[Federal Register Volume 81, Number 153 (Tuesday, August 9, 2016)]
[Notices]
[Pages 52614-52635]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-18815]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XE74
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Waterfront Improvement Projects
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments.
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SUMMARY: NMFS has received a request from the U.S. Department of the
Navy (Navy) for authorization to take marine mammals incidental to
construction activities as part of waterfront improvement projects at
several berths. Pursuant to the Marine Mammal Protection Act (MMPA),
NMFS is requesting public comment on its proposal to issue an
incidental harassment authorization (IHA) to the Navy to incidentally
take marine mammals, by Level B harassment only, during the specified
activity at Portsmouth Naval Shipyard (the Shipyard) in Kittery, Maine.
DATES: Comments and information must be received no later than
September 8, 2016.
ADDRESSES: Comments on the application should be addressed to Jolie
Harrison, Chief, Permits and Conservation Division, Office of Protected
Resources, National Marine Fisheries Service. Physical comments should
be sent to 1315 East-West Highway, Silver Spring, MD 20910, and
electronic comments should be sent to [email protected].
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments received electronically, including
all attachments, must not exceed a 25-megabyte file size. Attachments
to
[[Page 52615]]
electronic comments will be accepted in Microsoft Word or Excel or
Adobe PDF file formats only. All comments received are a part of the
public record and will generally be posted to the Internet at http://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm without
change. All personal identifying information (e.g., name, address)
voluntarily submitted by the commenter may be publicly accessible. Do
not submit confidential business information or otherwise sensitive or
protected information.
FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
An electronic copy of the Navy's application and supporting
documents, as well as a list of the references cited in this document,
may be obtained by visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing
these documents, please call the contact listed above (see FOR FURTHER
INFORMATION CONTACT).
National Environmental Policy Act
The Navy has prepared a draft Environmental Assessment (Waterfront
Improvement Projects, Portsmouth Naval Shipyard, Kittery, ME) in
accordance with the National Environmental Policy Act (NEPA) and the
regulations published by the Council on Environmental Quality. NMFS
will independently evaluate the Environmental Assessment (EA) and
determine whether or not to adopt it. We may prepare a separate NEPA
analysis and incorporate relevant portions of Navy's EA by reference.
Information in the Navy's application, EA, and this notice collectively
provide the environmental information related to proposed issuance of
this IHA for public review and comment. These documents will be posted
at the foregoing Web site. We will review all comments submitted in
response to this notice as we complete the NEPA process, including a
decision of whether to sign a Finding of No Significant Impact (FONSI),
prior to a final decision on the incidental take authorization request.
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
as ``an impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.''
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: Any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment].
Summary of Request
On Wednesday February 17, 2016, NMFS received an application from
the Navy for the taking of marine mammals incidental to Waterfront
Improvement Projects. NMFS determined that the application was adequate
and complete on April 1, 2016. The Navy is proposing to restore and
modernize waterfront infrastructure associated with Dry Docks 1 and 3
at the Shipyard in Kittery, York County, Maine. The proposed action
would include two waterfront improvement projects, structural repairs
to Berths 11, 12, and 13, and replacement of the Dry Dock 3 caisson.
The waterfront improvement projects would be constructed between
October 2016 and October 2022, with in-water work expected to begin no
earlier than January 2017. The requested IHA would run from January 1,
2017 through December 31, 2017.
The use of vibratory and impact pile driving for pile installation
and removal as well as drilling is expected to produce underwater sound
at levels that have the potential to result in behavioral harassment of
marine mammals. The term ``pile driving'' throughout this document
shall include vibratory driving, impact pile driving, vibratory pile
extraction as well as pile drilling unless unless specified otherwise.
Species with the potential to be present during the project timeframe
include harbor porpoise (Phocoena phocoena), gray seal (Halichoerus
grypus), harbor seal (Phoca vitulina), hooded seal (Crystphora
cristata) and harp seal (Pagophilus groenlandicus).
Description of the Specified Activity
Overview
The U.S. Department of the Navy (Navy) is proposing to restore and
modernize waterfront infrastructure associated with Dry Docks 1 and 3
at the Shipyard in Kittery, York County, Maine (See Figure 1-1 in the
Application). The proposed action would include two waterfront
improvement projects, structural repairs to Berths 11, 12, and 13 and
replacement of the Dry Dock 3 caisson.
The purpose of the proposed action is to modernize and maximize dry
dock capabilities for performing current and future missions
efficiently and with maximum flexibility. The need for the proposed
action is to correct deficiencies associated with the pier structure at
Berths 11, 12, and 13 and the Dry Dock 3 caisson and concrete seats and
ensure that the Shipyard can continue to support its primary mission to
service, maintain, and overhaul submarines. By supporting the
Shipyard's mission, the proposed action would assist in meeting the
larger need for the Navy to provide capabilities for training and
equipping combat-capable naval forces ready to deploy worldwide.
Proposed activities included as part of the Waterfront Improvement
Projects with potential to affect marine mammals within the waterways
adjacent to the Shipyard include vibratory and impact pile driving as
well as pile drilling operations in the project area.
Dates and Duration
In-water construction associated with the Proposed Action would
occur in phases over a six-year construction period. In-water
construction is scheduled to begin in January 2017 and be completed by
October 2022. This application is for the first year of in-water
construction, from January 1, 2017 to December 31, 2017. No seasonal
limitations would be imposed on the construction timeline. Construction
schedules for in-water work at Berth 11 are under development and
subject to change based on operational
[[Page 52616]]
requirements. Therefore, this IHA application covers all in-water
construction planned for Berth 11 structural repairs. The Navy intends
to apply for sequential IHAs to cover each of the subsequent years of
construction.
Table 1 summarizes the in-water construction activities including
pile extraction, driving, and drilling, scheduled to take place during
the timeframe covered by this IHA application. Note that pile driving
days are not necessarily consecutive. Also note that certain activities
may occur at the same time, decreasing the total number of pile driving
days, thus making the total days described below a conservative
estimate. Total driving time will be approximately 72 days which
includes the installation of 327 piles and removal of 141 piles.
Table 1--Activity Summary for Year 1 of the Berths 11, 12, and 13 Structural Repairs
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Number of Number of
Activity/method Timing Number of days Pile type piles piles
installed extracted
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Extract timber piles/ January 2017 to \1\ 10 15-inch timber .............. 77
vibratory hammer. December 2017. pile.
Install temporary sister January 2017 to \2\ 16 14-inch steel H- 64 ..............
piles for trestle system/ December 2017. type.
vibratory hammer.
Install permanent king piles January 2017 to 10 36-inch steel H- 94 ..............
for bulkhead/auger drilling. December 2017. type piles.
Install steel sheet-pile January 2017 to 6 24-inch steel 112 ..............
bulkhead/vibratory hammer December 2017. sheet-piles.
(sheet piles and sheet pile
returns).
Install permanent sister January 2017 to \2\ 13 14-inch steel H- 50 ..............
piles/impact hammer. December 2017. type.
Install timber dolphin....... January 2017 to \1\ 1 15-inch timber 7 ..............
January 2017. piles.
Extract temporary sister January 2017 to \2\ 16 14-inch steel H- .............. 64
piles for trestle system/ December 2017. type.
vibratory hammer.
---------------- -------------------------------
Totals................... ................ 72 ............... 327 141
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\1\ Estimate based on assumption of 30 minutes to drive each pile and 30-minute transition and set up time,
resulting in one pile per hour and eight piles per day (ICF Jones and Strokes and Illingworth and Rodkin, Inc.
2012).
\2\ Estimate based on assumption of a one-hour transition and set up time, resulting in one pile per two hours
and four piles per day (ICF Jones and Strokes and Illingworth and Rodkin, Inc. 2012).
Note: The Navy provided the following information in response to technical questions:
King Piles--estimate of 10 per day.
Sheet piles--estimate of 20 per day, based on 20 piles in 8 hours (i.e., one day) because they will be installed
two at a time.
Specified Geographic Region
The Shipyard is located along the Piscataqua River in Kittery,
Maine. The Shipyard occupies the whole of Seavey Island, encompassing
278 acres on what were originally five separate islands (Seavey,
Pumpkin, Dennett's, Clarks, and Jamaica). Over the past 200 years, as a
result of expansion from land-making activity, four of these islands
(Seavey, Pumpkin, Dennett's, and Jamaica) were consolidated into one
large island, which kept the name Seavey Island. Clarks Island is now
attached to Seavey Island by a causeway. Seavey Island is located in
the lower Piscataqua River approximately 547 yards from its southwest
bank, 219 yards from its north bank, and approximately 2.5 miles from
the mouth of the river.
Detailed Description of Activities
The Navy's application focuses primarily on the in-water
construction activities that will occur during the first year of
construction, including completion of the king pile and concrete
shutter panel bulkhead at Berth 11. Additional applications will be
submitted for each subsequent year of in-water construction at Berths
11, 12, and 13 as well as for the replacement of the Dry Dock 3
caisson.
Pile Driving Operations
Piles of differing sizes will be utilized during construction
activities including 25-inch steel sheet piles driven by vibratory
hammer at Berth 11; 14-inch steel H-type piles driven using impact
hammer at Berth 11; 15-inch timber piles installed via vibratory hammer
to reconstruct dolphins at the corner of Berth 11; and 36-inch steel H-
type piles at Berth 11. Additionally 14-inch steel H-type piles would
be used to align and construct the trestle that would be extracted
using vibratory hammer at Berth 11 and 15-inch timber fender piles,
which would be extracted using a vibratory hammer at Berth 11 and the
timber dolphin at the corners of Berths 11 and 12.
The number of piles that can be driven per day varies for different
project elements and is subject to change based on site conditions at
the time. At the beginning of the in-water work, existing timber piles
would be removed from the berth faces and the timber dolphin at the
western end of the berth, and the contractor either would construct a
temporary construction trestle or place a jack-up barge alongside the
berths to provide additional construction workspace. Pile driving and
extraction would also be needed to construct and disassemble the
temporary construction trestle if the construction contractor selects
this method over use of a jack-up barge, which would require no pile
driving. The trestle system has been included in this analysis in order
to model a conservative, worst-case scenario. If a jack-up barge is
used instead of a trestle system, less pile driving will be needed,
resulting in fewer marine mammal takes than predicted in this
application.
For the proposed king pile and concrete shutter panel bulkhead (see
Figures 2-1 and 2-2 in Application), the contractor would likely create
templates and work in increments along the berth from the trestle or
jack-up barge. For example, an approximately 50-foot-long template
would allow installation of about 10 king piles and 20 sheet piles
(along segments of the berths where sheet piles would be installed).
The work would consist of setting a template (including temporary piles
and horizontal members), which might take one or two days. Then the
contractor
[[Page 52617]]
would drill the rock sockets, which could take about one day per
socket. King piles would be regularly spaced along the berths and
grouted into sockets drilled into the bedrock (i.e., ``rock-
socketed'').
The concrete shutter panels would then be installed in stacks
between the king piles along most of the length of Berth 11.
Installation of the concrete piles is not included in the noise
analysis because no pile driving would be required. Along an
approximately 16-foot section at the eastern end of Berth 11A and an
additional 101 feet between Berths 11A and 11B, the depth to bedrock is
greater, thus allowing a conventional sheet-pile bulkhead to be
constructed. The steel sheet-piles would be driven to bedrock using a
vibratory hammer. Sheet piles installed with a vibratory hammer also
would be used to construct ``returns,'' which would be shorter
bulkheads connecting the new bulkheads to the existing bulkhead under
the pier. Installation of the sheeting with a vibratory hammer is
estimated to take less than one hour per pair of sheets. The contractor
would probably install two sheets at a time and so the time required
install the sheeting (10 pairs = 20 sheets) using vibratory hammers
would only be about 8 hours per 10 pairs of sheets. Time requirements
for all other pile types were estimated based on information compiled
from ICF Jones and Strokes and Illingworth and Rodkin, Inc. (2012).
If sufficient construction funds are available, the Navy may
install a king pile and concrete shutter panel bulkhead at Berth 11C as
part of Phase 1. The bulkhead would extend from the western end of
Berth 11B to the southern end of Berth 12. The in-water construction
process would be the same as the process described above. The analysis
in this application includes construction at Berth 11C. Once the Berth
11 bulkheads are complete, the timber dolphins at the western end of
the berth would be replaced with a similar dolphin constructed of
approximately seven piles.
Additional in-water work would be required to install steel H-type
sister piles at the location of the inboard portal crane rail beam at
Berth 11, including Berth 11C. The sister piles would provide
additional support for the portal crane rail system and restore its
load-bearing capacity. The sister piles would be driven into the
bedrock below the pier, in water generally less than 10 feet deep,
using an impact hammer. The timing of this work depends on operational
schedules at the berths. The sister piles may be installed either
before or after the bulkheads are constructed.
Description of Marine Mammals in the Area of the Specified Activity
Five marine mammal species, including one cetacean and four
pinnipeds, may inhabit or transit the waters near the Shipyard in the
lower Piscataqua River during the specified activity. These include the
harbor porpoise (Phocoena phocoena), Gray seal (Halichoerus grypus),
harbor seal (Phoca vitulina), hooded seal (Crystphora cristata), and
harp seal (Pagophilus groenlandicus). None of the marine mammals that
may be found in the Piscataqua River are listed under the Endangered
Species Act (ESA). Table 2 lists the marine mammal species that could
occur in the vicinity of the Shipyard and their estimated densities
within the Project area. As there are not specific density data for any
of the species in the Piscataqua River, density data from the nearshore
zone outside the mouth the Piscataqua River in the Atlantic Ocean have
been used instead. Therefore, it can be assumed that the density
estimates presented here for each species are conservative and much
higher than densities that would typically be expected in an estuarine
environment such as the lower Piscataqua River in the vicinity of the
Shipyard.
Table 2--Marine Mammal Species Potentially Present in the Piscataqua River in the Vicinity of the Shipyard
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Approximate density in the vicinity of the
Relative Season(s) of project area (individuals per km\2\) \3\
Species Stock(s) abundance \1\ occurrence in occurrence -----------------------------------------------
Piscataqua River Winter Spring Summer Fall
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Harbor Porpoise, Phocoena 79,883 (CV = 0.32)............ Occasional use.... Spring to Fall 1.2122 1.1705 0.7903 0.9125
phocoena, Gulf of Maine/Bay of (April to
Fundy stock. December). \4\
Gray Seal, Halichoerus grypus, 331,000 \2\................... Common............ Year-round........ 0.2202 0.2202 0.2202 0.2202
Western North Atlantic stock.
Harbor Seal, Phoca vitulina, 75,834 (CV = 0.15)............ Common............ Year-round........ 0.1998 0.1998 0.1998 0.1998
Western North Atlantic stock.
Hooded Seal, Crystphora 592,100 \2\................... Rare.............. Winter to Spring N/A N/A N/A N/A
cristata, Western North (January-May).
Atlantic stock.
Harp Seal, Pagophilus 7,100,000..................... Rare.............. Winter to Spring 0.0125 0.0125 0.0125 0.0125
groenlandicus, Western North (January-May).
Atlantic stock.
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Source: Waring et al., 2015, except where noted.
Notes:
\1\ No population estimate is available for the U.S. western North Atlantic stock; therefore, the best population estimates are those for the Canadian
populations as reported in Waring et al., 2015.
\2\ Source: Waring et al., 2007. The population estimate for the Western North Atlantic hooded seal population was not updated in Waring et al., 2015.
\3\ Density data are taken from the Navy Marine Species Density Database (Crain 2015; Krause 2015). It should be noted that these data overestimate the
potential species density in the Piscataqua River. The Navy Marine Species Density Database data presented in the table are based on a relative
environmental suitability study and represent data with low confidence. These data are generally used for broad-scale offshore activities; however,
due to a lack of any other data within the general Project area, these data are presented as the best available data for the Piscataqua River.
\4\ Densities shown for seasons when each species would not be likely to occur in the river.
Key: CV = coefficient of variation. km\2\ = square kilometer.
We have reviewed the Navy's detailed species descriptions,
including life history information, for accuracy and completeness and
refer the reader to Section 3 of the Navy's Application instead of
reprinting the information here. Please also refer to NMFS' Web site
(www.nmfs.noaa.gov/pr/species/mammals) for generalized species
accounts.
Harbor Porpoise
Harbor porpoises are found commonly in coastal and offshore waters
of both the Atlantic and Pacific Oceans. In the western North Atlantic,
the species is found in both U.S. and Canadian waters. More
specifically, the species can be found between West Greenland and Cape
Hatteras, North Carolina (NOAA Fisheries Service
[[Page 52618]]
2014a). Based on genetic analysis, it is assumed that harbor porpoises
in the U.S. and Canadian waters are divided into four populations, as
follows: (1) Gulf of St. Lawrence; (2) Newfoundland; (3) Greenland; and
(4) Gulf of Maine/Bay of Fundy. For management purposes in U.S. waters,
harbor porpoises have been divided into 10 stocks along both the East
and West Coasts. Of those 10 stocks, only one, the Gulf of Maine/Bay of
Fundy stock, is found along the U.S. East Coast, and thus only
individuals from this stock could be found in the Project area. The
species is primarily found over the Continental Shelf in waters less
than approximately 500 feet deep (Waring et al., 2014). In general, the
species is commonly found in bays, estuaries, and harbors (NOAA
Fisheries Service 2014a).
Line-transect surveys have been conducted in the Gulf of Maine
between 1991 and 2011. Based on the 2011 aerial surveys, the best
abundance estimate for the Gulf of Maine/Bay of Fundy stock of harbor
porpoise is 79,883 animals (CV = 0.32). The aerial surveys included
central Virginia to the lower Bay of Fundy. The minimum population
estimate is 61,415 animals (Waring et al., 2014). Because no trend
analysis has been conducted for this stock, no population trend is
available. A Bayesian population model was used to determine the
currently accepted population growth rate. Fertility data and age-at-
death data from stranded animals and animals taken in gillnets were
used for the model (Waring et al., 2014). It was then determined that
the potential natural growth rate for the Gulf of Maine/Bay of Fundy
stock of harbor porpoises was 0.046 (Waring et al., 2014). The harbor
porpoise is likely the most abundant cetacean within the Piscataqua
River (Smith n.d.)
Gray Seal
Gray seals, which are members of the ``true seal'' family
(Phocidae), are a coastal species that generally remains within the
Continental Shelf region. Gray seals can be found on both sides of the
North Atlantic. Within this area, the species is split into three
primary populations: (1) Eastern Canada, (2) northwestern Europe, and
(3) the Baltic Sea (Katona et al., 1993). Gray seals within U.S. waters
are considered the western North Atlantic stock and are expected to be
part of the eastern Canadian population (Waring et al., 2014). In U.S.
waters, year-round breeding of approximately 400 animals has been
documented on areas of outer Cape Cod and Mukeget Island in
Massachusetts. In general, this species can be found year-round in the
coastal waters of the Gulf of Maine (Waring et al., 2014).
There are currently no population estimates for the western North
Atlantic gray seal stock (Waring et al., 2014). However, estimates are
available for portions of the total population for certain time periods
(Waring et al., 2014). For example, between 1993 and 2004, the Gray
seal population in Canada was estimated at between 144,000 and 223,220
individuals. This estimate was based on three separate surveys and also
depended on the population-estimation model that was used (Mohn and
Bowen 1996; Department of Fisheries and Oceans 2003; Trzcinski et al.,
2005). The most recent Canadian gray seal population estimate is
331,000. This estimate is based on surveys conducted during 2012 in the
Gulf of St. Lawrence, Nova Scotia Eastern Shore, and Sable Island
(Waring et al., 2014). In U.S. waters, gray seals are known to pup at
three separate locations: (1) Muskeget Island, Massachusetts; (2) Green
Island, Maine; and (3) Seal Island, Maine. Surveys of these areas
indicate that in these colonies pup production is increasing, as are
the colony populations. General population increases in U.S. waters are
likely a result of this natural increase and immigration of individuals
from Canadian populations (Waring et al., 2014).
Harbor Seal
Harbor seals are also members of the true seal family (Phocidae)
and can be found in nearshore waters along both the North Atlantic and
North Pacific coasts, generally at latitudes above 30[deg] N. (Burns
2009). In the western Atlantic Ocean, the harbor seal's range extends
from the eastern Canadian Arctic to New York; however, they can be
found as far south as the Carolinas (Waring et al., 2014). In New
England, the species can be found in coastal waters year-round (Waring
et al., 2014). Overall, there are five recognized subspecies of harbor
seal, two of which occur in the Atlantic Ocean. The western Atlantic
harbor seal (Phoca vitulina concolor) is the subspecies likely to occur
in the project area. There is some uncertainly about the overall
population stock structure of harbor seals in the western North
Atlantic Ocean. However, it is theorized that harbor seals along the
eastern U.S. and Canada are all from a single population (Temte et al.,
1991).
An aerial abundance survey was conducted in 2012 during the pupping
season along the entire Maine coast. As a result of this survey, the
best estimate of abundance for the western North Atlantic stock of
harbor seal was 70,142 animals. The minimum population was estimated as
55,409 animals (also based on the 2012 aerial abundance survey). No
trend analysis has been conducted for this species, likely because of
the long interval between the 2012 survey and the previous 2001 survey
and the somewhat imprecise abundance estimates that were generated from
them. In the Piscataqua River, harbor seals are the most abundant
pinniped species (Smith n.d.).
Hooded Seal
Hooded seals are also members of the true seal family (Phocidae)
and are generally found in deeper waters or on drifting pack ice. The
world population of hooded seals has been divided into three stocks,
which coincide with specific breeding areas, as follows: (1) Northwest
Atlantic, (2) Greenland Sea, and (3) White Sea (Waring et al., 2007).
The hooded seal is a highly migratory species, and its range can extend
from the Canadian arctic to Puerto Rico. In the U.S. waters, the
species has an increasing presence in the coastal waters between Maine
and Florida (Waring et al., 2007). In the United States, they are
considered members of the western North Atlantic stock and generally
occur in New England waters from January through May and further south
in the summer and fall seasons (Waring et al., 2007).
Population abundance of hooded seals in the western North Atlantic
is derived from pup production estimates. These estimates are developed
from whelping pack surveys. The most recent population estimate in the
western North Atlantic was derived in 2005. There have been no recent
surveys conducted or population estimates developed for this species.
The 2005 best population estimate for hooded seals is 592,100
individuals, with a minimum population estimate of 512,000 individuals
(Waring et al., 2007). Currently, not enough data are available to
determine what percentage of this estimate may represent the population
within U.S. waters. A population trend also cannot be developed for
this species due to a lack of sufficient data. Hooded seals are known
to occur in the Piscataqua River; however, they are not as abundant as
the more commonly observed harbor seal. Anecdotal sighting information
indicates that two hooded seals were observed from the Shipyard in
August 2009, but no other observations have been recorded (Trefry
November 20, 2015).
[[Page 52619]]
Harp Seal
Harp seals are also members of the true seal family and classified
into three stocks, which coincide with specific pupping sites on pack
ice, as follows: (1) Eastern Canada, including the areas off the coast
of Newfoundland and Labrador and the area near the Magdalen Islands in
the Gulf of St. Lawrence; (2) the West Ice off eastern Greenland, and
(3) the ice in the White Sea off the coast of Russia (Waring et al.,
2014). The harp seal is a highly migratory species, and its range can
extend from the Canadian arctic to New Jersey. In U.S. waters, the
species has an increasing presence in the coastal waters between Maine
and New Jersey (Waring et al., 2014). In the United States, they are
considered members of the western North Atlantic stock and generally
occur in New England waters from January through May in the winter and
spring (Waring et al., 2014). The observed influx of harp seals and
geographic distribution in New England to mid-Atlantic waters is based
primarily on strandings and secondarily on fishery bycatch.
Population abundance of harp seals in the western North Atlantic is
derived from aerial surveys and mark-recapture (Waring et al., 2014).
The most recent population estimate in the western North Atlantic was
derived in 2012 from an aerial harp seal survey. The 2012 best
population estimate for hooded seals is 7.1 million individuals (Waring
et al., 2014). Currently, not enough data are available to determine
what percentage of this estimate may represent the population within
U.S. waters. A population trend also cannot be developed for this
species due to a lack of sufficient data, as recent increases in
strandings may not be indicative of population size. Harp seals are
known to occur in the Piscataqua River; however, they are not as
abundant as the more commonly observed harbor seal (Crain 2015).
Potential Effects of the Specified Activity on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
stressors, (e.g., pile driving,) and potential mitigation activities,
associated with the proposed waterfront improvement project may impact
marine mammals and their habitat. The ``Estimated Take by Incidental
Harassment'' section later in this document will include a quantitative
analysis of the number of individuals that are expected to be taken by
this activity. The ``Negligible Impact Analysis'' section will include
the analysis of how this specific activity will impact marine mammals
and will consider the content of this section, the ``Estimated Take by
Incidental Harassment'' section, and the ``Proposed Mitigation''
section to draw conclusions regarding the likely impacts of this
activity on the reproductive success or survivorship of individuals and
from that on the affected marine mammal populations or stocks. In the
following discussion, we provide general background information on
sound and marine mammal hearing before considering potential effects to
marine mammals from sound produced by pile driving.
Description of Sound Sources
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in hertz (Hz) or cycles per second. Wavelength is the
distance between two peaks of a sound wave; lower frequency sounds have
longer wavelengths than higher frequency sounds and attenuate
(decrease) more rapidly in shallower water. Amplitude is the height of
the sound pressure wave or the `loudness' of a sound and is typically
measured using the decibel (dB) scale. A dB is the ratio between a
measured pressure (with sound) and a reference pressure (sound at a
constant pressure, established by scientific standards). It is a
logarithmic unit that accounts for large variations in amplitude;
therefore, relatively small changes in dB ratings correspond to large
changes in sound pressure. When referring to sound pressure levels
(SPLs; the sound force per unit area), sound is referenced in the
context of underwater sound pressure to 1 microPascal ([mu]Pa). One
pascal is the pressure resulting from a force of one newton exerted
over an area of one square meter. The source level (SL) represents the
sound level at a distance of 1 m from the source (referenced to 1
[mu]Pa). The received level is the sound level at the listener's
position. Note that all underwater sound levels in this document are
referenced to a pressure of 1 [mu]Pa and all airborne sound levels in
this document are referenced to a pressure of 20 [mu]Pa.
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Rms is calculated by squaring all of the
sound amplitudes, averaging the squares, and then taking the square
root of the average (Urick, 1983). Rms accounts for both positive and
negative values; squaring the pressures makes all values positive so
that they may be accounted for in the summation of pressure levels
(Hastings and Popper, 2005). This measurement is often used in the
context of discussing behavioral effects, in part because behavioral
effects, which often result from auditory cues, may be better expressed
through averaged units than by peak pressures.
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in all
directions away from the source (similar to ripples on the surface of a
pond), except in cases where the source is directional. The
compressions and decompressions associated with sound waves are
detected as changes in pressure by aquatic life and man-made sound
receptors such as hydrophones.
Even in the absence of sound from the specified activity, the
underwater environment is typically loud due to ambient sound. Ambient
sound is defined as environmental background sound levels lacking a
single source or point (Richardson et al., 1995), and the sound level
of a region is defined by the total acoustical energy being generated
by known and unknown sources. These sources may include physical (e.g.,
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds
produced by marine mammals, fish, and invertebrates), and anthropogenic
sound (e.g., vessels, dredging, aircraft, construction). A number of
sources contribute to ambient sound, including the following
(Richardson et al., 1995):
Wind and waves: The complex interactions between wind and
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of
naturally occurring ambient noise for frequencies between 200 Hz and 50
kHz (Mitson, 1995). In general, ambient sound levels tend to increase
with increasing wind speed and wave height. Surf noise becomes
important near shore, with measurements collected at a distance of 8.5
km from shore showing an increase of 10 dB in the 100 to 700 Hz band
during heavy surf conditions.
Precipitation: Sound from rain and hail impacting the
water surface can become an important component of total noise at
frequencies above 500 Hz, and possibly down to 100 Hz during quiet
times.
Biological: Marine mammals can contribute significantly to
ambient noise levels, as can some fish and shrimp. The frequency band
for biological contributions is from approximately 12 Hz to over 100
kHz.
[[Page 52620]]
Anthropogenic: Sources of ambient noise related to human
activity include transportation (surface vessels and aircraft),
dredging and construction, oil and gas drilling and production, seismic
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise
typically dominates the total ambient noise for frequencies between 20
and 300 Hz. In general, the frequencies of anthropogenic sounds are
below 1 kHz and, if higher frequency sound levels are created, they
attenuate rapidly (Richardson et al., 1995). Sound from identifiable
anthropogenic sources other than the activity of interest (e.g., a
passing vessel) is sometimes termed background sound, as opposed to
ambient sound.
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In the vicinity of the Project area, the average broadband ambient
underwater noise levels are commonly 52.8 to 80.5 dB SEL re 1[mu]Pa
with substantially higher maximum peak readings (79.9 to 103.9
Lpeak dB re 1[mu]Pa) due to passing boats and industrial
noise (ESS Group, Inc. 2015). However, boat traffic was limited the day
of the study; three boats passed at a distance greater than 66 yards
from site. Therefore, given the short duration of the measurements, it
would be difficult to determine whether vessel noise associated with
the Proposed Action would add greatly to the existing background vessel
noise in the lower Piscataqua River. However, based on these
measurements, it cannot be assumed that the sound produced by vibratory
pile driving would be completely masked by background vessel noise,
especially in areas close to the vibratory hammer.
There are two general categories of sound types: Impulse and non-
pulse. Vibratory pile driving is considered to be continuous or non-
pulsed while impact pile driving is considered to be an impulse or
pulsed sound type. The distinction between these two sound types is
important because they have differing potential to cause physical
effects, particularly with regard to hearing (e.g., Ward, 1997 in
Southall et al., 2007). Please see Southall et al., (2007) for an in-
depth discussion of these concepts.
Pulsed sound sources (e.g., explosions, gunshots, sonic booms,
impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) and
occur either as isolated events or repeated in some succession. Pulsed
sounds are all characterized by a relatively rapid rise from ambient
pressure to a maximal pressure value followed by a rapid decay period
that may include a period of diminishing, oscillating maximal and
minimal pressures, and generally have an increased capacity to induce
physical injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband, or broadband, brief or
prolonged, and may be either continuous or non-continuous (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems (such as
those used by the U.S. Navy). The duration of such sounds, as received
at a distance, can be greatly extended in a highly reverberant
environment.
Impact hammers operate by repeatedly dropping a heavy piston onto a
pile to drive the pile into the substrate. Sound generated by impact
hammers is characterized by rapid rise times and high peak levels, a
potentially injurious combination (Hastings and Popper, 2005).
Vibratory hammers install piles by vibrating them and allowing the
weight of the hammer to push them into the sediment. Vibratory hammers
produce significantly less sound than impact hammers. Peak SPLs may be
180 dB or greater, but are generally 10 to 20 dB lower than SPLs
generated during impact pile driving of the same-sized pile (Oestman et
al., 2009). Rise time is slower, reducing the probability and severity
of injury, and sound energy is distributed over a greater amount of
time (Nedwell and Edwards, 2002; Carlson et al., 2005).
Table 3--Representative Sound Levels of Anthropogenic Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Frequency
Sound source range (Hz) Underwater sound level Reference
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small vessels............................ 250-1,000 151 dB rms at 1 m........... Richardson et al., 1995.
Tug docking gravel barge................. 200-1,000 149 dB rms at 100 m......... Blackwell and Greene, 2002.
Vibratory driving of 72-in steel pipe 10-1,500 180 dB rms at 10 m.......... Reyff, 2007.
pile.
Impact driving of 36-in steel pipe pile.. 10-1,500 195 dB rms at 10 m.......... Laughlin, 2005.
Impact driving of 66-in cast-in-steel- 10-1,500 195 dB rms at 10 m.......... Reviewed in Hastings and Popper, 2005.
shell (CISS) pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------
The likely or possible impacts of the proposed project on marine
mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors could result from the physical
presence of the equipment and personnel. Any impacts to marine mammals,
however, are expected to primarily be acoustic in nature.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals,
and exposure to sound can have deleterious effects. To appropriately
assess these potential effects, it is necessary to understand the
frequency ranges marine mammals are able to hear. Current data indicate
that not all marine mammal species have equal hearing capabilities
(e.g., Richardson et al., 1995; Wartzok
[[Page 52621]]
and Ketten, 1999). To reflect this, Southall et al., (2007) recommended
that marine mammals be divided into functional hearing groups based on
measured or estimated hearing ranges on the basis of available
behavioral data, audiograms derived using auditory evoked potential
techniques, anatomical modeling, and other data. The lower and/or upper
frequencies for some of these functional hearing groups have been
modified from those designated by Southall et al., (2007). The
functional groups and the associated frequencies are indicated below
(note that these frequency ranges do not necessarily correspond to the
range of best hearing, which varies by species):
Low-frequency cetaceans (mysticetes): Functional hearing
is estimated to occur between approximately 7 Hz and 25 kHz (extended
from 22 kHz; Watkins, 1986; Lucifredi and Stein, 2007; Ketten and
Mountain, 2009; Tubelli et al., 2012);
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Functional hearing is estimated to occur
between approximately 150 Hz and 160 kHz;
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; now considered to
include two members of the genus Lagenorhynchus on the basis of recent
echolocation data and genetic data [May-Collado and Agnarsson, 2006;
Kyhn et al., 2009, 2010; Tougaard et al., 2010]): Functional hearing is
estimated to occur between approximately 200 Hz and 180 kHz; and
Pinnipeds in water: Functional hearing is estimated to
occur between approximately 75 Hz to 100 kHz for Phocidae (true seals)
and between 100 Hz and 48 kHz for Otariidae (eared seals), with the
greatest sensitivity between approximately 700 Hz and 20 kHz. The
pinniped functional hearing group was modified from Southall et al.,
(2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Kastelein et al., 2009; Reichmuth et al., 2013).
The single cetacean species likely to occur in the proposed project
area and for which take is requested, is classified as a high-frequency
cetacean (i.e., harbor porpoise) (Southall et al., 2007). Additionally,
gray seals, harbor seals, hooded seals, and harp seals are classified
as members of the phocid pinnipeds in-water functional hearing group.
Acoustic Effects, Underwater
Potential Effects of Pile Driving Sound--The effects of sounds from
pile driving might result in one or more of the following: Temporary or
permanent hearing impairment, non-auditory physical or physiological
effects, behavioral disturbance, and masking (Richardson et al., 1995;
Gordon et al., 2004; Nowacek et al., 2007; Southall et al., 2007). The
effects of pile driving on marine mammals are dependent on several
factors, including the size, type, and depth of the animal; the depth,
intensity, and duration of the pile driving sound; the depth of the
water column; the substrate of the habitat; the standoff distance
between the pile and the animal; and the sound propagation properties
of the environment. Impacts to marine mammals from pile driving
activities are expected to result primarily from acoustic pathways. As
such, the degree of effect is intrinsically related to the received
level and duration of the sound exposure, which are in turn influenced
by the distance between the animal and the source. The further away
from the source, the less intense the exposure should be.
The substrate and depth of the habitat affect the sound propagation
properties of the environment. Shallow environments are typically more
structurally complex, which leads to rapid sound attenuation. In
addition, substrates that are soft (e.g., sand) would absorb or
attenuate the sound more readily than hard substrates (e.g., rock)
which may reflect the acoustic wave. Soft porous substrates would also
likely require less time to drive the pile, and possibly less forceful
equipment, which would ultimately decrease the intensity of the
acoustic source. Much of the shoreline in the project area has been
characterized as hard shores (rocky intertidal). In general, rocky
intertidal areas consist of bedrock that alternates between marine and
terrestrial habitats, depending on the tide. Rocky intertidal areas are
characterized by bedrock, stones, or boulders that singly or in
combination cover 75 percent or more of an area that is covered less
than 30 percent by vegetation.
In the absence of mitigation, impacts to marine species would be
expected to result from physiological and behavioral responses to both
the type and strength of the acoustic signature (Viada et al., 2008).
The type and severity of behavioral impacts are more difficult to
document due to limited studies addressing the behavioral effects of
impulse sounds on marine mammals. Potential effects from impulsive
sound sources can range in severity from effects such as behavioral
disturbance or tactile perception to physical discomfort, slight injury
of the internal organs and the auditory system, or mortality (Yelverton
et al., 1973).
Hearing Impairment and Other Physical Effects--Marine mammals
exposed to high intensity sound repeatedly or for prolonged periods can
experience hearing threshold shift (TS), which is the loss of hearing
sensitivity at certain frequency ranges (Kastak et al., 1999; Schlundt
et al., 2000; Finneran et al., 2003, 2005). TS can be permanent (PTS),
in which case the loss of hearing sensitivity is not recoverable, or
temporary (TTS), in which case the animal's hearing threshold would
recover over time (Southall et al., 2007). Marine mammals depend on
acoustic cues for vital biological functions, (e.g., orientation,
communication, finding prey, avoiding predators); thus, TTS may result
in reduced fitness in survival and reproduction. However, this depends
on the frequency and duration of TTS, as well as the biological context
in which it occurs. TTS of limited duration, occurring in a frequency
range that does not coincide with that used for recognition of
important acoustic cues, would have little to no effect on an animal's
fitness. Repeated sound exposure that leads to TTS could cause PTS. PTS
constitutes injury, but TTS does not (Southall et al., 2007). The
following subsections discuss in somewhat more detail the possibilities
of TTS, PTS, and non-auditory physical effects.
Temporary Threshold Shift--TTS is the mildest form of hearing
impairment that can occur during exposure to a strong sound (Kryter,
1985). While experiencing TTS, the hearing threshold rises, and a sound
must be stronger in order to be heard. In terrestrial mammals, TTS can
last from minutes or hours to days (in cases of strong TTS). For sound
exposures at or somewhat above the TTS threshold, hearing sensitivity
in both terrestrial and marine mammals recovers rapidly after exposure
to the sound ends. Few data on sound levels and durations necessary to
elicit mild TTS have been obtained for marine mammals, and none of the
published data concern TTS elicited by exposure to multiple pulses of
sound. Available data on TTS in marine mammals are summarized in
Southall et al., (2007).
Given the available data, the received level of a single pulse
(with no frequency weighting) might need to be approximately 186 dB re
1 [mu]Pa\2\-s (i.e., 186 dB sound exposure level [SEL] or approximately
221-226 dB p-p [peak]) in order to produce brief, mild TTS.
[[Page 52622]]
Exposure to several strong pulses that each have received levels near
190 dB rms (175-180 dB SEL) might result in cumulative exposure of
approximately 186 dB SEL and thus slight TTS in a small odontocete,
assuming the TTS threshold is (to a first approximation) a function of
the total received pulse energy (Southall et al. 2007).
The above TTS information for odontocetes is derived from studies
on the bottlenose dolphin (Tursiops truncatus) and beluga whale. There
is no published TTS information for other species of cetaceans.
However, preliminary evidence from a harbor porpoise exposed to pulsed
sound suggests that its TTS threshold may have been lower (Lucke et
al., 2009). Furthermore, harbor porpoise are high frequency hearing
specialists so they are not as sensitive to lower frequency sounds
produced by pile driving as much as belugas and bottlenose dolphins
are. As summarized above, data that are now available imply that TTS is
unlikely to occur unless odontocetes are exposed to pile driving pulses
stronger than 180 dB re 1 [mu]Pa rms.
Permanent Threshold Shift--When PTS occurs, there is physical
damage to the sound receptors in the ear. In severe cases, there can be
total or partial deafness, while in other cases the animal has an
impaired ability to hear sounds in specific frequency ranges (Kryter,
1985). There is no specific evidence that exposure to pulses of sound
can cause PTS in any marine mammal. However, given the possibility that
mammals close to a sound source can incur TTS, it is possible that some
individuals might incur PTS. Single or occasional occurrences of mild
TTS are not indicative of permanent auditory damage, but repeated or
(in some cases) single exposures to a level well above that causing TTS
onset might elicit PTS.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals but are assumed to be similar to those in humans and
other terrestrial mammals, based on anatomical similarities. PTS might
occur at a received sound level at least several decibels above that
inducing mild TTS if the animal were exposed to strong sound pulses
with rapid rise time. Based on data from terrestrial mammals, a
precautionary assumption is that the PTS threshold for impulse sounds
(such as pile driving pulses as received close to the source) is at
least 6 dB higher than the TTS threshold on a peak-pressure basis and
probably greater than 6 dB (Southall et al., 2007). On an SEL basis,
Southall et al., (2007) estimated that received levels would need to
exceed the TTS threshold by at least 15 dB for there to be risk of PTS.
Thus, for cetaceans, Southall et al., (2007) estimate that the PTS
threshold might be an M-weighted SEL (for the sequence of received
pulses) of approximately 198 dB re 1 [mu]Pa\2\-s (15 dB higher than the
TTS threshold for an impulse). Given the higher level of sound
necessary to cause PTS as compared with TTS, it is considerably less
likely that PTS could occur.
Although no marine mammals have been shown to experience TTS or PTS
as a result of being exposed to pile driving activities, captive
bottlenose dolphins and beluga whales exhibited changes in behavior
when exposed to strong pulsed sounds (Finneran et al., 2000, 2003,
2005). The animals tolerated high received levels of sound before
exhibiting aversive behaviors. Experiments on a beluga whale showed
that exposure to a single watergun impulse at a received level of 207
kPa (30 psi) p-p, which is equivalent to 228 dB p-p, resulted in a 7
and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, respectively.
Thresholds returned to within 2 dB of the pre-exposure level within
four minutes of the exposure (Finneran et al., 2003). Although the
source level of pile driving from one hammer strike is expected to be
much lower than the single watergun impulse cited here, animals being
exposed for a prolonged period to repeated hammer strikes could receive
more sound exposure in terms of SEL than from the single watergun
impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the aforementioned
experiment (Finneran et al., 2003). However, in order for marine
mammals to experience TTS or PTS, the animals have to be close enough
to be exposed to high intensity sound levels for a prolonged period of
time. Based on the best scientific information available, these SPLs
are far below the thresholds that could cause TTS or the onset of PTS.
Non-auditory Physiological Effects--Non-auditory physiological
effects or injuries that theoretically might occur in marine mammals
exposed to strong underwater sound include stress, neurological
effects, bubble formation, resonance effects, and other types of organ
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies
examining such effects are limited. In general, little is known about
the potential for pile driving to cause auditory impairment or other
physical effects in marine mammals. Available data suggest that such
effects, if they occur at all, would presumably be limited to short
distances from the sound source and to activities that extend over a
prolonged period. The available data do not allow identification of a
specific exposure level above which non-auditory effects can be
expected (Southall et al., 2007) or any meaningful quantitative
predictions of the numbers (if any) of marine mammals that might be
affected in those ways. Marine mammals that show behavioral avoidance
of pile driving, including some odontocetes and some pinnipeds, are
especially unlikely to incur auditory impairment or non-auditory
physical effects.
Disturbance Reactions
Disturbance includes a variety of effects, including subtle changes
in behavior, more conspicuous changes in activities, and displacement.
Behavioral responses to sound are highly variable and context-specific
and reactions, if any, depend on species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
time of day, and many other factors (Richardson et al., 1995; Wartzok
et al., 2003; Southall et al., 2007).
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure. Behavioral state may affect the type of response as well. For
example, animals that are resting may show greater behavioral change in
response to disturbing sound levels than animals that are highly
motivated to remain in an area for feeding (Richardson et al., 1995;
NRC, 2003; Wartzok et al., 2003).
Controlled experiments with captive marine mammals showed
pronounced behavioral reactions, including avoidance of loud sound
sources (Ridgway et al., 1997; Finneran et al., 2003). Observed
responses of wild marine mammals to loud pulsed sound sources
(typically seismic guns or acoustic harassment devices, but also
including pile driving) have been varied but often consist of avoidance
behavior or other behavioral changes suggesting discomfort (Morton and
Symonds, 2002; Thorson and Reyff, 2006; see also Gordon et al., 2004;
Wartzok et al., 2003; Nowacek et al., 2007). Responses to continuous
sound, such as vibratory pile installation, have not been documented as
well as responses to pulsed sounds.
With both types of pile driving, it is likely that the onset of
pile driving
[[Page 52623]]
could result in temporary, short term changes in an animal's typical
behavior and/or avoidance of the affected area. These behavioral
changes may include (Richardson et al., 1995): Changing durations of
surfacing and dives, number of blows per surfacing, or moving direction
and/or speed; reduced/increased vocal activities; changing/cessation of
certain behavioral activities (such as socializing or feeding); visible
startle response or aggressive behavior (such as tail/fluke slapping or
jaw clapping); avoidance of areas where sound sources are located; and/
or flight responses (e.g., pinnipeds flushing into water from haul-outs
or rookeries). Pinnipeds may increase their haul-out time, possibly to
avoid in-water disturbance (Thorson and Reyff, 2006).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be expected to be biologically significant if the
change affects growth, survival, or reproduction. Significant
behavioral modifications that could potentially lead to effects on
growth, survival, or reproduction include:
Drastic changes in diving/surfacing patterns (such as
those thought to cause beaked whale stranding due to exposure to
military mid-frequency tactical sonar);
Habitat abandonment due to loss of desirable acoustic
environment; and
Cessation of feeding or social interaction.
The onset of behavioral disturbance from anthropogenic sound
depends on both external factors (characteristics of sound sources and
their paths) and the specific characteristics of the receiving animals
(hearing, motivation, experience, demography) and is difficult to
predict (Southall et al., 2007).
Auditory Masking
Natural and artificial sounds can disrupt behavior by masking, or
interfering with, a marine mammal's ability to hear other sounds.
Masking occurs when the receipt of a sound is interfered with by
another coincident sound at similar frequencies and at similar or
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular frequencies for
marine mammals that utilize sound for vital biological functions.
Masking can interfere with detection of acoustic signals such as
communication calls, echolocation sounds, and environmental sounds
important to marine mammals. Therefore, under certain circumstances,
marine mammals whose acoustical sensors or environment are being
severely masked could also be impaired from maximizing their
performance fitness in survival and reproduction. If the coincident
(masking) sound were anthropogenic, it could be potentially harassing
if it disrupted hearing-related behavior. It is important to
distinguish TTS and PTS, which persist after the sound exposure, from
masking, which occurs only during the sound exposure. Because masking
(without resulting in TS) is not associated with abnormal physiological
function, it is not considered a physiological effect, but rather a
potential behavioral effect.
Masking occurs at the frequency band which the animals utilize so
the frequency range of the potentially masking sound is important in
determining any potential behavioral impacts. Because sound generated
from in-water vibratory pile driving is mostly concentrated at low
frequency ranges, it may have less effect on high frequency
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls
and other potentially important natural sounds such as surf and prey
sound. It may also affect communication signals when they occur near
the sound band and thus reduce the communication space of animals
(e.g., Clark et al., 2009) and cause increased stress levels (e.g.,
Foote et al., 2004; Holt et al., 2009).
Masking affects both senders and receivers of the signals and can
potentially have long-term chronic effects on marine mammal species and
populations. Recent research suggests that low frequency ambient sound
levels have increased by as much as 20 dB (more than three times in
terms of SPL) in the world's ocean from pre-industrial periods, and
that most of these increases are from distant shipping (Hildebrand,
2009). All anthropogenic sound sources, such as those from vessel
traffic, pile driving, and dredging activities, contribute to the
elevated ambient sound levels, thus intensifying masking.
The most intense underwater sounds in the proposed action are those
produced by impact pile driving. Given that the energy distribution of
pile driving covers a broad frequency spectrum, sound from these
sources would likely be within the audible range of marine mammals
present in the project area. Impact pile driving activity is relatively
short-term, with rapid pulses occurring for approximately fifteen
minutes per pile. The probability for impact pile driving resulting
from this proposed action masking acoustic signals important to the
behavior and survival of marine mammal species is likely to be
negligible. Vibratory pile driving is also relatively short-term, with
rapid oscillations occurring for approximately one and a half hours per
pile. It is possible that vibratory pile driving resulting from this
proposed action may mask acoustic signals important to the behavior and
survival of marine mammal species, but the short-term duration and
limited affected area would result in insignificant impacts from
masking. Any masking event that could possibly rise to Level B
harassment under the MMPA would occur concurrently within the zones of
behavioral harassment already estimated for vibratory and impact pile
driving, and which have already been taken into account in the exposure
analysis.
Acoustic Effects, Airborne
Marine mammals that occur in the project area could be exposed to
airborne sounds associated with pile driving that have the potential to
cause harassment, depending on their distance from pile driving
activities. Airborne pile driving sound would not impact cetaceans
because sound from atmospheric sources does not transmit well
underwater (Richardson et al., 1995); thus, airborne sound may only be
an issue for pinnipeds either hauled-out or looking with heads above
water in the project area. Most likely, airborne sound would cause
behavioral responses similar to those discussed above in relation to
underwater sound. For instance, anthropogenic sound could cause hauled-
out pinnipeds to exhibit changes in their normal behavior, such as
reduction in vocalizations, or cause them to temporarily abandon their
habitat and move further from the source. Studies by Blackwell et al.,
(2004) and Moulton et al., (2005) indicate a tolerance or lack of
response to unweighted airborne sounds as high as 112 dB peak and 96 dB
rms. However, since there are no regular haul-outs in the vicinity of
the site of the proposed project area, we believe that incidents of
incidental take resulting from airborne sound or visual disturbance are
unlikely.
Vessel Interaction
Besides being susceptible to vessel strikes, cetacean and pinniped
responses to vessels may result in behavioral changes, including
greater variability in the dive, surfacing, and respiration patterns;
changes in vocalizations; and changes in swimming speed or direction
(NRC 2003). There
[[Page 52624]]
will be a temporary and localized increase in vessel traffic during
construction.
Potential Effects on Marine Mammal Habitat
The proposed activities at Portsmouth Naval Shipyard would not
result in permanent impacts to habitats used directly by marine
mammals, but may have potential short-term impacts to food sources such
as forage fish and may affect acoustic habitat (see masking discussion
above). There are no known foraging hotspots or other ocean bottom
structure of significant biological importance to marine mammals
present in the marine waters of the project area. Therefore, the main
impact issue associated with the proposed activity would be temporarily
elevated sound levels and the associated direct effects on marine
mammals, as discussed previously in this document. The most likely
impact to marine mammal habitat would be the effect of pile driving on
likely marine mammal prey (i.e., fish) and minor impacts to the
immediate substrate during installation and removal of piles.
Potential Pile Driving Effects on Prey
Construction activities may produce both pulsed (i.e., impact pile
driving) and continuous (i.e., vibratory pile driving) sounds. Fish
react to sounds which are especially strong and/or intermittent low-
frequency sounds. Short duration, sharp sounds can cause overt or
subtle changes in fish behavior and local distribution. Hastings and
Popper (2005) identified several studies that suggest fish may relocate
to avoid certain areas of sound energy. Additional studies have
documented effects of pile driving (or other types of sounds) on fish,
although several are based on studies in support of large, multiyear
bridge construction projects (e.g., Scholik and Yan, 2001, 2002; Popper
and Hastings, 2009). Sound pulses at received levels of 160 dB re 1
[mu]Pa may cause subtle changes in fish behavior. SPLs of 180 dB may
cause noticeable changes in behavior (Pearson et al., 1992; Skalski et
al., 1992). SPLs of sufficient strength have been known to cause injury
to fish and fish mortality. The most likely impact to fish from pile
driving activities at the project area would be temporary behavioral
avoidance of the area. The duration of fish avoidance of this area
after pile driving stops is unknown, but a rapid return to normal
recruitment, distribution and behavior is anticipated. In general,
impacts to marine mammal prey species are expected to be minor and
temporary due to the short timeframe for the project.
Effects to Foraging Habitat
During the course of the proposed project, various activities are
expected to disturb the sediment. These activities include pile
driving, dredging, and filling. In order to minimize the amount of
debris, sediment, and silt escaping when backfilling the Berth 11
bulkhead, the Navy will install geotextile fabric against the interior
of the bulkhead to catch debris, sediment, and silt forced through
seams in the bulkhead when the backfill is compacted. In addition, a
temporary silt curtain and boom would be installed outside of Berth 11,
approximately 18 feet off the berth, during backfilling to catch
additional debris, sediment, and silt that escapes the bulkhead.
Pile driving and dredging activities may re-suspend disturbed
sediment and result in turbid conditions within the immediate project
area. Suspended sediments may be transported and re-deposited
downstream of the prevailing currents, which could increase siltation
in the vicinity of the Shipyard. Resulting sedimentation is also
expected to be localized and temporary. Since the currents are so
strong in the area, suspended sediments in the water column should
dissipate and quickly return to background levels. Following the
completion of sediment-disturbing activities, the turbidity levels
within the temporary offshore workspace are expected to return to
normal ambient levels following the end of construction in all
construction scenarios. Turbidity within the water column has the
potential to reduce the level of oxygen in the water and irritate the
gills of cetacean or pinniped prey fish species in the project area.
However, turbidity plumes associated with the project would be
temporary and localized, and fish in the project area would be able to
move away from and avoid the areas where plumes may occur. Therefore,
it is expected that the impacts on prey fish species from turbidity,
and therefore on marine mammals, would be minimal and temporary. In
general, the area likely impacted by the project is relatively small
compared to the available habitat in Great Bay Estuary. As a result,
activity at the project site would be inconsequential in terms of its
effects on marine mammal foraging.
In summary, given the short daily duration of sound associated with
individual pile driving events and the relatively small areas being
affected, pile driving activities associated with the proposed action
are not likely to have a permanent, adverse effect on any fish habitat,
populations of fish species or marine mammal foraging habitat at the
project area. Furthermore, any impacts to marine mammal habitat that
may occur are not expected to cause significant or long-term
consequences for individual marine mammals or their populations.
Proposed Mitigation Measures
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, ``and other means of effecting the least practicable impact
on such species or stock and its habitat, paying particular attention
to rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking'' for certain
subsistence uses. NMFS regulations require applicants for incidental
take authorizations to include information about the availability and
feasibility (economic and technological) of equipment, methods, and
manner of conducting such activity or other means of effecting the
least practicable adverse impact upon the affected species or stocks,
their habitat. 50 CFR 216.104(a)(11). For the proposed project, the
Navy worked with NMFS and proposed the following mitigation measures to
minimize the potential impacts to marine mammals in the project
vicinity. The primary purposes of these mitigation measures are to
minimize sound levels from the activities, and to monitor marine
mammals within designated zones of influence corresponding to NMFS'
current Level A and B harassment thresholds which are depicted in Table
9 found later in the Estimated Take by Incidental Harassment section.
In addition to the measures described later in this section, the
Navy would employ the following standard mitigation measures:
Time Restrictions--Pile driving/removal (vibratory as well as
impact), drilling, and vibratory extraction will only be conducted
during daylight hours.
Establishment of Shutdown Zone--During pile driving and removal,
the shutdown zone shall include all areas where the underwater SPLs are
anticipated to equal or exceed the Level A (injury) harassment criteria
for marine mammals (180 dB rms isopleth for cetaceans; 190 dB rms
isopleth for pinnipeds). During all pile driving and removal
activities, regardless of predicted SPLs, the entire Level A zone, or
shutdown zone, will be monitored to prevent injury to marine mammals
from their physical interaction with construction equipment during in-
water
[[Page 52625]]
activities. Pile driving or removal operations will cease if a marine
mammal approaches the zone. Pile driving/removal operations will
restart once the marine mammal is visibly seen leaving the Level A
zone, or after 15 minutes have passed with no sightings
During all in-water construction or demolition activities having
the potential to affect marine mammals, a shutdown zone of 10 m will be
implemented to ensure marine mammals are not present within this zone.
These activities could include, but are not limited to: (1) Pile
driving and removal and the the removal of a pile from the water
column/substrate via a crane (i.e., a ``dead pull''). These
precautionary measures would also further reduce the possibility of
auditory injury and behavioral impacts as well as limit the unlikely
possibility of injury from direct physical interaction with
construction operations. For in-water heavy machinery work other than
pile driving (using, e.g., standard barges, tug boats), if a marine
mammal comes within 10 m, operations shall cease and vessels shall
reduce speed to the minimum level required to maintain steerage and
safe working conditions.
Establishment of Disturbance Zone or Zone of Influence--Disturbance
zones or zones of influence (ZOI) are the areas in which SPLs equal or
exceed 160 dB rms for impact driving and 120 dB rms for vibratory
driving. Disturbance zones provide utility for monitoring conducted for
mitigation purposes (i.e., shutdown zone monitoring) by establishing
monitoring protocols for areas adjacent to the shutdown zones.
Monitoring of disturbance zones enables observers to be aware of and
communicate the presence of marine mammals in the project area but
outside the shutdown zone and thus prepare for potential shutdowns of
activity. However, the primary purpose of disturbance zone monitoring
is for documenting incidents of Level B harassment; disturbance zone
monitoring is discussed in greater detail later (see ``Proposed
Monitoring and Reporting''). Nominal radial distances for disturbance
zones are shown in Table 9 in this Notice. Due to the increased costs
associated with monitoring the entire Level B zone, or buffer zone, the
zone will be monitored during two-thirds of all pile driving days. If a
marine mammal is observed entering the buffer zone, an exposure would
be recorded and behaviors documented. The Navy will extrapolate data
collected during monitoring days and extrapolate and calculate total
takes for all pile driving days.
All shutdown and disturbance zones will initially be based on the
distances from the source that were predicted for each threshold level.
Soft Start--The use of a soft start procedure is believed to
provide additional protection to marine mammals by providing a warning
and/or giving marine mammals a chance to leave the area prior to the
hammer operating at full capacity. The Navy will use soft-start
techniques (ramp-up/dry fire) recommended by NMFS for impact driving.
Soft start must be conducted at beginning of day's activity and at any
time pile driving has ceased for more than 30 minutes. For impact
hammer driving, contractors are required to provide an initial set of
three strikes from the impact hammer at 40 percent energy, followed by
a 30-second waiting period, then two subsequent 3-strike sets. The 30-
second waiting period is proposed based on the Navy's recent experience
and consultation with NOAA Fisheries Service on a similar project at
Naval Base Kitsap at Bangor (Department of the Navy 2010).
Monitoring Protocols
Visual Marine Mammal Observation--The Navy will collect sighting
data and behavioral responses to construction for marine mammal species
observed in the region of activity during the period of activity. All
observers will be trained in marine mammal identification and behaviors
and are required to have no other construction-related tasks while
conducting monitoring. The Navy will monitor the shutdown zone and
disturbance zone before, during, and after pile driving, with observers
located at the best practicable vantage points. Based on NMFS
requirements, the Marine Mammal Monitoring Plan would implement the
following procedures for pile driving and removal:
Impact Installation: Monitoring will be conducted within
the Level A harassment shutdown zone during all pile driving operations
and the Level B harassment buffer zone during two-thirds of pile
driving days. Monitoring will take place from 15 minutes prior to
initiation through 30 minutes post-completion of pile driving/removal
activities.
A minimum of two marine mammal observers (MMOs) will be in
place during all pile-driving/removal operations. MMOs designated by
the contractor will be placed at the best vantage point(s) practicable
to monitor for marine mammals and implement shutdown/delay procedures
when applicable by calling for the shutdown to equipment operators. The
MMOs shall have no other construction-related tasks while conducting
monitoring and will be trained on the observation zones, species
identification, how to observe, and how to fill out the data sheets by
the Navy Natural Resources Manager prior to any pile driving
activities.
The Navy shall conduct a pre-construction briefing with
the contractor. During the briefing, all contractor personnel working
in the Project area will watch the Navy's Marine Species Awareness
Training video. An informal guide will be included with the monitoring
plan to aid in identifying species if they are observed in the vicinity
of the Project area.
Prior to the start of pile driving/removal activity, the
shutdown and safety zones will be monitored for 15 minutes to ensure
that they are clear of marine mammals. Pile driving will only commence
once observers have declared the shutdown zone clear of marine mammals;
animals will be allowed to remain in the disturbance zone and their
behavior will be monitored and documented.
In the unlikely event of conditions that prevent the
visual detection of marine mammals, such as heavy fog, activities with
the potential to result in Level A or Level B harassment will not be
initiated. Pile driving would be curtailed, but vibratory pile driving
or extraction would be allowed to continue if such conditions arise
after the activity has begun.
The waters will continue to be scanned for at least 30
minutes after pile driving has completed each day.
Mitigation Conclusions
NMFS has carefully evaluated the applicant's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that NMFS prescribes the means of affecting the least
practicable impact on the affected marine mammal species and stocks and
their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another:
The manner in which, and the degree to which, the
successful implementation of the measure is expected to minimize
adverse impacts to marine mammals;
The proven or likely efficacy of the specific measure to
minimize adverse impacts as planned; and
The practicability of the measure for applicant
implementation.
Any mitigation measure(s) prescribed by NMFS should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current
[[Page 52626]]
science), or contribute to the accomplishment of one or more of the
general goals listed below:
1. Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
2. A reduction in the numbers of marine mammals (total number or
number at biologically important time or location) exposed to received
levels of pile driving, or other activities expected to result in the
take of marine mammals (this goal may contribute to 1, above, or to
reducing harassment takes only).
3. A reduction in the number of times (total number or number at
biologically important time or location) individuals would be exposed
to received levels of pile driving, or other activities expected to
result in the take of marine mammals (this goal may contribute to 1,
above, or to reducing harassment takes only).
4. A reduction in the intensity of exposures (either total number
or number at biologically important time or location) to received
levels of pile driving, or other activities expected to result in the
take of marine mammals (this goal may contribute to a, above, or to
reducing the severity of harassment takes only).
5. Avoidance or minimization of adverse effects to marine mammal
habitat, paying special attention to the food base, activities that
block or limit passage to or from biologically important areas,
permanent destruction of habitat, or temporary destruction/disturbance
of habitat during a biologically important time.
6. For monitoring directly related to mitigation--an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, our preliminarily
determination is that the proposed mitigation measures provide the
means of effecting the least practicable impact on marine mammals
species or stocks and their habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance.
Proposed Monitoring and Reporting
In order to issue an ITA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth, ``requirements pertaining to
the monitoring and reporting of such taking.'' The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs
must include the suggested means of accomplishing the necessary
monitoring and reporting that will result in increased knowledge of the
species and of the level of taking or impacts on populations of marine
mammals that are expected to be present in the proposed action area.
The Navy submitted a marine mammal monitoring plan as part of the IHA
application. It can be found in Section 13 of the application. http://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Monitoring measures prescribed by NMFS should accomplish one or
more of the following general goals:
1. An increase in the probability of detecting marine mammals, both
within the mitigation zone (thus allowing for more effective
implementation of the mitigation) and in general to generate more data
to contribute to the analyses mentioned below;
2. An increase in our understanding of how many marine mammals are
likely to be exposed to levels of pile driving that we associate with
specific adverse effects, such as behavioral harassment, TTS, or PTS;
3. An increase in our understanding of how marine mammals respond
to stimuli expected to result in take and how anticipated adverse
effects on individuals (in different ways and to varying degrees) may
impact the population, species, or stock (specifically through effects
on annual rates of recruitment or survival) through any of the
following methods:
[ssquf] Behavioral observations in the presence of stimuli compared
to observations in the absence of stimuli (need to be able to
accurately predict received level, distance from source, and other
pertinent information);
[ssquf] Physiological measurements in the presence of stimuli
compared to observations in the absence of stimuli (need to be able to
accurately predict received level, distance from source, and other
pertinent information);
[ssquf] Distribution and/or abundance comparisons in times or areas
with concentrated stimuli versus times or areas without stimuli;
4. An increased knowledge of the affected species; and
5. An increase in our understanding of the effectiveness of certain
mitigation and monitoring measures.
Acoustic Monitoring
The Navy will implement in situ acoustic monitoring efforts to
measure SPL from in-water construction activities. The Navy will
collect and evaluate acoustic sound record levels for 10 percent of the
pile-driving activities conducted, sufficient to confirm measured
contours associated with the acoustic ZOIs. Acoustic sound recordings
will be collected sufficient to document sound source levels for 10
percent of the proposed piles to be driven and extracted. The Navy will
conduct acoustic monitoring at the source (33 feet) and, where the
potential for Level A harassment exists, at a second representative
monitoring location at an intermediate distance between the cetacean
and pinniped shutdown zones. In conjunction with measurements of SPLs
at the source and shutdown monitoring locations, there will also be
intermittent verification for impact driving or pile driving and
extraction to determine the actual distance to either the 120 dB re
1[mu]Pa rms isopleth or the point at which the SPL (maximum rms) from
the equipment diminishes to the median ambient SPL (rms) and hence
becomes indistinguishable. Acoustic measurements will continue during
subsequent years of in-water construction for the Project.
Visual Marine Mammal Observations
The Navy will collect sighting data and behavioral responses to
construction for marine mammal species observed in the region of
activity during the period of construction. All observers will be
trained in marine mammal identification and behaviors. NOAA Fisheries
Service requires that the observers have no other construction-related
tasks while conducting monitoring.
The Navy will monitor the shutdown zone and safety zone before,
during, and after pile driving activities. Based on NOAA Fisheries
Service requirements, the Marine Mammal Monitoring Plan would include
the following procedures:
MMOs will be primarily located on boats, docks, and piers
at the best vantage point(s) in order to properly see the entire shut
down zone(s);
MMOs will be located at the best vantage point(s) to
observe the zone associated with behavioral impact thresholds;
During all observation periods, observers will use
binoculars and the naked eye to search continuously for marine mammals;
Monitoring distances will be measured with range finders;
Distances to animals will be based on the best estimate of
the MMO, relative to known distances to objects in the vicinity of the
MMO;
Bearing to animals will be determined using a compass; and
[[Page 52627]]
Pile driving activities will be curtailed under conditions
of fog or poor visibility that might obscure the presence of a marine
mammal within the shutdown zone;
Post-Activity Monitoring
Monitoring of the shutdown and disturbance zones will continue for
30 minutes following the completion of the activity.
Data Collection
MMOs will use NMFS' approved data forms. Among other pieces of
information, the Navy will record detailed information about any
implementation of shutdowns, including the distance of animals to the
pile and description of specific actions that ensued and resulting
behavior of the animal, if any. At a minimum, the following information
would be collected on the sighting forms:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
Weather parameters (e.g., percent cover, visibility);
Water conditions (e.g., sea state, tide state);
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any observable marine mammal behavior
patterns, including bearing and direction of travel and distance from
pile driving activity;
Distance from pile driving activities to marine mammals
and distance from the marine mammals to the observation point;
Locations of all marine mammal observations; and
Other human activity in the area.
Reporting Measures
The Navy would provide NMFS with a draft monitoring report within
60 days prior to any subsequent authorization, whichever is sooner. A
monitoring report is required before another authorization can be
issued to the Navy. This report will detail the monitoring protocol,
summarize the data recorded during monitoring, and estimate the number
of marine mammals that may have been harassed. If no comments are
received from NMFS within 30 days, the draft final report will
constitute the final report. If comments are received, a final report
must be submitted within 30 days after receipt of comments. The report
should include data and information listed in Section 13.3 of the
application.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury, serious injury or mortality (e.g.,
ship-strike, gear interaction, and/or entanglement), the Navy shall
immediately cease the specified activities and report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources, NMFS, and the Northeast/Greater Atlantic Regional Stranding
Coordinator. The report would include the following information:
Time, date, and location (latitude/longitude) of the
incident;
Name and type of vessel involved;
Vessel's speed during and leading up to the incident;
Description of the incident;
Status of all sound source use in the 24 hours preceding
the incident;
Water depth;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS would work with the Navy to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. The Navy would not be able
to resume their activities until notified by NMFS via letter, email, or
telephone.
In the event that the Navy discovers an injured or dead marine
mammal, and the lead MMO determines that the cause of the injury or
death is unknown and the death is relatively recent (i.e., in less than
a moderate state of decomposition as described in the next paragraph),
the Navy would immediately report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
and the Greater Atlantic Regional Stranding Coordinator. The report
would include the same information identified in the paragraph above.
Activities would be able to continue while NMFS reviews the
circumstances of the incident. NMFS would work with the Navy to
determine whether modifications in the activities are appropriate.
In the event that the Navy discovers an injured or dead marine
mammal, and the lead MMO determines that the injury or death is not
associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), The Navy would report the incident
to the Chief of the Permits and Conservation Division, Office of
Protected Resources, NMFS, and the Greater Atlantic Regional Stranding
Coordinator within 24 hours of the discovery. The Navy would provide
photographs or video footage (if available) or other documentation of
the stranded animal sighting to NMFS and the Marine Mammal Stranding
Network.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here,
section 3(18) of the MMPA defines ``harassment'' as: ``any act of
pursuit, torment, or annoyance which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild [Level A harassment];
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering [Level B harassment].''
All anticipated takes would be by Level B harassment resulting from
pile driving and are likely to involve temporary changes in behavior.
Physical injury or lethal takes are not expected due to the expected
source levels and sound source characteristics associated with the
activity, and the proposed mitigation and monitoring measures are
expected to further minimize the possibility of such take.
Given the many uncertainties in predicting the quantity and types
of impacts of sound on marine mammals, it is common practice to
estimate how many animals are likely to be present within a particular
distance of a given activity, or exposed to a particular level of
sound, where NMFS believes take is likely.
The Navy has requested authorization for the incidental taking of
small numbers of harbor porpoise, harbor seal, gray seal, hooded seal
and harp seal that may result from vibratory and impact pile driving
and removal during activities associated with the waterfront
improvement project.
In order to estimate the potential incidents of take that may occur
incidental to the specified activity, we must first estimate the extent
of the sound field that may be produced by the activity and then
consider in combination with information about marine mammal density or
abundance in the project area. We first provide information on
applicable sound thresholds for determining effects to marine mammals
before describing the
[[Page 52628]]
information used in estimating the sound fields, the available marine
mammal density or abundance information, and the method of estimating
potential incidences of take.
Sound Thresholds
We use generic sound exposure thresholds to determine when an
activity that produces sound might result in impacts to a marine mammal
such that a take by harassment might occur. To date, no studies have
been conducted that explicitly examine impacts to marine mammals from
pile driving sounds or from which empirical sound thresholds have been
established. These thresholds (Table 4) are used to estimate when
harassment may occur (i.e., when an animal is exposed to levels equal
to or exceeding the relevant criterion) in specific contexts; however,
useful contextual information that may inform our assessment of effects
is typically lacking and we consider these thresholds as step
functions. NMFS is working to revise these acoustic guidelines; for
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
Table 4--Underwater Injury and Disturbance Threshold Decibel Levels for
Marine Mammals
------------------------------------------------------------------------
Criterion Criterion definition Threshold *
------------------------------------------------------------------------
Level A harassment.......... PTS (injury) **......... 190 dB RMS for
pinnipeds.
180 dB RMS for
cetaceans.
Level B harassment.......... Behavioral disruption 160 dB RMS.
for impulse noise
(e.g., impact pile
driving).
Level B harassment.......... Behavioral disruption 120 dB RMS.***
for non-pulse noise
(e.g., vibratory pile
driving, drilling).
------------------------------------------------------------------------
* All decibel levels referenced to 1 micropascal (re: 1 [mu]Pa). Note
all thresholds are based off root mean square (RMS) levels.
** PTS = Permanent Threshold Shift conservatively based on TTS
(Temporary Threshold Shift) Distance to Sound Thresholds.
Underwater Sound Propagation Formula--Pile driving generates
underwater noise that can potentially result in disturbance to marine
mammals in the project area. Transmission loss (TL) is the decrease in
acoustic intensity as an acoustic pressure wave propagates out from a
source. TL parameters vary with frequency, temperature, sea conditions,
current, source and receiver depth, water depth, water chemistry, and
bottom composition and topography. This formula neglects loss due to
scattering and absorption, which is assumed to be zero here. The degree
to which underwater sound propagates away from a sound source is
dependent on a variety of factors, most notably the water bathymetry
and presence or absence of reflective or absorptive conditions
including in-water structures and sediments.
Cylindrical spreading occurs in an environment in which sound
propagation is bounded by the water surface and sea bottom, resulting
in a reduction of 3 dB in sound level for each doubling of distance
from the source. The formula for practical spreading transmission loss
is TL = 10 log10 (R/10), where R is the distance from the source
assuming the near source levels are measured at 10 meters (33 feet).
This transmission loss model was used for piles being driven in a water
depth less than approximately 3 meters (10 feet). Specifically, the
model was used for the 14-inch H-type (sister) piles that would be
driven using an impact hammer at Rail Beam 1 at Berth 11,12, and 13.
A practical spreading value of fifteen is often used in the absence
of reliable data and under conditions where water increases with depth
as the receiver moves away from the shoreline, resulting in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions. Practical spreading loss (4.5 dB
reduction in sound level for each doubling of distance) was used in
water depths ranging from 3 meters to 15 meters which is the greatest
depth at which pile driving activities will take place for this
project. The formula for cylindrical spreading transmission loss is TL
= 15 log10 (R/10), where R is the distance from the source assuming the
near source levels are measured at 10 meters (33 feet).
This transmission loss model was used for the piles being driven
(or drilled) in water depths of between approximately 10 and 50 feet.
These pile types and sizes included:
25-inch steel sheet piles, which would be driven using a
vibratory hammer at Berth 11.
14-inch steel H-type piles, which would be driven using an
impact hammer at Berth 11during trestle alignment and construction.
15-inch timber piles, which would be installed using a
vibratory hammer to reconstruct timber dolphins at the corner of Berths
11 and 12.
36-inch steel H-type (king) piles at Berth 11 which would
be drilled and rock-socketed into the bedrock.
This model was also used for piles extracted in water depths of 10
to 50 feet and included:
14-inch steel H-type piles, which would be used to align
and construct the trestle that would be extracted using a vibratory
hammer at Berth 11.
15-inch timber fender piles, which would be extracted
using a vibratory hammer at Berth 11 and the timber dolphin at the
corners of Berths 11 and 12.
Source levels for the two pile driving methods that are proposed
for use during the project were obtained from the ``Compendium of Pile
Driving Sound Data,'' which is included as Appendix I to ``Technical
Guidance for Assessment and Mitigation of the Hydroacoustic Effects of
Pile Driving on Fish'' (ICF Jones & Stokes and Illingworth & Rodkin,
Inc. 2012). The information presented in the compendium is a
compilation of sound pressure levels recorded during various in-water
pile driving projects in California, Oregon, Washington, and Nebraska.
The compendium is a commonly used reference document for pile driving
source levels when analyzing impacts on protected species, including
marine mammals, from pile driving activities.
Source levels were collected for the four types of piles that would
be installed and two pile driving methods proposed for the project:
14-inch steel H-type piles will be used as sister piles to
align and construct the trestle; installed via impact hammer.
15-inch timber piles will be used for re-installation of
dolphins and installed via vibratory hammer.
25-inch steel sheet piles will be used for the bulkhead at
Berth 11 and installed via vibratory hammer.
Reference source levels for the Project were determined using data
for piles of similar sizes, the same pile driving method as that
proposed for the Project, and at similar water depths. While the
[[Page 52629]]
pile sizes and water depths chosen as proxies do not exactly match
those for the Project, they are the closest matches available, and it
is assumed that the source levels shown in Table 5 and 6 are the most
representative for each pile type and associated pile driving method.
Table 5--Source Levels for In-Water Impact Hammer 14-Inch Steel H-Type (Sister) Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Distance
Pile size and pile type Water measured Peak (dB) RMS (dB) SEL (dB) Location
depth (m) (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-inch Steel H-type pile--Thick.......... 5 10 200 183 170 CA (Specific location unknown).
15-inch Steel H-type pile--Thick.......... 3 10 195 180 170 Ballena Isle Marina, Alameda, CA, San Francisco Bay.
12- to 15-inch H-type pile--Thick 4 10 198 182 170 .....................................................
(Average).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: ICF Jones & Stokes and Illingworth & Rodkin, Inc. 2012.
Note: All source levels are referenced to 1 microPascal (re 1 [micro]Pa).
\1\ As printed in source material.
Key: dB = decibel; m = meter; RMS = root mean square; SEL = sound exposure level.
Table 6--Source Levels for In-Water Vibratory Hammer 25-Inch Steel Sheet Piles, 20-Inch Steel Sheet Piles and 15-Inch Timber Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Distance
Pile size and pile type Water measured Peak (dB) RMS (dB) SEL (dB) Location
depth (m) (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch AZ * Steel Sheet \1\.............. 15 10 177 163 162 Berth 23, Port of Oakland, CA.
24-inch AZ Steel Sheet \1\................ 15 10 175 162 162 Berth 30, Port of Oakland, CA.
24-inch AZ Steel Sheet \1\................ 15 10 177 163 163 Berth 35/37 Port of Oakland, CA.
24-inch AZ Steel Sheet--Typical \1\....... 15 10 175 160 160 CA (Specific location unknown).
24-inch AZ Steel Sheet--Loudest \1\....... 15 10 182 165 165 CA (Specific location unknown).
24-inch AZ Steel Sheet (Average) \1\...... 15 10 178 163 163 .....................................................
15-inch Timber Pile \2\................... 10 16 164 150 NP WSF Port Townsend Ferry Terminal, WA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source:
\1\ ICF Jones & Stokes and Illingworth & Rodkin, Inc. 2012.
\2\ WSDOT 2010.
The exact source level for a given pile and pile driving method
largely depends not only on the pile size and water depth but also on
site-specific conditions such as environmental and physical factors,
including water temperature and sediment composition. Therefore, in
this analysis, several source levels for each pile type and associated
pile driving method were averaged when multiple levels were available.
These averaged source levels were used as inputs to determine
transmission loss, which, in turn, was used in the propagation models
described above.
Drilling
Drilling is considered an intermittent, non-impulsive noise source,
similar to vibratory pile driving. Very little information is available
regarding source levels of in-water drilling activities associated with
nearshore pile installation such as that proposed for the Berths 11,
12, and 13 structural repairs project. Dazey et al., (2012) attempted
to characterize the source levels of several marine pile-drilling
activities. One such activity was auger drilling (including
installation and removal of the associated steel casing). The average
sound pressure levels re 1 [mu]Pa RMS were displayed for casing
installation, auger drilling (inside the casing), and casing removal.
For the purposes of this plan, it is assumed that the casing
installation and removal activities would be conducted in a manner
similar to that described in Dazey et al., (2012), primarily via
oscillation. These average source levels are reported in Table 7.
Table 7--Average Source Levels for Auger Drilling Activities During Pile Installation
----------------------------------------------------------------------------------------------------------------
Water depth Distance
Drilling activity (m) measured (m) RMS (dB) Location
----------------------------------------------------------------------------------------------------------------
Casing Installation................... 1-5 1 157 Bechers Bay Santa Rosa
Island, CA.
Auger Drilling........................ 1-5 1 151 Bechers Bay Santa Rosa
Island, CA.
Casing Removal........................ 1-5 1 152 Bechers Bay Santa Rosa
Island, CA.
----------------------------------------------------------------------------------------------------------------
Source: Dazey et al., 2012.
Note: All source levels are referenced to 1 microPascal (re 1 [micro]Pa).
IHA applications for other construction projects have reported
that, due to a lack of information regarding pile drilling source
levels, it is generally assumed that pile drilling would produce less
in-water noise than both impact and vibratory pile driving. Based on
the general lack of information about these activities and the
assumption that in-water noise from pile drilling would be less than
either impact or vibratory pile driving, it is assumed that the
[[Page 52630]]
source levels presented in Table 7 are the most applicable for acoustic
impact analysis at Berths 11, 12, and 13. For the purposes of this
proposed IHA we will conservatively assume that drilling has similar
source levels as vibratory driving when calculating zones of
influences.
Pile Extraction
Vibratory pile extraction is considered an intermittent, non-
impulsive noise source. Little information is available specific to
vibratory extraction for most types of piles. The source level for
timber-pile extraction was obtained from ``Port Townsend Test Pile
Project: Underwater Noise Monitoring Draft Final Report,'' prepared by
Jim Loughlin for the Washington State Department of Transportation
Office of Air Quality and Noise (WSDOT 2010) and is shown in Table 8.
Source levels for vibratory extraction of H-type piles were
obtained from ``Underwater Acoustic Measurements of Vibratory Pile
Driving at the Pipeline 5 Crossing in the Snohomish River, Everett,
Washington,'' prepared by Greeneridge Science, Inc., for the City of
Everett (Burgess et al., 2005).
For vibratory pile extraction of the 24-inch steel sheet piles
(used as a proxy for the 20-inch steel sheet piles that would be
extracted at the circular, cellular cofferdam), the average value for
the vibratory installation source levels from Table 6 was used. Sources
including ICF Jones & Stokes and Illingworth & Rodkin, Inc. (2012)
report the same values for vibratory installation and extraction,
assuming that the two activities would produce similar source levels if
water depth, pile size, and equipment remain constant.
Reference source levels for the project were determined using data
for piles of similar size, the same extraction method as that proposed
for the project, and at similar water depths. While the pile sizes and
water depths chosen as proxies do not exactly match those for the
project, they are the closest matches available, and it is assumed that
the source levels shown in Table 8 and are representative of the
vibratory pile extraction method used for the project.
Table 8--Average Source Level for Vibratory Pile Extraction 15-Inch Timber Fender Piles \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Distance
Pile size and pile type Water depth (m) measured (m) Peak (dB) RMS (dB) Location
--------------------------------------------------------------------------------------------------------------------------------------------------------
15-inch Timber Fender Pile \2\.................. 10m 16m 164 150 WSF Port, Townsend Ferry Terminal,
WA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ All source levels are referenced to 1 microPascal (re 1 [mu]Pa).
\2\ WSDOT 2010.
Zones of Influence
Attenuation distances to the NOAA Fisheries thresholds for Level B
takes for pile driving are described in Table 9. These attenuation
distances have been developed using the propagation models described
above. Modeling was performed for each driving, drilling, installing,
and removing activity described above using the depth-appropriate
model. Activities that would result in the longest attenuation
distances were selected as the worst-case sound exposure distances that
would determine the ZOI for each project location.
Table 9--Pile Driving Sound Exposure Distances
[In-water]
----------------------------------------------------------------------------------------------------------------
Behavioral thresholds
Drilling activity for cetaceans and Propagation model Attenuation distance
pinnipeds to threshold
----------------------------------------------------------------------------------------------------------------
Vibratory Hammer..................... 120 dB RMS............. Practical Spreading 4.57 mi (7.35 km).
Loss (3 m to 15 m
water depth).
Impact Hammer........................ 160 dB RMS............. Cylindrical Spreading 0.984 mi (1.58 km).
Loss (<3 m water
depth).
----------------------------------------------------------------------------------------------------------------
Note: All source levels are referenced to 1 microPascal (re 1 [mu]Pa).
During vibratory hammer operation modeled sound would attenuate to
120 dB at approximately 4.57 miles from the Berth 11 Structural Repairs
Project. During operation of the impact hammer, modeled sound would
attenuate to 160 dB at approximately 0.98 miles from the Berths 11
Structural Repairs Project site. Note that these attenuation distances
are based on sound characteristics in open water. The Project area is
located in a river surrounded by topographic features and not in open
water; therefore, given the numerous land features and islands within
the vicinity of the Project sites in the Piscataqua River, these
attenuation distances are extremely conservative.
No Level A takes are expected because attenuation out to the
pinniped injury threshold of 190 dB rms is calculated at 5 feet (1.58
meters), and attenuation out to the 180 dB RMS injury threshold for
cetaceans is calculated at 52 feet (15.8 meters). These very small
areas can easily be monitored for marine mammals, and mitigative
measures would be implemented to ensure that no Level A takes occur.
The ZOIs for each of the two separate sound sources (impact driving
and vibratory driving/drilling) at Berth 11 are shown on Figure 6-1 in
the application. Work would occur in phases over several years. All of
the construction-related in-water sound occurring within the waters of
these ZOIs would exceed the designated NOAA Fisheries thresholds for
behavioral take. The ZOIs were used to calculate potential takes from
each sound source and would be monitored during in-water work at Berth
11 to estimate actual harassment takes of marine mammals. The total
area ensonified by these two sources is 0.36 square miles (mi\2\)
(233.4 acres).
[[Page 52631]]
The numerous topographic features present in and along the
Piscataqua River would greatly limit the area that would be impacted
from in-water sound. Sound from either source would be truncated with
minimal attenuation. Due to the numerous islands and other land
features at and around the site, the actual ZOIs for both the vibratory
hammer and impact hammer are identical even though the calculated ZOIs
are different. This is illustrated in Figure 6-1 in the Application.
No sound is expected to fully attenuate to the 120-decibel
threshold for vibratory pile driving because topographic features (e.g.
islands, shorelines) in the river would prevent attenuation to the full
distance of 4.57 miles. Very little sound would reach the 160 dB
threshold at the full distance of 0.984 miles for the impact hammer due
to these same sound-blocking topographical features. The longest
attenuation distance from the Berth 11 Project site would occur to the
southeast where, during impact pile driving, sound would attenuate
through the waters east of Pierce Island to the 160 dB threshold (a
distance of 0.88 miles) at Goat Island (See Figure 6-1 in application).
The actual ZOI used to estimate exposure excludes water areas blocked
by topographical features.
Airborne Exposure
Airborne transmission loss was calculated using the spherical
spreading model above. Using this model, the greatest possible
distances to airborne harassment thresholds were estimated, using a
source level of 111 dB 20 [mu]Pa rms for 24'' round steel piles, as
552.5 ft (168.3 m) to the 90 dB threshold for harbor seals and 174.5 ft
(53.2 m) to the 100 dB threshold for all other seals. Other types of
pile driving and extraction that would occur during the project would
generate lower airborne sound pressures, with smaller distances and
areas of potential disturbance, and for that reason are not considered
further in this application. Since protective measures are in place out
to the distances calculated for the underwater Level B thresholds, the
distances for the airborne thresholds will be effectively covered by
monitoring. The closest known haul-out site for seals within the
Piscataqua River is 1.5 miles (2414 m) downstream of the Project area
while the attenuation distance to the 90 dB threshold is 0.108 miles
(174.5 m) and the 100 dB threshold is 0.033 miles (53.2 m). While there
are no documented haul-outs, animals do occasionally haul-out on nearby
rocks/jetties and could be flushed into the water. However, it is
assumed that any hauled out animals within the disturbance zone will
also enter the water and be exposed to underwater noise. Therefore,
acoustic disturbance to pinniped resulting from airborne sound from
pile driving and drilling are not considered further in this
application.
The take calculations presented here relied on the best data
currently available for marine mammal populations within close
proximity to the Piscataqua River. There are not population data for
any marine mammal species specifically within the Piscataqua River;
however, the population data used are from the most recent NMFS Stock
Assessment Reports (SAR) for the Atlantic Ocean. The most recent SAR
population number was used for each species. The specific SAR used is
discussed within each species take calculation in Sections 6.6.1
through 6.6.5 of the application. The formula was developed for
calculating take due to pile driving, extraction, and drilling and
applied to the species-specific noise-impact threshold. The formula is
founded on the following assumptions:
All piles to be installed would have a noise disturbance
distance equal to the pile that causes the greatest noise disturbance.
Pile driving could potentially occur every day of the in-
water work window; however, it is estimated no more than a few hours of
pile driving would occur per day.
An individual can only be taken once per day due to sound
from pile driving, whether from impact or vibratory pile driving, or
vibratory extraction
The conservative assumption is made that all pinnipeds within the
ZOI would be underwater during at least a portion of the noise
generating activity and, hence, exposed to sound at the predicted
levels.
The calculation for marine mammal takes is estimated by:
Take estimate = (n * ZOI) * X days of total activity
Where:
n = density estimate used for each species
X = number of days of pile driving, estimated based on the total
number of piles and the average number of piles that the contractor
can install per day.
ZOI = noise threshold zone of influence (ZOI) impact area
The calculation n * ZOI produces an estimate of the abundance of
animals that could be present in the area of exposure per day. The
abundance is then multiplied by the total number of days of pile
driving to determine the take estimate. Because the estimate must be a
whole number, this value was rounded up.
The ZOI impact area is the estimated range of impact on marine
mammals during in-water construction. The ZOI is the area in which in-
water sound would exceed designated NOAA Fisheries Service thresholds.
The formula for determining the area of a circle ([pi] * radius\2\) was
used to calculate the ZOI around each pile, for each threshold. The
distances specified were used for the radius in the equation. The ZOI
impact area does not encompass landforms that may occur within the
circle. The ZOI also took into consideration the possible affected area
of the Piscataqua River from the furthest pile driving/extraction site
with attenuation due to land shadowing from islands in the river as
well as the river shoreline.
Harbor Porpoise
Harbor porpoises may be present in the Project area during spring,
summer, and fall, from April to December. Based on density data from
the Navy Marine Species Density Database, their presence is highest in
spring, decreases in summer, and slightly increases in fall. However,
in general, porpoises are known to occasionally occur in the river.
Average density for the predicted seasons of occurrence was used to
determine abundance of animals that could be present in the area for
exposure, using the equation abundance = n * ZOI. Estimated abundance
estimate for harbor porpoises was 0.90 animals generated from the
equation (0.9445 km\2\ * 0.9578 animals/km\2\). Therefore, the number
of Level B harbor porpoises exposures within the ZOIs is (72 days *
0.90 animals/day) which equals 65 animals. Therefore, the total
requested harbor seal takes is 65.
Gray Seal
Gray seals may be present year-round in the project vicinity, with
constant densities throughout the year. Gray seals are less common in
the Piscataqua River than the harbor seal. Average density for the
predicted seasons of occurrence was used to determine abundance of
animals that could be present in the area for exposure, using the
equation abundance = n * ZOI. Estimated abundance for gray seals was
0.21/day generated from the equation (0.9445 km\2\ * 0.2202 animals/
km\2\). The number of Level B harbor porpoises exposures within the
ZOIs is (72 days * 0.21 animals/day) resulting in up to 15 Level B
exposures of gray seals within the ZOIs. Total requested gray seal
takes is 15.
[[Page 52632]]
Harbor Seal
Harbor seals may be present year-round in the project vicinity,
with constant densities throughout the year. Harbor seals are the most
common pinniped in the Piscataqua River near the Shipyard. Average
density for the predicted seasons of occurrence was used to determine
abundance of animals that could be present in the area for exposure,
using the equation abundance = n * ZOI. Abundance for harbor seals was
0.19/day generated from the equation (0.9445 km\2\ * 0.1998 animals/
km\2\). The number of Level B harbor seal exposures within the ZOIs is
(72 days * 0.19 animals/day) resulting in 14 harbor seals. Therefore,
total requested harbor seal takes is 14.
Harp Seal
Harp seals may be present in the Project vicinity during the winter
and spring, from January through February. In general, harp seals are
much rarer than the harbor seal and gray seal in the Piscataqua River.
Average density for the predicted seasons of occurrence was used to
determine abundance of animals that could be present in the area for
exposure, using the equation abundance = n * ZOI. Abundance for harp
seals was 0.012/day generated from the equation (0.9445 km\2\ * 0.0125
km\2\). The number of Level B harp seal exposures within the ZOI is (72
days * 0.012 animals/day) resulting in one Level B exposure. Therefore,
the total requested harp seal takes is 1.
Hooded Seal
Hooded seals may be present in the project vicinity during the
winter and spring, from January through May, though their exact
seasonal densities are unknown. In general, hooded seals are much rarer
than the harbor seal and gray seal in the Piscataqua River. Anecdotal
sighting information indicates that two hooded seals were observed from
the Shipyard in August 2009, but no other observations have been
recorded (Trefry November 20, 2015). Average density for the predicted
seasons of occurrence was used to determine abundance of animals that
could be present in the area for exposure. Since the average density
for hooded seals is unknown and the animal is described as being rare,
no authorized take of hooded seals is requested.
The total numbers of takes proposed for the five marine mammal
species that may occur within the Navy's project area during the
duration of proposed in-water construction activities are presented in
Table 10.
Table 10--Calculations for Incidental Take Estimation
----------------------------------------------------------------------------------------------------------------
Animals in Proposed authorized takes
Species ensonified Number of days -------------------------------
area/day of activity Level A Level B
----------------------------------------------------------------------------------------------------------------
Harbor Porpoise................................. 0.90 72 0 65
Gray Seal....................................... 0.21 72 0 15
Harbor Seal..................................... 0.19 72 0 14
Harp Seal....................................... 0.012 72 0 1
---------------------------------------------------------------
Total Exposures............................. .............. .............. .............. 95
----------------------------------------------------------------------------------------------------------------
Analysis and Preliminary Determinations
Negligible Impact
Negligible impact is ``an impact resulting from the specified
activity that cannot be reasonably expected to, and is not reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival'' (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes,
alone, is not enough information on which to base an impact
determination. In addition to considering estimates of the number of
marine mammals that might be ``taken'' through behavioral harassment,
NMFS must consider other factors, such as the likely nature of any
responses (their intensity, duration, etc.), the context of any
responses (critical reproductive time or location, migration, etc.), as
well as the number and nature of estimated Level A harassment takes,
the number of estimated mortalities, effects on habitat, and the status
of the species.
To avoid repetition, the discussion of our analyses applies to all
the species listed in Table 2, given that the anticipated effects of
this pile driving project on marine mammals are expected to be
relatively similar in nature. There is no information about the size,
status, or structure of any species or stock that would lead to a
different analysis for this activity, else species-specific factors
would be identified and analyzed.
Pile driving activities associated with the Navy's Waterfront
Improvement Projects, as outlined previously, have the potential to
disturb or displace marine mammals. Specifically, the specified
activities may result in take, in the form of Level B harassment
(behavioral disturbance) only, from underwater sounds generated from
pile driving. Harassment takes could occur if individuals of these
species are present in the ensonified zone when pile driving is
happening.
No injury, serious injury, or mortality is anticipated given the
nature of the activity and measures designed to minimize the
possibility of injury to marine mammals. The potential for these
outcomes is minimized through the implementation of the following
planned mitigation measures. The Navy will employ a ``soft start'' when
initiating impact driving activities. Given sufficient ``notice''
through use of soft start, marine mammals are expected to move away
from a pile driving source. The Navy will delineate and monitor
shutdown and disturbance zones while the likelihood of marine mammal
detection by trained observers is high under the environmental
conditions described for waters around the project area. Furthermore,
shutdowns will occur if animals come within 10 meters of operational
activity to avoid injury, serious injury, or mortality. The Navy's
proposed activities are localized and of relatively short duration. The
total time duration will amount to approximately 72 days.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat, as analyzed in detail in
the ``Anticipated Effects on Marine Mammal Habitat'' section. No
important feeding and/or reproductive areas for marine mammals are
known to be near the proposed project area. Project-related activities
may cause some fish to leave the area
[[Page 52633]]
of disturbance, thus temporarily impacting marine mammals' foraging
opportunities in a limited portion of the foraging range; but, because
of the short duration of the activities and the relatively small area
of the habitat that may be affected, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences.
These localized Level B exposures may cause brief startle reactions
or short-term behavioral modification by the animals. Effects on
individuals that are taken by Level B harassment, on the basis of
reports in the literature as well as monitoring from other similar
activities, will likely be limited to reactions such as increased
swimming speeds, increased surfacing time, or decreased foraging (if
such activity were occurring) (e.g., Thorson and Reyff, 2006; Lerma,
2014). Most likely, individuals will simply move away from the sound
source and be temporarily displaced from the areas of pile driving,
although even this reaction has been observed primarily only in
association with impact pile driving. These reactions and behavioral
changes are expected to subside quickly when the exposures cease. The
pile driving activities analyzed here are similar to, or less impactful
than, numerous construction activities conducted in other similar
locations, which have taken place with no reported injuries or
mortality to marine mammals, and no known long-term adverse
consequences from behavioral harassment. Repeated exposures of
individuals to levels of sound that may cause Level B harassment here
are unlikely to result in hearing impairment or to significantly
disrupt foraging behavior. Thus, even repeated Level B harassment of
some small subset of the species is unlikely to result in any
significant realized decrease in fitness for the affected individuals,
and thus would not result in any adverse impact to the stock as a
whole. Level B harassment will be reduced to the level of least
practicable impact through use of mitigation measures described herein.
Finally, if sound produced by project activities is sufficiently
disturbing, animals are likely to simply avoid the project area while
the activity is occurring.
In summary, the negligible impact analysis is based on the
following: (1) The possibility of injury, serious injury, or mortality
may reasonably be considered discountable; (2) the anticipated
incidents of Level B harassment consist of, at worst, temporary
modifications in behavior; (3) the absence of any significant habitat
within the project area, including rookeries, significant haul-outs, or
known areas or features of special significance for foraging or
reproduction; and (4) the anticipated efficacy of the proposed
mitigation measures in reducing the effects of the specified activity.
In combination, we believe that these factors, as well as the available
body of evidence from other similar activities, demonstrate that the
potential effects of the specified activity will have only short-term
effects on individuals. The specified activity is not expected to
impact rates of recruitment or survival and will therefore have a
negligible impact on those species.
Therefore, based on the analysis contained herein of the likely
effects of the specified activity on marine mammals and their habitat,
and taking into consideration the implementation of the proposed
monitoring and mitigation measures, NMFS preliminarily finds that the
total marine mammal take from the Navy's proposed Waterfront
Improvement Projects will have a negligible impact on the affected
marine mammal species or stocks.
Small Numbers
Table 11 illustrates the numbers of animals that could be exposed
to Level B behavioral harassment thresholds from work associated with
the proposed Waterfront Improvement Projects. The analyses provided
represents <0.01% of the populations of these stocks that could be
affected by Level B behavioral harassment. These are small numbers of
marine mammals relative to the sizes of the affected species and
population stocks under consideration.
Table 11--Estimated Number of Exposures and Percentage of Stocks That May Be Subject to Level B Harassment
----------------------------------------------------------------------------------------------------------------
Proposed Stock(s) Percentage of
Species authorized abundance total stock
takes estimate (percent)
----------------------------------------------------------------------------------------------------------------
Harbor Porpoise, Gulf of Maine/Bay of Fundy stock............... 65 79,883 <0.01
Gray Seal, Western North Atlantic stock......................... 15 331,000 <0.01
Harbor Seal, Western North Atlantic stock....................... 14 75,834 <0.01
Harp Seal, Western North Atlantic stock......................... 1 7,100,000 <0.01
----------------------------------------------------------------------------------------------------------------
Based on the methods used to estimate take, and taking into
consideration the implementation of the mitigation and monitoring
measures, we preliminarily find that small numbers of marine mammals
will be taken relative to the populations of the affected species or
stocks.
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no relevant subsistence uses of marine mammals implicated
by this action. Therefore, NMFS has determined that the total taking of
affected species or stocks would not have an unmitigable adverse impact
on the availability of such species or stocks for taking for
subsistence purposes.
Endangered Species Act (ESA)
No species listed under the ESA are expected to be affected by
these activities. Therefore, NMFS has determined that a section 7
consultation under the ESA is not required.
National Environmental Policy Act (NEPA)
The Navy has prepared a draft Environmental Assessment (Waterfront
Improvement Projects, Portsmouth Naval Shipyard, Kittery, ME) in
accordance with the National Environmental Policy Act (NEPA) and the
regulations published by the Council on Environmental Quality. NMFS
will independently evaluate the EA and determine whether or not to
adopt it. We may prepare a separate NEPA analysis and incorporate
relevant portions of Navy's EA by reference. Information in the Navy's
application, EA, and this notice collectively provide the environmental
information related to proposed issuance of this IHA for public review
and comment. We will review all comments submitted in response to this
notice as we complete the NEPA process, including a decision of whether
to sign a Finding of No Significant Impact (FONSI), prior to a
[[Page 52634]]
final decision on the incidental take authorization request.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the Navy for Waterfront Improvements Projects at the
Portsmouth Naval Shipyard in Kittery, Maine, provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated. The proposed IHA language is provided next.
1. This Incidental Harassment Authorization (IHA) is valid from
January 1, 2017 through December 31, 2017.
2. This Authorization is valid only for in-water construction work
associated with Waterfront Improvement Projects at the Portsmouth Naval
Shipyard in Kittery, Maine.
3. General Conditions
(a) A copy of this IHA must be in the possession of the Navy, its
designees, and work crew personnel operating under the authority of
this IHA.
(b) The species authorized for taking are harbor porpoise (Phocoena
phocoena), gray seal (Halichoerus grypus), harbor seal (Phoca
vitulina), and harp seal (Pagophilus groenlandicus).
(c) The taking, by Level B harassment only, is limited to the
species listed in condition 3(b). See Table 1 below:
Table 1--Authorized Take Numbers
------------------------------------------------------------------------
Authorized Authorized
Species takes-- takes--
Level A Level B
------------------------------------------------------------------------
Harbor Porpoise................................. 0 65
Gray Seal....................................... 0 15
Harbor Seal..................................... 0 14
Harp Seal....................................... 0 1
------------------------------------------------------------------------
(d) The taking by injury (Level A harassment), serious injury, or
death of any of the species listed in condition 3(b) of the
Authorization or any taking of any other species of marine mammal is
prohibited and may result in the modification, suspension, or
revocation of this IHA.
(e) The Navy shall conduct briefings between construction
supervisors and crews, marine mammal monitoring team, and staff prior
to the start of all in-water pile driving, and when new personnel join
the work, in order to explain responsibilities, communication
procedures, marine mammal monitoring protocol, and operational
procedures.
4. Mitigation Measures
The holder of this Authorization is required to implement the
following mitigation measures:
(a) Time Restriction: For all in-water pile driving activities, the
Navy shall operate only during daylight hours.
(b) Pile Driving Weather Delays: Pile driving shall only take place
when the entire ZOI is visible and can be adequately monitored. If
conditions (e.g., fog) prevent the visual detection of marine mammals,
activities with the potential to result in Level A or Level B
harassment will not be initiated. If such conditions arise after the
activity has begun, impact pile driving would be curtailed, but
vibratory pile driving or extraction would be allowed to continue.
(c) If a marine mammal approaches the shutdown zone during the
course of pile driving/removal operations, pile driving shall be halted
and delayed until either the animal has voluntarily left and been
visually confirmed beyond the shutdown zone or 15 minutes have passed
without re-detection of the animal.
(d) Establishment of Level A and B Harassment (ZOI)
(i) For all pile driving, the Navy shall implement a minimum
shutdown zone of 10 m radius around the pile. If a marine mammal comes
within or approaches the shutdown zone, such operations will cease. See
Table 9 for minimum radial distances required for Level A and Level B
disturbance zones.
(e) Use of Soft-start
(i) The project shall utilize soft start techniques for impact pile
driving. The Navy shall conduct an initial set of three strikes from
the impact hammer at 40 percent energy, followed by a 1-minute waiting
period, then two subsequent three strike sets. Soft start shall be
required for any impact driving, including at the beginning of the day,
and at any time following a cessation of pile driving of thirty minutes
or longer.
(ii) Whenever there has been downtime of 30 minutes or more without
impact driving, the contractor shall initiate the driving with soft-
start procedures described above.
(f) Standard mitigation measures
(i) For in-water heavy machinery work other than pile driving
(using, e.g., standard barges, tug boats), if a marine mammal comes
within 10 m, operations shall cease and vessels shall reduce speed to
the minimum level required to maintain steerage and safe working
conditions.
(g) Visual Marine Mammal Monitoring and Observation
(i) A minimum of two MMOs shall be in place at the best practicable
vantage points.
(ii) Monitoring will be conducted during all impact driving
activity and during two-thirds of all vibratory driving activity
(iii) MMOs shall begin observing for marine mammals within the
Level A and Level B harassment zones for 15 minutes before in-water
pile driving begins. If a marine mammal(s) is present within the 10
meter shutdown zone prior to pile driving or during the ``soft start''
the start of pile driving shall be delayed until the animal(s) leaves
the 10 meter shutdown zone. Pile driving shall resume only after the
MMOs have determined, through sighting or by waiting 15 minutes, that
the animal(s) has moved outside of and is on a path away from the 10
meter shutdown zone.
(iv) The individuals shall scan the waters within each monitoring
zone activity using binoculars (25x or equivalent), hand held
binoculars (7x) and visual observation
(v) The waters shall continue to be scanned for at least 30 minutes
after pile driving has completed each day.
5. Monitoring and Reporting
The holder of this Authorization is required to submit a draft
report on all monitoring conducted under the IHA 60 days prior to the
issuance of a subsequent authorization, A final report shall be
prepared and submitted within thirty days following resolution of
comments on the draft report from NMFS. This report must contain the
informational elements described in the Monitoring Plan, at a minimum
and shall also include:
(a) Acoustic Monitoring
(i) The Navy shall conduct acoustic monitoring to ensure source
levels are in line what is expected and therefore the Level A and Level
B zones are accurate.
(b) Data Collection
(i) For all marine mammal and acoustic monitoring, information
shall be recorded as described in the Monitoring Plan.
(c) Reporting Measures
(i) In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA,
such as an injury (Level A harassment), serious injury or mortality
(e.g., ship-strike, gear interaction, and/or entanglement), the Navy
shall immediately cease the specified activities and the Navy shall
report the incident to the Chief of the Permits and Conservation
Division, Office of Protected Resources, NMFS, and the NMFS Northeast/
Greater Atlantic Regional Stranding Coordinator within 24 hours of the
discovery. The report would include the following information:
1. Time, date, and location (latitude/longitude) of the incident;
[[Page 52635]]
2. Name and type of vessel involved;
3. Vessel's speed during and leading up to the incident, if
applicable;
4. Description of the incident;
5. Status of all sound source use in the 24 hours preceding the
incident;
6. Water depth;
7. Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
8. Description of all marine mammal observations in the 24 hours
preceding the incident;
9. Species identification or description of the animal(s) involved;
10. Fate of the animal(s); and
11. Photographs or video footage of the animal(s) (if equipment is
available).
(ii) Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS shall work with the Navy to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. The Navy would not be able
to resume their activities until notified by NMFS via letter, email, or
telephone.
(iii) In the event that the Navy discovers an injured or dead
marine mammal, and the lead MMO determines that the cause of the injury
or death is unknown and the death is relatively recent (i.e., in less
than a moderate state of decomposition as described in the next
paragraph), the Navy shall report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
and the NMFS Northeast/Greater Atlantic Regional Stranding hotline and/
or by email to the Northeast/Greater Atlantic Regional Stranding
Coordinator within 24 hours of the discovery. The report shall include
the same information identified in the paragraph above. Activities
would be able to continue while NMFS reviews the circumstances of the
incident. NMFS would work with the Navy to determine whether
modifications in the activities are appropriate.
(iv) In the event that the Navy discovers an injured or dead marine
mammal, and the lead MMO determines that the injury or death is not
associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), the Navy shall report the incident
to the Chief of the Permits and Conservation Division, Office of
Protected Resources, NMFS, and the NMFS Northeast/Greater Atlantic
Regional Stranding hotline and/or by email to the Northeast/Greater
Atlantic Regional Stranding Coordinator within 24 hours of the
discovery. The Navy would provide photographs or video footage (if
available) or other documentation of the stranded animal sighting to
NMFS and the Marine Mammal Stranding Network.
6. This Authorization may be modified, suspended or withdrawn if
the holder fails to abide by the conditions prescribed herein, or if
NMFS determines the authorized taking is having more than a negligible
impact on the species or stock of affected marine mammals.
Request for Public Comments
NMFS requests comment on our analysis, the draft authorization, and
any other aspect of the Notice of Proposed IHA for the Navy's
Waterfront Improvement Projects at Portsmouth Navy Shipyard in Kittery,
Maine. Please include with your comments any supporting data or
literature citations to help inform our final decision on the Navy's
request for an MMPA authorization.
Dated: August 3, 2016.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2016-18815 Filed 8-8-16; 8:45 am]
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