[Federal Register Volume 87, Number 153 (Wednesday, August 10, 2022)]
[Notices]
[Pages 48623-48648]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-17141]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC114]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to In-Water Construction at Two Ferry
Facilities on Bainbridge Island, Washington
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization (IHA);
request for comments on proposed authorization and possible renewal.
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SUMMARY: NMFS has received a request from the Washington State
Department of Transportation Ferries Division (WSDOT) for authorization
to take marine mammals incidental to two in-water construction projects
on Bainbridge Island, Washington: the Bainbridge Island Ferry Terminal
Overhead Loading Replacement Project and Eagle Harbor Maintenance
Facility Slip F Improvement Project. Pursuant to the Marine Mammal
Protection Act (MMPA), NMFS is requesting comments on its proposal to
issue an IHA to incidentally take marine mammals during the specified
activities. NMFS is also requesting comments on a possible one-time,
one-year renewal that could be issued under certain circumstances and
if all requirements are met, as described in Request for Public
Comments at the end of this notice. NMFS will consider public comments
prior to making any final decision on the issuance of the requested
MMPA authorization and agency responses will be summarized in the final
notice of our decision.
DATES: Comments and information must be received no later than
September 9, 2022.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service and should be submitted via email 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, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at
[[Page 48624]]
www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act 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: Amy Fowler, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems
accessing these documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) 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 proposed or, if the taking is limited to harassment, a notice of a
proposed incidental harassment authorization is provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has
preliminarily determined that the issuance of the proposed IHA
qualifies to be categorically excluded from further NEPA review.
We will review all comments submitted in response to this notice
prior to concluding our NEPA process or making a final decision on the
IHA request.
Summary of Request
On February 15, 2022, NMFS received a request from WSDOT for an IHA
to take marine mammals incidental to the Bainbridge Island Ferry
Terminal Overhead Loading Replacement Project (the Bainbridge Project)
and Eagle Harbor Maintenance Facility Slip F Improvement Projects (the
Eagle Harbor Project) in Bainbridge Island, Washington. The application
was deemed adequate and complete on July 25, 2022. WSDOT's request is
for take of 12 species of marine mammal by Level B harassment and, for
a subset of these species (harbor seal (Phoca vitulina), harbor
porpoise (Phocoena phocoena), and Dall's porpoise (Phocoenoides
dalli)), Level A harassment. Neither WSDOT nor NMFS expect serious
injury or mortality to result from this activity and, therefore, an IHA
is appropriate.
Description of Proposed Activity
Overview
The Washington State Department of Transportation (WSDOT) Ferries
Division (WSF) operates and maintains 19 ferry terminals and one
maintenance facility, all of which are located in either Puget Sound or
the San Juan Islands. Two projects are proposed to be conducted:
replacement of the Bainbridge Island Ferry Terminal overhead loading
structure, and improvement of the Eagle Harbor Maintenance Facility
Slip F. Both of the projects are located within Eagle Harbor on
Bainbridge Island, Washington, would be completed within the same in-
water work season, would have overlapping ensonified areas, and use the
same datasets to estimate marine mammal takes. Therefore, WSDOT has
submitted one application for a single IHA to cover both projects.
The purpose of the Bainbridge Project is to replace the seismically
vulnerable timber trestle and fixed steel portions of the overhead
loading structure at the Bainbridge Island Ferry Terminal. The purpose
of the Eagle Harbor Project is to improve the maintenance efficiency of
the facility. The facility has six vessel slips whose purpose is to
maintain the Washington State Ferry (WSF) system's vessels.
Dates and Duration
Due to in-water work timing restrictions established by NMFS and
the U.S. Army Corps of Engineers, construction in the projects area is
limited each year from August 1 through February 15. Both the
Bainbridge Project and the Eagle Harbor Project would be constructed
during the August 1, 2022 to February 15, 2023 in-water work season.
For the Bainbridge Project, in-water construction is expected to occur
on up to 57 days (Table 1). For the Eagle Harbor Project, in-water
construction is expected to occur on up to 31 days (Table 2).
Specific Geographic Region
Both projects are located within Eagle Harbor on Bainbridge Island,
Washington, approximately 9 miles (mi; 14.5 kilometers (km)) west of
Seattle, Washington. The Eagle Harbor Maintenance Facility is
approximately \1/4\ mi (0.4 km) southwest of the Bainbridge Island
Ferry Terminal. Eagle Harbor contains a mix of commercial docks, public
marinas, private docks, and undeveloped waterfront properties. The
harbor extends 2 mi (1.2 km) west from the mouth of the harbor, which
is approximately 900 feet (ft; 274.3 meters (m)) wide and is bounded by
Wing Point to the north and Bill Point to the south. A large underwater
sand bar extends to the southeast from Wing Point. Water depths within
Eagle Harbor range are up to 50 ft (15.2 m) but outside the harbor,
water depths between Bainbridge Island and Seattle can be over 700 ft
(213.4 m).
[[Page 48625]]
[GRAPHIC] [TIFF OMITTED] TN10AU22.251
Detailed Description of Specific Activity
Bainbridge Project
The existing overhead loading fixed walkway at the Bainbridge
Island Ferry Terminal consists of two major components: a timber
trestle, constructed in 1972, which is approximately 345 ft (105.2 m)
long and supported on timber batter piles; and a steel truss,
constructed in 1988, which is approximately 78 ft (23.8 m) long and
supported on a concrete shaft at each end. The walkway is elevated
approximately 40 ft (12.2 m) above ground.
The proposed project elements for the Bainbridge Project include:
1. Installation of temporary work platforms: two temporary work
platforms would support construction equipment. A total of 31 24-inch
(in) steel pipe piles would support the structures, which would be
installed first using a vibratory hammer to within 5 ft (1.5 m) of tip
elevation, and then driven with an impact hammer to verify bearing
capacity.
2. Installation of temporary walkway: a temporary walkway would be
constructed to maintain overhead loading operations while the new
walkway is constructed. This would allow the inshore portion of the
existing walkway to be demolished so the new walkway can be
constructed. The offshore portion of the existing walkway would remain
to allow passenger loading until the new walkway is completed. The
temporary walkway would be supported on four 24-inch diameter steel
piles, which would be installed first using a vibratory hammer to
within 5 ft (1.5 m) of tip elevation, and then driven with an impact
hammer to verify bearing capacity.
3. Installation of new permanent walkway: the new walkway would be
supported by 14 30-in and 12 36-in steel pipe piles, which would be
installed first using a vibratory hammer to within 5 ft (1.5 m) of tip
elevation, and then driven with an impact hammer to verify bearing
capacity.
4. Removal of existing overhead loading walkway: the existing
overhead loading walkway, including 76 creosote-treated 12-in timber
piles and one 4.5 ft (1.4 m) diameter concrete drill shaft, would be
removed. The piles would be removed using a vibratory hammer and the
concrete drill shaft would be removed by cutting it with a saw at the
mudline.
5. Removal of temporary walkway and work platform: after the new
walkway is constructed, all piles associated with the temporary walkway
and work platform would be removed with a vibratory hammer.
The construction schedule would be coordinated to allow work to
occur around ferry boats that may be present in the Bainbridge Island
Ferry Terminal slips.
[[Page 48626]]
Table 1--Proposed Pile Driving for the Bainbridge Project
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Duration per
Project element Pile size and Install or remove Method Number of pile Piles per day Duration
type piles (minutes) (days)
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Temporary work platform and 24-in Steel...... Install.......... Vibratory........ 39 30 4 10
temporary walkway.
Impact........... 39 30 4 10
Remove........... Vibratory........ 39 30 4 10
New Overhead Loading Structure. 24-in Steel...... Install.......... Vibratory........ 6 30 2 3
Impact........... 6 30 2 3
30-in Steel...... Install.......... Vibratory........ 4 30 2 2
Impact........... 4 30 2 2
36-in Steel...... Install.......... Vibratory........ 12 30 2 6
Impact........... 12 30 2 6
Old Overhead Loading Structure 12-in Timber..... Remove........... Vibratory........ 76 15 15 5
Removal.
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Total Temporary Piles Installed and Removed............................................. 39 .............. .............. ..............
Total Permanent Piles Installed......................................................... 26 .............. .............. ..............
Total Timber Piles Removed.............................................................. 76 .............. .............. ..............
Total Duration (days)................................................................... .............. .............. .............. 57
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Eagle Harbor Project
The last seven vessels built for the WSF fleet have evacuation
slides on the passenger deck. These require the use of a vehicle drive-
on slip to allow changing out these slides. Currently, only two of the
six slips are vehicle drive-on slips. This results in delays when more
than two vessels are undergoing maintenance. A new vehicle drive-on
slip would be constructed to reduce maintenance delays, and provide
more flexibility in accomplishing the various maintenance activities on
the vessels that is crucial to making the WSF system as reliable as
possible.
The proposed project elements for the Eagle Harbor Project include:
1. Trestle and transfer span: The vehicle transfer span is the link
for vehicles to load and unload from the fixed trestle to the vehicle
deck of the ferry vessel. At Eagle Harbor, the existing Slip F
gangplank system would be replaced with a new pile supported trestle
and a transfer span adjustable with a mechanical system. The new
trestle would be approximately 15-ft (4.6 m) wide and 80 ft (24.4 m)
long, and will be supported by nine 24-in steel pipe piles and two 36-
in steel pipe piles which would each be installed first using a
vibratory hammer to within 5 ft (1.5 m) of tip elevation, and then
driven with an impact hammer to verify bearing capacity.
2. Wingwalls and dolphins: The existing pair of timber dolphins
would be replaced with a new pair of steel wingwalls. Two new fixed
pile dolphins would be constructed adjacent to the Trask Pier. The
wingwalls design would consist of four 36-inch diameter steel reaction
piles and two 36-inch diameter fender piles. Two fixed dolphins would
be constructed adjacent to the Trask Pier to provide protection to the
pier and mooring lines for tie-up. The dolphin design would consist of
four 30-inch diameter steel reaction piles and one 36-inch diameter
fender pile. Wingwall and dolphin piles would be installed using a
vibratory hammer only.
3. Removal of timber walkway, timber dolphins, and U-float: the
project would also include the removal of a currently existing timber
walkway/trestle, four timber pile dolphins, and a U-float. The timber
trestle removal includes 52 12-inch diameter timber piles, the four
dolphins include a total of 134 12-inch diameter timber piles, and the
U-float consists of four 18-inch diameter steel piles, all of which
would be removed using a vibratory hammer.
Table 2--Proposed Pile Driving for the Eagle Harbor Project
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Number of Duration per Duration Duration
Project element Pile size and type Install or remove Method piles pile (minutes) (hours) Rate per day (days)
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Timber Walkway Pile Removal.......... 12-in Timber........... Remove................. Vibratory.............. 52 15 13 15 4
Timber Dolphin Removal............... 12-in Timber........... Remove................. Vibratory.............. 134 15 33.5 15 9
Temporary Relocated Float............ 18-in Steel............ Install................ Vibratory.............. 4 30 4 4 1
Remove................. 4 30 3 4 1
U-Float Removal...................... 18-in Steel............ Remove................. Vibratory.............. 4 30 4 4 1
Trestle and Transfer Span............ 24-in Steel............ Install................ Vibratory.............. 9 30 4.5 4 3
Impact................. 9 30 4.5 3 3
36-inSteel............. Install................ Vibratory.............. 2 30 1 4 1
Impact................. 2 30 1 3 1
Wingwall............................. 30-in Steel............ Install................ Vibratory.............. 8 30 4 4 2
36-in Steel............ Install................ Vibratory.............. 4 30 2 4 1
[[Page 48627]]
Intermediate Dolphin................. 30-in Steel............ Install................ Vibratory.............. 4 30 2 4 1
36-in Steel............ Install................ Vibratory.............. 1 30 5 4 1
Outer Dolphin........................ 30-in Steel............ Install................ Vibratory.............. 4 30 2 4 1
36-in Steel............ Install................ Vibratory.............. 2 30 1 4 1
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Total Piles Removed............................................................................................. 194
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Total Piles Installed........................................................................................... 38
Total Duration (days)........................................................................................... .............. .............. .............. .............. 31
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Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, incorporated here by reference, instead of
reprinting the information. Additional information regarding population
trends and threats may be found in NMFS' Stock Assessment Reports
(SARs; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these
species (e.g., physical and behavioral descriptions) may be found on
NMFS' website (https://www.fisheries.noaa.gov/find-species).
Table 3 lists all species or stocks for which take is expected and
proposed to be authorized for this activity, and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no serious injury or mortality is anticipated or
authorized here, PBR and annual serious injury and mortality from
anthropogenic sources are included here as gross indicators of the
status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Pacific and Alaska SARs. All values presented in Table 3 are
the most recent available at the time of publication and are available
in the 2020 SARs (Carretta et al., 2021, Muto et al., 2021) and draft
2021 SARs (available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).
Table 3--Species Likely Impacted by the Specified Activities
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Stock abundance
ESA/MMPA status; strategic (CV, Nmin, most Annual M/
Common name Scientific name Stock (Y/N) \1\ recent abundance PBR SI \3\
survey) \2\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
Gray whale.................... Eschrichtius Eastern N Pacific... -, -, N 26,960 (0.05, 801 131
robustus. 25,849, 2016).
Family Balaenopteridae (rorquals):
Minke whale................... Balaenoptera California/Oregon/ -, -, N 915 (0.792, 509, 4.1 >=0.59
acutorostrata. Washington. 2018).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Long-Beaked Common Dolphin.... Delphinus capensis.. California.......... -, -, N 83,379 (0.216, 668 >=29.7
69,636, 2018).
Bottlenose Dolphin............ Tursiops truncatus.. California Coastal.. -, -, N 453 (0.06, 346, 2.7 >=2.0
2011).
Pacific White-Sided Dolphin... Lagenorhynchus California/Oregon/ -, -, N 34,999 (0.222, 279 7
obliquidens. Washington. 29,090, 2018).
Killer Whale.................. Orcinus orca........ West Coast Transient -, -, N 349 \4\ (N/A, 349, 3.5 0.4
2018).
Family Phocoenidae (porpoises):
Harbor Porpoise............... Phocoena phocoena... Washington Inland -, -, N 11,233 (0.37, 8,308, 66 >=7.2
Waters. 2015).
Dall's Porpoise............... Phocoenoides dalli.. California/Oregon/ -, -, N 16,498 (0.61, 99 >=0.66
Washington. 10,286, 2019).
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[[Page 48628]]
Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California Sea Lion........... Zalophus U.S................. -, -, N 257,606 (N/A, 14,011 >320
californianus. 233,515, 2014).
Steller Sea Lion.............. Eumetopias jubatus.. Eastern............. -, -, N 43,201 \5\ (see SAR, 2,592 112
43,201, 2017).
Family Phocidae (earless seals):
Harbor Seal................... Phoca vitulina...... Washington Northern -, -, N 11,036 \6\ (UNK, UND 9.8
Inland Waters. UNK, 1999).
Northern Elephant Seal........ Mirounga California Breeding. -, -, N 187,386 (N/A, 5,122 13.7
angustirostris. 85,369, 2013).
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\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual mortality/serious injury (M/SI) often cannot be determined precisely and is in some cases presented as a
minimum value or range.
\4\ Based on counts of individual animals identified from photo-identification catalogues. Surveys for abundance estimates of these stocks are conducted
infrequently.
\5\ Best estimate of pup and non-pup counts, which have not been corrected to account for animals at sea during abundance surveys.
\6\ The abundance estimate for this stock is greater than eight years old and is therefore not considered current. PBR is considered undetermined for
this stock, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as
these represent the best available information for use in this document.
As indicated above, all 12 species (with 12 managed stocks) in
Table 3 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. While humpback whales
(Megaptera novaeangliae) and killer whales from the Southern Resident
stock are known to occur in Puget Sound, in consideration of the
proposed requirements described in the Proposed Mitigation and Proposed
Monitoring and Reporting sections of this notice, WSDOT has determined
that take of these species is unlikely to occur and has therefore not
requested take of humpback whales or Southern Resident killer whales.
NMFS has concurred with this determination and no take of these species
is anticipated or proposed to be authorized.
Gray Whale
Gray whales generally spend the summer and fall in Arctic feeding
grounds and winter to early spring in Mexican breeding areas. Between
October and February, the species migrates south along the U.S. West
Coast, returning north between February and July (Carretta et al.,
2021). A subpopulation of the Eastern North Pacific stock, referred to
as the Pacific Coast Feeding Group (PCFG), remains along the Washington
and Oregon coast to feed for extended periods while the rest of the
stock continues along their migratory path (Calambokidis et al., 2018).
Occurrence of gray whales in Puget Sound has been steadily increasing
in recent years and is generally highest between February and May. Most
gray whales remain further north in Puget Sound, concentrating in the
waters around Whidbey Island, but some venture south, including into
Elliott Bay near WSDOT's proposed activities (Orca Network, 2021).
During 372 total days of construction at the Washington State Ferries
Multimodal Project at Colman Dock in Seattle between 2017 and 2021, a
total of 4 gray whales were observed, with a maximum of 1 individual
observed on a single day.
Biologically Important Areas (BIAs) for feeding gray whales along
the coasts of Washington, Oregon, and California have been identified,
including northern Puget Sound, Northwestern Washington, and Grays
Harbor in Washington, Depoe Bay and Cape Blanco and Orford Reef in
Oregon, and Point St. George in California; most of these areas are of
importance from late spring through early fall (Calambokidis et al.,
2015). BIAs have also been identified for migrating gray whales along
the entire coasts of Washington (including the inland waters of Puget
Sound), Oregon, and California; although most whales travel within 10
km from shore, the BIAs were extended out to 47 km from the coastline
(Calambokidis et al., 2015).
On May 30, 2019, NMFS declared an unusual mortality event (UME) for
gray whales after elevated numbers of strandings occurred along the
U.S. west coast. As of January 7, 2022, a total of 502 stranded gray
whales have been reported, including 256 in the United States (117 in
Alaska, 56 in Washington, 12 in Oregon, and 71 in California), 225 in
Mexico, and 21 in Canada. Full or partial necropsy examinations were
conducted on a subset of the whales. Preliminary findings in several of
the whales have shown evidence of emaciation. These findings are not
consistent across all of the whales examined, so more research is
needed. The UME is ongoing, and NMFS continues to investigate the
cause(s). Additional information about the UME is available at https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2020-gray-whale-unusual-mortality-event-along-west-coast.
Minke Whale
The International Whaling Commission (IWC) recognizes three stocks
of minke whales in the North Pacific: The Sea of Japan/East China Sea,
the rest of the western Pacific west of 180[deg] N, and the remainder
of the Pacific (Donovan 1991). Minke whales are relatively common in
the Bering and Chukchi seas and in the Gulf of Alaska, but are not
considered abundant in any other part of the eastern Pacific
(Brueggeman et al., 1990). In the far north, minke whales are thought
to be migratory, but they are believed to be year-round residents in
coastal waters off the west coast of the United States (Dorsey et al.,
1990).
Minke whales are reported in Washington inland waters year-round,
although few are reported in the winter (i.e., during the anticipated
in-water work window for these projects;
[[Page 48629]]
Calambokidis and Baird 1994). They are relatively common in the San
Juan Islands and Strait of Juan de Fuca (especially around several of
the banks in both the central and eastern Strait), but are relatively
rare in Puget Sound and the Orca Network has no sighting records of
minke whales in the project areas. During 372 total days of
construction at the Washington State Ferries Multimodal Project at
Colman Dock in Seattle between 2017 and 2021, a single minke whale was
observed.
Long-Beaked Common Dolphin
Long-beaked common dolphins are commonly found along the U.S. West
Coast, from Baja California, Mexico (including the Gulf of California),
northward to about central California (Carretta et al., 2020). The
Salish Sea is not considered part of their typical range (Carretta et
al., 2020), but there have been reports of long-beaked common dolphins
in inland waters. Two individual common dolphins were observed in
August and September of 2011 (Whale Museum, 2015). The first record of
a pod of long-beaked common dolphins in this area came in the summer of
2016. Beginning on June 16, 2016 long-beaked common dolphins were
observed near Victoria, B.C. Over the following weeks, a pod of 15 to
20 (including a calf) was observed in central and southern Puget Sound.
They were positively identified as long-beaked common dolphins (Orca
Network 2016). Two long-beaked common dolphins were observed by
Washington State Department of Transportation (WSDOT) marine mammal
monitors during construction at Washington State Ferries Multimodal
Project at Colman Dock in Seattle during the 2017-18 construction
window (WSDOT 2019).
Bottlenose Dolphin
Bottlenose dolphins are distributed worldwide from approximately
45[deg] N to 45[deg] S. Bottlenose dolphins inhabiting west coast U.S.
waters are considered to be in either the California coastal stock,
which ranges from Mexico to the San Francisco area within approximately
1 kilometer of shore, or the California/Oregon/Washington offshore
stock, which is most commonly found along the California coast,
northward to about the Oregon border. NMFS offshore surveys from 1991
to 2014 resulted in no sightings during study transects off the Oregon
or Washington coasts (Carretta et al., 2019). In September 2017,
however, multiple sightings of a bottlenose dolphin throughout the
Puget Sound and in Elliott Bay were reported to Cascadia Research
Collective and Orca Network. One of the individuals was identified as
belonging to the California coastal stock (Cascadia Research
Collective, 2017). Bottlenose dolphins are considered rare in Puget
Sound but occasional sightings have continued since the initial reports
in 2017 (Orca Network, 2021). During 372 total days of construction at
the Washington State Ferries Multimodal Project at Colman Dock in
Seattle between 2017 and 2021, a total of 6 bottlenose dolphins were
observed, with a maximum of 2 individuals observed on a single day.
Pacific White-Sided Dolphin
The Pacific white-sided dolphin is found in cool temperate waters
of the North Pacific from the southern Gulf of California to Alaska.
Across the North Pacific, it appears to have a relatively narrow
distribution between 38[deg] N and 47[deg] N (Brownell et al., 1999).
In the eastern North Pacific Ocean, the Pacific white-sided dolphin is
one of the most common cetacean species, occurring primarily in shelf
and slope waters (Green et al., 1993; Barlow 2003, 2010). It is known
to occur close to shore in certain regions, including (seasonally)
southern California (Brownell et al., 1999). Results of aerial and
shipboard surveys strongly suggest seasonal north-south movements of
the species between California and Oregon/Washington; the movements
apparently are related to oceanographic influences, particularly water
temperature (Green et al., 1993; Forney and Barlow 1998; Buchanan et
al., 2001). During winter, this species is most abundant in California
slope and offshore areas; as northern waters begin to warm in the
spring, it appears to move north to slope and offshore waters off
Oregon/Washington (Green et al., 1992, 1993; Forney 1994; Forney et
al., 1995; Buchanan et al., 2001; Barlow 2003). The highest encounter
rates off Oregon and Washington have been reported during March-May in
slope and offshore waters (Green et al., 1992). Large groups of Pacific
white-sided dolphins have been observed in San Juan Channel (Orca
Network 2012), north of Puget Sound, and may rarely occur in Central
Puget Sound. During 372 total days of construction at the Washington
State Ferries Multimodal Project at Colman Dock in Seattle between 2017
and 2021, a total of 2 Pacific white-sided dolphins were observed on
one day of construction.
Killer Whale
There are three distinct ecotypes, or forms, of killer whales
recognized in the north Pacific: resident, transient, and offshore. The
three ecotypes differ morphologically, ecologically, behaviorally, and
genetically. Resident killer whales exclusively prey upon fish, with a
clear preference for salmon (Ford and Ellis 2006; Hanson et al., 2010;
Ford et al., 2016), while transient killer whales exclusively prey upon
marine mammals (Caretta et al., 2019). Less is known about offshore
killer whales, but they are believed to consume primarily fish,
including several species of shark (Dahlheim et al., 2008). Currently,
there are eight killer whale stocks recognized in the U.S. Pacific
(Carretta et al., 2021; Muto et al., 2021). Of those, individuals from
the West Coast Transient stock may occur in the project areas and be
taken incidental to WSDOT's proposed activities.
Within Puget Sound, transient killer whales primarily hunt
pinnipeds and porpoises, though some groups will occasionally target
larger whales. The West Coast Transient stock of killer whales occurs
from California through southeast Alaska (Muto et al., 2021). The
seasonal movements of transients are largely unpredictable, although
there is a tendency to investigate harbor seal haulouts off Vancouver
Island more frequently during the pupping season in August and
September (Baird 1994; Ford 2014). Transient killer whales have been
observed in central Puget Sound in all months (Orca Network 2021).
During 372 total days of construction at the Washington State Ferries
Multimodal Project at Colman Dock in Seattle between 2017 and 2021, a
total of 47 transient killer whales were observed, with a maximum of 20
individuals observed on a single day.
Harbor Porpoise
In the eastern North Pacific Ocean, harbor porpoise are found in
coastal and inland waters from Point Barrow, along the Alaskan coast,
and down the west coast of North America to Point Conception,
California (Gaskin 1984). Harbor porpoise are known to occur year-round
in the inland trans-boundary waters of Washington and British Columbia,
Canada (Osborne et al., 1988), and along the Oregon/Washington coast
(Barlow 1988, Barlow et al., 1988, Green et al., 1992). There was a
significant decline in harbor porpoise sightings within southern Puget
Sound between the 1940s and 1990s but sightings have increased
seasonally in the last 10 years (Carretta et al., 2019). Annual winter
aerial surveys conducted by the Washington Department of Fish and
Wildlife from 1995 to 2015 revealed an increasing trend in harbor
porpoise in Washington
[[Page 48630]]
inland waters, including the return of harbor porpoise to Puget Sound.
The data suggest that harbor porpoise were already present in Juan de
Fuca, Georgia Straits, and the San Juan Islands from the mid-1990s to
mid-2000s, and then expanded into Puget Sound and Hood Canal from the
mid-2000s to 2015, areas they had used historically but abandoned.
Changes in fishery-related entanglement was suspected as the cause of
their previous decline and more recent recovery, including a return to
Puget Sound (Evenson et al., 2016). Seasonal surveys conducted in
spring, summer, and fall 2013-2015 in Puget Sound and Hood Canal
documented substantial numbers of harbor porpoise in Puget Sound.
Observed porpoise numbers were twice as high in spring as in fall or
summer, indicating a seasonal shift in distribution of harbor porpoise
(Smultea 2015). The reasons for the seasonal shift and for the increase
in sightings is unknown. During 372 total days of construction at the
Washington State Ferries Multimodal Project at Colman Dock in Seattle
between 2017 and 2021, a total of 413 harbor porpoises were observed,
with a maximum of 40 individuals observed on a single day.
Dall's Porpoise
Dall's porpoises are endemic to temperate waters of the North
Pacific Ocean. Off the U.S. West Coast, they are commonly seen in
shelf, slope, and offshore waters (Morejohn 1979). Sighting patterns
from aerial and shipboard surveys conducted in California, Oregon, and
Washington (Green et al., 1992, 1993; Forney and Barlow 1998; Barlow
2016) suggest that north-south movement between these states occurs as
oceanographic conditions change, both on seasonal and inter-annual time
scales. Dall's porpoise are considered rare in Puget Sound. During 372
total days of construction at the Washington State Ferries Multimodal
Project at Colman Dock in Seattle between 2017 and 2021, a total of 8
Dall's porpoises were observed, with a maximum of 5 individuals
observed on a single day.
California Sea Lion
The California sea lion is the most frequently sighted pinniped
found in Washington waters and uses haul-out sites along the outer
coast, Strait of Juan de Fuca, and in Puget Sound. Haul-out sites are
located on jetties, offshore rocks and islands, log booms, marina
docks, and navigation buoys. This species also may be frequently seen
resting in the water, rafted together in groups in Puget Sound. Only
male California sea lions migrate into Pacific Northwest waters, with
females remaining in waters near their breeding rookeries off the coast
of California and Mexico. The California sea lion was considered rare
in Washington waters prior to the 1950s. More recently, peak numbers of
3,000 to 5,000 animals move into the Salish Sea during the fall and
remain until late spring, when most return to breeding rookeries in
California and Mexico (Jeffries et al., 2000).
California sea lions are often observed in the area of potential
effects and are known to be comfortable and seemingly curious around
human activities. The nearest documented California sea lion haulout is
2.3 mi (3.7 km) southeast of the project sites on Blakely Rocks.
Jeffries et al. (2000) estimated less than 100 California sea lions
occupy the Blakely Rocks haulout site. California sea lions are not
commonly observed in Eagle Harbor but are regularly observed in Elliott
Bay, especially around two navigational buoys near Alki Point, at the
southwest edge of Elliott Bay. During 372 total days of construction at
the Washington State Ferries Multimodal Project at Colman Dock in
Seattle between 2017 and 2021, a maximum of 38 California sea lions
were observed on a single day.
Steller Sea Lion
Steller sea lions range along the North Pacific Rim from northern
Japan to California (Loughlin et al., 1984). There are two separate
stocks of Steller sea lions, the Eastern U.S. stock, which occurs east
of Cape Suckling, Alaska (144[deg] W), and the Western U.S. stock,
which occurs west of that point. Only the Western stock of Steller sea
lions, which is designated as the Western DPS of Steller sea lions, is
listed as endangered under the ESA (78 FR 66139; November 4, 2013).
Unlike the Western U.S. stock of Steller sea lions, there has been a
sustained and robust increase in abundance of the Eastern U.S. stock
throughout its breeding range. The eastern stock of Steller sea lions
has historically bred on rookeries located in Southeast Alaska, British
Columbia, Oregon, and California. However, within the last several
years a new rookery has become established on the outer Washington
coast (at the Carroll Island and Sea Lion Rock complex), with more than
100 pups born there in 2015 (Muto et al., 2020).
Steller sea lions use haul-out locations in Puget Sound, and may
occur at the same haul-outs as California sea lions, but are considered
rare visitors to the waters around Bainbridge Island. Few Steller sea
lions have been observed during monitoring of recent construction
projects in the Seattle area; typically fewer than 5 total observations
per year (e.g., Anchor QEA 2018, 2019). During 372 total days of
construction at the Washington State Ferries Multimodal Project at
Colman Dock in Seattle between 2017 and 2021, a total of 100 Steller
sea lions were observed, with a maximum of 10 Steller sea lions
observed on a single day.
Harbor Seal
Harbor seals inhabit coastal and estuarine waters off Baja
California, north along the western coasts of the continental U.S.,
British Columbia, and Southeast Alaska, west through the Gulf of Alaska
and Aleutian Islands, and in the Bering Sea north to Cape Newenham and
the Pribilof Islands (Carretta et al., 2014). They haul out on rocks,
reefs, beaches, and drifting glacial ice and feed in marine, estuarine,
and occasionally fresh waters. Harbor seals generally are non-
migratory, with local movements associated with such factors as tides,
weather, season, food availability, and reproduction (Scheffer and
Slipp 1944; Fisher 1952; Bigg 1969, 1981). Within U.S. west coast
waters, five stocks of harbor seals are recognized: (1) Southern Puget
Sound (south of the Tacoma Narrows Bridge); (2) Washington Northern
Inland Waters (including Puget Sound north of the Tacoma Narrows
Bridge, the San Juan Islands, and the Strait of Juan de Fuca); (3) Hood
Canal; (4) Oregon/Washington Coast; and (5) California. Harbor seals in
the project areas would be from the Washington Northern Inland Waters
stock.
Harbor seals are the only pinniped species that occurs year-round
and breeds in Washington waters (Jeffries et al., 2000). Pupping
seasons vary by geographic region, with pups born in coastal estuaries
(Columbia River, Willapa Bay, and Grays Harbor) from mid-April through
June; Olympic Peninsula coast from May through July; San Juan Islands
and eastern bays of Puget Sound from June through August; southern
Puget Sound from mid-July through September; and Hood Canal from August
through January (Jeffries et al., 2000). The most recent estimate for
the Washington Northern Inland Waters Stock is 11,036 based on surveys
conducted in 1999. There are no current estimates of abundance for this
stock but the population is thought to be stable (Carretta et al.,
2014).
There is one documented harbor seal haulout area near Bainbridge
Island at Blakely Rocks, approximately 2.3 mi (3.7 km) southeast of the
project sites. The haulout, which is estimated at less
[[Page 48631]]
than 100 animals, consists of intertidal rocks and reef areas
(Jefferies et al., 2000). Harbor seals are a commonly observed marine
mammal in the area of potential effects and are known to be comfortable
and seemingly curious around human activities. Observations of harbor
seals were reported during many recent construction projects along the
Seattle waterfront. During 372 total days of construction at the
Washington State Ferries Multimodal Project at Colman Dock in Seattle
between 2017 and 2021, a maximum of 43 harbor seals were observed on a
single day.
Northern Elephant Seal
Northern elephant seals breed and give birth in California (U.S.)
and Baja California (Mexico), primarily on offshore islands (Stewart et
al., 1994), from December to March (NOAA 2015). Males migrate to the
Gulf of Alaska and western Aleutian Islands along the continental shelf
to feed on benthic prey, while females migrate to pelagic areas in the
Gulf of Alaska and the central North Pacific Ocean to feed on pelagic
prey (Le Boeuf et al., 2000). Adults return to land between March and
August to molt, with males returning later than females. Adults return
to their feeding areas again between their spring/summer molting and
their winter breeding seasons (Carretta et al., 2015).
During 372 total days of construction at the Washington State
Ferries Multimodal Project at Colman Dock in Seattle between 2017 and
2021, a single northern elephant seal was observed. Elephant seals are
generally considered rare in Puget Sound. However, a female elephant
seal has been reported hauled-out in Mutiny Bay on Whidbey Island
periodically since 2010. She was observed alone for her first three
visits to the area, but in March 2015, she was seen with a pup. Since
then, she has produced two more pups, born in 2018 and 2020. Northern
elephant seals generally give birth in January but this individual has
repeatedly given birth in March. She typically returns to Mutiny Bay in
April and May to molt. Her pups have also repeatedly returned to haul-
out on nearby beaches (Orca Network 2020).
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Note that no direct measurements of
hearing ability have been successfully completed for mysticetes (i.e.,
low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 4.
Table 4--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
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
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a discussion of the ways that components of
the specified activity may impact marine mammals and their habitat. The
Estimated Take section later in this document includes a quantitative
analysis of the number of individuals that are expected to be taken by
this activity. The Negligible Impact Analysis and Determination section
considers the content of this section, the Estimated Take section, and
the Proposed Mitigation section, to draw conclusions regarding the
likely impacts of these activities on the reproductive success or
survivorship of individuals and whether those impacts are reasonably
expected to, or reasonably likely to, adversely affect the species or
stock through effects on annual rates of recruitment or survival.
Acoustic effects on marine mammals during the specified activities
can occur from impact pile driving and vibratory driving and removal.
The effects of underwater noise from WSDOT's proposed activities have
the potential to result in Level A or Level B harassment of marine
mammals in the action areas.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far (ANSI 1995). The sound level of an area is
defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., waves, wind,
precipitation, earthquakes, ice, atmospheric sound), biological (e.g.,
[[Page 48632]]
sounds produced by marine mammals, fish, and invertebrates), and
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
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
decibels (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 activities may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In-water construction activities associated with the projects would
include impact and vibratory pile driving and removal. The sounds
produced by these activities fall into one of two general sound types:
impulsive and non-impulsive. Impulsive sounds (e.g., explosions, sonic
booms, impact pile driving) are typically transient, brief (less than 1
second), broadband, and consist of high peak sound pressure with rapid
rise time and rapid decay (ANSI, 1986; NIOSH, 1998; NMFS, 2018). Non-
impulsive sounds (e.g., machinery operations such as drilling or
dredging, vibratory pile driving, underwater chainsaws, and active
sonar systems) can be broadband, narrowband or tonal, brief or
prolonged (continuous or intermittent), and typically do not have the
high peak sound pressure with raid rise/decay time that impulsive
sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). 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).
Two types of hammers would be used on these projects, impact and
vibratory. Impact hammers operate by repeatedly dropping and/or pushing
a heavy piston onto a pile to drive the pile into the substrate. Sound
generated by impact hammers is considered impulsive. Vibratory hammers
install piles by vibrating them and allowing the weight of the hammer
to push them into the sediment. Vibratory hammers produce non-
impulsive, continuous sounds. Vibratory hammering generally produces
SPLs 10 to 20 dB lower than 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).
The likely or possible impacts of WSDOT's proposed activities on
marine mammals could be generated from both non-acoustic and acoustic
stressors. Potential non-acoustic stressors include the physical
presence of the equipment, vessels, and personnel; however, we expect
that any animals that approach the project site(s) close enough to be
harassed due to the presence of equipment or personnel would be within
the Level B harassment zones from pile driving and would already be
subject to harassment from the in-water activities. Therefore, any
impacts to marine mammals are expected to primarily be acoustic in
nature. Acoustic stressors are generated by heavy equipment operation
during pile installation and removal (i.e., impact and vibratory pile
driving and removal).
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving equipment is the primary means by which
marine mammals may be harassed from WSDOT's specified activities. In
general, animals exposed to natural or anthropogenic sound may
experience physical and psychological effects, ranging in magnitude
from none to severe (Southall et al., 2007). Generally, exposure to
pile driving and removal and other construction noise has the potential
to result in auditory threshold shifts and behavioral reactions (e.g.,
avoidance, temporary cessation of foraging and vocalizing, changes in
dive behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses such as an increase in stress
hormones. Additional noise in a marine mammal's habitat can mask
acoustic cues used by marine mammals to carry out daily functions such
as communication and predator and prey detection. The effects of pile
driving and demolition noise on marine mammals are dependent on several
factors, including, but not limited to, sound type (e.g., impulsive vs.
non-impulsive), the species, age and sex class (e.g., adult male vs.
mother with calf), duration of exposure, the distance between the pile
and the animal, received levels, behavior at time of exposure, and
previous history with exposure (Wartzok et al., 2004; Southall et al.,
2007). Here we discuss physical auditory effects (threshold shifts)
followed by behavioral effects and potential impacts on habitat. No
physiological effects other than PTS are anticipated or proposed to be
authorized, and therefore are not discussed further.
NMFS defines a noise-induced threshold shift (TS) as a change,
usually an increase, in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS, 2018). The amount of
threshold shift is customarily expressed in dB. A TS can be permanent
or temporary. As described in NMFS (2018), there are numerous factors
to consider when examining the consequence of TS, including, but not
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough
duration or to a high enough level to induce a TS, the magnitude of the
TS, time to recovery (seconds to minutes or hours to days), the
frequency range of the exposure (i.e., spectral content), the hearing
and vocalization frequency range of the exposed species relative to the
signal's frequency spectrum (i.e., how animal uses sound within the
frequency band of the signal; e.g., Kastelein et al., 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB threshold
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward, 1960;
Kryter et al., 1966; Miller, 1974; Ahroon et al., 1996; Henderson et
al., 2008). PTS levels for marine mammals are estimates, because there
are limited empirical data measuring PTS in marine mammals (e.g.,
Kastak et al., 2008), largely due to the fact that, for various ethical
reasons, experiments involving anthropogenic noise exposure at levels
inducing PTS are not typically pursued or authorized (NMFS, 2018).
Temporary Threshold Shift (TTS)--TTS is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a
[[Page 48633]]
previously established reference level (NMFS, 2018). Based on data from
cetacean TTS measurements (see Southall et al., 2007), a TTS of 6 dB is
considered the minimum threshold shift clearly larger than any day-to-
day or session-to-session variation in a subject's normal hearing
ability (Schlundt et al., 2000; Finneran et al., 2000, 2002). As
described in Finneran (2016), marine mammal studies have shown the
amount of TTS increases with cumulative sound exposure level
(SELcum) in an accelerating fashion: At low exposures with
lower SELcum, the amount of TTS is typically small and the
growth curves have shallow slopes. At exposures with higher
SELcum, the growth curves become steeper and approach linear
relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis))
and five species of pinnipeds exposed to a limited number of sound
sources (i.e., mostly tones and octave-band noise) in laboratory
settings (Finneran, 2015). TTS was not observed in trained spotted
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive
noise at levels matching previous predictions of TTS onset (Reichmuth
et al., 2016). In general, harbor seals and harbor porpoises have a
lower TTS onset than other measured pinniped or cetacean species
(Finneran, 2015). The potential for TTS from impact pile driving
exists. After exposure to playbacks of impact pile driving sounds (rate
2,760 strikes/hour) in captivity, mean TTS increased from 0 dB after 15
minute exposure to 5 dB after 360 minute exposure; recovery occurred
within 60 minutes (Kastelein et al., 2016). Additionally, the existing
marine mammal TTS data come from a limited number of individuals within
these species. No data are available on noise-induced hearing loss for
mysticetes. Nonetheless, what we considered is the best available
science. For summaries of data on TTS in marine mammals or for further
discussion of TTS onset thresholds, please see Southall et al. (2007),
Finneran and Jenkins (2012), Finneran (2015), and Table 5 in NMFS
(2018).
WSDOT proposes to use impact pile driving to install some piles for
these projects. There would likely be pauses in activities producing
the sound (e.g., impact pile driving) during each day. Given these
pauses and the fact that many marine mammals are likely moving through
the project areas and not remaining for extended periods of time, the
potential for TS declines.
Behavioral Harassment--Exposure to noise from pile driving and
removal also has the potential to behaviorally disturb marine mammals.
Available studies show wide variation in response to underwater sound;
therefore, it is difficult to predict specifically how any given sound
in a particular instance might affect marine mammals perceiving the
signal. If a marine mammal does react briefly to an underwater sound by
changing its behavior or moving a small distance, the impacts of the
change are unlikely to be significant to the individual, let alone the
stock or population. However, if a sound source displaces marine
mammals from an important feeding or breeding area for a prolonged
period, impacts on individuals and populations could be significant
(e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 2005).
Disturbance may result in 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); or avoidance of areas where sound sources are located.
Pinnipeds may increase their haul-out time, possibly to avoid in-water
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound
are highly variable and context-specific and any reactions depend on
numerous intrinsic and extrinsic factors (e.g., species, state of
maturity, experience, current activity, reproductive state, auditory
sensitivity, time of day), as well as the interplay between factors
(e.g., Richardson et al., 1995; Wartzok et al., 2004; Southall et al.,
2007; Weilgart, 2007; Archer et al., 2010). Behavioral reactions can
vary not only among individuals but also within an individual,
depending on previous experience with a sound source, context, and
numerous other factors (Ellison et al., 2012), and can vary depending
on characteristics associated with the sound source (e.g., whether it
is moving or stationary, number of sources, distance from the source).
In general, pinnipeds seem more tolerant of, or at least habituate more
quickly to, potentially disturbing underwater sound than do cetaceans,
and generally seem to be less responsive to exposure to industrial
sound than most cetaceans. Please see Appendices B and C of Southall et
al. (2007) for a review of studies involving marine mammal behavioral
responses to sound.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
In 2016, the Alaska Department of Transportation and Public
Facilities (ADOT&PF) documented observations of marine mammals during
construction activities (i.e., pile driving) at the Kodiak Ferry Dock
(see 80 FR 60636, October 7, 2015). In the marine mammal monitoring
report for that project (ABR 2016), 1,281 Steller sea lions were
observed within the Level B disturbance zone during pile driving or
drilling (i.e., documented as Level B harassment take). Of these, 19
individuals demonstrated an alert behavior, 7 were fleeing, and 19 swam
away from the
[[Page 48634]]
project site. All other animals (98 percent) were engaged in activities
such as milling, foraging, or fighting and did not change their
behavior. In addition, two sea lions approached within 20 m of active
vibratory pile driving activities. Three harbor seals were observed
within the disturbance zone during pile driving activities; none of
them displayed disturbance behaviors. Fifteen killer whales and three
harbor porpoise were also observed within the Level B harassment zone
during pile driving. The killer whales were travelling or milling while
all harbor porpoises were travelling. No signs of disturbance were
noted for either of these species. Given the similarities in species,
activities, and habitat (e.g., cool-temperate waters, industrialized
area), we expect similar behavioral responses from the same and similar
species affected by WSDOT's specified activities. That is, disturbance,
if any, is likely to be temporary and localized (e.g., small area
movements).
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg
2000). In many cases, an animal's first and sometimes most economical
(in terms of energetic costs) response is behavioral avoidance of the
potential stressor. Autonomic nervous system responses to stress
typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker 2000; Romano
et al., 2002b) and, more rarely, studied in wild populations (e.g.,
Romano et al., 2002a). For example, Rolland et al. (2012) found that
noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003), however
distress is an unlikely result of these projects based on observations
of marine mammals during previous, similar projects in the area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked. The
Puget Sound area contains active commercial shipping, ferry operations,
and commercial fishing as well as numerous recreational and other
commercial vessels, and background sound levels in the area are already
elevated.
Airborne Acoustic Effects--Pinnipeds that occur near the project
site could be exposed to airborne sounds associated with pile driving
and removal that have the potential to cause behavioral harassment,
depending on their distance from pile driving activities. Cetaceans are
not expected to be exposed to airborne sounds that would result in
harassment as defined under the MMPA.
Airborne noise would primarily be an issue for pinnipeds that are
swimming or hauled out near the project site within the range of noise
levels elevated above the acoustic criteria. We recognize that
pinnipeds in the water could be exposed to airborne sound that may
result in behavioral harassment when looking with their heads above
water. 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 the area and move
further from the source. However, these animals would likely previously
have been `taken' because of exposure to underwater sound above the
behavioral harassment thresholds, which are generally larger than those
associated with airborne sound. There are no haulouts near the project
sites. Thus, the behavioral harassment of these animals is already
accounted for in these estimates of potential take. Therefore, we do
not believe that authorization of incidental take resulting from
airborne sound for pinnipeds is warranted, and airborne sound is not
discussed further here.
[[Page 48635]]
Marine Mammal Habitat Effects
WSDOT's proposed construction activities could have localized,
temporary impacts on marine mammal habitat, including prey, by
increasing in-water sound pressure levels and slightly decreasing water
quality. Increased noise levels may affect acoustic habitat (see
masking discussion above) and adversely affect marine mammal prey in
the vicinity of the project areas (see discussion below). During impact
and vibratory pile driving or removal, elevated levels of underwater
noise would ensonify the project areas where both fishes and mammals
occur and could affect foraging success. Additionally, marine mammals
may avoid the area during construction, however, displacement due to
noise is expected to be temporary and is not expected to result in
long-term effects to the individuals or populations. Construction
activities are of short duration and would likely have temporary
impacts on marine mammal habitat through increases in underwater and
airborne sound.
A temporary and localized increase in turbidity near the seafloor
would occur in the immediate area surrounding the area where piles are
installed or removed. In general, turbidity associated with pile
installation is localized to about a 25-ft (7.6-m) radius around the
pile (Everitt et al., 1980). The sediments of the project site will
settle out rapidly when disturbed. Cetaceans are not expected to be
close enough to the pile driving areas to experience effects of
turbidity, and any pinnipeds could avoid localized areas of turbidity.
Local currents are anticipated to disburse any additional suspended
sediments produced by project activities at moderate to rapid rates
depending on tidal stage. Therefore, we expect the impact from
increased turbidity levels to be discountable to marine mammals and do
not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat
The area likely impacted by the project is relatively small
compared to the available habitat in Puget Sound. The area is highly
influenced by anthropogenic activities. The total seafloor area
affected by pile installation and removal is a small area compared to
the vast foraging area available to marine mammals in the area. At
best, the impact area provides marginal foraging habitat for marine
mammals and fishes. Furthermore, pile driving and removal at the
project site would not obstruct long-term movements or migration of
marine mammals.
Avoidance by potential prey (i.e., fish or, in the case of
transient killer whales, other marine mammals) of the immediate area
due to the temporary loss of this foraging habitat is also possible.
The duration of fish and marine mammal avoidance of this area after
pile driving stops is unknown, but a rapid return to normal
recruitment, distribution, and behavior is anticipated. Any behavioral
avoidance by fish or marine mammals of the disturbed area would still
leave significantly large areas of fish and marine mammal foraging
habitat in the nearby vicinity.
In-Water Construction Effects on Potential Prey--Sound may affect
marine mammals through impacts on the abundance, behavior, or
distribution of prey species (e.g., crustaceans, cephalopods, fish,
zooplankton, other marine mammals). Marine mammal prey varies by
species, season, and location. Here, we describe studies regarding the
effects of noise on known marine mammal prey other than other marine
mammals (which have been discussed earlier).
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay,
2009). Depending on their hearing anatomy and peripheral sensory
structures, which vary among species, fishes hear sounds using pressure
and particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
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 on fish; several are based on
studies in support of large, multiyear bridge construction projects
(e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Several
studies have demonstrated that impulse sounds might affect the
distribution and behavior of some fishes, potentially impacting
foraging opportunities or increasing energetic costs (e.g., Fewtrell
and McCauley, 2012; Pearson et al., 1992; Skalski et al., 1992;
Santulli et al., 1999; Paxton et al., 2017). However, some studies have
shown no or slight reaction to impulse sounds (e.g., Pena et al., 2013;
Wardle et al., 2001; Jorgenson and Gyselman, 2009; Popper et al.,
2015).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The most likely impact to fishes from pile driving and removal and
construction activities at the project areas 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.
Construction activities, in the form of increased turbidity, have
the potential to adversely affect forage fish in the project areas.
Forage fish form a significant prey base for many marine mammal species
that occur in the project areas. Increased turbidity is expected to
occur in the immediate vicinity (on the order of 10 ft (3 m) or less)
of construction activities. However, suspended sediments and
particulates are expected to dissipate quickly within a single tidal
cycle. Given the limited area affected and high tidal dilution rates
any effects on forage fish are expected to be minor or negligible.
Finally, exposure to turbid waters from construction activities is not
expected to be different from the current exposure; fish and marine
mammals in Eagle Harbor are routinely exposed to substantial levels of
suspended
[[Page 48636]]
sediment from natural and anthropogenic sources.
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 actions
are not likely to have a permanent, adverse effect on any fish habitat,
or populations of fish species. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large areas of fish and
marine mammal foraging habitat in the nearby vicinity. Thus, we
conclude that impacts of the specified activities are not likely to
have more than short-term adverse effects on any prey habitat or
populations of prey species. Further, any impacts to marine mammal
habitat are not expected to result in significant or long-term
consequences for individual marine mammals, or to contribute to adverse
impacts on their populations.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. 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).
Authorized takes would primarily be by Level B harassment (in the
form of behavioral disturbance and TTS), as use of the acoustic sources
(i.e., vibratory or impact pile driving and removal) have the potential
to result in disruption of behavioral patterns and cause a temporary
loss in hearing sensitivity for individual marine mammals. There is
also some potential for auditory injury (Level A harassment) to result
for porpoises and harbor seals because predicted auditory injury zones
are larger. The proposed mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent
practicable.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the proposed take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) Acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the proposed take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur PTS of some degree (equated to Level A
harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (rms SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above rms SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources.
WSDOT's proposed activities includes the use of continuous
(vibratory hammer) and impulsive (impact hammer) sources, and therefore
the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different marine mammal groups
(based on hearing sensitivity) as a result of exposure to noise from
two different types of sources (impulsive or non-impulsive). WSDOT's
activities include the use of impulsive (impact hammer) and non-
impulsive (vibratory hammer) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
[[Page 48637]]
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI, 2013). However, ANSI defines peak sound pressure as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project areas is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected by sound generated by the
primary components of the project (i.e., impact and vibratory pile
driving).
In order to calculate distances to the Level A harassment and Level
B harassment thresholds for the methods and piles being used in these
projects, NMFS used acoustic monitoring data from previous pile driving
at the Bainbridge Island Ferry Terminal (impact installation of 24-in
steel piles) and Eagle Harbor Maintenance Facility (impact installation
of 30-in steel piles), as well as pile driving at other locations
within Puget Sound to develop source levels for the various pile types,
sizes, and methods for the two projects (Table 6). A source level for
vibratory driving of 18-in steel piles is not available so it is
conservatively assumed to be equivalent to the source level for 24-in
steel piles.
Table 6--Expected Project Sound Source Levels
----------------------------------------------------------------------------------------------------------------
Source level
Pile type and size (in) Method Source level (dB re measurement Reference
1 [mu]Pa) distance (m)
----------------------------------------------------------------------------------------------------------------
12-in timber..................... Vibratory removal.. 152 dB rms......... 10 Greenbusch Group
(2018).
18-in and 24-in steel............ Vibratory 166 dB rms......... 10 WSDOT (2020) \1\.
installation and
removal.
30-in steel...................... Vibratory 176 dB rms......... 6 WSDOT (2020) \1\.
installation and
removal.
36-in steel...................... Vibratory 184 dB rms......... 10 WSDOT (2020) \1\.
installation.
24-in steel...................... Impact installation 206 dB peak; 179 dB 10 WSDOT (2020) \1\.
SEL; 195 dB rms.
30-in steel...................... Impact installation 194 dB peak; 182 dB 10 WSDOT (2020) \1\.
SEL; 184 dB rms.
36-in steel...................... Impact installation 205 dB peak; 178 dB 10 WSDOT (2020) \1\.
SEL; 191 dB rms.
----------------------------------------------------------------------------------------------------------------
\1\ WSDOT Biological Assessment Manual Table 7-15.
Level B Harassment Zones
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. The general formula for underwater TL is:
TL = B * Log10 (R1/R2)
Where:
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement
The recommended TL coefficient for most nearshore environments is
the practical spreading value of 15. This value results in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions, which is the most appropriate
assumption for WSDOT's proposed activities in the absence of specific
modelling. The Level B harassment zones for WSDOT's proposed activities
are shown in Table 7.
Level A Harassment Zones
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically
[[Page 48638]]
going to be overestimates of some degree, which may result in an
overestimate of potential take by Level A harassment. However, this
optional tool offers the best way to estimate isopleth distances when
more sophisticated modeling methods are not available or practical. For
stationary sources such as pile installation and removal, the optional
User Spreadsheet tool predicts the distance at which, if a marine
mammal remained at that distance for the duration of the activity, it
would be expected to incur PTS. The isopleths generated by the User
Spreadsheet used the same TL coefficient as the Level B harassment zone
calculations (i.e., the practical spreading value of 15). Inputs used
in the User Spreadsheet (e.g., number of piles per day, duration and/or
strikes per pile) are presented in Tables 1 and 2, and the resulting
isopleths are reported below in Table 7.
Table 7--Level A Harassment and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m)
Pile size/type Pile driving -------------------------------------------------------------------------------- Level B harassment
method LF cetaceans MF cetaceans HF cetaceans Phocids Otariids zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-in timber.................... Vibratory removal. 4.1 0.4 6.1 2.5 0.2 \a\ 1,360
18-in steel..................... Vibratory 23.4 2.1 34.5 14.2 1.0 \a\ 11,659
installation/
removal.
24-in steel..................... Vibratory 27.1 2.4 40.1 16.5 1.2 \a\ 11,659
installation/
removal.
30-in steel..................... Vibratory 65.1 5.8 96.2 39.5 2.8 \a\ \b\ 32,470
installation/
removal.
36-in steel..................... Vibratory 485.1 43.0 717.2 294.9 20.7 \a\ \b\ 184,785
installation.
24-in steel..................... Impact 784.8 27.9 934.8 420.0 30.6 \c\ 2,154
installation.
30-in steel..................... Impact 1,359.6 48.4 1,619.5 727.6 53.0 \c\ 2,154398
installation.
36-in steel..................... Impact 795.9 28.3 948.0 425.9 31.0 \c\ 2,1541,166
installation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Distance to 120 dB rms threshold.
\b\ Distance to Level B harassment threshold without obstruction; however for these projects, 13,345 m is the maximum in-water distance until land is
reached.
\c\ Distance to 160 dB rms threshold.
Marine Mammal Occurrence and Take Calculation and Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information, that
will inform the quantitative estimate of the take that is reasonably
likely to occur and proposed for authorization. Unless otherwise
specified, the term ``pile driving'' in this section, and all following
sections, may refer to either pile installation or removal. WSDOT first
estimated take for both projects using the areas ensonified above the
Level B harassment threshold and density estimates for marine mammals
in Puget Sound. Density estimates for all species except harbor
porpoises were from the U.S. Navy's Marine Species Density Database
(MSDD) for the Northwest Training and Testing (NWTT) Study Area (U.S.
Navy, 2019). For harbor porpoises, WSDOT used the density estimate from
Evenson (2016) as it was considered more conservative than the density
estimate for harbor porpoises from the NWTT MSDD. However, for all
species except harbor seals and harbor porpoises, WSDOT did not
consider the resulting take estimates to be realistic (i.e., either
over- or underestimated take). Instead, WSDOT compiled monitoring
results from pile driving between August 2017 and February 2021 at the
Seattle Ferry Terminal Multimodal Project at Colman Dock (WSDOT 2021)
(Table 8). Because the Level B harassment zones from vibratory pile
driving at Colman Dock extended to or near the Bainbridge Island
shoreline, and because the Level B harassment zones from vibratory pile
driving at the Bainbridge Ferry Terminal and Eagle Harbor Maintenance
Facility extend to the shoreline, WSDOT considered the monitoring
results from the Seattle Multimodal Project to be the most relevant and
comprehensive sightings data available for the project areas. Based on
the Seattle Multimodal Project monitoring results, WSDOT used their
best professional judgement to estimate the number of marine mammals
that may be taken incidental to the proposed activities.
NMFS has carefully reviewed WSDOT's analysis and concludes that it
represents an appropriate and accurate method for estimating incidental
take caused by WSDOT's activities.
Table 8--Marine Mammal Density and Sightings
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average
Species Density/km\2\ Sightings sightings/day Maximum one- Take requested
total (372 days) day sightings
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Seal.................................. 3.91 1,939 5.21 43 Yes.
Northern Elephant Seal....................... \1\ 0.0 1 0.003 1 Yes.
California Sea Lion.......................... 0.0152-0.2211 2,625 7.05 38 Yes.
Steller Sea Lion............................. 0.0010-0.0478 100 0.27 10 Yes.
Unidentified pinniped........................ N/A 118 N/A 9 N/A.
Killer Whale Southern Resident............... 0.000009-0.007828 297 0.80 26 No.
Killer Whale Transient....................... 0.001582-0.002373 47 0.13 20 Yes.
[[Page 48639]]
Gray Whale................................... 0.000086 4 0.011 1 Yes.
Minke Whale.................................. 0.00045 1 0.003 1 Yes.
Unidentified large whale..................... N/A 2 N/A 1 N/A.
Unidentified small whale..................... N/A 10 N/A 9 N/A.
Harbor Porpoise.............................. 0.58 413 1.11 40 Yes.
Dall's Porpoise.............................. 0.00045 8 0.02 5 Yes.
Pacific White-sided Dolphin.................. 0.0 2 0.005 2 Yes.
Long-beaked Common Dolphin................... 0.0 2 0.005 1 Yes.
Common Bottlenose Dolphin.................... 0.0 6 0.02 2 Yes.
Unidentified dolphin/porpoise................ N/A 42 N/A 5 N/A.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale
WSDOT estimated that up to 20 gray whales could be taken by Level B
harassment from each project, for a total of 40 takes of gray whales by
Level B harassment. In consideration of the infrequent occurrence of
gray whales in the project areas, the proposed mitigation and
monitoring measures that WSDOT would be required to comply with,
including marine mammal monitoring and coordination with Orca Network
that would alert WSDOT to the presence of large whales in the project
area (see Proposed Mitigation), and given the size and visibility of
gray whales, WSDOT would be able to detect gray whales and stop work
before gray whales could enter the Level A harassment zones. Therefore,
it is unlikely that any gray whales would be taken by Level A
harassment. No take of gray whales by Level A harassment is requested
or proposed to be authorized.
Minke Whale
WSDOT estimated that up to 20 minke whales could be taken by Level
B harassment from each project, for a total of 40 takes of minke whales
by Level B harassment. Like gray whales, in consideration of the
infrequent occurrence of minke whales in the project areas, the
proposed mitigation and monitoring measures that WSDOT would be
required to comply with, including marine mammal monitoring and
coordination with Orca Network (see Proposed Mitigation), and given the
size and visibility of minke whales, WSDOT would be able to detect
minke whales and stop work before minke whales could enter the Level A
harassment zones. Therefore, it is unlikely that any minke whales would
be taken by Level A harassment. No take of minke whales by Level A
harassment is requested or proposed to be authorized.
Long-Beaked Common Dolphin
WSDOT estimated that up to 20 long-beaked common dolphins could be
taken by Level B harassment from each project, for a total of 40 takes
of long-beaked common dolphins by Level B harassment. The Level A
harassment zones for mid-frequency cetaceans are all less than 50 m.
Given the visibility of long-beaked common dolphins, WSDOT would be
able to cease pile driving before long-beaked common dolphins could
enter the Level A harassment zone. No take of long-beaked common
dolphins by Level A harassment is requested or proposed to be
authorized.
Bottlenose Dolphin
WSDOT estimated that up to 20 bottlenose dolphins could be taken by
Level B harassment from each project, for a total of 40 takes of
bottlenose dolphins by Level B harassment. The Level A harassment zones
for mid-frequency cetaceans are all less than 50 m. Given the
visibility of bottlenose dolphins, WSDOT would be able to cease pile
driving before bottlenose dolphins could enter the Level A harassment
zone. No take of bottlenose dolphins by Level A harassment is requested
or proposed to be authorized.
Pacific White-Sided Dolphin
WSDOT estimated that up to 20 Pacific white-sided dolphins could be
taken by Level B harassment from each project, for a total of 40 takes
of Pacific white-sided dolphins by Level B harassment. The Level A
harassment zones for mid-frequency cetaceans are all less than 50 m.
Given the visibility of long-beaked common dolphins, WSDOT would be
able to cease pile driving before long-beaked common dolphins could
enter the Level A harassment zone. No take of long-beaked common
dolphins by Level A harassment is requested or proposed to be
authorized.
Killer Whale (Transient)
WSDOT estimated that up to 60 transient killer whales could be
taken by Level B harassment from each project, for a total of 120 takes
of killer whales by Level B harassment. The Level A harassment zones
for mid-frequency cetaceans are all less than 50 m. Given the
visibility of killer whales, WSDOT would be able to cease pile driving
before killer whales could enter the Level A harassment zone. No take
of killer whales by Level A harassment is requested or proposed to be
authorized.
As stated above, no take of Southern Resident killer whales is
expected or proposed to be authorized.
Harbor Porpoise
To estimate the number of harbor porpoises that may be taken by
Level B harassment from the two projects, WSDOT calculated the area
ensonified above the Level B harassment threshold for each pile size,
type, and method for both projects. WSDOT then multiplied the estimated
density of harbor porpoises in the area (0.58 per km\2\; Evenson 2016)
by the ensonified area and the expected days of work for each project
element (Table 9).
[[Page 48640]]
Table 9--Estimated Take of Harbor Porpoises by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bainbridge Eagle Harbor
takes by Level takes by Level
Bainbridge Bainbridge Eagle Harbor Eagle Harbor B harassment B harassment
Pile size, type, and method ensonified days of work ensonified days of work by pile size, by pile size,
area (km\2\) area (km\2\) type, and type, and
method method
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-in timber vibratory.................................. 0.5 5 0.8 13 3 6
18-in steel vibratory................................... N/A 0 23.2 3 0 27
24-in steel vibratory................................... 2.3 2 23.2 3 3 40
30-in steel vibratory................................... 2.3 23 23.2 4 320 53
36-in steel vibratory................................... 2.3 6 23.2 4 84 53
24-in steel impact...................................... 0.9 13 0.87 3 17 2
30-in steel impact...................................... 0.4 2 N/A 0 3 0
36-in steel impact...................................... 0.9 6 0.87 1 8 1
-----------------------------------------------------------------------------------------------
Total............................................... .............. .............. .............. .............. 298 183
--------------------------------------------------------------------------------------------------------------------------------------------------------
The areas ensonified above the Level A harassment threshold for
high-frequency cetaceans has been omitted from the areas ensonified
above the Level B harassment threshold presented in Table 9. For impact
installation of 30-in steel piles, the Level A harassment zone for
high-frequency cetaceans is approximately 1,620 m. To estimate the
number of harbor porpoises that may be present within the Level A
harassment zone, WSDOT used the average sightings rate from the Seattle
Multimodal Project at Colman Dock (0.691 harbor porpoises per day;
Table 8) multiplied by the days of impact pile driving expected for
each project (27 days for the Bainbridge Project and 8 days for the
Eagle Harbor Project) to estimate that 19 and 6 harbor porpoises may be
taken by Level A harassment from the Bainbridge Project and Eagle
Harbor Project, respectively, for a total of 25 takes of harbor seals
by Level A harassment.
Dall's Porpoise
WSDOT estimated that up to 20 Dall's porpoises could be taken by
Level B harassment from each project, for a total of 40 takes of Dall's
porpoises by Level B harassment.
For impact installation of 30-in steel piles, the Level A
harassment zone for high-frequency cetaceans is approximately 1,620 m.
Dall's porpoises are considered rare in the project area and are
unlikely to be present within the Level A harassment zones but WSDOT
conservatively estimates that no more than 5 Dall's porpoises could
enter the Level A harassment zones of each project, for a total of 10
takes of Dall's porpoises by Level A harassment.
California Sea Lion
Over the course of 372 days of monitoring for the Seattle
Multimodal Project at Colman Dock, the average number of California sea
lions observed per day was 7.05 (Table 8). WSDOT used that average
sightings rate multiplied by the days of work for each project (57 days
for the Bainbridge Project and 31 days for the Eagle Harbor Project) to
estimate that 402 and 219 California sea lions may be taken by Level B
harassment from the Bainbridge Project and Eagle Harbor Project,
respectively, for a total of 621 takes of California sea lions by Level
B harassment.
The largest Level A harassment zone for otariid pinnipeds is 53 m.
WSDOT would be required to implement a 60 m shutdown zone for otariids
for all pile driving activities. At that close range, WSDOT would be
able to detect California sea lions and implement the required shutdown
measures before California sea lions could enter the Level A harassment
zone. Therefore, no takes of California sea lions by Level A harassment
are requested or proposed to be authorized.
Steller Sea Lion
WSDOT estimated that 180 Steller sea lions could be taken by Level
B harassment from each project, for a total of 360 takes of Steller sea
lions by Level B harassment. The largest Level A harassment zone for
otariid pinnipeds is 53 m. WSDOT would be required to implement a 60 m
shutdown zone for otariids for all pile driving activities. At that
close range, WSDOT would be able to detect Steller sea lions and
implement the required shutdown measures before Steller sea lions could
enter the Level A harassment zone. Therefore, no takes of Steller sea
lions by Level A harassment are requested or proposed to be authorized.
Harbor Seal
To estimate the number of harbor seals that may be taken by Level B
harassment from the two projects, WSDOT calculated the area ensonified
above the Level B harassment threshold for each pile size, type, and
method for both projects. WSDOT then multiplied the estimated density
of harbor seals in the area (3.91 per km\2\; Navy 2019) by the
ensonified area and the expected days of work for each project element
(Table 10). In total, WSDOT estimates that 3,450 harbor seals may be
taken by Level B harassment.
Table 10--Estimated Take of Harbor Seals by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bainbridge Eagle Harbor
Bainbridge Bainbridge Eagle Harbor Eagle Harbor takes by pile takes by pile
Pile size, type, and method ensonified days of work ensonified days of work size, type, size, type,
area (km\2\) area (km\2\) and method and method
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-in timber vibratory.................................. 1.5 5 1.6 13 30 81
18-in steel vibratory................................... N/A 0 24.1 3 0 188
24-in steel vibratory................................... 24.0 2 24.1 3 188 283
30-in steel vibratory................................... 24.0 23 24.1 4 2,158 377
36-in steel vibratory................................... 24.0 6 24.1 4 563 377
24-in steel impact...................................... 2.0 13 1.66 3 102 20
[[Page 48641]]
30-in steel impact...................................... 1.3 2 N/A 0 10 0
36-in steel impact...................................... 2.0 6 1.66 1 47 7
-----------------------------------------------------------------------------------------------
Total............................................... .............. .............. .............. .............. 2,117 1,333
--------------------------------------------------------------------------------------------------------------------------------------------------------
The areas ensonified above the Level A harassment threshold for
high-frequency cetaceans has been omitted from the areas ensonified
above the Level B harassment threshold presented in Table 10. For
impact installation of 30-in steel piles, the Level A harassment zone
for phocid pinnipeds is approximately 728 m. To estimate the number of
harbor seals that may be present within the Level A harassment zone,
WSDOT used the average sightings rate from the Seattle Multimodal
Project at Colman Dock (5.21 harbor seals per day; Table 8) multiplied
by the days of impact pile driving expected for each project (27 days
for the Bainbridge Project and 8 days for the Eagle Harbor Project) to
estimate that 141 and 42 harbor seals may be taken by Level A
harassment from the Bainbridge Project and Eagle Harbor Project,
respectively, for a total of 183 takes of harbor seals by Level A
harassment.
Northern Elephant Seal
Individual elephant seals have occasionally been reported in
central Puget Sound (e.g., Orca Network, 2020) but are considered rare
in the project areas. WSDOT estimated that up to 10 northern elephant
seals could be taken by Level B harassment from each project, for a
total of 20 takes of northern elephant seals by Level B harassment. The
largest Level A harassment zone (728 m) occurs during impact
installation of 30-in steel pipe piles (Table 7). It is unlikely that
northern elephant seals would be found within this zone, and even more
unlikely that northern elephant seals would be found within the Level A
harassment zones for vibratory pile driving (up to 295 m). However,
even if northern elephant seals were encountered in the project areas,
at that close range, WSDOT would be able to detect them and implement
the required shutdown measures before any northern elephant seals could
enter the Level A harassment zones. Therefore, no take of northern
elephant seals by Level A harassment is requested or proposed to be
authorized.
Table 11--Proposed Take of Marine Mammals by Level A and Level B Harassment From the Bainbridge Project by
Species and Stock
----------------------------------------------------------------------------------------------------------------
Proposed take Proposed take
Species Stock by Level B by Level A
harassment harassment
----------------------------------------------------------------------------------------------------------------
Gray whale.................................... Eastern North Pacific........... 20 0
Minke whale................................... California/Oregon/Washington.... 20 0
Killer whale.................................. West Coast Transient............ 60 0
Bottlenose dolphin............................ California Coastal.............. 20 0
Long-beaked common dolphin.................... California...................... 20 0
Pacific white-sided dolphin................... ................................ 20 0
Harbor porpoise............................... Washington Inland Waters........ 298 19
Dall's porpoise............................... California/Oregon/Washington.... 20 5
California sea lion........................... U.S............................. 402 0
Steller sea lion.............................. Eastern......................... 180 0
Northern elephant seal........................ California Breeding............. 10 0
Harbor seal................................... Washington Northern Inland 2,117 141
Waters.
----------------------------------------------------------------------------------------------------------------
Table 12--Proposed Take of Marine Mammals by Level A and Level B Harassment From the Eagle Harbor Project by
Species and Stock
----------------------------------------------------------------------------------------------------------------
Proposed take Proposed take
Species Stock by Level B by Level A
harassment harassment
----------------------------------------------------------------------------------------------------------------
Gray whale.................................... Eastern North Pacific........... 20 0
Minke whale................................... California/Oregon/Washington.... 20 0
Killer whale.................................. West Coast Transient............ 60 0
Bottlenose dolphin............................ California Coastal.............. 20 0
Long-beaked common dolphin.................... California...................... 20 0
Pacific white-sided dolphin................... ................................ 20 0
Harbor porpoise............................... Washington Inland Waters........ 183 6
Dall's porpoise............................... California/Oregon/Washington.... 20 5
California sea lion........................... U.S............................. 219 0
Steller sea lion.............................. Eastern......................... 180 0
Northern elephant seal........................ California Breeding............. 10 0
Harbor seal................................... Washington Northern Inland 1,333 42
Waters.
----------------------------------------------------------------------------------------------------------------
[[Page 48642]]
Table 13--Total Proposed Take of Marine Mammals by Level A and Level B Harassment, by Species and Stock and
Percent of Take by Stock
----------------------------------------------------------------------------------------------------------------
Total proposed Total proposed
Species Stock take by Level take by Level Total proposed Percent of
A harassment B harassment take stock
----------------------------------------------------------------------------------------------------------------
Gray whale.................... Eastern North 0 40 40 0.2
Pacific.
Minke whale................... California/ 0 40 40 11.0
Oregon/
Washington.
Killer whale.................. West Coast 0 120 120 34.4
Transient.
Bottlenose dolphin............ California 0 40 40 8.8
Coastal.
Long-beaked common dolphin.... California...... 0 40 40 3.2
Pacific white-sided dolphin... California/ 0 40 40 0.2
Oregon/
Washington.
Harbor porpoise............... Washington 25 481 506 5.0
Inland Waters.
Dall's porpoise............... California/ 10 40 50 0.3
Oregon/
Washington.
California sea lion........... U.S............. 0 621 621 0.24
Steller sea lion.............. Eastern......... 0 360 360 0.83
Northern elephant seal........ California 0 20 20 0.01
Breeding.
Harbor seal................... Washington 183 3,450 3,633 32.9
Northern Inland
Waters.
----------------------------------------------------------------------------------------------------------------
Proposed Mitigation
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 the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). 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 the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost and impact on
operations.
Shutdown Zones
Before the commencement of in-water construction activities, WSDOT
would establish shutdown zones for all activities. The purpose of a
shutdown zone is generally to define an area within which shutdown of
the activity would occur upon sighting of a marine mammal (or in
anticipation of an animal entering the defined area). Pile driving
would also not commence until all marine mammals are clear of their
respective shutdown zones. Shutdown zones are established in
consideration of the Level A harassment zones and therefore typically
vary based on the activity type and marine mammal hearing group.
However, rather than establishing different shutdown zones for each
hearing group for each project element, WSDOT proposed to simplify the
shutdown zones and implement only 1 or 2 shutdown zones for each
hearing group across all project elements (Table 14). For example, the
720 m shutdown zone proposed to be implemented for low-frequency and
high-frequency cetaceans for all vibratory pile driving activities
encompasses both the largest Level A harassment zone for high-frequency
cetaceans (717.2 m; see Table 7) and the largest Level A harassment
zone for low-frequency cetaceans (485.1 m; see Table 7). This
conservatively protects animals in both hearing groups, simplifies
analysis and monitoring, and presents minimal risks to implementing the
project, as marine mammals in these hearing groups are unlikely to be
present within 720 m of the construction site during pile driving
activities. For impact pile driving, WSDOT proposes to retain the 720 m
shutdown zone for high-frequency cetaceans but increase the shutdown
zone for low-frequency cetaceans to 2,175 m which encompasses the
largest Level B harassment zone for impact pile driving, and is also
the proposed shutdown zone for preventing take of unauthorized species
(e.g., Southern Resident killer whales, humpback whales) (Table 14).
The Level A harassment zones for high-frequency cetaceans from impact
pile driving are all greater than 720 m (Table 7), thus any high-
frequency cetacean that enters the Level A harassment zone beyond 720 m
would be recorded as taken by Level A harassment.
At minimum, the shutdown zone for all hearing groups and all
activities would be 10 m. For in-water heavy machinery work other than
pile driving (e.g., standard barges, etc.), if a marine mammal comes
within 10 m, operations would cease and vessels would reduce speed to
the minimum level required to maintain steerage and safe working
conditions. This type of work could include, for example, the movement
of the barge to the pile location or positioning of the pile on the
substrate via a crane.
WSDOT would also establish shutdown zones for all marine mammals
for which take has not been authorized or for which incidental take has
been authorized but the authorized number of takes has been met. These
zones are equivalent to the Level B harassment zones for each activity
(see Table 14).
WSDOT would also implement shutdown measures for Southern Resident
killer whales and humpback whales. If Southern Resident killer whales
or humpback whales are sighted within the vicinity of the project areas
and are approaching the Level B harassment zone (see Table 14), WSDOT
would shut down the pile driving equipment to avoid possible take of
these species. If a killer whale
[[Page 48643]]
approaches the Level B harassment zone during pile driving, and it is
unknown whether it is a Southern Resident killer whale or a transient
killer whale, it would be assumed to be a Southern Resident killer
whale and WSDOT would implement the shutdown measure.
If a Southern Resident killer whale, unidentified killer whale, or
humpback whale enters the Level B harassment zone undetected, in-water
pile driving would be suspended until the whale exits the Level B
harassment zone, or 15 minutes have elapsed with no sighting of the
animal, to avoid further Level B harassment.
Table 14--Shutdown Zones for Pier 58 Reconstruction
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown zone (m)
-----------------------------------------------------------------------------------------------
Southern
resident
killer whales,
Pile type and method humpback
LF cetacean MF cetacean HF cetacean Phocids Otariids whales, and
other
unauthorized
species
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-in timber vibratory.................................. 720 60 720 60 60 2,175
18-in steel vibratory................................... 720 60 720 60 60 \a\ 13,345
24-in steel vibratory................................... 720 60 720 60 60 \a\ 13,345
30-in steel vibratory................................... 720 60 720 60 60 \a\ 13,345
36-in steel vibratory................................... 720 60 720 60 60 \a\ 13,345
24-in steel impact...................................... 2,175 60 720 60 60 2,175
30-in steel impact...................................... 2,175 60 720 60 60 2,175
36-in steel impact...................................... 2,175 60 720 60 60 2,175
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 13,345 m is the maximum distance sound can travel before reaching land.
Protected Species Observers
The placement of protected species observers (PSOs) during all pile
driving activities (described in the Proposed Monitoring and Reporting
section) would ensure that the entire shutdown zone is visible. Should
environmental conditions deteriorate such that the entire shutdown zone
would not be visible (e.g., fog, heavy rain), pile driving would be
delayed until the PSO is confident marine mammals within the shutdown
zone could be detected.
Monitoring for Level A and Level B Harassment
PSOs would monitor the Level B harassment zones to the extent
practicable, and all of the Level A harassment zones. Monitoring zones
provide utility for observing by establishing monitoring protocols for
areas adjacent to the shutdown zones. Monitoring zones enable observers
to be aware of and communicate the presence of marine mammals in the
project areas outside the shutdown zones and thus prepare for a
potential cessation of activity should the animal enter the shutdown
zone.
Pre-Activity Monitoring
Prior to the start of daily in-water construction activity, or
whenever a break in pile driving of 30 minutes or longer occurs, PSOs
would observe the shutdown and monitoring zones for a period of 30
minutes. The shutdown zone would be considered cleared when a marine
mammal has not been observed within the zone for that 30-minute period.
If a marine mammal is observed within the shutdown zones listed in
Table 14, pile driving activity would be delayed or halted. If pile
driving is delayed or halted due to the presence of a marine mammal,
the activity would not commence or resume until either the animal has
voluntarily exited and been visually confirmed beyond the shutdown
zones or 15 minutes have passed without re-detection of the animal.
When a marine mammal for which Level B harassment take is authorized is
present in the Level B harassment zone, activities would begin and
Level B harassment take would be recorded. If work ceases for more than
30 minutes, the pre-activity monitoring of the shutdown zones would
commence. A determination that the shutdown zone is clear must be made
during a period of good visibility (i.e., the entire shutdown zone and
surrounding waters must be visible to the naked eye).
Coordination With Local Marine Mammal Research Network
Prior to the start of pile driving for the day, the PSOs would
contact the Orca Network to find out the location of the nearest marine
mammal sightings. The Local Marine Mammal Research Network consists of
a list of over 600 (and growing) residents, scientists, and government
agency personnel in the United States and Canada. Sightings are called
or emailed into the Orca Network and immediately distributed to other
sighting networks including: the NMFS Northwest Fisheries Science
Center, the Center for Whale Research, Cascadia Research, the Whale
Museum Hotline, and the British Columbia Sightings Network.
Sightings information collected by the Orca Network includes
detection by hydrophone. The SeaSound Remote Sensing Network is a
system of interconnected hydrophones installed in the marine
environment of Haro Strait (west side of San Juan Island) to study orca
communication, in-water noise, bottom fish ecology, and local climatic
conditions. A hydrophone at the Port Townsend Marine Science Center
measures average in-water sound levels and automatically detects
unusual sounds. These passive acoustic devices allow researchers to
hear when different marine mammals come into the region. This acoustic
network, combined with the volunteer visual sighting network allows
researchers to document presence and location of various marine mammal
species.
Soft Start
Soft-start procedures are used to provide additional protection to
marine mammals by providing warning and/or giving marine mammals a
chance to leave the area prior to the hammer operating at full
capacity. For impact pile driving, contractors would be required to
provide an initial set of three strikes from the hammer at reduced
energy, followed by a 30-second waiting period, then two subsequent
reduced-
[[Page 48644]]
energy strike sets. Soft start would be implemented at the start of
each day's impact pile driving and at any time following cessation of
impact pile driving for a period of 30 minutes or longer.
Bubble Curtain
A bubble curtain would be employed during impact installation or
proofing of steel piles, unless the piles are driven in the dry, or
water is less than 3 ft (0.9 m) in depth. A noise attenuation device
would not be required during vibratory pile driving. If a bubble
curtain or similar measure is used, it would distribute air bubbles
around 100 percent of the piling perimeter for the full depth of the
water column. Any other attenuation measure would be required to
provide 100 percent coverage in the water column for the full depth of
the pile. The lowest bubble ring would be in contact with the mudline
for the full circumference of the ring. The weights attached to the
bottom ring would ensure 100 percent mudline contact. No parts of the
ring or other objects would prevent full mudline contact.
Based on our evaluation of the WSDOT's proposed measures, as well
as other measures considered by NMFS, NMFS has preliminarily determined
that the proposed mitigation measures provide the means of effecting
the least practicable impact on the affected 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 IHA 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
authorizations 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 while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring during pile driving activities would be
conducted by PSOs meeting NMFS' standards and in a manner consistent
with the following:
Independent PSOs (i.e., not construction personnel) who
have no other assigned tasks during monitoring periods would be used;
At least one PSO would have prior experience performing
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
Other PSOs may substitute education (degree in biological
science or related field) or training for experience; and
Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator would be designated. The lead
observer would be required to have prior experience working as a marine
mammal observer during construction.
PSOs would have the following additional qualifications:
Ability to conduct field observations and collect data
according to assigned protocols;
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
During impact driving of all steel piles, and during vibratory
removal of timber piles, WSDOT would have three PSOs stationed to
monitor the project area: one at the construction site, one across
Eagle Harbor looking toward the construction site, and one on board the
Seattle-Bainbridge ferry. For vibratory driving of all steel piles,
WSDOT would have five PSOs to monitor the project area: three at the
locations described for impact pile driving, with one additional PSO
stationed on the Seattle waterfront and one stationed on Alki Beach
looking west toward Bainbridge Island.
Monitoring would be conducted 30 minutes before, during, and 30
minutes after all in water construction activities. In addition,
observers would record all incidents of marine mammal occurrence,
regardless of distance from activity, and would document any behavioral
reactions in concert with distance from piles being driven or removed.
Pile driving activities include the time to install or remove a single
pile or series of piles, as long as the time elapsed between uses of
the pile driving equipment is no more than 30 minutes.
Reporting
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving activities, or 60
days prior to a requested date of issuance of any future IHAs for the
project, or other projects at the same location, whichever comes first.
The marine mammal report would include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report would include:
Dates and times (begin and end) of all marine mammal
monitoring;
Construction activities occurring during each daily
observation period, including: (a) How many and what type of piles were
driven or removed and the
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method (i.e., impact or vibratory); and (b) the total duration of time
for each pile (vibratory driving) number of strikes for each pile
(impact driving);
PSO locations during marine mammal monitoring; and
Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
For each observation of a marine mammal, the following would be
reported:
Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting;
Time of sighting;
Identification of the animal(s) (e.g., genus/species,
lowest possible taxonomic level, or unidentified), PSO confidence in
identification, and the composition of the group if there is a mix of
species;
Distance and location of each observed marine mammal
relative to the pile being driven or hole being drilled for each
sighting;
Estimated number of animals (min/max/best estimate);
Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity (e.g., no response or changes in behavioral state such as
ceasing feeding, changing direction, flushing, or breaching);
Number of marine mammals detected within the harassment
zones, by species; and
Detailed information about implementation of any
mitigation (e.g., shutdowns and delays), a description of specified
actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
reports would constitute the final reports. If comments are received, a
final report addressing NMFS' comments would be required to be
submitted within 30 days after receipt of comments. All PSO datasheets
and/or raw sighting data would be submitted with the draft marine
mammal report.
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, WSDOT would report the
incident to the Office of Protected Resources (OPR)
([email protected]), NMFS and to the West Coast Region
(WCR) regional stranding coordinator as soon as feasible. If the death
or injury was clearly caused by the specified activity, WSDOT would
immediately cease the specified activities until NMFS is able to review
the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of the IHAs. WSDOT would not resume their activities until notified by
NMFS.
The report would include the following information:
1. Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
2. Species identification (if known) or description of the
animal(s) involved;
3. Condition of the animal(s) (including carcass condition if the
animal is dead);
4. Observed behaviors of the animal(s), if alive;
5. If available, photographs or video footage of the animal(s); and
6. General circumstances under which the animal was discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact 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 (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 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 harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338;
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
Pile driving activities from the Bainbridge and Eagle Harbor
Projects have the potential to disturb or displace marine mammals.
Specifically, the project activities may result in take, in the form of
Level A and Level B harassment, from underwater sounds generated from
pile driving. Potential takes could occur if individuals are present in
the ensonified zone when these activities are underway.
The takes from Level A and Level B harassment would be due to
potential behavioral disturbance, TTS, and PTS. No serious injury or
mortality is anticipated given the nature of the activities and
measures designed to minimize the possibility of injury to marine
mammals. The potential for harassment is minimized through the
construction method and the implementation of the planned mitigation
measures (see Proposed Mitigation section).
To avoid repetition, the majority of our analysis applies to all
the species listed in Table 3, given that the anticipated effects of
these projects on different marine mammal stocks are expected to be
relatively similar in nature. Where there are special circumstances for
a species or stock (e.g., gray whales), they are included as a separate
subsection below.
NMFS has identified key factors which may be employed to assess the
level of analysis necessary to conclude whether potential impacts
associated with a specified activity should be considered negligible.
These include (but are not limited to) the type and magnitude of
taking, the amount and importance of the available habitat for the
species or stock that is affected, the duration of the anticipated
effect to the species or stock, and the status of the species or stock.
The following factors support negligible impact determinations for all
affected stocks.
Take by Level A harassment is proposed for three species (harbor
seals, harbor porpoise, and Dall's porpoise) to account for the
possibility that an animal could enter a Level A harassment zone prior
to detection, and remain within that zone for a duration long enough to
incur PTS. Any take by Level A harassment is expected to arise from, at
most, a small degree of PTS, i.e., minor degradation of hearing
capabilities within regions of hearing that align most completely with
the
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energy produced by impact pile driving (i.e., the low-frequency region
below 2 kilohertz (kHz)), not severe hearing impairment or impairment
within the ranges of greatest hearing sensitivity. Animals would need
to be exposed to higher levels and/or longer duration than are expected
to occur here in order to incur any more than a small degree of PTS.
Two of the 3 species for which Level A harassment is proposed to be
authorized are high-frequency cetaceans (harbor porpoise and Dall's
porpoise), and the hearing ability of the third species for which Level
A harassment is proposed to be authorized (harbor seal) below 2 kHz is
also poor (NMFS, 2018). Given the hearing ranges of these three
species, PTS incurred at the low frequencies of pile driving noise
would not interfere either with conspecific communication or
echolocation, and therefore would not be expected to impact on the
survival or reproductive abilities of the affected individuals, let
alone the stock or population.
As described above, NMFS expects that marine mammals would likely
move away from an aversive stimulus, especially at levels that would be
expected to result in PTS, given sufficient notice through use of soft
start. WSDOT would also be required to shut down pile driving
activities if marine mammals approach within hearing group-specific
zones (see Table 14), further minimizing the likelihood and degree of
PTS that would be incurred. Even absent mitigation, no serious injury
or mortality from construction activities is anticipated or proposed to
be authorized.
Effects on individuals that are taken by Level B harassment in the
form of behavioral disruption, on the basis of reports in the
literature as well as monitoring from other similar activities, will
likely be limited to reactions such as avoidance, increased swimming
speeds, increased surfacing time, or decreased foraging (if such
activity were occurring) (e.g., Thorson and Reyff 2006). Most likely,
individuals would simply move away from the sound source and
temporarily avoid the area where pile driving is occurring. If sound
produced by project activities is sufficiently disturbing, animals are
likely to simply avoid the area while the activities are occurring,
particularly as the project is located in a busy harbor with high
amounts of vessel traffic, including large ferry boats. We expect that
any avoidance of the project areas by marine mammals would be temporary
in nature and that any marine mammals that avoid the project areas
during construction would not be permanently displaced. Short-term
avoidance of the project areas and energetic impacts of interrupted
foraging or other important behaviors is unlikely to affect the
reproduction or survival of individual marine mammals, and the effects
of behavioral disturbance on individuals is not likely to accrue in a
manner that would affect the rates of recruitment or survival of any
affected stock.
Additionally, and as noted previously, some subset of the
individuals that are behaviorally harassed could also simultaneously
incur some small degree of TTS for a short duration of time. However,
since the hearing sensitivity of individuals that incur TTS is expected
to recover completely within minutes to hours, it is unlikely that the
brief hearing impairment would affect the individual's long-term
ability to forage and communicate with conspecifics, and would
therefore not likely impact reproduction or survival of any individual
marine mammal, let alone adversely affect rates of recruitment or
survival of the species or stock.
The projects are also not expected to have significant adverse
effects on affected marine mammals' habitats. The project activities
will not modify existing marine mammal habitat for a significant amount
of time. The activities may cause some fish to leave the area 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 (with no known particular
importance to marine mammals), the impacts to marine mammal habitat are
not expected to cause significant or long-term negative consequences.
Aside from the biologically important area (BIA) for gray whales
described below, there are no known areas of importance for other
marine mammals, such as feeding or pupping areas, in the project area.
For all species and stocks, take would occur within a limited,
relatively confined area (Eagle Harbor within central Puget Sound) of
the stocks' ranges. Given the availability of suitable habitat nearby,
any displacement of marine mammals from the project areas is not
expected to affect marine mammals' fitness, survival, and reproduction
due to the limited geographic area that will be affected in comparison
to the much larger habitat for marine mammals in Puget Sound. Level A
harassment and Level B harassment will be reduced to the level of least
practicable adverse impact to the marine mammal species or stocks and
their habitat through use of mitigation measures described herein. Some
individual marine mammals in the project areas may be present and be
subject to repeated exposure to sound from pile driving on multiple
days. However, these individuals would likely return to normal behavior
during gaps in pile driving activity. Eagle Harbor is a busy harbor and
monitoring reports from previous in-water pile driving activities along
the nearby Seattle waterfront (e.g., WSDOT, 2022) indicate that marine
mammals continue to remain in the greater project area throughout pile
driving activities. Therefore, any behavioral effects of repeated or
long duration exposures are not expected to negatively affect survival
or reproductive success of any individuals. Thus, even repeated Level B
harassment of some small subset of an overall stock is unlikely to
result in any effects on rates of reproduction and survival of the
stock.
Gray Whales
Puget Sound is part of a BIA for migrating gray whales
(Calambokidis et al., 2015). While Eagle Harbor is included in the BIA,
gray whales typically remain further north in Puget Sound, primarily in
the waters around Whidbey Island (Calambokidis et al., 2018). Gray
whales are rarely observed in central Puget Sound, and have never been
documented inside Eagle Harbor. Therefore, even though the project
areas overlap with the BIA, the infrequent occurrence of gray whales
suggests that the projects would have minimal, if any, impact on the
migration of gray whales in the BIA, and would therefore not affect
reproduction or survival.
There is an ongoing UME for gray whales (see the Description of
Marine Mammals in the Area of Specified Activities section of this
notice). However, we do not expect the takes estimated to occur and
proposed for authorization to exacerbate or compound upon this ongoing
UME. As noted previously, no Level A harassment, serious injury, or
mortality of gray whales is expected or authorized, and any Level B
harassment takes of gray whales would most likely be in the form of
behavioral disturbance. Preliminary findings from necropsied gray
whales that are considered part of the ongoing UME have shown evidence
of emaciation, suggesting that impacts to feeding would be of most
concern. However, the project areas have not been identified as
important for feeding of gray whales. Additionally, the project areas
are not considered important for breeding gray whales. Therefore the
projects are unlikely to disrupt any
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critical behaviors (e.g., feeding, mating) or have any effect on the
reproduction or survival of gray whales, even in light of the ongoing
UME.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
these activities are not expected to adversely affect any of the
species or stocks through effects on annual rates of recruitment or
survival:
No mortality or serious injury is anticipated or proposed
to be authorized for either project;
Level A harassment is not anticipated or proposed to be
authorized for 9 of the 12 species. For the other three species, Level
A harassment would be in the form of a slight degree of PTS;
Level B harassment would be in the form of behavioral
disturbance, primarily resulting in avoidance of the project areas
around where impact or vibratory pile driving is occurring, and some
low-level TTS that may limit the detection of acoustic cues for
relatively brief amounts of time in relatively confined footprint of
the activities;
Nearby areas of similar habitat value within Puget Sound
are available for marine mammals that may temporarily vacate the
project areas during construction activities for both projects;
Effects on species that serve as prey for marine mammals
from the activities are expected to be short-term and, therefore, any
associated impacts on marine mammal feeding are not expected to result
in significant or long-term consequences for individuals, or to accrue
to adverse impacts on their populations from either project;
The number of anticipated takes by Level B harassment is
relatively low for all stocks for both projects;
The ensonifed areas from both projects are very small
relative to the overall habitat ranges of all species and stocks, and
will not adversely affect ESA-designated critical habitat, or cause
more than minor impacts in any BIAS or any other areas of known
biological importance;
The lack of anticipated significant or long-term negative
effects to marine mammal habitat from either project;
The efficacy of the mitigation measures in reducing the
effects of the specified activities on all species and stocks for both
projects; and
Monitoring reports from similar work in Puget Sound that
have documented little to no effect on individuals of the same species
that could be impacted by the specified activities from both projects.
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 proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
For all species and stocks other than killer whales from the West
Coast Transient stock, the proposed take is below one-third of the
stock abundance. The proposed take of transient killer whales, as a
proportion of the stock abundance is 34.4 percent, if all takes are
assumed to occur for unique individuals. In reality, it is unlikely
that all takes would occur to different individuals. The project area
represents a small portion of the stock's overall range (from Alaska to
California (Muto et al., 2019)) and based on sightings reports from the
Orca Network, it is reasonable to expect that the same individual
transient killer whales would be present within the project area on
multiple days during the proposed activities. Therefore, it is more
likely that there will be multiple takes of a smaller number of
individuals within the project area, such that the number of
individuals taken would be less than one third of the population.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals would be taken relative to the population
size of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species 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
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally whenever we propose to authorize take for
endangered or threatened species.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to WSDOT for conducting the Bainbridge Island Ferry
Terminal Overhead Loading Replacement Project and Eagle Harbor
Maintenance Facility Slip F Improvement Project in Bainbridge Island,
Washington during the August 2022 to February 2023 in-water work
season, provided the previously mentioned mitigation, monitoring, and
reporting requirements are incorporated. A draft of the proposed IHA
can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of proposed IHA for the proposed
Bainbridge Island Ferry Terminal Overhead Loading Replacement Project
and Eagle Harbor Maintenance Facility Slip F Improvement Project. We
also request comment on the potential renewal of this proposed IHA as
described in the paragraph below. Please include with your comments any
supporting data or literature citations to help inform
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decisions on the request for this IHA or a subsequent renewal IHA.
On a case-by-case basis, NMFS may issue a one-time, one-year
renewal IHA following notice to the public providing an additional 15
days for public comments when (1) up to another year of identical or
nearly identical activities as described in the Description of Proposed
Activities section of this notice is planned or (2) the activities as
described in the Description of Proposed Activities section of this
notice would not be completed by the time the IHA expires and a renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
A request for renewal is received no later than 60 days
prior to the needed renewal IHA effective date (recognizing that the
renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA).
The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the affected
species or stocks, and any other pertinent information, NMFS determines
that there are no more than minor changes in the activities, the
mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: August 4, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2022-17141 Filed 8-9-22; 8:45 am]
BILLING CODE 3510-22-P