`[Federal Register Volume 89, Number 226 (Friday, November 22, 2024)]
[Notices]
[Pages 92627-92644]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-27342]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XE193]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Gary Paxton Industrial Park Vessel 
Haulout Project in Sitka, Alaska

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
City and Borough of Sitka (CBS) to incidentally harass marine mammals 
during construction activities associated with Gary Paxton Industrial 
Park Vessel Haulout Project in Sawmill Cove in Sitka, Alaska.

DATES: This authorization is effective one year from the date of 
issuance.

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: Kate Fleming, Office of Protected 
Resources (OPR), NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

Summary of Request

    On January 18, 2024, NMFS received a request from CBS for an IHA to 
take

[[Page 92628]]

marine mammals incidental to construction associated with the Gary 
Paxton Industrial Park Vessel Haulout Project in Sawmill Cove in Sitka, 
Alaska. Following NMFS' review of the application, CBS submitted a 
revised version on March 20, 2024, and another on April 27, 2024. The 
application was deemed adequate and complete on May 20, 2024. CBS's 
request is for take of nine species of marine mammals by Level B 
harassment and, for a subset of those species, by Level A harassment. 
Neither CBS nor NMFS expect serious injury or mortality to result from 
this activity and, therefore, an IHA is appropriate.
    NMFS previously issued an IHA to CBS for similar work (82 FR 47717, 
October 13, 2017). CBS complied with all the requirements (e.g., 
mitigation, monitoring, and reporting) of the previous IHA, and 
information regarding their monitoring results may be found in the 
Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat section.
    This IHA covers one year of a larger project; CBS intends to 
request a future take authorization for subsequent facets of the 
project. In year 1, construction of the following elements are planned: 
150-ton capacity vessel haulout piers, expanded uplands including 
stormwater collection and treatment, and a vessel washdown pad. The 
larger multi-year project involves construction of a queuing float, 
approach dock and gangway, a pile-supported deck area, vessel haulout 
ramp, an uplands shipyard, and pile anodes. While not planned to be 
constructed as part of this project, CBS's goal is to eventually 
construct additional haulout piers to accommodate removal of vessels up 
to 300 tons.

Description of Specified Activity

Overview

    The CBS is constructing a vessel haulout facility at Gary Paxton 
Industrial Park in Sawmill Cove in Sitka, Alaska. Across 62 
construction days across a 1-year period, CBS plans to ibratory and 
impact install 36-in steel haulout pier support piles (both vertical 
and battered), vibratory install 24-in steel fender piles, and 
vibratory install and remove 24-in steel temporary template pipe piles. 
These methods of pile driving would introduce underwater sounds that 
may result in take, by Level A and Level B harassment, of marine 
mammals.
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed IHA (89 FR 
56317, July 9, 2024). Since that time, no changes have been made to the 
planned activities. Therefore, a detailed description is not provided 
here. Please refer to the Federal Register notice for the description 
of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to CBS was published in 
the Federal Register on July 9, 2024 (89 FR 56317). That notice 
described, in detail, CBS'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 
authorization described therein, our analyses, the proposed 
authorization, and any other aspect of the notice of proposed IHA, and 
requested that interested persons submit relevant information, 
suggestions, and comments. During the 30-day public comment period, 
NMFS did not receive any substantive public comments.

Changes From the Proposed IHA to Final IHA

    On May 3, 2024, NMFS published (89 FR 36762) and solicited public 
comment on its draft updated Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing Underwater and 
In-Air Criteria for Onset of Auditory Injury and Temporary Threshold 
Shifts (Version 3.0) (2024 Technical Guidance), which includes updated 
thresholds and weighting functions to inform auditory injury (AUD INJ) 
estimates. The public comment period ended on June 17th, 2024, and the 
2024 Technical Guidance was finalized on October 24, 2024. The 2024 
Technical Guidance represents the best available science and has been 
incorporated into the analysis in this final IHA. The relevant updated 
hearing group names, thresholds, and weighting functions may be found 
in the executive summary of the 2024 Technical Guidance. The resultant 
updated isopleths for this project are presented in table 9 of the 
Estimated Take of Marine Mammals section. There were no substantive 
changes to Level A harassment isopleths for low frequency cetaceans 
(they increased slightly during vibratory activities and decreased 
slightly during impact pile driving). However, for high-frequency 
cetaceans (categorized as mid-frequency cetaceans prior to application 
of the 2024 Technical Guidance), phocids, and otariids, Level A 
harassment isopleths increased substantially during all pile driving 
activities. Additionally, for very high frequency cetaceans 
(categorized as high frequency cetaceans prior to application of the 
2024 Technical Guidance), Level A harassment isopleths decreased 
slightly during vibratory activities and substantially during impact 
pile driving.
    Necessary modifications to mitigation zones are presented in table 
12 in the Mitigation section. In cases where the Level A harassment 
zones were smaller, the mitigation zones were not adjusted. In cases 
where the Level A harassment zones were larger, the mitigation zones 
were increased to either meet the Level A harassment isopleth, or to 
whatever distance was established after consideration of practicability 
and observability.
    For all species, the total number of takes proposed for 
authorization is equal to the total number of takes authorized by Level 
A and Level B harassment; for some species, estimates of take by Level 
A harassment were updated based on the analysis under the 2024 Updated 
Technical Guidance. Updated take numbers are presented in table 10.
    Specifically, species with increased take by Level A harassment 
include Pacific white-sided dolphin (Lagenorhynchus obliquidens), 
harbor porpoise (Phocoena phocoena), Steller sea lion (Eumetopias 
jubatus), California sea lion (Zalophus californianus), Northern fur 
seal (Callorhinus ursinus), and harbor seal (Phoca vitulina). Take by 
Level A harassment increased from 5 from 6 for harbor porpoise, 89 to 
240 Steller sea lion (88 to 237 Eastern Distinct Population Segment 
(DPS); 1 to 3 Western DPS), and 34 to 53 for harbor seal. For Pacific 
white-sided dolphin, California sea lion, and Northern fur seal, no 
take by Level A harassment was proposed for authorization; however, 
based on our re-analysis under the 2024 Technical Guidance, we have 
authorized up to 4 takes by Level A harassment for Pacific white-sided 
dolphin. For both California sea lion and Northern fur seal, three 
takes by either Level A or Level B harassment have been authorized. The 
negligible impact analyses has been updated to consider the increases 
to take by Level A harassment for Pacific white-sided dolphin, harbor 
porpoise, Steller sea lion, California sea lion, Northern fur seal, and 
harbor seal.
    NMFS also corrected a number of typographical errors. In table 6 of 
the proposed IHA Federal Register notice (89 FR 56317, July 9, 2024), 
the total number of 24-inch (-in) steel piles to be vibratory installed 
and removed via vibratory installation was erroneously listed as 2 
instead of 4 (permanent piles) and 2 instead of 8 (template piles).

[[Page 92629]]

Additionally, the total number of 36-in steel piles to be installed via 
impact pile driving was erroneously listed as 4 instead of 2 (support 
piles) and 8 instead of 2 (batter piles). These values have been 
corrected in table 5 of this notice. There are no changes to Level A 
and Level B isopleths or associated take estimates or mitigation 
measures associated with these typographical corrections.
    Next, in table 8 of the proposed IHA Federal Register notice (89 FR 
56317, July 9, 2024), the proposed take as a percentage of stock was 
incorrectly reported as <1 instead of 2.2 for the Hawai'i stock of 
humpback whale and as 14.2 instead of 2.3 for the Eastern North Pacific 
Stock of killer whale. These errors have been corrected in table 10 and 
do not affect the small numbers of negligible impact analysis and 
determination.
    Finally, in the small numbers section of the proposed IHA Federal 
Register notice (89 FR 56317, July 9, 2024), the harbor porpoise take 
estimates proposed for authorization were erroneously listed as 16 
takes by Level B harassment and 6 takes by Level A harassment instead 
of 17 takes by Level B harassment and 5 takes by Level A harassment. 
Take estimates were correctly listed elsewhere in the notice.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of CBS's 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 this activity and summarizes information related to the 
population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. PBR is defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS' SARs). While no 
serious injury or mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species or 
stocks and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Alaska and 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.

                     Table 1--Marine Mammal Species \1\ Likely To Occur Near the Project Area That May Be Taken by CBS's 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\               S1 \4\
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                                                 Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray Whale......................  Eschrichtius robustus..  Eastern N Pacific......  -, -, N             26,960 (0.05, 25,849,         801        131
                                                                                                             2016).
Family Balaenopteridae (rorquals):
    Humpback Whale..................  Megaptera novaeangliae.  Hawai[revaps]i.........  -, -, N             11,278 (0.56, 7,265,          127      27.09
                                                                                                             2020).
                                                               Mexico-North Pacific...  T, D, Y             N/A (N/A, N/A, 2006) \        UND       0.57
                                                                                                             5\.
Family Delphinidae:
    Killer Whale....................  Orcinus orca...........  Eastern North Pacific    -, -, N             1,920 (N/A, 1,920,             19        1.3
                                                                Alaska Resident.                             2019) \6\.
                                                               Eastern North Pacific    -, -, N             587 (N/A, 587, 2012)          5.9        0.8
                                                                Gulf of Alaska,                              \6\.
                                                                Aleutian Islands and
                                                                Bering Sea Transient.
                                                               Eastern Northern         -, -, N             302 (N/A, 302, 2018)          2.2        0.2
                                                                Pacific Northern                             \6\.
                                                                Resident.
                                                               West Coast Transient...  -, -, N             349 (N/A, 349, 2018)          3.5        0.4
                                                                                                             \6\.
    Pacific White-Sided Dolphin.....  Lagenorhynchus           N Pacific..............  -, -, N             26,880 (N/A, N/A,             UND          0
                                       obliquidens.                                                          1990).
Family Phocoenidae (porpoises):
    Harbor Porpoise.................  Phocoena phocoena......  Yakutat/Southeast        -, -, N             N/A (N/A, N/A, 1997)          UND       22.2
                                                                Alaska Offshore Waters.                      \7\.
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                                                               Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    CA Sea Lion.....................  Zalophus californianus.  U.S....................  -, -, N             257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
    Northern Fur Seal...............  Callorhinus ursinus....  Eastern Pacific........  -, D, Y             626,618 (0.2, 530,376,     11,403        373
                                                                                                             2019).
    Steller Sea Lion................  Eumetopias jubatus.....  Western................  E, D, Y             49,837 (N/A, 49,837,          299        267
                                                                                                             2022) \8\.
                                                               Eastern................  -, -, N             36,308 (N/A, 36,308,        2,178       93.2
                                                                                                             2022) \9\.
Family Phocidae (earless seals):

[[Page 92630]]

 
    Harbor Seal.....................  Phoca vitulina.........  Sitka/Chatham Strait...  -, -, N             13,289 (N/A, 11,883,          356         77
                                                                                                             2015).
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies; Committee on Taxonomy, 2022).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal 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. In some cases, CV is not applicable [explain if this is the case]
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ Abundance estimates are based upon data collected more than 8 years ago and, therefore, current estimates are considered unknown.
\6\ Nest is based upon counts of individuals identified from photo-ID catalogs.
\7\ New stock split from Southeast Alaska stock.
\8\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the United
  States only. The overall Nmin is 73,211 and overall PBR is 439.
\9\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the United
  States only.

    A detailed description of the species likely to be affected by 
CBS's GPIP vessel haulout 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 56317; July 9, 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 to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Subsequently, NMFS (2018, 2024) 
described generalized hearing ranges for these marine mammal hearing 
groups. Generalized hearing ranges were chosen based on the 
approximately 65-decibel (dB) threshold from the normalized composite 
audiograms, with the exception for lower limits for low-frequency 
cetaceans where the lower bound was deemed to be biologically 
implausible and the lower bound from Southall et al. (2007) retained. 
Note that between the proposed FRN (89 FR 56317, July 9, 2024) and the 
issuance of the final IHA, NMFS' 2024 Technical Guidance was finalized 
(89 FR 84872, 24 October 2024) and has been incorporated into this 
analysis. The marine mammal hearing groups and their associated hearing 
ranges included in the proposed FRN (89 FR 56317, July 9, 2024) are 
provided in table 2. The re-named marine mammal hearing groups that 
have been incorporated into this final IHA are presented in table 3. 
The references, analysis, and methodology used in the development of 
the thresholds are described in the 2024 Technical Guidance, which may 
be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                  Table 2--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen  7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans          150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true   275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchids, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)    50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)   60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65-dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).


[[Page 92631]]


                  Table 3--Marine Mammal Hearing Groups
                               [NMFS 2024]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen  7 Hz to 36 kHz.
 whales).
High-frequency (HF) cetaceans         150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
Very High-frequency (VHF) cetaceans   200 Hz to 165 kHz.
 (true porpoises, Kogia, river
 dolphins, Cephalorhynchid,
 Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW) (underwater)    40 Hz to 90 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)   60 Hz to 68 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges may not be as broad. Generalized hearing range
  chosen based on ~65 dB threshold from composite audiogram, previous
  analysis in NMFS 2018, and/or data from Southall et al. 2007; Southall
  et al. 2019. Additionally, animals are able to detect very loud sounds
  above and below that ``generalized'' hearing range.

    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 CBS's construction activities 
have the potential to result in the harassment of marine mammals in the 
vicinity of the project area. The notice of proposed IHA (89 FR 56317; 
July 9, 2024) included a discussion of the effects of anthropogenic 
noise on marine mammals and the potential effects of underwater noise 
from CBS's construction 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 56317; July 9, 2024).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, 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 are primarily by Level B harassment, as use of the 
acoustic sources (i.e., pile driving) 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, for 
all hearing groups because, after applying the 2024 Technical Guidance, 
the predicted AUD INJ zones have increased such that Protected Species 
Observers (PSO) may be unable to observe most of these species during 
impact pile driving. The 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 take estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur AUD INJ of some degree (equated to 
Level A harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources. Generally speaking, Level B harassment take 
estimates based on these behavioral harassment thresholds are expected 
to include any likely takes by 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

[[Page 92632]]

communication, predators, prey) may result in changes in behavior 
patterns that would not otherwise occur.
    CBS's activity includes the use of continuous (vibratory pile 
driving) and impulsive (impact pile driving) sources, and therefore the 
RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are applicable.
    Level A Harassment--NMFS' 2024 Technical Guidance (NMFS, 2024) 
identifies dual criteria to assess AUD INJ (Level A harassment) to 5 
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). Note that between the proposed FRN (89 FR 
56317, July 9, 2024) and the issuance of the final IHA, NMFS' 2024 
Technical Guidance was finalized (89 FR 84872, 24 October 2024) and has 
been incorporated into this analysis. CBS's activity includes the use 
of impulsive (impact pile driving) and non-impulsive (continuous pile 
driving) sources.
    The thresholds identifying the onset of Permanent Threshold Shift 
(PTS) based on 2018 Technical Guidance and included in the proposed FRN 
(89 FR 56317, July 9, 2024) are provided in table 4. The references, 
analysis, and methodology used in the development of the thresholds 
used in the proposed IHA are described in NMFS' 2018 Technical 
Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance. The updated thresholds, which identify the Onset of AUD INJ 
based on the 2024 Technical Guidance, have been incorporated in this 
final IHA are presented in table 5. The references, analysis, and 
methodology used in the development of the thresholds are described in 
the 2024 Technical Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance. NMFS defines AUD INJ as ``damage to the 
inner ear that can result in destruction of tissue . . . which may or 
may not result in PTS'' (NMFS 2024). NMFS defined PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2024).

                Table 4--Thresholds Identifying the Onset of PTS based on 2018 Technical Guidance
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to reflect ANSI standards
  (ANSI, 2013). However, peak sound pressure is defined by ANSI as incorporating frequency weighting, which is
  not the intent for this Technical Guidance. Hence, the subscript ``flat'' is being included to indicate peak
  sound pressure should be flat weighted or unweighted within the generalized hearing range. The subscript
  associated with cumulative sound exposure level thresholds indicates the designated marine mammal auditory
  weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation
  period is 24 hours. The cumulative sound exposure level thresholds could be exceeded in a multitude of ways
  (i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for action proponents
  to indicate the conditions under which these acoustic thresholds will be exceeded.


          Table 5--Thresholds Identifying the Onset of Auditory Injury Based on 2024 Technical Guidance
----------------------------------------------------------------------------------------------------------------
                                                       AUD INJ onset thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Hearing group..........................
Low-Frequency (LF) Cetaceans...........  Cell 1: L0-pk,flat: 222     Cell 2: LE,LF,24h: 197 dB.
                                          dB; LE,LF,24h: 183 dB.
High-Frequency (HF) Cetaceans..........  Cell 3: L0-pk,flat: 230     Cell 4: LE,, HF,24h: 201 dB.
                                          dB; LE,HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans....  Cell 5: L0-pk,flat: 202     Cell 6: LE, VHF,24h: 181 dB.
                                          dB; LE,VHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: L0-pk.flat: 223     Cell 8: LE,PW,24h: 195 dB.
                                          dB; LE,PW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: L0-pk,flat: 230     Cell 10: LE,OW,24h: 199 dB.
                                          dB; LE,OW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating AUD
  INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
  associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
  is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
  hearing range of marine mammals (i.e., 7 Hz to 165 kHz). The subscript associated with cumulative sound
  exposure level thresholds 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 thresholds could be exceeded in a multitude of ways (i.e., varying exposure
  levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the
  conditions under which these thresholds will be exceeded.


[[Page 92633]]

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the planned project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., pile driving and removal).
    The project includes vibratory pile installation and removal, and 
impact pile driving. Source levels for these activities are based on 
reviews of measurements of the same or similar types and dimensions of 
piles available in the literature. Source levels for each pile size and 
activity each year are presented in table 6. Source levels for 
vibratory installation and removal of piles of the same diameter are 
assumed to be the same.

Table 6--Estimates of Mean Underwater Sound Levels * Generated During Vibratory and Impact Pile Installation and
                                             Vibratory Pile Removal
----------------------------------------------------------------------------------------------------------------
     Pile driving method           Pile type      Pile size    dB RMS      dB peak     dB SEL       Reference
----------------------------------------------------------------------------------------------------------------
Impact.......................  Steel Pipe             36-in         193         210         183  Caltrans 2015,
                                Support Pile.                                                     2020.
                               Steel Pipe        ..........  ..........  ..........  ..........  ...............
                                Batter Pile.
Vibratory Installation and     Steel Pipe             36-in         166         N/A         N/A  NMFS 2023
 Extraction.                    Support.                                                          Calculations.
                               Steel Pipe        ..........  ..........  ..........  ..........  ...............
                                Batter.
                               Steel Pipe             24-in         163         N/A         N/A  NMFS 2023
                                Fender.                                                           Calculations
                               Steel Pipe        ..........  ..........  ..........  ..........  ...............
                                Template.
----------------------------------------------------------------------------------------------------------------
Note: dB peak = peak sound level; rms = root mean square; SEL = sound exposure level.
* All sound levels are referenced at 10 m.

    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

TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    Absent site-specific acoustical monitoring with differing measured 
TL, a practical spreading value of 15 is used as the TL coefficient in 
the above formula. Site-specific TL data for the Sitka Sound are not 
available; therefore, the default coefficient of 15 is used to 
determine the distances to the Level A harassment and Level B 
harassment thresholds.
    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 2024 Technical Guidance that can be 
used to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources such as pile driving, the optional User Spreadsheet 
tool predicts the distance at which, if a marine mammal remained at 
that distance for the duration of the activity, it would be expected to 
incur AUD INJ, which includes, but is not limited to, PTS. Inputs used 
in the optional User Spreadsheet tool, and the resulting estimated 
isopleths, are reported below. Table 8 provides the calculated Level A 
isopleths that are based on the 2018 Technical Guidance, which were 
presented in the proposed FRN (89 FR 56317, July 9, 2024) while table 9 
provides the updated Level A isopleths using the 2024 Technical 
Guidance.

                                        Table 7--User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                                         Vibratory                               Impact
                                   -----------------------------------------------------------------------------
                                       36-in                                               36-in
                                      haulout       36-in        24-in        24-in       haulout       36-in
                                        pier       haulout      haulout      template       pier       haulout
                                      support    pier batter  pier fender      pile       support    pier batter
                                        pile         pile         pile                      pile         pile
----------------------------------------------------------------------------------------------------------------
                                                 Installation              Installatio
                                                                                  n or
                                                                               removal        Installation
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used..............              A.1) Vibratory pile driving
                                    E.1) Impact pile driving
                                   -----------------------------------------------------------------------------
Source Level (SPL)................           166 RMS
                                             163 RMS
                                             183 SEL
                                   -----------------------------------------------------------------------------
Transmission Loss Coefficient.....                                       15
                                   -----------------------------------------------------------------------------
Weighting Factor Adjustment (kHz).                          2.5
                                                2
                                   -----------------------------------------------------------------------------
Activity Duration per day                    60          120           30           20  ...........  ...........
 (minutes)........................

[[Page 92634]]

 
Number of strikes per pile........  ...........  ...........  ...........  ...........        2,000        3,000
                                   -----------------------------------------------------------------------------
Number of piles per day...........              2                       4            8              2
                                   -----------------------------------------------------------------------------
Distance of sound pressure level
 measurement......................                                       10
----------------------------------------------------------------------------------------------------------------


        Table 8--Level A Harassment and Level B Harassment Isopleths and Associated Areas From Vibratory and Impact Pile Driving and Vibratory Removal, Using the 2018 Technical Guidance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Level A harassment: isopleths (m), areas (km\2\)                                   Level B harassment:
          Pile size/type                  Method        -------------------------------------------------------------------------------------------------------------------  isopleth (m), areas
                                                                   LF                     MF                     HF                     PW                     OW                  (km\2\)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Haulout Pier Support Pile
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile............  Vibratory             23.4, (0.006)          2.1, (0.001)           34.5, (0.009)          14.2, (0.004)          1.0, (0.001)           11,659, (9.41)
                                    Installation.
                                   Impact Installation.  2,516, (3.13)          89.5, (0.022)          2,997, (3.64)          1,347, (1.49)          98, (0.024)            1,585, (1.94)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Haulout Pier Batter Pile
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile............  Vibratory             37.1, (0.010)          3.3, (0.003)           54.8, (0.013)          22.5, (0.006)          1.6, (0.001)           11,659, (9.41)
                                    Installation.
                                   Impact Installation.  3,297, (3.97)          117.3, (0.029)         3,928, (4.64)          1,765, (2.24)          128, (0.032)           1,585, (1.94)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Haulout Pier Fender Pile
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile............  Vibratory             14.7, (0.004)          1.3, (0.001)           21.8, (0.006)          9.0, (0.003)           0.6, (0.001)           7,356, (7.61)
                                    Installation.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Template Pile
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile............  Vibratory             17.9, (0.005)          1.6, (0.001)           26.4, (0.008)          10.9, (0.003)          0.8, (0.001)           7,356, (7.61)
                                    Installation and
                                    Removal.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


 Table 9--Level A Harassment and Level B Harassment Isopleths and Associated Areas * From Vibratory and Impact Pile Driving and Vibratory Removal, Using
                                                               the 2024 Technical Guidance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Level A harassment: isopleths (m), areas (km\2\)                        Level B
                                                  ------------------------------------------------------------------------------------    harassment:
        Pile size/type                Method                                                                                             isopleth (m),
                                                        LF         HF \1\          VHF \2\               PW                 OW           areas (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Support Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile.........  Vibratory                 31.5         12.1  25.8                40.6               13.7               11,659, (9.41)
                                 Installation.
                                Impact                   2,507        319.9  3,880, (4.59)       2,227.3, (2.86)    830.3, (0.62)      1,585, (1.94)
                                 Installation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Batter Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile.........  Vibratory                 50.1         19.2  40.9                64.4               21.7               11,659, (9.41)
                                 Installation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Impact                 3,285.4        419.2  5,084.2 (5.73)      2,918.6 (3.55)     1,087.9 (1.01)     1,585, (1.94)
                                 Installation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Fender Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile.........  Vibratory                 19.9          7.6  16.3                25.6               8.6                7,356, (7.61)
                                 Installation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Template Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile.........  Vibratory                 24.1          9.3  19.7                31.0               10.4               7,356, (7.61)
                                 Installation and
                                 Removal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Level A harassment areas (km\2\) have been presented only in cases where they are necessary to calculate updates to take by Level A harassment based
  on the 2024 Technical Guidance and methodology used in the Proposed IHA (89 FR 56317, July 9, 2024). In cases where the shutdown zone meets or exceeds
  the Level A harassment isopleth, take by Level A harassment was not reanalyzed.
\1\ Species that were considered Mid-Frequency cetaceans under the NMFS 2018 Technical Guidance are now considered High Frequency cetaceans.
\2\ Species that were considered High-Frequency cetaceans under the NMFS 2018 Technical Guidance are now considered Very High Frequency cetaceans.


[[Page 92635]]

Marine Mammal Occurrence and Take Estimation

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations.
    Additionally, we describe how the occurrence information is 
synthesized to produce a quantitative estimate of the take that is 
reasonably likely to occur and authorized. Available information 
regarding marine mammal occurrence in the vicinity of the project area 
includes site-specific and nearby survey information and historic data 
sets. Prior data sets consulted included: (1) PSO monitoring completed 
at the project site on 8 days between September 20 and 29, 2023 during 
the geotechnical investigation preceding this project (Solstice, 2023), 
(2) PSO monitoring completed at the project site on 22 days between 
October and November 2017 during the Multipurpose Dock Project (TMC, 
2017), (3) PSO monitoring completed at O'Connell Bridge (approximately 
7 km to the east of the project site) on 4 days in June 2019 (CBS, 
2019); (4) Land-based surveys conducted at Sitka's Whale Park completed 
weekly between September and May 1995--2000 (Straley and Pendell 
(2017)); and, (5) data available on the Global Biodiversity Information 
Facility (see CBS's application for further details).
    To estimate take, CBS referred to the above referenced data sets to 
estimate total (Level A and Level B combined) takes per day for each 
species and multiplied this factor by the total number of construction 
days. NMFS finds it more appropriate to describe the take estimate 
inputs according to a daily occurrence probability in which groups per 
day and group size are estimated for each species and multiplied by the 
number of days of each type of pile driving activity. The equation used 
to estimate take by Level B harassment for all species is:

Exposure Estimate = group size x groups per day x days of pile driving 
activity.

    CBS initially planned to implement shutdown zones for mid-frequency 
cetaceans and otariids (except Steller sea lions) that met or exceeded 
the Level A harassment isopleths for all activities. Using the 2018 
Technical Guidance, the calculated Level A harassment zones during 
impact installation of 36-in steel piles, planned to occur on 30 
construction days, exceeded the shutdown zones for phocids, high 
frequency cetaceans, and low frequency cetaceans. After applying the 
2024 Technical Guidance, the calculated Level A harassment zones for 
this activity exceeded the shutdown zones for all species except killer 
whale. The best available abundance estimates for these species cover 
the general region of Sitka Sound and Silver Bay; therefore, we used 
proportional comparisons of predicted harassment areas to estimate 
predicted take by Level A harassment. In the absence of density data, 
best available monitoring data for the general area were used to 
estimate take by Level A harassment. Specifically, to calculate 
estimated take by Level A harassment for all species except California 
sea lion and Northern fur seal, which are expected to be very rare for 
the area) we proportionally compared, by hearing group, the portion of 
the largest Level A harassment area square kilometers (km\2\) that 
exceeds the planned shutdown zone area (km\2\) to the area (km\2\) of 
the largest Level B harassment zone across that pile type (typically 
from vibratory pile driving). This ratio was then multiplied by the 
group size, daily sightings, and number of construction days, according 
to the equation below. For LF cetaceans, there was no meaningful change 
to the calculated Level A harassment isopleths after applying the 2024 
Technical Guidance. For killer whales, the shutdown zone still exceeds 
the calculated Level A harassment isopleths. Therefore, the take 
estimates for these species (LF cetaceans and killer whale) have not 
changed. The estimated take by Level A harassment has been updated for 
all other species to account for larger Level A harassment isopleths 
which exceed the shutdown zone.

Take by Level A harassment = Level A harassment area (km\2\)/maximum 
Level B harassment area (km\2\) x group size x groups per day x days of 
pile driving.

    For Steller sea lions, during impact pile driving of 36-in steel 
pipe piles (batter and support), the shutdown zone will be established 
at 60 meters (m) rather than the larger Level A harassment isopleths 
due to practicability; local monitoring data suggests that Steller sea 
lions frequently occur within close proximity of the project site. The 
method described above did not produce an estimate of take by Level A 
harassment consistent with the best available data for this species at 
the project location. Therefore, recent monitoring data collected at 
this site (Solstice, 2023), were used to calculate take by Level A 
harassment. The proportion of Steller sea lions detected between 60 m 
and the largest level A zone (130 m based on 2018 Technical Guidance, 
updated to 1,087 m based on the 2024 Technical Guidance) was multiplied 
by group size, number of daily sightings, and the number of 
construction days when impact pile driving would occur according to 
this equation:

Take by Level A harassment = group size x groups per day x days of 
impact pile driving activity x proportion of Steller sea lions observed 
occurring between 60 m and the largest level A zone during geotechnical 
drilling.

    Take estimates were rounded up to the nearest whole number in table 
10.
Gray Whale
    CBS requested take by Level B harassment of 31 gray whales, based 
on an estimated 1 gray whale every 2 days for 62 construction days. 
However, during weekly surveys conducted from September to May between 
1995 and 2000, gray whales were infrequently observed in groups of 3 
from Whale Park. As such, NMFS proposed 1 group of 3 gray whales every 
14 construction days (62/14 construction days = 4.4 2-week construction 
week periods), resulting in 14 takes by Level B harassment (1 group x 3 
gray whales x 4.4 construction periods = 13.2 takes by Level B 
harassment).
    The shutdown zone exceeds the calculated Level A harassment zone 
except during impact pile driving of 36-in steel piles (support and 
battered), estimated across 30 construction days. As such, it is 
possible that gray whales may occur in the Level A harassment zone and 
stay long enough to incur AUD INJ before exiting during those 30 days. 
For 36-in support piles, the ratio of the Level A harassment area 
(km\2\) that exceeds the shutdown zone to the maximum predicted Level B 
harassment area (km\2\) is 0.06. This activity is estimated to take 
place on 20 construction days. For 36-in batter piles, the ratio of the 
Level A harassment area (km\2\) that exceeds the shutdown zone to the 
Level B harassment area is 0.16. This activity is estimated to take 
place on 10 construction days. As such, 3 takes by Level A harassment 
are estimated [(0.06 x 4.4 construction periods x 1 group x 3 gray 
whales) + (0.16 x 4.4 construction periods x 1 group x 3 gray whales) = 
2.9 takes by Level A harassment].
    Any individuals exposed to the higher levels associated with the 
potential for AUD INJ closer to the source might also be behaviorally 
disturbed, however, for the purposes of quantifying take we do not 
count those exposures of one individual as a take by both Level A and

[[Page 92636]]

Level B harassment. Therefore, takes by Level B harassment calculated 
as described above were further modified to deduct the authorized 
amount of take by Level A harassment. Therefore, NMFS has authorized 3 
takes by Level A harassment and 11 takes by Level B harassment for gray 
whale, for a total of 14 takes. When allocating take across stocks, 
take estimates are rounded up to the nearest whole number.
Humpback Whale
    CBS requested take by Level B harassment of 248 humpback whales, 
based on an estimated 4 humpback whales occurring every 1 construction 
day for 62 construction days. NMFS concurred with this take estimate, 
acknowledging that 2 groups of 2 humpback whales occurring each 
construction day is reasonable based on previous monitoring data (2 
groups x 2 humpback whales x 62 construction days = 248 takes by Level 
B harassment of humpback whale).
    The shutdown zone exceeds the calculated Level A harassment zone 
except during impact pile driving of 36-in steel piles (support and 
battered), estimated across 30 construction days. As such, it is 
possible that humpback whales may occur in the Level A harassment zone 
and stay long enough to incur AUD INJ before exiting. For 36-in support 
piles, the ratio of the Level A harassment area (km\2\) that exceeds 
the shutdown zone to the maximum predicted Level B harassment area 
(km\2\) is 0.06. This activity is estimated to take place on 20 
construction days. For 36-in batter piles, the ratio of the Level A 
harassment area (km\2\) that exceeds the shutdown zone to the Level B 
harassment area is 0.16. This activity is estimated to take place on 10 
construction days. As such, 12 takes by Level A harassment are 
estimated [(0.06 x 20 construction days x 2 groups x 2 humpback whales) 
+ (0.16 x 10 construction days x 2 groups x 2 humpback whales) = 11.2 
takes by Level A harassment].
    Any individuals exposed to the higher levels associated with the 
potential for AUD INJ closer to the source might also be behaviorally 
disturbed, however, for the purposes of quantifying take we do not 
count those exposures of one individual as a take by both Level A and 
Level B harassment. Therefore, takes by Level B harassment calculated 
as described above were further modified to deduct the amount of take 
by Level A harassment. Therefore, NMFS has authorized 12 takes by Level 
A harassment and 236 takes by Level B harassment for humpback whale, 
for a total of 248 takes. When allocating take across stocks, take 
estimates are rounded up to the nearest whole number.
Killer Whale
    CBS requested take by Level B harassment of 31 killer whales, based 
on an estimated 1 killer whale occurring every 2 construction days for 
62 construction days. However, because killer whales were unpredictably 
observed from Whale Park in groups of 4-8 during weekly surveys 
conducted from September to May between 1995 and 2000, NMFS found it 
more appropriate to propose 1 group of 8 killer whales every 7 
construction days (62/7 construction days = 8.9 construction weeks), 
and has authorized the resulting 71 takes by Level B harassment (1 
group x 8 killer whales x 8.9 construction weeks = 71 takes by Level B 
harassment). No takes by Level A harassment were requested or are 
authorized.
Pacific White-Sided Dolphin
    CBS requested take by Level B harassment of 16 Pacific white-sided 
dolphin, based on an estimated 1 Pacific white-sided dolphin occurring 
every 4 construction days for 62 construction days. However, although a 
rare occurrence, Pacific white-sided dolphin were observed in groups 
averaging 4 individuals when sighted from Whale Park during weekly 
surveys conducted from September to May between 1995 and 2000. As such, 
NMFS finds it more appropriate to authorize 1 group of 4 Pacific white-
sided dolphin every 14 construction days (62 / 14 = 4.4 2-week 
construction periods), resulting in 18 authorized takes by Level B 
harassment (1 group x 4 Pacific white-sided dolphin x construction 4.4 
periods = 17.6 takes by Level B harassment). No takes by Level A 
harassment were requested or proposed for authorization (89 FR 56317, 
July 9, 2024).
    However, using the 2024 Technical Guidance, the re-calculated Level 
A harassment zone exceeds the planned shutdown zone during impact 
installation of 36-in steel piles (estimated to occur on 30 
construction days). NMFS therefore finds it appropriate to authorize 4 
takes by Level A harassment of Pacific white-sided dolphin, which is 
derived from the following: For 36-in support piles, the ratio of the 
Level A harassment area (km\2\) that exceeds the shutdown zone to the 
maximum predicted Level B harassment area (km\2\) is 0.003. This 
activity is estimated to take place on 20 construction days (20 
construction days / 14 days = 1.43 2-week construction periods). For 
36-in batter piles, the ratio of the Level A harassment area (km\2\) 
that exceeds the shutdown zone to the Level B harassment area is 0.01. 
This activity is estimated to take place on 10 construction days (10 
construction days / 14 days = 0.71 2-week periods). As such, 0.05 takes 
by Level A harassment are estimated [(0.0 x 1.43 construction days x 1 
group x 4 Pacific white-sided dolphin) + (0.01 x 0.71 construction days 
x 1 group x 4 pacific white-sided dolphin) = 0.05 takes by Level A 
harassment]. The take by Level A harassment estimate was then increased 
to the minimum estimated group size of 4 for Pacific white-sided 
dolphin.
    Any individuals exposed to the higher levels associated with the 
potential for AUD INJ closer to the source might also be behaviorally 
disturbed, however, for the purposes of quantifying take we do not 
count those exposures of one individual as a take by both Level A and 
Level B harassment. Therefore, takes by Level B harassment calculated 
as described above were further modified to deduct the amount of take 
by Level A harassment. Thus, NMFS has authorized 4 takes by Level A 
harassment and 14 takes by Level B harassment for Pacific white-sided 
dolphin, for a total of 18 takes. When allocating take across stocks, 
take estimates are rounded up to the nearest whole number.
Harbor Porpoise
    CBS requested take by Level B harassment of 16 harbor porpoise, 
based on an estimated 1 harbor porpoise occurring every 4 construction 
days for 62 construction days. However, harbor porpoise were rarely 
observed from Whale Park in groups of five during weekly surveys 
conducted from September to May between 1995 and 2000. As such, NMFS 
finds it more appropriate to authorize 1 group of 5 harbor porpoise 
every 14 construction days (62 / 14 construction days = 4.4 2-week 
construction week periods), resulting in 22 takes by Level B harassment 
(1 group x 5 harbor porpoises x 4.4 construction periods = 22 takes by 
Level B harassment).
    During impact pile driving of 36-in steel piles, estimated across 
30 construction days, the expected Level A harassment zone is larger 
than the planned shutdown zone (see Figure 1 of the Marine Mammal 
Mitigation and Monitoring Plan). As such, it is possible that harbor 
porpoise may enter the Level A harassment zone and stay long enough to 
incur AUD INJ before exiting. For 36-in support piles, the ratio of the 
Level A harassment area (km\2\) that exceeds the shutdown zone to the 
maximum predicted Level B harassment

[[Page 92637]]

area (km\2\) is 0.49 after applying the 2024 Technical Guidance 
(increased from 0.38). This activity is estimated to take place on 20 
construction days (20 construction days / 14 days = 1.43 2-week 
construction periods). For 36-in batter piles, the ratio of the portion 
of the Level A harassment area that exceeds the shutdown zone area 
(km\2\) to the maximum predicted Level B harassment area is 0.60 after 
applying the 2024 Technical Guidance (increased from 0.48). This 
activity is estimated to take place on 10 construction days (10 
construction days / 14 days = 0.71 2-week construction periods). As 
such, six instead of five takes by Level A harassment are authorized 
[(0.49 x 1 group x 5 harbor porpoise x 1.43 2-week construction 
periods) + (0.60 x 1 group x 5 harbor porpoises x 0.71 2-week 
construction periods) = 5.6 takes by Level A harassment].
    Any individuals exposed to the higher levels associated with the 
potential for AUD INJ closer to the source might also be behaviorally 
disturbed; however, for the purposes of quantifying take we do not 
count those exposures of one individual as a take by both Level A and 
Level B harassment. Therefore, takes by Level B harassment calculated 
as described above were further modified to deduct the amount of take 
by Level A harassment. Thus, NMFS has authorized 6 takes by Level A 
harassment and 16 takes by Level B harassment for harbor porpoise, for 
a total of 22 takes.
Steller Sea Lion
    CBS requested take by Level B harassment of 496 Steller sea lions, 
based on an estimated 8 Steller sea lions occurring every 1 
construction day for 62 construction days. NMFS concurs with this take 
estimate, acknowledging that four groups of two Steller sea lions 
occurring each construction day is reasonable based on previous 
monitoring data (2 groups x 4 Steller sea lion x 62 construction days = 
496 takes by Level B harassment of Steller sea lion).
    During impact pile driving of 36-in steel piles, estimated across 
30 construction days, the expected Level A harassment zone is larger 
than the shutdown zone. As such, it is possible that Steller sea lion 
may enter the Level A harassment zone and stay long enough to incur AUD 
INJ before exiting. For 36-in support piles, the ratio of the Level A 
harassment area that exceeds the planned shutdown zone (km\2\) to the 
maximum predicted Level B harassment area (km\2\) for is 0.07 after 
applying the 2024 Technical Guidance (increased from 0.001). This 
activity is estimated to take place on 20 construction days. For 36-in 
batter piles, the ratio of the Level A harassment area (km\2\) to the 
maximum predicted Level B harassment area is 0.1 after applying the 
2024 Technical Guidance (increased from 0.002). This activity is 
estimated to take place on 10 construction days. As such, one take by 
Level A harassment was estimated [(0.07 x 20 construction days x 2 
groups x 4 Steller sea lion x 20 construction days) + (0.1 x 10 
construction days x 2 groups x 4 Steller sea lion x 10 construction 
days) = 19.2 takes by Level A harassment].
    However, the 19.2 takes by Level A harassment estimated using the 
method described above likely does not reflect the true occurrence of 
Steller sea lion in the project area. Based on monitoring data 
collected during geotechnical survey conducted to inform CBS's IHA 
application, Steller sea lions are expected to disproportionally occur 
within close proximity to the project site. All (100 percent) Steller 
sea lions documented during that survey were observed between 60 m and 
1,087.9 m, which corresponds to the Level A zones during impact pile 
driving of 36-in piles after applying the 2024 Technical Guidance. 
These scenarios may occur on up to 30 construction days. Therefore 240 
additional takes by Level A harassment are anticipated (2 groups of 4 
Steller sea lion x 30 construction days x 1 = 240 takes by Level A 
harassment).
    Any individuals exposed to the higher levels associated with the 
potential for AUD INJ closer to the source might also be behaviorally 
disturbed, however, for the purposes of quantifying take we do not 
count those exposures of one individual as a take by both Level A and 
Level B harassment. Therefore takes by Level B harassment calculated as 
described above are further modified to deduct the authorized amount of 
take by Level A harassment. Thus, NMFS has authorized 240 takes by 
Level A harassment and 256 takes by Level B harassment for Steller sea 
lion, for a total of 496 takes.
California Sea Lion
    CBS requested take by Level B harassment of five California sea 
lions, based on an estimated one California sea lion occurring every 
month that construction is planned (October to March = 5 months) to 
account for the unlikely but small possibility that California sea lion 
could occur in the project area. However, NMFS finds it more 
appropriate to estimate take by Level B harassment according to 
duration of in-water work (62 construction days/30 days in 1 month = 
2.06 construction months). As such, NMFS authorized take by Level B 
harassment of three California sea lion (1 group x 1 California sea 
lion x 2.06 construction months = 2.06 takes by Level B harassment of 
California sea lion). After applying the 2024 Technical Guidance, 
calculated Level A harassment isopleths increased to 830 m and 1,087 m 
during impact pile driving activities, which is much further than the 
distances at which we estimate this species can reliably be observed by 
PSOs. As such NMFS has authorized a maximum total of 3 takes by either 
Level B or Level A harassment.
Northern Fur Seal
    CBS requested take by Level B harassment of five northern fur 
seals, based on an estimated one northern fur seal occurring every 
month that construction is planned (October-March = 5 months) to 
account for the unlikely but small possibility that northern fur seals 
could occur in the project area. However, NMFS finds it more 
appropriate to estimate take by Level B harassment according to the 
duration of in-water work (62 construction days/30 days in 1 month = 
2.06 months). As such, NMFS authorized take by Level B harassment of 
three northern fur seals (1 group x 1 northern fur seal x 2.06 
construction months = 2.06 takes by Level B harassment of northern fur 
seal). After applying the 2024 Technical Guidance, calculated Level A 
harassment isopleths increased to 830 m and 1,087 m during impact pile 
driving activities, which is much further than the distances at which 
we estimate this species can reliably be observed by PSOs. As such, 
NMFS has authorized a maximum total of 3 takes by either Level B or 
Level A harassment.
Harbor Seal
    CBS requested take by Level B harassment of 124 harbor seals, based 
on an estimated 2 harbor seals occurring every 2 construction days for 
62 construction days. However, because harbor seals are frequently 
documented in the project area, NMFS finds it more appropriate to 
authorize 186 takes by Level B harassment of harbor seal, based on the 
maximum groups size of 3 documented at the project site in 2017 (1 
group x 3 harbor seal x 62 construction days = 186 takes by Level B 
harassment).
    During impact pile driving of 36-in steel piles, estimated across 
30 construction days, the expected Level A harassment zone is larger 
than the planned shutdown zone. As such, it is possible that harbor 
seal may enter the Level A harassment zone and stay long enough to 
incur AUD INJ before exiting.

[[Page 92638]]

For 36-in support piles, the ratio of the Level A harassment area 
(km\2\) that exceeds the planned shutdown zone to the Level B 
harassment area (km\2\) is 0.27 after applying the 2024 Technical 
Guidance (increased from 0.16). This activity is estimated to take 
place on 20 construction days. For 36-in batter piles, the ratio of the 
Level A harassment area that exceeds the shutdown zone area (km\2\) to 
the maximum predicted Level B harassment area is 0.24 after applying 
the 2024 Technical Guidance (increased from 0.23). This activity is 
estimated to take place on 10 construction days. As such, 34 takes by 
Level A harassment are estimated [(0.27 x 20 construction days x 1 
group x 3 harbor seals) + (0.34 x 10 construction days x 1 group x 3 
harbor seals) = 52.8 takes by Level A harassment].
    Any individuals exposed to the higher levels associated with the 
potential for AUD INJ closer to the source might also be behaviorally 
disturbed, however, for the purposes of quantifying take we do not 
count those exposures of one individual as a take by both Level A and 
Level B harassment. Therefore, takes by Level B harassment calculated 
as described above are further modified to deduct the amount of take by 
Level A harassment. Thus, NMFS has authorized 53 takes by Level A 
harassment and 133 takes by Level B harassment for harbor seal, for a 
total of 186 takes.
    The total takes authorized for all species are summarized in table 
10 below, which reflects changes incorporated after applying the 2024 
Technical Guidance. Take by Level A harassment is authorized for a 
total of 3 individuals for gray whale, 12 individuals for humpback 
whale, 4 individuals for Pacific white-sided dolphin (increased from 
0), 6 individuals for harbor porpoise (increased from 5), 240 
individuals for Steller sea lion (increased from 88), 53 (increased 
from 34) individuals for harbor seal, 3 individuals of California sea 
lion (increased from 0), and 3 individuals of Northern fur seal 
(increased from 0).

     Table 10--Take by Stock and Harassment Type and as a Percentage of Stock Abundance Presented in Proposed FRN (89 FR 56317, July 9, 2024) and as
                                                 Authorized Based on the Updated 2024 Technical Guidance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Proposed authorized take \1\                Authorized take \1\         Authorized
                                                           ------------------------------------------------------------------------------    take as a
              Species                        Stock                                                                                         percentage of
                                                              Level B harassment     Level A harassment       Level B         Level A          stock
                                                                                                            harassment      harassment       abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale.........................  Eastern N. Pacific...  11...................  3....................              11               3              <1
Humpback Whale \2\.................  Mexico--North Pacific  5....................  1....................               5               1              <1
                                     Hawai[revaps]i.......  231..................  11...................             231              11             2.2
Killer Whale \3\...................  ENP Alaska Resident..  44...................  0....................              44               0             2.3
                                     ENP Northern Resident  7....................  0....................               7               0             2.3
                                     ENP Gulf of Alaska,    14...................  0....................              14               0             2.4
                                      Aleutian Islands,
                                      and Bering Sea.
                                     West Coast Transient.  8....................  0....................               8               0             2.3
Pacific white-sided dolphin........  North Pacific........  18...................  0....................              14               4              <1
Harbor Porpoise....................  Yakutat/Southeast      17...................  5....................              16               6           (\4\)
                                      Alaska Offshore
                                      Waters.
Steller sea lion \5\...............  Western DPS..........  5....................  1....................               4               3              <1
                                     Eastern DPS..........  402..................  88...................             252             237             1.3
                                                                                                         --------------------------------
California sea lion................  United States........  3....................  0....................                 3                            <1
                                                                                                         --------------------------------
Northern fur seal..................  Eastern Pacific......  3....................  0....................                 3                            <1
                                                                                                         --------------------------------
Harbor Seal........................  Sitka/Chatham Strait.  152..................  34...................             133              53             1.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ When allocating take across stocks, take estimates are rounded up to the nearest whole number.
\2\ 2 percent of take by Level A and Level B harassment of humpback whales are allocated to the Mexico DPS according to NMFS, 2021.
\3\ Take by level B harassment of killer whale is allocated across stocks according to the proportion of the stock compared to total number of animals
  in all four stocks that could occur in the project area: Alaska Residents, 60.7 percent; Northern Residents, 9.6 percent; Gulf of Alaska, Aleutian
  Islands, and Bering Sea: 18.6 percent ; West Coast Transient, 11.1 percent.
\4\ A reliable abundance estimate for this stock is currently unavailable.
\5\ 1.2 percent take by Level A and Level B harassment of Steller sea lions are allocated to the Western DPS according to Hastings et al. (2020).

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on

[[Page 92639]]

species or stocks and their habitat, as well as subsistence uses where 
applicable, NMFS considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, as 
well as subsistence uses. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope, range). It further 
considers the likelihood that the measure will be effective if 
implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, and impact on 
operations.

Mitigation for Marine Mammals and Their Habitat

    Shutdown Zones--For all pile driving activities, CBS plans to 
implement shutdowns within designated zones. The purpose of a shutdown 
zone is generally to define an area within which shutdown of the 
activity will occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
vary based on the activity type and marine mammal species or hearing 
group (table 11 and table 12). In most cases, the shutdown zones are 
based on the estimated Level A harassment isopleth distances for each 
hearing group. However, in cases where it would be challenging to 
detect marine mammals at the Level A harassment isopleth (e.g., for all 
species during impact pile driving except killer whale, after 
application of the 2024 Technical Guidance) and/or frequent shutdowns 
would create practicability concerns (e.g., Steller sea lions during 
impact pile driving), smaller shutdown zones are planned (table 12).
    Construction supervisors and crews, PSOs, and relevant CBS staff 
must avoid direct physical interaction with marine mammals during 
construction activity. If a marine mammal comes within 10 m of such 
activity, operations must cease and vessels must reduce speed to the 
minimum level required to maintain steerage and safe working 
conditions, as necessary to avoid direct physical interaction. If an 
activity 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 
indicated in table 11, or 15 minutes have passed without re-detection 
of the animal.
    Finally, construction activities must be halted upon observation of 
a species for which incidental take is not authorized or a species for 
which incidental take has been authorized but the authorized number of 
takes has been met entering or within any harassment zone. If a marine 
mammal species not covered under this IHA enters a harassment zone, all 
in-water activities will cease until the animal leaves the zone or has 
not been observed for at least 15 minutes, and NMFS would be notified 
about species and precautions taken. Pile driving will proceed if the 
unauthorized species is observed leaving the harassment zone or if 15 
minutes have passed since the last observation.

                                                 Table 11--Shutdown Zones Presented in the Proposed FRN
                                                               [89 FR 56317, July 9, 2024]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         Shutdown zones (m)
                                                                           -----------------------------------------------------------------------------
                                                                                                                                           OW
               Pile size/type                            Method                                                                -------------------------
                                                                                 LF           MF           HF           PW      Steller sea
                                                                                                                                    lion       Other OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Support Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile......................  Vibratory Installation.......           30           10           40           20           10           10
                                             Impact Installation..........        2,000           90          300          130           60          100
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Batter Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile......................  Vibratory Installation.......           40           10           60           30           10           10
                                             Impact Installation..........        2,000          120          300          130           60          130
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Fender Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile......................  Vibratory Installation.......           20           10           30           10           10           10
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Template Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile......................  Vibratory Installation and              20           10           30           20           10           10
                                              removal.
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                           Table 12--Final Shutdown zones based on the 2024 Technical Guidance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Shutdown zones (m)
                                                                         -------------------------------------------------------------------------------
                                                                                             HF \1\                                          OW
              Pile size/type                           Method                       ------------------------                      ----------------------
                                                                              LF       Killer                 VHF \2\       PW       Steller
                                                                                        whale     Other HF                          sea lion    Other OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Support Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile.....................  Vibratory Installation......     \3\ 40      \3\ 20      \3\ 20         40     \3\ 50      \3\ 20     \3\ 20
                                            Impact Installation.........      2,000     \3\ 320     \4\ 300        300        130          60    \4\ 130
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Batter Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pipe Pile.....................  Vibratory Installation......     \3\ 60      \3\ 20      \3\ 20         60     \3\ 70      \3\ 30     \3\ 30

[[Page 92640]]

 
                                            Impact Installation.........      2,000     \3\ 420     \4\ 300        300        130          60        130
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Haulout Pier Fender Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile.....................  Vibratory Installation......         20          10          10         30     \3\ 30          10         10
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Template Pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile.....................  Vibratory Installation and       \3\ 30          10          10         30         40          20         20
                                             removal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Species that were considered Mid-Frequency cetaceans under the NMFS 2018 Technical Guidance are now considered High Frequency cetaceans.
\2\ Species that were considered High-Frequency cetaceans under the NMFS 2018 Technical Guidance are now considered Very High Frequency cetaceans.
\3\ Shutdown zones have been increased to meet the calculated Level A harassment isopleths using the 2024 Technical Guidance.
\4\ Shutdown zones have been increased to the extent that this hearing group is expected to be reliably observable.

    Protected Species Observers--The number and placement of PSOs 
during all construction activities (described in the Monitoring and 
Reporting section) would ensure that the entire shutdown zone is 
visible during impact pile driving. In such cases, PSOs will monitor 
the Level A harassment zone and corresponding shutdown zone to the 
greatest extent practicable. CBS will employ at least three PSOs for 
all pile driving activities.
    Monitoring for Level A and Level B Harassment--PSOs will monitor 
the shutdown zones and beyond to the extent that PSOs can see. 
Monitoring beyond the shutdown zones enables observers to be aware of, 
and communicate the presence of, marine mammals in the project areas 
outside the shutdown zones and thus prepare for a potential cessation 
of activity should the animal enter the shutdown zone. If a marine 
mammal enters either harassment zone, PSOs will document the marine 
mammal's presence and behavior.
    Pre-and Post-Activity Monitoring--Prior to the start of daily in-
water construction activity, or whenever a break in pile driving of 30 
minutes or longer occurs, PSOs will observe the shutdown zones and as 
much as the harassment zones as possible for a period of 30 minutes. 
Pre-start clearance monitoring must be conducted during periods of 
visibility sufficient for the lead PSO to determine that the shutdown 
zones are clear of marine mammals. If the shutdown zone is obscured by 
fog or poor lighting conditions, in-water construction activity will 
not be initiated until the entire shutdown zone is visible. Pile 
driving may commence following 30 minutes of observation when the 
determination is made that the shutdown zones are clear of marine 
mammals. If a marine mammal is observed entering or within shutdown 
zones, pile-driving activity 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 
or 15 minutes have passed without re-detection of the animal. If a 
marine mammal for which take by Level B harassment is authorized is 
present in the Level B harassment zone, activities may begin.
    Soft-Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
will be required to provide an initial set of three strikes from the 
hammer at reduced energy, with each strike followed by a 30-second 
waiting period. This procedure will be conducted a total of three times 
before impact pile driving begins. Soft start will 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. 
Soft start is not required during vibratory pile driving activities.
    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. Note that the 
applicant opted to forgo the use of a bubble curtain as a mitigation 
measure as its use would decrease production rates due to the need to 
reposition the curtain around piles and vessel traffic, the need to 
maintain and operate the compressor, and delays associated with 
mechanical malfunctions.

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

[[Page 92641]]

cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    Visual Monitoring--Marine mammal monitoring during pile driving 
activities must be conducted by NMFS-approved PSOs 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 must 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 experience performing the duties of a PSO during construction 
activities pursuant to a NMFS-issued incidental take authorization;
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator will be designated. The lead 
observer will be required to have prior experience working as a marine 
mammal observer during construction activity pursuant to a NMFS-issued 
incidental take authorization; and
     PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    PSOs must also 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 identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including, but not limited to, the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was note 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.
    Visual monitoring will be conducted by a minimum of 3 trained PSOs 
positioned at suitable vantage points, such as the project site, 
Sawmill Creek Road and Medveje Hatchery (see figure 1 in CBS's Marine 
Mammal Mitigation and Monitoring Plan). During vibratory pile driving, 
at least one PSO will have an unobstructed view of all water within the 
shutdown zone. During impact pile driving, a second PSO will be placed 
at Sawmill Creek Road to ensure the largest shutdown zone extending 
into Eastern Channel is observable and a third PSO would be placed at 
Medvejie Hatchery to ensure as much of the shutdown zone in Silver Bay 
is observable as possible. All PSOs will be stationed on elevated 
platforms to aid in monitoring marine mammals.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after all in water construction activities. In addition, PSOs 
will record all incidents of marine mammal occurrence, regardless of 
distance from activity, and will 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

    CBS will submit a draft marine mammal monitoring report to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to a requested date of issuance of any future IHAs for the 
project, or other projects at the same location, whichever comes first. 
The marine mammal monitoring report will include an overall description 
of work completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report will include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including: (1) the number and type of piles that 
were driven and the method (e.g., impact or vibratory); and, (2) total 
duration of driving time for each pile (vibratory driving) and 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: (1) name of PSO who sighted the animal(s) and PSO location 
and activity at time of sighting; (2) time of sighting; (3) 
identification of the animal(s) (e.g., genus/species, lowest possible 
taxonomic level, or unidentified), PSO confidence in identification, 
and the composition of the group if there is a mix of species; (4) 
distance and location of each observed marine mammal relative to the 
pile being driven for each sighting; (5) estimated number of animals 
(min/max/best estimate); (6) estimated number of animals by cohort 
(adults, juveniles, neonates, group composition, etc.); (7) animal's 
closest point of approach and estimated time spent within the 
harassment zone; and, (8) description of any marine mammal behavioral 
observations (e.g., observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g., no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
     Number of marine mammals detected within the harassment 
zones, by species; and
     Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specific 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    A final report must be prepared and submitted within 30 calendar 
days following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered final. All PSO data 
will be submitted electronically in a format that can be queried such 
as a spreadsheet or database and will be submitted with the draft 
marine mammal report.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Holder must report the 
incident to the OPR, NMFS ([email protected] and 
[email protected]) and Alaska Regional Stranding network (877-925-
7773) as soon as feasible. If the death or injury was clearly caused by 
the

[[Page 92642]]

specified activity, the Holder must immediately cease the activities 
until NMFS OPR 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 this IHA. The 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, 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).
    The incorporation of the 2024 Updated Technical Guidance does not 
alter the original scope of the activity analyzed or our effects 
analysis in a manner that materially affects the basis for original 
findings under the IHA. Shutdown zones have been increased to meet or 
exceed the Level A harassment zone calculated using the 2024 Technical 
Guidance where practicable. In cases where the shutdown zones cannot be 
increased due to observability or practicability concerns, a slightly 
larger proportion of overall proposed take has been authorized as take 
by Level A harassment. However, the total take authorized remains the 
same as the take proposed for authorization during the public comment 
period for all species. Accordingly, we have determined that even with 
the incorporation of the 2024 Technical Guidance, this project will 
have a negligible impact on the affected species stocks and the 
negligible impact analysis presented in the proposed FRN remains 
applicable.
    To avoid repetition, the discussion of our analysis applies to all 
the species listed in table 1, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar. There is little information about the nature or severity of 
the impacts, or the size, status, or structure of any of these species 
or stocks that would lead to a different analysis for this activity.
    Pile driving and removal activities associated with the project, as 
outlined previously, have the potential to disturb or displace marine 
mammals. Specifically, the specified activities may result in take, in 
the form of Level B harassment and, for some species, Level A 
harassment from underwater sounds generated by pile driving and 
removal. Potential takes could occur if individuals are present in the 
ensonified zone when these activities are underway.
    No serious injury or mortality is expected, even in the absence of 
required mitigation measures, given the nature of the activities.
    Following the incorporation of the 2024 Updated Technical Guidance 
take by Level A harassment is authorized for all species except killer 
whale. 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.
    Further, the amount of take by Level A harassment authorized is 
very low for all marine mammal stocks and species, except Steller sea 
lion. NMFS expects no more than 3 takes by Level A harassment for gray 
whale, 12 takes by Level A harassment for humpback whale; 4 takes by 
Level A harassment for Pacific white-sided dolphin, 6 takes by Level A 
harassment for harbor porpoise; 53 takes by Level A harassment for 
harbor seal; 3 takes by Level A or Level B harassment for California 
sea lion; and, 3 takes by Level A or Level B harassment for Northern 
fur seal. Although 240 takes by Level A harassment for Steller sea lion 
are authorized, if hearing impairment occurs, it is most likely that 
the affected animal would lose only a few dB in its hearing 
sensitivity. Due to the small degree anticipated, any AUD INJ potential 
incurred would not be expected to affect the reproductive success or 
survival of any individuals, much less result in adverse impacts on the 
species or stock.
    Additionally, some subset of the individuals that are behaviorally 
harassed could also simultaneously incur some small degree of TTS for a 
short duration of time. However, since the hearing sensitivity of 
individuals that incur TTS is expected to recover completely within 
minutes to hours, it is unlikely that the brief hearing impairment 
would affect the individual's long-term ability to forage and 
communicate with conspecifics, and would therefore not likely impact 
reproduction or survival of any individual marine mammal, let alone 
adversely affect rates of recruitment or survival of the species or 
stock.
    Effects on individuals that are taken by Level B harassment in the 
form of behavioral disruption, on the basis of reports in the 
literature as well as monitoring from other similar activities, would 
likely be limited to reactions such as avoidance, increased swimming 
speeds, increased surfacing time, or decreased foraging (if such 
activity were occurring) (e.g., Thorson and Reyff, 2006). Most likely, 
individuals would simply move away from the sound source and 
temporarily avoid the area where pile driving is occurring. If sound 
produced by project activities is sufficiently disturbing, animals are 
likely to simply avoid the area while the activities are occurring. We 
expect that

[[Page 92643]]

any avoidance of the project areas by marine mammals would be temporary 
in nature and that any marine mammals that avoid the project areas 
during construction would not be permanently displaced. Short-term 
avoidance of the project areas and energetic impacts of interrupted 
foraging or other important behaviors is unlikely to affect the 
reproduction or survival of individual marine mammals, and the effects 
of behavioral disturbance on individuals is not likely to accrue in a 
manner that would affect the rates of recruitment or survival of any 
affected stock.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may cause a low level of turbidity in 
the water column and some fish may leave the area of disturbance, thus 
temporarily impacting marine mammals' foraging opportunities in a 
limited portion of the foraging range; but, because of the short 
duration of the activities and the relatively small area of the habitat 
that may be affected (with no known particular importance to marine 
mammals), the impacts to marine mammal habitat are not expected to 
cause significant or long-term negative consequences.
    While Steller sea lions are common in the project area, there are 
no essential primary constituent elements, such as haulouts or 
rookeries, present. The nearest haulout is well over 25 km away. 
Therefore, the project is not expected to have significant adverse 
effects on the critical habitat of Western DPS Steller sea lions. No 
areas of specific biological importance (e.g., ESA critical habitat, 
BIAs, or other areas) for any other species are known to co-occur with 
the project area.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on each stock's ability 
to recover. In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activities 
would have only minor, short-term effects on individuals. The specified 
activities are not expected to impact rates of recruitment or survival 
and would therefore not result in population-level impacts.
    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 of a low degree, and except 
for Eastern DPS Steller sea lion and harbor seal, of very small 
amounts;
     For all species, Silver Bay and East Channel are a very 
small and peripheral part of their range;
     Anticipated takes by Level B harassment are relatively low 
for all stocks. Level B harassment would be primarily in the form of 
behavioral disturbance, resulting in avoidance of the project areas 
around where impact or vibratory pile driving 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 
activities;
     Effects on species that serve as prey for marine mammals 
from the activities are expected to be short-term and, therefore, any 
associated impacts on marine mammal feeding are not expected to result 
in significant or long-term consequences for individuals, or to accrue 
to adverse impacts on their populations;
     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 lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and
     CBS will implement mitigation measures including visual 
monitoring, soft-start, and shutdown zones to minimize the numbers of 
marine mammals exposed to injurious levels of sound, and to ensure that 
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 planned 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 authorized is below one third of the 
estimated stock abundance for all species. This is likely a 
conservative estimate because we assume all takes are of different 
individual animals, which likely would not be the case. Some 
individuals may return multiple times in a day, but PSOs will count 
them as separate takes if they cannot be individually identified.
    The most recent abundance estimate for the Mexico-North Pacific 
stock of humpback whale is likely unreliable as it is more than eight 
years old. The most relevant estimate of this stock's abundance in 
Southeast Alaska is 918 humpback whales (Wade, 2021), so the 4 
authorized takes by Level B harassment and 1 authorized take by Level A 
harassment is small relative to the estimated abundance (<1 percent), 
even if each authorized take occurred to a new individual.
    There is no abundance information available for the Yakutat/
Southeast Alaska stock of harbor porpoise. However, the take numbers 
are sufficiently small (16 takes by Level B harassment and 6 takes by 
Level A harassment, updated from 17 takes by Level B harassment and 5 
takes by Level A harassment after applying the 2024 Technical Guidance) 
that we can safely assume that they are small relative to any 
reasonable assumption of likely population abundance for these stocks. 
For reference, current abundance estimates for harbor porpoise stocks 
in Southeast Alaska include 1,619 (Northern Southeast Alaska Inland 
Waters) and 890 (Southern Southeast Alaska Inland Waters).
    Based on the analysis contained herein of the planned 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.

[[Page 92644]]

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 
Sec.  216.103 as an impact resulting from the specified activity that: 
(1) 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) cannot 
be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    For marine mammals, Alaska Natives have traditionally harvested 
harbor seals and Steller sea lions in Sitka, Alaska. During the most 
recent ADF&G subsistence harvest report (2013), about 11 percent of 
Sitka households used subsistence-caught marine mammals, however, this 
is the most recent data available and there has not been a survey since 
2013 (ADF&G, 2023).
    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 because:
     There is no recent recorded subsistence harvest of marine 
mammals in the area;
     Construction activities are temporary and localized to the 
Gary Paxton Industrial Park, and industrial area;
     Construction will not take place during the herring 
spawning season when subsistence species are more active;
     Mitigation measures will be implemented to minimize 
disturbance of marine mammals in the action area; and
     The project will not result in significant changes to 
availability of subsistence resources.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the planned mitigation and 
monitoring measures, NMFS has determined that there will not be an 
unmitigable adverse impact on subsistence uses from CBS's planned 
activities.

Endangered Species Act

    Section 7(a)(2) of the ESA of 1973 (ESA; 16 U.S.C. 1531 et seq.) 
requires that each Federal agency insure that any action it authorizes, 
funds, or carries out is not likely to jeopardize the continued 
existence of any endangered or threatened species or result in the 
destruction or adverse modification of designated critical habitat. To 
ensure ESA compliance for the issuance of IHAs, NMFS consults 
internally whenever we propose to authorize take for endangered or 
threatened species, in this case with the Alaska Regional Office 
(AKRO).
    NMFS is authorizing take of western DPS of Steller sea lions and 
the Mexico DPS of humpback whales, which are listed under the ESA. The 
NMFS AKRO issued a Biological Opinion under Section 7 of the ESA on the 
issuance of an IHA to CBS under section 1010(a)(5)(D) of the MMPA by 
NMFS OPR. The biological opinion concluded that the action is not 
likely to jeopardize the continued existence of the listed species.

National Environmental Policy Act (NEPA)

    To comply with the NEPA of 1969 (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 the IHA qualifies to be categorically excluded from further 
NEPA review.

Authorization

    NMFS has issued an IHA to CBS for the potential harassment of small 
numbers of nine marine mammal species incidental to the Gary Paxton 
Industrial Park Vessel Haulout project in Sitka, Alaska, that includes 
the previously explained mitigation, monitoring and reporting 
requirements.

    Dated: November 18, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2024-27342 Filed 11-21-24; 8:45 am]
BILLING CODE 3510-22-P`