```

[Federal Register Volume 89, Number 245 (Friday, December 20, 2024)]
[Notices]
[Pages 104090-104105]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-30455]

-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XE184]

Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Coast Guard Fast Response 
Cutter Homeporting in Seward and Sitka, Alaska

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

ACTION: Notice; issuance of incidental harassment authorizations.

-----------------------------------------------------------------------

SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued two incidental harassment authorizations (IHAs) to 
the United States Coast Guard (USCG) to incidentally harass marine 
mammals during construction activities associated with fast response 
cutter (FRC) homeporting in Seward and Sitka, Alaska.

DATES: These authorizations are effective from September 1, 2026, 
through August 31, 2027, and from March 1, 2027, through February 29, 
2028.

ADDRESSES: Electronic copies of the application and supporting 
documents, as well as a list of the references cited in this document, 
may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems accessing these documents, please call 
the contact listed below.

FOR FURTHER INFORMATION CONTACT: Alyssa Clevenstine, 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 monitoring and 
reporting of the takings. The definitions of all applicable MMPA 
statutory terms cited above are included in the relevant sections 
below.

Summary of Request

    On January 19, 2024, NMFS received a request from the USCG for two 
IHAs to take marine mammals incidental to pile driving (installation 
and removal) associated with construction of two FRC homeporting docks 
in Seward and Sitka, Alaska. Following NMFS' review of the application, 
the USCG submitted revised versions on April 3, 2024, June 6, 2024, and 
June 11, 2024. The application was deemed adequate and complete on June 
11, 2024. The USCG's request is for take of 11 species (18 stocks) of 
marine mammals by Level B harassment and, for a subset of 5 of these 
species, Level A harassment. Neither the USCG nor NMFS expect serious 
injury or mortality to result from this activity and, therefore, IHAs 
are appropriate.

Description of the Specified Activity

Overview

    The USCG plans to construct shore-side facilities and associated 
infrastructure at Moorings Seward to homeport one FRC located in the 
Seward Marine Industrial Center (SMIC) boat basin, and demolishing and 
constructing shore-side facilities at Moorings Sitka in Sitka Harbor to 
support a second FRC. The shore-side facilities and associated 
infrastructure for Moorings Seward will be constructed parallel to the 
existing SMIC dock. Construction of a new floating dock at Moorings 
Sitka will be attached to the existing pier. The projects are needed to 
provide adequate vessel berthing capability to support modern USCG 
cutters and ultimately, readiness as part of the USCG's overall 
mission. The USCG plans to use a variety of methods, including impact, 
down-the-hole (DTH), and vibratory pile driving, to install and remove 
piles, including concrete, steel, plastic, and timber piles. These 
methods of pile driving will introduce underwater sounds that may 
result in take, by Level A and Level B harassment, of marine mammals. 
Pile removal may occur by vibratory, cutting, or clipping methods. 
Cutting and clipping are not anticipated to have the potential to 
result in incidental take of marine mammals because they are either 
above water, do not last for sufficient duration to present the 
reasonable potential for disruption of behavioral patterns, do not 
produce sound levels with likely potential to result in marine mammal 
harassment, or some combination of the above.
    Each IHA will be effective for 1 year from the date of issuance. 
Pile extraction and installation activities at Moorings Seward will 
occur for a total of 22 non-consecutive days, of which pile removal is 
anticipated to take 2 days and pile installation is anticipated to take 
a maximum of 20 days (15 days to complete installation plus 5 
additional days to account for potential weather-related delays). Pile 
removal and installation activities at Moorings Sitka will occur for a 
total of 117 non-consecutive days, of which pile removal is anticipated 
to take 3 days and pile installation is anticipated to take a maximum 
of 114 days (89 days to complete installation plus 25 additional days 
to account for potential weather-related delays).
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed IHA (89 FR 
60359, July 25, 2024). Since that time, no changes have been made to 
the planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for the 
description of the specific activity.

[[Page 104091]]

    Planned mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Mitigation and 
Monitoring and Reporting sections).

Comments and Responses

    A notice of NMFS' proposal to issue two IHAs to the USCG was 
published in the Federal Register on July 25, 2024 (89 FR 60359). That 
notice described, in detail, the USCG's activity, the marine mammal 
species that may be affected by the activity, and the anticipated 
effects on marine mammals. In that notice, we requested public input on 
the request for authorizations described therein, our analyses, the 
proposed authorizations, and any other aspect of the notice of proposed 
IHAs, and requested that interested persons submit relevant 
information, suggestions, and comments.
    During the 30-day public comment period, NMFS did not receive any 
substantive comments on the proposed IHAs.

Changes From the Proposed IHA to Final IHA

    There were two changes from the proposed IHAs: the dates for 
planned work at both locations and the estimated take at both locations 
(four species (four stocks) at Moorings Seward, four species (five 
stocks) at Moorings Sitka). The former was made upon the applicant's 
request and resulted in changes to the dates planned for in-water work 
at Moorings Seward to occur from March 1, 2027, through February 29, 
2028, and at Moorings Sitka to occur from September 1, 2026, through 
August 31, 2027.
    Changes to estimated take were made as a result of NMFS' 
incorporation of the 2024 Updated Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Updated 
Technical Guidance; NMFS, 2024). On May 3, 2024, NMFS published and 
solicited public comment on its draft Updated Technical Guidance (89 FR 
36762), which included updated thresholds and weighting functions to 
inform auditory injury (AUD INJ) estimates. The 2024 Updated Technical 
Guidance was finalized on October 24, 2024 (89 FR 84872) and represents 
the best available science, replacing the 2018 Technical Guidance 
(NMFS, 2018). To best ensure we have considered an appropriate estimate 
of take by Level A harassment, in consideration of the best available 
science, we conducted basic comparative calculations using the 2024 
Updated Technical Guidance for the purposes of understanding the number 
of takes by Level A harassment (AUD INJ) that would be predicted. The 
relevant updated thresholds and weighting functions may be found in the 
executive summary of the 2024 Updated Technical Guidance, on pages 3 
through 6. We also considered whether modifications to mitigation zones 
would be appropriate in light of the 2024 Updated Technical Guidance. 
Based on the outcome of these comparisons using the 2024 Updated 
Technical Guidance, updated take numbers are presented in tables 11 and 
12 of this notice (see Estimated Take of Marine Mammals section). For 
the purposes of the negligible impact analyses for a given species or 
stock, the higher of any two Level A harassment estimates is 
considered. No updates were made to planned mitigation zones in 
consideration of the 2024 Updated Technical Guidance (see Mitigation 
section).
    The use of the 2024 Updated Technical Guidance resulted in an 
increase in the size of the Level A harassment isopleth(s) for certain 
species groups, which therefore increased take by Level A harassment 
for the following species, for which we relied on density data and the 
estimated ensonified areas: harbor porpoise at Moorings Seward and 
Dall's porpoise at Moorings Sitka. It also resulted in an increase in 
the size of the Level A harassment isopleth and resulting take by Level 
A harassment of Steller sea lions at both locations, for which we 
relied on occurrence data. Take by Level A harassment of low-frequency 
cetaceans was not expected under the 2018 Technical Guidance and is not 
expected under the 2024 Updated Technical Guidance; the Level A 
harassment isopleth during DTH activities for this group decreased.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species or stocks for which take is expected and 
authorized for the specified activities at Seward and Sitka, and 
summarizes information related to the population or stock, including 
regulatory status under the MMPA and Endangered Species Act (ESA), and 
potential biological removal (PBR), where known. PBR is defined by the 
MMPA as the maximum number of animals, not including natural 
mortalities, that may be removed from a marine mammal stock while 
allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS' SARs). While no serious injury or 
mortality is anticipated or authorized here, PBR and annual serious 
injury and mortality from anthropogenic sources are included here as 
gross indicators of the status of the species 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 
either NMFS' U.S. Alaska SARs or U.S. Pacific SARs. All values 
presented in table 1 are the most recent available at the time of 
publication (including from the draft 2023 SARs) and are available 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

[[Page 104092]]

                                     Table 1--Marine Mammal Species \1\ Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Family Eschrichtiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale..........................  Eschrichtius robustus..  Eastern North Pacific..  -, -, N             26,960 (0.05, 25,849,         801        131
                                                                                                             2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fin Whale...........................  Balaenoptera physalus..  Northeast Pacific......  E, D, Y             UND (UND, UND, 2013)..        UND        0.6
Humpback Whale......................  Megaptera novaeangliae.  Hawai[revaps]i.........  -, -, N             11,278 (0.56, 7,265,          127      27.09
                                                                                                             2020).
Humpback Whale......................  Megaptera novaeangliae.  Mexico-North Pacific...  T, D, Y             N/A (N/A, N/A, 2006)..        UND       0.57
Minke Whale \5\.....................  Balaenoptera             Alaska.................  -, -, N             N/A (N/A, N/A, N/A)...        UND          0
                                       acutorostrata.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer Whale........................  Orcinus orca...........  Eastern North Pacific    -, -, N             1,920 (N/A, 1,920,             19        1.3
                                                                Alaska Resident.                             2019).
Killer Whale........................  Orcinus orca...........  Eastern North Pacific    -, -, N             587 (N/A, 587, 2012)..        5.9        0.8
                                                                Gulf of Alaska,
                                                                Aleutian Islands and
                                                                Bering Sea Transient.
Killer Whale........................  Orcinus orca...........  Eastern Northern         -, -, N             302 (N/A, 302, 2018)..        2.2        0.2
                                                                Pacific Northern
                                                                Resident.
Killer Whale........................  Orcinus orca...........  West Coast Transient...  -, -, N             349 (N/A, 349, 2018)..        3.5        0.4
Pacific White-Sided Dolphin.........  Lagenorhynchus           North Pacific..........  -, -, N             26,880 (N/A, N/A,             UND          0
                                       obliquidens.                                                          1990).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dall's Porpoise \6\.................  Phocoenoides dalli.....  Alaska.................  -, -, N             UND (UND, UND, 2015)..        UND         37
Harbor Porpoise.....................  Phocoena phocoena......  Gulf of Alaska.........  -, -, Y             31,046 (0.21, N/A,            UND         72
                                                                                                             1998).
Harbor Porpoise \7\.................  Phocoena phocoena......  Yakutat/Southeast        -, -, N             N/A (N/A, N/A, 1997)..        UND       22.2
                                                                Alaska Offshore Waters.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Northern Fur Seal...................  Callorhinus ursinus....  Eastern Pacific........  -, D, Y             626,618 (0.2, 530,         11,403        373
                                                                                                             376, 2019).
Steller Sea Lion....................  Eumetopias jubatus.....  Western................  E, D, Y             49,837 (N/A, 49,837,          299        267
                                                                                                             2022).
Steller Sea Lion....................  Eumetopias jubatus.....  Eastern................  -, -, N             36,308 (N/A, 36,308,        2,178       93.2
                                                                                                             2022).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Seal.........................  Phoca vitulina.........  Prince William Sound...  -, -, N             44,756 (N/A, 41,776,        1,253        413
                                                                                                             2015).
Harbor Seal.........................  Phoca vitulina.........  Sitka/Chatham Strait...  -, -, N             13,289 (N/A, 11,883,          356         77
                                                                                                             2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal SARs online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region.
  CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
  CV associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ No population estimates have been made for the number of minke whales in the entire North Pacific. Some information is available on the numbers of
  minke whales in some areas of Alaska, but in the 2009, 2013, and 2015 offshore surveys, so few minke whales were seen during the surveys that a
  population estimate for the species in this area could not be determined (Rone et al., 2017). Therefore, this information is N/A (not available).
\6\ Previous abundance estimates covering the entire stock's range are no longer considered reliable and the current estimates presented in the SARs and
  reported here only cover a portion of the stock's range. Therefore, the calculated Nmin and PBR is based on the 2015 survey of only a small portion of
  the stock's range. PBR is considered to be biased low since it is based on the whole stock whereas the estimate of mortality and serious injury is for
  the entire stock's range.
\7\ Abundance estimates assumed that detection probability on the trackline was perfect; work is underway on a corrected estimate. Additionally,
  preliminary data results based on environmental DNA analysis show genetic differentiation between harbor porpoise in the northern and southern regions
  on the inland waters of southeast Alaska. Geographic delineation is not yet known. Data to evaluate population structure for harbor porpoise in
  Southeast Alaska have been collected and are currently being analyzed. Should the analysis identify different population structure than is currently
  reflected in the Alaska SARs, NMFS will consider how to best revise stock designations in the future.

    As indicated above, all 11 species (with 18 managed stocks) in 
table 1 temporally and spatially co-occur with the activities to the 
degree that take is reasonably likely to occur at either location. All 
species that could potentially occur in the project areas are included 
in section 4 and tables 3-1 and 3-2 of the USCG's IHA application.
    A detailed description of the species likely to be affected by the 
USCG project, including brief introductions to the species and relevant 
stocks as well as available information regarding population trends and 
threats, and information regarding local occurrence, were provided in 
the Federal Register notice for the proposed IHA (89 FR 60359, July 25, 
2024); since that time, we are not aware of any changes in the status 
of these species and stocks; therefore, detailed descriptions are not 
provided here. Please refer to that Federal Register notice for these 
descriptions. Please also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

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

[[Page 104093]]

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 auditory or auditory 
evoked potential techniques) or estimated hearing ranges (behavioral 
response data, anatomical modeling, etc.). NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups and, 
in 2024, updated the hearing group terminology (NMFS, 2024). 
Generalized hearing ranges were chosen based on the approximately 65-
decibel (dB) threshold from the composite audiograms, previous analysis 
in NMFS (2018), and/or data from Southall et al. (2007) and Southall et 
al. (2019). Marine mammal hearing groups and their associated hearing 
ranges based on the Updated Technical Guidance are provided in table 2.

                  Table 2--Marine Mammal Hearing Groups
                              [NMFS, 2024]
------------------------------------------------------------------------
         Hearing group [supcaret]            Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen        7 Hz to 36 ** kHz.
 whales).
High-frequency (HF) cetaceans (dolphins,    150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
Very High-frequency (VHF) cetaceans (true   200 Hz to 165 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger
 & L. australis).
Phocid pinnipeds (PW) (underwater) (true    40 Hz to 90 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea    60 Hz to 68 kHz.
 lions and fur seals).
------------------------------------------------------------------------
[supcaret] Southall et al. (2019) indicates that as more data become
  available there may be separate hearing group designations for Very
  Low-Frequency cetaceans (blue, fin, right, and bowhead whales) and Mid-
  Frequency cetaceans (sperm, killer, and beaked whales). However, at
  this point, all baleen whales are part of the LF cetacean hearing
  group, and sperm, killer, and beaked whales are part of the HF
  cetacean hearing group. Additionally, recent data indicates that as
  more data become available for Monachinae seals, separate hearing
  group designations may be appropriate for the two phocid subfamilies
  (Ruscher et al., 2021; Sills et al., 2021).
* 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 the ~65-dB threshold from composite
  audiogram, previous analysis in NMFS (2018), and/or data from Southall
  et al. (2007) and Southall et al. (2019). Additionally, animals are
  able to detect very loud sounds above and below that ``generalized''
  hearing range.
** NMFS is aware that the National Marine Mammal Foundation successfully
  collected preliminary hearing data on two minke whales during their
  third field season (2023) in Norway. These data have implications for
  not only the generalized hearing range for low-frequency cetaceans but
  also on their weighting function. However, at this time, no official
  results have been published. Furthermore, a fourth field season (2024)
  has concluded, where more data were collected. Thus, it is premature
  for us to propose any changes to our current Updated Technical
  Guidance. However, mysticete hearing data is identified as a special
  circumstance that could merit reevaluating the acoustic criteria in
  this document. Therefore, we anticipate that once the data from both
  field seasons are published, it will likely necessitate updating this
  document (i.e., likely after the data gathered in the summer 2024
  field season and associated analysis are published).

    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2024) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the USCG's construction 
activities have the potential to result in harassment of marine mammals 
in the vicinity of the project areas. The notice of proposed IHA (89 FR 
60359, July 25, 2024) included a discussion of the effects of 
anthropogenic noise on marine mammals and the potential effects of 
underwater noise from the USCG's construction activities on marine 
mammals and their habitat. That information and analysis is referenced 
in this final IHA determination and is not repeated here; please refer 
to the notice of proposed IHA (89 FR 60359, July 25, 2024).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through the IHAs, which informed NMFS' consideration of 
``small numbers,'' the negligible impact determinations, and impacts on 
subsistence uses.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the acoustic sources (i.e., vibratory and impact pile driving, DTH) 
has the potential to result in disruption of behavioral patterns for 
individual marine mammals. There is also some potential for AUD INJ 
(Level A harassment) to result, primarily for high-frequency species 
and phocids, because predicted AUD INJ zones are large and these 
species could enter the Level A harassment zones and remain undetected 
for a sufficient duration to incur AUD INJ due to their small size and 
inconspicuous nature. Although AUD INJ could occur for low-frequency 
species due to large predicted AUD INJ zones associated with DTH, due 
to their large size, conspicuous nature, and planned mitigation (i.e., 
large shutdown zones, boat-based protected species observers (PSOs)), 
it is assumed that all low-frequency species would be visually detected 
and, therefore, taking by Level A harassment would be eliminated. The 
planned mitigation and monitoring measures are expected to minimize the 
severity of the taking to the extent practicable.
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
authorized 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 authorized take estimates.

[[Page 104094]]

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 AUD INJ (which includes, but is not 
limited to, permanent threshold shift (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; Southall et al., 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 temporary 
threshold shift (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.
    The USCG's planned activity includes the use of continuous 
(vibratory and DTH) and impulsive (impact driving and DTH) sources, and 
therefore the 120 and 160 dB re 1 [mu]Pa (RMS) thresholds, 
respectively, are applicable.
    Level A harassment--NMFS' 2024 Updated Technical Guidance (NMFS, 
2024) identifies dual criteria to assess AUD INJ (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). The USCG's planned activity includes the 
use of impulsive (impact driving and DTH) and non-impulsive (vibratory 
and DTH) sources.
    These criteria are provided in table 3 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in the 2024 Updated Technical Guidance, which may be accessed 
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools.

                            Table 3--Summary of Marine Mammal AUD INJ Onset Criteria
                                                  [NMFS, 2024]
----------------------------------------------------------------------------------------------------------------
                                                        AUD INJ onset criteria * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: L0-pk,flat: 222     Cell 2: LLF,24h: 197 dB.
                                          dB; LLF,24h: 183 dB.
High-Frequency (HF) Cetaceans..........  Cell 3: L0-pk,flat: 230     Cell 4: LHF,24h: 201 dB.
                                          dB; LHF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans....  Cell 5: L0-pk,flat: 202     Cell 6: LVHF,24h: 181 dB.
                                          dB; LVHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: L0-pk,flat: 223     Cell 8: LPW,24h: 195 dB.
                                          dB; LPW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: L,0-pk,flat: 230    Cell 10: LOW,24h: 199 dB.
                                          dB; LOW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for
  calculating AUD INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure
  level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-
  impulsive sources.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [mu]Pa (underwater) and 20 [mu]Pa (in air),
  and weighted cumulative sound exposure level (L) has a reference value of 1[mu]Pa\2\s (underwater) and 20
  [mu]Pa\2\s (in air). In this table, criteria are abbreviated to be more reflective of International
  Organization for Standardization standards (ISO, 2017; ISO, 2020). The subscript ``flat'' is being included to
  indicate peak sound pressure are flat weighted or unweighted within the generalized hearing range of marine
  mammals underwater (i.e., 7 Hz to 165 kHz) or in air (i.e., 42 Hz to 52 kHz). The subscript associated with
  cumulative sound exposure level criteria indicates the designated marine mammal auditory weighting function
  (LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours.
  The weighted cumulative sound exposure level criteria 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 criteria 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 (TL) 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the project. Marine 
mammals are expected to be affected via sound generated by the primary 
components of the project (i.e., impact pile driving, vibratory pile 
driving, vibratory pile removal, and DTH).
    In order to calculate distances to the Level A harassment and Level 
B harassment thresholds for the methods and piles planned for this 
project, NMFS used acoustic monitoring data from other locations to 
develop source levels for the various pile types, sizes, and methods 
(tables 4-7).
    NMFS recommends treating DTH systems as both impulsive and 
continuous, non-impulsive sound source types simultaneously. Thus, 
impulsive thresholds are used to evaluate Level A harassment, and 
continuous thresholds are used to evaluate Level B harassment. With 
regards to DTH mono-hammers, NMFS

[[Page 104095]]

recommends proxy levels for Level A harassment based on available data 
regarding DTH systems of similar sized piles and holes (Denes et al., 
2019; Guan and Miner, 2020; Heyvaert and Reyff, 2021; Reyff, 2020; 
Reyff and Heyvaert, 2019).

 Table 4--Observed Non-Impulsive Sound Levels and Durations for In-Water Activities Likely To Occur at Moorings
                                                     Seward
----------------------------------------------------------------------------------------------------------------
                                                                                            Average
                                                                          RMS SPL (dB re    duration   Piles per
             In-water activity                   Pile size and type        1 [mu]Pa) at     per pile      day
                                                                               10 m        (seconds)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Extraction \a\.............  14-inch steel guide pile....             160        1,800          5
Vibratory Pile Settling \a\...............  30-inch concrete guide pile.             163          600          2
Rock socket drill \b\ (non-impulsive        30-inch concrete guide pile.             174   \c\ 10,800          2
 component).
----------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ NMFS, 2024.
\b\ NMFS, 2022.
\c\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that
  simultaneously contain both non-impulsive and impulsive components.

               Table 5--Observed Impulsive Sound Levels and Durations for Pile Installation Activities Likely To Occur at Moorings Seward
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    SELsingle-strike
                                                                     Peak (dB re 1   RMS (dB re 1        (dB re 1     Strikes per    Maximum   Piles per
          Installation method                Pile size and type      [mu]Pa) at 10   [mu]Pa) at 10   [mu]Pa\2\s) at       day        strikes      day
                                                                           m               m              10 m                      per pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rock socket drill \a\..................  30-inch concrete guide                194             174               164  \c\ 216,000     108,000          2
                                          pile.
Impact hammer proofing \b\.............  30-inch concrete guide                198             186               173           10           5          2
                                          pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ NMFS, 2022.
\b\ NMFS, 2024.
\c\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that simultaneously contain both non-
  impulsive and impulsive components.

 Table 6--Observed Non-Impulsive Sound Levels and Durations for In-Water Activities Likely To Occur at Moorings
                                                      Sitka
----------------------------------------------------------------------------------------------------------------
                                                                                            Average
                                                                          RMS SPL (dB re    duration   Piles per
             In-water activity                   Pile size and type        1 [mu]Pa) at     per pile      day
                                                                               10 m        (seconds)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Extraction \a\.............  12-inch timber piles........             162        1,800          5
Vibratory Pile Settling \b\...............  30-inch concrete guide and               163          600          2
                                             structure pile.
Rock socket drill \c\ (non-impulsive        30-inch concrete guide and               174       10,800          2
 component).                                 structure pile.
----------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ NMFS, 2024.
\b\ NMFS, 2022.
\c\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that
  simultaneously contain both non-impulsive and impulsive components.

                Table 7--Observed Impulsive Sound Levels and Durations for Pile Installation Activities Likely To Occur at Moorings Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    SELsingle-strike
                                                                      Peak (re 1     RMS (dB re 1        (dB re 1     Strikes per    Maximum   Piles per
          Installation method                Pile size and type      [mu]Pa) at 10   [mu]Pa) at 10   [mu]Pa\2\s) at       day        strikes      day
                                                                           m               m              10 m                      per pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact drive \a\.......................  13-inch plastic fender                177             153                NA          200         100          2
                                          pile.
Impact drive \a\.......................  14-inch timber guide pile             180             170               160          320         160          2
Rock socket drill \b\..................  30-inch concrete guide                194             174               164  \d\ 216,000     108,000          2
                                          pile.
Impact hammer proofing \c\.............  30-inch concrete guide                198             186               173           10           5          2
                                          pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ Caltrans, 2020.
\b\ NMFS, 2022.
\c\ NMFS, 2024.
\d\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that simultaneously contain both non-
  impulsive and impulsive components.

    Level B Harassment Zones--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 x log10 (R1/R2),

Where:

[[Page 104096]]

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15 (-4.5 dB per doubling of distance). 
This value results in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions, which 
is the most appropriate assumption for the USCG's planned activities. 
This analysis uses practical spreading loss, a standard assumption 
regarding sound propagation for similar environments, to estimate 
transmission of sound through water. The Level B harassment zones and 
approximate amount of area ensonified for the planned underwater 
activities are shown in tables 8 and 9.
    Level A Harassment Zones--The ensonified area associated with Level 
A harassment is more technically challenging to predict due to the need 
to account for a duration component. Therefore, NMFS developed an 
optional User Spreadsheet tool to accompany the Updated 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. A weighting adjustment 
factor of 2.5 or 2, a standard default value for vibratory pile driving 
and removal or impact driving and DTH respectively, was used to 
calculate Level A harassment areas. 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 and DTH, the optional Updated 
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 AUD INJ. Inputs used in the optional Updated 
User Spreadsheet tool (e.g., number of piles per day, duration and/or 
strikes per pile) are presented in tables 4-7, and the resulting 
estimated isopleths and total ensonified areas are reported below in 
tables 8 and 9.

  Table 8--Projected Distances to Level A Harassment Isopleths Using 2018 and 2024 Technical Guidance and Level B Harassment Isopleths by Marine Mammal
                                                            Hearing Group at Moorings Seward
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                 Total
                                         Distance to level A for     Distance to     Distance to      Distance to    Distance to    Level B   ensonified
               Activity                             LF             level A for HF    level A for    level A for PW   level A for   Distance      area
                                                                                         VHF                              OW          (m)       (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile extraction.............  10.8 m...................             1 m            16 m             6.6 m        0.5 m     4,641.6        1.94
                                        (14.6 m).................         (5.6 m)        (11.9 m)          (18.8 m)      (6.3 m)
DTH (Impulsive component) concrete....  1,945.5..................            69.2         2,317.4  1,041.2 (1,722.1         75.8    39,810.7      * 2.26
                                        (1,938.5 m)..............       (247.3 m)     (2,999.8 m)                m)    (641.9 m)
Vibratory settling concrete...........  4.5 m....................           0.4 m           6.6 m             2.7 m        0.2 m     7,356.4      * 2.26
                                        (6 m)....................         (2.3 m)         (4.9 m)           (7.8 m)      (2.6 m)
Impact driver proofing concrete.......  10 m.....................           0.4 m          11.9 m             5.3 m        0.4 m       541.2       0.11
                                                                          (1.3 m)        (15.4 m)           (8.8 m)      (3.3 m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note 1: Abbreviations: LF = low-frequency cetaceans, HF = high-frequency cetaceans, VHF = very high-frequency cetaceans, PW = phocid pinnipeds in water,
  OW = otariid pinnipeds in water.
Note 2: Isopleths based on NMFS (2018) are shown above updated isopleths from NMFS (2024), which are italicized in parentheses below the original
  isopleths.
* Total harassment areas are the same despite having varying radii because the maximum distance intersects with the other side of Resurrection Bay near
  Seward resulting in the same areal extent.

  Table 9--Projected Distances to Level A Harassment Isopleths Using 2018 and 2024 Technical Guidance and Level B Harassment Isopleths by Marine Mammal
                                                             Hearing Group at Moorings Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                              Total
           Activity               Distance to       Distance to       Distance to       Distance to      Distance to        Level B      ensonified area
                                level A for LF    level A for HF    level A for VHF   level A for PW    level A for OW    distance (m)       (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile extraction....  14.7 m..........  1.3 m...........  21.7 m..........  6.9 m...........  0.6 m..........  6,309.6 m......  4.17
                               (19.8 m)........  (7.6 m).........  (16.2 m)........  (25.5 m)........  (8.6 m)........
Impact drive plastic.........  13.6 m..........  0.5 m...........  16.2 m..........  7.3 m...........  0.5 m..........  3.4 m..........  0
                               (13.5 m)........  (1.7 m).........  (21 m)..........  (12 m)..........  (4.5 m)........
Impact drive timber..........  13.7 m..........  0.5 m...........  16.3 m..........  7.3 m...........  0.5 m..........  46.4 m.........  0.01
                               (13.6 m)........  (1.7 m).........  (21.1 m)........  (12.1 m)........  (4.5 m)........
DTH (Impulsive component)....  1,945.5 m.......  69.2 m..........  2,317.4 m.......  1,041.2 m.......  75.8 m.........  39,810.7 m.....  6.31
                               (1,938.5 m).....  (247.3 m).......  (2,999.8 m).....  (1,722.1 m).....  (641.9 m)......
Vibratory settling concrete..  4.5 m...........  0.4 m...........  6.6 m...........  2.7 m...........  0.2 m..........  7,356.4 m......  4.89
                               (6 m)...........  (2.3 m).........  (4.9 m).........  (7.8 m).........  (2.6 m)........
Impact driver proofing         10 m............  0.4 m...........  11.9 m..........  5.3 m...........  0.4 m..........  541.2 m........  0.33
 concrete.                                       (1.3 m).........  (15.4 m)........  (8.8 m).........  (3.3 m)........
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note 1: Abbreviations: LF = low-frequency cetaceans, HF = high-frequency cetaceans, VHF = very high-frequency cetaceans, PW = phocid pinnipeds in water,
  OW = otariid pinnipeds in water.
Note 2: Isopleths based on NMFS (2018) are shown with updated isopleths from NMFS (2024) are italicized in parentheses.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
informed the take calculations. Available information regarding marine 
mammal occurrence and density in the project areas includes monitoring 
data, prior

[[Page 104097]]

incidental take authorizations, and ESA consultations on previous 
projects. When local density information was not available, data 
aggregated in the Navy's Marine Mammal Species Density Database (Navy, 
2019; Navy, 2020) for the Northwest or Gulf of Alaska Testing and 
Training areas or nearby proxies from the monitoring data were used. 
Daily occurrence probability of each marine mammal species is based on 
consultation with previous monitoring reports, local researchers and 
marine professionals. Occurrence probability estimates at Moorings 
Sitka are based on conservative density approximations for each species 
and factor in historic data of occurrence, seasonality, and group size 
in Sitka Sound and Sitka Channel. A summary of occurrence is shown in 
table 10. Group size is based on the best available published research 
for these species and their presence in the project areas.

                            Table 10--Estimated Species Occurrence or Density Values
----------------------------------------------------------------------------------------------------------------
               Species                          Stock               Moorings Seward           Moorings Sitka
----------------------------------------------------------------------------------------------------------------
Steller sea lion a b.................  Western................  2 individuals/day......  2 groups of 2
                                                                                          individuals/day of
                                                                                          either stock
Steller sea lion a b.................  Eastern................  0......................  2 groups of 2
                                                                                          individuals/day of
                                                                                          either stock
Northern fur seal....................  Eastern Pacific........  0......................  1 individual/month
Harbor seal..........................  Prince William Sound...  48.95 individuals/day..  0
Harbor seal \a\......................  Sitka/Chatham Strait...  0......................  2 groups of 2.1
                                                                                          individuals/day
Killer whale.........................  Alaska Resident........  1 group of 7             1 group of 6.6
                                                                 individuals/week of      individuals/week of
                                                                 either stock.            any stock
Killer whale.........................  Gulf of Alaska,          1 group of 7             1 group of 6.6
                                        Aleutian Islands, and    individuals/week of      individuals/week of
                                        Bering Sea Transient.    either stock.            any stock
Killer whale.........................  Northern Resident......  0......................  1 group of 6.6
                                                                                          individuals/week of
                                                                                          any stock
Killer whale.........................  West Coast Transient...  0......................  1 group of 6.6
                                                                                          individuals/week of
                                                                                          any stock
Pacific white-sided dolphin..........  North Pacific..........  3 individuals/day......  0
Harbor porpoise......................  Gulf of Alaska.........  0.4547 individuals/      0
                                                                 km\2\.
Harbor porpoise......................  Yakutat/Southeast        0......................  1 group of 5
                                        Alaska Offshore Waters.                           individuals/week
Dall's porpoise......................  Alaska.................  0.25 individuals/day...  0.121 individuals/km\2\
Sperm whale..........................  North Pacific..........  0......................  0.002 individuals/km\2\
Humpback whale \c\...................  Hawai'i................  1 individual/day of      1 group of 3.4
                                                                 either stock.            individuals/week of
                                                                                          either stock
Humpback whale \c\...................  Mexico-North Pacific...  1 individual/day of      1 group of 3.4
                                                                 either stock.            individuals/week of
                                                                                          either stock
Gray whale...........................  Eastern North Pacific..  0.0155 individuals/      1 group of 3.5
                                                                 km\2\.                   individuals/2 weeks
Fin whale............................  Northeast Pacific......  0.068 individuals/km\2\  0.0001 individuals/
                                                                                          km\2\
Minke whale..........................  Alaska.................  0.006 individuals/km\2\  1 group of 3.5
                                                                                          individuals/2 weeks
----------------------------------------------------------------------------------------------------------------
Note: Occurrence value presented as individuals per unit time; density value presented as individuals per square
  kilometer.
\a\ Likelihood of one group per day in the Level A harassment zone and likelihood of two groups per day in the
  Level B harassment zone.
\b\ Steller sea lion stock attribution is 100 percent Western DPS at Moorings Seward; 97.8 percent Eastern DPS
  and 2.2 percent Western DPS at Moorings Sitka.
\c\ Humpback whale stock attribution is 89 percent Hawai'i and 11 percent Mexico-North Pacific at Moorings
  Seward; 98 percent Hawai'i and 2 percent Mexico-North Pacific at Moorings Sitka.

    Gray whale--Members of the ENP stock have a small chance to occur 
at the northern end of Resurrection Bay near Moorings Seward, with an 
estimated density of 0.0155 individuals/km\2\.
    During 190 hours of observation from 1994 to 2002 from Sitka's 
Whale Park, only three gray whales were observed (Straley et al., 
2017). However, Straley and Wild (unpublished data) note that since 
2014, the number of gray whale sightings in Sitka Sound has increased 
to an estimated 150-200 individuals in 2021 and 2022. Based on this and 
recent monitoring data collected near Sitka, the estimated occurrence 
of gray whales at Moorings Sitka is one group of 3.5 individuals every 
2 weeks.
    Fin whale--Fin whales have the potential to occur at both Moorings 
Seward and Moorings Sitka. Based on survey data, fin whales in the 
vicinity of Moorings Seward are anticipated to occur at a density of 
0.068/km\2\ and fin whales in the vicinity of Moorings Sitka are 
anticipated to occur at a density of 0.0001/km\2\.
    Humpback whale--Humpback whales found in the project areas are 
predominantly members of the Hawai[revaps]i DPS (89 percent at Moorings 
Seward, 98 percent probability at Moorings Sitka), which is not listed 
under the ESA. However, based on a comprehensive photo-identification 
study, members of the Mexico DPS, which is listed as threatened, have a 
small potential to occur in all project locations (11 percent at 
Moorings Seward, 2 percent at Moorings Sitka) (Wade, 2016), and it is 
estimated that one individual per day of either stock may occur at 
Moorings Seward while one group of 3.5 individuals per 2 weeks of 
either stock may occur at Moorings Sitka.
    Minke whale--Minke whales are generally found in shallow, coastal 
waters within 200 m (656 ft) of shore (Zerbini et al., 2006). Dedicated 
surveys for cetaceans in southeast Alaska found that minke whales were 
scattered throughout inland waters from Glacier Bay and Icy Strait to 
Clarence Strait, with small concentrations near the entrance of Glacier 
Bay. Surveys took place in spring, summer, and fall, and minke whales 
were present in low numbers in all seasons and years (Dahlheim et al., 
2009). Additionally, minke whales were observed during the Biorka 
Island Dock Replacement Project at the mouth of Sitka Sound (Turnagain 
Marine Construction, 2018). Minke whale density at Moorings Seward is 
estimated as 0.006 individuals/km\2\ while estimated occurrence at 
Moorings Sitka is one group of 3.5 individuals every 2 weeks.

[[Page 104098]]

    Killer whale--Killer whales occur along the entire coast of Alaska 
(Braham and Dahlheim, 1982) and four stocks may be present in the 
project areas as follows: (1) Alaska Resident stock--both locations; 
(2) Gulf of Alaska, Aleutian Islands, and Bering Sea Transient stock--
both locations; (3) Northern Resident--Sitka only; and (4) West Coast 
Transient stock--Sitka only.
    The Alaska Resident stock occurs from southeast Alaska to the 
Aleutian Islands and Bering Sea. The Gulf of Alaska, Aleutian Islands, 
and Bering Sea Transient stock occurs from the northern British 
Columbia coast to the Aleutian Islands and Bering Sea. The Northern 
Resident stock occurs from Washington north through part of southeast 
Alaska. The West Coast Transient stock occurs from California north 
through southeast Alaska (Muto et al., 2020). One group of seven 
individuals per week from either the Alaska Resident stock or the Gulf 
of Alaska, Aleutian Islands, and Bering Sea Transient stock are 
estimated to occur at Moorings Seward. One group of 6.6 individuals per 
week from any of the four stocks are estimated to occur at Moorings 
Sitka.
    Pacific white-sided dolphin--Pacific white-sided dolphins are 
anticipated to occur in the vicinity of Moorings Seward only. Previous 
construction monitoring reported by NOAA as an appropriate proxy for 
Moorings Seward is three individuals per day. During 8 years of surveys 
near Sitka, Straley et al. (2017) only documented seven Pacific white-
sided dolphins, therefore, we do not reasonably expect the species to 
occur in the vicinity of Moorings Sitka.
    Dall's porpoise--Dall's porpoise are anticipated to occur in the 
vicinity of both locations. At Moorings Seward, the expected occurrence 
rate is approximately 0.25 animals per day, and the average group size 
throughout Alaskan waters is estimated to be between 2 and 12 
individuals. We therefore estimate that approximately one group of up 
to six individuals could occur over 22 non-consecutive days of in-water 
work. At Moorings Sitka, the estimated density of Dall's porpoise is 
0.121 individuals/km\2\.
    Harbor porpoise--Only the Yakutat/Southeast Alaska Offshore Waters 
stock and the Gulf of Alaska stock are expected to be encountered in 
the project areas. The Gulf of Alaska stock range includes Moorings 
Seward while the Yakutat/Southeast Alaska Offshore Waters stock's range 
includes Moorings Sitka. The estimated density of harbor porpoises at 
Moorings Seward is 0.4547/km\2\ and the estimated occurrence at 
Moorings Sitka is one group of five individuals every week.
    Northern fur seal--Northern fur seals are not expected near 
Moorings Seward and one individual per month is estimated to occur at 
Moorings Sitka.
    Steller sea lion--Only the Western stock of Steller sea lion is 
expected to occur at Moorings Seward with an estimated occurrence of 
two individuals per day. Both the Western and Eastern stocks may occur 
at Moorings Sitka, which is located in the Central Outer Coast 
population mixing zone delineated by Hastings et al. (2020). Based on 
these data, 2.2 percent of Steller sea lions near Sitka are expected to 
be from the Western stock while 97.8 percent are expected to be from 
the Eastern stock (Hastings et al., 2020), and it is estimated that two 
groups of two individuals per day may occur at Moorings Sitka in the 
Level A harassment zone.
    Harbor seal--There are 12 stocks of harbor seals in Alaska, 2 of 
which occur in the project areas: (1) the Prince William Sound stock 
ranges from Elizabeth Island off the southwest tip of the Kenai 
Peninsula to Cape Fairweather, including Moorings Seward; and (2) the 
Sitka/Chatham Strait stock ranges from Cape Bingham south to Cape 
Ommaney, extending inland to Table Bay on the west side of Kuiu Island 
and north through Chatham Strait to Cube Point off the west coast of 
Admiralty Island, and as far east as Cape Bendel on the northeast tip 
of Kupreanof Island, which includes Moorings Sitka. Daily occurrence of 
harbor seals at Moorings Sitka is estimated as 48.95 individuals/day 
and at Moorings Sitka 2 groups of 2.1 individuals/day are estimated 
based on previous monitoring in the vicinity, with a likelihood of 2 
groups per day in the Level A harassment zone.

Take Estimation

    Here we describe how the information provided above was synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and is authorized.
    Neither the applicant nor NMFS have fine-scale data to 
quantitatively assess the number of animals in the relatively small 
predicted Level A harassment zones at either location. Therefore, we 
assumed that, for cryptic species (e.g., Steller sea lion, Pacific 
white-sided dolphin (Moorings Seward only), harbor seal, harbor 
porpoise), up to 25 percent of the animals that entered the Level B 
harassment zone could enter the Level A harassment zone undetected, 
potentially accumulating sound exposure that rises to the level of 
Level A harassment.
    For species with observational data, the following equation was 
used to estimate take by Level B harassment, where daily occurrence is 
measured as individuals per day:

Estimated take = (daily occurrence x number of days)-Level A harassment 
takes

    For species with observational data, the following equation was 
used to estimate take by Level A harassment, where daily occurrence is 
multiplied by the number of days of work, which is then multiplied by 
25 percent:

Estimated take = (daily occurrence x number of days) x 25 percent

    For species with density data, the following equation was used to 
estimate take by Level B harassment, where ensonified area is measured 
as km\2\:

Estimated take = (species density x daily ensonified Level B harassment 
area x number of days)--Level A harassment takes

    For species with density data, the following equation was used to 
estimate take by Level A harassment, where species density is 
multiplied by the daily ensonified Level A harassment area multiplied 
by the number of days of work:

Estimated take = species density x daily ensonified Level A harassment 
area x number of days

    Table 11 summarizes the amount of take authorized by both Level A 
and Level B harassment, as well as the percentage of each stock 
expected to be taken, at Moorings Seward.

                            Table 11--Authorized Take of Marine Mammals by Level A and Level B Harassment at Moorings Seward
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                 SAR       Percentage of
                     Species                                     Stock                  Level A      Level B       Total      abundance     population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion................................  Western...........................           10           34           44       49,837            0.09
Harbor seal.....................................  Prince William Sound..............          245          833         1078       44,756            2.41
Killer whale *..................................  Alaska Resident...................            0           21           21        1,920            1.09

[[Page 104099]]

 
Killer whale *..................................  Eastern North Pacific Gulf of                 0            7            7          587            1.19
                                                   Alaska, Aleutian Islands and
                                                   Bering Sea Transient.
Pacific white-sided dolphin.....................  North Pacific.....................           15           51           66       26,880            0.25
Harbor porpoise.................................  Gulf of Alaska....................            8           15           23       31,046            0.07
Dall's porpoise.................................  Alaska............................            1            5            6          UND             UND
Humpback whale..................................  Hawai[revaps]i....................            0           20           20       11,278            0.18
Humpback whale..................................  Mexico-North Pacific..............            0            2            2          N/A             N/A
Gray whale......................................  Eastern North Pacific.............            0            1            1       26,960               0
Fin whale.......................................  Northeast Pacific.................            0            3            3          UND             UND
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Humpback whale stock attribution: 89 percent Hawai[revaps]i and 11 percent Mexico-North Pacific.
* Percent of stock impacted for killer whales was estimated assuming each stock is taken in proportion to its population size at each location from the
  total take. At Moorings Seward, the Alaska Resident and Gulf of Alaska stocks are the only stocks present. Of these, the Alaska Resident stock
  represents approximately 76 percent of the available animals, while the Gulf of Alaska stock represents approximately 23 percent. Takes were then
  calculated for each site based on the proportional representation of available stocks, so for Moorings Seward, this results in 21 Level B harassment
  takes of the Alaska Resident stock of killer whale and 7 Level B harassment takes of the Gulf of Alaska stock of killer whale. Total takes for each
  stock are shown as a percentage of the stock size.

    Table 12 summarizes amount of take authorized by both Level A and 
Level B harassment, as well as the percentage of each stock expected to 
be taken, at Moorings Sitka.

                             Table 12--Authorized Take of Marine Mammals by Level A and Level B Harassment at Moorings Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                           Percentage of
                  Species                               Stock                 Level A         Level B          Total       SAR abundance    population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion..........................  Western.....................               2               6               8          49,837            0.02
Steller sea lion..........................  Eastern.....................              82             270             352          36,308            0.97
Northern fur seal.........................  Eastern Pacific.............               0               3               3         626,618               0
Harbor seal...............................  Sitka/Chatham Strait........              88             272             360          13,289            2.71
Killer whale *............................  Alaska Resident.............               0              55              55           1,920            2.86
Killer whale *............................  Eastern North Pacific Gulf                 0              17              17             587            2.90
                                             of Alaska, Aleutian Islands
                                             and Bering Sea Transient.
Killer whale *............................  Northern Resident...........               0               8               8             302            2.65
Killer whale *............................  West Coast Transient........               0              10              10             349            2.87
Harbor porpoise...........................  Yakutat/Southeast Alaska                  15              20              35             N/A             N/A
                                             Offshore Waters.
Dall's porpoise...........................  Alaska......................              24              42              66             UND             UND
Humpback whale............................  Hawai[revaps]i..............               0              43              43          11,278            0.38
Humpback whale............................  Mexico-North Pacific........               0               1               1             N/A             N/A
Gray whale................................  Eastern North Pacific.......               0              22              22          26,960            0.08
Minke whale...............................  Alaska......................               0              22              22             N/A             N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Steller sea lion stock attribution: 97.8 percent Eastern DPS and 2.2 percent Western DPS at Moorings Sitka. Humpback whale stock attribution: 98
  percent Hawai[revaps]i and 2 percent Mexico-North Pacific.
* Percent of stock impacted for killer whales was estimated assuming each stock is taken in proportion to its population size at each location from the
  total take. At Moorings Sitka, the Alaska Resident, Gulf of Alaska, Northern Resident, and West Coast Transient stocks are expected, and the Alaska
  Resident stock represents approximately 60 percent of the available animals, the Gulf of Alaska stock represents approximately 19 percent, the
  Northern Resident stock represents approximately 10 percent, and the West Coast Transient represents approximately 11 percent. Takes were then
  calculated based on the proportional representation of available stocks, which results in 55 Level B harassment takes of the Alaska Resident stock, 17
  Level B harassment takes of the Gulf of Alaska stock, 8 Level B harassment takes of the Northern Resident stock, and 10 Level B harassment takes of
  the West Coast Transient stock. Total takes for each stock are shown as a percentage of the stock size.

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

[[Page 104100]]

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.
    For each IHA, the USCG must:
     Ensure that construction supervisors and crews, the 
monitoring team, and relevant USCG staff are trained prior to the start 
of all pile driving and DTH activity, so that responsibilities, 
communication procedures, monitoring protocols, and operational 
procedures are clearly understood. New personnel joining during the 
project must be trained prior to commencing work;
     Employ one to five PSOs and establish monitoring locations 
as described in the application and the IHA. The USCG must monitor the 
project area to the maximum extent possible based on the required 
number of PSOs, required monitoring locations, and environmental 
conditions. For all pile driving and removal at least one PSO must be 
used. The PSO will be stationed as close to the activity as possible;
     The placement of the PSOs during all pile driving and 
removal and DTH activities will ensure that the entire shutdown zone is 
visible during pile installation;
     Monitoring must take place from 30 minutes prior to 
initiation of pile driving or DTH activity (i.e., pre-activity 
monitoring) through 30 minutes post-activity of pile driving or DTH 
activity;
     Pre-activity monitoring must be conducted during periods 
of visibility sufficient for the lead PSO to determine that the 
shutdown zones indicated in table 13 are clear of marine mammals. Pile 
driving and DTH may commence following 30 minutes of observation when 
the determination is made that the shutdown zones are clear of marine 
mammals;
     The USCG must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a 30-second waiting 
period, then two subsequent reduced-energy strike sets. A soft start 
must be implemented at the start of each day's impact pile driving and 
at any time following cessation of impact pile driving for a period of 
30 minutes or longer; and
     If a marine mammal is observed entering or within the 
shutdown zones indicated in table 13, pile driving and DTH must be 
delayed or halted. If pile driving is delayed or halted due to the 
presence of a marine mammal, the activity may not commence or resume 
until either the animal has voluntarily exited and been visually 
confirmed beyond the shutdown zone (table 13) or 15 minutes have passed 
without re-detection of the animal.
    As proposed by the applicant, in-water activities will take place 
only between civil dawn and civil dusk (generally 30 minutes after 
sunrise and up to 45 minutes before sunset), and work may not begin 
without sufficient daylight to conduct pre-activity monitoring, and may 
extend up to 3 hours past sunset, as needed to either completely remove 
an in-process pile or to embed a new pile far enough to safely leave 
piles in place until work can resume the next day; during conditions 
with a Beaufort Sea State of four or less; and when the entire shutdown 
zones are visible.

Protected Species Observers

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

Pre- 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 will observe the shutdown and 
monitoring zones for a period of 30 minutes. The shutdown zone will 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 listed in table 9, pile driving activity will be 
delayed or halted. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones will commence. A 
determination that the shutdown zone is clear must be made during a 
period of good visibility (i.e., the entire shutdown zone and 
surrounding waters must be visible to the naked eye).

Soft-Start Procedures for Impact Driving

    Soft-start procedures provide additional protection to marine 
mammals by providing warning and/or giving marine mammals a chance to 
leave the area prior to the hammer operating at full capacity. If 
impact pile driving is necessary to achieve required tip elevation, the 
USCG is required to provide an initial set of three strikes from the 
hammer at reduced energy, followed by a 30-second waiting period, then 
two subsequent reduced-energy strike sets. Soft-start must be 
implemented at the start of each day's impact pile driving and at any 
time following cessation of impact pile driving for a period of 30 
minutes or longer.

Shutdown Zones

    The USCG must establish shutdown 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 mammal (or in anticipation of an animal entering the defined 
area). Shutdown zones are based upon the Level A harassment thresholds 
for each pile size/type and driving method where applicable, as shown 
in table 13. During all in-water piling activities, the USCG plans to 
implement a minimum 30-m shutdown zone, larger than NMFS' typical 
requirement of a minimum 10-m shutdown zone, with the addition of 
larger zones during DTH. These distances exceed the estimated Level A 
harassment isopleths described in tables 8 and 9. Adherence to this 
expanded shutdown zone will reduce the potential for the take of marine 
mammals by Level A harassment but, due to the large zone sizes and 
small, inconspicuous nature of five species (Steller sea lion, Pacific 
white-sided dolphin (Moorings Seward only), harbor seal, harbor 
porpoise, Dall's porpoise), the potential for Level A harassment cannot 
be completely avoided. If a marine

[[Page 104101]]

mammal is observed entering, or detected within, a shutdown zone during 
pile driving activity, the activity must be stopped until there is 
visual confirmation that the animal has left the zone or the animal is 
not sighted for a period of 15 minutes. Shutdown zones for each 
activity type are shown in table 13.
    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 will continue and PSOs will document the animal's presence 
within the estimated harassment zone.

                                                      Table 13--Shutdown Zones and Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                              Level B         Level B
                                                           Shutdown     Shutdown     Shutdown     Shutdown     Shutdown     harassment      harassment
                        Activity                           zone (m)     zone (m)     zone (m)     zone (m)     zone (m)     zone (m) at     zone (m) at
                                                            for LF       for HF      for VHF       for PW       for OW        Seward           Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile extraction..............................           30           30           30           30           30           4,645           6,310
Impact drive plastic pile..............................           30           30           30           30           30             N/A               5
Impact drive timber pile...............................           30           30           30           30           30             N/A              50
DTH (Impulsive component) concrete pile................        1,955           85        2,325        1,050           85          39,815          39,815
Vibratory concrete pile settling.......................           30           30           30           30           30           7,360           7,360
Impact drive concrete pile proofing....................           30           30           30           30           30             545             545
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Level A (AUD INJ onset) harassment will only potentially result from DTH rock socket drilling activities that will generate underwater noise in
  exceedance of Level A harassment thresholds for all marine mammal hearing groups beyond the 30-m shutdown zone that will be implemented for all in-
  water activities. Therefore, larger shutdown zones will be implemented during DTH activities and at least two additional PSOs will be assigned to a
  captained vessel at one or more monitoring locations that provide full views of the shutdown zones and as much of the monitoring zones as possible.

    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the planned 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.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
conditions in this section and this IHA. Marine mammal monitoring 
during pile driving activities would be conducted by up to five PSOs 
meeting NMFS' standards and in a manner consistent with the following:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
     At least one PSO would have prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
     Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field), or training 
for prior experience performing the duties of a PSO during construction 
activity pursuant to a NMFS-issued incidental take authorization;
     A team of three PSOs (up to five PSOs) at up to three 
locations (including two PSOs on a captained vessel in the case of a 
five-member team) will conduct the marine protected species monitoring 
depending on the activity and size of the relevant shutdown and 
monitoring zones;
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience performing the duties of a PSO 
during construction activity pursuant to a NMFS-issued incidental take 
authorization;
     For activities with monitoring zones beyond the visual 
range of a single PSO (i.e., DTH), additional monitoring locations or 
the use of a vessel with captain and up to three other PSOs (depending 
on size of the monitoring zones) will conduct monitoring; and
     PSOs must be approved by NMFS prior to beginning any 
activity subject to the IHA.
    PSOs should have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and

[[Page 104102]]

times when in-water construction activities were conducted; dates, 
times, and reason for implementation of mitigation (or why mitigation 
was not implemented when required); and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    For all pile driving activities, at least one PSO must be stationed 
at the best possible vantage point to monitor the shutdown zones and as 
much of the Level B harassment zones as possible. A team of three or 
five PSOs at up to three locations (including two PSOs on a captained 
vessel in the case of a five-member team) would conduct marine mammal 
monitoring depending on the activity and size of monitoring zones. PSOs 
would be equipped with high quality binoculars for monitoring and 
radios or cells phones for maintaining contact with work crews. 
Monitoring would be conducted 30 minutes before, during, and 30 minutes 
after all in-water construction activities. In addition, PSOs would 
record all incidents of marine mammal occurrence, regardless of 
distance from activity, and would document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities for each IHA, or 60 days prior to a requested date of 
issuance from any future IHAs for projects at the same location, 
whichever comes first. The report will include an overall description 
of work completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. The USCG must submit all PSO data 
electronically in a format that can be queried such as a spreadsheet or 
database (i.e., digital images of data sheets are not sufficient). 
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., impact, vibratory, DTH) and the total 
equipment duration for vibratory removal for each pile or total number 
of strikes for each pile (impact driving);
     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:
    [cir] Name of PSO who sighted the animal(s) and PSO location and 
activity at the time of sighting;
    [cir] Time of sighting;
    [cir] Identification of the animal(s) (e.g., genus/species, lowest 
possible taxonomic level, or unidentifiable), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    [cir] 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);
    [cir] Estimated number of animals (min/max/best estimate);
    [cir] Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, sex class, etc.);
    [cir] Animal's closest point of approach and estimated time spent 
within the harassment zone; and
    [cir] 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 and shutdown zones; by species; and
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensured, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
reports will constitute the final reports. 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 event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the USCG must immediately 
cease the specified activities and report the incident to the Office of 
Protected Resources ([email protected] and 
[email protected]), NMFS, and to the Alaska Regional Stranding 
Coordinator as soon as feasible. If the death or injury was clearly 
caused by the specified activity, the USCG must immediately cease the 
specified activities until NMFS is able to review the circumstances of 
the incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS. The 
report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29,

[[Page 104103]]

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 1 at both project locations, given that the 
anticipated effects of this activity on these different marine mammal 
stocks are expected to be similar in Seward and Sitka. 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 DTH activities associated with the specified 
activities, as described 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 only for all species 
other than the Steller sea lion, harbor seal, Pacific white-sided 
dolphin, harbor porpoise, and Dall's porpoise from underwater sounds 
generated from pile driving and DTH. Potential takes could occur if 
individual marine mammals are present in the ensonified areas when pile 
driving or DTH is occurring.
    No serious injury or mortality would be expected, even in the 
absence of required mitigation measures, given the nature of the 
activities. For all species other than Steller sea lion, harbor seal, 
Pacific white-sided dolphin, harbor porpoise, and Dall's porpoise, no 
Level A harassment is anticipated due to the confined nature of the 
facilities, ability to position PSOs at stations from which they can 
observe the entire shutdown zones, and the high visibility of the 
species expected to be present at each site. The potential for injury 
is small for mid- and low-frequency cetaceans and sea lions, and is 
expected to be essentially eliminated through implementation of the 
planned mitigation measures--soft start (for impact driving), and 
shutdown zones. Further, no take by Level A harassment is anticipated 
for killer whales, humpback whales, gray whales, fin whales, or minke 
whales due to the application of planned mitigation measures and the 
small Level A harassment zones (for killer whales only). The potential 
for harassment will be minimized through the construction method and 
the implementation of the planned mitigation measures (see Mitigation 
section).
    Take by Level A harassment is authorized for Steller sea lion, 
harbor seal, Pacific white-sided dolphin, harbor porpoise, and Dall's 
porpoise. Due to their inconspicuous nature, it is possible individuals 
of these species could enter the Level A harassment zone undetected and 
remain within that zone for a duration long enough to incur AUD INJ. 
Any take by Level A harassment is expected to arise from, at most, a 
small degree of AUD INJ (i.e., minor degradation of hearing 
capabilities within regions of hearing that align most completely with 
the energy produced by impact pile driving such as the low-frequency 
region below 2 kHz), not severe hearing impairment or impairment within 
the ranges of greatest hearing sensitivity. Animals would need to be 
exposed to higher levels and/or longer duration than are expected to 
occur here in order to incur any more than a small degree of AUD INJ.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect any of the species or stocks 
through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Level A harassment would be very small amounts and of low 
degree;
     Level B harassment would be primarily in the form of 
behavioral disturbance, resulting in avoidance of the project areas 
around where piling is occurring, with some low-level TTS that may 
limit the detection of acoustic cues for relatively brief amounts of 
time in relatively confined footprints of the activities;
     The ensonified areas are very small relative to the 
overall habitat ranges of all species and stocks, and would not 
adversely affect ESA-designated critical habitat for any species or any 
areas of known biological importance;
     The amount of take authorized accounts for no more than, 
at most, 3 percent of any stock that may occur in the project areas;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and
     The implementation of mitigation measures to minimize the 
number of marine mammals exposed to injurious levels of sound and 
ensure take by Level A harassment is, at most, a small degree of AUD 
INJ.
    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 planned monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the 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.
    The amount of take NMFS has authorized is below one-third of the 
estimated stock abundance of all species and stocks (take of 
individuals is less than 3 percent of the abundance of the affected 
stocks at Moorings Seward and Moorings Sitka; see tables 11 and 12). 
This is likely a conservative estimate because it assumes all takes are 
of different individual animals, which is likely not the case. Some 
individuals may return multiple times in a day but PSOs would count 
them as separate takes if they cannot be individually identified.
    There are no valid abundance estimates available for humpback 
whales (Mexico-North Pacific stock), fin whales (Northeast Pacific 
stock), minke whales (Alaska stock), Dall's porpoises (Alaska stock), 
and harbor porpoises (Yakutat/Southeast Alaska Offshore Waters stock). 
There is no recent stock abundance estimate for the Mexico-North 
Pacific stock of humpback whale and the minimum population is 
considered unknown (Young et al., 2023). There are 2 minimum population 
estimates for this stock that are over 15 years old: 2,241 
(Mart[iacute]nez-Aguilar, 2011) and 766 (Wade, 2021). Using either of 
these estimates, the three takes by Level B harassment authorized (two 
at Moorings Seward, one at Moorings Sitka) represent small numbers of 
the stock. Muto et al. (2021) estimate the minimum stock size for the 
Northeast Pacific stock of fin whale for the areas

[[Page 104104]]

surveyed is 2,554 individuals. Therefore, the three takes by Level B 
harassment of this stock at Moorings Seward represent small numbers of 
this stock. There is also no current abundance estimate of the Alaska 
stock of minke whale but over 2,000 individuals were documented in 
areas recently surveyed (Muto et al., 2021). Therefore, the 22 takes by 
Level B harassment at Moorings Sitka represent small numbers of this 
stock, even if each take occurred to a new individual.
    The most recent stock abundance estimate of the Alaska stock of 
Dall's porpoise was 83,400 animals and, although the estimate is more 
than 8 years old, it is unlikely this stock has drastically declined 
since that time. Therefore, the 72 takes authorized, 15 by Level A and 
57 by Level B harassment (6 total at Moorings Seward, 66 total at 
Moorings Sitka), represent small numbers of this stock. A current 
stock-wide abundance estimate for the Yakutat/Southeast Alaska Offshore 
Waters stock of harbor porpoises in offshore waters (which includes 
Moorings Sitka) is not available (Young et al., 2023). However, Muto et 
al. (2021) estimate the minimum stock size for the areas surveyed is 
1,057 individuals. Therefore, the 35 takes authorized at Moorings Sitka 
(3 by Level A harassment, 32 by Level B harassment) represent small 
numbers of this stock.
    Based on the analysis contained herein of the activity (including 
the planned mitigation and monitoring measures) and the anticipated 
take of marine mammals, NMFS 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.
    There are two species of marine mammals analyzed herein that have 
been taken as part of subsistence harvests in Resurrection Bay and 
southeast Alaska: Steller sea lion and harbor seal. The most recent 
data on subsistence-harvested marine mammals near Seward is of harbor 
seals in 2002, and the most recent data near Sitka is of both harbor 
seals and Steller sea lions in 2013 (ADFG, 2013). The most recent 
subsistence hunt survey data available indicated approximately 11 
percent of Sitka households used subsistence-caught marine mammals 
(Sill and Koster, 2013) and no data is available since that time.
    The project is not likely to adversely impact the availability of 
any marine mammal species or stocks that are commonly used for 
subsistence purposes or impact subsistence harvest of marine mammals in 
the region. Although the activities are located in regions where 
subsistence harvests have occurred historically, subsistence harvest of 
marine mammals is rare in the project areas and local subsistence users 
have not expressed concern about this project. Both locations are 
adjacent to heavily traveled industrialized waterways and all project 
activities will take place within closed and secured waterfronts where 
subsistence activities do not generally occur. The project also will 
not have an adverse impact on the availability of marine mammals for 
subsistence use at locations farther away, where the construction 
activities are not expected to take place. Some minor, short-term 
harassment of Steller sea lions and harbor seals could occur, but any 
effects on subsistence harvest activities in the project areas will be 
minimal, and not have an adverse impact.
    Based on the description of the specified activity and the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the planned mitigation and 
monitoring measures, NMFS has determined that there will not be an 
unmitigable adverse impact on subsistence uses from the USCG's 
activities.

Endangered Species Act

    Section 7(a)(2) of the ESA of 1973 (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.
    There are three marine mammal species (Western DPS Steller sea 
lion, Mexico-North Pacific stock of humpback whale, and the Northeast 
Pacific stock of fin whale) with confirmed occurrence in the project 
areas that are listed as endangered under the ESA. The NMFS Alaska 
Regional Office Protected Resources Division issued a Biological 
Opinion on December 3, 2024, under section 7 of the ESA, on the 
issuance of an IHA to the USCG under section 101(a)(5)(D) of the MMPA 
by the NMFS Permits and Conservation Division. The Biological Opinion 
concluded that the proposed action is not likely to jeopardize the 
continued existence of Western DPS Steller sea lion, Mexico DPS of 
humpback whale, the Western North Pacific DPS of humpback whale, or the 
Northeast Pacific stock of fin whale, and is not likely to destroy or 
adversely modify critical habitat for Western DPS Steller sea lion, 
Mexico DPS of humpback whale, the Western North Pacific DPS of humpback 
whale, or the Northeast Pacific stock of fin whale.

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 determined that the 
issuance of these IHAs qualify to be categorically excluded from 
further NEPA review.

Authorization

    NMFS has issued 2 IHAs to the USCG for the potential harassment of 
small numbers of 11 marine mammal species incidental to construction of 
FRC homeporting docks in Seward and Sitka, Alaska, that includes the 
previously explained mitigation, monitoring, and reporting 
requirements.

[[Page 104105]]

    Dated: December 17, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2024-30455 Filed 12-19-24; 8:45 am]
BILLING CODE 3510-22-P
```