Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Trident Seafoods Bunkhouse Dock Replacement Project, Kodiak, Alaska, 88874-88892 [2023-28336]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 246 (Tuesday, December 26, 2023)]
[Notices]
[Pages 88874-88892]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-28336]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD515]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Trident Seafoods Bunkhouse Dock 
Replacement Project, Kodiak, Alaska

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 Trident Seafoods Corporation 
(Trident) for authorization to take marine mammals incidental to pile 
driving and removal activities associated with the Bunkhouse Dock 
replacement project in Kodiak, Alaska. 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 January 
25, 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 above.
    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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. 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: Rachel Wachtendonk, 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 June 15, 2023, NMFS received a request from Trident for an IHA 
to take marine mammals incidental to vibratory

[[Page 88875]]

and impact pile driving to replace the Bunkhouse Dock at their facility 
in Kodiak, Alaska. Following NMFS' review of the application, Trident 
submitted a revised version on September 1, 2023. The application was 
deemed adequate and complete on October 26, 2023. Trident's request is 
for take of six species of marine mammals by Level B harassment only. 
Neither Trident nor NMFS expect serious injury or mortality to result 
from this activity and, therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    Trident proposes to remove and replace the Bunkhouse Dock on the 
shore of Near Island Channel in Kodiak, Alaska. The purpose of this 
project is to remove the degraded dock and replace it with a new 
structure to provide safe housing and waterfront infrastructure for 
seafood processing. The activity includes the removal of existing piles 
and the installation of both temporary and permanent piles of various 
sizes. Takes of marine mammals by Level B harassment would occur due to 
down-the-hole (DTH) drilling and vibratory pile driving and removal. 
This project would occur Kodiak, Alaska along the western shore of Near 
Island Channel within Township 27S. Construction activities are 
expected to occur over 8 weeks starting in March 2024.

Dates and Duration

    The proposed activities are expected to start in March 2024 and 
last 8 weeks. It is expected to take 94 hours over 55 non-consecutive 
days. All pile driving and removal would be completed during daylight 
hours.

Specific Geographic Region

    The proposed activities would take place at the Trident Seafoods 
facility along the City of Kodiak's downtown working waterfront. It is 
located on the western shore of Near Island Channel in Kodiak, Alaska 
within Township 27S. All construction would occur within the footprint 
of the existing Trident-owned Bunkhouse Dock. The timing of this work 
is planned to not interfere with the commercial fishing season.
[GRAPHIC] [TIFF OMITTED] TN26DE23.000

Detailed Description of the Specified Activity

    The Bunkhouse Dock replacement will include the removal of 100 14-
inch (in) (36 centimeter (cm)) diameter timber piles, 75 14-in (36-cm) 
steel H-piles, and 60 16-in (41 cm) diameter steel pipe piles. Once the 
existing piles are removed, 26 16-in (41 cm) diameter steel pipe piles 
and 52 24-in (61 cm) diameter steel pipe piles would be installed to 
support the new pier. The installation and removal of 52 temporary 24-
in (61 cm) diameter steel pipe piles would be completed to support 
permanent pile installation. All piles will be removed with the 
deadpull method with the vibratory hammer being used if the deadpull 
method is unsuccessful. Temporary and permanent piles will be initially 
installed with the vibratory hammer followed by the DTH drill to embed 
them to their final depth. The work would be completed within the 
footprint of the existing Bunkhouse Dock in Kodiak, Alaska.

[[Page 88876]]



                                              Table 1--Number and Type of Piles To Be Installed and Removed
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                                                                                                                          Permanent pipe  Permanent pipe
                                           Existing pipe    Existing H-    Existing pile  Temporary pile  Temporary pile       pile            pile
                                           pile removal    pile removal       removal      installation       removal      installation    installation
                                              (steel)         (steel)        (timber)         (steel)         (steel)         (steel)         (steel)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile Diameter size (in).................              16              14              14              24              24              16              24
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Quantity..........................              60              75             100              20              20              26              52
Max # of Piles per day..................              20              20              25               6               8               5               4
Vibratory time per pile (min)...........               2               2               2               2               2               2               2
Number of Days..........................               3               4               4               3               3               5              13
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                                                                 Down the Hole Drilling
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Total Quantity..........................             n/a             n/a             n/a              20             n/a              26              52
Piles per day...........................             n/a             n/a             n/a               6             n/a               6               4
Duration time per pile (min)............             n/a             n/a             n/a              30             n/a              45              60
Number of Days..........................             n/a             n/a             n/a               3             n/a               4              13
--------------------------------------------------------------------------------------------------------------------------------------------------------

    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 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. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. 2022 SARs. All values presented in table 2 are the most 
recent available at the time of publication and are available online 
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                   Table 2--Marine Mammal Species \4\ Likely To Occur Near the Project Area That May Be Taken by Trident's 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/
                                                                                                \1\          abundance survey) \2\               SI \3\
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                                                 Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals):
    Humpback Whale..................  Megaptera novaeangliae.  Hawai[revaps]i \5\.....  -, -, N             11,278 (0.56, 7,265,          127      27.09
                                                                                                             2020).
                                                               Mexico-North Pacific     T, D, Y             N/A (N/A, N/A, 2006)..        UND       0.57
                                                                \6\.
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                                                  Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
    Killer Whale....................  Orcinus orca...........  Eastern North Pacific    -, -, N             1,920 (N/A, 1,920,             19        1.3
                                                                Alaska Resident \7\.                         2019).
                                                               Eastern North Pacific    -, -, N             587 (N/A, 587, 2012)..        5.9        0.8
                                                                Gulf of Alaska,
                                                                Aleutian Islands and
                                                                Bering Sea Transient
                                                                \7\.
Family Phocoenidae (porpoises):
    Dall's Porpoise.................  Phocoenoides dalli.....  AK \8\.................  -, -, N             UND (UND, UND, 2015)..        UND         37
    Harbor Porpoise.................  Phocoena phocoena......  Gulf of Alaska.........  -, -, Y             31,046 (0.21, N/A,            UND         72
                                                                                                             1998).
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[[Page 88877]]

 
                                                               Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    Steller Sea Lion................  Eumetopias jubatus.....  Western \9\............  E, D, Y             52,932 (N/A, 52,932,          318        254
                                                                                                             2019).
Family Phocidae (earless seals):
    Harbor Seal.....................  Phoca vitulina.........  South Kodiak...........  -, -, N             26,448 (N/A, 22,351,          939        127
                                                                                                             2017).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual 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.
\4\ 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)).
\5\ New SAR in 2022 following North Pacific humpback whale stock structure changes.
\6\ Abundance estimates are based upon data collected more than 8 years ago and, therefore, current estimates are considered unknown.
\7\ Nest is based upon counts of individuals identified from photo-ID catalogs.
\8\ The best available abundance estimate is likely an underestimate for the entire stock because it is based upon a survey that covered only a small
  portion of the stock's range. \9\Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys.
\9\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys.

    As indicated above, all six species (with eight managed stocks) in 
table 2 temporally and spatially 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 area are included in table 5 
of the IHA application. While gray whales, North Pacific right whales, 
minke whales, fin whales, Cuvier's beaked whales, sperm whales, Pacific 
white-sided dolphins, and northern fur seals 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. These species are all considered to be rare 
(no sightings in recent years) within the project area. Take of these 
species has not been requested nor is proposed to be authorized and 
these species are not considered further in this document.
    Additional information relevant to our analyses (beyond that 
included above, in the application, and on NMFS website) is included 
below, as appropriate.

Humpback Whale

    On September 8, 2016, NMFS divided the once single species into 14 
distinct population segments (DPS) under the ESA, removed the species-
level listing as endangered, and, in its place, listed 4 DPSs as 
endangered and one DPS as threatened (81 FR 62259, September 8, 2016). 
The remaining nine DPSs were not listed. There are four DPSs in the 
North Pacific, including Mexico, which is listed as threatened, and 
Hawaii, which is not listed.
    The 2022 Alaska and Pacific SARs described a revised stock 
structure for humpback whales which modifies the previous stocks 
designated under the MMPA to align more closely with the ESA-designated 
DPSs (Caretta et al., 2023; Young et al., 2023). Specifically, the 
three previous North Pacific humpback whale stocks (Central and western 
North Pacific stocks and a CA/OR/WA stock) were replaced by five 
stocks, largely corresponding with the ESA-designated DPSs. These 
include Western North Pacific and Hawaii stocks and a Central America/
Southern Mexico-CA/OR/WA stock (which corresponds with the Central 
America DPS). The remaining two stocks, corresponding with the Mexico 
DPS, are the Mainland Mexico-CA/OR/WA and Mexico-North Pacific stocks 
(Caretta et al., 2023; Young et al., 2023). The former stock is 
expected to occur along the west coast from California to southern 
British Columbia, while the latter stock may occur across the Pacific, 
from northern British Columbia through the Gulf of Alaska and Aleutian 
Islands/Bering Sea region to Russia.
    The Hawai[revaps]i stock consists of one demographically 
independent population (DIP)--Hawai[revaps]i-southeast Alaska/northern 
British Columbia DIP and one unit--Hawai[revaps]i-north Pacific unit, 
which may or may not be composed of multiple DIPs (Wade et al., 2021). 
The DIP and unit are managed as a single stock at this time, due to the 
lack of data available to separately assess them and lack of compelling 
conservation benefit to managing them separately (NMFS, 2023; NMFS, 
2019; NMFS, 2022b). The DIP is delineated based on two strong lines of 
evidence: genetics and movement data (Wade et al., 2021). Whales in the 
Hawai[revaps]i-southeast Alaska/northern British Columbia DIP winter 
off Hawai[revaps]i and largely summer in southeast Alaska and northern 
British Columbia (Wade et al., 2021). The group of whales that migrate 
from Russia, western Alaska (Bering Sea and Aleutian Islands), and 
central Alaska (Gulf of Alaska excluding southeast Alaska) to 
Hawai[revaps]i have been delineated as the Hawai[revaps]i-North Pacific 
unit (Wade et al., 2021). There are a small number of whales that 
migrate between Hawa[revaps]i and southern British Columbia/Washington, 
but current data and analyses do not provide a clear understanding of 
which unit these whales belong to (Wade et al., 2021; Caretta et al., 
2023; Young et al., 2023).
    The Mexico-North Pacific unit is likely composed of multiple DIPs, 
based on movement data (Martien et al., 2021; Wade, 2021, Wade et al., 
2021). However, because currently available data and analyses are not 
sufficient to delineate or assess DIPs within the unit, it was 
designated as a single stock (NMFS, 2023a; NMFS, 2019; NMFS, 2022c). 
Whales in this stock winter off Mexico and the Revillagigedo 
Archipelago and summer primarily in Alaska waters (Martien et al., 
2021; Carretta et al., 2023; Young et al., 2023).

[[Page 88878]]

    Wild et al. (2023) identified the waters around and to the East of 
Kodiak Island (including the proposed project area) as a Biologically 
Important Area (BIA) for humpback whales for feeding during the months 
of May through September, with an importance score of 1 (the lowest of 
three possible scores (1, 2, or 3), reflecting an Intensity score of 2 
(indicating an area of moderate comparative significance) and a Data 
Support score of 1 (lower relative confidence in the available 
supporting data). While the majority of sightings occur outside of the 
Near Island Channel, a singular humpback whale was documented 
transiting the channel during the Kodiak Ferry Terminal construction in 
March 2016 (NMFS 2017).

Steller Sea Lion

    Steller sea lions were listed as threatened range-wide under the 
ESA on November 26, 1990 (55 FR 49204). Steller sea lions were 
subsequently partitioned into the western and eastern Distinct 
Population Segments (DPSs; western and eastern stocks) in 1997 (62 FR 
24345, May 5, 1997). The eastern DPS remained classified as threatened 
until it was delisted in November 2013. The western DPS (those 
individuals west of the 144[deg] W longitude or Cape Suckling, Alaska) 
was upgraded to endangered status following separation of the DPSs, and 
it remains endangered today. There is regular movement of both DPSs 
across this 144[deg] W longitude boundary (Jemison et al., 2013) 
however, due to the distance from this DPS boundary, it is likely that 
only western DPS Steller sea lions are present in the project area. 
Therefore, animals potentially affected by the project are assumed to 
be part of the western DPS. Sea lions from the eastern DPS, are not 
likely to be affected by the proposed activity and are not discussed 
further.
    Steller sea lions do not follow traditional migration patterns, but 
will move from offshore rookeries in the summer to more protected 
haulouts closer to shore in the winter. They use rookeries and haulouts 
as resting spots as they follow prey movements and take foraging trips 
for days, usually within a few miles of their rookery or haulout. They 
are generalist marine predators and opportunistic feeders based on 
seasonal abundance and location of prey. Steller sea lions forage in 
nearshore as well as offshore areas, following prey resources. They are 
highly social and are often observed in large groups while hauled out 
but alone or in small groups when at sea (NMFS 2022).
    Steller sea lions are frequent in the proposed project area as many 
have become habituated to the human activity at the seafood processing 
facilities. Steller sea lions regularly haul out on the Dog Bay float 
in St. Herman Harbor, which is approximately 792 m (2,600 ft) from the 
proposed project area. A bi-weekly census of Steller sea lions at the 
Dog Bay float conducted from November 2015 to June 2016, in association 
with the Kodiak Ferry Terminal project, revealed maximum numbers (>100) 
from mid-March through mid-June, with 5,111 total observations from 
November 2015 to June 2016 (NMFS 2019a). The highest average hourly 
number (11-15/hour) of sea lions within the entire Kodiak Ferry 
Terminal observation area occurred from February through April 2016 
(NMFS 2019a).

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in table 3.

                  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           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid,.
Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

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

[[Page 88879]]

document includes a quantitative analysis of the number of individuals 
that are expected to be taken by this activity. The Negligible Impact 
Analysis and Determination section considers the content of this 
section, the Estimated Take section, and the Proposed Mitigation 
section, to draw conclusions regarding the likely impacts of these 
activities on the reproductive success or survivorship of individuals 
and whether those impacts are reasonably expected to, or reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.

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. 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 to 20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include vibratory pile driving, vibratory pile removal, and DTH 
drilling. 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 raid rise/decay time that 
impulsive sounds do (ANSI, 1995; NIOSH, 1998; NMFS, 2018). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward, 1997; Southall, et al. 2007).
    Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak 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).
    DTH systems would also be used during the proposed construction. A 
DTH hammer is essentially a drill bit that drills through the bedrock 
using a rotating function like a normal drill, in concert with a 
hammering mechanism operated by a pneumatic (or sometimes hydraulic) 
component integrated into the DTH hammer to increase speed of progress 
through the substrate (i.e., it is similar to a ``hammer drill'' hand 
tool). The sounds produced by the DTH methods contain both a continuous 
non-impulsive component from the drilling action and an impulsive 
component from the hammering effect. Therefore, NMFS treats DTH systems 
as both impulsive and continuous, non-impulsive sound source types 
simultaneously.
    The likely or possible impacts of Trident's proposed activities on 
marine mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of the equipment and personnel; however, given there are no 
known pinniped haul-out sites in the vicinity of the proposed project 
site, visual and other non-acoustic stressors would be limited, and any 
impacts to marine mammals are expected to primarily be acoustic in 
nature.

Acoustic Effects

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving or drilling is the primary means by which 
marine mammals may be harassed from the Haines Borough specified 
activity. In general, animals exposed to natural or anthropogenic sound 
may experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al., 2007; Southall et al., 2019). In 
general, exposure to pile driving or drilling noise has the potential 
to result in auditory threshold shifts and behavioral reactions (e.g., 
avoidance, temporary cessation of foraging and vocalizing, changes in 
dive behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses, such 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 or drilling 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 (threshold shifts) followed 
by behavioral effects and potential impacts on habitat.
Auditory Effects
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018a), 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

[[Page 88880]]

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). When considering auditory effects for 
Trident's proposed activities, vibratory pile driving is considered a 
non-impulsive source, while DTH drilling are considered to have both 
non-impulsive and impulsive components.
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). PTS does not 
generally affect more than a limited frequency range, and an animal 
that has incurred PTS has incurred some level of hearing loss at the 
relevant frequencies; typically animals with PTS are not functionally 
deaf (Richardson et al., 1995; Au and Hastings, 2008). Available data 
from humans and other terrestrial mammals indicate that a 40 dB 
threshold shift approximates PTS onset (Ward et al., 1958, Ward et al., 
1959; Ward, 1960; Kryter et al., 1966; Miller, 1974; Ahroon et al., 
1996; Henderson et al., 2008). PTS criteria for marine mammals are 
estimates, as with the exception of a single study unintentionally 
inducing PTS in a harbor seal (Kastak et al., 2008), there are no 
empirical data measuring PTS in marine mammals 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; Southall et al., 2019), 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; Finneran et al., 
2002). As described in Finneran (2015), marine mammal studies have 
shown the amount of TTS increases with cumulative SEL 
(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.
    Many studies have examined noise-induced hearing loss in marine 
mammals (see Finneran (2015) and Southall et al. (2019) for summaries). 
TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 2013). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. For 
cetaceans, published data on the onset of TTS are limited to captive 
bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis) (Southall et al., 2019). For pinnipeds in water, 
measurements of TTS are limited to harbor seals, elephant seals 
(Mirounga angustirostris), bearded seals (Erignathus barbatus), and 
California sea lions (Zalophus californianus) (Kastak et al., 1999; 
Kastak et al., 2007; Kastelein et al., 2019b; Kastelein et al., 2019c; 
Reichmuth et al., 2019; Sills et al., 2020; Kastelein et al., 2021; 
Kastelein et al., 2022a; Kastelein et al., 2022b). These studies 
examine hearing thresholds measured in marine mammals before and after 
exposure to intense or long-duration sound exposures. The difference 
between the pre-exposure and post-exposure thresholds can be used to 
determine the amount of threshold shift at various post-exposure times.
    The amount and onset of TTS depends on the exposure frequency. 
Sounds at low frequencies, well below the region of best sensitivity 
for a species or hearing group, are less hazardous than those at higher 
frequencies, near the region of best sensitivity (Finneran and 
Schlundt, 2013). At low frequencies, onset-TTS exposure levels are 
higher compared to those in the region of best sensitivity (i.e., a low 
frequency noise would need to be louder to cause TTS onset when TTS 
exposure level is higher), as shown for harbor porpoises and harbor 
seals (Kastelein et al., 2019a; Kastelein et al., 2019c). Note that in 
general, harbor seals and harbor porpoises have a lower TTS onset than 
other measured pinniped or cetacean species (Finneran, 2015). In 
addition, TTS can accumulate across multiple exposures, but the 
resulting TTS will be less than the TTS from a single, continuous 
exposure with the same SEL (Mooney et al., 2009; Finneran et al., 2010; 
Kastelein et al., 2014; 2015). This means that TTS predictions based on 
the total, cumulative SEL will overestimate the amount of TTS from 
intermittent exposures, such as sonars and impulsive sources. 
Nachtigall et al. (2018) describe measurements of hearing sensitivity 
of multiple odontocete species (bottlenose dolphin, harbor porpoise, 
beluga, and false killer whale (Pseudorca crassidens) when a relatively 
loud sound was preceded by a warning sound. These captive animals were 
shown to reduce hearing sensitivity when warned of an impending intense 
sound. Based on these experimental observations of captive animals, the 
authors suggest that wild animals may dampen their hearing during 
prolonged exposures or if conditioned to anticipate intense sounds. 
Another study showed that echo-locating animals (including odontocetes) 
might have anatomical specializations that might allow for conditioned 
hearing reduction and filtering of low-frequency ambient noise, 
including increased stiffness and control of middle ear structures and 
placement of inner ear structures (Ketten et al., 2021). Data available 
on noise-induced hearing loss for mysticetes are currently lacking 
(NMFS, 2018). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species.

[[Page 88881]]

    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans, but such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. PTS typically occurs at exposure levels at least 
several decibels above (a 40-dB threshold shift approximates PTS onset; 
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB 
threshold shift approximates TTS onset; e.g., Southall et al., 2007). 
Based on data from terrestrial mammals, a precautionary assumption is 
that the PTS thresholds for impulsive sounds (such as impact pile 
driving pulses as received close to the source) are at least 6 dB 
higher than the TTS threshold on a peak-pressure basis and PTS 
cumulative sound exposure level thresholds are 15 to 20 dB higher than 
TTS cumulative sound exposure level thresholds (Southall et al., 2007). 
Given the higher level of sound or longer exposure duration necessary 
to cause PTS as compared with TTS, it is considerably less likely that 
PTS could occur.
    Furthermore, installing piles for this project requires a 
combination of vibratory pile driving and DTH drilling. For the 
project, these activities would not occur at the same time and there 
would likely be pauses in activities producing the sound during each 
day. Given these pauses and that many marine mammals are likely moving 
through the action area and not remaining for extended periods of time, 
the potential for any TS declines.
Behavioral Effects
    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; Southall et al., 2021).
    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, Southall et al. 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 studies involving marine 
mammal behavioral responses to sound, see: Southall et al., 2007; Gomez 
et al., 2016; and Southall et al., 2021.
    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 is informed by information on or estimates of the 
energetic requirements of the affected individuals and the relationship 
between prey availability, foraging effort and success, and the life 
history stage of the animal.
    The area likely impacted by the project is relatively small 
compared to the available habitat in the surrounding waters of the Near 
Island Channel.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal that have the potential to cause behavioral harassment, 
depending on their distance from pile driving activities. Cetaceans are 
not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming near the project site within the range of noise levels 
exceeding the acoustic thresholds. We recognize that pinnipeds in the 
water could be exposed to airborne sound that may result in behavioral 
harassment when looking with their heads above water. Most likely, 
airborne sound would cause behavioral responses similar to those 
discussed above in relation to underwater sound. For instance, 
anthropogenic sound could cause pinnipeds to exhibit changes in their 
normal behavior, such as reduction in vocalizations, or cause them to 
temporarily abandon the area and move further from the source. However, 
these animals would previously have been ``taken'' because of exposure 
to underwater sound above the behavioral harassment thresholds, which 
are in all cases larger than those associated with airborne sound. 
Thus, the behavioral harassment of these animals is already accounted 
for in these estimates of potential take. Therefore, we do not believe 
that authorization of incidental take resulting from airborne sound for 
pinnipeds is warranted, and airborne sound is not discussed further 
here.
    Auditory 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; Erbe et al., 
2016). 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., 
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

[[Page 88882]]

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.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore, 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand, 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking. 
Background sound levels in the project area are generally already 
elevated due to the cruise ships, passenger ferries, charter and 
commercial fishing vessels, barges, and freight vessels that frequent 
the area. Marine Mammal Habitat Effects.
    The proposed project would occur within the same footprint as 
existing marine infrastructure. The nearshore habitat where the 
proposed project would occur is an area of relatively high marine 
vessel traffic. Most marine mammals do not generally use the area 
within the immediate vicinity of the project area. Temporary, 
intermittent, and short-term habitat alteration may result from 
increased noise levels within the Level B harassment zones. Effects on 
marine mammals will be limited to temporary displacement from pile 
installation and removal noise, and effects on prey species will be 
similarly limited in time and space.
    Water Quality--Temporary and localized reduction in water quality 
will occur as a result of in-water construction activities. Most of 
this effect will occur during the installation and removal of piles and 
bedrock removal when bottom sediments are disturbed. The installation 
and removal of piles and bedrock removal will disturb bottom sediments 
and may cause a temporary increase in suspended sediment in the project 
area. During pile extraction, sediment attached to the pile moves 
vertically through the water column until gravitational forces cause it 
to slough off under its own weight. The small resulting sediment plume 
is expected to settle out of the water column within a few hours. 
Studies of the effects of turbid water on fish (marine mammal prey) 
suggest that concentrations of suspended sediment can reach thousands 
of milligrams per liter before an acute toxic reaction is expected 
(Burton, 1993).
    Impacts to water quality from DTH hammers are expected to be 
similar to those described for pile driving. Impacts to water quality 
would be localized and temporary and would have negligible impacts on 
marine mammal habitat. Effects to turbidity and sedimentation are 
expected to be short-term, minor, and localized. Since the currents are 
strong in the area, following the completion of sediment-disturbing 
activities, suspended sediments in the water column should dissipate 
and quickly return to background levels in all construction scenarios. 
Turbidity within the water column has the potential to reduce the level 
of oxygen in the water and irritate the gills of prey fish species in 
the proposed project area. However, turbidity plumes associated with 
the project would be temporary and localized, and fish in the proposed 
project area would be able to move away from and avoid the areas where 
plumes may occur. Therefore, it is expected that the impacts on prey 
fish species from turbidity, and therefore on marine mammals, would be 
minimal and temporary. In general, the area likely impacted by the 
proposed construction activities is relatively small compared to the 
available marine mammal habitat in southeast Alaska.
    Effects on Prey--Construction activities would produce continuous 
(i.e., vibratory pile driving) and impulsive (i.e., impact driving) 
sounds and a both continuous and impulsive sounds from DTH 
installation. Fish react to sounds that are especially strong and/or 
intermittent low-frequency sounds. Short duration, sharp sounds can 
cause overt or subtle changes in fish behavior and local distribution. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan, 2001, Scholik and Yan, 2002; Popper 
and Hastings, 2009). Sound pulses at received levels may cause 
noticeable changes in behavior (Pearson et al., 1992; Skalski et al., 
1992). SPLs of sufficient strength have been known to cause injury to 
fish and fish mortality.
    Impacts on marine mammal prey (i.e., fish or invertebrates) of the 
immediate area due to the acoustic disturbance are possible. The 
duration of fish or invertebrate avoidance or other disruption of 
behavioral patterns in this area after pile driving stops is unknown,

[[Page 88883]]

but a rapid return to normal recruitment, distribution and behavior is 
anticipated. Further, significantly large areas of fish and marine 
mammal foraging habitat are available in the nearby vicinity in the 
Near Island Channel.
    The duration of the construction activities is relatively short, 
with pile driving and removal activities expected last less than one-
year. Each day, construction would occur for no more than 12 hours 
during the day and pile driving activities would be restricted to 
daylight hours. The most likely impact to fish from pile driving 
activities at the project area would be temporary behavioral avoidance 
of the area. In general, impacts to marine mammal prey species are 
expected to be minor and temporary due to the short timeframe for the 
project.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect fish in the project area. 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 fish are expected to be minor or 
negligible. In addition, best management practices would be in effect, 
which would limit the extent of turbidity to the immediate project 
area.
    In summary, given the relatively short daily duration of sound 
associated with individual pile driving and events and the relatively 
small areas being affected, pile driving activities associated with the 
proposed action are not likely to have a permanent, adverse effect on 
any fish habitat, or populations of fish species. Thus, we conclude 
that impacts of the specified activity are not likely to have more than 
short-term adverse effects on any prey habitat or populations of prey 
species. Further, any impacts to marine mammal habitat are not expected 
to result in significant or long-term consequences for individual 
marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through the IHA, which will inform both 
NMFS' consideration of ``small numbers,'' and the negligible impact 
determinations. Harassment is the only type of take expected to result 
from these activities. Except with respect to certain activities not 
pertinent here, section 3(18) of the MMPA defines ``harassment'' as any 
act of pursuit, torment, or annoyance, which (i) has the potential to 
injure a marine mammal or marine mammal stock in the wild (Level A 
harassment); or (ii) has the potential to disturb a marine mammal or 
marine mammal stock in the wild by causing disruption of behavioral 
patterns, including, but not limited to, migration, breathing, nursing, 
breeding, feeding, or sheltering (Level B harassment).
    Authorized takes would be by Level B harassment only, in the form 
of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to pile driving activities. Based on the nature 
of the activity, 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. Generally speaking, Level B harassment take 
estimates based on these behavioral 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.
    Trident's proposed activity includes the use of continuous 
(vibratory pile driving) sources, and therefore the RMS SPL threshold 
of 120 dB re 1 [mu]Pa is applicable. DTH drilling has both continuous 
and intermittent (impulsive) components as discussed in the Description 
of Sound Sources section above. When evaluating Level B harassment, 
NMFS recommends treating DTH as a continuous source and applying the 
RMS SPL thresholds of 120 dB re 1 [mu]Pa.
    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). Trident's 
proposed activity includes the use of non-impulsive

[[Page 88884]]

(vibratory pile driving) sources. As described above, DTH includes both 
impulsive and non-impulsive characteristics. When evaluating Level A 
harassment, NMFS recommends treating DTH as an impulsive source.
    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 thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: L0-pk,flat: 219     Cell 2: LE,LF,24h: 199 dB.
                                          dB; LE, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: L0-pk,flat: 230     Cell 4: LE,MF,24h: 198 dB.
                                          dB; LE, MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: L0-pk,flat: 202     Cell 6: LE,HF,24h: 173 dB.
                                          dB; LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: L0-pk,flat: 218     Cell 8: LE,PW,24h: 201 dB.
                                          dB; LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: L0-pk,flat: 232     Cell 10: LE,OW,24h: 219 dB.
                                          dB; LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [mu]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[mu]Pa\2\s. In this table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
  is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
  hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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 weighted
  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 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 via sound generated by the 
primary components of the project (i.e., vibratory pile driving and 
removal, DTH drilling). The maximum (underwater) area ensonified above 
the thresholds for behavioral harassment referenced above is 125 km\2\ 
(48.26 mi\2\), that would be truncated by land masses that would 
obstruct underwater sound transmission and would extend into Near 
Island Channel and St. Paul Harbor (see figure 5 in Trident's 
application). Additionally, vessel traffic and other commercial and 
industrial activities in the project area may contribute to elevated 
background noise levels which may mask sounds produced by the project.
    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
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6-dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]). A 
practical spreading value of 15 is often used under conditions, such as 
the project site, where water increases with depth as the receiver 
moves away from the shoreline, resulting in an expected propagation 
environment that would lie between spherical and cylindrical spreading 
loss conditions. Practical spreading loss is assumed here.
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. In order to calculate 
the distances to the Level A harassment and the Level B harassment 
sound thresholds for the methods and piles being used in this project, 
the applicant and NMFS used acoustic monitoring data from other 
locations to develop proxy source levels for the various pile types, 
sizes and methods. The project includes vibratory and DTH pile 
installation of steel pipe piles and vibratory removal of steel pipe 
piles, steel H-piles, and timber piles. Source levels for each pile 
size and driving method are presented in table 5.

[[Page 88885]]



                      Table 5--Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
                                      Installation or     RMS SPL (re 1      SEL (re 1
            Pile type                     removal            [mu]Pa)       [mu]Pa\2\-sec)          Source
----------------------------------------------------------------------------------------------------------------
                                             Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
14-in timber pile................  Removal.............             162                 NA  Caltrans 2020.
14-in H-pile.....................  Removal.............             150                     Caltrans 2020.
16-in steel pile.................  Installation........             161                     NAVFAC 2015.
16-in steel pile.................  Removal.............                                     NAVFAC 2015.
24-in steel pile.................  Installation........                                     NAVFAC 2015.
----------------------------------------------------------------------------------------------------------------
                                                DTH Drilling \1\
----------------------------------------------------------------------------------------------------------------
16-in steel pile.................  Installation........             162                141  Heyvaert & Reyff
                                                                                             2021, Guan & Miner
                                                                                             2020.
24-in steel pile.................  Installation........                                154  Heyvaert & Reyff
                                                                                             2021.
----------------------------------------------------------------------------------------------------------------
\1\ Sound source levels for DTH were adjusted by -5 dB to reflect the use of the bubble curtain.

    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 driving, 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, and the 
resulting estimated isopleths, are reported below.

                                      Table 6--NMFS User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                                          Weighting
                                                            factor     Transmission      Number of     Activity
        Pile size and type         Spreadsheet tab used   adjustment       loss        piles per day   duration
                                                            (kHz)       coefficient                    (minutes)
----------------------------------------------------------------------------------------------------------------
14-in timber pile vibratory        A.1 Vibratory pile            2.5              15              25           2
 removal.                           driving.
14-in steel H-pile vibratory       A.1 Vibratory pile            2.5              15              20           2
 removal.                           driving.
16-in steel pipe pile vibratory    A.1 Vibratory pile            2.5              15              20           2
 removal.                           driving.
16-in steel pipe pile vibratory    A.1 Vibratory pile            2.5              15               5           2
 installation.                      driving.
24-in steel pipe pile vibratory    A.1 Vibratory pile            2.5              15               6           2
 installation (temporary).          driving.
24-in steel pipe pile vibratory    A.1 Vibratory pile            2.5              15               8           2
 removal (temporary).               driving.
24-in steel pipe pile vibratory    A.1 Vibratory pile            2.5              15               4           2
 installation.                      driving.
16-in steel pipe pile DTH          E.2 DTH pile driving            2              15               6          45
 installation.
24-in steel pipe pile DTH          E.2 DTH pile driving            2              15               6          30
 installation (temporary).
24-in steel pipe pile DTH          E.2 DTH pile driving            2              15               4          60
 installation.
----------------------------------------------------------------------------------------------------------------


                                              Table 7--Calculated Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Level A harassment zone (m)                               Level B
                        Activity                         --------------------------------------------------------------------------------   harassment
                                                           LF-cetaceans    MF-cetaceans    HF-cetaceans      Otariids         Phocids        zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-in timber pile vibratory removal.....................             7.1             0.6            10.4             4.3             0.3           6,310
14-in steel H-pile vibratory removal....................             1.0             0.1             1.4             0.6             0.0           1,000
16-in steel pipe pile vibratory removal.................             5.2             0.5             7.7             3.2             0.2           5,415
16-in steel pipe pile vibratory installation............             2.1             0.2             3.1             1.3             0.1
24-in steel pipe pile vibratory installation (temporary)             2.3             0.2             3.5             1.4             0.1
24-in steel pipe pile vibratory removal (temporary).....             2.8             0.3             4.2             1.7             0.1
24-in steel pipe pile vibratory installation............             1.8             0.2             2.6             1.1             0.1
16-in steel pipe pile DTH installation..................            47.0             1.7            56.0             1.8            25.2           6,310
24-in steel pipe pile DTH installation (temporary)......           264.1             9.4           314.5            10.3           141.3
24-in steel pipe pile DTH installation..................           319.9            11.4           381.0            12.5           171.2
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 88886]]

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 the take calculations.
    When available, peer-reviewed scientific publications were used to 
estimate marine mammal abundance in the project area. Data from 
monitoring reports from projects on the Kodiak Ferry Terminal were used 
as well as reports from other projects in Kodiak, Alaska.
    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and proposed for authorization. Tables for each species 
are presented to show the calculation of take during the project. Both 
density and occurrence data was considered in incidental take 
estimations. Density data were used when there was no occurrence data 
available, or when occurrence and density data were similar. The take 
calculations for this project are:

Incidental take estimate = group size * days of pile driving activity

Or

Incidental take estimate = (Activity Level B harassment area [km\2\] x 
estimated density [individuals/km\2\]) x days of pile driving activity

Humpback Whale

    Humpback whales are present in Kodiak year-round with peaks in the 
spring and fall. They are considered common in the project area, 
meaning there are multiple sightings every month, so they could occur 
daily in the project's action. In the proposed project area humpback 
whales are expected to occur at a density of 0.093 individuals per 
square kilometer area (Halpin et al. 2009). Therefore, using the 
equation given above, the total number of Level B harassment takes for 
humpback whales would be 14. In the action area it is estimated that 
the majority of whales (89 percent) will be from the Hawaii DPS, 11 
percent will be from the Mexico DPS, and 1 percent will be from the 
endangered Western North Pacific DPS (Wade 2021; Muto et al. 2022). 
Therefore 13 takes are assumed to be from the Hawaii DPS and 1 take 
from the Mexico DPS.
    The largest Level A harassment zone for humpback whales extends 
319.9 m from the noise source (table 7). All construction work would be 
shut down prior to a humpback whale entering the Level A harassment 
zone specific to the in-water activity underway at the time. In 
consideration of the infrequent occurrence of humpback whales in the 
project area and proposed shutdown requirements, no take by Level A 
harassment is anticipated or proposed for humpback whales.

Killer Whale

    Killer whales are present in Kodiak year-round and are considered 
common in the project area, meaning there are multiple sightings every 
month, so they could occur daily in the project's action. A single 
group of up to six killer whales are expected to occur in the proposed 
project area daily (Halpin et al. 2009). Therefore, using the equation 
given above, the total number of Level B harassment takes for killer 
whales would be 330. In the action area it is estimated that the 
majority of killer whales (80 percent) will be from the Alaska resident 
stock and 20 percent will be from the Gulf of Alaska/Aleutian Islands/
Bering Sea transient stock (Muto et al. 2022). Therefore 264 takes are 
assumed to be from the Alaska resident stock and 66 takes firm the Gulf 
of Alaska/Aleutian Islands/Bering Sea transient stock.
    The largest Level A harassment zone for killer whales extends 11.4 
m from the noise source (table 7). All construction work would be shut 
down prior to a killer whale entering the Level A harassment zone 
specific to the in-water activity underway at the time. In 
consideration of the small size of the Level A harassment zone and 
proposed shutdown requirements, no take by Level A harassment is 
anticipated or proposed for killer whale.

Harbor Porpoise

    Harbor porpoises are present in Kodiak year-round and are occur 
frequently in the project area, meaning there are multiple sightings 
every year, so they could occur monthly in the project's action. In the 
proposed project area harbor porpoises are expected to occur at a 
density of 0.4547 individuals per square kilometer area (Marine 
Geospatial Ecology Lab 2021). Therefore, using the equation given 
above, the total number of Level B harassment takes for harbor 
porpoises would be 65.
    The largest Level A harassment zone for harbor porpoise extends 381 
m from the noise source (table 7). All construction work would be shut 
down prior to a harbor porpoise entering the Level A harassment zone 
specific to the in-water activity underway at the time. In 
consideration of the relatively low anticipated exposure in the project 
area and the anticipated effectiveness of the proposed shutdown 
requirements, no take by Level A harassment is anticipated or proposed 
for harbor porpoise.

Dall's Porpoise

    Dall's porpoises are present in Kodiak year-round and are occur 
frequently in the project area, meaning there are multiple sightings 
every year, so they could occur monthly in the project's action. In the 
proposed project area Dall's porpoises are expected to occur at a 
density of 0.218 individuals per square kilometer area (Marine 
Geospatial Ecology Lab 2021). Therefore, using the equation given 
above, the total number of Level B harassment takes for Dall's porpoise 
would be 31.
    The largest Level A harassment zone for Dall's porpoise extends 381 
m from the noise source (table 7). All construction work would be shut 
down prior to a Dall's porpoise entering the Level A harassment zone 
specific to the in-water activity underway at the time. In 
consideration of the relatively low anticipated exposure in the project 
area and the anticipated effectiveness of the proposed shutdown 
requirements, no take by Level A harassment is anticipated or proposed 
for Dall's porpoise.

Harbor Seal

    Harbor seals are present in Kodiak year-round and are considered 
common in the project area, meaning there are multiple sightings every 
month, so they could occur daily in the project's action. In the 
proposed project area Dall's porpoises are expected to occur at a 
density of 0.1689 individuals per square kilometer area (Marine 
Geospatial Ecology Lab 2021). Therefore, using the equation given 
above, the total number of Level B harassment takes for harbor seals 
would be 24.
    The largest Level A harassment zone for harbor seals extends 171.2 
m from the noise source (table 7). All construction work would be shut 
down prior to a harbor seal entering the Level A harassment zone 
specific to the in-water activity underway at the time. In 
consideration of the relatively low anticipated exposure in the project 
area and the anticipated effectiveness of the proposed shutdown 
requirements, no take by Level A harassment is anticipated or proposed 
for harbor seals.

Steller Sea Lion

    Steller sea lions are present in Kodiak year-round and are 
considered common in the project area, meaning there are multiple 
sightings every month, so they could occur daily in the project's 
action. During construction at the Kodiak Ferry

[[Page 88887]]

Terminal (82 FR 10894, February 26, 2017) Steller sea lions were 
encountered daily during construction. Up to 40 Steller sea lions are 
expected to occur in the proposed project area daily (Marine Geospatial 
Ecology Lab 2021). Therefore, using the equation given above, the total 
number of Level B harassment takes for Steller sea lions would be 
2,200.
    The largest Level A harassment zone for harbor seals extends 12.5 m 
from the noise source (table 7). All construction work would be shut 
down prior to a Steller sea lion entering the Level A harassment zone 
specific to the in-water activity underway at the time. In 
consideration of the small Level A harassment isopleth and proposed 
shutdown requirements, no take by Level A harassment is anticipated or 
proposed for Steller sea lions.

                                     Table 8--Estimated Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                           Proposed take
                Common name                             Stock                  Stock          Level A         Level B     Total proposed   as percentage
                                                                           abundance \a\    harassment      harassment         take          of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale............................  Central North Pacific.......          10,103               0              12              13             0.1
                                            CA/OR/WA....................           4,973               0               2               1            0.07
Killer Whale..............................  Alaska Resident.............           1,920               0             264             264            13.8
                                            Gulf of Alaska/Aleutian                  587               0              66              66            11.2
                                             Islands/Bering Sea
                                             Transient.
Harbor porpoise...........................  Gulf of Alaska..............          31,946               0              65              65            0.08
Dall's porpoise...........................  Alaska......................          13,110               0              31              31            0.24
Steller sea lion..........................  Western U.S.................          52,932               0           2,200           2,200             4.2
Harbor seal...............................  South Kodiak Island.........          26,448               0              24              24            0.09
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Stock size is Nbest according to NMFS 2022 Stock Assessment Reports.

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. 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, as 
well as subsistence uses. 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.
    In addition to the measures described later in this section, 
Trident would employ the following standard mitigation measures:
     At the start of each day, the Contractor(s) would hold a 
briefing with the Lead Protected Species Observer (PSO) to outline the 
activities planned for that day.
     If poor weather conditions restrict the PSO's ability to 
make observations within the Level A harassment zone of pile driving 
(e.g., if there is excessive wind or fog), pile installation and 
removal would be halted.
    The following measures would apply to Trident's mitigation 
requirements:

Shutdown and Monitoring Zones

    Trident must establish shutdown zones and Level B monitoring zones 
for all pile driving activities. The purpose of a shutdown zone is 
generally to define an area within which shutdown of the activity would 
occur upon sighting of a marine animal (or in anticipation of an animal 
entering the defined area). Shutdown zones are based on the largest 
Level A harassment zone for each pile size/type and driving method, and 
behavioral monitoring zones are meant to encompass Level B harassment 
zones for each pile size/type and driving method, as shown in table 9. 
A minimum shutdown zone of 10 m would be required for all in-water 
construction activities to avoid physical interaction with marine 
mammals. Marine mammal monitoring will be conducted during all pile 
driving activities to ensure that marine mammals do not enter Level A 
shutdown zones, that marine mammal presence in the isopleth does not 
exceed authorized take. Proposed shutdown zones for each activity type 
are shown in table 9.
    Prior to pile driving, shutdown zones and monitoring zones will be 
established based on zones represented in table 9. Observers will 
survey the shutdown zones for at least 30 minutes before pile driving 
activities start. If marine mammals are found within the shutdown zone, 
pile driving will be delayed until the animal has moved out of the 
shutdown zone, either verified by an observer or by waiting until 15 
minutes has elapsed without a sighting. If a marine mammal approaches 
or enters the shutdown zone during pile driving, the activity will be 
halted. Pile driving may resume after the animal has moved out of and 
is moving away from the shutdown zone or after at least 15 minutes has 
passed since the last observation of the animal.
    All marine mammals would be monitored in the Level B harassment 
zones and throughout the area as far as visual monitoring can take 
place. If a marine mammal enters the Level B harassment zone, in-water 
activities would continue and PSOs would document the animal's presence 
within the estimated harassment zone.

[[Page 88888]]

    If a species for which authorization has not been granted, or a 
species which has been granted but the authorized takes are met, is 
observed approaching or within the Level B harassment zone, pile 
driving activities will be shutdown immediately. Activities will not 
resume until the animal has been confirmed to have left the area or 15 
minutes has elapsed with no sighting of the animal.

                                               Table 9--Shutdown and Level B Harassment Zones by Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Minimum shutdown zone
                                                         --------------------------------------------------------------------------------     Level B
               Pile size, type, and method                                                     High-                                        harassment
                                                           Low-frequency   Mid-frequency     frequency        Phocid          Otariid          zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barge movements, pile positioning, ect..................              10              10              10              10              10              10
14-in timber pile vibratory removal.....................              10              10              15              10              10           6,310
14-in steel H-pile vibratory removal....................              10              10              10              10              10           1,000
16-in steel pipe pile vibratory removal.................              10              10              10              10              10           5,415
16-in steel pipe pile vibratory installation............              10              10              10              10              10           5,415
24-in steel pipe pile vibratory installation (temporary)              10              10              10              10              10           5,415
24-in steel pipe pile vibratory removal (temporary).....              10              10              10              10              10           5,415
24-in steel pipe pile vibratory installation............              10              10              10              10              10           5,415
16-in steel pipe pile DTH installation..................              50              10              60              30              10           6,310
24-in steel pipe pile DTH installation (temporary)......             265              10             315             145              15           6,310
24-in steel pipe pile DTH installation..................             320              15             385             175              15           6,310
--------------------------------------------------------------------------------------------------------------------------------------------------------

Protected Species Observers

    The placement of PSOs during all pile driving activities (described 
in the Proposed Monitoring and Reporting section) would ensure that the 
entire shutdown zone is visible. Should environmental conditions 
deteriorate such that the entire shutdown zone would not be visible 
(e.g., fog, heavy rain), pile driving would be delayed until the PSO is 
confident marine mammals within the shutdown zone could be detected.
    PSOs would monitor the full shutdown zones and as much of the Level 
B harassment zones as possible. Monitoring zones provide utility for 
observing by establishing monitoring protocols for areas adjacent to 
the shutdown zones. Monitoring enables observers to be aware of and 
communicate the presence of marine mammals in the project areas outside 
the shutdown zones and thus prepare for a potential cessation of 
activity should the animal enter the shutdown zone.

Pre- and Post-Activity Monitoring

    Monitoring must take place from 30 minutes prior to initiation of 
pile driving activities (i.e., pre-clearance monitoring) through 30 
minutes post-completion of pile driving. Prior to the start of daily 
in-water construction activity, or whenever a break in pile driving of 
30 minutes or longer occurs, PSOs would observe the shutdown and 
monitoring zones for a period of 30 minutes. The shutdown zone would be 
considered cleared when a marine mammal has not been observed within 
the zone for a 30-minute period. If a marine mammal is observed within 
the shutdown zones, pile driving activity would be delayed or halted. 
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).

Bubble Curtain

    A bubble curtain must be employed during all impact DTH activities 
to interrupt the acoustic pressure and reduce impact on marine mammals. 
The bubble curtain must distribute air bubbles around 100 percent of 
the piling circumference for the full depth of the water column. The 
lowest bubble ring must be in contact with the mudline for the full 
circumference of the ring. The weights attached to the bottom ring must 
ensure 100 percent substrate contact. No parts of the ring or other 
objects may prevent full substrate contact. Air flow to the bubblers 
must be balanced around the circumference of the pile.
    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);

[[Page 88889]]

     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

    Monitoring shall be conducted by NMFS-approved observers in 
accordance with the monitoring plan and Section 5 of the IHA. Trained 
observers shall be placed from the best vantage point(s) practicable to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable through communication with the equipment operator. 
Observer training must be provided prior to project start, and shall 
include instruction on species identification (sufficient to 
distinguish the species in the project area), description and 
categorization of observed behaviors and interpretation of behaviors 
that may be construed as being reactions to the specified activity, 
proper completion of data forms, and other basic components of 
biological monitoring, including tracking of observed animals or groups 
of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal activities. In addition, observers 
shall record all incidents of marine mammal occurrence, regardless of 
distance from activity, and shall document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving/
removal 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.
    Between one and five PSOs will be on duty depending on the size of 
the monitoring zone. Locations from which PSOs would be able to monitor 
for marine mammals are readily available from publicly accessible 
shoreside areas at the Near Island Channel and surrounding waters. 
Monitoring locations would be selected by the Contractor during pre-
construction. PSOs would monitor for marine mammals entering the Level 
B harassment zones; the position(s) may vary based on construction 
activity and location of piles or equipment.
    PSOs would scan the waters using binoculars, and/or spotting 
scopes, and would use a handheld range-finder device to verify the 
distance to each sighting from the project site. All PSOs would be 
trained in marine mammal identification and behaviors and are required 
to have no other project-related tasks while conducting monitoring. In 
addition, monitoring would be conducted by qualified observers, who 
would be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator via a radio. Trident 
would adhere to the following observer qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required;
    (ii) One PSO would be designated as the lead PSO or monitoring 
coordinator and that observer must have prior experience working as an 
observer;
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience; and
    (iv) Trident must submit observer Curriculum Vitaes for approval by 
NMFS.
    Additional standard observer qualifications include:
     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 and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; 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.

Data Collection

    PSOs would use approved data forms to record the following 
information:
     Dates and times (beginning and end) of all marine mammal 
monitoring.
     PSO locations during marine mammal monitoring.
    Construction activities occurring during each daily observation 
period, including how many and what type of piles were driven or 
removed and by what method (i.e., vibratory or DTH).
     Weather parameters and water conditions.
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting.
     Distance and bearings of each marine mammal observed to 
the pile being driven or removed.
     Description of marine mammal behavior patterns, including 
direction of travel.
     Age and sex class, if possible, of all marine mammals 
observed.
     Detailed information about implementation of any 
mitigation triggered (such as shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal if 
any.

Reporting

    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities. It would include an overall description of work completed, 
a narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring.
     Construction activities occurring during each daily 
observation period, including the number and type of piles driven or 
removed and by what method (i.e., vibratory driving) and the total 
equipment duration for cutting for each pile.
     PSO locations during marine mammal monitoring.
     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;
     Upon observation of a marine mammal, the following 
information: Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting; Time of sighting; Identification

[[Page 88890]]

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 bearing of each 
marine mammal observed relative to the pile being driven for each 
sighting (if pile driving was occurring at time of sighting); Estimated 
number of animals (min/max/best estimate); Estimated number of animals 
by cohort (adults, juveniles, neonates, group composition, etc.); 
Animal's closest point of approach and estimated time spent within the 
harassment zone; 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.
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific 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 
final report would constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury, serious injury or mortality, Trident 
would immediately cease the specified activities and report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinator. The report would include the following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with Trident to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Trident would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that Trident discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (e.g., in less than 
a moderate state of decomposition as described in the next paragraph), 
Trident would immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
and the NMFS Alaska Stranding Hotline and/or by email to the Alaska 
Regional Stranding Coordinator. The report would include the same 
information identified in the paragraph above. Activities would be able 
to continue while NMFS reviews the circumstances of the incident. NMFS 
would work with Trident to determine whether modifications in the 
activities are appropriate.
    In the event that Trident discovers an injured or dead marine 
mammal and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), Trident would report the incident 
to the Chief of the Permits and Conservation Division, Office of 
Protected Resources, NMFS, and the NMFS Alaska Stranding Hotline and/or 
by email to the Alaska Regional Stranding Coordinator, within 24 hours 
of the discovery. Trident would provide photographs, video footage (if 
available), or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network

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).
    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. There is little information about the nature or severity of 
the impacts, or the size, status, or structure of any of these species 
or stocks that would lead to a different analysis for this activity.
    Pile driving and removal activities associated with the project as 
outlined previously, have the potential to disturb or displace marine 
mammals. Specifically, the specified activities may result in take, in 
the form of Level B harassment from underwater sounds generated from 
pile driving and removal. Level A harassment is extremely unlikely 
given the small size of the Level A harassment isopleths and the 
required mitigation measures designed to minimize the possibility of 
injury to marine mammals (see Proposed Mitigation section). No 
mortality is anticipated given the nature of the activity. Pile 
installation and removal activities are likely to result in the Level B 
harassment of marine mammals that move into the ensonified zone, 
primarily in the form of disturbance or displacement of marine mammals. 
Take would occur within a limited, confined area of each stock's range. 
Level B harassment would be reduced to the level of least practicable 
adverse impact through use of mitigation measures described herein. 
Further, the amount of take authorized is small when compared to stock 
abundance.
    Based on reports in the literature as well as monitoring from other 
similar

[[Page 88891]]

activities, behavioral disturbance (i.e., level B harassment) would 
likely be limited to reactions such as increased swimming speeds, 
increased surfacing time, or decreased foraging (if such activity were 
occurring) (e.g., Thorson and Reyff, 2006; HDR, Inc. 2012; Lerma, 2014; 
ABR, 2016). Most likely for pile driving, individuals would simply move 
away from the sound source and be temporarily displaced from the areas 
of pile driving, although even this reaction has been observed 
primarily only in association with impact pile driving. The pile 
driving activities analyzed here are similar to, or less impactful 
than, numerous other construction activities conducted in Alaska, which 
have taken place with no observed severe responses of any individuals 
or known long-term adverse consequences. Level B harassment would be 
reduced to the level of least practicable adverse impact through use of 
mitigation measures described herein and, if sound produced by project 
activities is sufficiently disturbing, animals are likely to simply 
avoid the area while the activity is occurring. While vibratory driving 
associated with the proposed project may produce sound at distances of 
many kilometers from the project site, thus overlapping with some 
likely less-disturbed habitat, the project site itself is located in a 
busy harbor and the majority of sound fields produced by the specified 
activities are close to the harbor. Animals disturbed by project sound 
would be expected to avoid the area and use nearby higher-quality 
habitats.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may cause some fish or invertebrates 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, the 
relatively small area of the habitat that may be affected, and the 
availability of nearby habitat of similar or higher value, the impacts 
to marine mammal habitat are not expected to cause significant or long-
term negative consequences.
    The waters around Kodiak Island are part of the Alaska humpback 
whale feeding BIA (Ferguson et al., 2015). Humpback whales are present 
around Kodiak, although the majority of sightings have occurred outside 
of Near Island Channel. The area of the BIA that may be affected by the 
proposed project is small relative to the overall area of the BIA. The 
humpback whale feeding BIA is active between May and November while the 
proposed project is scheduled to occur between March and June, 
resulting in only 2 months of overlap. Additionally, pile driving 
associated with the project is expected to take only 55 days, further 
reducing the temporal overlap with the BIA. Therefore, the proposed 
project is not expected to have significant adverse effects on the 
foraging of Alaska humpback whale. No areas of specific biological 
importance (e.g., ESA critical habitat, other BIAs, or other areas) for 
any other species are known to co-occur with the project area.
    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, mortality, or Level A harassment is 
anticipated or authorized;
     The anticipated incidents of Level B harassment would 
consist of, at worst, temporary modifications in behavior that would 
not result in fitness impacts to individuals;
     The ensonifed areas from the project are very small 
relative to the overall habitat ranges of all species and stocks;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat or any other areas of known biological 
importance; and
     The proposed mitigation measures are expected to reduce 
the effects of the specified activity to the level of least practicable 
adverse impact.
    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.
    Table 8 demonstrates the number of animals that could be exposed to 
received noise levels that could cause Level B harassment for the 
proposed work in Kodiak, Alaska. Our analysis shows that less than 14 
percent of each affected stock could be taken by harassment. The 
numbers of animals proposed to be taken for these stocks would be 
considered small relative to the relevant stock's abundances, even if 
each estimated taking occurred to a new individual--an extremely 
unlikely scenario.
    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

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    In the Kodiak area sea lions and harbor seals are available for 
subsistence harvest under the MMPA. Limited subsistence harvests of 
marine mammals outside of Near Island Channel has occurred in the past, 
with the most recent recorded/documented harvests of marine mammals in 
Kodiak in 2011. The proposed activity will take place in Near Island 
Channel, and no activities overlap with current subsistence hunting 
areas; therefore,

[[Page 88892]]

there are no relevant subsistence uses of marine mammals adversely 
impacted by this action. The proposed project is not likely to 
adversely impact the availability of any marine mammal species or 
stocks that are commonly used for subsistence purposes or to impact 
subsistence harvest of marine mammals in the region.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the proposed mitigation and 
monitoring measures, NMFS has preliminarily determined that there will 
not be an unmitigable adverse impact on subsistence uses from Trident's 
proposed activities.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species, in this case with the Alaska Regional 
Office.
    NMFS is proposing to authorize take of western DPS of Steller sea 
lions, which are listed under the ESA. The Permits and Conservation 
Division has requested initiation of section 7 consultation with the 
Alaska Regional Office for the issuance of this IHA. NMFS will conclude 
the ESA consultation prior to reaching a determination regarding the 
proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to Trident for conducting Bunkhouse Dock replacement 
project in Kodiak, Alaska between March 1, 2024 and February 29, 2025, 
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 
construction 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, 1-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 1 year from expiration 
of the initial IHA).
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    Upon review of the request for renewal, the status of the affected 
species or stocks, and any other pertinent information, NMFS determines 
that there are no more than minor changes in the activities, the 
mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: December 19, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-28336 Filed 12-22-23; 8:45 am]
BILLING CODE 3510-22-P