[Federal Register Volume 89, Number 146 (Tuesday, July 30, 2024)]
[Notices]
[Pages 61064-61087]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-16753]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XE018]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Washington State Department of 
Transportation's Seattle Slip 3 Vehicle Transfer Span Project in 
Washington State

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from Washington State Department 
of Transportation (WSDOT) for authorization to take marine mammals 
incidental to Seattle Slip 3 Vehicle Transfer Span (VTS) Replacement 
Project in Seattle, Washington. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an incidental harassment authorization (IHA) to incidentally take 
marine mammals during the specified activities. NMFS is also requesting 
comments on a possible one-time, 1-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 August 
29, 2024.

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]. 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 below.
    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 https://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: Austin Demarest, Office of Protected 
Resources, NMFS, (301) 427-8401.

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 IHA 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 NAO 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 December 19, 2023, NMFS received a request from WSDOT for an IHA 
to take marine mammals incidental to Seattle Slip 3 VTS Replacement 
Project in Elliott Bay of the Puget Sound, Seattle, WA. Following NMFS' 
review of the application, WSDOT submitted revised versions on March 4, 
April 8, April 18, and April 29, 2024. A final revised monitoring plan 
was

[[Page 61065]]

submitted on May 14, 2024 and a final revised application was submitted 
on May 16, 2024. The application was deemed adequate and complete on 
May 20, 2024. WSDOT's request is for take of 12 species of marine 
mammals, by Level B harassment only. Neither WSDOT nor NMFS expect 
serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate.

Description of Proposed Activity and Anticipated Impacts

Overview

    WSDOT is proposing to replace the Seattle Slip 3 VTS at Colman Dock 
which is located in Elliott Bay of the Puget Sound in Seattle, 
Washington. The purpose of the construction project is to preserve the 
transportation function of an aging, seismically deficient transfer 
span. The existing VTS will be removed and replaced with a hydraulic 
transfer span consisting of steel drilled shafts and a new steel 
wingwall. In-water construction includes cutting sheet piles, 
installation and removal of steel piles with a vibratory hammer, and 
proofing steel piles with an impact hammer to drive them to the maximum 
depth and ensure load bearing capacity. In-water pile removal and 
driving with vibratory and impact hammers may result in incidental take 
by Level B harassment of 12 marine mammal species within Elliott Bay 
and the Central Puget Sound. The effective construction window for the 
project, which is expected to require a maximum of 19 days, is from 
August 1, 2024 through February 15, 2025. Replacement of the Seattle 
Slip 3 VTS will allow WSDOT to continue to provide safe and reliable 
transportation services throughout the Puget Sound and San Juan 
Islands.

Dates and Duration

    Construction for the Seattle Slip 3 VTS Replacement Project has an 
effective work window from August 1, 2024 through February 15, 2025 to 
avoid when ESA listed salmonids are most likely to be present. A 
maximum of 19 in-water construction days will occur, which includes a 
flexibility for adverse weather conditions and equipment malfunction. 
Operation hours for in-water construction will occur during daylight 
hours from sunrise to sunset but will be contingent upon weather 
conditions with good visibility. The IHA would be valid for 1 year from 
the date of issuance.

Specific Geographic Region

    Seattle Slip 3 VTS Replacement Project is part of the Seattle Ferry 
Terminal at Colman Dock and located along the Seattle waterfront in 
Elliott Bay (Figures 1 and 2). Elliott Bay is an urban embayment that 
is approximately 8 square miles (mi\2\) (21 square kilometers (km\2\)), 
central in the Puget Sound, Washington. The Seattle waterfront is 
highly urbanized with residential, business, and industrial areas 
including the Port of Seattle container loading facility, the Pioneer 
Square Historic District, and local parks.
BILLING CODE 3510-22-P

[[Page 61066]]

[GRAPHIC] [TIFF OMITTED] TN30JY24.003


[[Page 61067]]


[GRAPHIC] [TIFF OMITTED] TN30JY24.004

BILLING CODE 3510-22-C

Detailed Description of the Specified Activity

    Removal of the existing VTS and wingwall pile includes the 
extraction of 16 14-inch steel H-piles with a vibratory hammer and 
removal of a 30-inch concrete filled wingwall pile that would be cut at 
or below the mudline. Following removal of the VTS, 12 24-inch steel 
piles would be temporarily installed via a vibratory hammer and proofed 
with an impact hammer to confirm load bearing capacity for a temporary 
work platform. WSDOT would then permanently install 2 78-inch hollow 
steel drilled shafts via vibratory hammer. All the materials inside the 
78-inch steel shafts would be extracted with an auger or clamshell 
bucket and then dewatered for the hydraulic VTS. A 30-inch steel wing 
wall pile would then be installed with a vibratory hammer and then the 
12 24-inch temporary steel piles would be extracted via a vibratory 
hammer which concludes in-water construction. Table 1 provides a 
summary of the number of piles that would be removed and installed, the 
driving method, pile size, number of piles per day, time needed to 
drive each pile, and the maximum number of days needed to complete the 
Seattle Slip 3 VTS Replacement Project.
    Pile driving activities described above may result in Level B 
harassment of marine mammals in Elliott Bay and the central Puget Sound 
to the eastern shore of Bainbridge Island. Cutting the 30-inch wingwall 
pile and removal of the material from inside the 78-inch piles is 
expected to produce negligible in-water sound, which is unlikely to 
cause any incidental take of marine mammals. In-water construction 
would be a

[[Page 61068]]

maximum of 19 days from August 1, 2024 through February 15, 2025. The 
Seattle Slip 3 VTS Replacement Project would not use multiple hammers 
for installation or removal concurrently but vibratory and impact 
hammer could be used on the same day.
    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, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://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 1--Summary of Piles To Be Installed and Removed for the Seattle Slip 3 VTS Replacement Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                  Duration
           Pile size and type                        Method                 Install or remove       Number of    Piles per day    per pile     Duration
                                                                                                      piles       (24 hours)     (minutes)      (days)
--------------------------------------------------------------------------------------------------------------------------------------------------------
78-inch steel...........................  Vibratory..................  Install...................            2               1           60            2
30-inch steel...........................  Vibratory..................  Install...................            1               1           60            1
24-inch steel...........................  Vibratory..................  Install...................           12               3           30            4
24-inch steel...........................  Impact.....................  Install...................           12               3           30            4
                                         ---------------------------------------------------------------------------------------------------------------
    Subtotal............................  ...........................  ..........................  ...........  ..............  ...........           11
24-inch steel...........................  Vibratory..................  Remove....................           12               3           30            4
14-inch steel...........................  Vibratory..................  Remove....................           16               4           30            4
                                         ---------------------------------------------------------------------------------------------------------------
    Subtotal............................  ...........................  ..........................  ...........  ..............  ...........            8
                                         ---------------------------------------------------------------------------------------------------------------
        Total...........................  ...........................  ..........................  ...........  ..............  ...........           19
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 2 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 proposed 
to be authorized here, PBR and annual serious injury and mortality from 
anthropogenic sources are included here as gross indicators of the 
status of the species or stocks 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. Survey abundance (as compared to stock or species 
abundance) is the total number of individuals estimated within the 
survey area, which may or may not align completely with a stock's 
geographic range as defined in the SARs. For some species, this 
geographic area or surveys 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 2 are the most recent available at 
the time of publication (including from the draft 2023 SARs) and are 
available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                              Table 2--Species Likely Impacted by the Specified Activities
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                                                                                         ESA/ MMPA status;   Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray whale......................  Eschrichtius robustus..  Eastern N Pacific......  -, -, N             26,960 (0.05, 25,849,         801        131
                                                                                                             2016).
    Minke whale.....................  Balaenoptera             CA/OR/WA...............  -, -, N             915 (0.792, 509, 2018)        4.1       0.19
                                       acutorostrata.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale \5\................  Orcinus orca...........  West Coast Transient...  -, -, N             349 (N/A, 349, 2018)..        3.5        0.4
    Bottlenose dolphin..............  Tursiops truncatus.....  CA/OR/WA offshore......  -, -, N             3,477 (0.696, 2,048,        19.70     >=0.82
                                                                                                             2018).
    Long beaked common dolphin......  Delphinus capensis.....  CA.....................  -, -, N             83,379 (0.216, 69,636,        668     >=29.7
                                                                                                             2018).
    Pacific white-sided Dolphin.....  Lagenorhynchus           CA/OR/WA...............  -, -, N             34,999 (0.222, 29,090,        279          7
                                       obliquidens.                                                          2018).
Family Phocoenidae (porpoises):

[[Page 61069]]

 
    Dall's porpoise.................  Phocoenoides dalli.....  CA/OR/WA...............  -, -, N             16,498 (0.61, 10,286,          99     >=0.66
                                                                                                             2018).
    Harbor porpoise.................  Phocoena phocoena......  Washington Inland        -, -, N             11,233 (0.37, 8,308,           66      >=7.2
                                                                Waters.                                      2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    CA sea lion.....................  Zalophus californianus.  U.S....................  -, -, N             257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
    Steller sea lion \6\............  Eumetopias jubatus.....  Eastern................  -, -, N             36,308 (N/A, 36,308,        2,178       93.2
                                                                                                             2022).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Washington Northern      -, -, N             16,451 (0.07, 15,462,         928         40
                                                                Inland Waters.                               2019).
    Northern elephant seal \7\......  Mirounga angustirostris  CA Breeding............  -, -, N             187,386 (N/A, 85,369,       5,122       13.7
                                                                                                             2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ 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.
\3\ 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.
\4\ 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 M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ Nest is based upon count of individuals identified from photo-ID catalogs in analysis of a subset of data from 1958-2018.
\6\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the U.S.
  only.
\7\ There is uncertainty in available population estimates due to limited surveys, limited reproductive data, and uncertainty in stock relationships and
  harvest statistics.

    As indicated above, all 12 species in table 2 spatially and 
temporally co-occur with the activity to the degree that take is 
reasonably likely to occur. All species that could potentially occur in 
the proposed project areas are included in table 3 of the IHA 
application. While southern resident killer whales (SRKW), and humpback 
whales (HW) (Central America/Southern Mexico--California-Oregon-
Washington, Mainland Mexico--California-Oregon-Washington, and Hawaii 
stocks) have been documented in the area, the temporal and/or spatial 
occurrence of these species is such that take is not expected to occur, 
and they are not discussed further beyond the explanation provided 
here.
    Generally SRKWs are considered common in the Puget Sound (Olson et 
al., 2018). During the Seattle Multimodal Project 170 observations of 
SRKWs occurred over 377 construction days. Although SRKWs are 
relatively common in the construction area, WSDOT has expertise with 
monitoring for SRKWs and halting construction when they approach or 
enter established shutdown zones. For the Seattle Slip 3 VTS 
Replacement Project, WSDOT would establish shutdown zones for SRKWs at 
the estimated Level B harassment zones rounded up to the nearest 50 
meters. WSDOT would also monitor marine mammal occurrence and movement 
with the Orca Network and the Whale Report Alert System (WRAS) networks 
daily for this project. Considering SRKWs frequency of occurrence in 
the project area and WSDOTs experience mentioned above, take of SRKW is 
not expected.
    The occurrence of HWs in Puget Sound is considered common with the 
greatest density of sightings off the south end of Vancouver Island in 
the Strait of Juan de Fuca (Olsen et al., 2024). During the Seattle 
Multimodal Project 8 observations of HWs occurred over 377 construction 
days. Since the Seattle Slip 3 VTS Replacement Project is in the same 
area, HW occurrence in the construction area is expected to be rare. 
WSDOT would establish shutdown zones and monitor marine mammal 
occurrence and movement for HWs (identical to the measures described 
above for SRKWs). Therefore take of HWs in not expected. Details about 
mitigation measures, shutdown zones, and protected species observers 
(PSOs) can be found in the Proposed Mitigation and the Proposed 
Monitoring and Reporting sections below.
    Due to these mitigation measures and these species being highly 
conspicuous, incidental take of SRKWs or HWs is not expected for the 
duration of this project.

Gray Whale

    Generally, the Eastern North Pacific stock of gray whales feed in 
the Arctic in summer and fall months and then breed during winter and 
spring months off the coast of Mexico (Carretta et al. 2022, 
Calambokidis et al. 2024). During migration from Mexico to the Arctic, 
a subpopulation of the Eastern North Pacific stock of Gray whales, 
commonly referred to as the Pacific Coast Feeding Group (PCFG), stop 
and feed along the coasts of Oregon and Washington including the 
Northern Puget Sound (Calambokidis et al. 2024). A subgroup of the PCFG 
that feed in the Puget Sound, recently termed as ``Sounders'' gray 
whales, are the most abundant from February through May. The highest 
concentrations Sounders Gray Whales occurs on the Southern ends of 
Whidbey and Camano Islands in the North Puget Sound (Calambokidis et 
al. 2024). Although Sounders gray whale observations are the highest in 
the Northern Puget Sound but observations also occur in the Southern 
Puget Sound and Elliott Bay, which is in the proposed action area (Orca 
Network, 2021).
    There are Biologically Important Areas (BIAs) for migrating gray 
whales in the inland waters of the Northern Puget Sound from January 
through July and October through December and for feeding gray whales 
between February and June (Calambokidis et al., 2015; Calambokidis et 
al., 2024).
    The NMFS declared an unusual mortality event (UME) for gray whales 
on May 30, 2019 after elevated numbers of strandings occurred along the 
Pacific coast of North America, The UME started December 17, 2018 and 
was closed on November 9, 2023, with peak standings occurring from 
December 17, 2018 through December 31, 2020. The

[[Page 61070]]

UME included 690 gray whale standings, 347 in the United States, 316 in 
Mexico, and 27 in Canada. Necropsies were performed on a subset of the 
dead whales and malnutrition was common followed by evidence of killer 
whale predation, entanglement, vessel strikes, and biotoxins were found 
in some carcasses as in years without UMEs. NMFS concluded that the 
nutritional conditions of live gray whales was lower prior to and 
during the UME. Gray whale abundance declined and calf production 
decline following the UME but calf production has begun to rebound. 
Additional information about this UME can be found at https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-eastern-north-pacific-gray-whale-ume-closed.

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; 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. 
Although minke whales are considered rare within the Puget Sound, three 
minke whales were observed during the Seattle Multimodal Project during 
the 377 days of marine mammal monitoring from 2017-2021.

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., 2021; 
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 1995; Ford 2014). Transient killer whales have been 
observed in central Puget Sound in all months (Orca Network 2021). 
During WSDOTs Seattle Multimodal Project, 79 transient killer whales 
were observed throughout the 377 days of in water work from 2017 
through 2021 with a maximum of 20 individuals observed on a single day.

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). Although bottlenose dolphins are considered rare in 
Puget Sound, six were observed during construction of the Seattle 
Multimodal Project from 2017 through 2022 (WSDOT 2022).

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). Marine mammal monitors observed two long-beaked common 
dolphins during construction for the Washington State Ferries 
Multimodal Project at Colman Dock in Seattle from 2017-18 construction 
window (WSDOT 2022).

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

[[Page 61071]]

waters (Green et al., 1993). 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 construction for the Washington State Ferries Multimodal Project 
at Colman Dock in Seattle, only 2 Pacific white-sided dolphins were 
observed on one of the 377 days of construction from 2017 through 2021 
(WSDOT 2022).

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 
construction for the Washington State Ferries Multimodal Project at 
Colman Dock in Seattle, only 8 Dall's porpoises were observed, with a 
maximum of 5 individuals observed on a single day during the 377 
construction days from 2017 through 2021 (WSDOT 2022).

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 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 377 
total days of construction at the Washington State Ferries Multimodal 
Project at Colman Dock in Seattle from 2017 through 2021, 413 sightings 
of harbor porpoises were recorded in total, with a maximum of 40 
sightings 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).
    There are four commonly used haul-out sites near the construction 
site, with the closest haul-out site located 3 km (2 mi) southwest. 
During the Seattle Multimodal Project from 2017 through 2021, a total 
of 3,669 sightings of California sea lions were recorded over 377 days 
with a maximum of 29 observations 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 Elliott Bay and the Seattle waterfront area. Few 
Steller sea lions have been observed during monitoring of recent 
construction projects in the area; typically fewer than 5 total 
observations per year (e.g., Anchor QEA 2018, 2019). However, a total 
of 112 sightings of Steller sea lions were recorded over 377 days of 
monitoring from 2017 through 2021 at the Seattle Multimodal project 
with a maximum of 10 sightings on a single day.

Harbor Seal

    Harbor seals inhabit coastal and estuarine waters off Baja 
California, north along the western coasts of the continental United 
States, 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, 5 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.

[[Page 61072]]

    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 16,451 based on surveys 
conducted in 2019 (Carretta et al., 2023).
    There is only one routinely used harbor seal haulout near Elliott 
Bay and the Seattle waterfront at Blakely Rocks, approximately 10.6 km 
(6.6 mi) west of the project sites. The haulout, which is estimated at 
less 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 construction for the Washington State 
Ferries Multimodal Project at Colman Dock in Seattle, a maximum of 32 
harbor seals were observed on a single day from 2017 through 2021 for 
all 377 construction days.

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 all 377 construction days for the Washington State Ferries 
Multimodal Project at Colman Dock in Seattle from 2017 through 2021, 
only one 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.). 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 3.
    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 et al., 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

                  Table 3--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 (dolphins,      150 Hz to 160 kHz.
 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) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 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).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section provides a discussion of the ways in which components 
of the specified activity may impact marine mammals and their habitat. 
The Estimated Take of Marine Mammals 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 of Marine Mammals 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

[[Page 61073]]

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 are 
expected to result in only 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., 
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 project would 
include impact pile driving, vibratory pile driving, and vibratory pile 
removal. The sounds produced by these activities fall into one of two 
general sound types: impulsive and non-impulsive. Impulsive sounds 
(e.g., explosions, gunshots, 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; ANSI, 2005; NMFS, 2018). Non-impulsive sounds (e.g., 
aircraft, machinery operations such as drilling or dredging, vibratory 
pile driving, 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 rapid 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., Southall et al., 2007).
    Two types of pile hammers would be used on this project: impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels. 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 and produce 
significantly less sound than impact hammers. Peak sound pressure 
levels (SPLs) may be 180 dB or greater, but are generally 10 to 20 dB 
lower than SPLs generated during impact pile driving of the same-sized 
pile (Oestman et al., 2009). Rise time is slower, reducing the 
probability and severity of injury, and sound energy is distributed 
over a greater amount of time (Nedwell and Edwards, 2002; Carlson, et 
al., 2005).
    Potential or likely impacts on marine mammals from WSDOT's proposed 
construction include both non-acoustic and acoustic stressors. Non-
acoustic stressors include the physical presence of equipment, vessels, 
and personal. However, impacts from WSDOT's proposed construction is 
expected to primarily be acoustic in nature. Expected stressors from 
WSDOT's proposed activities are expected to be a result of heavy 
equipment operation for impact driving and vibratory driving and 
removal.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal is the primary means by which 
marine mammals may be harassed from WSDOT's specified activity. In 
general, animals exposed to natural or anthropogenic sound may 
experience physical and behavioral effects, ranging in magnitude from 
none to severe (Southall et al., 2007, 2021). Generally, exposure to 
pile driving noise has the potential to result in auditory threshold 
shifts (TS) 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 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 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. mom 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 (TSs) followed by behavioral effects 
and potential impacts on habitat. No physiological effects other than 
TTS are anticipated or proposed to be authorized, and therefore are not 
discussed further. Discussion of physical auditory effects (TSs), 
behavioral effects, and potential impacts on habitat are described 
below.
    NMFS defines a noise-induced 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

[[Page 61074]]

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)--A temporary, reversible 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). Based on data from cetacean TTS measurements 
(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 
(2015), 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). 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. 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).
    Pile installation for this project includes impact pile driving and 
vibratory pile driving and removal. Vibratory and impact pile driving 
would not occur simultaneously but both methods could be used on the 
same day. There would be pauses in the activities producing impulsive 
and non-impulsive sounds 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); 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., 2003; Southall et al., 
2007, 2021; Weilgart, 2007; Archer et al., 2010). Behavioral reactions 
can vary not only among individuals but also within exposures of an 
individual, depending on previous experience with a sound source, 
context, and numerous other factors (Ellison et al., 2012, Southall et 
al., 2021), 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. 
For a review of the studies involving marine mammal behavioral 
responses to sound, see Southall et al., 2007; Gomez et al., 2016; and 
Southall et al., 2021 reviews.
    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 estimates of the energetic 
requirements of the affected

[[Page 61075]]

individuals and the relationship between prey availability, foraging 
effort and success, and the life history stage of the animal.
    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. 
Elliott Bay and the Seattle area typically have elevated background 
sound levels due to active commercial shipping, fishing, and ferry 
operations as well as recreational use of the waterway.

Marine Mammal Habitat Effects

    WSDOTs 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 associated with this project are of 
short duration but may adversely affect acoustic habitat (see masking 
discussion above) and adversely affect marine mammal prey within the 
vicinity of the project (see discussion below). Elevated noise levels 
from impact and vibratory pile driving or removal would ensonify the 
project area where fish and marine mammals occur, which could affect 
foraging success.
    In-water pile driving and removal would also cause short term 
effects on water quality, which includes increase in turbidity. WSDOT 
would employ standard construction best management practices and comply 
with state water quality standards during all planned activities, thus 
reducing any impacts to water quality. Due to the nature and duration 
of proposed effects, combined with both measure described above, the 
impact from increased turbidity levels is expected to be discountable.
    Pile driving and removal may temporarily increase turbidity due to 
increases in suspended sediment. However, possible increases in 
turbidity would temporary, restricted to the localized construction 
area, and minimal. WSDOT must also comply with state water quality 
standards, which would limit the extent of increased turbidity to the 
immediate project area. Generally, changes in turbidity is restricted 
to a localized radius of 25-feet around the pile (Everitt et al., 
1980). Cetaceans and pinnipeds are not expected to be within a radius 
that would have localized increases in turbidity, but if they did 
occur, they would likely be transiting through the area and could avoid 
the affected area. Therefore, the effects of turbidity to on marine 
mammal habitat is expected to be discountable. Lastly, pile driving and 
removal would not obstruct the migration or movement of marine mammals.

In-Water Construction Effect on Potential Foraging Habitat

    The area likely impacted by the project is relatively small and 
provides marginal foraging habitat for marine mammals and fishes 
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 of similar or better quality in the nearby vicinity.

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

[[Page 61076]]

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., 
2016).
    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 Elliott Bay are routinely exposed to substantial levels of 
suspended 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 of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization through the IHA, which will inform NMFS' 
consideration of ``small numbers,'' the negligible impact 
determinations, and impacts on subsistence uses.
    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 be by Level B harassment only, in the form 
behavioral reactions and TTS for individual marine mammals resulting 
from exposure to noise from impact and vibratory pile driving and 
removal. Based on the nature of the activity and the anticipated 
effectiveness of the mitigation measures (i.e., shutdown zones at the 
Level A harassment area) discussed in detail below in the Proposed 
Mitigation section, Level A harassment is neither anticipated nor 
proposed to be authorized.
    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. For in-air sounds, NMFS predicts that harbor 
seals exposed above received levels of 90 dB re 20 [mu]Pa (rms) will be 
behaviorally harassed, and other pinnipeds will be harassed when 
exposed above 100 dB re 20 [mu]Pa (rms). Generally speaking, Level B 
harassment take estimates based on these behavioral

[[Page 61077]]

harassment thresholds are expected to include any likely takes by TTS 
as, in most cases, the likelihood of TTS occurs at distances from the 
source less than those at which behavioral harassment is likely. TTS of 
a sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    WSDOTs proposed activity includes the use of continuous (vibratory 
hammer) and impulsive (impact hammer) sources, and therefore the RMS 
SPL thresholds of 120 and 160 dB re 1 [mu]Pa, respectively, 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). WSDOTs 
proposed activity includes 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: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 4--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.
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, peak sound pressure is defined by ANSI 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 area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected by sound generated from the 
impact and vibratory pile driving components of this project.
    In order to calculate distances to the Level A harassment and Level 
B harassment thresholds for the methods and piles used in the proposed 
project, NMFS used acoustic monitoring data from previous pile driving 
at WSDOTs Bainbridge Island Ferry Terminal Project (vibratory removal 
of 12-inch H-piles), Port Townsend Ferry Terminal Project (vibratory 
installation and/or removal of 24 and 30-inch steel piles), Phase 2 of 
Colman Dock construction for the Seattle Multimodal Project (impact 
installation of 24-inch steel piles), and the Ebey Slough Bridge 
Replacement Project (Vibratory installation of 72-inch steel piles). 
Each of the projects listed above occurred within the Puget Sound and 
provided the most suitable source levels due to similar physical 
habitat characteristics, pile sizes, and pile driving or removal 
methods (Table 5).
    Source levels from the Bainbridge Terminal Ferry Project and the 
Ebey Slough Bridge Replacement Project were used as proxies for the 
vibratory installation of 78-inch steel pipe piles and the vibratory 
removal of 14-inch steel H-piles for the proposed project because 
source levels for identical pile sizes were unavailable. Results from 
the vibratory installation of 72-inch piles at the Ebey Slough Bridge 
Replacement Project showed that the unweighted RMS SPL source levels 
was 170 dB re 1 [micro]Pa at 15 m, therefore it was assumed that source 
levels for 78-inch piles would be 174 dB re 1 [micro]Pa at 10 m. The 
source levels for 14-inch H-piles was assumed to be equivalent to the 
vibratory removal of 12-inch H-piles at the Bainbridge Island Ferry 
Terminal where the unweighted RMS SPL source level was 153 dB re 1 
[micro]Pa at 10 m (WSDOT 2023). Bubble curtains would be employed for 
impact installation of 24-inch steel piles but zero dB of effective 
attenuation is assumed because a bubble curtain was used at Phase 2 of 
Colman Dock construction for the Seattle Multimodal Project, thus 
source levels would be the same.

   Table 5--Seattle Slip 3 Vehicle Transfer Span Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
                                                                  Source Level at 10 m
       Pile type and size (in)                  Method            (dB re 1 [micro]PA)           Reference
----------------------------------------------------------------------------------------------------------------
14-inch steel H-piles................  Vibratory Removal......  153 dB rms.............  WSDOT (2023).

[[Page 61078]]

 
24-inch steel pipe piles.............  Vibratory installation   174 dB rms.............  Huey (2010).
                                        and removal.
24-inch steel pipe piles.............  Impact installation....  166 SEL, 176 dB rms,     Greenbusch Group
                                                                 194 dB peak.             (2019).
30-inch steel sheet piles............  Vibratory installation.  174 dB rms.............  Huey (2010).
78-inch steel pipe piles.............  Vibratory installation.  174 dB rms.............  WSDOT (2011).
----------------------------------------------------------------------------------------------------------------

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 the WSDOTs proposed activities in the absence of 
specific modelling. The estimated Level B harassment zones for the 
WSDOTs proposed activities are shown in Tables 6 and 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 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. Inputs used in the optional User 
Spreadsheet tool (e.g., number of piles per day, during and/or strikes 
per pile) are presented in table 1, and the resulting estimated 
isopleths and ensonified areas are reported in tables 6 and 7.

                                                      Table 6--Level A and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Level A harassment zone (m)
                                                                               -------------------------------------------------------------   Level A
              Pile size and type                     Pile driving method             LF           MF           HF                             harassment
                                                                                 cetaceans    cetaceans    cetaceans    Phocids    Otarids     zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch steel................................  Vibratory removal..............          3.2          0.3          4.7        1.9        0.1        1,585
24-inch steel................................  Vibratory installation and              65.8          5.8         97.3       40.0        2.8   \a\ 15,410
                                                removal.
24-inch steel................................  Impact installation............         75.9          2.7         90.4       40.6        3.0          736
30-inch steel................................  Vibratory installation.........         50.2          4.5         74.3       30.5        2.1   \a\ 15,410
78-in steel..................................  Vibratory installation.........         50.2          4.5         74.3       30.5        2.1   \a\ 15,410
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Land is reached at a maximum of 15,410 km/9.6 miles.


                                                      Table 7--Level A and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Level A harassment zone (m)
                                                                               -------------------------------------------------------------   Level B
              Pile size and type                     Pile driving method             LF           MF           HF                             harassment
                                                                                 cetaceans    cetaceans    cetaceans    Phocids    Otarids     zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch steel................................  Vibratory removal..............          8.0         0.07         17.4        2.8      0.007    3,247,392
24-inch steel................................  Vibratory installation and           4,524.5          5.7        6,418    1,294.6       7.07   75,844,286
                                                removal.
24-inch steel................................  Impact installation............         75.9          2.7         90.4       40.6        3.0      861,188
30-inch steel................................  Vibratory installation.........      1,979.2         15.9        4,336      730.6        3.5   75,844,286
78-inch steel................................  Vibratory Installation.........      1,979.2         15.9        4,336      730.6        3.5   75,844,286
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 61079]]

Marine Mammal Occurrence and Take Estimation

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform proposed take incidental to WSDOTs pile driving activities 
for the Seattle Slip 3 VTS Replacement Project. Throughout this section 
the pile installation or removal will be referred to as ``pile 
driving'' unless specified otherwise. From 2017 through 2021 WSDOT 
monitored for marine mammals in Elliott Bay for the Seattle Multimodal 
Project. During this time, marine mammal monitoring occurred for 377 
days. Since the Seattle Multimodal Project occurred in Elliott Bay, 
WSDOT considered this marine mammal monitoring data to be the most 
comprehensive and relevant for estimating take for the Seattle Slip 3 
VTS Replacement Project. Therefore, this data compiled all of these 
monitoring results and calculated total sightings, average sightings 
per day, and maximum sightings per day for all species of marine 
mammals that were observed (table 8). WSDOT used their best 
professional judgement and used this data to estimate take by 
multiplying maximum sighting per day by 19, which is the maximum number 
of in-water working days WSDOT estimates it would take to complete the 
project in a total worst case scenario.
    NMFS has carefully evaluated these methods and concludes that it is 
an accurate and appropriate method for estimating take for WSDOTs 
activities for this project.

                        Table 8--Marine Mammals Sighted at the Seattle Multimodal Project
----------------------------------------------------------------------------------------------------------------
                                                                      Average         Maximum
                                                       Total        individuals     individuals
                     Species                        individuals     sighted/day   sighted in one- Take requested
                                                    sighted \a\   (377 days) \a\      day \a\
----------------------------------------------------------------------------------------------------------------
Harbor seal.....................................           2,271             6.0              32             Yes
Northern elephant seal..........................               1           0.003               1             Yes
California sea lion.............................           3,669             9.7              29             Yes
Steller sea ion.................................             112             0.3              10             Yes
Unidentified pinniped...........................             121             N/A             N/A             N/A
Killer whale Southern resident..................             170             0.5              26              No
Killer whale transient..........................              79             0.2              20             Yes
Gray whale......................................               5            0.01               2             Yes
Humpback whale..................................               8            0.02               1              No
Minke whale.....................................               3           0.008               1             Yes
Unidentified large whale........................               2             N/A               1             N/A
Unidentified small whale........................              10             N/A             N/A             N/A
Harbor porpoise.................................             655             1.7              72             Yes
Dall's porpoise.................................               8            0.02               5             Yes
Common bottlenose dolphin.......................               6            0.02               2             Yes
Pacific white-sided dolphin.....................               2           0.005               2             Yes
Long-beaked common dolphin......................               0             N/A               0             Yes
Unidentified dolphin/porpoise...................              46             N/A               6             N/A
----------------------------------------------------------------------------------------------------------------
\a\ WSDOT 2022.

    Gray Whale--Although gray whales are common on the southern ends of 
Whidbey and Camano Islands in the Puget Sound February through May, 
they are rarely sighted in the proposed construction area (Calambokidis 
et al. 2024). During the Seattle multimodal project only 5 gray whales 
were detected over 377 days of monitoring with a maximum of two 
individuals observed on a single day (WSDOT 2022). WSDOT estimated that 
up to 2 gray whales could be taken per day for the 19 days of 
construction, for a total of 38 takes by Level B harassment.
    Since Seattle Slip 3 VTS Replacement Project construction would 
occur from August through mid-February, gray whales occurrence is 
expected to be relatively low. In this context, and given that gray 
whales are highly conspicuous, we have a high degree of confidence that 
WSDOT can successfully implement shutdowns as necessary to avoid any 
potential Level A harassment of gray whales. WSDOT must also monitor 
the Orca Network and the Whale Report Alert System (WRAS) daily in 
order to maintain awareness of regional whale occurrence and movements 
(see Proposed Mitigation and Proposed Monitoring and Reporting sections 
below). Therefore, take of gray whales by Level A harassment is not 
anticipated or for authorization.
    Minke Whale--Minke whales are uncommon during fall and winter 
months in the Puget Sound but are rarely sighted in the proposed 
construction area (Calambokidis and Baird 1994). During the Seattle 
Multimodal Project only three minke whale detections occurred over 377 
days of monitoring with a maximum of one detection on a single day 
(WSDOT 2022). WSDOT estimated that up to one minke whale could be taken 
per day for the 19 days of construction, for a total of 19 takes by 
Level B harassment.
    Since the Seattle Slip 3 VTS Replacement Project construction would 
occur from August through mid-February, minke whale occurrence is 
expected to be relatively low. In these circumstances, and given that 
minke whales are highly conspicuous, we have a high degree of 
confidence that WSDOT can successfully implement shutdowns as necessary 
to avoid any potential Level A harassment of minke whales. WSDOT must 
also monitor the Orca Network and the Whale Report Alert System (WRAS) 
daily in order to maintain awareness of regional whale occurrence and 
movements (see Proposed Mitigation and Proposed Monitoring and 
Reporting sections below). Therefore, take of minke whales by Level A 
harassment is not anticipated or for authorization.
    Transient Killer Whale--Transient killer whales are common in in 
the Puget Sound in all months and a total of 79 transient killer whale 
detections occurred over 377 days of monitoring for the Seattle 
Multimodal Project with a maximum of 20 detections in a single day 
(Orca Network 2021, WSDOT 2022). WSDOT estimated that up to 20 
incidents of take for transient killer whales could occur per day for 
19 days of construction, for a total of 380 takes by Level B 
Harassment. Transient killer

[[Page 61080]]

whales are common in the Puget Sound and are highly conspicuous.
    The largest Level A harassment zone for mid-frequency cetaceans for 
all construction for the Seattle Slip 3 VTS Replacement Project is less 
than 6 m. It is highly unlikely that any cetacean would enter within 6 
m of active pile driving, and no take by Level A harassment for any 
mid-frequency cetacean is expected to occur. WSDOT must also monitor 
the Orca Network and the Whale Report Alert System (WRAS) daily in 
order to maintain awareness of regional whale occurrence and movements 
(see Proposed Mitigation and Proposed Monitoring and Reporting sections 
below). Therefore, take of transient killer whales by Level A 
harassment is not anticipated or for authorization.
    Bottlenose Dolphin--Bottlenose dolphins are considered to be rare 
in the Puget Sound but they were detected by the Cascadia Research 
Collective and reported via the Orca Network in 2017 (Cascadia Research 
Collective, 2017). They were also detected on 6 occasions with a 
maximum of 2 detections on a single day during the Seattle Multimodal 
Project (WSDOT 2022). WSDOT estimated that up to two bottlenose 
dolphins could be taken per day for the 19 days of construction, for a 
total of 38 takes by Level B harassment.
    The largest Level A harassment zone for mid-frequency cetaceans for 
all construction of the Seattle Slip 3 VTS Replacement Project is less 
than 6 m. It is highly unlikely that any cetacean would enter within 6 
m of active pile driving, and no take by Level A harassment for any 
mid-frequency cetacean is expected to occur. WSDOT must also monitor 
the Orca Network and the Whale Report Alert System (WRAS) daily in 
order to maintain awareness of regional whale occurrence and movements 
(see Proposed Mitigation and Proposed Monitoring and Reporting sections 
below). Therefore, take of bottlenose dolphins by Level A harassment is 
not anticipated or for authorization.
    Long-Beaked Common Dolphin--No confirmed detections of long-beaked 
common dolphins occurred during the Seattle Multimodal Project but 6 
unidentified delphinids were observed (WSDOT 2022). WSDOT assumed that 
up to two of these unidentified delphinids could have been long-beaked 
common dolphins. Therefore, WSDOT estimated that up to two long-beaked 
common dolphins could be taken per day for the19 days of construction, 
for a total of 38 takes by Level B harassment.
    The largest Level A harassment zone for mid-frequency cetaceans for 
all construction of the Seattle Slip 3 VTS Replacement Project is less 
than 6 m. It is highly unlikely that any cetacean would enter within 6 
m of active pile driving, and no take by Level A harassment for any 
mid-frequency cetacean is expected to occur. WSDOT must also monitor 
the Orca Network and the Whale Report Alert System (WRAS) daily in 
order to maintain awareness of regional whale occurrence and movements 
(see Proposed Mitigation and Proposed Monitoring and Reporting sections 
below). Therefore, take of long-beaked common dolphins by Level A 
harassment is not anticipated or for authorization.
    Pacific White-Sided Dolphin--Pacific white-sided dolphins are rare 
in the Puget Sound but have been observed in San Juan Channel (Orca 
Network 2012). Two Pacific white sided dolphins were also observed 
during the Seattle Multimodal Project (WSDOT 2022). WSDOT estimated 
that up to two Pacific white-sided dolphins could be taken per day for 
the 19 days of construction, for a total of 38 takes by Level B 
harassment.
    The largest Level A harassment zone for mid-frequency cetaceans for 
all construction of the Seattle Slip 3 VTS Replacement Project is less 
than 6 m. It is highly unlikely that any cetacean would enter within 6 
m of active pile driving, and no take by Level A harassment for any 
mid-frequency cetacean is expected to occur. WSDOT must also monitor 
the Orca Network and the Whale Report Alert System (WRAS) daily in 
order to maintain awareness of regional whale occurrence and movements 
(see Proposed Mitigation and Proposed Monitoring and Reporting sections 
below). Therefore, take of Pacific white-sided dolphins by Level A 
harassment is not anticipated or for authorization.
    Dall's Porpoise--Dall's porpoises are considered rare within the 
project area. WSDOT recorded only 8 detections over 377 days of 
monitoring during the Seattle Multimodal Project (WSDOT 2022). WSDOT 
estimated that up to 5 Dall's porpoises could be taken per day for the 
19 days of construction, for a total of 95 takes by Level B harassment.
    The largest Level A harassment zone for high-frequency cetaceans 
for all construction of the Seattle Slip 3 VTS Replacement Project is 
less than 100 m. Due to the relatively short duration of construction 
for the Seattle Slip 3 VTS Replacement Project and infrequent 
detections of Dall's porpoises, WSDOT estimated that no Dall's 
porpoises would be likely to enter the Level A harassment zone. Take by 
Level A harassment of Dall's Porpoises is not anticipated or proposed 
to be authorized.
    Harbor Porpoise--From 2017 through 2022, WSDOT recorded 655 
detections of harbor porpoises with a maximum of 72 detections on a 
single day (WSDOT 2022). WSDOT estimated that up to 72 instances of 
take for harbor porpoises could occur per day for the 19 days of 
construction, for a total of 1,368 takes by Level B harassment.
    The largest Level A harassment zone for high-frequency cetaceans is 
under 100 m. Although harbor porpoises are relatively common in the 
Puget Sound, we assume that WSDOT would be able to cease construction 
if harbor porpoises entered the Level A harassment zone before 
sufficient duration of exposure for PTS to occur. Take by Level A 
harassment is not anticipated or proposed to be authorized.
    California Sea Lion--California sea lions are relatively common 
throughout the Puget Sound. During the Seattle Multimodal Project a 
maximum of 29 sea lions were detected on a single day with a total of 
3,669 sightings over the 377 days of monitoring (WSDOT 2022). WSDOT 
estimated that 32 California sea lions would enter the Level B 
harassment zone for each of the 19 days of construction, for a total of 
551 takes by Level B harassment.
    The largest Level A harassment zone for Otariids for all 
construction of the Seattle Slip 3 VTS Replacement Project is less than 
3 m. It is highly unlikely that any Otariids would enter within 3 m of 
active pile driving, and no take by Level A harassment for any mid-
frequency cetacean is expected to occur. Therefore, take of California 
sea lions by Level A harassment is not anticipated or for 
authorization.
    Steller Sea Lion--Monitoring during the Seattle Multimodal Project 
recorded 112 detections of Steller sea lions over 377 days of 
monitoring, which is less than one detection per day. However, a 
maximum of 10 detections were recorded in a single day. Therefore, 
WSDOT estimated that 10 stellar sea lions would enter the Level B 
harassment zone each day for the 19 days of construction of the 
project, for a total of 190 takes by Level B harassment.
    The largest Level A harassment zone for Otariids for all 
construction of the Seattle Slip 3 VTS Replacement Project is less than 
3 m. It is highly unlikely that any Otariids would enter within 3 m of 
active pile driving, and no take by Level A harassment for any mid-
frequency cetacean is expected to occur. Therefore, take of steller sea 
lions by

[[Page 61081]]

Level A harassment is not anticipated or for authorization.
    Harbor Seal--Harbor seals are common in the project area. During 
the Seattle Multimodal Project WSDOT recorded an average of 6 harbor 
seal detections per day and a maximum of 32 in a single day (WSDOT 
2022). WSDOT estimated that a maximum of 32 harbor seals will enter the 
Level B harassment zones for each of the 19 days of construction, for a 
total of 608 takes by Level B harassment.
    The largest Level A harassment zone for high-frequency phocids is 
under 41 m. Although harbor seals are relatively common in the Puget 
Sound, we assume that WSDOT would be able to cease construction if 
harbor seals entered the Level A harassment zone before sufficient 
duration of exposure for PTS to occur. Take by Level A harassment is 
not anticipated or proposed to be authorized.
    Northern Elephant Seal--Although northern elephant seals are rare 
in the Puget Sound, 1 individual was detected during the Seattle 
Multimodal Project. Since northern elephant seals are rare in the 
proposed construction area, WSDOT estimated that a maximum of 1 
elephant seal would enter the Level B harassment zone per day for each 
of the 19 days of construction. A total of 19 takes by Level B 
harassment is estimated for northern elephant seals for construction 
associated with the Seattle Slip 3 VTS Replacement Project.
    Similar to harbor seals, the largest harassment zone is less than 
41 m for all construction activities. Given the anticipated rarity of 
occurrence for elephant seals, WSDOT does not expect northern elephant 
seals to enter Level A harassment zones without being detected prior to 
shutdown. Construction would cease if a northern elephant seal was 
observed entering Level A harassment zone. Therefore, no take by Level 
A harassment of northern elephant seals is anticipated or proposed to 
be authorized.

       Table 9--Estimated Take of Marine Mammal by Level B Harassment for 19 Days of In-Water Construction
----------------------------------------------------------------------------------------------------------------
                                                                              Total takes by
                        Species                          Maximum sightings/      Level B        Percent of stock
                                                              day \a\           harassment
----------------------------------------------------------------------------------------------------------------
                                                     Phocids
----------------------------------------------------------------------------------------------------------------
Harbor seal............................................                 32                608               5.51
Northern elephant seal.................................                  1                 19               0.02
----------------------------------------------------------------------------------------------------------------
                                                    Otariids
----------------------------------------------------------------------------------------------------------------
California sea lion....................................                 29                551               0.24
Steller sea lion.......................................                 10                190               0.23
----------------------------------------------------------------------------------------------------------------
                                                    Cetaceans
----------------------------------------------------------------------------------------------------------------
Killer whale transient.................................                 20                380                110
Gray whale.............................................                  2                 38               0.15
Minke whale............................................                  1                 19                3.7
Harbor porpoise........................................                 72              1,368               16.5
Dall's porpoise........................................                  5                 95               0.37
Common bottlenose dolphin..............................                  2                 38                3.0
Pacific white-sided dolphin............................                  2                 38               0.13
Long-beaked common dolphin.............................                  5                 38               0.05
----------------------------------------------------------------------------------------------------------------
\a\ WSDOT 2022.

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

    Prior to the start of any in-water construction, WSDOT would 
establish shutdown zones for all planned activities. Shutdown zones are 
pre-defined areas within which construction would be halted upon 
sightings of a marine mammal or in anticipation of a marine mammal 
entering the established shutdown zones. Pile-driving would not re-
commence until all marine mammals are assumed to have cleared these 
established shutdown zones.
    WSDOT proposed to establish shutdown zones for SRKWs and HWs at the 
Level B harassment zone for the vibratory removal of 14-in piles at 
1,600

[[Page 61082]]

m and at 750 m for impact driving 24-in piles (Table 6 and Table 10). 
These shutdown zones are the Level B harassment zone rounded up to the 
nearest 50 m for each pile size and driving method. Proposed shutdown 
zones for the remaining pile-driving for SRKWs and HWs would be 
established at 15,410 m, which is equivalent to the maximum Level B 
harassment area before it reaches land.
    The largest Level A harassment zone for the vibratory removal of 
14-in piles is 3.2 m for all cetaceans and pinnipeds. However, WSDOT 
proposed conservatively to implement a shutdown zone at 50 m for 
removal of 14-in piles. The proposed shutdown zones for the remaining 
pile-driving activities would be established at 100 m for all hearing 
groups of cetaceans (except SRKWs and HWs, as discussed above) and 50 m 
for all pinnipeds. The largest Level A harassment zone amongst all 
hearing groups of cetaceans is would be 97.3 m for the remaining pile-
driving (Table 6). The largest Level A harassment zone amongst 
pinnipeds would be 40.6 m for the remaining pile driving (Table 6). 
With WSDOTs proposed shutdown zones, all incidental take would be 
prevented for SRKWs and HWs and only take by Level B harassment would 
occur for the remaining species of cetaceans and pinnipeds.
    WSDOT would also establish shutdown zones for all other species of 
marine mammals for which take has not been authorized or for which 
incidental take has been authorized but the number of authorized takes 
has already been met. Those zones would be equivalent to Level B 
harassment zones provided for each activity in Table 6.
    In addition to the shutdown zones mentioned above, WSDOT proposes 
to implement shutdown measures for SRKWs and HWs. If SRKWs or HWs are 
observed within or approaching established shutdown zones (see table 
10), WSDOT would shut down pile driving equipment to avoid take of 
these species. If a killer whale approaches a Level B harassment zone, 
and it is unknown if it is a SRKW or a Transient killer whale, WSDOT 
would assume it is a SRKW and implement shutdown measures. Pile driving 
would only resume if the killer whale could be confirmed as a Transient 
killer whale.

                         Table 10--Shutdown Zones for All Pile-Driving Activities for the Seattle Slip 3 VTS Replacement Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    Shutdown zones (m)
                                                                              -------------------------------------------------------------  SRKW and HW
             Pile size and type                     Pile driving method             LF           MF           HF                              shutdown
                                                                                cetaceans    cetaceans    cetaceans    Phocids    Otarids     zones (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-in steel.................................  Vibratory removal..............           50           50           50         50         50         1,600
24-in steel.................................  Vibratory installation and               100          100          100         50         50      * 15,410
                                               removal.
24-in steel.................................  Impact installation............          100          100          100         50         50           750
30-in steel.................................  Vibratory installation.........          100          100          100         50         50      * 15,410
78-in steel.................................  Vibratory Installation.........          100          100          100         50         50      * 15,410
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 15,410 m is the maximum distance sound can travel before reaching land.

Protected Species Observers

    The monitoring locations for all protected species observers (PSOs) 
during all pile driving activities (described in the Proposed 
Monitoring and Reporting Section) would ensure that the entirety of all 
shutdown zones are visible. If environmental conditions deteriorate 
such that the entirety of shutdown zones would not be visible (e.g., 
fog, heavy rain, Beaufort sea state, etc.), all pile driving would be 
delayed until PSOs are confident that marine mammals in the shutdown 
zones could be detected.

Monitoring for Level A and Level B Harassment

    All of the harassment zones would be monitored by PSOs to the 
extent practicable. Established monitoring zones would allow PSOs to 
observe marine mammals and define clear monitoring protocols for areas 
adjacent to shutdown zones. The monitoring zones and protocols would 
enable PSOs to be aware of and communicate the presence of marine 
mammals in project areas and outside of project areas to prepare for 
potential cessation of pile driving activities should a marine mammal 
enter a shutdown zone.

Pre-Activity Monitoring

    Prior to the start of daily in-water construction activities, or 
whenever a break in pile driving of 30 minutes or longer occurs, PSOs 
would observe shutdown and monitoring zones for a 30 minute period. The 
shutdown zone would be considered cleared when a marine mammal has not 
been observed within the zone for that 30-minute period. If pile 
driving is delayed or halted due to the presence of a marine mammal, 
the activities 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 and authorized take has not been 
met, activities may begin. 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).

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- 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

[[Page 61083]]

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 applicant's proposed measures, 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 activity; 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:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
     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 must be approved by NMFS prior to beginning any 
activities subject to this IHA.
    PSOs should 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 all pile driving activities, a minimum of 3 PSO will monitor 
shutdown zones during pile driving activities. A total of 3 PSOs will 
monitor the area for the vibratory removal 14-in steel H-piles, 2 PSOs 
will monitor from the construction site and the other PSO will monitor 
from Pier 69/70. For the vibratory installation and removal of 24, 30, 
and 78-in steel pipe piles 8 PSOs will monitor shutdown zones. PSOs as 
described above, 1 PSO will be stationed on each of the Seattle-
Bainbridge Island Ferries (2 PSOs in total on ferries), 1 PSO stationed 
at Alki Beach Pier on the south end of Elliott Bay, 1 PSO stationed at 
Magnolia Viewpoint on the north end of Elliott Bay, 1 PSO station at 
Rolling Bay on Bainbridge Island, and another PSO stationed at Rockaway 
Beach on Bainbridge Island. During impact pile driving 24-in steel pipe 
piles, 2 PSOs will be stationed at the construction site and an 
additional PSO will be stationed at pier 62 at the north end of the 
SRKW and HW shutdown zones (Figure 3).
    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.
BILLING CODE 3510-22-P

[[Page 61084]]

[GRAPHIC] [TIFF OMITTED] TN30JY24.005

BILLING CODE 3510-22-C

Coordination With Marine Mammal Research Networks

    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. Daily sightings information will be checked several 
times a day. The Orca 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 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.
    WSDOT also participates in the Whale Report Alert System (WRAS/
WhaleReport Alert System--Ocean Wise). In October 2018, the Ocean Wise 
Sightings Network (formerly the B.C. Cetacean Sightings Network) 
launched an alert system that broadcasts details of whale presence to 
large commercial vessels. Information on whale presence is obtained 
from real-time observations reported to the Ocean Wise Sightings 
Network via the WhaleReport app. The alerts inform shipmasters and 
pilots of cetacean occurrence in their vicinity. This awareness better 
enables vessels to undertake adaptive mitigation measures, such as 
slowing down or altering course in the presence of cetaceans, to reduce 
the risk of collision and disturbance.
    All WSDOT ferry vessel crews have been trained in the use of WRAS, 
and input new sightings of cetaceans so data would be available to 
other vessels and to PSOs on the project. The lead PSO will check the 
WRAS sightings regularly during the day to be aware of cetaceans 
approaching the shutdown zones.
    With this level of coordination in the region of activity, WSDOT 
would be able to get additional real-time information on the presence 
or absence of cetaceans prior to start of in-water construction each 
day.

[[Page 61085]]

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 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 and removal activities associated with this project 
have the potential to disturb or displace marine mammals. The 
activities for this project may result in incidental take, in the form 
of Level B harassment, from underwater sound generated from pile 
driving or removal. Potential takes could occur if marine mammals are 
present in the ensonified zone when pile driving activities are 
underway.
    The takes from Level B harassment would be due to potential 
behavioral disturbance and TTS. 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 discussion of our analysis applies to all 
the species listed in Table 2, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be 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

[[Page 61086]]

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.
    No take by Level A harassment is anticipated or proposed to be 
authorized incidental to the Seattle Slip 3 VTS Replacement Project. 
However, take by Level B harassment is expected and proposed to be 
authorized for 12 marine mammal species. Effects on individuals that 
are taken by Level B harassment, on the basis of reports in the 
literature as well as monitoring from other similar activities, will 
likely be limited to reactions such as area avoidance, increased 
swimming speeds, increased surfacing time, or decreased foraging (if 
such activity were occurring) (e.g., Thorson and Reyff 2006 and NMFS 
2018). Individual marine mammals would most likely move away from sound 
sources and temporarily avoid the ensonified area while pile driving is 
occurring. If the sound produced from the construction activities is 
sufficiently disturbing, marine mammals are likely to simply avoid the 
area while activities are occurring, particularly as the project is 
located on a busy waterfront with high amounts of vessel traffic. 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.
    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 (Elliott Bay 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 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. The Seattle waterfront is a busy area and monitoring 
reports from previous in water pile driving activities indicate that 
marine mammals remain in Elliott Bay and the central Puget Sound 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

    The Puget Sound is part of a BIA for gray whales as they migrate 
between the Arctic and Mexico (Calambokidis et al., 2024). Although the 
proposed project area is located within the Puget Sound, the gray whale 
BIA does not overlap with the ensonified zones and gray whales 
typically remain further north around Whidbey and Camano Islands 
(Calambokidis et al., 2018). Gray whales are also rarely seen in the 
project area. This suggests that impacts from the project would have 
minimal to no impact on the migration of gray whales in the BIA, and 
would therefore not affect reproduction or survival.
    There was a UME for gray whales from 2018 through 2023 (see the 
Description of Marine Mammals in the Area of Specified Activities 
section of this notice). However, we do not expect takes proposed to be 
authorized for this project to have any additional affects to 
reproduction or survival. As mentioned previously, no take by Level A 
harassment, serious injury or mortality is expected. Takes proposed to 
be authorize by Level B harassment of gray whales would primarily be in 
the form of behavioral disturbance. The results from necropsies showed 
evidence that gray whale nutritional condition was poor during the UME. 
The area that would be temporarily impacted from construction does not 
overlap with the gray whale feeding BIA in the northern Puget Sound. 
Therefore, the construction associated with the Seattle Slip 3 VTS 
Replacement Project is unlikely to disrupt any critical behaviors 
(e.g., feeding) or have any effect on reproduction or survival of gray 
whales.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect any of the species 
or stocks through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Level A harassment is not anticipated or proposed to be 
authorized for all 12 marine mammal species;
     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 the project is 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;

[[Page 61087]]

     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat from the project;
     The efficacy of the mitigation measures in reducing the 
effects of the specified activities on all species and stocks for the 
project; 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 the project.
    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 previously, only take of small numbers of marine mammals 
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 greater than one-third, if all 
takes are assumed to occur for different individuals. The project area 
represents a small portion of the stock's range from Alaska to 
California (Muto et al., 2019). Sighting reports from the Orca Network 
support that it is reasonable to suspect that the same individual 
Transient Killer whales would be present within the ensonified project 
area during the relatively short duration (19 days) of proposed 
activities. Since the construction area represents a small portion of 
Transient killer whales range and construction would occur over a short 
period, it is more likely that there will be multiple takes of the same 
individuals during proposed activities.
    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 ESA 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 Seattle Slip 3 VTS Replacement 
Project at Colman Dock in Seattle, Washington, 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 
Seattle Slip 3 VTS Replacement 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 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 
Activity section of this notice is planned or (2) the activities as 
described in the Description of Proposed Activity 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); and
     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); 
and
    (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.

Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2024-16753 Filed 7-29-24; 8:45 am]
BILLING CODE 3510-22-P