the OTEG site'at Hagman-Point. Specific detailed current studies at the OTEC site to determine the. zone of. mixing This would include shallow to deep underwater current studies over a one year period, Additional bottom profiles at the. OTEC site to determine precise profile for pipe placement. bottom Heavy construction planned for sites on Marianas and Tanapag formations should, be preceeded by thorough subsurface investigations including geophysical surveying and borings., APPENDICES APPENDIX A TABLES 1, 2, 4-17 I Table 1. Rock units mapped in the vicinity of. Bahia Lauliu, Saipan Map Engineering 2 General Engineering Name symbols General Lithologic Descriptions Designation or Construction Considerations Be"Ich Qrb Intertidal and low supertidyl san d Beach Sand Easily excavated waterworn poo Deposits wid gravels including recently ce- graded shell and coral fragment mrnted beacbrock. Predominantly 61- Bearing capacity good if dry. careoits, bioclastic, and poorly Satisfactory construction materi sorted. Fast coast Qrb may contain significant volcanics. Emerged Orl Poorly sorted calcareous sands and Beach sand Same as above Htnesands gravels occurring as supratidal storm deposits; may he mixed with alluvium washed off local slopes. Alluvitim Qa Presently accumulaLfiig gravelly Alluvium Easily excavated; very poor gra alluvium trinsported off hilly terrain Non clay material too weathered by deeply incised ephemeral streams. aggreg-ite. Grumbly, Includes significant clay lenses and occasional debris flows. Colluvium Ql, Qor Deposits formed by mass wasting. Slide Colluvium Some rockslides may have appre Qx blocks, slump blocks, landslides, soil aggregate-quality material. creep and talus. Tanapag Qta Coralgal reef limestone and detrital Firm Pinnacled, cavernous surface on limestone. Partially recrystallized, Porous cavernous subsurface. May be c highly fossiliferous, tan to white, Limestone or fria6le. Excavations require porous. Outcrops discontinuous. Forms ling and blasting. Adequate onI lowest 2-10 m, benches where it rests cohstruction. on eroded Mariana or Tagpochau abrasion terraces. Tc,rrace Qp Well- strati fled reddish argillaccous Partially Friable and easily excavated. Deposits sandstone composed of reworked vol- 'Weathered limited outcrops. GOnerall*yun@a volcanic pebbles. Andesite .-factory engineering material. Table 1. Continued. Mariana Qmh, Qmm Coarse to fine-grained massive (Qmtn), Firm Compact to friable, often cave Qmr rubbly (Qmr), sometimes Flalimeda-rich Porous Faults and joiiits prevalent. G (Qmh) Iagoonal white to tan limestone Limestone excellent construction material with occasional reefal units. Major compact terrace former throughout CNfAl. 100- 150 m thick. Tagpochau Tti, Ttt White to pink, ofteit v-ariag.ati,@.d., -Very Compact *lAmestoncs are very firm and c Ttd, Ttni generally compact, laguoinal-and -Limestone Excellent construction aggrega off-rcef limestone-, significant (Tti, Ttt) decorative stone. deepwater sandy units (the Donni uticonforntity I't r member (Ttd)).-Inequigranulir (Tti), clayey Very bad qualities: Expandable marly (Ttm), and transition nirmbers Volcanic no bearing strenght; unstable. MO. May be argillaccous and Sediments tuffaccous. Thickness about 200 m. (Ttd)' Dciisinyama Tdcq Interbedded well-stratified tuffarrous Weathered Vuggy; porous to compact, fri qu-irtzose sandstones and conglemer Andesitic Pebblesweathered. Quartzose. m ates. Ilematic, reddish-brown cherty Sandstone hardand abrasive. Generally t matrix. Grains mostly volcanics, and factory construction material. quartz and chert. Sulfides. Thickness Conglomerate about 30 m. Hagman Thc, Thl) VoIcanoclastics: Volcanic-derived Partly Loose, fresh to partly weather tuffaceous sandstones, lapilli-tuff, Weathered volcanic detritus and altered medium tuff, breccia, conglomerate, Andesitic tuffaceous matrix. Easily excav andesite glass and rock fragments. Sandstone boulders arid cobbles make exc Pebbles and boulders are porphyritic. and aggretage. Expandable clays m Dark gray, pink, olive: thickness Con glomerate slopes unstable. about 300 m. Footnotes IGeologic mapping, names, symbols, and formation thickness after Cloud, et. al. 1456. 7r,ngineering designaflon and qualities after Nicol, 1956. Table 2. Soil units mapped in vicinity of Bahia Laul au, 'Saipan. NAME 1 General Description Construction Considerations 2 Saipan - Chacha Mostly deep clays; neutral,.. Unsuited for heavy construc- Association firm yellowish brown on gently tion. Slow drainage. High sloping hilly terrain over shrinkage sticky clays with limestone. limestone boulders. Good subgrade fill. Dandan Soils Mostly clay loam; moderately Fair for light structures, deep, neutral to alkaline, Unsuited for heavy construction. friable, brown; on gently Good subgrade, excellent topsoil. sloping terrain over limestone. Lito-Akina-Dago Deep clays; acid, firm, reddish, Poor for heavy structures. High Association on gently sloping to hilly shrinkage; Sticky: terrain over volcanic rocks. Poor drainage. Chinen Soils Mostly 'Clay loam; shallow, alka- Fair for light structures, Slow line, stony, on gently sloping drainage, high shrinkage, to steep terrain over limestones. fair topsoil. Shioya Soils Mostly loamy sand; deep, calcare- Good for light structures. Very ous, light colored, on nearly ..rapid drainage. Good compaction, level coastal flats. good subgrade and fill. Poor top Soil. Rough Stonyland on Very shallow stony solid;. mostly Too shallow to rate. B*edrock Limestone on hilly -and 9teep'"teirrain, excellent for structures (if numerous limestone outcrops. sited properly). Rough Broken Land Clays; shallow and very shallow, Fair for' light ''Structure s, high 4c-i-d,. reddish, highly weather- shrinkage. Slow drainage. ..ed-volcanic-rocks@ PI many gullies-.-- Quarries No soil cover; limestone Not applicable. quarries Fo?tnote: 2Soil mapping, names,. and descriptions taken from McCracken and Zarza (1954) Engineering. soil. data from McCracken (1955) Table 4. Site comparison summary. SITE I SITE 2 SITE 3 SITE 4 Geologic Evaluation Sabatinii Unai Unal Unal Criteria Kagman Bapot Laulau Dandat Rock Units Volcanics and lime- Volcanlcs and..Iime- Limest es-.- Normal- Limestones- I (composition and stones. Many joints and stoiies.. Normal strati'' aphic sequence. and pinnacled 7, stratigr structure) faults. Very complex. _.,graphic's7&lucn_ce_'. No Minor faulting. and Mariana. faulting. Abundant - ...... jointing. Soil Units Mositly shallow and Sticky clays upslope. Shallow and rocky. Some No soil. Esse rocky. Shallow and rocky pockets of clay. bedrock. downslope. Limesatids. Slope Stability Extremely unstable Fair. Volcanics upslope Good Excellent slopes. Rapidly changing show slumping and creep. slopes and coastline. Danger of Flooding Low High. Vulnerable to Moderate. Somewhat None typhoon-related swells vulnerable to flash and flash flooding. flooding and waves. Alluvial Processes Active gullying and Active transport of Minor alluvial transport. None soil removal from steep boulders, sand and clay terrain. down ephemeral streams. Subsurface Very porous limestones Very porous limestones Very porous limestones. Very porous from .faulting and on low porosity solution. volcanics. Goastal Configuration Faces south cliff; and Faces south; beach and Faces southeast; beach Faces iiorthea headlands vulnerable road vulnerable to vulnerable to typhoons Vulnerable to to typhoons. typhoons. c1liffline receding tradewind ene Economic Resou rces Manganese; Scenic Recreational- - '.Recreational. '.Aggregate.; S Table 5. Temperature and Salinity at the Listed Dept hs with Corresponding Calculated Density (November 4, 1982). m meters, OC = degrees centigrade, ppt = parts per thousand, g/CM3 = grams per cubic centimeter. Temperature, salinity and -density* values were extrapolated where noted by ail asterisk. Depth Temperature Salinity Density (M) (OC) (ppt) (g/CM3) Surface 28.4 34.4 1.022 229 22.5 35.1 1.025 305 12.3 34.5 1.027 @381 9.3 34.4 1.OZ8 457 7.4 34.5 1.028 :.5Z5* 6.4 34.3 1.026 .550* 4.4 34.1 1.022 Table 6. Checklist of plants by site. A Abundant, C Common, S Seldom, R Rare. P1 Type, (T) Tree, (S) Shrub, (B) Bush, (F) Fern, (V) Vine, (W) Weed, (G) Grass. Dates: 11/82, 2/83, 5/83, 9/83 Plant Site Si SCIENTIFIC NAME ..Common Name-.. Chamorio.Name... .TYP6. 1 Leucaena leucocephala Tangan-tangan (T) C Leucaena insularum var. guamense -Tangan-tangan (T) C Casuarina equis tifolia Ironwood Gago (T.) S Miscanthus floridulus Sword-grass Neti (G) A Scaevola taccada Nanaso (S) Bidens pilosa Beggar's-Tick (W) C Stachytarpheta indica False Verbena (W) C Hibiscus tiliaceus Hibiscus Pago (B) Ipomoea pes-caprae Beach Morning- Alalag-Tasi (V) Glory Pluchea indica (S) Wedelia 61-f-lora Beach Sunflower (V) Hernandia nymphaeifolia Nonak (T) Cassytha filiformis Mayagas (T) C Barringtonia asiatica Fish-kill-tree Puting (T) Desmodium unbellatum Palaga Hilitai (S) Mucuna gigantea Small Seabean Gayi Dikike (v) Sophora tomentosa (S) R Vigna marina Akangkang (V) Manulasa Pemphis acidula Nigas (S) Thespesia populnea Banalo ':(T):"-*"" Cocos nucifera Coconut ...Niyog,. (T) C To-lubrIna asiatica "-.Gasoso... Bikkia mariannensis Gausali (S) .-C Nger Allophylus timorensis Ca-Hiparpa candicans Masiksik Clerod@_n_drum inerme Lodugao (V) C Guamia mariannae Pai-pai Ochrosia mariannensis Langiti (T) 0. oppositifolia Fago (T) Xsplenium nidus Birds-nest-Fern Galak Feda (T) Uycas circinalis Cycad Fadang (T) Davallia solida Pugua Machena (F) Table 6. Continued Plant Site SCIENTIFIC NAME Common Name Chamorro Name Type Macaranga thompsonn Pengua (T) Melanolepi s -multi glan dulosa Alom (T) Phyllantus marianus Gaogao-Uchan (S) R Flagellaria indica False Rattan Bejuco-halomtano (G) Mammea odorata Chopak (T) Abrus precatorius Coral Bean Kolales (V) Caesalpinia major.. Wait-a-Bit Pakao (V) Cynometra ramiflora Gulos (T) Intsia bijuga If et (T) Artocarpus sp. Breadfruit Lemai (T) Ficus prolixa Banyan Nana (T) Pisonia grandis Umumu (T) R Pandanus dubius Pandanus Pahong (T) R P. fragrans Pandanus Kafu (T) R Piper guahamense Wild Piper Pupulu-n-Aniti (S) Microsorum punctatum Strapleaf Fern Galak Dalalai (F) Phymatodes scolopendria Kahlao (F) Guettarda speciosa Panao (T) Morinda citrifolia Indian Mulberry Lada (B) Psychotria mariana Aplokatina (T) Randia cochinchinensis Sumac (T) Cestrum diurnum China Inkberry Tintan-china (B) R DicrTnop inearis Savannah Fern (F) R Dimeria chloridiformis Grass. (G) C Pennisetum polystactiyon Foxtail (G) R Myrtella bennigseniana (S) C Messersclim-idia argeii-tia Hunig (T) Annona retic:0-ata Custard-Apple (T) Uvaria odorata (T) _11ang-Ilang Aglaia mariannensis. Mapuano (T) Areca cathecu Betel-Nut Palm Pugua (T) Annona. muricata Soursop Laguanaha (T) R Carica p Lplya Papaya Papaya (T) Musa sp. Banana Chotda (T) Table 7. Checklist of terrestrial vertebrate fauna In the vicinity of Bahia Laulau, Saipan. For.occurance A abundar occasional, R Rare. E.= expected to occur.b. .ut.-not -observed.- _'Date .s 11/8'2', 2/83 and 9/83. Common Name Species Chamorro Name Site I Site 2 AVIFAUNA Bittern, Yellow (Chinese) ixobrychus sinensis Kakkag C C TuTa-T- Booby, Brown L @c. aster Luao Attilong 0 Booby, Red-footed Sula sula Luao Tallsal. E Curlew, Bristle-thighed 14-umenius tahittensis Kalalang E R Dotteral, Mongolian Chara;3ri s mongolus Dulill E R Dove, Fruit Ftilinopus r@@ Totot 0 0 Dove, Ground Gallicolumba xanthonura Paluman Apaka/Fachi R 0 Dove, Philippine -turtle Streptopelia Wtorquata Paluman Senesa/Apu G A Egret, Cattle Bubulcus ibis Chuchuko E - Egret. Plumed intermedia Chuchuko E - Egret, Reef (Heron) E etta sacra Chuchuko Attflong E 0 e Fantail, Rufous-fronted RFiDidura ruflfrons Chichirika, Naabak A A Honeyeater, Cardinal zome a cardinalis Egigi 0 C Honeyeater, Golden Cleptornis marchel Kanario 0 0 Kingfisher, Collared R-a I n chloris Ic 0 Shihig E C Mannikan, Chestnut Lo , W, C 0 Plover, Golden Pluvialis do-minica Dulill 0 C. Plover, Grey Pluvialis s u t rola Dulill - E Reed-warbler, Nightingale AcroceqhaTu_s_I_uscInIa Kaga Karisu E R Sandpiper, Common Dulill R Sandpiper, Sharp-tailed Calidris acuminata Dulili .7 E Sparrow, Eurasian Tree Passer montanus -Gaga Pale'- G 'A 0' Starling, Micronesian X, Icnis opaca Sali C%_ Ita vanikorensis Swiftlet, Vanikoro 0 oca Yayaguag, Chuchaguak E Tattler, Grey-tailed TI-eteroscelus @@i es ...... E Tattler, Wanderling Fleteroscelus Incanus. ....... *E Tern, Common Tterna hirundo Q, Tern, Brown Noddy Tnous sto Rus Fahang--- A. E- 9 S -C, , * .Tern, White Uv 2-Fs alUa- Chunge C Tropicbird, Red-tailed PS-a-e Th'i@n_r ub rl cau da Utag, Fagpl Agaga E Tropicbird, White-tailed PE-aeftli-on epturus Utag, Fagpi Apaka 0 Turnstone, Ruddy A-re-n--arl-a Interpres Dulill E. R Whimbrel N-u-me-n-Tu-s phaeopus Kalalang E White-eye, Bridled To-sterop c-onspicillata Nossak, Nosa 0 C Total Species Observed 17 20 Total Species Observed/ Expected 28 27 Total Species Observed (All Sites) 29 Total Species Observed/ Expected (All Sites) 34 Table 7. Continued@- Common Name Species Chamorro Name Site I Site 2 REPTILES,AND- AMPHIBIANS Anole Anolls carollnensis E 0 Lizard, Monitor Va-ranu-s-MAI-cus E 0 Skink, Blue-tailed Emola cyanura 0 C Skink, Brown Emoia sp 0 C Skink, Green-tailed Ua-mprolepis s dina E E Snake, Blind Typhlop-s- bra-minus E E Toad, Marine Tu_ To-m -ar I n u s 0 C MAMMALS Bat, Marianas Fruit Pteropus marlannus Fanihi E E Cat, Feral Ve catus E E Deer, Sambar Ue-rv1@9-unicolor marlannus Benado E E Dog, Feral U_a_nr9_7a_m_iU_a_rTs_ 0 0 Mouse, House M u -sm U-s-c- _U1 u _s Chaca E 0 Rat, Norway Ta-ttus norvegicus Chaca E E Rat, Polynesian Rattus exulans Chaca E E Rat, Roof R-attus rattus Chaca E E Shrew, Musk Tu _nc u s FFn u s E 0 Table 8. Checklist of benthic algae and seagrasses at five sites in Bahia Laulau, Saipan, November 1982. IRF inner reef flat, ORF outer reef flat, RM/RF reef margin and reef face, ST ='submarine terrace. SITES 1 la 2 3 4 3-6m :JU-5m 20-10m SPECIES ST ST IRF ORF RMIRF ST.RF ST ST CYANOPHYTA (Blue-green algae) Anacystis sp. x x -Calothrix sp. X,. Microcoleus lyngbyaceus x x x x x Schizothrix dalcicola. x x x x X, -x x S. mexicana. x x x x X. x x CHLOROPHYTA (Green algae) Enteromorpha. clathrata x x Chaetomorpha: crassa x x x Tfi crodictyon okamurai x x X, x x x Bryopsis pennata x x x x B. hypnoides 'XI x x Taulerpa cupr6ssoides x x x x filicoides x racemosa x x X X x x T. serrulata x x x sertulari x x X, x x oides C. urvilliana x x C. verticillata x Zhlorodesmis fa Lstigiata x x x X: :x x x Halimeda discoidi aa x x R . opuntia x x x x x x x valasquezii x x x 'Rhipilia oriei@_talis x Tydemannia expeditionis X* Udotea argentea x :k x x U. geppi x x x -Hoergesenia forbesh x x . . I Boodlea coFnposita x x x x @x x Cladophoropsis membranacea x x x x sundanensis x x -5ictyosphaeria verluysii x x x x Acetabularia moebii x x x x Reomeris annulata x x x x N. vanbosseae x x x x Table 8. Continued SITES 1 la 2 3 4 3-6m 10-5m 20-10m SPECIES ST ST IRF ORF RM/RF ST RF ST ST PHAEOPHYTA (Brown algae) Lict ota bartayresii x x x x x x Lobophora variegata x x x x Padina minor x x x P. tenuis x -gargassum cristaefolium x x x S. Polycystum x x Turbinaria or-nata x x x x x RHODOPHYTA (Red algae) Aciinotrichia fragilis x x x x x Galaxaura filamentosa x x x x x G. marginata x x x x x x -ff.. oblongata x x X. x x x x (!@elidiella acerosaL x x x x Gelidium crinale x x x x x (77 pusillum x x x x Dagora sp. x x x Pterocladia parva x x x Amphiroa fragilissima x x x x x x x x A. - foliacea x x x x x Jania capillacea x x J.' decussato-dichotoma x Mastophora rosea x x x X,. x x x Porolithon onkoides x x x x x x x Sporolithon sp. x X: x x x Champia parvala x x x -Rhodymenia sp. x x x x x x Acanthophora spicifera x x x Caloglossa sp. x x Zentroceras clavulatum x x x Ceramium gracillimum x x x Laurencia sp. x x x Leveillea jungerma nioides x x x x x T7olysiphonia sp. x x x x Spyridia_ filamentosa x x TolypiocladLa gl ulata x x x ANTHOPHYTA (Seagrasses) Enhalus acoroides x TAXA RECORDED 15 37 15 26 26 50 25 45 28 GRAND TOTAL - 69 Table 9. Total number of planktonic organisms per sample. NOVEMBER 1982. Date: 11-82 Location Surface Surface Ub-lique Oblique Taxa Sampling Number P-1 P-2 @P-3 P-4 Chrysophyta Bacillariop.hyceae (Diatoms) Centrales Coscinodiscus sp. A 2 2 0 Protozoa Foraminifera Orbulina universa 30 3 6 Radiolaria Species A 8 4 Cnidaria Siphonophora 32 1. Medusae 0@ 0 Annelida Polycheate: larvae 2 3 0' 0 Arthropoda/Crustacea Cladocera Evadne sp. A Ostracoda 0 2 Euconchoecia. sp. A 0 0 Cypridina sp. 14 3 2 9 Copepoda Uni@: ntified species 146 19 40 40 Calanoid sp. A Calafioid sp. B Euchaeta sp. Candacia sp. Acartia sp. Eucalanus sp. -Centropagus Oncea sp. Copilia sp. Coryceaus sp. Sapphirina Sp. Onidentified Cylcopoidid 2 0 3 2 Malacostraca Mysidacea sp. A 400 300 44 73 Mysidacea sp. B 224 188 6 20 Cumacea sp. A 1 0 0 1 Isopoda sp. A 2 2 0 2 Amphipoda sp. A 10 12 0 0 Decapoda/Shrimp mysis sp. 66 12 11 16 Decapoda/Crab zoeae sp. 4 0 0 1 Decapoda/Crab megalops sp. 10 6 2 4 Table 9. Continued. Date: 11-82 Location Surface Surface Oblique Oblique Taxa Sampling Number P-1 P-2.. P.-3 P-4 Mollusca Gastropoda Gastropod veliger larvae 2 3 1 0 Pteropoda Cresius acicula 0 Unidentified sp. A 1 0 0 Unidentified veliger capsules 16 200 55 17 Cephalapoda (squid) Chaetognatha Sagitta sp. A 4 0 4 15 Heteropoda Chordata. Urochordata Thaliacea (Salpa) Salpa sp. A 8 0 0 0 Vertebrata Osteichthyes Fish larvae 42 15 11 8 Fish eggs "round" 20 12 Fish eggs 11 oval" Miscellaneous 1 0 0 0 #Individuals /cubic meter 10.11 7.58 1.95 2.25 Total Species 25 18 14 18 Total No 1048 786 202 233 Table 9a. Total number of planktonic organisms per sample. FEBRUARY 1983. Date: 2-83 Location Surf ace Oblique Surface Oblique Surface Oblique Taxa Sampling Number P-5 P-6 P-7 P-8 P-9 P-10 Chrysophyta Bacillariophyceae (Diatoms) Centrales Coscinodiscus sp. A Protozoa Foraminifera Orbulina universa Radiolaria Species A 100 100 1000 650 1000 2400 Gnidaria Siphonophora 3 3 Medusae Annelida Polycheate larvae Arthropoda /Crust acea Cladocera Evadne sp. A 2 Ostracoda Euconchoecia sp. A Cy ridina sp. Copepoda Unidentified species Calanoid sp. A 8 .:9:. 27 Calanoid sp. B .1 Euchaeta sp. -6 2 Candacia sp. 1 2 Acartia sp. 1 1 2 2 Eucalanus sp. 1 Centropagus Oncea sp. 15 4 Copilia sp. 2 3 Coryceaus sp. 8 0 5 6 Sapehirina sp. 11 7 Unidentified Cylcopoidid Table 9a. Continued. Date: 2-83 Location Surf ace Oblique Surface Oblique Surface Obliq Taxa Sampling Number P-5 P-6 P-7 P-8 P-9 P-1 Malacostraca Mysidacea sp. A 8 6 Mysidacea sp. B Cumacea sp. A Isopoda sp. A Amphipoda sp. A 1 Decapoda/Shrimp mysis sp. 1 6 8 4 Dedapo'aa/Crab zoeae sp. 4 4 2 2 Decapoda/Crab megalops sp. Mollusca Gastropoda Gastropod veliger larvae 1 7 13 21 30 Pteropoda Cresius acicula Unidentified sp. A 2 1 Unidentified veliger capsules 75 70 Cephalapoda (squid) 1 1 1 Chaetognatha Sagitta sp. A 13 16 fleteropoda I Chordata Urochordata Thaliacea (Salpa) Salpa sp. A Vertebrata Osteichthyes Fish Iarvae 3 Fish eggs "round" 43 22 Fish eggs "oval" 115 85 5 #Individuals/ cubic meter 1.08 0.97 12'.80 8.81 9.86 23.57 Total Species 6 3 24 23 3 7 Total No. 112 101 1327 914 1023 2444 Table 9b. Total number of planktonic organisms per sample. MAY 1983 Date: 5-83 Location Surface Oblique Surface Oblique Surface Oblique Taxa Sampling Number P-13 P-14 P-15 P-16 P-17 P-18 Chrysophyta Bacillariophyceae (Diatoms) Gentrales Coscinodiscus sp. A Protozoa Foraminifera Orbulina universa 45 84 16 Railolaria Species A 70 Cnidaria Siphonophora 48 20 34 Medusae Annelida Polycheate larvae 2 Arthropoda/Crustacea Cladocera Evadne sp. A 60 -20 .6 Osfracoda Euconchoecia sp. A Cypridina sp. 4 Copepoda Unidentified species 66 Calanoid sp. A 400 2 A@6 -Calanoid sp. B 20 100 Euchaeta sp. 40 Candacia sp. Acartia sp. 2 Eucalanus sp. T@entropagus Oncea sp. .2 Copilia sp. 4 -Coryceaus sp. 4 2 2 'EjK@hb'su'&R S" IJM M6 M JOE U-F-idpt-i Fed OW f7i v COT) Table 9b. Continued. Date: 5-83 Location Surface Obli que Surf ace Oblique Surface Obliqu Taxa Sampling Number P-13 P-14 P-15 P-16 P-17 P-18 Malacostraca Mysidacea sp. A 4 30 Mysidacea sp. B Cumacea sp. A Isopoda sp. A Amphipoda sp. A 2 4 Decapoda/Shrimp mysis sp. 4 20 16 24 16 35 Dec'ap'oda/ Grab zoeae sp. 10 48 115 132 200 200 Decapoda/Crab megalops sp. Mollusca Gastropoda Gastropod veliger larvae 8 20 21 21 8 Pteropoda Cresius acicula Unidentified sp. A 1 2 2 Unidentified veliger capsules Cephalapoda (squid) Chaetognatha Sagitta sp. A 12 52 6 30 30 Heteropoda Miscellanious Invertebrate Eggs 100 150''' 1000 .350 400 400. Chordata Urochordata Thaliacea (Salpa) Salpa sp. Vertebrata Osteichthyes Fish larvae 4 6 2 Fish eggs "round" 12 24 5 15 Fish eggs "oval" Undividuals /cubic meter 2.73 9.28 11.85 .6.86 7.12 7.60 Total Species .13 15 11 12 12 Total Number 283 .962- .1229 711 738 7H Table 9c. Total number of planktonic organisms per sample. SEPTEMBER 1983. Date: 9-83 Location Surface Oblique Surface Oblique Surface Oblique Taxa Sampling Number P-21 P-22 P-23 P-24 P-25 P-26 Chrysophyta Bacillariophyceae (Diatoms) Centrales Coscinodiscus sp. A Protozoa Foraminifera Orbulina universa Radiolaria Species A Cnidaria Siphonophora 53 32 90 90 29 60 Medusae 2 Annelida Polycheate larvae 4 Arthropod a/ Crus tacea Cladocera Evadne sp. A 2 50 26. 18 12 OsGracoda Euconchoecia sp. A .1 Zypridina sp. Copepoda Unidentified species Calanoid sP - A and. B -@6 -17,-@@ 12 7 9 9.:.:. 59,.... 72. Euchaeta sp. 2' Candacia sp. Acartia sp. 1 6 1 2 Eucalanus sp. Centropagus 321 273 .58 26 50 Oncea sp. 2 2 2 1 Copilia sp. 3 4 Coryceaus sp. 4 9 1 3 2 Sapphirina sp. 2 3 7 9 2 4 Unidentified Cylcopoidid .1 Table 9c. Continued. Date: 9-83 Location Surface Oblique Surface Oblique Surface Obliqu Taxa Sampling Number P-21 P-22 P-23 P-24 P-25 P-26 Malacostraca Mysidacea sp. A Mysidacea sp. B Cumacea sp. A Isopoda sp. A Amphipoda sp. A 4 6 2 Decapoda/Shrimp mysis sp. 16 21 13 7 1 DecAp'oda/ Crab zoeae sp. 3 6 48 115 33 @20 Decapoda/Crab megalops sp. Mollusca Gastropoda Gastropod veliger larvae 36 16 57 94 137 86 Pteropoda Gresius acicula Uniden ified sp. A 2 2 Unidentified veliger capsules Cephalapoda (squid) 2 1 2 2 Chaetognatha Sagitta sp. A 11 5 77 187 22 74 Heteropoda Miscellanious Invertebrate Eggs 357 192" .405, .450. 600 6081:.@.@-' Chordata Urochordata Thaliacea (Salpa) Salpa sp. A .... 2 Vertebrata. 0 ste- fithyes -ic Fish larvae 1 1 2 2 Fish eggs "round and oval" 117 543 95 141 70 191 Fish eggs (Scarid) 2 14 #Individuals /cubic meter 9.06 10.82 10.17 11.22 9.86 11.48.. Total Species .19 16 19 17 17 17 Total Number ... 940 _1122 1055 1164.. Table 10. Species list of corals for Stations 1-4 in Bahia Laulau. List compiled from coral 20 meter band from the shore to 10 meter depth. FS Forereef Slope, RF R Reef Margin, Sta. @'..Stai:3.: _:.St Date: November 1982 FS RF RM FS RF .,:RM.. F S RF Class Anthozoa Order Scleractinia Suborder - Astrocoeniina ASTROCOENIIDAE Stylocoeniella armada (Ehrenberg, 1834) x Psammocora contigua (Esper, 1797) x P. digitata Milne-Edwards and Haime, 1851 P. superficialis Gardiner, 1898 x POCILLOPORIDAE Stylophora mordax (Dana, 1846) x x x Seriatopora crassa Quelch, 1886 x X. S. Dana, 1846 Yo c ankeli Scheer and Pillai, 1974 x@ P .damicornl_s@Linnaeus, 1758) X. x danae Verrill, 1864 X. @x P. elegans Dana, 1846 x "X' P .eydouxi Milne-Edwards and Haime, 1860 x x "P. Dana, 1846 x x P. setchelli Hoffmeister, 1929 x x x x x verrucosa (Ellis and Solander, 1786) x x x Table 10. Continued. Sta. 1 Sta. 2 Sta. 3 S FS RF RM FS RF RM FS RF AGROPORIDAE Acropora cerealis (Dana, 1846) x x x x x A. humilis (Dana, 1846) x x x A.. irregularis (Brook, 1892) x x A. monticulosa-(Bruggemann, 1879) x x @_X.'nasuta (Dana, 1846) x x x T. '@_cellata (Klunzinger, 1879) A. @_alifera (Lamarck, 1816) x A. *quelchi (Brook, 1893) x A. smithi (Brook, 1893) x A. squarrosa (Ehrenberg, 1834) x x x A. studeri (Brook, 1893) x T. surcul sa (Dana, 1846) x x x x x x A. tenuis ( ana, 1846) x x x x X. (Dana, 1846) x x x _X. '@`ariabilis (Klunzinger, 1879) x x x x x T. 7;W-ardiVerrill, 1901 x x T-corymbose sp. 1) x Astreopora myriophthalma (Lamarck, 1816) x x berryi Hoftmeister, 1925 x M. cf. M. caliculata (Dana, 1846) x ehr'-- Verrill, 1875 enbergii x x x x 7. 'JI'schneri Vaughan, 1918 x x x x 1@1. To-veolata (Dana, 1846) x x x x 2. T@o_ffmeisteri Wells, 1954 x X. x aniuscula (Dana, 1846) tuberculosa (Lamarck-, - -181.6), x -9. 7e_rri1liV-au9_han',' x x x x 7;;-errucosa (Lamarck, 1816) x Tf-oveolate sp. 1) x (tuberculate sp. 1) x TI. (tuberculate sp. 2) x x x Table 10. Continued. Sta.,I Sta. 2 Sta. 3 Stz FS RF RM FS' RF RM FS RF - Fungiina Suborder AGARICIIDAE Pavona divaricata (Lamarck, 1816) P. duerdeni Vaughan, 1907 x x x x P. maldivens_is (Gardiner, 1905) P. varians Verrill, 1864 x F. 7;@_enosa (Ehrenberg, 1834) x F. Te-ncrusting sp. 1) x Leptoseris mycetoseroides Wells, 1954 Fungia (Fungia) fungites (Linnaeus, 1758) x F @_ _r_____Fscutaria Lamarck, 1 . Pleu actis 816 Herpolitha limax (Houttuyn, 1772) PORITIDAE Goniopora tenuidens (Quelch, 1886) x Porites au:;t-raliensis Vaughan, .1918 x x 7x x x T _11chen Dana, IF46 P. T-utea Milne-Edwards and Haime, 1851 X. x 'X" X, 'XI' x x p . murrayen is Vaughan 1 1918 - x x superfi Gardiner ...... P. I.Ra 1898 (S naraea) convexa Verrill, 1864 X. x (Synaraea) iwayamaensis Eguchi, 1938 x x eopora sp. 1 Suborder - Faviina FAVIIDAE Favia favus (Forskal, 1775) x x x F. matthai Vaughan, 1918 x x x Table 10. Continued .... ...... Sta. 1 Sta. 2 Sta. 3 S FS RF RM FS RF RM FS RF F. pallida (Dana, 1846) x x x x x x F. rotumana (Gardiner, 1899) F. stelligera (Dana, 1846) x x x x Favites abdita (Ellis and Solander, 1786) x x F.. fi_exu`o`-s_a_TDana, 1846) x F. 7u-sselli (Wells, 1954) x Oulophyllia crispa (Lamarck, 1816) x x Goniastrea edwardsi Chevalier, 1971 x x G. pectinata (Ehrenberg, 1834) x G.'retiformis (Lamarck, 1816) x x x x x x x x Platygyra daedalea (Ellis and Solander, 1786) x x Platygyra Ej!2j Chavalier, 1975 x x x Lepto phrygia (Ellis and Solander, 1786) x x x x x Hydnophora microconos (Lamarck, 1816) x x Montastrea curta (F)ana, 1846) x x x x x x Diploastrea heliopora (Lamarck, 1816) x Leptastrea urpurea (Dana, 1846) @x x x L. transversa Klunzinger, 1879 x Gyphastrea chalcidicum (Forskal, 1775) x x OCULINIDAE Galaxea fascicularis (Linnaeus,. 1767). x MERULINIDAE cylindrica Milne-Edwards and x Haime, 1848 MUSSIDAE Acanthastrea echinata (Dana, 1846) x x x x @hlia corymbos (Forskal, 1775) (Ehrenberg, 1834) x x Table 10. Continued. Sta: 1 Sta. 2 Sta. 3 Stz FS RF RM FS RF RM FS RF PECTINIIDAE Echinophyllia aspera (Ellis and-Solanders 1786-) Order - Coenothecalia HELIOPORIDAE Heliopora coerulea (Pallas, 1766) x Class Hydrozoa Order Milleporina MILLEPORIDAE Mmillepora dichotoma Forskal, 1775 x M. latifolia Boschma, 1948 M. platyphylla Hemprich and Ehrenberg, 1834 x x tuberosa Boschma, 1966 Order - Stylasterina STYLASTERIDAE Stylaster profundiporus Broch,.1936' X. Total Species for Reef Zones 36 2 17 65 3 '.....30- Total Genera for Reef Zones 18 2 10 26 2 8 18 13 Total Species for Stations 36 !1' '49 Total Genera for Stations 18 28 19 Total Species for Reef Stations Combined 98 Total Tenera for Reef Stations Combined 34 Table 11. Coral size distribution, frequency, relative frequency.,-.. den sity, relative den strate coverage, relative percent..of substrate* cov*erag .e and importance value tive values) for Stations 2, 3, and 4 in Bahia Laulau. Species are listed in tance values. 'Size Distribution of Colony Diameters (cm) n y s w Date: November 1982 Stations 1 and.lA (Corals not quantitatively analyzed) Station 2 Reef-Flat Platform Zone Porites lutea 9 13.7 10.1 6-30 .30 60.00 .01 69. 2' Goniastrea retiformis 4 8.3 5.6 3-14, .20 40.00 .005 3 0. 7", Totals 13 12.8 8.5 3-30 .015 Station 2 Reef Margin Zone Pocillopora setchelli 10 9.9 4.8 3-18 .70 20.59 1.91 25.0( Gonia-strea retiformis 4 18.0 11.4 5-31 .40 11.76 .76 10.0( Montipora verrilli 3 21.7 6.4 17-29 '. 30 8.82 .57 7.5( Porites lutea ..3- 19.-7- 14..2.. 10-36 .20 5.88 .57 7.5 Acropora nasuta 4 13.5 7.0 5-21 .30 8.82 .76 10.0 A. surculosa 2 '16.5 16.3 5-28 .20 5.88 .38 5.0 K. :@7a_riabilis 3 8.7 0.6 8-9 .30 8.82 .57 7.5 Fori_t_e_s_FS_.T iwayamaensis 2 12.5 .9.2 6-19 .20 5.88 .38 5.0 on i oi@a-eh@enbergii- 1 28.0. ..7.. - .10 2.94 .19 2.5 Pocillopora verrucosa 2 7.0 1.4 6-8 .20 5.88 .38 5.0 Gal_ax_e_a_Ta"sZTi7_cularis 2 6.o 1.4 5-7 .20 5.88 .38 5.0 F-sammocora contigua 2 7.0 2.8 5-9 .10 2.94 .38 5.0 @av i a @RLI Li d 1 12.0 - - .10 2.94 .19 2.5 Montastrea curta 1 5.0 - - .10 2.94 .19 2.5 Totals 40 13.0 8.4 3-36 7.61 Table 11. Continued. bize Distribution of Colony Diameters (cm) n. y s Station 2 k'orereef Slope Zone Goniastrea retiformis 18 27.3 18.1 5-58 .53 18.79 2.28 30.00 Montipora ehrenbergii 6 51.0 33.8 14-99 .27 9.57 .76 10.00 M. verrilli 9 25.9 12.2 5-46 .47 16.67 1.14 15.00 Pocillopora setchelli 3 12.0 1.7 11-14 .20 7.09 .38 5.00 Acropora tenuis - 2 32.0 24.0 15-49 .13 4.61 .25 3.33 Montipora hoffmeisteri 3 17.7 10.6 8-29 .13 4.61 .38 5.00 Pocillopora verrucosa 2 23.5 4.9 20-27 13 4.61 .25 3.33 P. damicornis 2 18.0 14.1 8-28 .13 4.61 .25 3.33 Acropora cerealis 2 15.0 5.7 11-19 .13 4.61 .25 3.33 Leptoria phrygia 1 47.0 - - .07 2.48 .13 1.67 Acropora variabilis 3 7.3 2.1 5-9 .07 Z. 48 .38 5.00 A. surculosa 1 42.0 - - .07 2.48 .13 1.67 Favl-a-Ta-vus 2 14.0 8i5 8-20 .07 2.48 .25 3.33 Montipora elschneri 1 35.0 .07 2.48 .13 -1.67. Acanthastrea echinata 1 14.0 .07 2.48 .13 1.67 Porites -(S.) iwayamaensis 1 12.0 .07 2.48 .13 1.67 Montipora tuberculosa 1 9.0 .07 2.48.. o- 1.67 Acropora wardi 1 .@ 9,0- - ...07 2. 4&-: 1.67 Pocillopora d-anae 1--.54* .07 2. 48' 13 '24.4 7.61 Totals 60 @.','5 9.9". Station 3 R .eef-Flat Platform Zone (No corals encountered) Station 3 Reef Margin Zone Goniastrea retiformis 7 17.6 .12.7 5-34 .40 26.67 .06 29.17 Porites lutea 10 10.8.. 5..5 5-20 .50 33.33 09 41.67 Table 11. Continued. Size Distribution of colony Diameters (cm) n S w P. australiensis 3 10.3 3.1 1_13 .20 13.33 .03 12.50 Fa,v7ona venosa 1 18.0 - .10 6.67 .01 4.17 Acropora nassuta 1 12.0 - .10 6.67 .01 4.17 Acropora variabilis 1 7.0 - .10 6.67 .01 4.17 pallida 1 7.0 - - .10 6.67 .01 .4.17 Totals 24 12.75 8.28 5-34 .22 Station 3 Forereef Slope Zone (Weather prohibited quantitative analysis) Station 4 Reef-Flat Platform Zone AS12pora squarrosa 16 10.81 4.5 4-19 .80. 30.79 1.54 40.00 Montij2ora __-@_err_iffli 2 39.0 32.5 17.62 .10 3.85. .19 5.00 Acropora sp. 3 30.7 3.2 27.33 .20 7.69 .29 7.50 A. surculosa 3 20.7 8.5 11-27 .30 11.54 .29 7.50 T. Ta-riabilis .4 11.8 A.9 8-19 .20 7.69 ..39 10.00 Goniastrea retiformis 12.3. 6..1.. 7-19 i.20 7 ' 69 .29 7.150 2 16.0 5.7 12-20 .20 7.69 .19 5.00 7.69 .19 5.00 ,A@csror@a cerealis 2 10.5 0.7 10-11 ZO Porites murrayensis 1 30.0 - - 3.85 .10 2.50 Vo-ntastrea curta 2 11.5 7.8 6-17 .10 3.85 .19 5.00 V a-7v @i -a .10 3.85 .10 2.50 2.5. 0. - - 1 21. 0 - - .10 3.85 .10 2.50 Totals 40 16.1 10.7 4-62 3.86 Station 4 Reef Margin and Forereef Slope Zones Weather prohibited quantitative analysis) Table 12. Conspicuous macroinverteb rates collected or observed at B ahia Laulau, Saipan, Nov. 1982. Protozoa Foraminiferida (Foraminiferan) BAculogypsina sphaerulata (Parker and Jones) Site 2 and @3; sands Marginopora vertebralis Blainville Site.2,'and 3, sands',*.: Porifera @(Sponges) Cinchyra sp. Site la, reef flat; Z, reef flat; 4, -reef flat, Arthropoda Crustacea (Crustaceans) Coenobitidae (Land Hermit Crab) Coenobita sp. Site 2, beach Grap*sidae (Grapsid Crab) Grapsus tenuicrustatus (Herbst) Site la; 2, 4,.'high in'tertidal Ocy odide (Ghost crab) p .06ypode sp. Site 2 and 3, beach Xa4thidae, (Xanthid Crab) Carpilius maculatus (Linnaeus) Site 2, reef flat: Mollusca' Gastropoda (Snails) Pulmonata Ellobiidae Melampus flavus (Gmelin) Site 4, high intertid@il Prosobraiichia Patellidae (Limpets) Cellana radiata orientalis (Pilsbry) Site 2, high@ intertidal; 4, reef flat and high intertidal Trochidae (Trochids, Topshells) Tectus p@ramis (Born) Site-3, 30 ft. Trochus intextus Kiener Site 3, 30 ft. T. niloticus Linnaeus Site la, reef flat Turbinidae (Turban Shells) Astraea rho'dostoma (Lamarck) Site 1, 30 ft.; la, 20-30 ft. 2, 30 ft.; 3,, 30 ft. ; 4, 40-50 ft. Turbo argyrostomus Linnaeus Site 1, 30 ft. 3, 60 ft.; 4, 30-50 ft. T. petholatus Linnaeus Site 4, 30-50 ft. T. setosus Gmelin Site 2, reef flat Neritidae (Nerites) Nerita albicilla Linnaeus Site 2, high intertidal N. plicata Linnaeus Site 2, high intertidal; 4 high intertidal Table 12. Continued. Neritopsidae Neritopsis radula (linnaeus) Site 2, 30 ft. Littorinidae Littorina coccinea (Gmelin) Site 4, high inter:tidal E. -undulata Gray Site 2, high intertidal; 4, high intertidal Modulidae Modulus tectum (Gmelin) Site 1, 30 ft. Cerithiidae Cerithium moras Lamarck Site 2, high intertid'al C. mutatum Sowerby Site la, 20-30 ft.; 3, 60 ft. C. nodulosum Brugiere Site la, 20-30 ft.; 3,. reef flat -Rhinoclavis articulatus (Adam and Reeve) Site 1, 30 ft. R. aspera (Linnaeus) Site la, 20-30 ft. R. sinensis (Gmelin) Site 4, 30-50 ft.. Strombidae (Conchs) Lambus chiragra (Linnaeus) Site 1, 30 ft.; la, 20-30 ft 3, 3 0 ft. E.-Ta-mbi-S (Linnaeus) Site-3, 30 ft. Strombus dentatus Linnaeus Site 1, 30 ft. ; l a, 20-30 ft. S. luhuanus Linnaeus Site la, 20-30 ft'. S. mutabilis Swainson Site 1, 30 ft.; la, reef flat and 20-30 ft.; 39 reef flat Hipponicidae Hipponix conicus (Schumacher) Site 1, 30 ft.;. 3, 30 and 60 ft. 4, 30-50 ft. Cypraeidae (Cowries) Cypraea caputserpentis Linnaeus Site 1, 30 ft. C. depressa (Gray) Site 1, 30 ft. C. helvola Linnaeus Site 3, 20 ft. C. isabella Linnaeus Site la, 20-30 ft. C. Lynx Linnaeus Site la, reef flat C. moneta Linnaeus Site la, reef flat; 2, reef flat and ree'f front; 4, Tee f -f I -at Cypraea sp. (Juvenile) Site la, 20-30 ft. Tonnidae (Tonn shells) Tonna perdix '(Linnaeus) Site 2, beachwashed Cymatiidae Cymatium nicobaricum (Roeding) Site la, reef flat; 2, reef front Distorsic, anus (Linnaeus) Site la, reef flat Bursidae Bursa bufonia (Gmelin) Site 3, reef flat w Table 12. Continued. Muricidae Drupa (Roeding) Site 1., 30 ft. D. morum Roeding Site 4, reef f lat D.: ricinus (Linnaeus) Site 2, reef front; 4, reef flat and-30-50 ft. Drupella elata (Blainville) Site 3, 30 and 60 ft. D. ochro!it--oma (Blainville) Site 3, 30 ft. M. gra ------TDuclos) Site 4, reef flat nulata Morula biconica (Blainville) Site la, 20-30 ft. uva (Roeding) Site la, reef flat, 2. reef flat -ffuil-codru s (Wood) Site 1, 30 ft. ; la're f flat: pa funiculu e Thais armigera (Link) Site 1, 30 ft.; la, reef fla@t -3-@: @G, ft. Facio: larfidae Latirus nodatus (Gmelin) Site la, 20-30 ft. 30..ft"..' polygonusTGmelin) Site la, 20-30 ft. ; 2 reef 'flat. and reef afront Peristernia nassatula (Lamarck) Site la, reef flat*.- :2-:reef front'. Nassariidae Nassarius graniferus (Kiener) Site la, 20-30 ft., Vadidae Vasum turbinellus (Linnaeus) Site 1, 30 ft., .1 r a eef flat and 20-30 ft!; 2 'reef flat and reef frorit; 3, reef flat; 4, reef, flat Olividae (Olives) Oliva annulata (Gmelin) Site la, 20730 ft. Mitridae (Miters) Mitra cucumerina Lamarck Site 2, reef flat '@eremitarum Roeding Site 2, 30 ft. M . @ferruginea Lamarck (juvenile) Site la, reef flat -Mitr;@ Site 3, 60 ft. 'Reocancilla Papilio (Link) Site 2, 30 ft. Vexillum cadaverosum Reeve) Site la, 20-30 ft. V.- Toronatum (Helg-li-ng) Site la, 20-30 ft. V. exasperatum (Gmelin) Site . 2, 30 ft. modestum (Reeve) Site la, 20-30 ft. Conidae (Cones) Conus aulicus Linnaeus Site la, 20-30 ft. C. balteatus Sowerby Site la, reef flat; 3, 30 ft. C. coronatus Gmelin Site la, reef flat distans Hwass Site 1, 30 ft.; w. 30 ft.; 4, 40-50 ft. C. ebraeus Linnaeus Site 2, 30 ft. -C. i-burneus Hwass Site la, reef flat; 2, reef flat -C. flavidus Lamarck Site la, reef flat; 2, reef flat; 4, reef flat C. generalis Linnaeus Site 2, 30 ft. C. geographis Linnaeus Site la, 20-30 ft. .S. litoglyphus Hwass Site 1, 30 ft.; 2, 30 ft. C. lividus Hwass Site 3, reef flat and 30 ft. C. T@I@Ies Linnaeus Site la, 20-30 ft.; 2, reef front; 3, 30 ft. -E. ii=liaris Hwass Site la, reef flat and 20-30 ft. C. moreleti Grosse Site la, 20-30 ft. C. -M-U-S'lcus Hwass Site la, 20-30 ft. Table 12. Continued. C. planorbis Born Site la, 20-30 ft. C. pulicarius Hwass Site la, 20-30 ft. rattus Hwass Site la, reef flat C. si2onsalis Hwass Site 2, reef flat Z@. striatus Linnaeus Site la, 20-30 ft.; 2, 3 0@ft. C. tessulatus Born Site la, 20-30 ft. C. virgo Linnaeus Site la, 20-30 ft. Terebridae (Auger Shells) Tere bra subulata (Linnaeus) Site 2, 30 ft. Bivalvia (Clams) Arcidae Arca Site la, reef flat Barbatia Site 3, reef flat Limidae Lima annulata Lamarck Site 2, 30 ft.; 3, 30 ft. Chamidae Chama Site 2, 30 ft. Carditidae Cardita variegata Brufiere Site 3, 30 ft. Cardiidae Fulvia tenuicostata (lamarck) Site la; 20-30 ft. 3, 30-60 ft. 4, -@-0-50 ft. Tridacnidae (Giant Clams) Tridacna maxima (Roeding) Site 1, 30 ft. 2 reef flat;' 4,'. '30-50 ft. Veneridae Lioconcha Site la, 20-30 ft. Periglypta puerpera (Linnaeus) Site 4, 30-50 ft.: Echinodermata (Schinodermos) Holothuroidea Holothuriidae (Sea Cucumber) Actinopyga echinites (Jaeger) Site 2, reef flat A. mauritiana (Quoy and Gaimard) Site 2, reef flat Bohadschia argus Jaeger Site 2, reef flat; 4, reef flat Holothuria atra Jaeger Site 2, reef flat; 4 reef flat H. edulis Lesson Site 4, 30-50 ft. -ff. Te-ucospilota (Brandt) Site la, reef flat; 2 reef flat; 4 reef flat Stichopidae Stichopus cholorontus Brandt Site la, reef flat; 2 reef flat Thelenota ananas Site 1, 30-50 ft. Echinoidea (Sea Urchin) Diadematidae Echinothrix diadema Site 3, 30 ft. Table 12. Continued. Echinometridae Echinometra mathaei (Blainville) Site 2, -reef flat; 3, reef flat Asteroidea (Sea Stars) Acanthasteridae Acanthaster planci (Linnaeus) Site 1, 30-50 ft.; 3. reof.front Oreasteridae Culcita novaeguineae Muller and Troschel Site@.I, 30-50. :ft. 3, reef front Not Observed, @But Known To Be An Important Resource @Of:Bahia Laulau @Panularus sp. (Spiny Lobster, 3 species) Scyllaridae (Slipper Lobster, 8 genera) Table 13. Fish species observed at Bahia Laulau, Saipap, November 3-7, 1982. Asterisks indicate generally desirable food species. Chamorro: Site FAMILY/SPECIES Name 1 2 3 4 ACANTHURIDAE (Surgeonfishes) Acanthurus achilles Shaw x A. glaucoparieus Cuvier Hugupau x x x x A. lineatus (Linnaeus) Hiyuk x x x x x x x nigricaudus Dunker and Mohr x A. nigrofuscus (Forsskal) Hugupau x x x x olivaceus Bloch and Schneider Hugupau x x x Kittlitz x x x A. thompsoni (Fowler) x T. triostegus (Linnaeus) Kechu x x x Z@teiio`chaetus binotatus Randall x C. striatus (Quoy and Gaimard) Hugupau x x x x Naso brevirostris (Valenciennes) x x N_.hexacanthus (Bleeker) Guasa x x x *,N. lituratus (Bloch and Schneider)- Hanigun x x x x *.N. lopezi Herre x unicornis (Forsskal) Tataga x Paracanthurus hepatus (Linnaeus) x Zebrasoma flavescens (Bennett) Ababang x x APOGONIDAE (Cardinalfishes) Apogon novemfasciatus Cuvier Lansi x x:: x A. sp.. Lan si X.. .Cheilodepterus macrodon (Lacepede) Lansi x AULOSTOMIDAE (Trumpetfishes) Aulostomus chinensis (Linnaeus) Badyak X@ BALISTIDAE (Triggerfishes) Balistipus undulatus (Park) x X x x Melichthys vidua (-Solander) Pulunun x x: x x Odonus niger (Ruppell) Pulunun x R-hinecan-thus aculeatus (Linnaeus) Pulunun x. x R. echarpe @(LacepedeT x 97ufffa-men bursa (Bloch and Schneider) Pulunun x x x S. chrysopterus (Bloch and Schneider) Pulunun x x x x BLENNIIDAE (Blennies) Exallias brevis (Kner) Maching x Meiacanthus atrodorsalis .(Gunther) Maching x x x Plagiotremus tapeinosoma (Bleeker) Maching x Salarias fasciatus TB-loch) Maching x Table 13. Continued. Chamorro Site FAMILY/ SPECIES Name 2 3 4 Blenniid sp. 1 Maching x Blenniid sp. 2 Maching x CAESIONIDAE (Fusiliers) Caesio caerulaureus Lacepede Bonita X X x x C. tile Cuvier and Valenciennes Bonita X* C. xanthonothus Bleeker Bonita x x Pterocaesio chrysozona Cuvier Bonita x @c x CARANGIDAE (Jacks, Pompanos) * Caranx melampygus Cuvier Ee, Taraki"to. -x x * C. -sexfasciatus Quoy & Gaimard Mamulon x CHARCHARHINIDAE (Requiem Sharks) Charcharhinus melanopterus Haluu x CHAETODONTIDAE (Butterflyfishes) Chaetodon- auriga Forsskal Ababang x x x C. bennetti Cuvier Ababang x citrinellis Cuvier Ababang x: x x C. ephippium Cuvier Ababang x x x lineolatus Cuvier Ababang : x lunula Macepede) Ababang X,:. x x x C. mertensli Cuvier Ababang x x ornatissimus Cuvier Ababang xj: X x x C. punctat6fasciatus Cuvier Ababang X. x x x C. quadrimaculatus Gray Ababang x x x reticulatus Cuvier Ababang X. x x x C. trifasciatus Park Ababang x x C. ulietensis Cuvier Ababang x x x unimaculatus Bloch Ababang x X x Forcipiger flavissimus Jordan and McGregor Ababang x x x F. longirostris (Broussonet) Ababang X- Megaprotodon trifascialis (Quoy and Gaimard)Ababang x x x x CIRRHITIDAE (Hawkfishes) Cirrhitichthys falco Randall x x Neocirrhites armatus Castelnau x x Paracirrhites arcaFus (Cuvier) x x x x P. forsteri (Bloch and Schneider) X, x x x DASYATIDAE (Stingrays) Taeniura melanospilos Bleeker Hafula x Table 13. Continued Chamorro Site FAMILY/SPECIES Name 1 2 3 4 GOBIIDAE (Gobies) Amblyeleotris steinitzi (Klausewitz) Maching. x x Nemateleotris magnifica. Fowler Maching x x Pogonoculius zebra Fowler Maching x x Ptereleotris evides (Jordan and Hubbs) Maching x Valencienna uellaris (Tomiyama) Maching x V. strigatus (Broussonet) Maching x x x HAEM"ULIDAE (Sweetlips) Plectorhynchus orientalis (Bloch) Hamala @x 'HEMIRAMPHIDAE (Halfbeaks) Hemiramphus dussumieri (Valenciennes) Anko, Hankut x HOLOCENTRIDAE (Squirrelfishes) '*.Adioryx caudimaculatus (Ruppell) Suksuk x A. ruber (Forsska-lT- Suksuk x A. spinnifer (Forsskal) Sesiok x x Tlamm-eo opercularis (Valenciennes) Chalak X. F. sammara (Forsskal) Chalak X* x T4yrpristis berndti Jordan and Evermann Sagsag x x M. murdian (Forsskal) Sagsag x x .LABRIDAE .(Wrasses) Anampses caeruleopunctatus Ruppell Aaga x x x x A. meleagrides Valenciennes Aaga X, .. A. twistii (Bleeker) Aaga X, x Bodianus akillaris (Bennett) X@ Cheilinus celibicus. Bleeker Aaga X: C. unifasciatus Streets Aaga x X x x Z@. trilobatus Eacepede Lalatsa-Mamati x x x C. undulatus Ruppell Tanguisun ThJ-lio inermis (Forsskal) Aaga x TIT-r-hilabrus sp. Aaga x x Coris aygula Lacepede Aaga x x C. gaimard:(Quoy and Gaimard) Aaga x x -Epibulus insidiator (Pallas) Aaga x x x Gomphosus varius Lacepede Aaga x x x x Halichoeres biocellatus:. Schultz Aaga x x H. hortulanus (La-cepe8e) Aaga x X x x ff. margaritaceus (Valenciennes) Aaga x x x x H. marginatus Ruppell Aaga x x H. scapularis (Bennett) Aaga x R. trimaculatus (Quoy and Ga'imard) Aaga x x Hemigymnus fasciatus (Bloch) Aaga x x x x Table 13. Continued. Chamorro Site FAMILY/SPECIES Name 1. 2 3 4 H. melapterus (Bloch) Aaga X Hologymnosus doliatus (Lacepede) Aaga. x x x Labrichthys unilineatus (Guichenot) Aaga X. Labroides dimidiatus (Valenciennes) Aaga X% X. x Macropharyngodon meleagris (Valenciennes) Aaga X: x x Novaculichthys taeniourus (Lacepede) Aaga x x Pseudocheilinus evanidus Aaga, x P. hexataenia, (Bleeker@- Aaga x ,x x x is bandanensis (Bleeker) Aaga X x x Stethojul Thalassoma, fuscum (Lacepede) Aaga X; ,x x T. lutescens (Lay and Bennett) Aaga X, '.X x x x x T. quinguevittatum (Lay and Bennett) Aaga LETHRINIDAE (Emperors) Gnathodentex aureolineatus (Lacepede) Salagai x; k X. Lethrinus:hara-k-TF-orsskal) Mafute :X x X:, L. semicinctus Valenciennes Mafute X. Ponotaxis grandoculis (Forsskal) Matanhagon x :x x x LUTJANIDAE, (Snappers) Aphareus furcatus (Lacepede) x x Aprion virescens Valenciennes X.: Lutjanus bQhar Forsskal) Tagafi X: x Kakaka x x L. fulvus@ (Blo h and Schneider) tusi (Cuvier and Valenciennes) xl'.L. L. russelli 1. @Bleeker) x !@acolor niger (Forsskal) X x x MALACANTHIli.AE (False Whitings) Malacanthus. brevirostris Guichenot X M. latovTttatus (Lacep e) x MONACANTHIPAE (Filefishes) Cantherhines pardalis, (Ruppell) x x x Oxymonacanthus longirostris (Bloch and Schneider) Hagonfa Ha x Pervagor melanocephalus (Bleeker) x x MUGILOIDIDAE (Sand Perches) Parapercis cephalopunctata (Seale) x x x x P. clathrata, Ogilby x x x Table 13. Continued Chamorro Site FAMILY/SPECIES Name 1 2 3 4 MULLIDAE (Goatfishes) Mulloides flavolineatus (Lacepede) Tiao or x x M. vanicolensis (Vale-nciennes) Salmonete' x Parupeneus barberinus (Lacepede) Salmoniti x P. bifasciatus (LaE-e-pede) Salmoniti x x x x -P .chryseredros (Lacepede) Amariyu x P. pleurostigma (Bennett) x x poryphyreus Jenkins x P. trifasciatus (Lacepede) Salmoniti x x x x MURAENIDAE (Moray Eels) Lycodontis sp. Titugi x NEMIPTERIDAE (Monacle Breams) **Scolopsis cancellatus (Cuvier) Sihig x OPICHTHIDAE (Snake Eels) Myrichthys colubrinus. (Boddaert) Hagman-Lisado x P,EMPHERIDAE (Sweepers) Pempheris oualensis Cuvier x x POMACANTHIDAE (Angelfishes) Apolemichth trimaculatus (Cuvier) Ababang@ x "n+slavissimus (Cuvi Ababang- x CentropyLge er) x x C. hearaldi Woods and Schultz Ababang x C. shepardi Randall and Yasuda Ababang x x x Py oplites diacanthus (Boddaert) Ababa-ng x x Pomacanthus imperiit-or (Bloch) Ababang x POMACENTRIDAE (Damselfishes) Abudefduf septemfasciatus (Cuvier) Doddo X: x A. vaigiensis (Quoy and Gaimard) Fohmo X, x Amblyglyphidodon aureus (Cuvier) Fohmo x x x x Amphiprioii -clarkii -FB-ennett) Fohmo x x Chromis acares Randall and Swerdloff Fohmo x x C. agilis Smith Fohmo x C. caerulea (Cuvier) Fohmo x margaritifer Fowler Fohmo x -----TBleeker) Fohmo x x C. xanthura x Chrysiptera biocellatus (Quoy and Gaimard) Fohmo x x C. glaucus (CuvierT- Fohmo x Table 13. Continued Chamorro Site FAMILY/SPECIES Name 1 2 3 4 C. leucopomus (Lesson) Foh'Mo x x: x T -ra -ce and Schultz) FAmo X, x y, (Woods Dascyllus aruanus (Linnaeus) Fohmo X. D. reticulatus (Richardson) Fohmo X. D. trimaculatus (Ruppell) Fohmo xw Plectroglyphidodon dickii (Lienard) Fohmo X x x P. imperipennis (Valliant and Sauvage) Fohmo x P. johnstonianus Fowler and Ball Fohmo x x P. lacrymatus (Quoy and Gaimard) Fohmo x x x Pomacentrus vaiuli Jordan and Seale Fohmo x x Pomachromis guamensis Allen and Larson Fohmo X, -9-tegastes fasciolatus (Ogilby) Fohmo x: :K x x S CARID AE (Parr'otfishes) Cetoscarus bicolor (Ruppell) @x Scarus brevif@ilis Gunther) x frenatus. Lacepede Lagua x f rontalis. Valenciennes Lagua gibbu's Rupp'ell Lagua @K x S. oviceps@ Valenciennes Lagua x S. psittacus Forsskal Palagsi x x x S. rubroviolaceus (Bleeker) Lag'ua x x x S. @chlegeli: M-leeker) Lagua x x x x sordidus'. Forsskal. Lagua. X. x x x S. tricolor Bleeker Lagua X@ sp. Lagua ic v S. sp. Lagua. x SERRANIDAE. (Groupers) *Cephalopholis urodelus (Bloch & Schneider) Gadao x x *C. sonneratus (Cuvier) Gadao x Epinephelus merra Bloch Gadao x Plectropomus leopardus (Lacepede) Gadao x Variola I FB-I e-e k-e-rT x SIGANIDAE (Rabbitfishes) Siganus argenteus (Quoy and Gaimard) Hiting x x ALnus (Linnaeus) Seyun x x SYGNATHIDAE (Pipefishes) Corythoichthys intestinalis (Ramsey) Hilitsi-Tasi x SYNODONTIDAE (Lizardfishes) Saurida gracilis (Quoy and Gaimard) PiPiPU x x Synodus variegatus (Lacepede) Pipipu x Table 13. Continued Chamorro Site FAMILY/SPECIES. Name 1 2 3 4 TETRAODONTIDAE (Smooth Puffers) Canthigaster amboinensis (Bleeker) Botati x x C. bennetti (BleekerT- Botati x C. solandri (Richardson) Botati x x x @@-alentini (Bleeker) Botati x ZANCLIDAE (Moorish Idols) Zanclu's cornutus (Linnaeus) Ababang: x x x x :.TOTAL NO. FAMILIES 35 23 31 28 19 TOTAL NO. SPECIES 200 107 130 124 7@ *TOTAL NO. FOOD SPECIES 75 35 51 38 27 2 and 3,: Bahia Table 14. Fish species observed on the reef flat at Sites Laulau, Saipan, November 3-7, 1982. FAMILY/SPECIES CHAMORRO NAME ACANTHURIDAE (Surgeonfishes) Acanthurus nigrofuscus Hugupau A. triostegus Kechu APOGONIDAE (Cardinalfishes) Apogon novemfasciatus Lansi BALISTIDAE (Triggerfishes) @.Rhinecanthus aculeatus Puluniin.: BLENNIIDAE (Blennies) Balarias fasciatus Maching.:- CARANGIDAE (Jacks, Pompa-nos) Caranx melampygus Ee; Tarakito CHARCHARHINIDAE (Requiem Sharks) ',Charcharhinus melanopterus Haluu. CHAETODONTIDAE (Butterfly fishes) Chaetodon auriga Ababang@ C.: citrinellis Abagang C. . lunula Ababan.g.. Lo nnat HOLOCENTRIDAE (Squirrelfishes) A!dioryx spinnifer Sesiok Flammeo opercularis Chalak LA,BRIDAE (Wrasses) Cheilinus trilobatus Lalatsa-Mamati Cheilio inermis Aaga Halichoeres hortulanus Aaga H. marginatus Aaga H. trimaculatus Aaga Stethojulis bandanensis Aaga LETHRINIDAE (Emperors) Lethrinus harak M afute Table 14. Continued. FAMILY/SPECIES CHAMORRO NAME LUTJANIDAE (Snappers) Lutjanus fulvus Ka@kaka MULLIDAE (Goatfishes) Miulliodes flavolineatus Tiao, Salmonete Ta-rupeneus trifasciatus Salmoniti, Acho P. poryphyreus MURAENIDAE (Moray Eels) Lycodontis sp. Titugi OPICHTHIDAE (Snake Eels) Myrichthys colubrinus Hagman-Lisado POMACANTHIDAE (Angelfishes) Pomacanthus imperator Ababang POMACENTRIDAE (Damselfishes) @.Abudefduf septemfasciatus Fohmo, Doddo. @Chrysiptera biocellatus Fohmo C.. leucopomus Fohmo, C. glaucus Foh.mo Pomacentrus vauili Fohmo SCARIDAE (Parrotfishes) Scarus oviceps Lagu*a S. psittacus Palagsi -9. schlegeli Lagua, -9. sordidus Lagua SERRANIDAE .(Groupers) .Cephalopholis sonneratus Gadao SIGANIDAE (Rabbitfishes) Siganus s2ftius Manahak, Seyun SYGN.ATHIDAE (Pipefishes) Corythoichthys intestinalis Hilitsi-Tasi Table 14. Continued. FAMILY/SPECIES CHAMORROVAMES SYNODONTIDAE (Lizardfishes) .'Saurida gracilis Pipipu TETRAODONTIDAE (Smooth Puffers) Canthigaster bennetti Botati i C. solandri Botat ZANCLIDAE (Moorish Idols) G Zanclus cornutus Ababahg up alao Table 15. Juvenile fishes observed during reconnaissance and transect dives at Bahia Laulau, Saipan, November 3 - 7, 1982. Numbers are based on transect dives only. RF = Reef Flat; RS = Forereef Slope; Trophic groups: C = Carnivore, H: Herbivore, 0 Omnivore. SPECIES TOTAL RF# RS# TROPHIC NUMBER GROUP Acanthuridae (Surgeonfishes) Acanthurus glaucoparieus 1 1 H Acanthurus nigrofuscus 1 1 H Wcanthurus thompsoni 1 1 H Acanthurus triostegus 1 H Ctenochaetus striatus 1 1 H Ctenochaetus binotatus 1 1 H Naso lituratus 3 3 H Apogonidae (Cardinalfishes) Apogon novemfasciatus .4 4 C Apogon sp 6 6 C Blenniidae (Blennies) Meiacanthus atrodorsalis 1 1 C Plagiotremus tapeinosoma I I C Labridae@ (Wrasses) Cori aygula 1 C -a-0-Mphosus varius 3 3 C Halichoeres hortulanus 1 1 C Halichoeres marginatus 3 3 C Falichoeres trimaculatu-s 3 3 C Labrichthys unilineatus 2 ..2 C Stethojulis bandanensis 3 3 C Lutjanidae (Snappers) Lutjanus russelli 1 1 C Pomacanthidae (Angelfishes) Pomacanthus imperator H Table 15. Continued RF# RS# SPECIES TOTAL TROPHIC NUMBER :GROUP Pomacentridae (Damselfishes) Chrysiptera. briocellatus 21 21 H Chrysiptera leucopomus 5 1 @4 H Chrysiptera traceyi 1 H H Plectroglyphidodon lacrVmatus 4 :4. Pomacentrus vaiuli 5 :5 0 Stegastes fasciolatus 1 H Scaridae (Parrotfishes) q Scarus schlegeli 1 1. H Scarus sordidus 5 2 3: H Scarus sp 1, 1 1. H Scarus sp 2 1 1. H Synodontidae .(Lizardfishes) Salarida gracilis 2 1 C S@ TOTAL NUMBER PERCENT OFTOTAL Number -of @Jndividuals 86 Number of -,Species 31 Number of. Families 9 Number of' Herbivores 17 55 Number. of Carnivores 13 42, Number of Omnivores 1 3 Table 16. Fish densities calculated for different depths and general reef zones from line transect data compiled at Sites 2 and 3, Bahia Laulau, Saipan, November 3-7, 1982. Transect Study Site Depth (m) Length (m) #spp/20 m? #indiv/20 m 2. w REEF FLAT: Site 2 1 50 4.8 13.6 Site 3 1 100 3.2 5.6 Sites 2 and 3 1 150 3.7 8.3 FOREREEF SLOPE: Site 2 9 100 6.1 11.8 Site 3 9 100 9.5 22.8 Sites 2 and 3 9 200 7.8 17.3 Site 2 18 100 5.4 11.4 Site 3 18 100 9.4 27.6 Sites 2 and 3 18 200 7.6 19.5 Site 2 9 and 18 200 5.8 11.6 Site 3 9 and 18 200 9.4 25.@ Sites 2 and 3 9 and 18 400 7.7 18.4 Table 17. Fish densities calculated for different substrate categories from line transect data compiled at Sites 2 and 3, Bahia ''Laulau, Saipan, November 3-7, 1982. Transect: STUDY SITE Depth (m) Length (m) #spp/20 m'. Andiv/20 m' REEF FLAT: (Sites 2 and 3) Shallows: 0.3 70 :1.3 1.6 Depressions 0.3, 1 80 :5,9 14.0 FOREREEF:SLOPE: (Site 2) Sand/Rubble. 9 30 :2.:O@ 2.0 Sand/Rubble 18 20 5.1 1.5 2.0 Sand/Rubbl6' 9&18 50 Sand/Rubble with Rocks or Coral 9 40 11.0 Sand/Ru*bble with Rocks: or. Coral 18 50 A.* 5 6.2 Sand/Rubble with Rocks:or Coral 9&18 90 :4. 7'. 8.3 Coral 9 30 23.7 Coral 18 30 -10.3' 25.3 Coral 9&18 60 .11.0: 24.5 APPENDi,x PLATES 4TnPsse GAPM aT44TT qqTm AL-P UrE20 rIGA L- Sem STL;L @4Ts oam T-e-Fqua-4od eqq qL- u-r BuppoT pam-meas ux)x maTAZ A4TT-FDPJ 0= @LR aOJ @TFS T'E?T'4ua'4od aqq: Ta4TS '4P UmOP BuTNOOT ueui6pH uc--4urid mi maTA '-T ko. yn@ tap X*_ qr One of the numerous sand channels which run perpendicular out frcm Site 1. The depth here is approximately 60 feet. 7, @7 4b 4. The seaward slope just offshore of Site 1. Three Acanthaster planci can be seen feeding on the coral in the foreground. Depth here is approximately 30 feet. t qp -4--'aJ SZ JO q4dGP e 412 PunOJ SuO-F-4L'mOJ T-GaOO T-eO-FcVL `9 14@ 17 T- a_T olqs aqq jBUOTL- Saqot--@ PUPS -D@Aq 0-4 qpTg:.@Jaaa aq4 Ssolov tr-I-Tou BUT3(00-[ PT -a-4 TS Site 2 looking southeast across Bahia Laulau. The cut used for boat and diver access is located between the larger rocks in the left side of the photo. 7, 1 7 Typical coral coverage at Site 2 taken at a depth of 30 feet. 71i@ 10, 4r* B 9.L Site 3 looking sou@heast across ahia Laulau.. Chamorro Village restaurant can be seen on the-top of-thd cliff to the right. 1.0. Typical underwater view taken at a depth of 40 feet at Site 3. 11-. Looking south across Bahia Laulau to Site 4. The quarry below the airport is just to the right of SiteA. Pr@ 7;@ 7-A z @0. 12. Underwater view of Site 4 taken at a depth of approximately 50 feet. NOAA COASTAL SERVICES CTR LIBRARY I ;- 3 6668 14111047 0 1 1 1 1 I I I I I I I I I I I I I I