Notice2023-25097
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Lutak Dock Replacement Project, Haines Borough, Alaska
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
November 15, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
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 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.
Full Text
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<title>Federal Register, Volume 88 Issue 219 (Wednesday, November 15, 2023)</title>
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[Federal Register Volume 88, Number 219 (Wednesday, November 15, 2023)]
[Notices]
[Pages 78310-78330]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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 <a href="/cdn-cgi/l/email-protection#2c65787c024f434f475e4940406c42434d4d024b435a"><span class="__cf_email__" data-cfemail="0c45585c226f636f677e6960604c62636d6d226b637a">[email protected]</span></a>. 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:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>. 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 <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a> 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
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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; <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
[[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)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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)
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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
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Order Carnivora--Pinnipedia
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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).
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(<a href="https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; 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. <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports/">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports/</a>. 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:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
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 * Log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>),
where:
TL = transmission loss in dB
B = transmission loss coefficient
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = 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:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> 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);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> 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:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> 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
<bullet> 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:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
[[Page 78328]]
<bullet> 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);
<bullet> PSO locations during marine mammal monitoring;
<bullet> 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;
<bullet> 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);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> 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:
<bullet> Description of the incident;
<bullet> Environmental conditions (e.g., Beaufort sea state,
visibility);
<bullet> Description of all marine mammal observations in the 24
hours preceding the incident;
<bullet> Species identification or description of the animal(s)
involved;
<bullet> Fate of the animal(s); and
<bullet> 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:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> 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;
<bullet> 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;
<bullet> The ensonifed areas from the project are very small
relative to the overall habitat ranges of all species and stocks;
<bullet> 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
<bullet> 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>.
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:
<bullet> 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
<bullet> 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
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</html>Indexed from Federal Register on November 15, 2023.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.