Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Whittier Head of the Bay Cruise Dock Project in Whittier, Alaska, 9227-9249 [2023-02997]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 29 (Monday, February 13, 2023)]
[Notices]
[Pages 9227-9249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-02997]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC705]


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

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

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

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SUMMARY: NMFS has received a request from Turnagain Marine Construction 
(TMC) for authorization to take marine mammals incidental to the cruise 
dock construction project in Whittier, Alaska. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an incidental harassment authorization (IHA) to 
incidentally take marine mammals during the specified activities. NMFS 
is also requesting comments on a possible one-time, 1 year renewal that 
could be issued under certain circumstances and if all requirements are 
met, as described in Request for Public Comments at the end of this 
notice. NMFS will consider public comments prior to making any final 
decision on the issuance of the requested MMPA authorization and agency 
responses will be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than March 
15, 2023.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service and should be submitted via email to 
[email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments, including all attachments, must 
not exceed a 25-megabyte file size. All comments received are a part of 
the public record and will generally be posted online at 
www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act without change. All personal identifying 
information (e.g., name, address) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

FOR FURTHER INFORMATION CONTACT: 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#active-authorizations. 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

[[Page 9228]]

availability of the species or stocks for taking for certain 
subsistence uses (referred to in shorthand as ``mitigation''); and 
requirements pertaining to the mitigation, monitoring and reporting of 
the takings are set forth. The definitions of all applicable MMPA 
statutory terms cited above are included in the relevant sections 
below.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for 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 
preliminarily determined that the issuance of the proposed IHA 
qualifies to be categorically excluded from further NEPA review. We 
will review all comments submitted in response to this notice prior to 
concluding our NEPA process or making a final decision on the IHA 
request.

Summary of Request

    On 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. 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 Proposed Activity

Overview

    TMC proposes to construct the Whittier Head of the Bay cruise ship 
dock project in the Passage Canal in Whittier, Alaska. The proposed 
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 72 36-inch (in) (0.91 
meter (m)) temporary steel pile guides and installation of 36 36-in, 16 
42-in (1.1-m), and 20 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 would be used during all activities that 
fall below the 60-ft. 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.

Dates and Duration

    The proposed IHA would be effective from April 1, 2023 through 
March 31, 2024. The total expected work duration would be approximately 
321 hours over 129 nonconsecutive days (an estimated 45 days of DTH, 59 
days of vibratory pile installation, and 24.5 days of impact pile 
driving). An estimated 156 hours over 58.5 days would use a bubble 
curtain, and 165 hours over 70 days would be unattenuated. The 
construction timeline takes into account the mobilization of materials 
and potential delays due to delayed material deliveries, equipment 
maintenance, inclement weather, and shutdowns. TMC plans to conduct all 
work during daylight hours.

Specific Geographic Region

    The proposed activity will occur in the head of Passage Canal, a 
bay of Prince William Sound in South Central Alaska in Whittier, Alaska 
(Figure 1-2). This proposed cruise ship dock would be approximately one 
kilometer (0.75 miles) northwest of downtown Whittier. Passage Canal is 
an approximately 12-mile-long (19.3 kilometer (km)) fjord that measures 
less than 2 miles (3.2-km) across from shore to shore at its widest 
point and reaches depths over 1,000-ft (304.8-m) at its entrance near 
Decision Point and Blackstone Bay. Depths at the head of Passage Canal 
are shallower, approximately 100 to 200-ft (30.48 to 60.96-m).

[[Page 9229]]

[GRAPHIC] [TIFF OMITTED] TN13FE23.001

Detailed Description of the Specified Activity

    TMC proposes to install and remove 72 steel piles to guide the 72 
permanent piles into place to support the cruise ship berth and 
floating dock. The piles would be installed using three methods over 
129 days, which incorporated buffer days to account for unforeseen 
interruptions. These methods include vibratory pile installation and 
removal, impact pile driving, and DTH drilling (see Table 1).
    Pile templates would be constructed using temporary pilings 
vibrated into position. Three or four temporary 36-in diameter pilings 
may be needed for each template. Most temporary piles would be vibrated 
into place; however, up to 36 of these may need to make use of a DTH 
drill in locations where the bedrock is shallow. For each 36-in 
temporary pile, an estimated 2 cubic yards (CY) (1.53 cubic meter) of 
drill cuttings would be produced. Using the templates as guides to 
position the permanent piling, the piling would be vibrated into dense 
material. The piling would then be driven to tip elevation using an 
impact hammer. Once the piles achieve the tip elevation, a DTH hammer 
would be placed inside the piling and a shaft would be drilled into the 
bedrock. The rock shaft would be filled with concrete to anchor the 
pile to the bedrock. The 36 permanent 36-in diameter steel piles 
supporting the approach trestle would be vibrated to at least 24 feet 
(7.31-m) below the mudline. If the soil depth is less than 24 feet, the 
piles would then be drilled at least 10 feet (3.05-m) deep into bedrock 
with a DTH hammer and bit. For each 36-in permanent pile, an estimated 
10 CY (7.65 cubic meter) of drill cuttings would be produced. The 16 
permanent 42-in diameter and 20 permanent 48-in diameter steel piles 
would be vibrated through the soil layer to bedrock to support other 
dock components. A 38-in diameter shaft would be drilled through the 
42- and 48-in diameter into the bedrock with the DTH hammer and bit, 
and then filled with concrete to a depth of at least 25 feet (7.62-m) 
to anchor the piles.
    TMC divides the work into two areas by depth; activities occurring 
within the 60-ft. isobath or shallower and, those occurring in depths 
greater than the 60-ft. isobath. The 36 36-in permanent piles 
supporting the approach trestle and the 36 36-inch temporary piles used 
as template guides for them would fall within the 60-ft. isobath. The 
16 42-inch and 20 48-inch for the mooring trestle and dolphins (and the 
36 36-inch temporary piles used as template guides for these) would 
fall within waters deeper than the 60-ft. isobath. A bubble curtain 
would be deployed at a depth of 60 feet (18.3-m) and would be used 
during all activities that fall within the 60-ft. isobath.
    Additional actions occurring under the proposed action that are not 
anticipated to generate in-water noise resulting in marine mammal 
harassment include vessels to support construction and out of water 
dock components. NMFS does not expect, that these ancillary activities 
will harm or harass marine mammals and no incidental takes are expected 
as a result of these activities. Therefore, these activities are not 
discussed further in this document.

                                Table 1--Pile Installation Methods and Durations
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                                           Number of      Duration/impacts per     Piles drive/
           Pile size, method                 piles                pile                  day       Estimated days
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36-in steel pile, Vibratory                         72  10 min..................               4              18
 Installation (temporary).
36-in steel pile, Vibratory Removal                 72  10 min..................               4              18
 (temporary).
36-in steel pile, Vibratory                         36  15 min..................               4               9
 Installation (permanent).
42-in steel pile, Vibratory                         16  15 min..................               4               4
 Installation.
48-in steel pile, Vibratory                         20  15 min..................               2              10
 Installation.

[[Page 9230]]

 
36-in steel pile, Impact Installation               36  1800 strikes............               4               9
 (permanent).
42-in steel pile, Impact Installation.              16  2400 strikes............               3             5.5
48-in steel pile, Impact Installation.              20  2400 strikes............               2              10
36-in steel pile, DTH Installation                  36  60 min..................               4               9
 (temporary).
36-in steel pile, DTH Installation                  36  150 min.................               2              18
 (permanent).
42-in steel pile, DTH Installation....              16  150 min.................               2               8
48-in steel pile, DTH Installation....              20  150 min.................               2              10
----------------------------------------------------------------------------------------------------------------

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

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, 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 2 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR), where known. PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS' 
SARs). While no serious injury or mortality is expected to occur, 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 2 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 2--Species Likely Impacted by the Specified Activities
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                                                                                         ESA/MMPA status;    Stock abundance  (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenopteridae (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).
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                                                         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):

[[Page 9231]]

 
    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's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ 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.

    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 DPSs. 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's 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 proposed 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 2 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur, and we have proposed 
authorizing it. All species that could potentially occur in the 
proposed survey areas are included in Table 5 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.
    In addition, the northern sea otter (Enhydra lutris kenyoni) may be 
found in the Passage Canal. However, northern sea otters are managed by 
the U.S. Fish and Wildlife Service and are not considered further in 
this document.

Humpback Whale

    The humpback whale is found worldwide in all oceans. Prior to 2016, 
humpback whales were listed under the ESA as an endangered species 
worldwide. Following a 2015 global status review (Bettridge et al., 
2015), NMFS established 14 Distinct Population Segments (DPS) with 
different listing statuses (81 FR 62259; September 8, 2016) pursuant to 
the ESA. Humpback whales found in the project area are predominantly 
from the three DPSs that are present in Alaska.
    Whales from the Western North Pacific (WNP), Mexico, and Hawaii 
DPSs overlap on feeding grounds off Alaska and are not visually 
distinguishable. Members of different DPSs are known to intermix on 
feeding grounds; therefore, all waters off the coast of Alaska should 
be considered to have ESA-listed humpback whales. Based on an analysis 
of migration between winter mating/calving areas and summer feeding 
areas using photo-identification, Wade (2021) concluded that the 
humpback whales feeding in Alaskan waters belong primarily to the 
recovered Hawaii DPS (89 percent), with small contributions from the 
threatened Mexico DPS (11 percent) and the endangered WNP DPS (0.4 
percent; rounded to 1 percent in NMFS 2021a).
    The DPSs of humpback whales that were identified through the ESA 
listing process do not equate to the existing MMPA stocks. The updated 
stock delineations for humpback whales under the MMPA are currently out 
for public review in the draft 2022 SAR's, as mentioned above. Until 
this review is complete, NMFS considers humpback whales in Southeast 
Alaska to be part of the Central North Pacific stock (Muto et al., 
2021).
    Humpback whales are found throughout Southcentral Alaska in a 
variety of marine environments, including open-ocean, near-shore 
waters, and areas within strong tidal currents (Dahlheim et al., 2009). 
Humpback whales generally arrive in Southeast Alaska in March and 
return to their wintering grounds in November. Some humpback whales 
depart late or arrive early to feeding grounds, and therefore the 
species can occur in the Southeast Alaska region year-round (Straley, 
1990, Straley et al., 2018). Across the region, there have been no 
recent estimates of humpback whale density.
    NMFS identified a portion of Prince William Sound as a Biologically 
Important Area (BIA) for humpback whales for feeding during the months 
of September through December; however, the proposed action area is 
northwest of the boundaries of the BIA (NMFS 2022c). BIAs are spatial 
and temporal boundaries identified for certain marine mammal species 
where populations are known to concentrate for specific behaviors such 
as migration, feeding, or breeding. This BIA was identified due to 
boat-based surveys that observed high number of humpback whales feeding 
(mainly on Pacific herring) in the area (Ferguson et al., 2015). 
Humpback whale BIAs helped to inform the critical habitat designation 
finalized by NMFS in 2021 (86 FR 21082, April 21, 2021). Much of Prince 
William Sound is also within humpback whale critical habitat, and 
material and equipment barges' routes would transit through critical 
habitat on the way to the project site. However, the proposed project 
is approximately 17 km west of the boundaries of the critical habitat, 
and

[[Page 9232]]

the ensonified action area extends through Passage Canal, but ends 
about 3.5 kilometers west of the critical habitat boundary.
    In Prince William Sound and Passage Canal, humpback whales are 
traditionally observed during seasons of high prey concentration, May 
through September (Witteveen et al., 2011; SolsticeAK 2022). However, 
feeding humpback whales' presence in the Gulf of Alaska has also been 
correlated closely with peak herring abundance, which occurs in the 
late fall and early winter. It has been suggested that some whales 
remain longer in northern waters to maximize food consumption prior to 
migrating south to breeding grounds in the winter, and a few may skip 
migration altogether (Straley et al., 2018). Therefore, humpbacks may 
be present year-round in Prince William Sound, but are less common 
during the late winter and early spring.
    While sightings of humpbacks are fairly common in Prince William 
Sound, they are less common in Passage Canal (SolsticeAK 2022). No 
humpback whales were observed within Passage Canal during the Whittier 
Ferry Terminal Modification Project in April 2020 (Leonard and Wisdom 
2020).

Dall's Porpoise

    All Dall's porpoises in Alaska are members of the Alaska stock. 
This species can be found in offshore, inshore, and nearshore habitats. 
Dall's porpoises are widely distributed across the North Pacific Ocean 
and are one of the most common cetaceans in the Gulf of Alaska (Rone et 
al., 2017). Surveys conducted in the Gulf of Alaska from 2009 to 2015 
indicate that Dall's porpoises inhabit all strata on the continental 
shelf, slope, and pelagic waters with the greatest densities occurring 
in deeper inshore and slope habitats (Rone et al., 2017).
    From data collected during surveys conducted from 2007 to 2015, 
Dall's porpoise presence in Prince William Sound varied based on 
season. They were most dispersed throughout Prince William Sound in the 
summer months but tended towards deeper waters in the middle of the 
Sound, away from shorelines. In the fall and winter, they were more 
often observed in the periphery of Prince William Sound with 
concentrations in bay areas, likely following herring shoals towards 
their overwintering areas. Their distribution was most concentrated in 
the spring, with one major activity center in eastern Prince William 
Sound. These porpoises were not typically found in shallow habitats or 
confined fjords like that of Passage Canal, preferring open water 
escape routes where they are able to use quick swimming techniques to 
evade predators such as killer whales (Moran et al., 2018).
    Dall's porpoises are frequently observed near the entrance of 
Passage Canal but not often seen far down the canal near Whittier 
(DOT&PF 2019). Correspondence with local tour boat captains confirmed 
there are occasional sightings of Dall's porpoise in Passage Canal, but 
they are more often seen farther out towards Prince William Sound in 
Well's Passage (SolsticeAK 2022). The Whittier Ferry Terminal 
Modification Project Marine Mammal Monitoring Report indicated that 
there was one sighting of a group of six Dall's porpoises in Passage 
Canal during construction work in April 2020 (Leonard and Wisdom 2020).

Killer Whale

    Killer whales occur along the entire Alaska coast, in British 
Columbia and Washington inland waterways, and along the outer coasts of 
Washington, Oregon, and California (NMFS, 2016). The three stocks that 
are most likely to occur in Prince William Sound are the southern 
Alaska Resident stock, Gulf of Alaska/Aleutian Islands/Bering Sea 
Transient stock, and the AT1 Transient stock (Muto et al., 2022).
    There are three distinct ecotypes, or forms, of killer whales 
recognized: Resident, Transient, and Offshore. The three ecotypes 
differ morphologically, ecologically, behaviorally, and genetically. 
Both residents and transients are common in a variety of habitats and 
all major waterways, including protected bays and inlets. There does 
not appear to be strong seasonal variation in abundance or distribution 
of killer whales, but there was substantial variability between years 
(Dahlheim et al., 2009). Spatial distribution has been shown to vary 
among the different ecotypes, with resident and, to a lesser extent, 
transient killer whales more commonly observed along the continental 
shelf, and offshore killer whales more commonly observed in pelagic 
waters (Rice et al., 2017).
    In the Gulf of Alaska, the offshore killer whale ecotype is found 
in pelagic waters off the Aleutian Islands to California and mainly 
prey on sharks; the resident ecotype (southern Alaska residents) ranges 
from Kodiak Island to Southeast Alaska and prefer to eat fish; and two 
different transient populations (Gulf of Alaska transients and AT1 
transients) prefer marine mammals are most often found near the 
Hinchinbrook Entrance and Montague Strait (Myers et al., 2021). A 
tagging study focused on resident killer whale movements in Prince 
William Sound found that killer whales' favored use areas were highly-
seasonal and pod specific, likely timed with seasonal salmon returns to 
spawning streams (Olsen et al., 2018).
    With the exception of the AT1 Transient stock, the populations that 
are known to occur in Prince William Sound are not strategic or 
depleted under the MMPA. Long-term studies of pods belonging to the 
southern Alaska resident stock in the Gulf of Alaska indicate these 
populations are increasing at an estimated growth rate of approximately 
3.4 percent (Matkin et al., 2014). However, both resident and transient 
killer whales were significantly impacted by the 1989 Exxon Valdez Oil 
spill. Prior to the spill, the resident AB pod consisted of 36 members 
and from 1989 to 1990, 14 whales disappeared from the pod. The AB pod 
is considered recovering; however, due to slow reproduction rates only 
28 individuals were observed in 2005 (Exxon Valdez Oil Spill Trustee 
Council 2021). The AT1 Transient stock also experienced high mortality 
following the oil spill, as 11 of the original 22 individuals 
disappeared between 1989 and 1992. The AT1 stock currently numbers only 
seven individuals (Muto et al., 2021).
    Results from the Olsen et al., (2018) satellite tagging surveys in 
Prince William Sound from 2006 to 2014 revealed several core use areas 
for resident killer whales based on pod and season. Most resident pods 
primarily concentrated at the southern end of Prince William Sound in 
Hinchinbrook Entrance during the summer and Montague Strait in the late 
summer and fall. A few of the pods were observed making trips to deeper 
glacial fjords including Passage Canal, but these areas did not appear 
to be an important focus area for the pods. The AD16 pod (estimated 9 
animals) and AK pod (estimated 19 animals) were the most frequently 
observed in the northern glacial fjords of the sound (Muto et al., 
2022; Olsen et al., 2018).
    Additionally, a 27-year photo identification study in Prince 
William Sound and Kenai Fjords surveyed both populations of transient 
killer whales. The study found that the AT1 transients had higher site 
fidelity to the area, while the Gulf of Alaska transients had a higher 
exchange of individuals (Matkin et al., 2012). Resighting data 
indicated that the AT1 population are resident to the area and the Gulf 
of Alaska transients are part of a larger population with a more 
extensive range. Throughout the study, survival estimates for both 
populations was generally high, but there was significant

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population reduction in the AT1 transient after the Exxon Valdez oil 
spill (Matkin et al., 2012). There was no detectable decline in the 
larger Gulf of Alaska transient population after the oil spill (Matkin 
et al., 2012).
    Consultation with marine wildlife tour operators confirmed that 
killer whales are often observed in Prince William Sound, but less 
commonly seen in Passage Canal (SolsticeAK 2022). There are prey 
resources (marine mammals, salmon, etc.) present that may draw killer 
whales to the area, particularly during salmon runs from June through 
October, but concentration of prey is not likely large enough to keep 
killer whales in the area for long. During the Whittier Ferry Terminal 
Modification Project in April 2020, there were no observations of 
killer whales in the action area (Leonard and Wisdom 2020).

Harbor Seal

    Harbor seals inhabit coastal and estuarine waters off Alaska and 
are one of the most common marine mammals in Alaska. They haul out on 
rocks, reefs, beaches, and drifting glacial ice. They are opportunistic 
feeders and often adjust their distribution to take advantage of 
locally and seasonally abundant prey, feeding in marine, estuarine, and 
occasionally fresh waters (Womble et al., 2009, Allen and Angliss, 
2015). Harbor seals are generally non-migratory and, with local 
movements associated with such factors as tide, weather, season, food 
availability and reproduction. They deviate from other pinniped species 
in that pupping may occur on a wide variety of haul-out sites rather 
than particular major rookeries (ADF&G 2022).
    Distribution of the Prince William Sound stock, the only stock 
considered in this application, range from Elizabeth Island off the 
southwest tip of the Kenai Peninsula to Cape Fairweather, including 
Prince William Sound, the Copper River Delta, Icy Bay, and Yakutat Bay 
(Muto et al., 2022). The Prince William Sound stock of harbor seals are 
commonly sighted residents and can occur on any given day in the action 
area, although they tend to be more abundant during the fall months 
(Womble and Gende 2013).
    Communication with Whittier tour operators indicated that harbor 
seals are often seen in Passage Canal, but generally do not gather near 
Whittier in large numbers (SolsticeAK 2022). They sometimes haul out at 
the Whittier Public Boat Harbor around 1,500 meters away (DOT&PF 2019). 
The Marine Mammal Monitoring Report from the Whittier Ferry Terminal 
Modification reported 10 sightings of 13 harbor seals during the April 
2020 construction period, which agrees with the tour operators' 
accounts (commonly seen, generally individual animals rather than 
groups) (Leonard and Wisdom 2020).

Steller Sea Lion

    Steller sea lions were listed as threatened range-wide under the 
ESA on November 26, 1990 (55 FR 49204). Steller sea lions were 
subsequently partitioned into the western and eastern Distinct 
Population Segments (DPSs; western and eastern stocks) in 1997 (62 FR 
24345; May 5, 1997). The eastern DPS remained classified as threatened 
until it was delisted in November 2013. The western DPS (those 
individuals west of the 144[deg] W longitude or Cape Suckling, Alaska) 
was upgraded to endangered status following separation of the DPSs, and 
it remains endangered today. There is regular movement of both DPSs 
across this 144[deg] W longitude boundary (Jemison et al., 2013) 
however, due to the distance from this DPS boundary, it is likely that 
only western DPS Steller sea lions are present in the project area. 
Therefore, animals potentially affected by the project are assumed to 
be part of the western DPS. Sea lions from the eastern DPS, are not 
likely to be affected by the proposed activity and are not discussed 
further.
    Steller sea lions do not follow traditional migration patterns, but 
will move from offshore rookeries in the summer to more protected 
haulouts closer to shore in the winter. They use rookeries and haulouts 
as resting spots as they follow prey movements and take foraging trips 
for days, usually within a few miles of their rookery or haulout. They 
are generalist marine predators and opportunistic feeders based on 
seasonal abundance and location of prey. Steller sea lions forage in 
nearshore as well as offshore areas, following prey resources. They are 
highly social and are often observed in large groups while hauled out 
but alone or in small groups when at sea (NMFS 2022f).
    Steller sea lions are distributed throughout Southcentral Alaska, 
with patterns loosely correlated to aggregations of spawning and 
migrating prey species (Sinclair and Zeppelin 2002; Sinclair et al., 
2013). Haulout sites in Southcentral Alaska, at and west of Cape 
Suckling, were documented through aerial surveys (Fritz et al., 2013). 
Although there are no documented haulouts or rookeries within Passage 
Canal, a small number of Steller sea lions have been reported hauling 
out year-round on a mooring buoy in Shotgun Cove (SolsticeAK 2022; 
DOT&PF 2019).
    Steller sea lions occur year-round in the program action area. 
Steller sea lions are drawn to fish processing plants and high forage 
value areas such as anadromous streams. Passage Canal has several 
anadromous streams that support salmon species and one fish processing 
plant with an Alaska Department of Environmental Conservation (ADEC) 
permitted outfall that also attracts Steller sea lions (ADF&G 2022a). 
There were 9 Steller sea lion groups (representing about 27 
individuals) sighted during marine mammal monitoring of the Whittier 
Ferry Terminal Modification Project in April 2020. Groups ranged from 
one to seven animals. Steller sea lions were most often observed 
floating and/or swimming at the surface. Sightings occurred over a 
period of 6 days and approximately 86 hours of monitoring time (Leonard 
and Wisdom 2020).
    Critical habitat for Steller sea lions was designated by NMFS in 
1993 based on the following essential physical and biological habitat 
features: terrestrial habitat (including rookeries and haulouts 
important for rest, reproduction, growth, social interactions) and 
aquatic habitat (including nearshore waters around rookeries and 
haulouts, free passage for migration, prey resources, and foraging 
habitats) (58 FR 45269).
    The nearest rookery is Seal Rocks located in the Hinchinbrook 
Entrance between Hinchinbrook and Montague Islands, 124 kilometers (67 
nautical miles) southeast of the proposed berth site. The nearest major 
haulouts are Perry, approximately 44 kilometers (24 nautical miles) 
southeast of the proposed berth site and Dutch Group, approximately 52 
kilometers (28 nautical miles) east (Alaska Fisheries Science Center 
2022). Since the ensonified action area encompasses most of Passage 
Canal, it would intersect Steller sea lion designated critical habitat. 
Additionally, since most of Prince William Sound is within Steller sea 
lion critical habitat, material and equipment barges' routes would 
transit through critical habitat on the way to the project site.

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

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species have equal hearing capabilities (e.g., Richardson et al., 1995; 
Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect this, 
Southall et al. (2007, 2019) recommended that marine mammals be divided 
into hearing groups based on directly measured (behavioral or auditory 
evoked potential techniques) or estimated hearing ranges (behavioral 
response data, anatomical modeling, etc.). Note that no direct 
measurements of hearing ability have been successfully completed for 
mysticetes (i.e., low-frequency cetaceans). Subsequently, NMFS (2018) 
described generalized hearing ranges for these marine mammal hearing 
groups. Generalized hearing ranges were chosen based on the 
approximately 65 decibel (dB) threshold from the normalized composite 
audiograms, with the exception for lower limits for low-frequency 
cetaceans where the lower bound was deemed to be biologically 
implausible and the lower bound from Southall et al. (2007) retained. 
Marine mammal hearing groups and their associated hearing ranges are 
provided in Table 3.

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
                                                    Generalized hearing
                  Hearing group                           range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales)....  7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, toothed   150 Hz to 160 kHz.
 whales, beaked whales, bottlenose whales).
High-frequency (HF) cetaceans (true porpoises,    275 Hz to 160 kHz.
 Kogia, river dolphins, Cephalorhynchid,
 Lagenorhynchus cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true seals).  50 Hz to 86 kHz.
Otariid pinnipeds (OW) (underwater) (sea lions    60 Hz to 39 kHz.
 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., 2005; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section provides a discussion of the ways in which components 
of the specified activity may impact marine mammals and their habitat. 
The Estimated Take section later in this document includes a 
quantitative analysis of the number of individuals that are expected to 
be taken by this activity. The Negligible Impact Analysis and 
Determination section considers the content of this section, the 
Estimated Take section, and the Proposed Mitigation section, to draw 
conclusions regarding the likely impacts of these activities on the 
reproductive success or survivorship of individuals and whether those 
impacts are reasonably expected to, or reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.
    Acoustic effects on marine mammals during the specified activity 
can occur from impact pile driving, vibratory driving, and DTH. The 
effects of underwater noise from TMC's proposed activities have the 
potential to result in Level A or Level B harassment of marine mammals 
in the action area.

Description of Sound Source

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include vibratory pile removal, impact and vibratory pile driving, and 
drilling. The sounds produced by these activities fall into one of two 
general sound types: Impulsive and non-impulsive. Impulsive sounds 
(e.g., explosions, gunshots, sonic booms, impact pile driving) are 
typically transient, brief (less than 1 second), broadband, and consist 
of high peak sound pressure with rapid rise time and rapid decay (ANSI 
1986; NIOSH 1998; ANSI 2005; NMFS 2018a). Non-impulsive sounds (e.g., 
aircraft, machinery operations such as drilling or dredging, vibratory 
pile driving, and active sonar systems) can be broadband, narrowband or 
tonal, brief or prolonged (continuous or intermittent), and typically 
do not have the high peak sound pressure with raid rise/decay time that 
impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018a). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward 1997 in Southall et al., 2007).
    Three types of hammers would be used on this project: impact, 
vibratory, and DTH. Impact hammers operate by repeatedly dropping a 
heavy piston onto a pile to drive the pile into the substrate.

[[Page 9235]]

Sound generated by impact hammers is characterized by rapid rise times 
and high peak levels, a potentially injurious combination (Hastings and 
Popper, 2005). Vibratory hammers install piles by vibrating them and 
allowing the weight of the hammer to push them into the sediment. 
Vibratory hammers produce significantly less sound than impact hammers. 
Peak sound pressure levels (SPLs) may be 180 dB or greater, but are 
generally 10 to 20 dB lower than SPLs generated during impact pile 
driving of the same-sized pile (Oestman et al., 2009). Rise time is 
slower, reducing the probability and severity of injury, and sound 
energy is distributed over a greater amount of time (Nedwell and 
Edwards 2002; Carlson et al., 2005).
    A DTH hammer is essentially a drill bit that drills through the 
bedrock using a rotating function like a normal drill, in concert with 
a hammering mechanism operated by a pneumatic (or sometimes hydraulic) 
component integrated into the DTH hammer to increase speed of progress 
through the substrate (i.e., it is similar to a ``hammer drill'' hand 
tool). The sounds produced by the DTH method contain both a continuous 
non-impulsive component from the drilling action and an impulsive 
component from the hammering effect. Therefore, we treat DTH systems as 
both impulsive and non-impulsive sound source types simultaneously.
    The likely or possible impacts of TMC's proposed activity on marine 
mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of equipment and personnel; however, any impacts to marine 
mammals are expected to be primarily acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during pile 
driving and drilling.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving or drilling is the primary means by which 
marine mammals may be harassed from the TMC's specified activity. In 
general, animals exposed to natural or anthropogenic sound may 
experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al., 2007). In general, exposure to 
pile driving or drilling noise has the potential to result in auditory 
threshold shifts and behavioral reactions (e.g., avoidance, temporary 
cessation of foraging and vocalizing, changes in dive behavior). 
Exposure to anthropogenic noise can also lead to non-observable 
physiological responses such an increase in stress hormones. Additional 
noise in a marine mammal's habitat can mask acoustic cues used by 
marine mammals to carry out daily functions such as communication and 
predator and prey detection. The effects of pile driving or drilling 
noise on marine mammals are dependent on several factors, including, 
but not limited to, sound type (e.g., impulsive vs. non-impulsive), the 
species, age and sex class (e.g., adult male vs. mom with calf), 
duration of exposure, the distance between the pile and the animal, 
received levels, behavior at time of exposure, and previous history 
with exposure (Wartzok et al., 2004; Southall et al., 2007). Here we 
discuss physical auditory effects (threshold shifts) followed by 
behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in decibels (dB). A TS can be 
permanent or temporary. As described in NMFS (2018), there are numerous 
factors to consider when examining the consequence of TS, including, 
but not limited to, the signal temporal pattern (e.g., impulsive or 
non-impulsive), likelihood an individual would be exposed for a long 
enough duration or to a high enough level to induce a TS, the magnitude 
of the TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how an animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al., 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960; 
Kryter et al., 1966; Miller 1974; Ahroon et al., 1996; Henderson et 
al., 2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al., 2008), there are no empirical data measuring PTS 
in marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--TTS is a temporary, reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range above a previously established 
reference level (NMFS 2018). Based on data from cetacean TTS 
measurements (see Southall et al., 2007), a TTS of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability 
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in 
Finneran (2015), marine mammal studies have shown the amount of TTS 
increases with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, the amount of 
TTS is typically small and the growth curves have shallow slopes. At 
exposures with higher SELcum, the growth curves become steeper and 
approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during a time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Many studies have examined noise-induced hearing loss in marine 
mammals (see Finneran (2015) and Southall et al. (2019) for summaries). 
For cetaceans, published data on the onset of TTS are limited to the 
captive bottlenose dolphin (Tursiops truncatus),

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beluga whale (Delphinapterus leucas), harbor porpoise, and Yangtze 
finless porpoise (Neophocoena asiaeorientalis), and for pinnipeds in 
water, measurements of TTS are limited to harbor seals, elephant seals 
(Mirounga angustirostris), and California sea lions (Zalophus 
californianus). These studies examine hearing thresholds measured in 
marine mammals before and after exposure to intense sounds. The 
difference between the pre-exposure and post-exposure thresholds can be 
used to determine the amount of threshold shift at various post-
exposure times. The amount and onset of TTS depends on the exposure 
frequency. Sounds at low frequencies, well below the region of best 
sensitivity, are less hazardous than those at higher frequencies, near 
the region of best sensitivity (Finneran and Schlundt, 2013). At low 
frequencies, onset-TTS exposure levels are higher compared to those in 
the region of best sensitivity (i.e., a low frequency noise would need 
to be louder to cause TTS onset when TTS exposure level is higher), as 
shown for harbor porpoises and harbor seals (Kastelein et al., 2019a, 
2019b). In addition, TTS can accumulate across multiple exposures, but 
the resulting TTS will be less than the TTS from a single, continuous 
exposure with the same SEL (Finneran et al., 2010; Kastelein et al., 
2014; Kastelein et al., 2015a; Mooney et al., 2009). This means that 
TTS predictions based on the total, cumulative SEL will overestimate 
the amount of TTS from intermittent exposures such as sonars and 
impulsive sources. Nachtigall et al., (2018) describe the measurements 
of hearing sensitivity of multiple odontocete species (bottlenose 
dolphin, harbor porpoise, beluga, and false killer whale (Pseudorca 
crassidens)) when a relatively loud sound was preceded by a warning 
sound. These captive animals were shown to reduce hearing sensitivity 
when warned of an impending intense sound. Based on these experimental 
observations of captive animals, the authors suggest that wild animals 
may dampen their hearing during prolonged exposures or if conditioned 
to anticipate intense sounds. Another study showed that echolocating 
animals (including odontocetes) might have anatomical specializations 
that might allow for conditioned hearing reduction and filtering of 
low-frequency ambient noise, including increased stiffness and control 
of middle ear structures and placement of inner ear structures (Ketten 
et al., 2021). Data available on noise-induced hearing loss for 
mysticetes are currently lacking (NMFS, 2018).
    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
Available studies show wide variation in response to underwater sound; 
therefore, it is difficult to predict specifically how any given sound 
in a particular instance might affect marine mammals perceiving the 
signal. If a marine mammal does react briefly to an underwater sound by 
changing its behavior or moving a small distance, the impacts of the 
change are unlikely to be significant to the individual, let alone the 
stock or population. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on individuals and populations could be significant 
(e.g., Lusseau and Bejder 2007; Weilgart 2007).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are 
highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007; Weilgart 2007). Behavioral reactions can vary not only among 
individuals but also within an individual, depending on previous 
experience with a sound source, context, and numerous other factors 
(Ellison et al., 2012), and can vary depending on characteristics 
associated with the sound source (e.g., whether it is moving or 
stationary, number of sources, distance from the source). In general, 
pinnipeds seem more tolerant of, or at least habituate more quickly to, 
potentially disturbing underwater sound than do cetaceans, and 
generally seem to be less responsive to exposure to industrial sound 
than most cetaceans. Please see Appendices B-C of Southall et al., 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg 
2000). In many cases, an animal's first and sometimes most economical 
(in terms of energetic costs) response is behavioral avoidance of the 
potential stressor. Autonomic nervous system responses to stress 
typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious

[[Page 9237]]

fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Lankford et al., 2005). Stress responses due to exposure to 
anthropogenic sounds or other stressors and their effects on marine 
mammals have also been reviewed (Fair and Becker 2000; Romano et al., 
2002b) and, more rarely, studied in wild populations (e.g., Romano et 
al., 2002a). For example, Rolland et al., (2012) found that noise 
reduction from reduced ship traffic in the Bay of Fundy was associated 
with decreased stress in North Atlantic right whales. These and other 
studies lead to a reasonable expectation that some marine mammals will 
experience physiological stress responses upon exposure to acoustic 
stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003), however 
distress is an unlikely result of this project based on observations of 
marine mammals during previous, similar projects in the area.
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al., 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked.
    Airborne Acoustic Effects--Although pinnipeds are known to haul-out 
regularly on man-made objects, we believe that incidents of take 
resulting solely from airborne sound are unlikely due to the sheltered 
proximity between the proposed project area and these haulout sites 
(outside of Passage Canal). There is a possibility that an animal could 
surface in-water, but with head out, within the area in which airborne 
sound exceeds relevant thresholds and thereby be exposed to levels of 
airborne sound that we associate with harassment, but any such 
occurrence would likely be accounted for in our estimation of 
incidental take from underwater sound. Therefore, authorization of 
incidental take resulting from airborne sound for pinnipeds is not 
warranted, and airborne sound is not discussed further here. Cetaceans 
are not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.

Marine Mammal Habitat Effects

    The TMC's construction activities could have localized, temporary 
impacts on marine mammal habitat and their prey by increasing in-water 
sound pressure levels and slightly decreasing water quality. However, 
since the proposed location is not heavily used by marine mammals and 
is in close proximity to an area currently used by large passenger and 
shipping vessels, and two active harbors. Construction activities are 
of short duration and would likely have temporary impacts on marine 
mammal habitat through increases in underwater and airborne sound. 
Increased noise levels may affect acoustic habitat (see masking 
discussion above) and adversely affect marine mammal prey in the 
vicinity of the project area (see discussion below). During DTH, 
impact, and vibratory pile driving, elevated levels of underwater noise 
would ensonify the project area where both fish and mammals occur and 
could affect foraging success. Additionally, marine mammals may avoid 
the area during construction, however, displacement due to noise is 
expected to be temporary and is not expected to result in long-term 
effects to the individuals or populations.
    Temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles are 
installed or removed. In general, turbidity associated with pile 
installation is localized to about a 25-ft (7.6 m) radius around the 
pile (Everitt et al., 1980). The sediments of the project site will 
settle out rapidly when disturbed. Cetaceans are not expected to be 
close enough to the pile driving areas to experience effects of 
turbidity, and any pinnipeds could avoid localized areas of turbidity. 
Local strong currents are anticipated to disburse any additional 
suspended sediments produced by project activities at moderate to rapid 
rates depending on tidal stage. Therefore, we expect the impact from 
increased turbidity levels to be discountable to marine mammals and do 
not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals except for the actual 
footprint of the floating dock for the cruise ship dock. The total 
seafloor area likely impacted by the project is relatively small 
compared to the available habitat in Southcentral Alaska and does not 
include any Biologically Important Areas or other habitat of known 
importance. The area is highly influenced by anthropogenic activities. 
Additionally, the total seafloor area affected by pile installation and 
removal is a small area compared to the vast foraging area available to 
marine mammals in the area. At best, the impact area provides marginal 
foraging habitat for marine mammals and fishes. Furthermore, pile 
driving at the project site would not obstruct movements or migration 
of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity.

Effects on Potential Prey

    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species

[[Page 9238]]

(e.g., crustaceans, cephalopods, fish, zooplankton, etc.). Marine 
mammal prey varies by species, season, and location. Here, we describe 
studies regarding the effects of noise on known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay, 
2009). Depending on their hearing anatomy and peripheral sensory 
structures, which vary among species, fishes hear sounds using pressure 
and particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 
2009). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 
1992; Santulli et al., 1999; Paxton et al., 2017). However, some 
studies have shown no or slight reaction to impulse sounds (e.g., 
Wardle et al., 2001; Jorgenson and Gyselman, 2009).
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al., (2012a) showed that a TTS of 4-6 dB was recoverable within 24 
hours for one species. Impacts would be most severe when the individual 
fish is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013), and can be 
mitigated by the use of a bubble curtain (Caltrans 2020).
    The most likely impact to fish from pile driving activities at the 
project areas would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of an area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish in the project area. 
Forage fish form a significant prey base for many marine mammal species 
that occur in the project area. Increased turbidity is expected to 
occur in the immediate vicinity (on the order of 10 ft (3 m) or less) 
of construction activities. However, suspended sediments and 
particulates are expected to dissipate quickly within a single tidal 
cycle. Given the limited area affected and high tidal dilution rates, 
any effects on forage fish are expected to be minor or negligible. 
Finally, exposure to turbid waters from construction activities is not 
expected to be different from the current exposure; fish and marine 
mammals in the Passage Canal are routinely exposed to substantial 
levels of suspended sediment from natural and anthropogenic sources.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed action 
are not likely to have a permanent adverse effect on any fish habitat, 
or populations of fish species. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity. Thus, we 
conclude that impacts of the specified activity are not likely to have 
more than short-term adverse effects on any prey habitat or populations 
of prey species. Further, any impacts to marine mammal habitat are not 
expected to result in significant or long-term consequences for 
individual marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through 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 would 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 context of 
larger 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 proposed 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 proposed to be authorized for this activity. Below we 
describe how the proposed take numbers are estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to

[[Page 9239]]

provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the proposed take estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment). Thresholds have also been developed identifying the 
received level of in-air sound above which exposed pinnipeds would 
likely be behaviorally harassed.
    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, DTH drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., impact pile driving and DTH hammering) or 
intermittent (e.g., scientific sonar) sources.
    TMC's proposed 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 
proposed 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 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected 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 5). Additionally, a bubble curtain would be deployed at a depth 
of 60 feet and would be used during all activities that fall within the 
60-ft. isobath. Therefore, a 5dB reduction is applies to the estimated 
sound source levels for driving these piles only.

[[Page 9240]]



                        Table 5--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 Removal    161 RMS **.............  .......................  U.S. Navy 2015.
 (temporary).
36-in steel pile, DTH Installation     174 RMS................  164 SEL................  Denes et al., 2019;
 (temporary).                                                                             Guan 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 Installation  187 RMS **.............  179 SEL **.............  U.S. Navy 2015.
 (permanent).
36-in steel pile, DTH Installation     169 RMS **.............  159 SEL **.............  Denes et al., 2019;
 (permanent) *.                                                                           Guan 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 Removal    166 RMS................  .......................  U.S. Navy 2015.
 (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 Installation  198.6 RMS..............  186.7 SEL..............  Austin et al. 2016.
48-in steel pile, Impact Installation  198.6 RMS..............  186.7 SEL..............  Austin et al. 2016.
36-in steel pile, DTH Installation     169 RMS **.............  159 SEL **.............  Denes et al., 2019;
 (temporary).                                                                             Guan and Miner, 2020;
                                                                                          Reyff and Heyvaert,
                                                                                          2019; Reyff, 2020;
                                                                                          Heyvaert and Reyff,
                                                                                          2021.
42-in steel pile, DTH Installation *.  174 RMS................  164 SEL................  Denes et al., 2019;
                                                                                          Guan and Miner, 2020;
                                                                                          Reyff and Heyvaert,
                                                                                          2019; Reyff, 2020;
                                                                                          Heyvaert and Reyff,
                                                                                          2021.
48-in steel pile, DTH Installation *.  174 RMS................  171 SEL................  Denes et al., 2019;
                                                                                          Guan 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 proposed 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,
  2015; 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) (Table 1 
includes number of piles and duration; Table 5 includes sound pressure 
and sound exposure levels for each pile type).

Level B Harassment Zones

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

TL = B * log10 (R1/R2),

Where:

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

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for TMC's proposed activities. The Level B harassment zones 
and areas of zones of influence (ZOIs) for the proposed activities are 
shown in Table 6.

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

[[Page 9241]]

piles per day, duration and/or strikes per pile) are presented in Table 
1. The maximum RMS SPL, SEL, and resulting isopleths are reported in 
Table 5 and 6.

                  Table 6--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               5.2           0.5           7.7          3.2          0.2        5,412
 Installation (temporary).......
36-in steel pile, Vibratory               5.2           0.5           7.7          3.2          0.2        5,412
 Removal (temporary)............
36-in steel pile, DTH                   681.1          24.5         820.9        368.8         26.9        6,310
 Installation (temporary).......
36-in steel pile, Vibratory               6.8           0.6          10.1          4.2          0.3        5,412
 Installation (permanent).......
36-in steel pile, Impact              2,015.1          71.7       2,400.3      1,078.4         78.5          631
 Installation (permanent).......
36-in steel pile, DTH                   799.7          28.4         952.6          428         31.2        6,310
 Installation (permanent) *.....
----------------------------------------------------------------------------------------------------------------
                                  No Bubble Curtain (depths greater than 60 ft)
----------------------------------------------------------------------------------------------------------------
36-in steel pile, Vibratory              11.2             1          16.6          6.8          .05       11,659
 Installation (temporary).......
36-in steel pile, Vibratory              11.2             1          16.6          6.8          .05       11,659
 Removal (temporary)............
42-in steel pile, Vibratory              20.6           1.8          30.5         12.5          0.9       16,343
 Installation...................
48-in steel pile, Vibratory                13           1.2          19.2          7.9          0.6       16,343
 Installation...................
42-in steel pile, Impact              6,570.9         233.7         7,827      3,516.4          256        3,744
 Installation...................
48-in steel pile, Impact              5,014.6         178.4       5,973.1      2,683.6        195.4        3,744
 Installation...................
36-in steel pile, DTH                 1,484.7          52.8       1,768.5        794.6         57.9     * 39,811
 Installation (temporary).......
42-in steel pile, DTH                 1,722.9          61.3       2,052.2          922         67.1     * 39,811
 Installation *.................
48-in steel pile, DTH                 5,045.7         179.5       6,010.2      2,700.2        196.6     * 39,811
 Installation *.................
----------------------------------------------------------------------------------------------------------------
* Differs from TMC's application due to difference in source level use. See Table 5.

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 Passage Canal includes local knowledge, 
previous marine construction projects in the Whittier area, and 
available scientific literature. A summary of proposed 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 would 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 Passage Canal, and infrequent species would have three group 
sightings per week in Passage Canal, or slightly fewer than one group 
sighting every two days (Table 7). In these estimations, a sighting 
does not equal one animal; a sighting equals one group of each 
particular species. To standardize observation estimates across 
species, these numbers were distilled 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 would be occurring, 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. For more detailed breakdown of each species occurrence 
information, see Table 7 in TMC's application.

                        Table 7--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 proposed for authorization.
    Using the hourly occurrence probability for a species, this was 
multiplied by the estimated group size and by the number of hours of 
each type of pile driving activity for total take estimate.


[[Page 9242]]


Estimated take = Hourly occurrence estimate x average group size x 
hours of pile driving activity

    For species infrequently seen in the Passage Canal (humpback whale, 
Dall's porpoise, and killer whale) and rarely seen close to the project 
location, only hours of pile driving with the largest resulting 
isopleths (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, and therefore construction would be shut 
down before they approach the Level B harassment zone.
    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 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 8--Proposed Authorized Amount of Taking and Percent of Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           Average group   Take by Level   Take by Level                    Percent of
                  Species                               Stock                  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                                0              29              29             4.9
                                             Sea Transient.
Harbor Seal...............................  Prince William Sound........             3.5              40             170             210              <1
Steller Sea Lion..........................  Western US..................               4               0             218             218              <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
* AT1 transient stock take calculation resulted in 0 takes, therefor no takes were requested or are proposed for authorization.

Proposed Mitigation

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

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

[[Page 9243]]

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 9 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 9, 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 9) or 15 minutes have passed 
without re-detection of the animal (30 minutes for large cetaceans);
     As proposed 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 would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). 
Shutdown zones would be based upon the Level A harassment zone for each 
pile size/type and driving method where applicable, as shown in Table 
9.
    A minimum shutdown zone of 35 m would be applied for all in-water 
construction activities if the Level A harassment zone is less than 35 
m (i.e., vibratory pile driving). A 10 m shutdown zone would also serve 
to protect marine mammals from collisions with project vessels during 
pile driving and other construction activities, such as barge 
positioning or drilling. 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 9 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.
    TMC would 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-IHA 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 would 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 9--Proposed Shutdown Zones and Monitoring Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Minimum shutdown zone
                                                                   -------------------------------------------------------------------------  Harassment
                             Activity                                Low-Frequency    Mid-Frequency    High-Frequency                            zone
                                                                     (LF) Cetaceans   (MF) Cetaceans   (HF) Cetaceans    Phocid    Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barge movements, pile positioning, etc.\1\........................               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        6,310
36-in steel pile, Vibratory Installation (permanent)..............               10               10               10         10         10        5,415

[[Page 9244]]

 
36-in steel pile, Impact Installation (permanent).................            2,055               80            2,400      1,100         80          635
36-in steel pile, DTH Installation(permanent).....................              800               35            1,000        430         35        6,310
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      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              260            7,830    * 1,360        260        3,745
48-in steel pile, Impact Installation.............................            5,015              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 would 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 39,811 m extends longer than Passage Canal, so land masses would block sound
  transmission and distances would be truncated. It would also be impractical to monitor this whole zone outside of Passage Canal. Instead, DTH
  monitoring zone would be the entirety of the Passage Canal and equivalent to the largest Level B harassment zone.

Protected Species Observers

    The placement of PSOs during all construction activities (described 
in the Proposed Monitoring and Reporting section) would ensure that the 
entire shutdown zone is visible. Should environmental conditions 
deteriorate such that the entire shutdown zone would not be visible 
(e.g., fog, heavy rain), pile driving would be delayed until the PSO is 
confident marine mammals within the shutdown zone could be detected.
    PSOs would monitor the full shutdown zones and 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 
would observe the shutdown and monitoring zones for a period of 30 
minutes. The shutdown zone would be considered cleared when a marine 
mammal has not been observed within the zone for that 30-minute period. 
If a marine mammal is observed within the shutdown zones listed in 
Table 10, pile driving activity would be delayed or halted. If work 
ceases for more than 30 minutes, the pre-activity monitoring of the 
shutdown zones would commence. A determination that the shutdown zone 
is clear must be made during a period of good visibility (i.e., the 
entire shutdown zone and surrounding waters must be visible to the 
naked eye).

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 would be required to provide an 
initial set of three strikes from the hammer at reduced energy, 
followed by a 30-second waiting period, then two subsequent reduced-
energy strike sets. Soft-start would be implemented at the start of 
each day's impact pile driving and at any time following cessation of 
impact pile driving for a period of 30 minutes or longer.

Bubble Curtain

    A bubble curtain 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 proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed 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.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);

[[Page 9245]]

     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 action; 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 would 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 would be used;
     At least one PSO would have prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator would be designated. The lead 
observer would be required to have prior experience working as a marine 
mammal observer during construction.
    PSOs must 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 would 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 Gradual Point, and back southwest toward Trinity 
Point and Emerald Island as shown in Figure 8 of the Marine Mammal 
Monitoring Plan. All PSOs would 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 would be conducted 30 minutes before, during, and 30 
minutes after all in water construction activities. In addition, PSOs 
would record all incidents of marine mammal occurrence, regardless of 
distance from activity, and would document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes.
    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 would 
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

[[Page 9246]]

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;
    [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 (e.g., hammer model, energy), and total 
pile driving duration;
     Whether a sound attenuation device is used and, if so, a 
detailed description of the device and the duration of its use per 
pile;
     DTH: 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), 
cumulative sound exposure level (SELcum), peak sound 
pressure level (SPLpeak), and single strike exposure sound 
level (SELs-s);
     One-third octave band spectrum and power spectral density 
plot.
     Evaluation of acoustic sound record levels for pile 
driving activities (DTH).
     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;
     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 2 for which take could occur, given that NMFS expects the 
anticipated effects of the proposed 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. Potential 
takes could occur if individuals are present in the ensonified zone 
when these activities are underway.
    No serious injury or mortality would be 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

[[Page 9247]]

through the construction method and the implementation of the planned 
mitigation measures (see Proposed Mitigation section).
    Take by Level A harassment is proposed 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 proposed 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 proposed for authorization by Level A 
harassment is very low for both marine mammal stocks and species. If 
hearing impairment occurs, it is most likely that the affected animal 
would lose only a few decibels in its hearing sensitivity. Due to the 
small degree anticipated, any PTS potential incurred would not be 
expected to affect the reproductive success or survival of any 
individuals, much less result in adverse impacts on the species or 
stock.
    Additionally, some subset of the individuals that are behaviorally 
harassed could also simultaneously incur some small degree of TTS for a 
short duration of time. However, since the hearing sensitivity of 
individuals that incur TTS is expected to recover completely within 
minutes to hours, it is unlikely that the brief hearing impairment 
would affect the individual's long-term ability to forage and 
communicate with conspecifics, and would therefore not likely impact 
reproduction or survival of any individual marine mammal, let alone 
adversely affect rates of recruitment or survival of the species or 
stock.
    The Level A harassment zones identified in Table 6 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, each pile and break between pile 
installations (to reset equipment and move piles into place), an animal 
would 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 would 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 would 
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 proposed to be 
authorized is extremely small when compared to stock abundance.
    Behavioral responses of marine mammals to pile driving, pile 
removals, 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 would occur for only a portion of the project's duration, any 
harassment occurring would be temporary. Additionally, many of the 
species present in region would only be present temporarily based on 
seasonal patterns or during transit between other habitats. These 
temporary present species would be exposed to even smaller 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 would 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 would have any effect on each stock's ability 
to recover. In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activities 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 preliminary 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 would 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 would be primarily 
in the form of behavioral disturbance, resulting in avoidance of the 
project areas around where impact or vibratory pile driving is 
occurring, with some low-level TTS that may limit the detection of 
acoustic cues for relatively brief amounts of time in relatively 
confined footprints of 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 would not 
adversely affect ESA-designated critical habitat for any species or any 
areas of known biological importance;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and
     TMC would 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 proposed monitoring and 
mitigation

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measures, NMFS preliminarily finds that the total marine mammal take 
from the proposed activity will have a negligible impact on all 
affected marine mammal species or stocks.

Small Numbers

    As noted previously, only small numbers of incidental take 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 proposes 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 would count them as separate takes if they cannot be individually 
identified.
    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 proposed for 
authorization is believed to be an even smaller portion of the overall 
stock abundance.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals 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 7 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. Harvest of harbor 
seals and Steller sea lions was reported in Tatitlek in 2014, the 
latest year for which data is available from ADF&G's Community 
Subsistence Information System (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 proposed project is not likely to adversely impact the 
availability of any marine mammal species or stocks that are commonly 
used for subsistence purposes or to impact subsistence harvest of 
marine mammals in the region because:
     there is no recent recorded subsistence harvest of marine 
mammals in the area;
     construction activities are localized and temporary;
     mitigation measures will be implemented to minimize 
disturbance of marine mammals in the action area; and,
     the project will not result in significant changes to 
availability of subsistence resources.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the proposed mitigation and 
monitoring measures, NMFS has preliminarily determined that there will 
not be an unmitigable adverse impact on subsistence uses from TMC's 
proposed activities.

Endangered Species Act

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

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue 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. A 
draft of the proposed IHA can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#active-authorizations.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this notice of proposed IHA for the proposed 
construction. We also request comment on the potential renewal of this 
proposed IHA as described in the paragraph below. Please include with 
your comments any supporting data or literature citations to help 
inform decisions on the request for this IHA or a subsequent renewal 
IHA.
    On a case-by-case basis, NMFS may issue a one-time, 1 year renewal 
IHA following notice to the public providing an additional 15 days for 
public comments when (1) up to another year of identical or nearly 
identical activities as described in the Description of

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Proposed Activities section of this notice is planned or (2) the 
activities as described in the Description of Proposed Activities 
section of this notice would not be completed by the time the IHA 
expires and a renewal would allow for completion of the activities 
beyond that described in the Dates and Duration section of this notice, 
provided all of the following conditions are met:
     A request for renewal is received no later than 60 days 
prior to the needed renewal IHA effective date (recognizing that the 
renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA).
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    Upon review of the request for renewal, the status of the affected 
species or stocks, and any other pertinent information, NMFS determines 
that there are no more than minor changes in the activities, the 
mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: February 8, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-02997 Filed 2-10-23; 8:45 am]
BILLING CODE 3510-22-P