Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Whittier Head of the Bay Cruise Ship Dock Project in Whittier, Alaska, 19927-19940 [2023-06895]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 64 (Tuesday, April 4, 2023)]
[Notices]
[Pages 19927-19940]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-06895]


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

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC802]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Whittier Head of the Bay Cruise 
Ship Dock Project in Whittier, Alaska

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

ACTION: Notice; issuance of an incidental harassment authorization.

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

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 
Turnagain Marine Construction (TMC) to incidentally harass marine 
mammals during construction associated with the Whittier Head of the 
Bay cruise ship dock project in Whittier, Alaska.

DATES: This authorization is effective from April 1, 2023, through 
March 31, 2024.

FOR FURTHER INFORMATION CONTACT: Jenna Harlacher, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-turnagain-marine-constructions-cruise-dock-construction. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed 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 September 16, 2022, NMFS received a request from TMC for an IHA 
to take marine mammals incidental to the construction of the cruise 
ship dock in Whittier, Alaska. Following NMFS' review of the 
application, TMC provided further information on October 26, 2022, a 
revised application on January 9, 2023, and the application was deemed 
adequate and complete on January 10, 2023. Subsequently, TMC submitted 
an additional update to its application on February 3, 2023. The 
proposed IHA published for public comment on February 13, 2023 (88 FR 
9227). TMC's request is for take of five species of marine mammals by 
Level B harassment and, for a subset of two species, Level A 
harassment. Neither TMC, nor NMFS expect serious injury or mortality to 
result from this activity and, therefore, an IHA is appropriate.

Description of Activity

    TMC plans to construct the Whittier Head of the Bay cruise ship 
dock project in the Passage Canal in Whittier, Alaska. The planned 
project will cover a 12-month window during which approximately 129 
days of pile-installation and -removal activity will occur. This 
project involves installation and removal of seventy-two 36-inch (in) 
(0.91-meter (m)) temporary steel pile guides and installation of 
thirty-six 36-in (0.91-m), sixteen 42-in (1.1-m), and twenty 48-in 
(1.2-m) permanent steel piles. Three different installation methods 
will be used including vibratory installation of piles into dense 
material, impact pile driving to drive piling to tip elevation, and the 
Down-the-Hole (DTH) hammer to drill pile into the bedrock. TMC will 
deploy a bubble curtain to the 60-foot (ft) (18.3-m) isobath. This will 
be used during all activities that fall below the 60-ft (18.3-m) 
isobath. Sounds resulting from pile installation, removal, and drilling 
may result in the incidental take of marine mammals by Level A and 
Level B harassment in the form of auditory injury or behavioral 
harassment.
    A further detailed description of the planned construction project 
is provided in the Federal Register notice for the proposed IHA (88 FR 
9777, February 13, 2023). Since that time, no changes have been made to 
the planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for the 
description of the specified activity. Mitigation, monitoring, and 
reporting measures are described in detail later in this document 
(please see Mitigation and Monitoring and Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to TMC was published in 
the Federal Register on February 13, 2023 (88 FR 9777). That notice 
described, in detail, TMC's activity, the marine mammal species that 
may be affected by the activity, and the anticipated effects on marine 
mammals. During the 30-day public comment period, no public comments 
were received.

Changes From the Proposed IHA to Final IHA

    Changes were made between publication of the notice of proposed IHA 
and this notice of final IHA. Changes have been made to correct 
typographical errors to Tables 4, 5, and 8 in the proposed Federal 
Register notice; however, the proposed IHA at the time of publishing 
was correct. Additionally, text regarding a 35-m

[[Page 19928]]

(114.83-ft) minimum shutdown zone was removed and replaced with the 
applicant's specified minimum shutdown zones that reflects the zones 
included in Table 8. Lastly, reasoning for the killer whale take 
calculation and shutdown zones for impact pile driving was included to 
correctly reflect what was included in the proposed notice.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, incorporated here by reference, instead of 
reprinting the information. Additional information regarding population 
trends and threats may be found in NMFS' Stock Assessment Reports 
(SARs; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these 
species (e.g., physical and behavioral descriptions) may be found on 
NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 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 stocks managed under the MMPA in this region 
are assessed in NMFS' U.S. 2021 SARs (e.g., Muto et al., 2021) and the 
draft 2022 SARs (e.g., Young et al., 2022). All values presented in 
Table 1 are the most recent available at the time of publication and 
are available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments).

                                              Table 1--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balae nopteridae (rorquals):
Humpback whale......................  Megaptera novaeanglinae  Central North Pacific    -,D,Y               10,103 (0.3, 7,890,            83         26
                                                                Stock.                                       2006).
                                      .......................  Western North Pacific    E,D,Y               1,107 (0.3, 865, 2006)          3        2.8
                                                               California/Oregon/       T,D,Y               4,973 (0.05, 4,776,          28.7       48.3
                                                                Washington.                                  2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer whale........................  Orca orcinus...........  Alaska Resident........  -,-,N               1,920 (N/A, 1,920,             19        1.3
                                                                                                             2019).
                                                               Gulf of Alaska/Aleutian  -,-,N               587 (N/A, 587, 2012)..        5.9        0.8
                                                                Islands/Bering Sea
                                                                Transient.
                                                               AT1 Transient..........  -,D,Y               7 (N/A, 7, 2019)......       0.01          1
Family Phocoenidae (porpoises):
Dall's porpoise \4\.................  Phocoenoides dalli.....  Alaska Stock...........  -,-,N               15,432 (0.097, 13,            131         37
                                                                                                             110, 2021).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
Steller sea lion....................  Eumetopias jubatus.....  Western Stock..........  E,D,Y               52,932 (N/A, 52,932,          318        254
                                                                                                             2019).
Family Phocidae (earless seals):
Harbor seal.........................  Phoca vituline           Clarence Strait Stock..  -,-,N               27,659 (N/A, 24,854,          746         40
                                       richardii.                                                            2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
\4\ Previous abundance estimates covering the entire stock's range are no longer considered reliable and the current estimates presented in the SARs and
  reported here only cover a portion of the stock's range. Therefore, the calculated Nmin and PBR is based on the 2015 survey of only a small portion of
  the stock's range. PBR is considered to be biased low since it is based on the whole stock whereas the estimate of mortality and serious injury is for
  the entire stock's range.


[[Page 19929]]

    On January 24, 2023, NMFS published the draft 2022 SARs (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region). The Alaska and Pacific Ocean SARs 
include a proposed update to the humpback whale stock structure. The 
new structure, if finalized, would modify the MMPA-designated stocks to 
align more closely with the ESA-designated Distinct Population Segments 
(DPS). Please refer to the draft 2022 Alaska and Pacific Ocean SARs for 
additional information.
    NMFS Office of Protected Resources, Permits and Conservation 
Division has generally considered peer-reviewed data in draft SARs 
(relative to data provided in the most recent final SARs), when 
available, as the best available science, and has done so here for all 
species and stocks, with the exception of a new proposal to revise 
humpback whale stock structure. Given that the proposed changes to the 
humpback whale stock structure involve application of NMFS' Guidance 
for Assessing Marine Mammals Stocks and could be revised following 
consideration of public comments, it is more appropriate to conduct our 
analysis in this authorization based on the status quo stock structure 
identified in the most recent final SARs (2021; Muto et al., 2022).
    As indicated above, all five species (with eight managed stocks) in 
Table 1 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur, and we have authorized 
it. All species that could potentially occur in the planned project 
areas are included in Table 1 of the IHA application. While some 
species have been reported in or near the area, it is very rare, and 
the temporal and/or spatial occurrence of these species is more likely 
outside of the Passage Canal and outside of the harassment zones. 
Therefore, given this information take is not expected to occur and 
they are not discussed further beyond the explanation provided here.
    A detailed description of the species likely to be affected by 
TMC's construction 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 (88 FR 9777, February 13, 2023); 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 the 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.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 2.

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

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

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the TMC's pile driving 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the project area. The notice of the 
proposed IHA (88 FR 9777, February 13, 2023) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from the TMC's pile driving activities on 
marine mammals and their habitat. That information and analysis is 
incorporated by reference into this final IHA determination and is not 
repeated here; please refer to the notice of the proposed IHA (88 FR 
9777, February 13, 2023).

[[Page 19930]]

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers,'' and the negligible impact determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes will primarily be by Level B harassment, as use of 
the acoustic sources (i.e., vibratory or impact pile driving and DTH) 
has the potential to result in disruption of behavioral patterns for 
individual marine mammals. There is also some potential for auditory 
injury (Level A harassment) to result for Dall's porpoise and harbor 
seals, due to the cryptic nature of these species in the context of 
large predicted auditory injury zones. Auditory injury is unlikely to 
occur for low- and mid-frequency species and otariids, based on the 
likelihood of the species in the action area, the ability to monitor 
the entire smaller shutdown zone, and because of the expected ease of 
detection for the former groups. 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 
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 Permanent Threshold Shift (PTS) of some 
degree (equated to Level A harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources. Generally speaking, Level B harassment take 
estimates based on these behavioral harassment thresholds are expected 
to include any likely takes by Temporary Threshold Shift (TTS) as, in 
most cases, the likelihood of TTS occurs at distances from the source 
less than those at which behavioral harassment is likely. TTS of a 
sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    TMC's activity includes the use of continuous (vibratory hammer and 
DTH) and impulsive (DTH and impact pile-driving) sources, and therefore 
the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are applicable.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). TMC's 
activity includes the use of impulsive (impact pile-driving and DTH) 
and non-impulsive (vibratory hammer and DTH) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds \*\ (received level)
----------------------------------------------------------------------------------------------------------------
             Hearing group                        Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.

[[Page 19931]]

 
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the planned project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving and removal, and DTH).
    In order to calculate distances to the Level A harassment and Level 
B harassment thresholds for the methods and piles being used in this 
project, NMFS used acoustic monitoring data from other locations to 
develop source levels for the various pile types, sizes, and methods 
(Table 4). Additionally, a bubble curtain will be deployed at a depth 
of 60-ft (18.3-m) and will be used during all activities that fall 
within the 60-ft (18.3-m) isobath. Therefore, a 5 dB reduction is 
applied to the estimated sound source levels for driving these piles 
only (Caltrans, 2020).

                        Table 4--Observed Source Levels for Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
        Pile size, method                   SPL (dB)                  SEL (dB)                  Reference
----------------------------------------------------------------------------------------------------------------
                                 Bubble Curtain in use (depths of 60 ft or less)
----------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory        161 RMS **...............  ........................  U.S. Navy 2015.
 Installation (temporary).
36-in steel pile, Vibratory        161 RMS **...............  ........................  U.S. Navy 2015.
 Removal (temporary).
36-in steel pile, DTH              169 RMS **...............  159 SEL **..............  Denes et al., 2019; Guan
 Installation (temporary) *.                                                             and Miner, 2020; Reyff
                                                                                         and Heyvaert, 2019;
                                                                                         Reyff, 2020; Heyvaert
                                                                                         and Reyff, 2021.
36-in steel pile, Vibratory        161 RMS **...............  ........................  U.S. Navy 2015.
 Installation (permanent).
36-in steel pile, Impact           187 RMS **...............  179 SEL **..............  U.S. Navy 2015.
 Installation (permanent).
36-in steel pile, DTH              169 RMS **...............  159 SEL **..............  Denes et al., 2019; Guan
 Installation (permanent) *.                                                             and Miner, 2020; Reyff
                                                                                         and Heyvaert, 2019;
                                                                                         Reyff, 2020; Heyvaert
                                                                                         and Reyff, 2021.
----------------------------------------------------------------------------------------------------------------
                                  No Bubble Curtain (depths greater than 60 ft)
----------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory        166 RMS..................  ........................  U.S. Navy 2015.
 Installation (temporary).
36-in steel pile, Vibratory        166 RMS..................  ........................  U.S. Navy 2015.
 Removal (temporary).
42-in steel pile, Vibratory        168.2 RMS................  ........................  Austin et al. 2016.
 Installation.
48-in steel pile, Vibratory        168.2 RMS................  ........................  Austin et al. 2016.
 Installation.
42-in steel pile, Impact           198.6 RMS................  186.7 SEL...............  Austin et al. 2016.
 Installation.
48-in steel pile, Impact           198.6 RMS................  186.7 SEL...............  Austin et al. 2016.
 Installation.
36-in steel pile, DTH              174 RMS..................  164 SEL.................  Denes et al., 2019; Guan
 Installation (temporary).                                                               and Miner, 2020; Reyff
                                                                                         and Heyvaert, 2019;
                                                                                         Reyff, 2020; Heyvaert
                                                                                         and Reyff, 2021.
42-in steel pile, DTH              174 RMS..................  164 SEL.................  Denes et al., 2019; Guan
 Installation *.                                                                         and Miner, 2020; Reyff
                                                                                         and Heyvaert, 2019;
                                                                                         Reyff, 2020; Heyvaert
                                                                                         and Reyff, 2021.
48-in steel pile, DTH              174 RMS..................  171 SEL.................  Denes et al., 2019; Guan
 Installation *.                                                                         and Miner, 2020; Reyff
                                                                                         and Heyvaert, 2019;
                                                                                         Reyff, 2020; Heyvaert
                                                                                         and Reyff, 2021.
----------------------------------------------------------------------------------------------------------------
Note: SELss = single strike sound exposure level; RMS = root mean square.
* Source levels here differ from those used in TMC's application as NMFS has updated their acoustic guidance on
  DTH, resulting in larger Level B harassment SPLs. (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance#other-nmfs-acoustic-thresholds-and-tools).
** Attenuated source levels with 5dB reduction due to use of a bubble curtain during these activities (Caltrans,
  2020; Austin et al., 2016).

    NMFS recommends treating DTH systems as both impulsive and 
continuous, non-impulsive sound source types simultaneously. Thus, 
impulsive thresholds are used to evaluate Level A harassment, and 
continuous thresholds are used to evaluate Level B harassment. With 
regards to DTH mono-hammers, NMFS recommends proxy levels for Level A 
harassment based on available data regarding DTH systems of similar 
sized piles and holes (Denes et al., 2019; Guan and Miner, 2020; Reyff 
and Heyvaert, 2019; Reyff, 2020; Heyvaert and Reyff, 2021).

Level B Harassment Zones

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * log10 (R1/R2),

Where:

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

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that lies between spherical and cylindrical 
spreading loss conditions, which is the most appropriate assumption for 
TMC's planned activities. The Level B harassment zones and areas of 
zones of

[[Page 19932]]

influence (ZOIs) for the planned activities are shown in Table 5.

Level A Harassment Zones

    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources, such as pile installation or removal, the optional 
User Spreadsheet tool predicts the distance at which, if a marine 
mammal remained at that distance for the duration of the activity, it 
would be expected to incur PTS. The isopleths generated by the User 
Spreadsheet used the same TL coefficient as the Level B harassment zone 
calculations (i.e., the practical spreading value of 15). Inputs used 
in the User Spreadsheet (e.g., number of piles per day, duration and/or 
strikes per pile) are presented in Table 1 of the notice of the 
proposed IHA (88 FR 9777, February 13, 2023). The maximum RMS SPL, SEL, 
and resulting isopleths are reported in Table 4 and 5.

                                      Table 5--Level A and Level B Harassment Isopleths for Pile Driving Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Level A harassment zone (m)                               Level B
                        Activity                         --------------------------------------------------------------------------------   harassment
                                                            LF cetacean     MF cetacean     HF cetacean       Phocids        Otariids        zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Bubble Curtain in use (depths of 60 ft or less)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory Installation (temporary)....             5.2             0.5             7.7             3.2             0.2           5,412
36-in steel pile, Vibratory Removal (temporary).........             5.2             0.5             7.7             3.2             0.2           5,412
36-in steel pile, DTH Installation (temporary)..........           681.1            24.5           820.9           368.8            26.9        * 18,479
36-in steel pile, Vibratory Installation (permanent)....             6.8             0.6            10.1             4.2             0.3           5,412
36-in steel pile, Impact Installation (permanent).......         2,015.1            71.7         2,400.3         1,078.4            78.5             631
36-in steel pile, DTH Installation (permanent) *........           799.7            28.4           952.6             428            31.2        * 18,479
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      No Bubble Curtain (depths greater than 60 ft)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory Installation (temporary)....            11.2               1            16.6             6.8             .05          11,659
36-in steel pile, Vibratory Removal (temporary).........            11.2               1            16.6             6.8             .05          11,659
42-in steel pile, Vibratory Installation................            20.6             1.8            30.5            12.5             0.9          16,343
48-in steel pile, Vibratory Installation................              13             1.2            19.2             7.9             0.6          16,343
42-in steel pile, Impact Installation...................         6,570.9           233.7           7,827         3,516.4             256           3,744
48-in steel pile, Impact Installation...................         5,014.6           178.4         5,973.1         2,683.6           195.4           3,744
36-in steel pile, DTH Installation (temporary)..........         1,484.7            52.8         1,768.5           794.6            57.9        * 39,811
42-in steel pile, DTH Installation *....................         1,722.9            61.3         2,052.2             922            67.1        * 39,811
48-in steel pile, DTH Installation *....................         5,045.7           179.5         6,010.2         2,700.2           196.6        * 39,811
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Differs from TMC's application due to difference in source level use. See Table 4.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including presence, local knowledge, group dynamics, or 
other relevant information, that will inform the take calculations. We 
also describe how the information provided above is brought together to 
produce a quantitative take estimate.
    Available information regarding marine mammal occurrence and 
abundance in the vicinity of the Passage Canal includes local 
knowledge, previous marine construction projects in the Whittier area, 
and available scientific literature. A summary of authorized take is in 
Table 7. To accurately describe species occurrence near the action 
area, marine mammals were described as either common or infrequent.
    To obtain more accurate estimates of potential take by Level B 
harassment, TMC estimated an hourly occurrence probability of each 
marine mammal species in the action area rather than a weekly or daily 
estimation, since pile driving activities will not occur over an entire 
day, but rather over a certain number of hours. Occurrence probability 
estimates are based on conservative density approximations for each 
species and factor in historic data of occurrence, seasonality, and 
group size in the Passage Canal and/or nearby Prince William Sound.
    Assumptions for these hourly estimations were that common species 
(Steller sea lion, harbor seal) would have two group sightings per day 
in the Passage Canal, and infrequent species would have three group 
sightings per week in the Passage Canal, or slightly fewer than one 
group sighting every two days (Table 6). In these estimations, a 
sighting does not equal one animal; a sighting equals one group of each 
particular species or stock. To standardize observation estimates 
across species, these numbers were distilled

[[Page 19933]]

down to obtain the hourly occurrence probability for each species. 
Additionally, one day was equated to 12 hours rather than 24 hours to 
obtain a rough estimate of observations during daylight hours when pile 
driving and project activities will occur, and to obtain more 
conservative estimates of species occurrence. TMC states that this 
hourly estimate provides a more accurate representation of actual 
possible takes in Passage Bay.

                        Table 6--Estimated Occurrence of Group Sighting of Marine Mammals
----------------------------------------------------------------------------------------------------------------
                                                                        Group sighting occurrence estimate
              Species occurrence in the action area              -----------------------------------------------
                                                                      Weekly           Daily          Hourly
----------------------------------------------------------------------------------------------------------------
Common (Steller sea lion, harbor seal)..........................              14               2            0.17
Infrequent (humpback whale, Dall's porpoise, killer whale)......               3             0.5            0.04
----------------------------------------------------------------------------------------------------------------

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and authorized.
    Take was estimated using the hourly occurrence probability for each 
species, which was multiplied by the estimated group size and by the 
number of hours of each type of pile driving activity for total take 
estimate.
    For species infrequently seen in Passage Canal (humpback whale, 
Dall's porpoise, and killer whale) and rarely seen close to the project 
location, only hours of pile driving for DTH and vibratory driving were 
used to calculate these species take estimates. Impact pile driving was 
excluded from these analyses because the Level A harassment isopleth 
was larger than the Level B harassment isopleth for low- and high-
frequency cetaceans, and therefore construction will be shut down 
before they approach the Level B harassment zone. However, for killer 
whales, impact pile driving was excluded because killer whales are an 
infrequent visitor to Passage Canal and often highly visible. For 
impact pile driving, TMC will conservatively apply thresholds for high 
frequency cetaceans to killer whales. This precautionary measure will 
reduce potential impacts to the highly vulnerable AT-1 killer whale 
stock that is found in this region should they enter the Passage Canal 
during the in-water work period.
    Take by Level A harassment is also requested for Dall's porpoise 
and harbor seals given their frequency in the action area, the large 
Level A harassment zones for HF cetaceans and phocids, the possibility 
they may not be seen in the water before pile driving could be shut 
down, and the fact that Level A harassment isopleths for certain pile 
driving activities extend to Whittier Seafood's outfall, a known marine 
mammal foraging area.
    The take calculations for Level A harassment are based on the 
occurrence estimate for the species in the largest Level B harassment 
zone (16,343 meters) reduced by a factor for each smaller Level A 
harassment isopleth. While NMFS updated the DTH source levels, 
resulting in DTH having the largest Level B harassment isopleth, the 
shoreline is limited in Passage Canal and the largest practical Level B 
harassment isopleth is the one used by TMC for the original calculation 
of take by Level A harassment. Therefore, the updated DTH values do not 
impact the take calculation. The Level A harassment isopleth for each 
species and specific activity was divided by the largest Level B 
harassment isopleth (16,343 m), giving a species multiplier per hour 
for occurrence in the smaller Level A harassment isopleth. This was 
multiplied by the number of hours of the specific activity type, giving 
the estimate for take by Level A harassment during that activity. For 
example, the Level A harassment isopleth for phocid pinnipeds during 
impact pile driving of 36-in steel piles is 2,323 meters, so Level B 
harassment estimates are multiplied by a factor of 0.14 (2,323/16,343 = 
0.14) to estimate take in the Level A harassment zone. All take by 
Level A harassment was conservatively calculated using isopleths from 
unattenuated source levels. Take by Level B harassment was calculated 
based on occurrence estimates for the area encompassed by the largest 
isopleth generated by unattenuated source levels (i.e., all of Passage 
Canal).
    Additionally, the shutdown zone for phocid pinnipeds was decreased 
compared to the calculated zone for pile driving activities that 
encompassed the public boat harbor approximately 1,500 meters away due 
to the possibility of harbor seals using the area as a haulout. The 
shutdown zone was reduced to 1,360-m for impact pile driving 42- and 
48-in pile sizes and DTH drilling of 48-in piles and the calculated 
take by Level A harassment has been doubled for this species.

                                                Table 7--Authorized Amount of Taking and Percent of Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Average     Take by Level   Take by Level                Percent of
                    Species                                   Stock                 group size   A harassment    B harassment    Total take     stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale................................  Hawaii DPS.......................          2.4               0              22           22           <1
                                                WNP DPS..........................  ...........               0               1            1           <1
                                                Mexico DPS.......................  ...........               0               2            2           <1
Dall's Porpoise...............................  Alaska...........................          4.3               9              36           45           <1
Killer Whale *................................  Alaska Resident..................           14               0             116          116            6
                                                GOA/Aleutian Islands/Bering Sea    ...........               0              29           29          4.9
                                                 Transient.
Harbor Seal...................................  Prince William Sound.............          3.5              40             170          210           <1
Steller Sea Lion..............................  Western U.S......................            4               0             218          218           <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
* AT-1 transient stock take calculation resulted in 0 takes, therefore no takes were requested or are authorized.


[[Page 19934]]

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses. NMFS regulations require applicants for incidental 
take authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting the activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks, and 
their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, as 
well as subsistence uses. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope, range). It further 
considers the likelihood that the measure will be effective if 
implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, and impact on 
operations.

Mitigation Measures

    TMC must follow mitigation measures as specified below:
     Ensure that construction supervisors and crews, the 
monitoring team, and relevant TMC staff are trained prior to the start 
of all pile driving and DTH activity, so that responsibilities, 
communication procedures, monitoring protocols, and operational 
procedures are clearly understood. New personnel joining during the 
project must be trained prior to commencing work;
     Employ Protected Species Observers (PSOs) and establish 
monitoring locations as described in the application, the Marine Mammal 
Monitoring Plan, and the IHA. The Holder must monitor the project area 
to the maximum extent possible based on the required number of PSOs, 
required monitoring locations, and environmental conditions. For all 
pile driving and removal at least one PSO must be used. The PSO will be 
stationed as close to the activity as possible;
     The placement of the PSOs during all pile driving and 
removal and DTH activities will ensure that the entire shutdown zone is 
visible during pile installation. Should environmental conditions 
deteriorate such that marine mammals within the entire shutdown zone 
will not be visible (e.g., fog, heavy rain), pile driving and removal 
must be delayed until the PSO is confident marine mammals within the 
shutdown zone could be detected;
     Monitoring must take place from 30 minutes prior to 
initiation of pile driving or DTH activity (i.e., pre-clearance 
monitoring) through 30 minutes post-completion of pile driving or DTH 
activity;
     Pre-start clearance monitoring must be conducted during 
periods of visibility sufficient for the lead PSO to determine that the 
shutdown zones indicated in Table 8 are clear of marine mammals. Pile 
driving and DTH may commence following 30 minutes of observation when 
the determination is made that the shutdown zones are clear of marine 
mammals;
     TMC must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a 30-second waiting 
period, then two subsequent reduced-energy strike sets. A soft start 
must be implemented at the start of each day's impact pile driving and 
at any time following cessation of impact pile driving for a period of 
30 minutes or longer; and
     If a marine mammal is observed entering or within the 
shutdown zones indicated in Table 8, pile driving and DTH must be 
delayed or halted. If pile driving is delayed or halted due to the 
presence of a marine mammal, the activity may not commence or resume 
until either the animal has voluntarily exited and been visually 
confirmed beyond the shutdown zone (Table 8) or 15 minutes have passed 
without re-detection of the animal;
     As planned by the applicant, in water activities will take 
place only between civil dawn and civil dusk when PSOs can effectively 
monitor for the presence of marine mammals; during conditions with a 
Beaufort Sea State of 4 or less; when the entire shutdown zone and 
adjacent waters are visible (e.g., monitoring effectiveness in not 
reduced due to rain, fog, snow, etc.). Pile driving may continue for up 
to 30 minutes after sunset during evening civil twilight, as necessary 
to secure a pile for safety prior to demobilization during this time. 
The length of the post-activity monitoring period may be reduced if 
darkness precludes visibility of the shutdown and monitoring zones.

Shutdown Zones

    TMC will establish shutdown zones for all pile driving activities. 
The purpose of a shutdown zone is generally to define an area within 
which shutdown of the activity will occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). 
Shutdown zones will be based upon the Level A harassment zone for each 
pile size/type and driving method where applicable, as shown in Table 
8.
    TMC will apply a minimum shutdown zone of 10-m for all pile driving 
related activities using a bubble curtain. For pile driving related 
activities without a bubble curtain, the minimum shutdown zone for 
cetaceans is 35-m and for pinnipeds is 15-m.
    Further, there will be a nominal 10-m shutdown zone for 
construction activity where acoustic injury is not the primary concern. 
This type of work could include (but is not limited to) the following 
activities: movement of the barge to the pile location; positioning of 
the pile on the substrate via a crane (i.e., stabbing the pile); and 
removal of the pile from the water column/substrate via a crane (i.e., 
deadpull). This 10-m zone applies for physical safety of marine mammals 
to prevent interaction with equipment. 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 8 
or 15 minutes have passed without re-detection of the animal. 
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 the harassment zone.
    All marine mammals will be monitored in the Level B harassment 
zones and throughout the area as far as visual monitoring can take 
place. If a marine mammal enters the Level B harassment zone, in-water 
activities will continue and the animal's presence within the estimated 
harassment zone will be documented.

[[Page 19935]]

    TMC will also establish shutdown zones for all marine mammals for 
which take has not been authorized or for which incidental take has 
been authorized but the authorized number of takes has been met. These 
zones are equivalent to the Level B harassment zones for each activity. 
If a marine mammal species not covered under this IHA enters the 
shutdown zone, all in-water activities will cease until the animal 
leaves the zone or has not been observed for at least 1 hour, and NMFS 
will be notified about species and precautions taken. Pile removal will 
proceed if the non-authorized species is observed to leave the Level B 
harassment zone or if 1 hour has passed since the last observation.
    If shutdown and/or clearance procedures will result in an imminent 
safety concern, as determined by TMC or its designated officials, the 
in-water activity will be allowed to continue until the safety concern 
has been addressed, and the animal will be continuously monitored.

                                                      Table 8--Shutdown Zones and Monitoring Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Minimum shutdown zone
                                                       ----------------------------------------------------------------------------------   Harassment
                       Activity                         Low-frequency (LF)  Mid-frequency (MF)    High-frequency                               zone
                                                             cetaceans           cetaceans        (HF) cetaceans      Phocid    Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barge movements, pile positioning, etc................                  10                  10                  10         10         10  ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Bubble Curtain in use (depths of 60-ft or less)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory Installation (temporary)..                  10                  10                  10         10         10           5,415
36-in steel pile, Vibratory Removal (temporary).......                  10                  10                  10         10         10           5,415
36-in steel pile, DTH Installation (temporary)........                 700                  35                 825        370         35       ** 16,345
36-in steel pile, Vibratory Installation (permanent)..                  10                  10                  10         10         10           5,415
36-in steel pile, Impact Installation (permanent).....               2,055              \1\ 80               2,400      1,100         80             635
36-in steel pile, DTH Installation (permanent)........                 800                  35               1,000        430         35       ** 16,345
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      No Bubble Curtain (depths greater than 60-ft)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory Installation (temporary)..                  35                  35                  35         15         15          11,660
36-in steel pile, Vibratory Removal (temporary).......                  35                  35                  35         15         15          11,660
42-in steel pile, Vibratory Installation..............                  35                  35                  35         15         15          16,345
48-in steel pile, Vibratory Installation..............                  35                  35                  35         15         15          16,345
42-in steel pile, Impact Installation.................               6,575             \1\ 260               7,830    * 1,360        260           3,745
48-in steel pile, Impact Installation.................               5,015             \1\ 200               5,975    * 1,360        200           3,745
36-in steel pile, DTH Installation (temporary)........               1,485                  70               1,770        795         70       ** 16,345
42-in steel pile, DTH Installation....................               1,770                  70               2,055        925         70       ** 16,345
48-in steel pile, DTH Installation....................               5,050                 200               6,015    * 1,360        200       ** 16,345
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For phocids (harbor seals) only, the Level A shutdown zone will be reduced to 1,360 m for impact pile driving of 42- and 48-in piles and DTH drilling
  of 48-in piles to exclude the Whittier Public Boat Harbor.
** Differs from Table 5 Level B harassment zone for DTH because 18,479-m and 39,811-m extends longer than Passage Canal, so land masses will block sound
  transmission and distances will be truncated. It will also be impractical to monitor this whole zone outside of Passage Canal. Instead, DTH monitoring
  zone will be the entirety of the Passage Canal and equivalent to the largest Level B harassment zone.
\1\ TMC has elected to conservatively apply thresholds for HF cetaceans to killer whales for impact pile driving. This species is an infrequent visitor
  to Passage Canal and is often highly visible, allowing for easier application of more conservative shutdown zones. This measure will reduce potential
  impacts to the highly vulnerable AT-1 killer whale stock that is found in this region should they enter Passage Canal during the in-water work period.

Protected Species Observers

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

Pre-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 and monitoring zones for a period of 30 
minutes. The shutdown zone will be considered cleared when a marine 
mammal has not been observed within the zone for that 30-minute

[[Page 19936]]

period. If a marine mammal is observed within the shutdown zones listed 
in Table 8, pile driving activity will be delayed or halted. If work 
ceases for more than 30 minutes, the pre-activity monitoring of the 
shutdown zones will commence. A determination that the shutdown zone is 
clear must be made during a period of good visibility (i.e., the entire 
shutdown zone and surrounding waters must be visible to the naked eye).

Soft-Start Procedures

    Soft-start procedures provide additional protection to marine 
mammals by providing warning and/or giving marine mammals a chance to 
leave the area prior to the hammer operating at full capacity. For 
impact pile driving, contractors will be required to provide an initial 
set of three strikes from the hammer at reduced energy, followed by a 
30-second waiting period, then two subsequent reduced-energy strike 
sets. Soft-start 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.

Bubble Curtain

    A bubble curtain must be employed during all pile installation and 
removal in depths of 60 ft or less. The bubble curtain must be deployed 
in manner guaranteed to distribute air bubbles around 100 percent of 
the piling perimeter for the full depth of the water column. The lowest 
bubble ring must be in contact with the mudline for the full 
circumference of the ring. The weights attached to the bottom ring must 
ensure 100 percent mudline contact. No parts of the ring or other 
objects may prevent full mudline contact. Air flow to the bubblers must 
be balanced around the circumference of the pile.
    Based on our evaluation of the applicant's measures, as well as 
other measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means effecting the least practicable 
impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance.

Monitoring and Reporting

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

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
conditions in this section, the Monitoring Plan, and this IHA. Marine 
mammal monitoring during pile driving activities will be conducted by 
PSOs meeting NMFS' the following requirements:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods will be used;
     At least one PSO will have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator will be designated. The lead 
observer will be required to have prior experience working as a marine 
mammal observer during construction.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary;
     TMC must employ up to four PSOs during all pile driving 
and DTH activities. A minimum of two PSOs (including the lead PSO) must 
be assigned to the active pile driving or DTH location to monitor the 
shutdown zones and as much of the Level B harassment zones as possible.
     TMC must establish the following monitoring locations with 
the best views of monitoring zones as described in the IHA and Marine 
Mammal Monitoring Plan.
     Two to four PSOs will be onsite during in-water activities 
associated with the Whittier Head of the Bay Cruise Ship Dock Project, 
likely stationed in the following locations PSOs will likely be located 
at Station 1: stationed just to the south of the site on the shore, 
Station 2: stationed off Depot Road near the freight loading dock, 
Station 3: stationed along the shoreline northeast of the Emerald Cove 
Trailhead, and Station 4: stationed on a boat triangulating an area 
between Emerald Island, the north shore of Passage Canal, southeast 
towards

[[Page 19937]]

Gradual Point, and back southwest toward Trinity Point and Emerald 
Island as shown in Figure 8 of the Marine Mammal Monitoring Plan. All 
PSOs will have access to high-quality binoculars, range finders to 
monitor distances, and a compass to record bearing to animals as well 
as radios or cells phones for maintaining contact with work crews.
    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.
    TMC shall conduct briefings between construction supervisors and 
crews, PSOs, TMC staff prior to the start of all pile driving 
activities, and when new personnel join the work. These briefings will 
explain responsibilities, communication procedures, marine mammal 
monitoring protocol, and operational procedures.

Acoustic Monitoring

    Acoustic monitoring must be conducted in accordance with the 
Acoustic Monitoring Plan. TMC must conduct hydroacoustic monitoring of 
two (one 36-in and one 48-in) piles each from different locations 
during DTH drilling.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities, or 60 days prior to a requested date of issuance from any 
future IHAs for projects at the same location, whichever comes first. 
The report will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including the number and type of piles driven or 
removed and by what method (i.e., impact, vibratory, or DTH) and the 
total equipment duration for vibratory removal or DTH for each pile or 
hole or total number of strikes for each pile (impact driving);
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information:
    [cir] Name of PSO who sighted the animal(s) and PSO location and 
activity at the time of sighting;
    [cir] Time of sighting;
    [cir] Identification of the animal(s) (e.g., genus/species, lowest 
possible taxonomic level, or unidentifiable), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    [cir] Distance and bearing of each marine mammal observed relative 
to the pile being driven for each sightings (if pile driving was 
occurring at time of sighting);
    [cir] Estimated number of animals (min/max/best estimate);
    [cir] Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, sex class, etc.);
    [cir] Animal's closest point of approach and estimated time spent 
within the harassment zone; and
    [cir] Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching).
     Number of marine mammals detected within the harassment 
zones and shutdown zones; by species;
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensured, and resulting changes in behavior of the 
animal(s), if any; and
     If visibility degrades to where PSO(s) cannot view the 
entire harassment zones, additional PSOs may be positioned so that the 
entire width is visible, or work will be halted until the entire width 
is visible to ensure that any humpback whales entering or within the 
harassment zone are detected by PSOs.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Acoustic Monitoring Plan

    The report must include:
     Type and size of pile being driven, substrate type, method 
of driving during recordings (including hammer model and energy 
setting(s)), total pile driving duration, and water depth at the pile;
     Whether a sound attenuation device is used and, if so, a 
detailed description of the device and the duration of its use per 
pile;
     Number of strikes and strike rate, depth of substrate to 
penetrate; pulse duration and mean, median, and maximum sound levels 
(dB re: 1 [micro]Pa); root mean square sound pressure level (SPLrms), 
peak sound pressure level (SPLpeak), cumulative sound exposure level 
(SELcum), and single strike exposure sound level (SEL s-s);
     One-third octave band spectrum and power spectral density 
plot for each pile monitored; and
     Environmental data, including but not limited to, the 
following: wind speed and direction, air temperature, humidity, surface 
water temperature, water depth, wave height, weather conditions, and 
other factors that could contribute to influencing the airborne and 
underwater sound levels (e.g., aircraft, boats, etc.).

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder must 
immediately cease the specified activities and report the incident to 
the Office of Protected Resources (OPR) 
([email protected]), NMFS and to the Alaska Regional 
Stranding Coordinator as soon as feasible. If the death or injury was 
clearly caused by the specified activity, TMC must immediately cease 
the specified activities until NMFS is able to review the circumstances 
of the incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS. The 
report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;

[[Page 19938]]

     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).
    To avoid repetition, our analysis applies to all species listed in 
Table 1 for which take could occur, given that NMFS expects the 
anticipated effects of the pile driving/removal and DTH on different 
marine mammal stocks to be similar in nature. Where there are 
meaningful differences between species or stocks, or groups of species, 
in anticipated individual responses to activities, impact of expected 
take on the population due to differences in population status, or 
impacts on habitat, NMFS has identified species-specific factors to 
inform the analysis.
    Pile driving and DTH 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 activities. 
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. 
Further, no take by Level A harassment is anticipated for humpback 
whales, killer whales, or Steller sea lion due to the application of 
planned mitigation measures, such as shutdown zones that encompass the 
Level A harassment zones for these species and the rarity of these 
species near the action area. The potential for harassment would be 
minimized through the construction method and the implementation of the 
planned mitigation measures (see Mitigation section).
    Take by Level A harassment is authorized for two species (Dall's 
porpoise and harbor seal) as the Level A harassment zones exceed the 
size of the shutdown zones for specific construction scenarios. 
Additionally, these species could be found more often near the action 
area and are cryptic in nature. Therefore, there is the possibility 
that an animal could enter a Level A harassment zone without being 
detected, and remain within that zone for a duration long enough to 
incur PTS. Level A harassment of these species is authorized to be 
conservative. Any take by Level A harassment is expected to arise from, 
at most, a small degree of PTS (i.e., minor degradation of hearing 
capabilities within regions of hearing that align most completely with 
the 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 PTS.
    Further, the amount of take by Level A harassment authorized is 
very low for both marine mammal stocks and species. If hearing 
impairment occurs, it is most likely that the affected animal will lose 
only a few decibels in its hearing sensitivity. Due to the small degree 
anticipated, any PTS potential incurred will 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. 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 will therefore not likely impact reproduction or 
survival of any individual marine mammal, let alone adversely affect 
rates of recruitment or survival of the species or stock.
    The Level A harassment zones identified in Table 5 are based upon 
an animal exposed to pile driving or DTH up to four piles per day. 
Given the short duration to impact drive or vibratory install or 
extract, or use DTH drilling on each pile, and breaks between pile 
installations (to reset equipment and move piles into place), an animal 
will have to remain within the area estimated to be ensonified above 
the Level A harassment threshold for multiple hours. This is highly 
unlikely give marine mammal movement in the area. If an animal was 
exposed to accumulated sound energy, the resulting PTS will likely be 
small (e.g., PTS onset) at lower frequencies where pile driving energy 
is concentrated, and unlikely to result in impacts to individual 
fitness, reproduction, or survival.
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. For all species and stocks, take will 
occur within a limited, confined area (adjacent to the project site) of 
the stock's range. Level A and Level B harassment will be reduced to 
the level of least practicable adverse impact through use of mitigation 
measures described herein. Further, the amount of take authorized is 
extremely small when compared to stock abundance.
    Behavioral responses of marine mammals to pile driving, pile 
removal, and DTH at the sites in the Passage Canal are expected to be 
mild, short term, and temporary. Marine mammals within the Level B 
harassment zones may not show any visual cues they are disturbed by 
activities or they could become alert, avoid the area, leave the area, 
or display other mild responses that are not observable such as changes 
in vocalization patterns. Given that pile driving, pile removal, and 
DTH will occur for only a portion of the project's duration, any 
harassment occurring will be temporary. Additionally, many of the 
species present in region will only be present temporarily based on 
seasonal patterns or during transit between other habitats. These 
temporary present species will be exposed to even smaller

[[Page 19939]]

periods of noise-generating activity, further decreasing the impacts.
    For all species, there are no known Biologically Important Areas 
(BIAs) near the project area that will be impacted by TMC's planned 
activities. While southcentral Alaska is considered an important area 
for feeding humpback whales between March and May (Ellison et al., 
2012), it is not currently designated as critical habitat for humpback 
whales (86 FR 21082, April 21, 2021).
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat will 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 will 
have only minor, short-term effects on individuals. The specified 
activities are not expected to impact rates of recruitment or survival 
and will 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 the species or stock through 
effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Authorized Level A harassment will be very small amounts 
and of low degree;
     Level A harassment takes of only Dall's porpoise and 
harbor seals;
     For all species, the Passage Canal is a very small and 
peripheral part of their range;
     The intensity of anticipated takes by Level B harassment 
is relatively low for all stocks. Level B harassment will 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 the 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 will 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
     TMC will implement mitigation measures including soft-
starts 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 PTS.
    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 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 plans to authorize is below one-third of 
the estimated stock abundance for all species (in fact, take of 
individuals is less than five percent of the abundance of the affected 
stocks, see Table 7). This is likely a conservative estimate because we 
assume all takes are of different individual animals, which is likely 
not 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.
    Additionally, the most recent estimate for the Alaska stock of 
Dall's porpoise was 13,110 animals; however this number just accounts 
for a portion of the stock's range. Therefore, the 45 takes of this 
stock planned for authorization is believed to be an even smaller 
portion of the overall stock abundance.
    Based on the analysis contained herein of the planned activity 
(including the mitigation and monitoring measures) and the anticipated 
take of marine mammals, NMFS finds that small numbers of marine mammals 
will be taken relative to the population size of the affected species 
or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    The Alutiiq and Eyak people of Prince William Sound traditionally 
harvested marine mammals, however the last recorded harvest of marine 
mammals in Whittier was in 1990, where it was reported that seven 
marine mammals were harvested (ADF&G 2022b). Other Prince William Sound 
coastal communities such as Cordova, Chenega, and Tatitlek report 
recent subsistence harvest or use of marine mammals. The most recent 
report of harbor seal and Steller sea lion harvest was reported in 
Tatitlek in 2014 (ADF&G 2022b).
    Subsistence hunters in Prince William Sound report having to travel 
farther from their home communities to be successful when harvesting 
marine mammals (Keating et al. 2020). However, their range was not 
reported to extend into Passage Canal, as all three communities are 
located at least 60 miles away by boat (Fall and Zimpelman 2016). The 
planned project is not likely to adversely impact the availability of 
any marine mammal species or stocks that are commonly used for 
subsistence purposes or to impact subsistence harvest of marine mammals 
in the region because:
     Construction activities are localized and temporary;
     Mitigation measures will be implemented to minimize 
disturbance of marine mammals in the action area; and,

[[Page 19940]]

     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 mitigation and monitoring 
measures, NMFS has determined that there will not be an unmitigable 
adverse impact on subsistence uses from TMC's planned activities.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species, in this case with the Alaska Regional 
Office.
    NMFS is authorizing take of Western U.S. Steller Sea Lion, Western 
North Pacific Humpback whale, and the California/Oregon/Washington 
Humpback whale, which are listed under the ESA.
    The Permit and Conservation Division completed a Section 7 
consultation with the Alaska Regional Office for the issuance of this 
IHA. The Alaska Regional Office's biological opinion states that the 
action is not likely to jeopardize the continued existence of the 
listed species.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has determined 
that the issuance of the IHA qualifies to be categorically excluded 
from further NEPA review.

Authorization

    As a result of these determinations, NMFS issues an IHA to TMC for 
conducting Whittier head of the Bay Cruise Ship Dock project in 
Whittier, Alaska, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. The IHA can be 
found at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-turnagain-marine-constructions-cruise-dock-construction.

    Dated: March 29, 2023.
Catherine Marzin,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2023-06895 Filed 4-3-23; 8:45 am]
BILLING CODE 3510-22-P