Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Lutak Dock Replacement Project, Haines Borough, Alaska, 78310-78330 [2023-25097]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 219 (Wednesday, November 15, 2023)]
[Notices]
[Pages 78310-78330]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-25097]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD361]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Lutak Dock Replacement Project, 
Haines Borough, 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 Haines Borough for 
authorization to take marine mammals incidental to the Lutak dock 
replacement project in Lutak, 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

[[Page 78311]]

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 December 
15, 2023.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, NMFS 
and should be submitted via email to [email protected]. Electronic 
copies of the application and supporting documents, as well as a list 
of the references cited in this document, may be obtained online at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of 
problems accessing these documents, please call the contact listed 
above.
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments, including all attachments, must 
not exceed a 25-megabyte file size. All comments received are a part of 
the public record and will generally be posted online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities 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: Craig Cockrell, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

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

National Environmental Policy Act

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

Summary of Request

    On July 10, 2023, NMFS received a request from the Haines Borough 
for an IHA to take marine mammals incidental to pile driving involving 
impact, vibratory, and down-the-hole (DTH) drilling to replace the 
Lutak Dock. Following NMFS' review of the application, Haines Borough 
submitted a revised version on October 11, 2023. The application was 
deemed adequate and complete October 16, 2023. Haines Borough's request 
is for take of six species of marine mammals by Level B harassment and, 
for a subset of three of these species, Level A harassment. Neither 
Haines Borough nor NMFS expect serious injury or mortality to result 
from this activity and, therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    The purpose of the project is to replace the dock facility, 
constructed in 1953, that has reached the end of its 60-year service 
life and has experienced local structural failures. The Lutak Dock is 
an important maritime shipping link that is connected by road to the 
mainland of Alaska and Canada and is an important connection for the 
Alaska Marine Highway System to many other Alaskan ports. Takes of 
marine mammals by Level A and Level B harassment are expected to occur 
due to impact, DTH, and vibratory pile driving and removal. The project 
would occur in Lutak inlet which is located in Haines Borough in 
southeast Alaska. It is expected to take up to 234 non-consecutive days 
to complete the pile driving and removal activities.

Dates and Duration

    Construction activities are expected to over a 1-year year period 
from winter 2023 to winter of 2024. It is expected to take up to 234 
non-consecutive days of in water work over a 1-year work window to 
complete the pile driving activities. Pile driving would be completed 
intermittently throughout daylight hours. All pile driving is expected 
to be completed during one phase of construction.

Specific Geographic Region

    The project area is in the Haines Borough on the southern shore of 
Lutak Inlet, at the upper reaches of Lynn Canal in southeast Alaska. 
Lutak Dock is located approximately 6 kilometers (km) (4 miles (mi)) 
northwest of downtown Haines. Lutak Inlet is approximately 9 km (6 mi)-
long and measures less than 2 km (1 mi) across from shore to shore at 
its widest point and is about 110 meters (m) (360 feet (ft)) deep at 
its entrance between Tanani Point and Taiya Point. Depths at the 
proposed action area are shallower, approximately 8 m (25 ft) to 30 m 
(100 ft). To the north of the proposed action area, the Ferebee River 
empties into the Taiyasanka Harbor and then into Lutak Inlet; to the 
west of the proposed action area, Chilkoot Lake empties into Lutak 
Inlet

[[Page 78312]]

via the Chilkoot River (see Figure 7 in Haines Borough's application).
[GRAPHIC] [TIFF OMITTED] TN15NO23.037

    Figure 1. Project location of the Lutak Dock Replacement project

Detailed Description of the Specified Activity

    The Haines Borough proposes to encapsulate the existing Lutak Dock 
structure with a new dock structure of similar design. In-water 
construction activities associated with the project would include 
impact pile driving, vibratory pile driving and removal, and DTH 
installation. Pile removal may also be completed using a ``dead pull'' 
method, where a pile is tethered to a crane and is removed directly. 
Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. Vibratory hammers install 
piles by vibrating them and allowing the weight of the hammer to push 
them into the sediment. 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.
    Pile removal would consist of 24 16 inches (in) steel pipe piles 
(41 centimeters (cm)) that make up the 4 mooring dolphins and 1 24-in 
(61-cm) steel guide pile. These piles would all be removed using dead 
pull or vibratory removal methods. Dead pull methods would not have 
impacts on marine mammals; however, we assume that all pile removal is 
conducted using vibratory hammer. A template frame would then be welded 
to 42 36-in (91-cm) temporary piles that is capable of holding 10 
permanent piles in each section. The temporary piles would be set in 
place using vibratory and impact hammers (as needed). The template 
frame would be used to position the 180 42-in (107-cm) permanent piles 
across the length of the dock. Up to 10 permanent piles would be set at 
a time, before moving the template to the next position to install the 
next 10 piles. Permanent piles would be set with vibratory hammers and 
if required, impact hammers would be used to drive the pile past any 
overburden to the bedrock. Once the pile reaches bedrock DTH systems 
would socket the pile approximately 10-ft into the bedrock. A permanent 
55.5-in (140-cm) sheet pile would be installed using vibratory and 
impact hammers and attached to the permanent piles to make up the new 
dock return wall.

[[Page 78313]]



                                             Table 1--Number and Types of Piles To Be Installed and Removed
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                                                                                                                      Permanent pile       Sheet pile
                                            Guide pile        Dolphin pile      Temporary pile     Temporary pile      installation       installation
                                         removal (steel)    removal (steel)        (steel)        removal (steel)        (steel)            (steel)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile Diameter size (in)...............                 24                 16                 36                 36                 42               55.5
Vibratory Pile Driving/Removal:
    Total Quantity....................                  1                 24                 42                 42                180                 40
    Max # of Piles per day............                  1                  4                  4                  4                  4                  6
    Vibratory time per pile (min).....                 45                 45                 15                 15                 45                 30
    Number of Days....................                  1                  6                 11                 11                 45                  7
Impact Pile Driving:
    Total Quantity....................                N/A                N/A                 42                N/A                180                 40
    Piles per day.....................                N/A                N/A                  4                N/A                  4                  6
    Strikes per pile..................                N/A                N/A                900                N/A              1,500                900
    Number of Days....................                N/A                N/A                 11                N/A                 45                  7
Down the Hole Drilling:
    Total Quantity....................                N/A                N/A                N/A                N/A                180                N/A
    Piles per day.....................                N/A                N/A                N/A                N/A                  2                N/A
    Duration time per pile (min)......                N/A                N/A                N/A                N/A                300                N/A
    Strikes per pile..................                N/A                N/A                N/A                N/A            324,000                N/A
    Number of Days....................                N/A                N/A                N/A                N/A                 90                N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Above-water construction would include replacement of the dock 
surface and fill material placement. This above-water work is not 
expected to result in any take of marine mammals, as there are no 
pinniped haulouts close enough to be affected by airborne noise.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (see Proposed Mitigation and 
Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR), where known. PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS' 
SARs). While no serious injury or mortality is anticipated or proposed 
to be authorized here, PBR and annual serious injury and mortality from 
anthropogenic sources are included here as gross indicators of the 
status of the species or stocks and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' Alaska SARs (Young et. al., 2023). All values presented in table 
2 are the most recent available at the time of publication and are 
available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

[[Page 78314]]



                                            Table 2--Species Likely Impacted by the Specified Activities \1\
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                                                                                         ESA/ MMPA status;   Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
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                                            Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Hawai[revaps]i.........  -,-, N              11,278 (0.56, 7,265,          127      27.09
                                                                                                             2020).
                                                               Mexico-North Pacific...  T, D, Y             N/A (N/A, N/A, 2006)..        UND       0.57
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                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Eastern North Pacific    -, -, N             1,920 (N/A, 1,920,             19        1.3
                                                                Alaska Resident.                             2019).
                                                               Eastern Northern         -, -, N             302 (N/A, 302, 2018)..        2.2        0.2
                                                                Pacific Northern
                                                                Resident.
                                                               West Coast Transient...  -, -, N             349 (N/A, 349, 2018)..        3.5        0.4
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Northern Southeast       -, -, N             1,619 (0.26, 1,250,            13        5.6
                                                                Alaska Inland Waters.                        2019).
    Dall's Porpoise.................  Phocoenoides dalli.....  Alaska.................  -, -, N             UND (UND, UND, 2015)..        UND         37
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Eastern DPS............  -, -, N             43,201 (N/A, 43,201,        2,592        112
                                                                                                             2017).
                                                               Western DPS............  E, D, Y             52,932 (N/A, 52,932,          318        254
                                                                                                             2019).
Family Phocidae (earless seals)
    Harbor Seal.....................  Phoca vitulina.........  Lynn Canal/Stephens      -, -, N             13,388 (N/A, 11,867,          214         50
                                                                Passage.                                     2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: https://www. 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. In some cases, CV is not applicable.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
  CV associated with estimated mortality due to commercial fisheries is presented in some cases.

    As indicated above, all six species (with 10 managed stocks) in 
table 2 temporally and/or spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. While minke whales 
(Balaenoptera acutorostrata) and Pacific white-sided dolphins 
(Lagenorhynchus obliquidens) have been sighted in the area, the 
temporal and spatial occurrence of these species is such that take is 
not expected to occur, and they are not discussed further beyond the 
explanation provided here. A construction project to improve the Alaska 
Marine Lines, Inc. dock in Lutak, AK authorized the take of two minke 
whales by Level B harassment (85 FR 22139, April 21, 2020). A similar 
project in Skagway, AK to install dolphins on the Railroad Dock also 
authorized the take of two minke whales by Level B harassment (84 FR 
4777, February 19, 2019). Pacific white-sided dolphins were not 
authorized for take in either project due to their extremely rare 
occurrence in the project areas (Dahlheim et al., 2009). There were no 
sightings by monitors of minke whales or Pacific white-sided dolphins 
during either construction project (Tom Mortensen Associates, LLC, 
2021; Owl Ridge Natural Resource Consultants, 2019). Therefore, take is 
not expected for these species and they are not discussed further in 
this document.

Humpback Whale

    On September 8, 2016, NMFS divided the once single species into 14 
distinct population segments (DPS) under the ESA, removed the species-
level listing as endangered, and, in its place, listed four DPSs as 
endangered and one DPS as threatened (81 FR 62259; September 8, 2016). 
The remaining nine DPSs were not listed. There are four DPSs in the 
North Pacific, including Western North Pacific and Central America, 
which are listed as endangered, Mexico, which is listed as threatened, 
and Hawaii, which is not listed.
    The 2022 Alaska and Pacific SARs described a revised stock 
structure for humpback whales which modifies the previous stocks 
designated under the MMPA to align more closely with the ESA-designated 
DPSs (Caretta et al., 2023; Young et al., 2023). Specifically, the 
three previous North Pacific humpback whale stocks (Central and western 
North Pacific stocks and a CA/OR/WA stock) were replaced by five 
stocks, largely corresponding with the ESA-designated DPSs. These 
include Western North Pacific and Hawaii stocks and a Central America/
Southern Mexico-CA/OR/WA stock (which corresponds with the Central 
America DPS). The remaining two stocks, corresponding with the Mexico 
DPS, are the Mainland Mexico-CA/OR/WA and Mexico-North Pacific stocks 
(Caretta et al., 2023; Young et al., 2023). The former stock is 
expected to occur along the west coast from California to southern 
British Columbia, while the latter stock may occur across the Pacific, 
from northern British Columbia through the Gulf of Alaska and Aleutian 
Islands/Bering Sea region to Russia.

[[Page 78315]]

    The Hawai[revaps]i stock consists of one demographically 
independent population (DIP)--Hawai[revaps]i-southeast Alaska/northern 
British Columbia DIP and one unit--Hawai[revaps]i-north Pacific unit, 
which may or may not be composed of multiple DIPs (Wade et al., 2021). 
The DIP and unit are managed as a single stock at this time, due to the 
lack of data available to separately assess them and lack of compelling 
conservation benefit to managing them separately (NMFS, 2023; NMFS, 
2019; NMFS, 2022b). The DIP is delineated based on two strong lines of 
evidence: genetics and movement data (Wade et al., 2021). Whales in the 
Hawai[revaps]i-southeast Alaska/northern British Columbia DIP winter 
off Hawai[revaps]i and largely summer in southeast Alaska and northern 
British Columbia (Wade et al., 2021). The group of whales that migrate 
from Russia, western Alaska (Bering Sea and Aleutian Islands), and 
central Alaska (Gulf of Alaska excluding southeast Alaska) to 
Hawai[revaps]i have been delineated as the Hawai[revaps]i-North Pacific 
unit (Wade et al., 2021). There are a small number of whales that 
migrate between Hawai[revaps]i and southern British Columbia/
Washington, but current data and analyses do not provide a clear 
understanding of which unit these whales belong to (Wade et al., 2021; 
Caretta et al., 2023; Young et al., 2023).
    The Mexico-North Pacific unit is likely composed of multiple DIPs, 
based on movement data (Martien et al., 2021; Wade, 2021, Wade et al., 
2021). However, because currently available data and analyses are not 
sufficient to delineate or assess DIPs within the unit, it was 
designated as a single stock (NMFS, 2023a; NMFS, 2019; NMFS, 2022c). 
Whales in this stock winter off Mexico and the Revillagigedo 
Archipelago and summer primarily in Alaska waters (Martien et al., 
2021; Carretta et al., 2023; Young et al., 2023).
    NMFS identified most of southeast Alaska, including Lynn Canal, as 
a Biologically Important Area (BIA) for humpback whales for feeding 
during the months of June through August; however, the proposed action 
area is northwest of and outside the boundaries of the BIA (Wild et 
al., 2023). No humpback whales were observed in Lutak Inlet during 
monitoring for the Alaska Marine Lines, Inc. dock improvement project 
in Lutak in November 2020 (Tom Mortensen Associates, LLC, 2021). 
However, sightings of humpbacks are common in southeast Alaska 
(Dahlheim et al., 2009). In Lynn Canal and Lutak Inlet, humpback whales 
are traditionally observed during seasons of high prey concentration, 
May through September (Witteveen et al., 2011; SolsticeAK, 2023).
    Group sizes of humpback whales vary depending on the season, but 
based on sightings from local charter captains a group size of two can 
be expected from May through September and from October through April a 
group size of one can be expected (SolsticeAK, 2023; Straley et al., 
2018; Happywhale, 2023).

Killer Whale

    Based on data regarding association patterns, acoustics, movements, 
and genetic differences, eight killer whale stocks are now recognized 
within the Pacific U.S. Exclusive Economic Zone, seven of which occur 
in Alaska. Of these eight stocks the three stocks most likely to occur 
in Lynn Canal are (1) the Alaska Resident stock which ranges from 
southeastern Alaska to the Aleutian Islands and Bering Sea; (2) the 
Northern Resident stock which occurs from Washington State through part 
of southeastern Alaska; and (3) the West Coast Transient stock which 
ranges from California through southeastern Alaska (Muto et al., 2022).
    Transient killer whales hunt and feed primarily on marine mammals, 
while residents forage primarily on fish. Transient killer whales feed 
primarily on harbor seals, Dall's porpoises, harbor porpoises, and sea 
lions. Resident killer whale populations in the eastern North Pacific 
feed mainly on salmonids, showing a strong preference for Chinook 
salmon (NMFS, 2016a).
    Killer whales are common near the project area. During the 
monitoring of the White Pass and Yukon Railroad dock dolphin project 
groups of killer whales from one to nine individuals were observed from 
March through April (Owl Ridge Natural Resource Consultants, 2019). 
Group sizes of up to 15 may be expected during the project based on 
surveys conducted in southeast Alaska conducted by Witteveen et al. 
(2011).

Harbor Porpoise

    The 2022 Alaska SARs described a revised stock structure for 
southeast Alaska harbor porpoise, which were split from one stock into 
three: the Northern Southeast Alaska Inland Waters, Southern Southeast 
Alaska Inland Waters, and Yakutat/Southeast Alaska Offshore Waters 
harbor porpoise stocks. This update better aligns harbor porpoise stock 
structure with genetics, trends in abundance, and information regarding 
discontinuous distribution trends (Young et al., 2023). Harbor 
porpoises found in Lutak are assumed to be members of the northern 
southeast Alaska Inland Waters stock, which encompasses Cross Sound, 
Glacier Bay, Icy Strait, Chatham Strait, Frederick Sound, Stephens 
Passage, Lynn Canal, and adjacent inlets.
    Harbor porpoise are expected to be infrequent visitors to the upper 
portions of the Lynn Canal (Dahlheim et al., 2009). Recent monitoring 
from the Alaska Marine Lines, Inc. dock improvement project in Lutak 
and the White Pass and Yukon Railroad dock dolphin project did not 
observe any harbor porpoises in the project areas during construction 
(Tom Mortensen Associates, LLC, 2021; Owl Ridge Natural Resource 
Consultants, 2019). A group size of two harbor porpoise is expected 
during the project based on survey data from Dahlheim et al. (2009).

Dall's Porpoise

    Dall's porpoises are found throughout the North Pacific, from 
southern Japan to southern California and north to the Bering Sea. All 
Dall's porpoises in Alaska are members of the Alaska stock, and those 
off California, Oregon, and Washington are part of a separate stock. 
This species can be found in offshore, inshore, and nearshore habitat, 
but prefers waters more than 600 ft (183 m) deep (Dahlheim et al. 2009; 
Jefferson, 2009).
    Dall's porpoises have been consistently observed in Lynn Canal, 
Stephens Passage, upper Chatham Strait, Frederick Sound, and Clarence 
Strait (Dalheim et al., 2000). The species is generally found in waters 
deeper than Lutak Inlet. However, despite generalized water depth 
preferences, Dall's porpoises may occur in shallower waters. Moran et 
al. (2018a) recently mapped Dall's porpoise distributions in bays, 
shallow water, and nearshore areas of Prince William Sound, habitats 
not typically utilized by this species. No Dall's porpoises were 
observed in Lutak Inlet during monitoring for the Alaska Marine Lines, 
Inc. dock improvement project in Lutak and the White Pass and Yukon 
Railroad dock dolphin project did not observe any Dall's porpoises in 
the project areas during construction (Tom Mortensen Associates, LLC, 
2021; Owl Ridge Natural Resource Consultants, 2019). Although sightings 
near the project area are infrequent, a local tour boat captain 
confirmed there are occasional sightings of Dall's porpoises in Taiya 
Inlet, but most often they are seen farther south near Mud Bay, 15 km 
(9 mi) south of the project area (SolsticeAK 2023). It is expected that 
groups of two Dall's porpoise would be present in the project area 
based on survey data from Dahlheim et al. (2009) and on sighting data 
from above.

[[Page 78316]]

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 DPSs in 1997 (62 
FR 24345, May 5, 1997). The eastern DPS remained classified as 
threatened until it was delisted on November 4, 2013 (78 FR 66140). 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 on May 5, 1997 (62 FR 24345). Both stocks of 
Steller sea lions are found in southeast Alaska and have the potential 
to occur in the project area, however it is more likely they would be 
from the eastern stock.
    The majority of Steller sea lions that inhabit southeast Alaska are 
part of the eastern DPS; however, branded individuals from the western 
DPS make regular movements across the 144[deg] longitude boundary to 
the northern ``mixing zone'' haulouts and rookeries within southeast 
Alaska (Jemison et al., 2013). While haulouts and rookeries in the 
northern portion of southeast Alaska may be important areas for wDPS 
animals, there continues to be little evidence that their regular range 
extends to the southern haulouts and rookeries in southeast Alaska 
(Jemison et al., 2018). However, genetic data analyzed in Hastings et 
al. (2020) indicated that up to 1.4 percent of Steller sea lions near 
Lutak Inlet may be members of the western DPS.
    Gran Point is the closest major haulout and designated critical 
habitat area, approximately 10 miles (16 kilometers) from the Project 
site and outside of Taiya Inlet. The Lutak Inlet eulachon (Thaleichtys 
pacificus) run between April and May correlates with higher sea lion 
numbers near the Project site, with the Taiya Point haulout 
(approximately 10 miles (16.1 kilometers) away) being a popular land 
site (NOAA, 2022b).
    During the White Pass & Yukon Route Railroad dock dolphin project, 
Steller sea lions were sighted on 27 separate days with 165 individuals 
observed. A majority of the sightings occurred during April and May, 
with only six individuals sighted in March. Although a few sightings 
were 500 m from pile driving activities, most sightings were recorded 
over 1,000 m away from the pile driving site. Sightings were of single 
individuals and rafts up to 25 individuals (Owl Ridge Natural Resource 
Consultants, 2019). Monitoring at the Alaska Marine Lines, Inc. dock 
improvement project in Lutak observed lone Steller sea lions on 2 
separate days (November 12 and 15, 2020). The sightings were between 
800 m and 1,400 m from the pile driving (Tom Mortensen Associates, LLC, 
2020). It is expected that groups of 40 may occur from mid-March 
through May during the eulachon run and groups of 2 the rest of the 
year.

Harbor Seal

    Harbor seals inhabit coastal and estuarine waters off 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 (Womble et al., 2009; 
Allen and Angliss, 2015). Harbor seals occurring in the project area 
belong to the Lynn Canal/Stephens Passage (LC/SP) stock. Harbor seals 
are common in Lutak Inlet and in Chilkat Inlet where there is a small 
haulout at Pyramid Island. They are abundant in the Chilkat and 
Chilkoot rivers in late fall and winter during spawning runs of salmon 
(Onchorhynchus spp.) and in the spring (mid-March through mid-May) when 
eulachon are present. As many as about 100 individuals have been 
observed actively feeding in Lutak Inlet near the mouth of the Chilkoot 
River, and at up-river locations during these fish runs (ADF&G, 2016).
    Seven hundred thirty-five harbor seals were observed on 46 days of 
in-water activity, with sightings occurring in all months of the 
project. The majority of the harbor seal observations were near 
Yakutania Point, a harbor seal haulout site. Most of the sightings 
occurred at least 1,000 m from the project site, however harbor seals 
came as close as 150 m and as far as 5,000 m. Harbor seals were 
observed travelling, swimming, playing, milling, looking, hauled out, 
sinking, and feeding (Owl Ridge Natural Resource Consultants, 2019). 
During the Alaska Marine Lines, Inc. dock improvement project in Lutak 
one lone harbor seal was observed 800 m away from the source. It is 
expected that groups of 100 may occur from mid-March through May and 
groups of 5 throughout the rest of the year.

Marine Mammal Hearing

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

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).

[[Page 78317]]

 
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

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

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section provides a discussion of the ways in which components 
of the specified activity may impact marine mammals and their habitat. 
The Estimated Take of Marine Mammals 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 of Marine Mammals section, and the Proposed Mitigation 
section, to draw conclusions regarding the likely impacts of these 
activities on the reproductive success or survivorship of individuals 
and whether those impacts are reasonably expected to, or reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10 to 20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include impact pile driving, vibratory pile driving, vibratory pile 
removal, DTH installation. The sounds produced by these activities fall 
into one of two general sound types: impulsive and non-impulsive. 
Impulsive sounds (e.g., explosions, gunshots, sonic booms, impact pile 
driving) are typically transient, brief (less than 1 second), 
broadband, and consist of high peak sound pressure with rapid rise time 
and rapid decay (ANSI, 1986; NIOSH, 1998; ANSI, 2005; NMFS, 2018). Non-
impulsive sounds (e.g., aircraft, machinery operations such as drilling 
or dredging, vibratory pile driving, and active sonar systems) can be 
broadband, narrowband or tonal, brief or prolonged (continuous or 
intermittent), and typically do not have the high peak sound pressure 
with raid rise/decay time that impulsive sounds do (ANSI, 1995; NIOSH, 
1998; NMFS, 2018). The distinction between these two sound types is 
important because they have differing potential to cause physical 
effects, particularly with regard to hearing (e.g., Ward, 1997; 
Southall, et al. 2007).
    Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. 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).
    DTH systems would also be used during the proposed construction. A 
DTH hammer is essentially a drill bit that drills through the bedrock 
using a rotating function like a normal drill, in concert with a 
hammering mechanism operated by a pneumatic (or sometimes hydraulic) 
component integrated into the DTH hammer to increase speed of progress 
through the substrate (i.e., it is similar to a ``hammer drill'' hand 
tool). The sounds produced by the DTH methods contain both a continuous 
non-impulsive component from the drilling action and an impulsive 
component from the hammering effect. Therefore, NMFS treats DTH systems 
as both impulsive and continuous, non-impulsive sound source types 
simultaneously.
    The likely or possible impacts of the Haines Borough's proposed 
activities on marine mammals could involve both non-acoustic and 
acoustic stressors. Potential non-acoustic stressors could result from 
the physical presence of the equipment and personnel; however, given 
there are no known pinniped haul-out sites in the vicinity of the 
proposed project site, visual and other non-acoustic stressors would be 
limited, and any impacts to marine mammals are

[[Page 78318]]

expected to primarily be acoustic in nature.

Auditory Effects

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving or drilling is the primary means by which 
marine mammals may be harassed from the Haines Borough specified 
activity. In general, animals exposed to natural or anthropogenic sound 
may experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al., 2007; Southall et al., 2019). In 
general, exposure to pile driving or drilling noise has the potential 
to result in auditory threshold shifts and behavioral reactions (e.g., 
avoidance, temporary cessation of foraging and vocalizing, changes in 
dive behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses, such an increase in stress 
hormones. Additional noise in a marine mammal's habitat can mask 
acoustic cues used by marine mammals to carry out daily functions, such 
as communication and predator and prey detection. The effects of pile 
driving or drilling noise on marine mammals are dependent on several 
factors, including, but not limited to, sound type (e.g., impulsive vs. 
non-impulsive), the species, age and sex class (e.g., adult male vs. 
mom with calf), duration of exposure, the distance between the pile and 
the animal, received levels, behavior at time of exposure, and previous 
history with exposure (Wartzok et al., 2004; Southall et al., 2007). 
Here we discuss physical auditory effects (threshold shifts) followed 
by behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018a), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al., 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral). When considering auditory effects for the DOT&PF's proposed 
activities, vibratory pile driving is considered a non-impulsive 
source, while impact pile driving is treated as an impulsive source. 
DTH systems are considered to have both non-impulsive and impulsive 
components.
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). PTS does not 
generally affect more than a limited frequency range, and an animal 
that has incurred PTS has incurred some level of hearing loss at the 
relevant frequencies; typically animals with PTS are not functionally 
deaf (Richardson et al., 1995; Au and Hastings, 2008). Available data 
from humans and other terrestrial mammals indicate that a 40 dB 
threshold shift approximates PTS onset (Ward et al., 1958, Ward et al., 
1959; Ward, 1960; Kryter et al., 1966; Miller, 1974; Ahroon et al., 
1996; Henderson et al., 2008). PTS criteria for marine mammals are 
estimates, as with the exception of a single study unintentionally 
inducing PTS in a harbor seal (Kastak et al., 2008), there are no 
empirical data measuring PTS in marine mammals largely due to the fact 
that, for various ethical reasons, experiments involving anthropogenic 
noise exposure at levels inducing PTS are not typically pursued or 
authorized (NMFS, 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS, 2018). Based on data from cetacean TTS measurements 
(Southall et al., 2007; Southall et al., 2019), a TTS of 6 dB is 
considered the minimum threshold shift clearly larger than any day-to-
day or session-to-session variation in a subject's normal hearing 
ability (Schlundt et al., 2000; Finneran et al., 2000; Finneran et 
al.,2002). As described in Finneran (2015), marine mammal studies have 
shown the amount of TTS increases with SELcum in an accelerating 
fashion: at low exposures with lower SELcum, the amount of TTS is 
typically small and the growth curves have shallow slopes. At exposures 
with higher SELcum, the growth curves become steeper and approach 
linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Many studies have examined noise-induced hearing loss in marine 
mammals (see Finneran (2015) and Southall et al. (2019) for summaries). 
TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 2013). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. For 
cetaceans, published data on the onset of TTS are limited to captive 
bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis) (Southall et al., 2019). For pinnipeds in water, 
measurements of TTS are limited to harbor seals, elephant seals 
(Mirounga angustirostris), bearded seals (Erignathus barbatus), and 
California sea lions (Zalophus californianus) (Kastak et al., 1999; 
Kastak et al., 2007; Kastelein et al., 2019b; Kastelein et al., 2019c; 
Reichmuth et al., 2019; Sills et al., 2020; Kastelein et al., 2021; 
Kastelein et al., 2022a; Kastelein et al., 2022b). These studies 
examine hearing thresholds measured in marine mammals before and after 
exposure to intense or long-duration sound exposures. The difference 
between the

[[Page 78319]]

pre-exposure and post-exposure thresholds can be used to determine the 
amount of threshold shift at various post-exposure times.
    The amount and onset of TTS depends on the exposure frequency. 
Sounds at low frequencies, well below the region of best sensitivity 
for a species or hearing group, are less hazardous than those at higher 
frequencies, near the region of best sensitivity (Finneran and 
Schlundt, 2013). At low frequencies, onset-TTS exposure levels are 
higher compared to those in the region of best sensitivity (i.e., a low 
frequency noise would need to be louder to cause TTS onset when TTS 
exposure level is higher), as shown for harbor porpoises and harbor 
seals (Kastelein et al., 2019a; Kastelein et al., 2019c). Note that in 
general, harbor seals and harbor porpoises have a lower TTS onset than 
other measured pinniped or cetacean species (Finneran, 2015). In 
addition, TTS can accumulate across multiple exposures, but the 
resulting TTS will be less than the TTS from a single, continuous 
exposure with the same SEL (Mooney et al., 2009; Finneran et al., 2010; 
Kastelein et al., 2014; 2015). This means that TTS predictions based on 
the total, cumulative SEL will overestimate the amount of TTS from 
intermittent exposures, such as sonars and impulsive sources. 
Nachtigall et al. (2018) describe measurements of hearing sensitivity 
of multiple odontocete species (bottlenose dolphin, harbor porpoise, 
beluga, and false killer whale (Pseudorca crassidens) when a relatively 
loud sound was preceded by a warning sound. These captive animals were 
shown to reduce hearing sensitivity when warned of an impending intense 
sound. Based on these experimental observations of captive animals, the 
authors suggest that wild animals may dampen their hearing during 
prolonged exposures or if conditioned to anticipate intense sounds. 
Another study showed that echo-locating animals (including odontocetes) 
might have anatomical specializations that might allow for conditioned 
hearing reduction and filtering of low-frequency ambient noise, 
including increased stiffness and control of middle ear structures and 
placement of inner ear structures (Ketten et al., 2021). Data available 
on noise-induced hearing loss for mysticetes are currently lacking 
(NMFS, 2018). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans, but such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. PTS typically occurs at exposure levels at least 
several decibels above (a 40-dB threshold shift approximates PTS onset; 
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB 
threshold shift approximates TTS onset; e.g., Southall et al., 2007). 
Based on data from terrestrial mammals, a precautionary assumption is 
that the PTS thresholds for impulsive sounds (such as impact pile 
driving pulses as received close to the source) are at least 6 dB 
higher than the TTS threshold on a peak-pressure basis and PTS 
cumulative sound exposure level thresholds are 15 to 20 dB higher than 
TTS cumulative sound exposure level thresholds (Southall et al., 2007). 
Given the higher level of sound or longer exposure duration necessary 
to cause PTS as compared with TTS, it is considerably less likely that 
PTS could occur.
    Furthermore, installing piles for this project requires a 
combination of impact pile driving, vibratory pile driving, and DTH 
drilling. For the project, these activities would not occur at the same 
time and there would likely be pauses in activities producing the sound 
during each day. Given these pauses and that many marine mammals are 
likely moving through the action area and not remaining for extended 
periods of time, the potential for any TS declines.

Behavior Effects

    Exposure to noise from pile driving and removal also has the 
potential to behaviorally disturb marine mammals. Available studies 
show wide variation in response to underwater sound; therefore, it is 
difficult to predict specifically how any given sound in a particular 
instance might affect marine mammals perceiving the signal. If a marine 
mammal does react briefly to an underwater sound by changing its 
behavior or moving a small distance, the impacts of the change are 
unlikely to be significant to the individual, let alone the stock or 
population. However, if a sound source displaces marine mammals from an 
important feeding or breeding area for a prolonged period, impacts on 
individuals and populations could be significant (e.g., Lusseau and 
Bejder, 2007; Weilgart, 2007; NRC, 2005; Southall et al., 2021).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound 
are highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007, Southall et al. 2021; Weilgart, 2007; Archer et al., 2010). 
Behavioral reactions can vary not only among individuals but also 
within exposures of an individual, depending on previous experience 
with a sound source, context, and numerous other factors (Ellison et 
al., 2012; Southall et al., 2021), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). In 
general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. For a review of studies involving marine 
mammal behavioral responses to sound, see: Southall et al., 2007; Gomez 
et al., 2016; and Southall et al., 2021.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences 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.
    The area likely impacted by the project is relatively small 
compared to the available habitat in the surrounding waters of the Lynn 
Canal.

[[Page 78320]]

    In 2019, the White Pass & Yukon Route Railroad dolphin replacement 
project (84 FR 4777, February 19, 2019) documented observations of 
marine mammals during construction activities (i.e., pile driving) in 
Skagway, AK. This project was roughly 15 mi (24 km) from the proposed 
project site and features that are very similar (i.e. narrow inlet off 
the Lynn Canal). During the 57-day (March-May) protected species 
monitoring 26 killer whales and 2 humpback whales were observed 
traveling, diving, and swimming. There were 735 harbor seals and 165 
Steller sea lions observed during the monitoring period of the project. 
Harbor seals and Steller sea lions were observed travelling, swimming, 
playing, milling, traveling, resting, porpoising, looking, hauled out, 
sinking, and feeding (Owl Ridge Natural Resource Consultants, 2019). 
During the monitoring of the 2020 Alaska Marine Lines, Inc. dock in 
Lutak, AK (85 FR 22139, April 21, 2020) protected species observers 
(PSOs) recorded two Steller sea lions and one harbor seal in the Level 
B harassment zone. Both species spent less than 5 minutes in the zone 
(Tom Mortensen Associates, LLC, 2021). No visible signs of disturbance 
were noted for any of these species that were present in at either 
project. Given the similarities in activities and habitat and the fact 
the same species are involved, we expect similar behavioral responses 
of marine mammals to the specified activity. That is, disturbance, if 
any, is likely to be temporary and localized (e.g., small area 
movements).
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal that have the potential to cause behavioral harassment, 
depending on their distance from pile driving activities. Cetaceans are 
not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming near the project site within the range of noise levels 
exceeding the acoustic thresholds. We recognize that pinnipeds in the 
water could be exposed to airborne sound that may result in behavioral 
harassment when looking with their heads above water. Most likely, 
airborne sound would cause behavioral responses similar to those 
discussed above in relation to underwater sound. For instance, 
anthropogenic sound could cause pinnipeds to exhibit changes in their 
normal behavior, such as reduction in vocalizations, or cause them to 
temporarily abandon the area and move further from the source. However, 
these animals would previously have been ``taken'' because of exposure 
to underwater sound above the behavioral harassment thresholds, which 
are in all cases larger than those associated with airborne sound. 
Thus, the behavioral harassment of these animals is already accounted 
for in these estimates of potential take. Therefore, we do not believe 
that authorization of incidental take resulting from airborne sound for 
pinnipeds is warranted, and airborne sound is not discussed further 
here.

Marine Mammal Habitat Effects

    The proposed project would occur within the same footprint as 
existing marine infrastructure. The nearshore habitat where the 
proposed project would occur is an area of relatively high marine 
vessel traffic. Most marine mammals do not generally use the area 
within the immediate vicinity of the project area. Temporary, 
intermittent, and short-term habitat alteration may result from 
increased noise levels within the Level A and Level B harassment zones. 
Effects on marine mammals will be limited to temporary displacement 
from pile installation and removal noise, and effects on prey species 
will be similarly limited in time and space.
    Water Quality--Temporary and localized reduction in water quality 
will occur as a result of in-water construction activities. Most of 
this effect will occur during the installation and removal of piles and 
bedrock removal when bottom sediments are disturbed. The installation 
and removal of piles and bedrock removal will disturb bottom sediments 
and may cause a temporary increase in suspended sediment in the project 
area. During pile extraction, sediment attached to the pile moves 
vertically through the water column until gravitational forces cause it 
to slough off under its own weight. The small resulting sediment plume 
is expected to settle out of the water column within a few hours. 
Studies of the effects of turbid water on fish (marine mammal prey) 
suggest that concentrations of suspended sediment can reach thousands 
of milligrams per liter before an acute toxic reaction is expected 
(Burton, 1993).
    Impacts to water quality from DTH hammers are expected to be 
similar to those described for pile driving. Impacts to water quality 
would be localized and temporary and would have negligible impacts on 
marine mammal habitat. Effects to turbidity and sedimentation are 
expected to be short-term, minor, and localized. Since the currents are 
strong in the area, following the completion of sediment-disturbing 
activities, suspended sediments in the water column should dissipate 
and quickly return to background levels in all construction scenarios. 
Turbidity within the water column has the potential to reduce the level 
of oxygen in the water and irritate the gills of prey fish species in 
the proposed project area. However, turbidity plumes associated with 
the project would be temporary and localized, and fish in the proposed 
project area would be able to move away from and avoid the areas where 
plumes may occur. Therefore, it is expected that the impacts on prey 
fish species from turbidity, and therefore on marine mammals, would be 
minimal and temporary. In general, the area likely impacted by the 
proposed construction activities is relatively small compared to the 
available marine mammal habitat in southeast Alaska.

Effects on Prey

    Construction activities would produce continuous (i.e., vibratory 
pile driving) and impulsive (i.e., impact driving) sounds and a both 
continuous and impulsive sounds from DTH installation. Fish react to 
sounds that are especially strong and/or intermittent low-frequency 
sounds. Short duration, sharp sounds can cause overt or subtle changes 
in fish behavior and local distribution. Hastings and Popper (2005) 
identified several studies that suggest fish may relocate to avoid 
certain areas of sound energy. Additional studies have documented 
effects of pile driving on fish, although several are based on studies 
in support of large, multiyear bridge construction projects (e.g., 
Scholik and Yan, 2001, Scholik and Yan, 2002; Popper and Hastings, 
2009). Sound pulses at received levels may cause noticeable changes in 
behavior (Pearson et al., 1992; Skalski et al., 1992). SPLs of 
sufficient strength have been known to cause injury to fish and fish 
mortality.
    Impacts on marine mammal prey (i.e., fish or invertebrates) of the 
immediate area due to the acoustic disturbance are possible. The 
duration of fish or invertebrate avoidance or other disruption of 
behavioral patterns in this area after pile driving stops is unknown, 
but a rapid return to normal recruitment, distribution and behavior is 
anticipated. Further, significantly large areas of fish and marine 
mammal foraging habitat are available in the nearby vicinity in the 
Lynn Canal.
    The duration of the construction activities is relatively short, 
with pile driving and removal activities expected

[[Page 78321]]

last less than one-year. Each day, construction would occur for no more 
than 12 hours during the day and pile driving activities would be 
restricted to daylight hours. The most likely impact to fish from pile 
driving activities at the project area would be temporary behavioral 
avoidance of the area. In general, impacts to marine mammal prey 
species are expected to be minor and temporary due to the short 
timeframe for the project.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect fish in the project area. Increased 
turbidity is expected to occur in the immediate vicinity (on the order 
of 10 ft (3 m) or less) of construction activities. However, suspended 
sediments and particulates are expected to dissipate quickly within a 
single tidal cycle. Given the limited area affected and high tidal 
dilution rates any effects on fish are expected to be minor or 
negligible. In addition, best management practices would be in effect, 
which would limit the extent of turbidity to the immediate project 
area.
    In summary, given the relatively short daily duration of sound 
associated with individual pile driving and events and the relatively 
small areas being affected, pile driving activities associated with the 
proposed action are not likely to have a permanent, adverse effect on 
any fish habitat, or populations of fish species. Thus, we conclude 
that impacts of the specified activity are not likely to have more than 
short-term adverse effects on any prey habitat or populations of prey 
species. Further, any impacts to marine mammal habitat are not expected 
to result in significant or long-term consequences for individual 
marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization through the proposed 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 construction equipment (i.e., pile driving) 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, primarily for high frequency species and 
phocids, because predicted auditory injury zones are larger and beyond 
Haines Borough's capability to reasonably monitor. Auditory injury is 
unlikely to occur for other species groups, based on the combination of 
expected occurrence and monitoring capabilities relative to estimated 
Level A harassment zone sizes. 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 
provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the proposed take estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, Southall et al., 2021, Ellison et 
al., 2012). Based on what the available science indicates and the 
practical need to use a threshold based on a metric that is both 
predictable and measurable for most activities, NMFS typically uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS generally predicts that marine 
mammals are likely to be behaviorally harassed in a manner considered 
to be Level B harassment when exposed to underwater anthropogenic noise 
above root-mean-squared pressure received levels (RMS SPL) of 120 dB 
(referenced to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., 
vibratory pile driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources. Generally speaking, Level B 
harassment take estimates based on these behavioral harassment 
thresholds are expected to include any likely takes by TTS as, in most 
cases, the likelihood of TTS occurs at distances from the source less 
than those at which behavioral harassment is likely. TTS of a 
sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    Haines Borough's proposed activity includes the use of continuous 
(vibratory pile driving) and impulsive (impact pile driving) sources, 
and therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are 
applicable. DTH systems have both continuous and intermittent 
(impulsive) components as discussed in the Description of Sound Sources 
section above. When evaluating Level B harassment, NMFS recommends 
treating DTH as a continuous source and applying the RMS SPL thresholds 
of 120 dB re 1 [mu]Pa.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0 of 
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

[[Page 78322]]

types of sources (impulsive or non-impulsive). The Haines Borough's 
proposed construction includes the use of impulsive (impact pile 
driving) and non-impulsive (vibratory pile driving) sources. As 
described above, DTH includes both impulsive and non-impulsive 
characteristics. When evaluating Level A harassment, NMFS recommends 
treating DTH as an impulsive source.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset 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 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]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, DTH). The maximum (underwater) area 
ensonified above the thresholds for behavioral harassment referenced 
above is 20.86 km\2\ (12.96 mi\2\), and would consist of the entire 
area of Lutak Inlet (see Figure 20 in the Haines Borough's 
application). Additionally, vessel traffic and other commercial and 
industrial activities in the project area may contribute to elevated 
background noise levels which may mask sounds produced by the project.
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R1/R2),

where:

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

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6-dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]). A 
practical spreading value of 15 is often used under conditions, such as 
the project site, where water increases with depth as the receiver 
moves away from the shoreline, resulting in an expected propagation 
environment that would lie between spherical and cylindrical spreading 
loss conditions. Practical spreading loss is assumed here.
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. In order to calculate 
the distances to the Level A harassment and the Level B harassment 
sound thresholds for the methods and piles being used in this project, 
the applicant and NMFS used acoustic monitoring data from other 
locations to develop proxy source levels for the various pile types, 
sizes and methods. The project includes vibratory, impact, and DTH pile 
installation of steel pipe and sheet piles and vibratory removal of 
steel pipe piles. Source levels for 36 in steel piles are used as a 
proxy for 42 in steel piles, as 36 in source levels are higher than 
those available for 42 in piles. Using these higher values is the more 
conservative approach for mitigation measures and take estimate 
calculations. NMFS consulted multiple sources to determine valid proxy 
source levels for the impact installation of sheet piles, as indicated 
in table 5. This is the best available data for sheet pile source 
levels and is based on 24-in sheet piles used for a project in 
California. Source levels for each pile size and driving method are 
presented in table 5.

[[Page 78323]]



                                          Table 5--Proxy Sound Source Levels for Pile Sizes and Driving Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Proxy source level
                                                          ------------------------------------------------
             Pile size                      Method            dB RMS re       dB SEL re      dB peak re                  Literature source
                                                               1[mu]Pa      1[mu]Pa\2\sec      1[mu]Pa
--------------------------------------------------------------------------------------------------------------------------------------------------------
16 in.............................  Vibratory............             161             N/A             N/A  Navy 2015.
24 in.............................  Vibratory............             161             N/A             N/A  Navy 2015.
36 in.............................  Vibratory............             166             N/A             N/A  Navy 2015.
42 in.............................  Vibratory............             170             N/A             N/A  Illingworth and Rodkin, 2019.
55.5 in sheet pile................  Vibratory............             162             N/A             N/A  Molnar et al. 2020.
36 in.............................  Impact...............             192             184             211  Navy 2015.
42 in.............................  Impact...............             192             184             211  Navy 2015.
55.5 in sheet pile................  Impact...............             190             180             205  Caltrans 2015.
42 in.............................  DTH..................             174             164             194  NMFS 2022.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    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 impact or vibratory pile driving and removal 
and DTH, the optional User Spreadsheet tool predicts the distance at 
which, if a marine mammal remained at that distance for the duration of 
the activity, it would be expected to incur PTS. Inputs used in the 
optional User Spreadsheet tool, and the resulting estimated isopleths, 
are reported below. Inputs used in the optional User Spreadsheet tool 
(table 6), and the resulting estimated isopleths and the calculated 
Level B harassment isopleth (table 7), are reported below. For source 
levels of each pile please refer to Table 5.

                              Table 6--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Weighting factor  Number of strikes   Number  of piles  Activity duration
      Pile size and installation method            Spreadsheet tab used        adjustment (kHz)       per pile           per day           (minutes)
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-in vibratory removal.....................  A.1 Vibratory pile driving....                2.5                N/A                  4                 45
24-in vibratory removal.....................  A.1 Vibratory pile driving....                2.5                N/A                  1                 45
36-in vibratory installation (temporary)....  A.1 Vibratory pile driving....                2.5                N/A                  4                 15
36-in vibratory removal (temporary).........  A.1 Vibratory pile driving....                2.5                N/A                  4                 15
42-in vibratory installation................  A.1 Vibratory pile driving....                2.5                N/A                  4                 45
55-in sheet pile vibratory installation.....  A.1 Vibratory pile driving....                2.5                N/A                  6                 30
36-in impact installation (temporary).......  E.1 Impact pile driving.......                  2                900                  4                N/A
42-in impact installation...................  E.1 Impact pile driving.......                  2              1,500                  4                N/A
55-in sheet pile impact installation........  E.1 Impact pile driving.......                  2                900                  6                N/A
42-in DTH installation......................  E.2 DTH systems...............                  2            324,000                  2                N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                              Table 7--Calculated Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Level A harassment zone (m)                               Level B
                        Activity                         --------------------------------------------------------------------------------   harassment
                                                           LF-cetaceans    MF-cetaceans    HF-cetaceans       Phocids        Otariids        zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-in vibratory removal.................................            14.2             1.3            21.8             8.6             0.6           5,412
24-in vibratory removal.................................             5.6             0.5             8.3             3.4             0.2
36-in vibratory installation (temporary)................            14.7             1.3            21.8             8.9             0.6          11,659
36-in vibratory removal (temporary).....................            14.7             1.3            21.8             8.9             0.6
42-in vibratory installation............................            42.9             3.8            63.4            26.1             1.8          16,343
55-in sheet pile vibratory installation.................            16.6             1.5            24.5            10.1             0.7           6,310
36-in impact installation (temporary)...................         2,734.9            97.3         3,257.7         1,463.6           106.6           1,359
42-in impact installation...............................         3,844.5           136.7         4,579.4         2,057.4           149.8           1,359
55-in sheet pile impact installation....................         1,939.4            69.0         2,310.1         1,037.9            75.6           1,000
42-in DTH installation..................................         4,046.9           143.9         4,820.5         2,165.7           157.7          39,811
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 78324]]

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations.
    When available, peer-reviewed scientific publications were used to 
estimate marine mammal abundance in the project area. Data from 
monitoring reports from previous projects in Lutak and Skagway were 
used. However, scientific surveys and resulting data, such as 
population estimates, densities, and other quantitative information, 
are lacking for some marine mammal populations and most areas of 
southeast Alaska, including Lutak Inlet. Therefore, Haines Borough 
additionally gathered qualitative information from discussions with 
knowledgeable local people in the Lutak area. Assumptions regarding the 
size of expected groups of different species, and the frequency of 
occurrence of those groups, were proposed by Haines Borough on the 
basis of the aforementioned information. NMFS has reviewed the 
available information and concurs that these choices are reasonable.
    Here we describe how the information provided is synthesized to 
produce a quantitative estimate of the take that is reasonably likely 
to occur and proposed for authorization. Since reliable densities are 
not available, the take numbers are based on the assumed maximum number 
of animals in a group at a given time and the occurrence of those 
groups per day multiplied by the duration of each activity. Tables for 
each species are presented to show the calculation of take during the 
project. The take calculation for this project is:

Incidental take estimate = number of individuals in a group * groups 
per day * days of pile-related activity

Humpback Whale

    Humpback whale presence in Lutak is irregular year-round. From mid-
May through September whales are assumed to occur in groups of two and 
from October to April in groups of one. It is expected that in early 
summer (mid-May through July) one group every two days may occur and at 
all other times of the year one group every 10 days would occur in the 
project area (Solstice AK, 2023 and Happywhale, 2023). Therefore, using 
the equation given above, the total number of Level B harassment takes 
for humpback whales would be 26. Given that 2 percent of the humpback 
whales in southeast Alaska are expected to be members of the Mexico 
stock (Wade et al., 2016), one take is assumed to be from the Mexico 
stock and 25 takes from the Hawaii stock.
    The largest Level A harassment zone for humpback whales extends 
4,050 m from the noise source (table 9). All construction work would be 
shut down prior to a humpback whale entering the Level A harassment 
zone specific to the in-water activity underway at the time. In 
consideration of the infrequent occurrence of humpback whales in the 
project area and proposed shutdown requirements, no take by Level A 
harassment is anticipated or proposed for humpback whales.

Killer Whale

    Killer whales occur in the Lutak Inlet year round with higher 
occurrences in the spring. Group sizes of 15 animals are expected with 
1 group every 20 days from mid-March through May and 1 group every 30 
days for the remainder of the year (Hart Crowser, Inc. and KPFF 
Consulting Engineers 2016). There are three stocks of killer whales 
that may be present in the project area, with the following proportions 
of overall killer whale occurrence expected: Alaska Residents, 75 
percent; West Coast Transients, 13 percent; and Northern Residents, 12 
percent (Section 6 of the IHA application). The applicant estimated 
these occurrence proportions by determining the total number of animals 
in all three stocks and dividing that number by the number of animals 
in a given stock. Therefore, with 130 expected total takes by Level B 
harassment, 103 takes are expected to be from the Alaska Resident 
stock, 19 takes are expected from the West Coast Transient stock, and 
16 takes are expected from the Northern Resident stock.
    The largest Level A harassment zone for killer whales extends 150 
meters from the noise source (table 9). Killer whales are generally 
conspicuous and protected species observers (PSO) are expected to 
detect killer whales and implement a shutdown before the animals enter 
the Level A harassment zone. Therefore, takes by Level A harassment are 
not anticipated or proposed to be authorized.

Harbor Porpoise

    Harbor porpoise are present year round in the Lynn Canal and are 
expected to be present in groups of two every 30 days at the project 
site. Haines Borough requested a total of 29 takes of harbor porpoise 
for the duration of the project. Of the 29 takes it is expected that 13 
of those takes could be by Level A harassment, over 153 days of impact 
installation of 36-in, 42-in, and 55-in sheet piles and DTH activities. 
For construction activities that are of short duration and the take 
estimate was below the expected group size, the expected group size 
(e.g., two animals) was used as a proxy for take calculations for those 
activities. The remaining 16 takes would are expected to be by Level B 
harassment.
    Harbor porpoises are known to be an inconspicuous species and are 
challenging for protected species observers (PSOs) to sight, making any 
approach to a specific area potentially difficult to detect. The 
largest Level A harassment zone results from impact driving of 42-in 
piles, and extends 4,820.5 m from the source for high frequency 
cetaceans (table 7). We propose a distance of 200 m as an effective 
shutdown zone, given the difficulty of observing harbor porpoise at 
greater distances (see Proposed Mitigation section). Therefore, some 
take by Level A harassment is expected.

Dall's Porpoise

    Groups of four Dall's porpoise are expected to occur once every 30 
days during the proposed project (Dahlheim et al., 2009), resulting in 
an estimate of 31 takes by Level B harassment. Although no Dall's 
porpoise were observed during recent monitoring of other projects in 
the area, tour boat operators occasionally observe Dall's porpoise in 
Taiya Inlet (SolsticeAK, 2023). Therefore, the applicant has requested 
authorization of take as described above. NMFS concurs with this 
request and proposes to authorize the take.
    The largest Level A harassment zone for Dall's porpoise extends 
4,820.5 m from the source during DTH installation of 42-in piles (table 
7). Although Haines Borough would implement a significantly smaller 
shutdown zone (i.e., 200-m), given the low likelihood of occurrence of 
Dall's porpoises in the area take by Level A harassment is not 
anticipated and is not proposed to be authorized.

Steller Sea Lion

    Steller sea lions are frequently observed in the project area. 
Group sizes vary during seasonal fish runs in the area. Groups of 40 
animals per day are expected from mid-March through May when animals 
frequent the project site, including the Taiya point haulout. At other 
times of the year groups of 2 animals per day are expected in the 
project area.
    During the impact installation of 36-in and 42-in piles and the DTH 
installation of 42-in piles, groups of 2 sea lions per day are expected 
to occur within the respective Level A

[[Page 78325]]

harassment zones over 146 days associated with these activities. On 
this basis, we propose to authorize 292 takes of Steller sea lions by 
Level A harassment. Given that 1.4 percent of Steller sea lions are 
members of the ESA listed western DPS in the project area, 4 of the 292 
takes by Level A harassment would likely be western DPS individuals. 
The largest Level A harassment zone for Steller sea lions is 150 m 
(table 7) but it may be difficult for PSOs to view Steller sea lions at 
the outer edges of the zone and therefore some take by Level A 
harassment is expected.
    Larger harassment zones associated with Level B harassment would 
encompass the Taiya point haulout. It is expected that groups of 40 
Steller sea lions per day over 75 days of vibratory installation of all 
pile types, impact installation of 36-in and 42-in piles, and DTH 
installation of 42-in piles which would equate to 3,000 takes by Level 
B harassment. At other times of the year when the Taiya point haulout 
is not used group size would be two sea lions per day. During this 
period the applicant would complete work over 151 days for vibratory 
installation of all pile types, impact installation of 36-in and 42-in 
piles, and DTH installation of 42-in piles which would equate to 302 
takes by Level B harassment.

Harbor Seal

    Harbor seals are common in the project area year round. The 
applicant expects groups of 100 animals from March through May when 
animals are more frequent feeding at the mouth of the Chilkoot River. 
At other times of the year groups of five animals are expected in the 
project area (SolsticeAK 2023).
    During impact installation of 36-in, 42-in, and 55-in sheet piles 
and DTH installation of 42-in piles it is expected that one group of 
five harbor seals every 10 days would occur. Over 153 days of activity 
79 total takes by Level A harassment may occur. For construction 
activities that are of short duration and the take estimate was below 
the expected group size, the expected group size (e.g. five animals) 
was used as a proxy for take calculations for those activities. The 
largest Level A harassment zone results from impact driving of 42-in 
piles, and extends 2,057 m from the source for phocids (table 7). We 
propose a distance of 200 m as an effective shutdown zone, given the 
difficulty of observing harbor seals at greater distances (see Proposed 
Mitigation section). Therefore, take by Level A harassment is expected.
    Similar to Steller sea lions the larger Level B harassment zones 
would encompass the mouth of the Chilkoot River where larger 
aggregations of harbor seals are known to occur. It is expected that 
groups of harbor seals of 100 every 10 days over 75 days of vibratory 
installation of all pile types, impact installation of all pile types, 
and DTH installation of 42-in piles, which would equate to 750 takes by 
Level B harassment. During other times of the year the applicant 
expects groups of five animals every 10 days over a 151 day period for 
vibratory installation of all pile types, impact installation of 36-in 
and 42-in piles, and DTH installation of 42-inch piles. This would 
result in 827 takes by Level B harassment.

                                     Table 8--Estimated Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                           Proposed take
                Common name                             Stock                  Stock          Level A         Level B     Total proposed       as a
                                                                           abundance \a\                                       take         percentage
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback Whale............................  Mexico......................             UKN               0               1               1             N/A
                                            Hawaii......................          11,278               0              25              25             0.2
Killer Whale..............................  Alaska Resident.............           1,920               0             103             103             5.4
                                            West Coast Transients.......             349               0              19              19             5.4
                                            Eastern North Pacific                    302               0              16              16             5.3
                                             Northern Residents.
Harbor Porpoise...........................  Northern Southeast Alaska...           1,619              13              16              29             1.8
Dall's Porpoise...........................  Alaska......................             UKN               0              31              31             N/A
Steller sea lion..........................  Western DPS.................          52,932               4              33              37           < 0.1
                                            Eastern DPS.................          43,201             288           2,319           2,607             6.0
Harbor Seal...............................  Lynn Canal/Stephens Passage.          13,388              79             827             906             6.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Stock or DPS size is Nbest according to NMFS 2022 Final Stock Assessment Reports.

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance. 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. 
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.
    The following measures would apply to Haines Borough's mitigation 
requirements:
    Implementation of Shutdown Zones--For all pile driving/removal 
activities, Haines Borough would implement shutdowns within designated 
zones. The purpose of a shutdown zone is generally to define an area 
within which

[[Page 78326]]

shutdown of activity would occur upon sighting of a marine mammal (or 
in anticipation of an animal entering the defined area). Implementation 
of shutdowns would be used to avoid or minimize incidental Level A 
harassment takes from vibratory, impact, and DTH pile removal and 
installation (Table 8). For all pile driving/removal activities, a 
minimum 10-m shutdown zone must be established. NMFS has recommended 
shutdown zones of 200 m for high-frequency cetaceans and phocids, 
despite significantly larger estimated Level A harassment zones, in 
order to prescribe implementation of a zone that may be reasonably 
observed under typical conditions for these cryptic species. It is 
reasonable to expect that these species would be difficult to detect 
from distances further than 200 m by PSOs (table 9). All other shutdown 
zones for pile driving and removal activities are based on the Level A 
harassment zones and therefore vary by pile size and marine mammal 
hearing group (table 9). The placement of PSOs during all pile driving 
activities (described in detail in the Monitoring and Reporting 
section) would ensure the full extent of shutdown zones are visible to 
PSOs.

                                              Table 9--Shutdown Zones During Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                Shutdown zones (m)
                                                        Minutes or strikes   Piles per  ----------------------------------------------------------------
            Activity                   Pile size             per pile           day           LF           MF           HF
                                                                                          cetaceans    cetaceans    cetaceans     Phocids      Otariids
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Removal...............  16-in..............  45 min.............            4           15           10           30           10           10
                                                                                        ----------------------------------------------------------------
                                  24-in..............  45 min.............            1                                 10
                                                                                        ----------------------------------------------------------------
                                  36-in (temporary)..  15 min.............            4           15           10           30           10           10
Vibratory Installation..........  36-in (temporary)..  15 min.............            4           15           10           30           10           10
                                  42-in..............  45 min.............            4           60           10           85           35           10
                                  55-in sheet pile...  30 min.............            6           20           10           25           10           10
Impact Installation.............  36-in (temporary)..  900 strikes........            4        2,735          110          200          200          110
                                  42-in..............  1,500 strikes......            4        3,845          150                                    150
                                  55-in sheet pile...  900 strikes........            6        1,940           70                                     80
DTH drilling....................  42-in..............  300 min/324,000                2        4,050          145                                    160
                                                        strikes.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Establishment of Monitoring Zones--Haines Borough has identified 
monitoring zones correlated with the larger of the Level B harassment 
or Level A harassment zones. Monitoring zones provide utility for 
observing by establishing monitoring protocols for areas adjacent to 
the shutdown zones. In some cases the calculated monitoring zones are 
smaller than the Level A shutdown zones as presented in table 10. This 
is due to the project area being bounded by land to 7,000 m on the 
western most shore of the inlet and 5,820 m on the eastern shore. 
Monitoring zones enable observers to be aware of and communicate the 
presence of marine mammals in the project area outside the shutdown 
zone and thus prepare for a potential cessation of activity should the 
animal enter the shutdown zone. PSOs would monitor the entire visible 
area to maintain the best sense of where animals are moving relative to 
the zone boundaries defined in tables 9 and 10. Placement of PSOs on 
the shorelines around Lutak Inlet allow PSOs to observe marine mammals 
within and near the inlet. The applicant may also voluntarily place a 
PSO on a skiff in Taiya Inlet if safe conditions allow for such 
activity.

                 Table 10--Marine Mammal Monitoring Zone
------------------------------------------------------------------------
                                                        Monitoring zone
                       Activity                               (m)
------------------------------------------------------------------------
Vibratory removal of 16-in and 24-in piles...........              5,425
Vibratory installation and removal of 36-in temporary              7,000
 piles...............................................
Vibratory installation of 42-in piles................              7,000
Vibratory installation of 55-in sheet piles..........              6,310
Impact installation of 36-in temporary piles.........            * 1,360
Impact installation of 42-in piles...................            * 1,360
Impact installation of 55-in sheet piles.............              1,000
DTH installation of 42-in piles......................              7,000
------------------------------------------------------------------------
* Where Level A shutdown zones are larger than the Level B harassment
  zones.

    Soft Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
would be required to provide an initial set of strikes from the hammer 
at reduced energy, with each strike followed by a 30-second waiting 
period. This procedure would be conducted a total of three times before 
impact pile driving begins. 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. 
Soft start is not required during vibratory pile driving and removal 
activities.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal 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 zone, a soft-start cannot proceed until the animal 
has left the zone or has not been observed for 15 minutes. If the 
monitoring zone has been observed for 30 minutes and marine mammals are 
not present within the zone, soft-start procedures can commence and 
work can continue even if visibility becomes impaired within the 
monitoring zone. When a marine mammal permitted for take by Level B 
harassment is present in the Level B harassment zone, activities may 
begin. No work may begin unless the entire shutdown zone is visible to 
the PSOs. If work ceases for more than 30 minutes, the pre-activity 
monitoring of both the monitoring zone and shutdown zone would 
commence.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the

[[Page 78327]]

proposed mitigation measures provide the means of effecting the least 
practicable impact on the affected species or stocks and their habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance.

Proposed Monitoring and Reporting

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

Visual Monitoring

    Monitoring shall be conducted by NMFS-approved observers in 
accordance with the monitoring plan (Appendix C of the IHA application) 
and Section 5 of the IHA. Trained observers shall be placed from the 
best vantage point(s) practicable to monitor for marine mammals and 
implement shutdown or delay procedures when applicable through 
communication with the equipment operator. Observer training must be 
provided prior to project start, and shall include instruction on 
species identification (sufficient to distinguish the species in the 
project area), description and categorization of observed behaviors and 
interpretation of behaviors that may be construed as being reactions to 
the specified activity, proper completion of data forms, and other 
basic components of biological monitoring, including tracking of 
observed animals or groups of animals such that repeat sound exposures 
may be attributed to individuals (to the extent possible).
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal activities. In addition, observers 
shall record all incidents of marine mammal occurrence, regardless of 
distance from activity, and shall document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving/
removal activities include the time to install or remove a single pile 
or series of piles, as long as the time elapsed between uses of the 
pile driving equipment is no more than 30 minutes.
    A minimum of one PSO would be on duty during all barge movements 
and other in-water construction activities and a minimum of three PSOs 
during all pile driving activities. Locations from which PSOs would be 
able to monitor for marine mammals are readily available from publicly 
accessible shore side areas at the project site, Lutak Road at a beach 
across from Takshanuk Mountain trail, and along the shoreline just 
south of Tanani Point along Lutak Road. PSOs would monitor for marine 
mammals entering the harassment zones.
    PSOs would scan the waters using binoculars and would use a 
handheld range-finder device to verify the distance to each sighting 
from the project site. All PSOs would be trained in marine mammal 
identification and behaviors and are required to have no other project-
related tasks while conducting monitoring. In addition, monitoring 
would be conducted by qualified observers, who would be placed at the 
best vantage point(s) practicable to monitor for marine mammals and 
implement shutdown/delay procedures when applicable by calling for the 
shutdown to the hammer operator via a radio. Haines Borough would 
adhere to the following observer qualifications:
    (i) PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
    (ii) One PSO would be designated as the lead PSO or monitoring 
coordinator and that observer must have prior experience working as an 
observer;
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience; and
    (iv) Haines Borough must submit observer Curriculum Vitaes for 
approval by NMFS.
    Additional recommended observer qualifications include:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.

Reporting

    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities. It would include an overall description of work completed, 
a narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring;

[[Page 78328]]

     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 driving) and for each pile or 
total number of strikes for each pile (impact driving);
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information: Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting; time of sighting; identification of the 
animal(s) (e.g., genus/species, lowest possible taxonomic level, or 
unidentified), PSO confidence in identification, and the composition of 
the group if there is a mix of species; distance and bearing of each 
marine mammal observed relative to the pile being driven for each 
sighting (if pile driving was occurring at time of sighting); estimated 
number of animals (min/max/best estimate); estimated number of animals 
by cohort (adults, juveniles, neonates, group composition, etc.); 
animal's closest point of approach and estimated time spent within the 
harassment zone; description of any marine mammal behavioral 
observations (e.g., observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g., no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
     Number of marine mammals detected within the harassment 
zones, by species; and
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
final report would constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

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

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338; 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the majority of our analysis applies to all 
the species listed in table 8, given that many of the anticipated 
effects of this project on different marine mammal stocks are expected 
to be relatively 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, they are described independently in the analysis below.
    Pile driving and removal activities associated with the project as 
outlined previously, have the potential to disturb or displace marine 
mammals. Specifically, the specified activities may result in take, in 
the form of Level A harassment and Level B harassment from underwater 
sounds generated from

[[Page 78329]]

pile driving and removal. Potential takes could occur if individuals of 
these species are present in zones ensonified above the thresholds for 
Level A or Level B harassment identified above when these activities 
are underway.
    Take by Level A and Level B harassment would be due to potential 
behavioral disturbance, TTS, and PTS. No serious injury or mortality is 
anticipated or proposed for authorization given the nature of the 
activity and measures designed to minimize the possibility of injury to 
marine mammals. Take by Level A harassment is only anticipated for 
harbor porpoise, Steller sea lions, and harbor seal. Take by Level A 
harassment of the ESA-listed western DPS of Steller sea lions is 
expected to be a very small portion of the overall DPS (<0.1 percent). 
Impacts to affected individuals of the western DPS are not expected to 
result in population-level impacts. The potential for harassment is 
minimized through the construction method (i.e. use of direct pull 
removal or vibratory methods to the extent practical) and the 
implementation of the planned mitigation measures (see Proposed 
Mitigation section).
    In addition to the expected effects resulting from Level B 
harassment, we anticipate that harbor porpoises, Steller sea lions, and 
harbor seals may sustain some limited Level A harassment in the form of 
auditory injury. However, animals in these locations that experience 
PTS would likely only receive slight PTS, i.e., minor degradation of 
hearing capabilities within regions of hearing that align most 
completely with the energy produced by pile driving, i.e., the low-
frequency region below 2 kHz, not severe hearing impairment or 
impairment in the regions of greatest hearing sensitivity. If hearing 
impairment occurs, it is most likely that the affected animal would 
lose a few decibels in its hearing sensitivity, which in most cases is 
not likely to meaningfully affect its ability to forage and communicate 
with conspecifics. As described above, we expect that marine mammals 
would be likely to move away from a sound source that represents an 
aversive stimulus, especially at levels that would be expected to 
result in PTS, given sufficient notice through use of soft start.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may cause some fish or invertebrates to 
leave the area of disturbance, thus temporarily impacting marine 
mammals' foraging opportunities in a limited portion of the foraging 
range; but, because of the short duration of the activities, the 
relatively small area of the habitat that may be affected, and the 
availability of nearby habitat of similar or higher value, the impacts 
to marine mammal habitat are not expected to cause significant or long-
term negative consequences. The haulout location at Taiya Point would 
be affected by the project for foraging Steller sea lions and 
occasionally harbor seals. Currently, the Taiya Point haulout location 
is not known to be a pupping location for Steller sea lions or harbor 
seals but are important areas throughout the year. Steller sea lions 
and to a lesser extent harbor seals at this haulout would likely result 
in repeated exposure of the same animals. Repeated exposures of 
individuals to this pile driving activity could cause Level A and Level 
B harassment but are unlikely to considerably disrupt foraging behavior 
or result in significant decrease in fitness, reproduction, or survival 
for the affected individuals.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect any of the species 
or stocks through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Any Level A harassment exposures (i.e., to harbor seals, 
harbor porpoise, and Steller sea lions, only) are anticipated to result 
in slight PTS (i.e., of a few decibels), within the lower frequencies 
associated with pile driving;
     The anticipated incidents of Level B harassment would 
consist of, at worst, temporary modifications in behavior that would 
not result in fitness impacts to individuals;
     The ensonifed areas from the project are very small 
relative to the overall habitat ranges of all species and stocks;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat or any other areas of known biological 
importance; with the exception of the haulout location at Taiya Point; 
and
     The proposed mitigation measures are expected to reduce 
the effects of the specified activity to the level of least practicable 
adverse impact.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    Table 8 demonstrates the number of animals that could be exposed to 
the received noise levels that could cause harassment for the proposed 
work in Lutak Inlet. Our analysis shows that less than 6.8 percent of 
each affected stock could be taken by harassment. The numbers of 
animals proposed to be taken for these stocks would be considered small 
relative to the relevant stock's abundances, even if each estimated 
taking occurred to a new individual--an extremely unlikely scenario.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals would be taken relative to the population 
size of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by (i) causing the 
marine mammals to abandon or avoid

[[Page 78330]]

hunting areas, (ii) directly displacing subsistence users, or (iii) 
placing physical barriers between the marine mammals and the 
subsistence hunters, and (2) that cannot be sufficiently mitigated by 
other measures to increase the availability of marine mammals to allow 
subsistence needs to be met.
    In the Haines area sea lions and harbor seals are available for 
subsistence harvest under the MMPA. Limited subsistence harvests of 
marine mammals near the community of Haines has occurred in the past, 
with the most recent recorded/documented harvests of marine mammals in 
Haines in 2012 and in nearby Klukwan in 2014. The proposed activity 
will take place in Lutak Inlet, and no activities overlap with current 
subsistence hunting areas; therefore, there are no relevant subsistence 
uses of marine mammals adversely impacted by this action. The proposed 
project is not likely to adversely impact the availability of any 
marine mammal species or stocks that are commonly used for subsistence 
purposes or to impact subsistence harvest of marine mammals in the 
region.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the proposed mitigation and 
monitoring measures, NMFS has preliminarily determined that there will 
not be an unmitigable adverse impact on subsistence uses from Haines 
Borough'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 Mexico DPS of humpback 
whales and western DPS of Steller sea lions, which are listed under the 
ESA.
    The Office of Protected Resources has requested initiation of 
section 7 consultation with the Alaska Regional Office for the issuance 
of this IHA. NMFS will conclude the ESA consultation prior to reaching 
a determination regarding the proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to Haines Borough for conducting pile driving and removal 
activities in, Lutak Alaska from 1-year of the date of issuance of the 
final IHA, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated. A draft of the proposed 
IHA can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this notice of proposed IHA for the proposed 
action. We also request comment on the potential renewal of this 
proposed IHA as described in the paragraph below. Please include with 
your comments any supporting data or literature citations to help 
inform decisions on the request for this IHA or a subsequent renewal 
IHA.
    On a case-by-case basis, NMFS may issue a one-time, 1-year renewal 
IHA following notice to the public providing an additional 15 days for 
public comments when (1) up to another year of identical or nearly 
identical activities as described in the Description of Proposed 
Activity section of this notice is planned or (2) the activities as 
described in the Description of Proposed Activity section of this 
notice would not be completed by the time the IHA expires and a renewal 
would allow for completion of the activities beyond that described in 
the Dates and Duration section of this notice, provided all of the 
following conditions are met:
     A request for renewal is received no later than 60 days 
prior to the needed renewal IHA effective date (recognizing that the 
renewal IHA expiration date cannot extend beyond 1-year from expiration 
of the initial IHA); and
     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); 
and
    (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: November 8, 2023.
Shannon Bettridge,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2023-25097 Filed 11-14-23; 8:45 am]
BILLING CODE 3510-22-P