Notice2025-06437
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the City of Ketchikan's Berth III Mooring Dolphins Project in Ketchikan, Alaska
Primary source
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Published
April 16, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the City of Ketchikan (COK), Alaska, for authorization to take marine mammals incidental to the Berth III Mooring Dolphins Project in the Port of Ketchikan in the Tongass Narrows, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS requests comments on its proposal to issue an incidental harassment authorization (IHA) to incidentally take marine mammals during the specified activities. NMFS also requests 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 before making any final decision on issuing 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 90 Issue 72 (Wednesday, April 16, 2025)</title>
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[Federal Register Volume 90, Number 72 (Wednesday, April 16, 2025)]
[Notices]
[Pages 15957-15977]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-06437]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE698]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the City of Ketchikan's Berth III
Mooring Dolphins Project in Ketchikan, 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 the City of Ketchikan (COK),
Alaska, for authorization to take marine mammals incidental to the
Berth III Mooring Dolphins Project in the Port of Ketchikan in the
Tongass Narrows, Alaska. Pursuant to the Marine Mammal Protection Act
(MMPA), NMFS requests comments on its proposal to issue an incidental
harassment authorization (IHA) to incidentally take marine mammals
during the specified activities. NMFS also requests 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 before making any final decision on issuing
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 May 16,
2025.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service, and should be submitted via email to
<a href="/cdn-cgi/l/email-protection#f7bea3a7d9b085969f969ab799989696d9909881"><span class="__cf_email__" data-cfemail="501904007e17223138313d103e3f31317e373f26">[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 below.
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/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</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: Krista Graham, 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
[[Page 15958]]
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 would have a negligible impact on the species or
stock(s) and would not have an unmitigable adverse effect 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 monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms used above are included in the relevant sections below.
They can be found in section 3 of the MMPA (16 U.S.C. 1362) and NMFS
regulations at 50 CFR 216.103.
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)
concerning 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.
Summary of Request
On July 17, 2024, NMFS received a request from the applicant (COK)
for an IHA to take marine mammals incidental to construction activities
associated with the project. Following NMFS' application review, COK
submitted a revised version on October 16, 2024. Following additional
NMFS questions and COK's subsequent responses, COK submitted a final
revised application on February 7, 2025. The application was deemed
adequate and complete on February 24, 2025. The COK requests to take 13
species (16 stocks) of marine mammals by Level B harassment, and a
limited number of individuals from 8 of those stocks by Level A
harassment. Neither COK nor NMFS expects serious injury or mortality
from this activity; therefore, an IHA is appropriate.
This proposed IHA would be the fourth IHA issued to COK for the
Berth III Mooring Dolphins Project. NMFS initially issued an IHA to COK
for the Berth III Mooring Dolphins Project on March 3, 2021 (86 FR
12411), effective from October 1, 2021, through September 30, 2022. The
reissued IHA (September 10, 2021, 86 FR 50704) was effective from
October 1, 2022, through September 30, 2023. The third IHA (December 8,
2022, 87 FR 75233) was effective from October 1, 2023, through
September 30, 2024. Due to COVID-19 pandemic-related tourism and
funding delays, COK did not start construction, and no work was
conducted under any of the three previous IHAs. For this fourth
proposed IHA, project details have been revised slightly, new sound
source information is available, and additional species not previously
included have been added. The effective dates of this proposed IHA
would be from October 1, 2025, through September 30, 2026.
Description of Proposed Activity
Overview
The purpose of the COK's Berth III construction expansion project
is to accommodate a new fleet of large cruise ships (i.e., Bliss class)
and to meet the needs of the growing cruise ship industry and its
vessels in Southeast Alaska. To safely moor a Bliss class vessel,
additional tie-up locations are needed at the north and south ends of
the berth. Without the proposed improvements, vessels may be unable to
safely moor at Berth III, located on the east side of Tongass Narrows,
which consists of an 11-mile-long, narrow body of water.
Construction activities would include erecting temporary weather
structures and templates, vibratory pile driving and removal, impact
pile driving, down-the-hole (DTH) pile driving, pile splicing, pile-to-
dolphin cap welding, and setting a catwalk. The underwater sound
generated by these in-water activities may result in Level A and Level
B harassment of marine mammal species.
Dates and Duration
Construction is expected to occur between October 1, 2025, and May
1, 2026. In-water work is estimated to take approximately 166 days (5.5
months or approximately 24 weeks) between October 1, 2025, and March
15, 2026. Above-water work is required to install prefabricated steel
dolphin caps and an approximately 66-ft prefabricated grated catwalk.
The daily duration of construction activities would vary based on the
daylight hours available. In the winter, shorter 7- to 10-hour workdays
in available daylight are anticipated; in the early fall and early
spring, longer daylight workdays of up to 12-hours are expected
(however, 14 hours of noise-generating activity is used in the
application for conservative isopleth calculations). While COK may work
these hours, not all activity in a workday would generate in-water
noise. Work may not begin without sufficient daylight to conduct pre-
activity monitoring and may extend into twilight hours as needed to
embed the pile far enough to leave piles in place until installation
can resume safely.
Specific Geographic Region
COK is located in Southeast Alaska on the western coast of
Revillagigedo Island, near the southernmost boundary of Alaska.
Ketchikan encompasses approximately 3 square miles (sq mi) of land (7.8
square kilometers (km\2\)) and 1 sq mi of water (2.6 km\2\). The site
is located on the east side of Tongass Narrows, a marine channel
between Revillagigedo and Gravina Islands, consisting of a long, narrow
water body approximately 11 miles (17.7 km) (see figure 1). The berth
is part of the Port of Ketchikan, an active marine commercial and
industrial area.
At the project site where piles would be driven, water depths range
between approximately 60 feet (ft) (18.3 meters (m)) to 160 ft (48.8 m)
(Peratrovich and Nottingham Engineers, Inc. (PND) 2006). Tidal currents
generally range from 0.3 miles (0.5 km) to 1.6 miles (2.6 km) per hour
during flood and ebb tides (PND 2006). The tide range in Ketchikan is
significant, with the highest observed tides of 21.4 ft (6.5 m) and the
lowest observed tides of -5.2 ft (-1.6 m), based on a mean lower low
water (MLLW) elevation of 0.0 ft (0 m). Water depths in Tongass Narrows
that would be ensonified are generally 160 ft (48.8 m) or shallower,
but they get deeper past the southern end of Pennock Island, reaching
depths up to 625 ft (190.5 m) (NOAA 2015).
[[Page 15959]]
[GRAPHIC] [TIFF OMITTED] TN16AP25.002
Detailed Description of the Specified Activity
The proposed project would install three new mooring dolphins (MD),
with one at the north end of Berth III (MD#2) and two at the south end
(MD#3 & MD#4), as shown in figure 2 in COK's IHA application (available
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>). A
total of 28 piles would be installed. Sixteen are temporary template
piles and would be removed, as shown in table 1. Pile driving would be
conducted from an anchored barge, using vibratory and impact hammers to
install and remove piles. Due to limited overburden, DTH pile
installation would be used to install rock sockets and tension anchors.
A maximum of one pile per day would be installed.
Table 1--Project Pile Types and Quantities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Strikes Piles per
Location Item Size and type Qty Duration per pile per pile day Days of activity
(impact) (range)
--------------------------------------------------------------------------------------------------------------------------------------------------------
MD#2................. Dolphin and Fender 48-in (1.22 m) steel 6 Up to 14 hours (840 0-1,500 1 70 days.
Piles. pipe piles. minutes).
Temporary Template Up to 30-in (0.76 m) 8 0-1,500 1
Piles. steel pipe piles.
MD#3................. Dolphin Piles.......... 36-in (0.9 m) steel 3 Up to 14 hours (840 0-1,500 1 95 days.
pipe piles. minutes).
Temporary Template Up to 30-in (0.76 m) 4 0-1,500 1
Piles. steel pipe piles.
MD#4................. Dolphin Piles.......... 36-in (0.9 m) steel 3 Up to 14 hours (840 0-1,500 1
pipe piles. minutes).
[[Page 15960]]
Temporary Template Up to 30-in (0.76 m) 4 0-1,500 1
Piles. steel pipe piles.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Installation of MD#2 would require six 48-inch diameter steel pipe
piles up to 190 ft (57.9 m) in length each. MD#3 and MD#4 each would
require three 36-inch diameter steel pipe piles up to 120 ft (36.6 m)
in length each. These piles would be installed in water depths ranging
between approximately 60 ft (18.3 m) and 160 ft (48.8 m) deep and
driven through approximately 10 ft (3.1 m) of loose, overburden
substrate.
Due to the nature of deep-water pile installation in loose
sediment, various means and methods are required to install a single
pile. Each pile would be installed using various installation methods:
vibratory, impact, and DTH pile driving installation. COK may alternate
between installation methods depending on the conditions encountered.
Only one installation method would occur at a time, but all three
methods may be used in a single day. COK may also be required to splice
on additional lengths of the pile (i.e., weld piles together to make
them longer), with up to three splices expected per pile.
COK would initially vibratory drive all permanent piles to first
refusal, which occurs when they cannot advance the pile tip further
with a vibratory hammer. This would likely happen at bedrock elevation.
COK would seat (or secure) the tip of the pile into bedrock with an
impact hammer, usually to a depth of 1 to 2 ft (0.3 to 0.6 m) into
fractured bedrock. Once the pile has been seated (or secured) into
bedrock with the impact hammer, DTH equipment would be employed to
create rock sockets. Due to limited overburden, all piles require rock
sockets. Sockets up to 20 ft (6.1 m) deep would be hammered through the
pile shaft to the width of the associated pile. COK would then socket
hammer the pile up to 20 ft (6.1 m) into bedrock. The pile would be
drawn into the socket through the hammering action. Finally, a smaller
12-inch diameter DTH device would be used on several piles to drill a
rock anchor hole into bedrock 60 ft (18.3 m) past the pile tip. A 16-
inch diameter casing would be inserted into the pile, and an
approximately 12-inch diameter hole would be drilled up to 60 ft (18.3
m) from the base of the rock socket. Three anchor rods would be
inserted inside the casing, extending from the top of the pile to the
bottom of the 12-inch hole. After component installation, the hammered
12-inch hole and pile casing would be filled with grout.
Temporary template piles would be required to install the permanent
piles at MD#2, #3, and #4 to aid with construction. The temporary
template piles would be removed after the permanent dolphin piles have
been installed. At MD#2, temporary template piles would include up to
eight 30-in (0.8 m) diameter piles or smaller (Table 1). MD#3 and MD#4
would each have up to four piles of up to 30 inches in diameter or
smaller. Between all 3 MDs, there would be 16 temporary template piles.
Once installed, each temporary template pile would measure around 150
ft (46 m) in length and would consist of up to three sections that
would be spliced together as they are installed. Installation methods
for the temporary template piles include vibratory driving piles to
first refusal, and then secured into the bedrock with an impact hammer.
Removal of the temporary template piles would only involve using a
vibratory hammer.
Finally, once all dolphin piles are installed, an off-site
prefabricated steel dolphin cap would be set on top of the piles and
welded to the cap. No in-water work is associated with this feature.
Additionally, one new off-site prefabricated grated catwalk,
approximately 66 ft (20.1 m) in length and 264 ft\2\ (24.5 m\2\), would
be set to provide access to the new MD#2. No in-water work is
associated with this feature either. As such, we do not expect any
effects on marine mammals from installing the dolphin caps and catwalk,
and these components would not be considered further.
The proposed mitigation, monitoring, and reporting measures for
this project are described in detail later in this document (please see
Proposed Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding the status and trends, distribution and habitat preferences,
and behavior and life history of the potentially affected species. NMFS
fully considered all this information, and we refer the reader to these
descriptions in the application instead of reprinting the information.
Additional information regarding population trends and threats may be
found in NMFS' Stock Assessment Reports (SARs; <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>) 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 the Endangered Species Act (ESA) and potential biological
removal (PBR), where known. The MMPA defines PBR 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 (M/SI)
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 comprise a given stock,
or the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Alaska SAR (Young et al. 2024). All values presented in
table 2 below are the most recent available at the time of publication
(including from the final 2023 SAR) 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 15961]]
Table 2--Species With Estimated Take From the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name \1\ Scientific name Stock Strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray whale...................... Eschrichtius robustus.. Eastern North Pacific.. -,-,N 26,960 (0.05, 25,849, 801 131
2016).
Family Balaenopteridae (rorquals):
Fin Whale....................... Balaenoptera physalus.. Northeast Pacific...... E, D, Y UND (UND, UND, 2013) UND 0.6
\5\.
Humpback Whale.................. Megaptera novaeangliae. Hawai[revaps]i \6\..... -,-,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
\7\.
Minke Whale..................... Balaenoptera Alaska................. -,-,N N/A (N/A, N/A, N/A) UND 0
acutorostrata. \8\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer Whale.................... Orcinus orca........... Eastern North Pacific -,-,N 1,920, (N/A, 1,920, 19 1.3
Alaska Resident. 2019) \9\.
Eastern North Pacific -,-,N 302 (N/A, 302, 2018).. 2.2 0.2
Northern Resident.
West Coast Transient... -,-,N 439 (N/A, 349, 2018).. 3.5 0.4
Pacific White-sided Dolphin..... Lagenorhynchus N Pacific.............. -,-,N 26,880 (N/A, N/A, UND 0
obliquidens. 1990).
Family Phocoenidae (porpoises):
Dall's Porpoise................. Phocoenoides dalli..... Alaska................. -,-,N UND (UND, UND, 2015) UND 37
\10\.
Harbor Porpoise................. Phocoena phocoena...... Southern Southeast -,-,Y 890 (0.37, 610, 2019). 6.1 7.4
Alaska Inland Waters
\11\.
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Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
Sea Lion....................... Zalophus californianus. U.S.................... -,-,N 257,606 (N/A, 233,515, 14,011 >321
2014).
Northern Fur Seal............... Callorhinus ursinus.... Eastern Pacific........ -,D,Y 626,618 (0.2, 530,376, 11,403 373
2019) \12\.
Steller Sea Lion................ Eumetopias jubatus..... Eastern................ -,-,N 36,308 (N/A, 36,308, 2,178 93.2
2022) \13\.
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... Clarence Strait........ -,-,N 27,659 (N/A, 24,854, 746 40
2015).
Northern Elephant Seal.......... Mirounga angustirostris CA Breeding............ -,-,N 187,386 (N/A, 85,369, 5,122 13.7
2013).
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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://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>).
\2\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T); MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or 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 <a href="http://www.nmfs.noaa.gov/pr/sars/">www.nmfs.noaa.gov/pr/sars/</a>. CV is the coefficient of variation; Nmin is the minimum estimate
of stock abundance. In some cases, a CV is not applicable. N/A indicates data are unknown. UND (undetermined) PBR indicates data are available to
calculate a PBR level but a determination has been made that calculating a PBR level using those data is inappropriate (see the SAR for details).
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strikes). Annual M/SI often cannot be determined precisely and is sometimes presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ The best available abundance estimate for this stock is not considered representative of the entire stock as surveys were limited to a small portion
of the stock's range. Based upon this estimate and the Nmin, the PBR value is likely negatively biased for the entire stock.
\6\ New SAR in 2022 following North Pacific humpback whale stock structure changes.
\7\ Abundance estimates are based upon data collected more than 8 years ago and, therefore, current estimates are considered unknown.
\8\ Reliable population estimates are not available for this stock. Please see Friday et al. (2013) and Zerbini et al. (2006) for additional information
on numbers of minke whales in Alaska.
\9\ Nest, or the best estimate of abundance, is based upon counts of individuals identified from photo-ID catalogs.
\10\ The best available abundance estimate is likely an underestimate for the entire stock because it is based upon a survey that covered only a small
portion of the stock's range.
\11\ New stock split from Southeast Alaska stock.
\12\ Survey years = Sea Lion Rock--2014; St. Paul and St. George Is--2014, 2016, 2018; Bogoslof Is.--2015, 2019.
\13\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the U.S.
only.
As indicated above, all 13 species with 16 managed stocks in table
2 temporally and spatially co-occur with the activity to the degree
that take is reasonably likely to occur.
For all species except humpback whales, there are no known
biologically important areas (BIA) near the project site that COK's
proposed activity would impact. For humpback whales, the inland waters
of Southeast Alaska are a seasonal feeding BIA from May through
September (Wild et al. 2023). However, due to development and human
presence, Tongass Narrows and Clarence Strait are not essential
portions of this habitat. Tongass Narrows is also a small passageway
representing a tiny portion of the available habitat for humpback
whales.
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 can hear. Not all marine mammal species have equal hearing
capabilities
[[Page 15962]]
(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.). Generalized hearing ranges were chosen based on the
~65 decibel (dB) threshold from composite audiograms, previous analyses
in NMFS (2024), and/or data from Southall et al. (2007) and Southall et
al. (2019). We note that the names of two hearing groups and the
generalized hearing ranges of all marine mammal hearing groups have
been recently updated (NMFS 2024), as reflected below in table 3.
Table 3--Marine Mammal Hearing Groups
[NMFS 2024]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 36 kHz.
whales).
High-frequency (HF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
Very High-frequency (VHF) cetaceans 200 Hz to 165 kHz.
(true porpoises, Kogia, river
dolphins, Cephalorhynchid,
Lagenorhynchus cruciger & L.
australis).
Phocid pinnipeds (PW) (underwater) 40 Hz to 90 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 68 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges may not be as broad. The generalized hearing
range was chosen based on a ~65 dB threshold from a composite
audiogram, previous analysis in NMFS 2018, and/or data from Southall
et al. (2007) and Southall et al. (2019). Additionally, animals can
detect very loud sounds above and below that ``generalized'' hearing
range.
For a review of available information on these groups and
associated frequency ranges, please see NMFS (2024).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section discusses how 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 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.
Acoustic effects on marine mammals during the specified activity
can occur from impact pile driving, vibratory driving and removal, and
DTH. The effects of underwater noise from COK's proposed activity have
the potential to result in Level A and Level B harassment of marine
mammals in the action area.
Description of Sound Sources
The marine soundscape is composed 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 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 are composed of ``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 depends 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 many
varying factors, ambient sound levels can be expected to vary widely
over both coarse and fine spatial and temporal scales. Sound levels at
a given frequency and location can vary by 10-20 dB from day to day
(Richardson et al. 1995). The result is that, depending on the source
type and its intensity, sound from the specified activity may be a
negligible addition to the local environment or form a distinctive
signal that may affect marine mammals.
In-water construction activities associated with the project would
include vibratory pile driving and pile removal, impact pile driving,
and DTH pile 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, and 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 (American National Standards Institute (ANSI) 1986;
National Institute for Occupational Safety and Health (NIOSH) 1998;
ANSI 2005; NMFS 2024). 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 high
peak sound pressure with rapid rise/decay time that impulsive sounds do
(ANSI 1995; NIOSH 1998; NMFS 2024). The distinction between these two
sound types is important because they have differing potential to cause
physical effects, particularly regarding hearing (e.g., Ward 1997 in
Southall et al. 2007).
Three types of hammers would be used in this project: impact,
vibratory, and DTH. Impact hammers repeatedly drop a heavy piston onto
a pile to drive the pile into the substrate. The 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
hammer's weight 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
[[Page 15963]]
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 more time (Nedwell and Edwards 2002; Carlson
et al. 2005).
A DTH hammer is used to place hollow steel piles or casings by
drilling. A DTH hammer is a drill bit that drills through the bedrock
using a pulse mechanism that functions at the bottom of the hole. This
pulsing bit breaks up the rock to allow for the removal of debris and
insertion of the pile. The head extends so that the drilling takes
place below the pile. The sounds produced by DTH hammers were
previously thought to be continuous. However, recent sound source
verification (SSV) monitoring has shown that a DTH hammer can create an
impulsive sound (Denes et al. 2019). Since sound from DTH activities
has both impulsive and continuous components, NMFS characterizes sound
from DTH pile installation as being impulsive when evaluating potential
Level A harassment (i.e., injury) impacts and as being non-impulsive
when assessing potential Level B harassment (i.e., behavior) effects.
COK's proposed activity could impact marine mammals through non-
acoustic and acoustic stressors. Potential non-acoustic stressors could
result from the physical presence of the equipment, vessels, and
personnel; however, any impacts on marine mammals are expected to be
primarily acoustic. Acoustic stressors include the effects of heavy
equipment operation during pile installation and removal.
Acoustic Impacts
Introducing anthropogenic noise into the aquatic environment from
pile driving and removal is the primary way COK's specified activity
may harass marine mammals. In general, animals exposed to natural or
anthropogenic sound may experience physical and psychological effects,
ranging in magnitude from none to severe (Southall et al. 2007). In
general, exposure to pile driving and removal noise can result in
auditory threshold shifts and behavioral disturbance (e.g., avoidance,
temporary cessation of foraging and vocalizing, and changes in dive
behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses, such as increased 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 and removal 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. 2003; 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 2024). The amount of
threshold shift is customarily expressed in dB. A TS can be permanent
or temporary. As described in NMFS (2024), there are numerous factors
to consider when examining the consequences of TS, including, but not
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), the likelihood an individual would be exposed for a long
enough duration or to a high enough level to induce a TS, the magnitude
of the TS, time to recovery (seconds to minutes or hours to days), the
frequency range of the exposure (i.e., spectral content), the hearing
and vocalization frequency range of the exposed species relative to the
signal's frequency spectrum (i.e., how an animal uses sound within the
frequency band of the signal; e.g., Kastelein et al. 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2024). Available data from
humans and other terrestrial mammals indicate that a 40 dB threshold
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960;
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al.
2008). PTS levels for marine mammals are estimates. Other than the
exception of a single study unintentionally inducing PTS in a harbor
seal (Kastak et al. 2008), there is no empirical data measuring PTS in
marine mammals, mainly because, for various ethical reasons,
experiments involving anthropogenic noise exposure at levels inducing
PTS are not typically pursued or authorized (NMFS 2024).
Temporary Threshold Shift (TTS)--This is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS 2024). Based on data from cetacean TTS
measurements (see Southall et al. 2007), a TTS of 6 dB is considered
the minimum threshold shift larger than any day-to-day or session-to-
session variation in a subject's normal hearing ability (Schlundt et
al. 2000; Finneran et al. 2000, 2002). As described in Finneran (2015),
marine mammal studies have shown the amount of TTS increases with
cumulative sound exposure level (SELcum) in an accelerating fashion: At
low exposures with lower SELcum, the amount of TTS is typically small
and the growth curves have shallow slopes. At exposures with higher
SELcum, the growth curves become steeper and approach linear
relationships with the noise sound exposure level (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
not as many competing sounds are present. Alternatively, a larger
amount and longer duration of TTS sustained 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, humans, and
other taxa (Southall et al. 2007). Therefore, we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena
asiaeorientalis)) and five species of pinnipeds exposed to a limited
number of sound sources (i.e., primarily tones and octave-band noise)
in laboratory settings (Finneran 2015). TTS was not observed in trained
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to
impulsive noise at levels matching previous predictions of TTS onset
(Reichmuth et
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al. 2016). In general, harbor seals and harbor porpoises have a lower
TTS onset than other measured pinniped or cetacean species (Finneran
2015). Additionally, the existing marine mammal TTS data come from a
limited number of individuals within these species. No data on noise-
induced hearing loss for mysticetes is available. For summaries of data
on TTS in marine mammals or further discussion of TTS onset thresholds,
please see Southall et al. (2007), Finneran and Jenkins (2012),
Finneran (2015), and table 5 in NMFS (2024).
Installing piles for the project requires a combination of impact
pile driving, vibratory pile driving, and DTH hammering. These
activities would not occur simultaneously for the project, and there
would likely be pauses in activities that produce the sound each day.
Given these pauses and the fact that many marine mammals are likely
moving through the action area and not remaining for extended periods,
the potential for TS declines.
Behavioral Harassment--Exposure to noise from DTH and pile driving
and removal can also potentially disturb marine mammals behaviorally.
Available studies show wide variation in response to underwater sound;
therefore, it is difficult to predict precisely 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; and National Research
Council (NRC) 2005).
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); and avoidance of areas where sound sources are located.
Pinnipeds may increase their haul-out time to avoid in-water
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are
highly variable and context-specific. Any reactions depend on numerous
intrinsic and extrinsic factors (e.g., species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
and time of day), as well as the interplay between factors (e.g.,
Richardson et al. 1995; Wartzok et al. 2003; Southall et al. 2007;
Weilgart 2007; Archer et al. 2010). Behavioral reactions can vary among
individuals and within an individual, depending on previous experience
with a sound source, context, and numerous other factors (Ellison et
al. 2012). They 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 cetaceans and generally seem less
responsive to exposure to industrial sound than most cetaceans. Please
see Appendices B and C of Southall et al. (2007) for a review of
studies involving marine mammal behavioral responses to sound.
The 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). Whether foraging disruptions are more likely to incur
fitness consequences may be informed by 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.
In 2016, the Alaska Department of Transportation and Public
Facilities (ADOT&PF) documented observations of marine mammals during
construction activities (i.e., pile driving and DTH drilling) at the
Kodiak Ferry Dock (see 80 FR 60636, October 7, 2015). In that project's
marine mammal monitoring report (Alaska Biological Research, Inc. (ABR)
2016), 1,281 Steller sea lions were observed within the Level B
disturbance zone during pile driving or drilling (i.e., documented as
Level B harassment take). Of these, 19 individuals demonstrated alert
behavior, 7 fled, and 19 swam away from the project site. All other
animals (98 percent) were engaged in milling, foraging, or fighting
activities and did not change their behavior. In addition, two sea
lions approached within 65 ft (20 m) of active vibratory pile-driving
activities, and three harbor seals were observed within the disturbance
zone during pile-driving activities; none displayed disturbance
behaviors. Fifteen killer whales and three harbor porpoises were also
observed within the Level B harassment zone during pile driving. The
killer whales were traveling or milling while all harbor porpoises were
traveling. No signs of disturbance were noted for either of these
species. Given the similarities in species, activities, and habitat, we
expect similar behavioral responses of marine mammals to COK's
specified activity. That is, disturbance, if any, is likely to be
temporary and localized (e.g., small area movements).
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg
2000). In many cases, an animal's first and sometimes most economical
(in terms of energetic costs) response is behavioral avoidance of the
potential stressor. Autonomic nervous system responses to stress
typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not significantly affect an animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. All stress-related neuroendocrine functions--
including immune competence, reproduction, metabolism, and behavior--
are regulated by pituitary hormones. Stress-induced changes in the
secretion of pituitary hormones have been implicated in failed
reproduction, altered metabolism, reduced immune competence, and
behavioral disturbance (e.g., Moberg 1987; Blecha 2000). Increases in
the circulation of glucocorticoids are also equated with stress (Romano
et al. 2004).
The primary distinction between stress (which is adaptive and does
not usually place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can quickly replenish once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other
[[Page 15965]]
functions. This state of distress would last until the animal
replenishes its energetic reserves sufficient to restore normal
function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al. 1996; Hood et al. 1998; Jessop et al. 2003;
Krausman et al. 2004; Lankford et al. 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker 2000; Romano
et al. 2002b) and, more rarely, studied in wild populations (e.g.,
Romano et al. 2002a). For example, Rolland et al. (2012) found that
noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals would experience physiological stress responses upon exposure
to acoustic stressors and that it is possible that some of these would
be classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC 2003); however,
distress is an unlikely result of this project based on observations of
marine mammals during previous similar projects in the area.
Masking--Sound can disrupt behavior through masking or interfering
with an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al. 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and similar or higher intensity. Masking may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
and precipitation) or anthropogenic (e.g., pile driving, shipping,
sonar, and seismic exploration) in origin. The ability of a noise
source to mask biologically important sounds depends on the
characteristics of both the noise source and the signal of interest
(e.g., signal-to-noise ratio, temporal variability, direction) in
relation to each other and to an animal's hearing abilities (e.g.,
sensitivity, frequency range, critical ratios, frequency
discrimination, directional discrimination, age, or TTS hearing loss),
and existing ambient noise and propagation conditions. The masking of
natural sounds can result when human activities produce high background
sound levels at frequencies important to marine mammals. Conversely, if
the background level of underwater sound is high (e.g., on a day with
strong wind and high waves), an anthropogenic sound source would not be
detectable as far away as possible under quieter conditions and would
be masked. The Ketchikan area contains active commercial shipping,
cruise ships, ferry operations, and numerous recreational and other
commercial vessels; therefore, background sound levels in the region
are already elevated.
Airborne Acoustic Effects--Pinnipeds near the project site could be
exposed to airborne sounds associated with DTH and pile driving and
removal. Depending on their distance from pile-driving activities,
these sounds can cause behavioral harassment. 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 swimming or hauled-
out pinnipeds near the project site, within the range of noise levels
above 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 about underwater sound. For instance, anthropogenic
sound could cause hauled-out pinnipeds to exhibit changes in their
normal behavior, such as reduced vocalizations, or cause them to
abandon the area and move further from the source temporarily. However,
these animals would previously have been ``taken'' because of exposure
to underwater sound above the behavioral harassment thresholds, which
are generally larger than those associated with airborne sound.
Additionally, there are no haul outs near the project site. Thus, the
behavioral harassment of these animals is already accounted for in
underwater 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 further discussed.
Marine Mammal Habitat Effects
COK's construction activities could have localized, temporary
impacts on marine mammal habitat and their prey by increasing in-water
sound pressure levels and slightly decreasing water quality. Increased
noise levels may affect the acoustic habitat (see masking discussion
above) and adversely affect marine mammal prey near the project area
(see discussion below). During DTH, impact, and vibratory pile driving
or removal, elevated underwater noise levels would ensonify the project
area where fish and mammals occur and could affect foraging success.
Additionally, marine mammals may avoid the area during construction.
However, displacement due to noise is expected to be temporary and not
result in long-term effects on the individuals or populations.
In-Water Construction Effects on Potential Foraging Habitat
As previously mentioned, the project area does not contain habitat
of known importance other than being designated as a feeding BIA for
humpback whales between May and September. While the entirety of
southeast Alaska is considered a feeding BIA for humpback whales,
Tongass Narrows represents only a tiny segment. Additionally, the
project area is highly influenced by anthropogenic activities.
The total seafloor area affected by pile installation and removal
is small compared to the vast foraging area available to marine mammals
in the area. At best, the impact area provides marginal foraging
habitat for marine mammals and fish. Furthermore, pile driving and
removal at the project site would not obstruct the movement or
migration of marine mammals.
A temporary and localized increase in turbidity near the seafloor
would occur in the immediate area surrounding the area where piles are
installed or removed. In general, turbidity associated with pile
installation is localized to about a 25-ft (7.6-m) radius around the
pile (Everitt et al. 1980). The sediments of the project site would
settle out rapidly when disturbed. Cetaceans are not expected to be
close enough to the pile-driving areas to experience the effects of
turbidity, and any pinnipeds could avoid localized turbid areas.
Depending on the tidal stage, local strong currents are anticipated to
disburse any additional suspended sediments produced by project
activities at moderate to rapid rates. Therefore, we expect the impact
from increased turbidity levels to be discountable to marine mammals
and do not discuss it further.
The potential for prey (i.e., fish) to temporarily avoid the
immediate area is also possible. The duration of fish avoidance in this
area after pile driving stops is unknown, but a rapid return to normal
recruitment, distribution, and behavior is anticipated. Any behavioral
avoidance by fish in disturbed areas would still leave significantly
large
[[Page 15966]]
areas of fish and marine mammal foraging habitats nearby.
In-Water Construction Effects on Potential Prey
Sound may affect marine mammals by impacting the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, and zooplankton). Marine mammal prey varies by
species, season, and location. Here, we describe studies regarding the
effects of noise on known marine mammal prey.
Fish use the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick and Mann 1999; Fay 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fish hear sounds using pressure and particle
motion sensitivity capabilities and detect the motion of surrounding
water (Fay et al. 2008). The potential effects of noise on fish depend
on the overlapping frequency range, distance from the sound source,
water depth of exposure, and species-specific hearing sensitivity,
anatomy, and physiology. Key impacts on fish may include behavioral
responses, hearing damage, barotrauma (pressure-related injuries), and
mortality.
Fish react to sounds that are powerful and/or intermittent low-
frequency sounds, and behavioral responses such as flight or avoidance
are the most likely effects. Short-duration, sharp sounds can cause
overt or subtle changes in fish behavior and local distribution. The
reaction of fish to noise depends on the physiological state of the
fish, past exposures, motivation (e.g., feeding, spawning, migration),
and other environmental factors. Hastings and Popper (2005) identified
several studies that suggest fish may relocate to avoid certain areas
of sound energy. Additional studies have documented the effects of pile
driving on fish, although several are based on studies supporting
large, multiyear bridge construction projects (e.g., Scholik and Yan
2001, 2002; Popper and Hastings 2009). Several studies have
demonstrated that impulse sounds might affect the distribution and
behavior of some fish, potentially impacting foraging opportunities or
increasing energetic costs (e.g., Fewtrell and McCauley 2012; Pearson
et al. 1992; Skalski et al. 1992; Santulli et al. 1999; Paxton et al.
2017). However, some studies have shown no or slight reaction to
impulse sounds (e.g., Pena et al. 2013; Wardle et al. 2001; Jorgenson
and Gyselman 2009; Popper et al. 2005).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate, and loss of auditory function is likely
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a 4-6 dB TTS was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe, can cause
death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al. 2012b; Casper et al. 2013).
The most likely impact on fish from DTH and pile driving and
removal activities at the project area would be temporary behavioral
avoidance of the area. The duration of fish avoidance in this area
after pile driving stops is unknown, but a rapid return to regular
recruitment, distribution, and behavior is anticipated.
There are times of known seasonal marine mammal foraging in Tongass
Narrows around fish processing/hatchery infrastructure (PND 2024) or
when fish are congregating, but the affected areas of Tongass Narrows
are a small portion of the total foraging habitat available in the
region. In general, effects on marine mammal prey species are expected
to be minor and temporary due to the short timeframe of the project and
the small project footprint.
Increased turbidity from construction activities can adversely
affect forage fish and juvenile salmonid out-migratory routes in the
project area. Both herring and salmon form a significant prey base for
Steller sea lions, whereas herring is the primary prey species of
humpback whales; both herring and salmon are components of the diet of
many other marine mammal species that occur in the project area.
Increased turbidity is expected to happen near construction activities.
However, suspended sediments and particulates are expected to dissipate
quickly within a single tidal cycle. Given the limited area affected
and high tidal dilution rates, any effects on forage fish and salmon
are expected to be minor or negligible. In addition, best management
practices would be in effect, limiting the extent of turbidity to the
immediate project area. Finally, exposure to turbid waters from
construction activities is not expected to differ from the current
exposure; fish and marine mammals in the Tongass Narrows region are
routinely exposed to substantial levels of suspended sediment from
glacial sources.
In summary, given the temporary nature of the construction project
and relatively small areas being affected, the DTH and pile driving and
removal activities associated with the proposed action are not likely
to have a permanent, adverse effect on any fish habitat or populations
of fish species. Any behavioral avoidance by fish in disturbed areas
would still leave significantly large areas of fish and marine mammal
foraging habitats nearby. Thus, we conclude that the 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 on marine mammal habitats are not expected to result in
significant or long-term consequences for individual marine mammals or
to contribute to the adverse effects on their populations.
Estimated Take of Marine Mammals
This section estimates the number of incidental takes proposed for
authorization through the IHA. This information will inform NMFS'
consideration of ``small numbers,'' negligible impact determinations,
and impacts on subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except for 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 disrupting behavioral patterns, including, but not limited
to, migration, breathing, nursing, breeding, feeding, or sheltering
(Level B harassment).
Authorized takes would predominantly be by Level B harassment, as
using acoustic sources (i.e., vibratory or impact pile driving and DTH)
can potentially disrupt behavioral patterns for individual marine
mammals. There is also some potential for auditory injury (AUD INJ)
(Level A harassment) to result for 7 species (8 stocks). However, 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
[[Page 15967]]
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 criteria above which NMFS believes the best
available science indicates that marine mammals would likely be
behaviorally harassed or incur some degree of AUD INJ; (2) the area or
volume of water that would 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. 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 in more detail and present the proposed take
estimates.
Acoustic Criteria
NMFS recommends using acoustic criteria to identify the received
level of underwater sound above which exposed marine mammals would
reasonably expect to be behaviorally harassed (equated to Level B
harassment) or incur AUD INJ of some degree (equated to Level A
harassment). We note that the criteria for AUD INJ and the names of two
hearing groups have been recently updated (NMFS 2024), as reflected
below in the Level A Harassment section.
Level B Harassment--Though significantly driven by the 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
complex to predict (e.g., Southall et al. 2007, 2021; Ellison et al.
2012). Based on what the available science indicates and the practical
need to use a threshold based on a predictable and measurable metric
for most activities, NMFS typically uses a generalized acoustic
threshold based on the 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. In most cases, the likelihood of
TTS occurring at distances from the source is less than at which
behavioral harassment is probable. TTS of a sufficient degree can
manifest as behavioral harassment, as reduced hearing sensitivity and
the potential reduced opportunities to detect essential signals
(conspecific communication, predators, and prey) may result in changes
in behavior patterns that would not otherwise occur.
COK's proposed activity includes continuous (vibratory pile
driving, DTH drilling) and impulsive (impact pile driving, DTH
hammering) sources; therefore, the RMS SPL thresholds of 120 and 160 dB
re 1 [mu]Pa are applicable.
Level A harassment--NMFS' Updated Technical Guidance for Assessing
the Effects of Anthropogenic Sound on Marine Mammal Hearing (Version
3.0) (NMFS 2024) identifies dual criteria to assess AUD INJ (Level A
harassment) to five different underwater marine mammal groups (based on
hearing sensitivity) as a result of exposure to noise from two
different types of sources (impulsive or non-impulsive). COK's proposed
activity includes using impulsive (impact pile driving, DTH pile
installation) and non-impulsive (vibratory pile driving/removal, DTH
pile installation) sources.
The 2024 Updated Technical Guidance criteria include updated
thresholds and weighting functions for each hearing group, provided in
table 4 below. The references, analysis, and methodology used to
develop the criteria are described in NMFS' 2024 Updated Technical
Guidance, which may be accessed at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools</a>.
Table 4--Thresholds Identifying the Onset of Auditory Injury
----------------------------------------------------------------------------------------------------------------
AUD INJ onset acoustic thresholds * (received level)
Hearing group -------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.......... Cell 1: Lpk,flat: 222 dB; Cell 2: LE,LF,24h: 197 dB.
LE,LF,24h: 183 dB.
High-Frequency (HF) Cetaceans......... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,HF,24h: 201 dB.
LE,HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,VHF,24h: 181 dB.
LE,VHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater).... Cell 7: Lpk,flat: 223 dB; Cell 8: LE,PW,24h: 195 dB.
LE,PW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater)... Cell 9: Lpk,flat: 230 dB; Cell 10: LE,OW,24h: 199 dB.
LE,OW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for
calculating AUD INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure
level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-
impulsive sources.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1 [micro]Pa\2\s. In this table, the criteria are abbreviated to
be more reflective of the International Organization for Standardization (ISO) standards (ISO 2017; ISO 2020).
The subscript ``flat'' is included to indicate peak sound pressure is flat-weighted or unweighted within the
underwater generalized hearing range of marine mammals (i.e., 7 Hz to 165 kHz). The subscript associated with
cumulative sound exposure level criteria indicates the designated marine mammal auditory weighting function
(LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours.
The weighted cumulative sound exposure level criteria could be exceeded in many 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 criteria will be exceeded.
[[Page 15968]]
Ensonified Area
Here, we describe the operational and environmental parameters of
the activity 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., vibratory pile driving,
vibratory pile removal, impact pile driving, and DTH pile
installation).
Level B Harassment Zones
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, 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; for practical spreading equals 15
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 depends on various factors, most
notably the water bathymetry and the 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 occurs. 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, 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 and impact pile installation of steel pipe piles, vibratory
removal of steel pipe piles, and DTH. Source levels for each pile size
and driving method are presented in table 5.
Table 5--Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
Sound source level at 10 meters
---------------------------------------------------------
Method and pile size dB RMS re dB peak re dB SEL re Literature source
1[micro]Pa 1[micro]Pa 1[micro]Pa\2\sec
----------------------------------------------------------------------------------------------------------------
Vibratory Hammer
----------------------------------------------------------------------------------------------------------------
30-inch.......................... 166 ................. ................. Denes et al. 2016
36-inch.......................... 166 ................. ................. Austin et al. 2016
48-inch.......................... 171 ................. ................. Austin et al. 2016
----------------------------------------------------------------------------------------------------------------
Impact Hammer
----------------------------------------------------------------------------------------------------------------
30-inch.......................... 190 210 177 Denes et al. 2016,
Caltrans 2015
36-inch.......................... 193 210 183 Austin et al. 2016,
Caltrans 2015
48-inch.......................... 192 213 179 Caltrans 2020
----------------------------------------------------------------------------------------------------------------
DTH Pile Installation
----------------------------------------------------------------------------------------------------------------
DTH Sockets (30-inch)............ 174 194 164 Reyff & Heyvaert
(2019), Reyff
(2020), Denes et
al. (2016), Denes
et al. (2019)
DTH Sockets (36-inch)............ 174 194 164 Reyff & Heyvaert
(2019), Reyff
(2020), Denes et
al. (2016), Denes
et al. (2019)
DTH Sockets (48-inch)............ 178 ................. 168 Extrapolated from
DTH SSV studies
listed below; Denes
et al. (2016)
DTH Anchors (12-inch)............ 167 146 172 Guan and Miner
(2020)
----------------------------------------------------------------------------------------------------------------
SS SEL = single strike sound exposure level; dB peak = peak sound level; rms = root mean square.
Using the practical spreading model, NMFS determined underwater
noise would fall below the behavioral effects threshold of 120 dB rms
for marine mammals at a maximum radial distance of 11,659.1 m for
vibratory pile driving of 30- and 36-inch diameter piles, and 25,118.9
m for vibratory pile driving of 48-inch diameter piles. Other
activities, including rock anchoring and impact pile driving, have
smaller Level B harassment zones. All Level B harassment isopleths are
reported in table 7 below. It should be noted that based on the
geography of Tongass Narrows and the surrounding islands, the sound
would not reach the entire distance of the Level B harassment
isopleths. Land masses would truncate the largest Level B Harassment
isopleth at approximately 12,500 m to the southeast and approximately
3,590 m northwest of the project area. Constraining land masses include
Revillagigedo Island, Gravina Island, Pennock Island, and Spire Island.
Level A Harassment Zones
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional
[[Page 15969]]
User Spreadsheet tool to accompany the 2024 Updated Technical Guidance
that can predict an isopleth distance 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
would typically be overestimates of some degree, which may result in an
overestimation 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, the optional User Spreadsheet tool predicts the distance at
which, if a marine mammal remained at that distance for the duration of
the activity, it would be expected to incur AUD INJ. Inputs used in the
optional User Spreadsheet tool (table 6), the resulting estimated
isopleths, and the calculated Level A and Level B harassment isopleths
(table 7), are reported below.
Table 6--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile driving Impact pile driving DTH Sockets DTH Anchor
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Equipment type 30-, 36-in steel 48-in steel 30-in steel 36-in steel 48-in steel 12-in rock
piles piles piles piles piles 30-in 36-in 48-in anchor
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used.......... A.1) Vibratory Pile Driving
E.1) Impact Pile Driving
E.2) DTH Systems.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (dB re: 1 166 RMS......... 171 RMS......... 177 SEL/190 RMS. 183 SEL/193 RMS. 180 SEL/192 RMS. 164 SEL......... 164 SEL......... 168 SEL......... 146 SEL.
[micro]Pa).
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Weighting Factor Adjustment 2.5
(kHz).
2
2 2.5.............
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Activity Duration within 24 Up to 8 hrs OR Up to 14 hrs
hours \1\.
10 minutes/20 minutes/30 minutes Up to 4 hrs OR Up to 3 hrs OR Up to 4 hrs OR Up to 4 hrs.....
Up to 8 hrs. Up to 4 hrs. Up to 8 hrs.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Strike per second.............
5.8.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Number of strikes per pile....
Up to 500 strikes/501-1,000 strikes/1,001-1,500
strikes.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Number of piles per day....... 1
1
1.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Propagation (xLogR)........... 15
15
15.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Distance of sound pressure 10
level measurement (m).
10
10.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The application states that in order to calculate Level A isopleths, a maximum duration of 14 hours of noise-generating activity is used. Actual daily durations would not exceed 12 hours,
and may be less than 12 hours.
Table 7--Calculated Level A Harassment and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
AUD INJ onset isopleth (m)
-----------------------------------------------------------------
Cetaceans Pinnipeds Level B
Source Daily duration \1\ ----------------------------------------------------------------- harassment
Low- High- Very high- isopleth (m)
frequency frequency frequency Phocid Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
30- and 36-inch Vibratory (Installation 8 hours........................ 79.5 30.5 64.9 102.3 34.4 11,659.1
or Removal).
14 hours....................... 115.4 44.3 94.3 148.6 50.0 ............
48-inch Vibratory....................... 8 hours........................ 171.2 65.8 139.9 220.4 74.2 25,118.9
14 hours....................... 248.7 95.5 203.1 320.1 107.7 ............
30-inch Impact.......................... 10 minutes..................... 249.5 31.8 386.2 221.7 82.6 1,000.0
20 minutes..................... 396.1 50.5 613.0 351.9 131.2 ............
30 minutes..................... 519.1 66.2 803.3 461.1 171.9 ............
36-inch Impact.......................... 10 minutes..................... 626.8 80.0 970.0 556.8 207.6 1,584.9
20 minutes..................... 995.0 127.0 1,539.8 883.9 329.5 ............
30 minutes..................... 1,303.8 166.4 2,017.7 1,158.3 431.8 ............
48-inch Impact.......................... 10 minutes..................... 395.5 50.5 612.0 351.3 131.0 1,359.4
20 minutes..................... 627.8 80.1 971.5 557.7 207.9 ............
30 minutes..................... 822.7 105.0 1,273.1 730.8 272.4 ............
30- and 36-inch Down-the-Hole........... 4 hours........................ 1,028.9 131.3 1,592.1 914.0 340.7 39,810.7
8 hours........................ 1,633.2 208.4 2,527.4 1,450.9 540.8 ............
48-inch Down-the-Hole................... 4 hours........................ 1,901.2 242.6 2,942.0 1,688.9 629.6 73,564.2
8 hours........................ 3,017.9 385.1 4,670.2 2,681.0 999.4 ............
12-inch Rock Anchor..................... Up to 4 hours.................. 64.3 9.8 179.5 60.9 27.9 13,593.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ In order to calculate Level A isopleths, a maximum duration of 14 hours of noise-generating activity was used. Actual daily durations would not
exceed 12 hours, and may be less than 12 hours.
[[Page 15970]]
Marine Mammal Occurrence
This section provides information about the marine mammals that are
anticipated or could potentially occur in the action area during the
project construction. For ease, this information has been summarized in
table 8 and includes the frequency, average group size, expected
occurrence, and source reference of each marine mammal species. It is
based on historical data of occurrence, seasonality, and group size in
the Tongass Narrows and around the Ketchikan area specifically, where
possible. This information is based on consultation with previous IHAs,
monitoring reports, information from the application, and references
cited. For more detailed information, 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. This occurrence
information then informs the take calculation in the next section
(please see Take Estimation and table 9).
To accurately describe species occurrence near the action area,
marine mammals were described as either common (confirmed and regular/
daily sightings), frequent (confirmed and with some consistency during
most monitoring efforts in the project vicinity; assumes weekly
occurrence), infrequent (confirmed but irregular sightings during most
monitoring efforts in the project vicinity; assumes monthly or every
other month occurrence), or rare (a few sightings annually).
Table 8--Estimated Occurrence of Group Sightings of Marine Mammal Species
----------------------------------------------------------------------------------------------------------------
Expected
Species Frequency Average group size occurrence Reference
----------------------------------------------------------------------------------------------------------------
Humpback whale.................. Frequent.......... 2................. 2x/week........... Dalheim et al.
(2009), PND
(2024).
Minke whale..................... Rare.............. 1................. Annually.......... Dalheim et al.
(2009), PND
(2024).
Fin whale....................... Rare.............. 2................. 2x/year........... Crance et al.
(2023), PND
(2024),
88 FR 46746.
Gray whale...................... Infrequent........ 1................. Monthly........... Dalheim et al.
(2009), PND
(2024).
Killer whale.................... Infrequent........ 10................ Monthly........... Dalheim et al.
(2009), PND 2024.
Pacific white-sided dolphin..... Frequent.......... 20................ Weekly............ Dalheim et al.
(2009), PND
(2024), 84 FR
36891.
Harbor porpoise................. Infrequent........ 5................. 2x/month.......... PND (2024),
Sitkiewicz
(2020).
Dall's porpoise................. Infrequent........ 15................ Monthly........... Dalheim et al.
(2009), PND
(2024), 84 FR
36891.
Steller sea lion................ Common............ 10 (Sept-Feb), 20 Daily............. PND (2024).
(Mar-Aug).
California sea lion............. Rare.............. 1................. Every 2 months.... Maniscalco et al.
(2004), PND
(2024).
Northern fur seal............... Rare.............. 2................. Annually.......... PND (2024).
Harbor seal..................... Common............ 3................. 3x/daily.......... PND (2024),
Sitkiewicz
(2020).
Northern Elephant Seal.......... Frequent.......... 1................. Weekly............ PND (2024).
----------------------------------------------------------------------------------------------------------------
Take Estimation
Here, we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and is proposed for authorization. Once again, NMFS
carefully considered all information and analyses the applicant
presented as well as information in recent IHAs and monitoring reports
for projects in the nearby area. Since reliable densities are not
available, the applicant requests take based on the maximum number of
animals that may occur in the area in a specified measure of time
multiplied by the total duration of the activity.
The number of marine mammals that may be exposed to harassment
thresholds was calculated by estimating the likelihood of a marine
mammal being present within a harassment zone during the associated
activities (table 9). That is, group size was multiplied by the
frequency (e.g., 3x/day for harbor seals, 2x/month for harbor
porpoises, 0.5x/month for California sea lions) multiplied by the
project duration, either 166 days, or 23.7 weeks, or 5.5 months.
Calculations were then rounded up to a whole number.
The calculations were modified for humpback whales and Steller sea
lions. For humpback whales, group size (2) is multiplied by frequency
(2x/week, which is 23.7 weeks x 2) multiplied by 0.976 percent, which
is the apportionment of whales for the Hawai'i stock (Lizewski et al.
2021). This equates to 93 total proposed takes for the Hawai[revaps]i
stock of humpback whales. For the Mexico-North Pacific stock, 0.024
percent of whales are apportioned (Lizewski et al. 2021), which equates
to 3 total proposed takes. For Steller sea lions, 0.75 percent of
estimated takes are apportioned to the group size of 10 individuals
that are anticipated to occur daily from September to February, and
0.25 percent of estimated takes are apportioned to the group size of 20
individuals that are anticipated to occur daily from March to August.
This equates to 1,810 total proposed takes of the Eastern U.S. stock of
Steller sea lions. All numbers were then rounded up to the nearest
whole number.
As table 9 shows, we calculated Level B takes for all 13 species
(16 stocks). However, several species were calculated as having just
one Level A take. Therefore, we considered the size of the animal, the
frequency of the animal in the project area, as well as the shutdown
zone sizes for each species. No Level A takes are proposed for
authorization for minke, fin, gray, and killer whales, and northern fur
seal and California sea lion. The proposed Level A takes for two other
species were rounded up based on average group size. Since Pacific
white-sided dolphins have an average group size of 20 animals, we
increased the proposed Level A takes for Pacific white-sided dolphins
to 20. Similarly for Dall's porpoise, because the average group size is
15, we increased the proposed Level A takes to 15.
Table 9 summarizes the proposed authorized take by Level A and
Level B harassment, the total proposed take, and the proposed take as a
percentage of stock abundance.
[[Page 15971]]
Table 9--Proposed Authorized Take by Level A and Level B Harassment and as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Authorized take
---------------------------------------
Common name Stock Stock abundance \1\ Total Percent of
Level A Level B proposed stock
take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale........................... Hawai[revaps]i.............. 11,278..................... 10 \2\ 83 93 0.8
Mexico-North Pacific........ \3\ N/A.................... 1 2 3 N/A
Minke whale.............................. Alaska...................... N/A........................ 0 1 1 N/A
Fin whale................................ Northeast Pacific........... \4\ UND.................... 0 3 3 N/A
Gray whale............................... Eastern North Pacific....... 26,960..................... 0 5 5 0.02
Killer Whale............................. Eastern North Pacific Alaska 1,920...................... 0 55 55 2.9
Resident.
Eastern North Pacific 302........................ 18.2
Northern Resident.
West Coast Transient........ 349 15.8
Pacific white-sided dolphin.............. North Pacific............... 26,880..................... 20 473 493 1.8
Harbor porpoise.......................... Southern Southeast Alaska 890........................ 10 46 56 6.3
Inland Waters.
Dall's porpoise.......................... Alaska...................... UND........................ 15 69 84 N/A
Steller sea lion......................... Eastern U.S................. 36,308..................... 30 1,780 1,810 5.0
California sea lion...................... U.S......................... 257,606.................... 0 2 2 0.0008
Northern fur seal........................ Eastern Pacific............. 626,618.................... 0 1 1 0.0002
Harbor seal.............................. Clarence Strait............. 27,659..................... 129 1,365 1,494 5.4
Northern elephant seal................... California.................. 187,386.................... 3 21 24 .01
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Stock size is Nbest (i.e., the statistical estimate of the overall population size) according to NMFS 2023 Final Stock Assessment Reports.
\2\ For MMPA take apportionment and ESA section 7 consultation purposes, 2.4 percent are designated to the Mexico-North Pacific stock, and the remaining
are designated to the Hawai'i stock.
\3\ N/A indicates data are not available/unknown.
\4\ UND (undetermined) indicates data are unavailable to calculate stock abundance data (see the SAR for details).
Proposed Mitigation
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. NMFS pays particular attention to
rookeries, mating grounds, and areas of similar significance, as well
as the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) How and the degree to which the successful implementation of
the measure(s) is expected to reduce impacts on marine mammals, marine
mammal species or stocks, and their habitat. This considers the nature
of the potential adverse effects being mitigated (likelihood, scope,
range). It further considers the likelihood that the measure would be
effective if implemented (probability of accomplishing the mitigating
result if implemented as planned), the likelihood of effective
implementation (probability of implementation as planned), and
(2) The practicability of the measures for applicant
implementation, which may consider cost and impact on operations.
In addition to the measures described later in the Proposed
Monitoring and Reporting section and all mitigation measures described
in COK's Marine Mammal Monitoring Plan, the following mitigation
measures would also apply to COK's in-water construction activities.
<bullet> Implementation/Coordination--Qualified, trained Protected
Species Observers (PSOs) would implement mitigation measures. PSOs
would be located on-site before, during, and after permitted activities
to monitor protected species within (and approaching) mitigation zones.
PSOs would be in constant contact with the construction personnel to
implement appropriate mitigation measures.
An employee of the construction contractor would be identified as
the monitoring coordinator for PSOs at the start of each construction
day. PSOs would report directly to the monitoring coordinator when a
shutdown is deemed necessary. Briefings must be conducted between
construction supervisors and crews and the marine mammal monitoring
team before the start of all pile driving activity and when new
personnel join the work to explain responsibilities, communication
procedures, marine mammal monitoring protocol, and operational
procedures.
<bullet> PSOs--COK must employ PSOs who would monitor the project
area to the maximum extent possible based on the required number of
PSOs, required monitoring locations, and environmental conditions. The
number, placement, and qualifications of PSOs during all pile driving
and removal activities (described in detail in the Monitoring and
Reporting section) would ensure that the entire shutdown zone is
visible during pile installation. Should environmental conditions
deteriorate such that marine mammals within the entire shutdown zone
may not be visible (e.g., fog, heavy rain), pile driving and removal
must be delayed until the PSO is confident marine mammals within the
shutdown zone can be detected.
<bullet> Pre-activity Monitoring--Before starting 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 30 minutes. The shutdown zone would be
[[Page 15972]]
considered cleared when a marine mammal has not been observed within
the zone for those 30 minutes. 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. When a marine
mammal for which take is authorized is present in the harassment zone,
activities may begin. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones would commence.
<bullet> Soft Start--Soft-start procedures are believed to provide
additional protection to marine mammals by warning and/or giving marine
mammals a chance to leave the area before the hammer operates at full
capacity. For impact pile driving, COK must provide an initial set of
three strikes from the hammer at reduced energy, followed by a 30-
second waiting period. This procedure would be conducted 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 30 minutes or longer.
<bullet> Installation--Vibratory installation would be used as the
primary method of pile installation to minimize impacts on marine
mammals and their prey. Impact driving would be minimized and used only
as needed to seat the pile in its final position or penetrate material
too dense for a vibratory hammer.
<bullet> Scheduling--Pile driving or removal activities must occur
during daylight hours. Actual daily durations would not exceed 12 hours
of in-water work. As only one pile would be driven per day, it is
extremely unlikely that any work would extend into the night. This
would only occur if there is a safety risk to leaving any structure as-
is until the following day when the sun has risen. If poor
environmental conditions restrict visibility of the shutdown zones
(e.g., from excessive wind or fog, high Beaufort sea state), pile
installation may not be initiated. Work begun with a fully cleared
Level B harassment zone may continue during inclement weather (e.g.,
fog, heavy rain) or periods of limited visibility.
<bullet> Establishment of Shutdown Zones--Shutdown zones for all
pile driving and removal activities have been established and can be
found in table 10. A shutdown zone generally defines an area where the
activity would shut down upon sighting a marine mammal (or anticipating
an animal to enter the defined area). Shutdown zones would vary based
on the activity type and marine mammal hearing group (table 3).
Although only one pile would be installed per day, due to sediment
characteristics and variation in pile sizes, COK does not know how much
time would be required for vibratory driving/removal and DTH
installation at each pile or how many strikes would be required for
impact installation. Given this uncertainty and concerns related to
ESA-listed humpback whales and fin whales, COK would use a tiered
system to identify and monitor appropriate shutdown zones based on
activity duration or the number of strikes required for pile
installation or removal. During vibratory driving/removal and DTH pile
installation, the shutdown zone size initially would be set at the
largest tier or maximum scenario for the day (according to the defined
duration intervals in tables 7 and 10). This will determine the
appropriate Level A harassment isopleths and associated shutdown zones
for that day. Therefore, the start of each day will assume a shutdown
zone size for 14 hours of vibratory driving/removal and 8 hours of DTH
installation. Shutdown zones would be reduced to the smaller zone
(i.e., the shutdown zone size for 8 hours of vibratory driving/removal
and 4 hours of DTH installation) if conditions indicate that less time
for installation/removal is necessary. Similarly, for impact driving,
the shutdown zone initially would be set to the largest tier or maximum
scenario at the start of the day (i.e., the shutdown zone size for
1,001-1,500 strikes). If, as the activity progresses, fewer than 1,000
strikes are expected, the shutdown zone could decrease to either Tier 2
(the shutdown zone size from 501-1,000 strikes) or Tier 1 (the shutdown
zone size from 0-500 strikes).
<bullet> If a marine mammal enters or is observed within an
established shutdown zone, pile driving must be halted or delayed. Pile
driving may not commence or resume until either the animal has
voluntarily left and been visually confirmed beyond the shutdown zone,
or 15 minutes have passed without subsequent detections.
<bullet> All personnel, including construction supervisors and
crews, PSOs, and relevant staff, must avoid direct physical interaction
with marine mammals during construction activity. If a marine mammal
comes within 10 m of such activity, operations must cease, and vessels
must reduce speed to the minimum level required to maintain steerage
and safe working conditions, as necessary to avoid direct physical
interaction.
<bullet> For those marine mammals for which take has not been
authorized, in-water pile installation and removal would shut down
immediately if such species are observed within or entering the Level A
or Level B harassment zone.
<bullet> If take reaches the authorized limit for an authorized
species, pile installation and removal would be stopped as these
species approach the Level A or Level B harassment zone to avoid
additional take.
Table 10--Shutdown and Monitoring Zones for Each Driving/Removal Activity
----------------------------------------------------------------------------------------------------------------
Low High Very high
frequency frequency frequency Phocid Otariid Level B
Pile size cetacean cetacean cetacean pinniped pinniped harassment
shutdown shutdown shutdown shutdown shutdown zone (m)
area (m) area (m) area (m) area (m) area (m)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
30-, 36-inch piles up to 8 hrs.... 80 40 70 110 40 11,660
30-, 36-inch piles up to 14 hrs... 120 50 100 150 50
48-inch piles up to 8 hrs......... 180 70 140 230 80 \1\ 12,500
48-inch piles up to 14 hrs........ 250 100 210 300 110
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
30-inch piles 1-500 strikes (10 250 40 300 230 90 1,000
min).............................
30-inch piles 501-1,000 strikes 400 60 300 300 140
(20 min).........................
30-inch piles 1,001-1,500 strikes 520 70 300 300 180
(30 min).........................
[[Page 15973]]
36-inch piles 1-500 strikes (10 630 80 300 300 210 1,590
min).............................
36-inch piles 501-1,000 strikes 1,000 130 300 300 300
(20 min).........................
36-inch piles 1,001-1,500 strikes 1,310 170 300 300 300
(30 min).........................
48-inch piles 1-500 strikes (10 400 60 300 300 140 1,360
min).............................
48-inch piles 501-1,000 strikes 630 90 300 300 210
(20 min).........................
48-inch piles 1,001-1,500 strikes 830 110 300 300 280
(30 min).........................
----------------------------------------------------------------------------------------------------------------
DTH Socket
----------------------------------------------------------------------------------------------------------------
30-, 36-inch piles up to 4 hrs.... 1,030 140 300 300 300 12,500
30-, 36-inch piles up to 8 hrs.... 1,640 210 300 300 300
48-inch piles up to 4 hrs......... 1,910 250 300 300 300 12,500
48-inch piles up to 8 hrs......... \2\ 2,000 390 300 300 300
----------------------------------------------------------------------------------------------------------------
DTH Anchor
----------------------------------------------------------------------------------------------------------------
12-inch up to 4 hrs............... 70 10 180 70 30 12,500
----------------------------------------------------------------------------------------------------------------
\1\ Represents the largest Level B Harassment isopleth. Note that land masses truncate the isopleth at 12,500 m.
\2\ 2,000 m (2 km) is the maximum realistic expectation for sighting large mysticetes.
NMFS notes that sighting ranges for species depend on the species'
size and activity level in combination with observer positioning. For
example, a realistic expectation for sighting large mysticetes is a
maximum of approximately 2 km. Similarly, it would be difficult for
PSOs to see small or cryptic species at ranges over approximately 300 m
(e.g., harbor seals and harbor porpoises). Shutdown zones for these
species are therefore smaller than the calculated Level A harassment
isopleths, and Level A take for these species has been proposed.
Additionally, NMFS notes that shutdown zones are rounded up to the
nearest 10 m from the AUD INJ onset isopleth.
NMFS and the applicant considered the use of a bubble curtain as a
mitigation measure. Bubble curtains are used to reduce the extent of
the ensonified areas as well as reduce the sound levels within the
ensonified areas. However, the applicant has not proposed a bubble
curtain as a mitigation measure because sound transmission would be
truncated by land masses, thereby obstructing sound transmission and
confining the action area. These land masses are Revillagigedo Island,
Gravina Island, Pennock Island, and Spire Island, at approximately 12.5
km to the southeast and approximately 3.59 km northwest of the project
area. Given the proposed locations of PSOs and the relatively narrow
channels, NMFS concurs that use of a bubble curtain is not necessary to
effect the least practicable adverse impact on marine mammals.
In summary, based on our evaluation of the applicant's proposed
measures, NMFS has preliminarily determined that the 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
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 would 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 to
compliance and ensuring 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 the: (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
Qualified, NMFS-approved PSOs must conduct monitoring in accordance
with COK's Marine Mammal Monitoring Plan and Section 5 of the IHA. PSOs
would be present during all pile installation and removal activities,
including vibratory, impact, and DTH methods, in accordance with the
following:
[[Page 15974]]
<bullet> Observer training must be provided before the project
starts 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).
<bullet> All PSOs must have no other project-related tasks while
conducting monitoring.
<bullet> PSOs shall be placed at 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.
<bullet> 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 the 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.
<bullet> At least three PSOs would be on duty during all vibratory
installation/removal, impact installation, and DTH. PSOs would be
stationed along Tongass Narrows at locations that provide optimal
visual coverage for shutdown and monitoring zones (see figure 3 in
COK's Marine Mammal Monitoring Plan). PSOs would monitor for marine
mammals entering the Level B harassment zones; the position(s) may vary
based on the construction activity and the location of piles or
equipment. To maximize the visual coverage of shutdown and monitoring
zones, observers would use elevated platforms at observation points to
the extent practicable. Observers would contact each other via two-way
radio and a cellular phone used as backup communication.
<bullet> PSOs would scan the waters using binoculars and/or
spotting scopes and a handheld range-finder device to verify the
distance to each sighting from the project site.
PSO Qualifications
<bullet> COK would adhere to the following PSO qualifications: (i)
Independent observers (i.e., not construction personnel) are required;
(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) COK must submit observer curricula vitae for approval by NMFS.
<bullet> Additional standard observer qualifications include: (i)
Ability to conduct field observations and collect data according to
assigned protocols; (ii) Experience or training in the field
identification of marine mammals, including the identification of
behaviors; (iii) Sufficient training, orientation, or experience with
the construction operation to provide for personal safety during
observations; (iv) 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 (v) 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 or 60 days before the requested date of issuance of any
future IHAs for projects at the exact location, whichever comes first.
The report 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 (beginning and end) of all marine mammal
monitoring;
<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, vibratory, or DTH);
<bullet> PSO locations during marine mammal monitoring; and
<bullet> Environmental conditions during monitoring periods (at the
beginning and end of a PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions, including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance. Upon
observation of a marine mammal, the following information is required:
<bullet> The name of the PSO who sighted the animal(s), the PSO's
location, and activity at the time of the sighting;
<bullet> The time of the sighting;
<bullet> Identification of the animal(s) (e.g., genus/species,
lowest possible taxonomic level, or unidentified), the PSO's confidence
in identification, and the composition of the group if there is a mix
of species;
<bullet> The distance and bearing of each marine mammal observed
relative to the pile being driven for each sighting (if pile driving
was occurring at the time of sighting);
<bullet> The estimated number of animals (min/max/best estimate);
<bullet> The estimated number of animals by cohort (adults,
juveniles, neonates, group composition, sex class, etc.);
<bullet> The animal's closest point of approach and estimated time
spent within the harassment zone;
<bullet> A 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> The number of marine mammals detected within the
harassment zones by species (differentiated by month as appropriate);
and
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and the resulting changes in the behavior
of the animal(s), if any.
Finally, COK must also submit all PSO datasheets and/or raw
sighting data in an electronic tabular format with the draft report, as
specified in Section 6 of the IHA. If no comments are received from
NMFS within 30 days, the draft 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 causes the
take of a marine mammal in a manner prohibited by the IHA (if issued),
such as an injury,
[[Page 15975]]
serious injury, or mortality, COK must immediately cease the specified
activities and report the incident to the NMFS Office of Protected
Resources (<a href="/cdn-cgi/l/email-protection#d08082fe998480fe9dbfbeb9a4bfa2b9beb782b5a0bfa2a4a390bebfb1b1feb7bfa6"><span class="__cf_email__" data-cfemail="461614680f1216680b29282f3229342f282114233629343235062829272768212930">[email protected]</span></a>), and the NMFS Alaska 24-
hour Regional Stranding Hotline (877) 925-7773 or (877) 9-AKR-PRD. The
report must include the following information:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> General circumstances under which the animal was
discovered.
Activities would not resume until NMFS can review the circumstances
surrounding the prohibited take. NMFS would work with COK to determine
what is necessary to minimize the likelihood of further prohibited take
and ensure MMPA compliance. COK cannot resume their activities until
NMFS has notified them via letter, email, or telephone.
If COK 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), then COK would
immediately report the incident to the NMFS Office of Protected
Resources (<a href="/cdn-cgi/l/email-protection#1b4b4935524f4b35567475726f746972757c497e6b74696f685b75747a7a357c746d"><span class="__cf_email__" data-cfemail="83d3d1adcad7d3adceecedeaf7ecf1eaede4d1e6f3ecf1f7f0c3edece2e2ade4ecf5">[email protected]</span></a>), and the NMFS Alaska 24-
hour Regional Stranding Hotline at (877) 925-7773 or (877) 9-AKR-PRD.
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 COK to
determine whether modifications in the activities are appropriate.
Finally, in the event that COK 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), COK would report the incident to
the Chief of the Permits and Conservation Division, 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. COK 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 discussion of our analysis applies to all
the species listed in table 8, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar. There is little information about the nature or the
severity of the impacts or the size, status, or structure of any of
these species or stocks that would lead to a different analysis for
this activity.
Pile driving, removal, and DTH activities associated with the
project, as outlined previously, have the potential to disturb or
displace marine mammals. Specifically, the specified activities may
result in take in the form of Level A harassment and Level B harassment
from underwater sounds generated from 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.
Given the nature of the activity, NMFS does not anticipate serious
injury or mortality due to COK's planned project, even in the absence
of required mitigation. The Level A harassment zones identified in
table 7 are based upon an animal exposed to vibratory pile driving,
impact pile driving, and DTH pile installation for periods ranging from
up to 30 minutes for impact driving, up to 14 hours for vibratory
driving/removal (although actual daily durations would not exceed 12
hours, and may be less than 12 hours), and up to 8 hours for DTH.
Exposures of this length are, however, unlikely for vibratory driving/
removal and DTH pile installation scenarios, given marine mammal
movement throughout the area. Even during impact driving scenarios, an
animal exposed to the accumulated sound energy would likely only
experience limited AUD INJ at the lower frequencies where pile driving
energy is concentrated.
As stated in the Proposed Mitigation section, COK would implement
shutdown zones that equal or exceed many of the Level A harassment
isopleths shown in table 7. Take by Level A harassment is authorized
for 7 marine mammal species (8 stocks). This is precautionary to
account for the potential that an animal could enter and remain within
the area between a Level A harassment zone and the shutdown zone for
long enough to be taken by Level A harassment. Additionally, in some
cases, this precaution would account for the possibility that an animal
could enter a shutdown zone without detection, given the various
obstructions along the shoreline, and remain in the Level A harassment
zone for a duration long enough to be taken by Level A harassment
before being observed and a shutdown occurring. That said, any take by
Level A harassment is expected to arise from, at most, a small degree
of AUD INJ because animals would need to be exposed to higher levels
and/or longer duration than are expected to occur here to incur any
more than a small degree of AUD INJ. Additionally, and as noted
previously, some subset of the individuals that are behaviorally
harassed could also simultaneously incur some small degree of TTS for a
short duration of time. Because of the small degree anticipated, any
AUD INJ or TTS potentially incurred here is not expected to adversely
impact individual
[[Page 15976]]
fitness, let alone annual rates of recruitment or survival.
For all species and stocks, take is expected to occur within a
limited, confined area (adjacent to the project site) of the stock's
range. The intensity and duration of take by Level A and Level B
harassment would be minimized through the mitigation measures described
herein. Further, the amount of take authorized is small compared to the
stock abundance.
Behavioral responses of marine mammals to pile driving, pile
removal, and DTH at the project site, if any, are expected to be mild,
short-term, and temporary. Given that the installation of 12 permanent
piles and 16 temporary piles would occur over 8 months, any harassment
would be temporary and intermittent. Effects on individuals that are
taken by Level B harassment, based on reports in the literature as well
as monitoring from other similar activities, would likely be limited to
reactions such as increased swimming speeds, increased surfacing time,
or decreased foraging (if such activity were occurring) (e.g., Thorson
and Reyff 2006; Henningson, Durham, and Richardson, Inc. (HDR) 2012;
ABR 2016). Most likely, for pile driving, individuals would move away
from the sound source and be temporarily displaced from the areas of
pile driving. However, this reaction has been observed primarily
associated with impact pile driving. While vibratory driving associated
with the proposed project may produce sound at distances of many
kilometers from the project site, thus overlapping with some likely
less-disturbed habitat, the project site itself is located in a busy
harbor, and the majority of sound fields produced by the specified
activities are close to the harbor. Animals disturbed by project sounds
would be expected to avoid the area and use nearby higher-quality
habitats.
The potential for harassment is minimized by implementing the
proposed mitigation measures. During all impact driving, implementation
of soft start procedures and monitoring of established shutdown zones
shall be required, significantly reducing any possibility of injury.
Given sufficient notice through soft start (for impact driving), marine
mammals are expected to move away from an irritating sound source
before it becomes potentially injurious. To reduce the severity of in-
water noise, vibratory pile driving would be the primary installation
method for the project, and impact hammers would only be used to seat
pile tips into fractured bedrock ahead of the hammering operations or
if the material is too dense to penetrate with a vibratory hammer.
Any effects on marine mammal prey during in-water construction
would have a short-term impact on individual marine mammals' foraging
and likely no effect on the populations of marine mammals. Indirect
effects on marine mammal prey during the construction are expected to
be minor, and these effects are unlikely to cause substantial effects
on marine mammals at the individual level, with no expected impact on
annual rates of recruitment or survival.
The area likely impacted by the project is relatively small
compared to the available habitat in the surrounding waters of
Southeast Alaska and Tongass Narrows. Although Tongass Narrows is part
of an identified BIA for feeding humpback whales (NOAA 2023, Wild et
al. 2023), the timing of the BIA (May through September) only overlaps
with the proposed timing of the in-water construction (October through
May) for one month (May). Additionally, humpback foraging efforts
within Tongass Narrows are likely comparatively low due to the lower
value of the habitat in the immediate area (Wild et al. 2023), as
evidenced by the typically low occurrence of humpback whales in the
area. Finally, there is no ESA-designated critical habitat in the area
for humpback or fin whales.
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 proposed
for authorization;
<bullet> Any Level A harassment exposures are anticipated to result
in slight AUD INJ (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 area affected by the specified activity is very small
relative to the overall habitat ranges of all species, does not include
any rookeries, does not include ESA-designated critical habitat, and
only temporally overlaps with the southeast Alaska humpback whale
feeding BIA for one month (May) of the planned eight months of
activity;
<bullet> The project area is located in an industrialized and
commercial marina; and
<bullet> The proposed mitigation measures, such as employing
vibratory driving to the maximum extent practicable, soft-starts, and
shutdowns, are expected to reduce the effects of the specified activity
to the least practicable adverse impact level.
In combination, we believe that these factors, as well as the
available body of evidence from other similar activities, demonstrate
that the potential effects of the specified activities would have only
minor, short-term effects on individuals. The specified activities are
not expected to affect the reproduction or survival of any individual
marine mammal and, therefore, would not affect the recruitment or
survival rates for any species or stock.
Based on the analysis of the likely effects of the specified
activity on marine mammals and their habitat and considering the
implementation of the proposed monitoring and mitigation measures, NMFS
preliminarily finds that the total number of marine mammals taken from
the proposed activity would have a negligible impact on all affected
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 less 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 7 demonstrates the number of animals that could be exposed to
the received noise levels that could cause Level A and Level B
harassment for the proposed work in the Port of Ketchikan. Our analysis
shows that less than one-third of each affected stock could be taken by
harassment. The number 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.
[[Page 15977]]
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 would not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
that is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by (i) causing the
marine mammals to abandon or avoid hunting areas, (ii) directly
displacing subsistence users, or (iii) placing physical barriers
between the marine mammals and the subsistence hunters, and (2) that
cannot be sufficiently mitigated by other measures to increase the
availability of marine mammals to allow subsistence needs to be met.
Alaska Native hunters in the Ketchikan vicinity do not
traditionally harvest cetaceans (Muto et al. 2019). Harbor seals are
the most commonly targeted marine mammal, and Alaska Native subsistence
hunters hunt them within the Ketchikan area. In 2012, an estimated 595
harbor seals were taken for subsistence uses, with 22 occurring in
Ketchikan (Wolfe et al. 2013). This is the most recent data available.
The harbor seal harvest per capita was low, at 0.02 for the Ketchikan
community. As for Steller sea lions, subsistence data for Southeast
Alaska shows that from 1995 through 2008, plus 2012 through 2015, a
total of 20 to 29 Steller sea lions were harvested by Alaska Native
hunters, with typical harvest years ranging from 0 to 6 animals (Alaska
Department of Fish & Game n.d.). In 2012, it was estimated that nine
Steller sea lions were taken in Southeast Alaska, and only from Hoonah
and Sitka (Wolfe et al. 2013).
Based on the available information, there are no known haul-out
locations for either species in the project area. The harbor seal and
the Steller sea lion may be temporarily displaced from the project
area. However, neither the local population nor individual pinnipeds
are likely to be adversely impacted by the proposed action beyond
noise-induced harassment or slight injury, nor is the activity expected
to impact subsistence hunting of pinnipeds or other marine mammals.
Accordingly, NMFS has preliminarily determined that there will not be
an unmitigable adverse impact on subsistence uses from the COK
activities.
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.)
requires that each Federal agency ensure 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 issuing IHAs, NMFS consults internally
whenever we propose to authorize take for endangered or threatened
species, in this case, with the NMFS Alaska Regional Office.
NMFS is proposing to authorize the take of fin whales and the
Mexico-North Pacific stock of humpback whales, listed as endangered and
threatened, respectively, under the ESA.
The Permits and Conservation Division has requested the initiation
of ESA section 7 consultation with the Alaska Region for the issuance
of this IHA. NMFS would conclude the ESA consultation before reaching a
determination regarding the proposed authorization issuance.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the City of Ketchikan for conducting the in-water
construction activities as part of the Berth III New Mooring Dolphins
Project in Ketchikan between October 1, 2025, and September 30, 2026,
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 comments on our analyses, the proposed authorization,
and any other aspect of this notice of proposed IHA for the proposed
Berth III New Mooring Dolphins Project. We also request comments on the
potential renewal of this proposed IHA, as described in the paragraph
below. Please include any supporting data or literature citations with
your comments 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 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
before the needed renewal IHA effective date (recognizing that the
renewal IHA expiration date cannot extend beyond 1 year from the
expiration of the initial IHA).
<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).
(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.
<bullet> 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 would remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: April 10, 2025.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2025-06437 Filed 4-15-25; 8:45 am]
BILLING CODE 3510-22-P
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