Notice2025-05775
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Alaska Railroad Corporation Seward Freight Dock Construction in Seward, Alaska
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
April 4, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the Alaska Railroad Corporation (ARRC) for authorization to take marine mammals incidental to the Seward Freight Dock construction project in Seward, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an incidental harassment authorization (IHA) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, 1-year renewal that could be issued under certain circumstances and if all requirements are met, as described in the Request for Public Comments section at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorization and agency responses will be summarized in the final notice of our decision.
Full Text
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<title>Federal Register, Volume 90 Issue 64 (Friday, April 4, 2025)</title>
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[Federal Register Volume 90, Number 64 (Friday, April 4, 2025)]
[Notices]
[Pages 14792-14812]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-05775]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE763]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Alaska Railroad Corporation Seward
Freight Dock Construction in Seward, 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 Alaska Railroad
Corporation (ARRC) for authorization to take marine mammals incidental
to the Seward Freight Dock construction project in Seward, Alaska.
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting
comments on its proposal to issue an incidental harassment
authorization (IHA) to incidentally take marine mammals during the
specified activities. NMFS is also requesting comments on a possible
one-time, 1-year renewal that could be issued under certain
circumstances and if all requirements are met, as described in the
Request for Public Comments section at the end of this notice. NMFS
will consider public comments prior to making any final decision on the
issuance of the requested MMPA authorization and agency responses will
be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than May 5,
2025.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division,
[[Page 14793]]
Office of Protected Resources, National Marine Fisheries Service and
should be submitted via email to <a href="/cdn-cgi/l/email-protection#94ddc0c4bafcf5e6f8f5f7fcf1e6d4fafbf5f5baf3fbe2"><span class="__cf_email__" data-cfemail="c1889591efa9a0b3ada0a2a9a4b381afaea0a0efa6aeb7">[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: Jenna Harlacher, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms used above are included in the relevant sections below
and 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)
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NAO 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has preliminarily determined
that the issuance of the proposed IHA qualifies to be categorically
excluded from further NEPA review.
Summary of Request
On April 23, 2024, NMFS received a request from the ARRC for an IHA
to take marine mammals incidental to pile driving activity associated
with the Seward Freight Dock construction project in Seward, Alaska.
Following NMFS' review of the application, we received a revised
version of the application on September 30, 2024. After finalizing
further discussions and clarifications, the ARRC submitted revised
versions on November 20, 2024, and February 4, 2025, followed by a
final revised version on March 5, 2025, which was deemed adequate and
complete on March 6, 2025. ARRC's request is for take of 11 species of
marine mammals by Level B harassment, and for a subset, by Level A
harassment. Neither ARRC nor NMFS expect serious injury or mortality to
result from this activity and, therefore, an IHA is appropriate.
Description of Proposed Activity
Overview
The ARRC requested an IHA to expand the freight dock to improve
safety and efficiency for the movement of goods, by better separating
pedestrian traffic from freight and heavy truck traffic, enhance safety
and efficiency of stevedoring activities, preserve the intermodal
operations of commercial freight customers, accommodate larger vessels,
and enhance the long-term utility of the dock. This project entails
both onshore and in-water construction activities including dock
expansion, pile removal and installation, and upland construction.
The ARRC proposes to construct an expansion of their existing
Freight Dock in Seward, Alaska. The new dock extension will be an OPEN
CELL SHEET PILE\TM\ (OCSP\TM\) bulkhead backed by a rock revetment,
consistent with the existing dock. This type of bulkhead is a flexible
steel sheet pile membrane supported by soil contact with the embedded
steel sheet pile tail walls. The dock face will be extended by 375 feet
(ft) (114.3 meters (m)); the usable width of the new extension will be
300 ft. The existing dock uplands will also be widened to 300 ft (91.4
m), further expanding the fill footprint and revetment to the east.
Dock upland facilities will be improved, including the installation and
upgrades of dock utilities, rails, etc. The dock extension will include
typical components, such as fenders, mooring bollards, sacrificial
anodes, and bullrail. South of the new dock extension, a salvaged
mooring dolphin and catwalk (new or salvaged) will be installed.
The only parts of the overall project that may result in Level A
and Level B harassment, and thus the only parts further analyzed in
this notice, are the in-water and upland construction activities
associated with vibratory and impact pile driving.
Dates and Duration
Pile driving and in-water work on the Freight Dock will require
approximately 12 months beginning in November 2026. Upland
vibrocompaction operations are expected to need 3 months, overlapping
the in-water work period. The ARRC estimates a total of 155 days of in-
water pile driving activity and 106 days of upland construction with a
maximum number of 219 construction days, as some days will include both
in-water and upland work. The IHA would be valid from November 1, 2026,
through October 31, 2027.
[[Page 14794]]
Specific Geographic Region
The proposed project is located in Seward, Alaska, on the Kenai
Peninsula and at the head of Resurrection Bay. The Freight Dock is
positioned at the head of the bay between the Resurrection River delta
and the Seward Small Boat Harbor.
BILLING CODE 3510-22-P
[GRAPHIC] [TIFF OMITTED] TN04AP25.000
BILLING CODE 3510-22-C
Detailed Description of the Specified Activity
The ARRC proposes to expand and improve the existing Freight Dock
to improve safety and accommodate increasing need. This proposed
project will include the removal of 4 existing piles via vibratory
driving, the installation and removal of 60 temporary piles via
vibratory driving, installation of 456 permanent piles via vibratory
pile driving, and installation of 4 piles via vibratory and impact pile
driving. ARRC plans to install 24-inch (in) (61 centimeter (cm)) to 30-
in (76.2 cm) steel pipe piles, sheet pile pairs, and H-piles for their
new infrastructure. Additionally, the ARRC proposes upland construction
including removal of 1 steel pile via vibratory removal and
installation of 5 steel piles via vibratory pile driving, and
installation and removal of 2,157 steel H-piles via vibrocompaction.
Vibrocompaction uses an H-pile with ``displacement angles'' probed with
vibratory pile-driving equipment to consolidate and compact fill. All
of these activities may result in incidental take of marine mammals.
[[Page 14795]]
Table 1--Number and Type of Piles To Be Installed and Removed
----------------------------------------------------------------------------------------------------------------
Activity duration
Method Pile size and type (minutes Max piles Number Estimated
(strikes)/piles) per day of piles days of work
----------------------------------------------------------------------------------------------------------------
Uplands Removal and Install
----------------------------------------------------------------------------------------------------------------
Vibratory removal............... 24-in steel pile... 30 1 1 1
Vibratory Install and removal... H-pile............. 30 20 2,157 100
Vibratory install............... 30-in steel pile... 60 1 1 2
Vibratory install............... 30-in steel pile... 30 3 3 3
----------------------------------------------------------------------------------------------------------------
In-water Removal and Install
----------------------------------------------------------------------------------------------------------------
Vibratory removal............... 24-in steel pile... 90 4 4 4
Vibratory install and removal 24-in steel pile... 60 6 60 50
(temporary piles).
Vibratory Install............... Sheet pile pair.... 30 20 425 75
Vibratory Install............... H-pile............. 60 2 14 15
Vibratory Install (Fender)...... 30-in steel pile... 60 4 14 6
Vibratory Install (Dolphin)..... 30-in steel pile... 60 2 4 \1\ 5
Impact install.................. 30-in steel pile... 1,800 2 4
----------------------------------------------------------------------------------------------------------------
\1\ Five total days for both vibratory and impact because the construction plan is not finalized. This is based
on a worst case scenario option.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, 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 Endangered Species Act (ESA) and potential biological
removal (PBR), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no serious injury or mortality is anticipated or proposed
to be authorized here, PBR and annual serious injury and mortality (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 make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Alaska Marine Mammal SARs. All values presented in table 2
are the most recent available at the time of publication (including
from the draft 2024 SARs) 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>.
Table 2--Species \1\ With Estimated Take From the Specified Activities
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
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Order Artiodactyla--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'i \6\............ -, -, N 11,278 (0.56, 7,265, 127 27.09
2020).
Humpback Whale.................. Megaptera novaeangliae. Mexico-North Pacific... T, D, Y N/A (N/A, N/A, 2006) UND 0.57
\7\.
Humpback Whale.................. Megaptera novaeangliae. Western North Pacific.. E, D, Y 1,084 (0.088, 1,007, \8\ 3.4 5.82
2006).
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Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
[[Page 14796]]
Killer Whale.................... Orcinus orca........... Eastern North Pacific -, -, N 1,920 (N/A, 1,920, 19 1.3
Alaska Resident. 2019) \9\.
Killer Whale.................... Orcinus orca........... AT1 Transient.......... -, D, Y 7 (N/A, 7, 2019) \10\. 0.1 0
Killer Whale.................... Orcinus orca........... Eastern North Pacific -, -, N 587 (N/A, 587, 2012) 5.9 0.8
Gulf of Alaska, \11\.
Aleutian Islands and
Bering Sea Transient.
Pacific White-Sided Dolphin..... Lagenorhynchus North 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
\12\.
Harbor Porpoise................. Phocoena phocoena...... Gulf of Alaska......... -, -, Y 31,046 (0.21, N/A, UND 72
1998).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
CA Sea Lion..................... Zalophus californianus. United States.......... -, -, N 257,606 (N/A, 233,515, 14,011 >321
2014).
Steller Sea Lion................ Eumetopias jubatus..... Western................ E, D, Y 49,837 (N/A, 49,837, 299 267
2022) \13\.
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... Prince William Sound... -, -, N 44,756 (N/A, 41,776, 1,253 413
2015).
Northern Elephant Seal.......... Mirounga angustirostris California 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>; Committee on Taxonomy, 2022).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\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\ PBR in U.S. waters = 0.2, M/SI in U.S. waters = 0.06.
\9\ Nest is based upon counts of individuals identified from photo-ID catalogs.
\10\ Nest is based upon counts of individuals identified from photo-ID catalogs. PBR has been calculated, however, a reliable estimate of the maximum
net productivity rate is not available for this stock, and the default cetacean maximum theoretical net productivity rate was used for the PBR
calculation.
\11\ Nest is based upon counts of individuals identified from photo-ID catalogs.
\12\ 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.
\13\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the United
States only. The overall Nmin is 73,211 and overall PBR is 439.
As indicated above, all 11 species (with 15 managed stocks) in
table 2 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. While sperm whales
(Physeter macrocephalus), eastern U.S. Steller sea lions, North Pacific
right whales (Eubalaena japonica), blue whales (Balaenoptera musculus),
sei whales (Balaenoptera borealis), and beluga whales (Delphinapterus
leucas) are included in the biological assessment, these species do not
occur in inner Resurrection Bay and are more commonly found along the
vessel transit routes analyzed in the Biological Assessment. Thus, the
temporal and/or spatial occurrence of these species is such that take
is not expected to occur, and they are not discussed further beyond the
explanation provided here.
In addition, northern sea otters (Enhydra lutris) may be found in
Seward, Alaska. However, sea otters are managed by the U.S. Fish and
Wildlife Service and are not considered further in this document.
In addition to what is included in sections 3 and 4 of the IHA
application, and NMFS' website, further detail informing our analysis
on the regional occurrence for select species of particular or unique
vulnerability (i.e., information regarding ESA listed species) is
provided below.
Fin Whale
Fin whales are found in the Gulf of Alaska year-round. They
typically inhabit deep, offshore waters, but a portion of the northeast
Pacific stock (ESA-endangered) habitually utilizes inshore waters of
the Kitimat Fjord System in coastal British Columbia, Canada; and fin
whales have occasionally been observed in inside waters of southeast
Alaska and Prince William Sound (Keen et al., 2018; Ferguson et al.,
2015). Similar hydrographic conditions to those of fin whale inhabited
areas of the Kitimat Fjord System are found in the outer reaches of
Resurrection Bay and the Harding Gateway (Heggie et al., 1977).
Although most commonly sighted in outer Resurrection Bay, available
occurrence data from the Global Biodiversity Information Facility
(GBIF) show that fin whales have been observed as far into Resurrection
Bay as the northern tip of Fox Island (GBIF, 2022c), with reported
sightings in inner Resurrection Bay in 2019, 2023, and 2024 (GBIF,
2024c; Happywhale, 2025). There are no designated critical habitats
[[Page 14797]]
for fin whales and there are no biologically important areas in the
action area.
Humpback Whale
Three stocks of humpback whales could be found in the project area.
These include--the Hawai[revaps]i, Mexico-North Pacific Stock (ESA-
threatened), and the western North Pacific Stock (ESA-endangered).
Although humpbacks seasonally migrate, they are observed in inner
Resurrection Bay regularly throughout the summer season (May through
August) and may venture into the outer bay year-round (McCaslin 2019;
GBIF, 2022a). There are no designated critical habitats or biologically
important areas for humpback whales in the action area.
Steller Sea Lion
Only the western stock (ESA-endangered) of Steller sea lion is
likely to occur in the action area. Womble et al. (2009) characterized
Steller sea lion distribution in southeast Alaska in relation to
seasonally available prey resources. Womble et al. identified four
types of seasonal haulouts based on prey type and Resurrection Bay is
characteristic of all four site types (ADF&G, 2022a; Brown et al.,
2002). The year-round availability of prey resources in Resurrection
Bay (especially at the head of the bay) make it excellent foraging
habitat for Steller sea lions.
It is anticipated that Steller sea lions will be present in the
range of the project area year-round, with fewer individuals during the
breeding season (late May through early June) when breeding females and
mature males congregate at rookeries.
Reports from professional tour boat captains based in Seward
indicate that at least 5 to 10 Steller sea lions can be found foraging
daily throughout inner Resurrection Bay, often near Seward Harbor.
Other areas where Steller sea lions are commonly observed within inner
Resurrection Bay include Lowell Point, Tonsina Point, and Fourth of
July Beach (Personal communication, 2022).
The proposed action does not overlap with Steller sea lion critical
habitat or any major haulouts and rookeries. The closest major haulouts
to the action are at the mouth of Resurrection Bay, on the Resurrection
Peninsula (20.95 kilometers (km) from the proposed action area) and on
Hive Island (25.72 km from the proposed action area). The closest
Steller sea lion rookery is the Chiswell Islands (approximately 54 km
from the proposed action area).
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Generalized hearing ranges were
chosen based on the ~65 decibel (dB) threshold from composite
audiograms, previous analyses in NMFS (2018), 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. Generalized hearing range
chosen based on ~65 dB threshold from composite audiogram, previous
analysis in NMFS, 2018, and/or data from Southall et al., 2007;
Southall et al., 2019. Additionally, animals are able to detect very
loud sounds above and below that ``generalized'' hearing range.
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2024) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take of Marine Mammals section, and the Proposed Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship of individuals
and whether those impacts are reasonably expected to, or reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival.
Acoustic effects on marine mammals during the specified activity
can occur from impact and vibratory pile driving. The effects of
underwater noise from ARRC's proposed activities have the potential to
result in Level A or Level B harassment of marine mammals in the action
area.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far. The sound level of an area is defined by the
total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g.,
[[Page 14798]]
sounds produced by marine mammals, fish, and invertebrates), and
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10 to 20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In-water construction activities associated with the project would
include vibratory pile removal, and impact and vibratory pile driving.
The sounds produced by these activities fall into one of two general
sound types: impulsive and non-impulsive. Impulsive sounds (e.g.,
explosions, gunshots, sonic booms, impact pile driving) are typically
transient, brief (less than 1 second), broadband, and consist of high
peak sound pressure with rapid rise time and rapid decay (ANSI, 1986;
NIOSH, 1998; ANSI, 2005; NMFS, 2018a). Non-impulsive sounds (e.g.,
aircraft, machinery operations such as drilling or dredging, vibratory
pile driving, and active sonar systems) can be broadband, narrowband or
tonal, brief or prolonged (continuous or intermittent), and typically
do not have the high peak sound pressure with raid rise/decay time that
impulsive sounds do (ANSI, 1995; NIOSH, 1998; NMFS, 2018a). The
distinction between these two sound types is important because they
have differing potential to cause physical effects, particularly with
regard to hearing (e.g., Ward 1997 in Southall et al., 2007).
ARRC proposes to use vibratory hammers to remove steel piles,
vibratory pile driving to install new steel pipe piles, sheet piles and
H-piles and impact pile driving to install new steel pipe piles
associated with the Seward Freight Dock project. Impact hammers operate
by repeatedly dropping a heavy piston onto a pile to drive the pile
into the substrate. Sound generated by impact hammers is characterized
by rapid rise times and high peak levels, a potentially injurious
combination (Hastings and Popper, 2005). Vibratory hammers install
piles by vibrating them and allowing the weight of the hammer to push
them into the sediment. Vibratory hammers produce significantly less
sound than impact hammers. Peak sound pressure levels (SPLs) may be 180
dB or greater, but are generally 10 to 20 dB lower than SPLs generated
during impact pile driving of the same-sized pile (Oestman et al.,
2009). Rise time is slower, reducing the probability and severity of
injury, and sound energy is distributed over a greater amount of time
(Nedwell and Edwards, 2002; Carlson et al., 2005).
The likely or possible impacts of ARRC's proposed activity on
marine mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors could result from the physical
presence of equipment and personnel; however, any impacts to marine
mammals are expected to be primarily acoustic in nature. Acoustic
stressors include effects of heavy equipment operation during pile
installation and removal.
Acoustic Effects
The introduction of anthropogenic noise into the aquatic
environment from pile driving and removal is the means by which marine
mammals may be harassed from ARRC's specified activity. In general,
animals exposed to natural or anthropogenic sound may experience
behavioral, physiological, and/or physical effects, ranging in
magnitude from none to severe (Southall et al., 2007, 2019). In
general, exposure to pile driving noise has the potential to result in
behavioral reactions (e.g., avoidance, temporary cessation of foraging
and vocalizing, changes in dive behavior) and, in limited cases, an
auditory threshold shift (TS). Exposure to anthropogenic noise can also
lead to non-observable physiological responses such an increase in
stress hormones. Additional noise in a marine mammal's habitat can mask
acoustic cues used by marine mammals to carry out daily functions such
as communication and predator and prey detection. The effects of pile
driving noise on marine mammals are dependent on several factors,
including, but not limited to, sound type (e.g., impulsive vs. non-
impulsive), the species, age and sex class (e.g., adult male vs. mom
with calf), duration of exposure, the distance between the pile and the
animal, received levels, behavior at time of exposure, and previous
history with exposure (Wartzok et al., 2004; Southall et al., 2007).
Here we discuss physical auditory effects (TSs) followed by behavioral
effects and potential impacts on habitat.
NMFS defines a noise-induced TS as a change, usually an increase,
in the threshold of audibility at a specified frequency or portion of
an individual's hearing range above a previously established reference
level (NMFS, 2018, 2024). The amount of TS is customarily expressed in
dB. A TS can be permanent or temporary. As described in NMFS (2018,
2024), there are numerous factors to consider when examining the
consequence of TS, including, but not limited to, the signal temporal
pattern (e.g., impulsive or non-impulsive), likelihood an individual
would be exposed for a long enough duration or to a high enough level
to induce a TS, the magnitude of the TS, time to recovery (seconds to
minutes or hours to days), the frequency range of the exposure (i.e.,
spectral content), the hearing and vocalization frequency range of the
exposed species relative to the signal's frequency spectrum (i.e., how
animal uses sound within the frequency band of the signal; e.g.,
Kastelein et al., 2014), and the overlap between the animal and the
source (e.g., spatial, temporal, and spectral).
Auditory Injury (AUD INJ) and Permanent Threshold Shift (PTS)--NMFS
defines AUD INJ as ``damage to the inner ear that can result in
destruction of tissue . . . which may or may not result in PTS'' (NMFS,
2024). 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). PTS does not generally affect more than a limited
frequency range, and an animal that has incurred PTS has incurred some
level of hearing loss at the relevant frequencies; typically, animals
with PTS are not functionally deaf (Au and Hastings, 2008; Finneran,
2016). Available data from humans and other terrestrial mammals
indicate that a 40-dB threshold shift approximates PTS onset (see Ward
et al., 1958, 1959, 1960; Kryter et al., 1966; Miller, 1974; Ahroon et
al., 1996; Henderson et al., 2008). PTS levels for marine mammals are
estimates, as with the exception of a single study unintentionally
inducing PTS in a harbor seal (Kastak et al., 2008), there are no
empirical data measuring PTS in marine mammals largely due to the fact
that, for various ethical reasons, experiments involving
[[Page 14799]]
anthropogenic noise exposure at levels inducing PTS are not typically
pursued or authorized (NMFS, 2018).
Temporary Threshold Shift (TTS)--TTS is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS, 2018). Based on data from cetacean TTS
measurements (Southall et al., 2007), a TTS of 6 dB is considered the
minimum TS clearly larger than any day-to-day or session-to-session
variation in a subject's normal hearing ability (Schlundt et al., 2000;
Finneran et al., 2000, 2002). As described in Finneran (2015), marine
mammal studies have shown the amount of TTS increases with cumulative
sound exposure level (SEL<INF>cum</INF>) in an accelerating fashion: At
low exposures with lower SEL<INF>cum,</INF> the amount of TTS is
typically small and the growth curves have shallow slopes. At exposures
with higher SEL<INF>cum</INF>, the growth curves become steeper and
approach linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in the Masking
section, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Many studies have examined noise-induced hearing loss in marine
mammals (see Finneran (2015) and Southall et al. (2019) for summaries).
TTS is the mildest form of hearing impairment that can occur during
exposure to sound (Kryter, 2013). While experiencing TTS, the hearing
threshold rises, and a sound must be at a higher level in order to be
heard. In terrestrial and marine mammals, TTS can last from minutes or
hours to days (in cases of strong TTS). In many cases, hearing
sensitivity recovers rapidly after exposure to the sound ends. For
cetaceans, published data on the onset of TTS are limited to captive
bottlenose dolphin (Tursiops truncatus), beluga whale, harbor porpoise,
and Yangtze finless porpoise (Neophocoena asiaeorientalis) (Southall et
al., 2019). For pinnipeds in water, measurements of TTS are limited to
harbor seals, elephant seals, bearded seals (Erignathus barbatus) and
California sea lions (Kastak et al., 1999, 2007; Kastelein et al.,
2019b, 2019c, 2021, 2022a, 2022b; Reichmuth et al., 2019; Sills et al.,
2020). TTS was not observed in spotted (Phoca largha) and ringed (Pusa
hispida) seals exposed to single airgun impulse sounds at levels
matching previous predictions of TTS onset (Reichmuth et al., 2016).
These studies examine hearing thresholds measured in marine mammals
before and after exposure to intense or long-duration sound exposures.
The difference between the pre-exposure and post-exposure thresholds
can be used to determine the amount of threshold shift at various post-
exposure times.
The amount and onset of TTS depends on the exposure frequency.
Sounds at low frequencies, well below the region of best sensitivity
for a species or hearing group, are less hazardous than those at higher
frequencies, near the region of best sensitivity (Finneran and
Schlundt, 2013). At low frequencies, onset-TTS exposure levels are
higher compared to those in the region of best sensitivity (i.e., a low
frequency noise would need to be louder to cause TTS onset when TTS
exposure level is higher), as shown for harbor porpoises and harbor
seals (Kastelein et al., 2019a, 2019c). Note that in general, harbor
seals and harbor porpoises have a lower TTS onset than other measured
pinniped or cetacean species (Finneran, 2015). In addition, TTS can
accumulate across multiple exposures, but the resulting TTS will be
less than the TTS from a single, continuous exposure with the same SEL
(Mooney et al., 2009; Finneran et al., 2010; Kastelein et al., 2014,
2015). This means that TTS predictions based on the total, cumulative
SEL will overestimate the amount of TTS from intermittent exposures,
such as sonars and impulsive sources. Nachtigall et al. (2018) describe
measurements of hearing sensitivity of multiple odontocete species
(bottlenose dolphin, harbor porpoise, beluga, and false killer whale
(Pseudorca crassidens)) when a relatively loud sound was preceded by a
warning sound. These captive animals were shown to reduce hearing
sensitivity when warned of an impending intense sound. Based on these
experimental observations of captive animals, the authors suggest that
wild animals may dampen their hearing during prolonged exposures or if
conditioned to anticipate intense sounds. Another study showed that
echolocating animals (including odontocetes) might have anatomical
specializations that might allow for conditioned hearing reduction and
filtering of low-frequency ambient noise, including increased stiffness
and control of middle ear structures and placement of inner ear
structures (Ketten et al., 2021). Data available on noise-induced
hearing loss for mysticetes are currently lacking (NMFS, 2018).
Additionally, the existing marine mammal TTS data come from a limited
number of individuals within these species.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals, and there is no PTS data for cetaceans, but such
relationships are assumed to be similar to those in humans and other
terrestrial mammals. PTS typically occurs at exposure levels at least
several decibels above that inducing mild TTS (e.g., a 40-dB threshold
shift approximates PTS onset (Kryter et al., 1966; Miller, 1974), while
a 6-dB threshold shift approximates TTS onset (Southall et al., 2007,
2019). Based on data from terrestrial mammals, a precautionary
assumption is that the PTS thresholds for impulsive sounds (such as
impact pile driving pulses as received close to the source) are at
least 6 dB higher than the TTS threshold on a peak-pressure basis and
PTS cumulative sound exposure level thresholds are 15 to 20 dB higher
than TTS cumulative sound exposure level thresholds (Southall et al.,
2007, 2019). Given the higher level of sound or longer exposure
duration necessary to cause PTS as compared with TTS, it is
considerably less likely that PTS could occur.
Activities for this project include impact and vibratory pile
driving and vibratory removal. There would likely be pauses in
activities producing the sound during each day. Given these pauses and
the fact that many marine mammals are likely moving through the project
areas and not remaining for extended periods of time, the potential for
TS declines.
Behavioral Harassment--Exposure to noise from pile driving also has
the potential to behaviorally disturb marine mammals. Generally
speaking, NMFS considers a behavioral disturbance that
[[Page 14800]]
rises to the level of harassment under the MMPA a non-minor response--
in other words, not every response qualifies as behavioral disturbance,
and for responses that do, those of a higher level, or accrued across a
longer duration, have the potential to affect foraging, reproduction,
or survival. Behavioral disturbance may include a variety of effects,
including subtle changes in behavior (e.g., minor or brief avoidance of
an area or changes in vocalizations), more conspicuous changes in
similar behavioral activities, and more sustained and/or potentially
severe reactions, such as displacement from or abandonment of high-
quality habitat. Behavioral responses may include changing durations of
surfacing and dives, changing direction and/or speed; reducing/
increasing vocal activities; changing/cessation of certain behavioral
activities (such as socializing or feeding); eliciting a visible
startle response or aggressive behavior (such as tail/fin slapping or
jaw clapping); avoidance of areas where sound sources are located.
Pinnipeds may increase their haul out time, possibly to avoid in-water
disturbance (Thorson and Reyff, 2006).
Behavioral responses to sound are highly variable and context-
specific and any reactions depend on numerous intrinsic and extrinsic
factors (e.g., species, state of maturity, experience, current
activity, reproductive state, auditory sensitivity, time of day), as
well as the interplay between factors (e.g., Richardson et al., 1995;
Wartzok et al., 2004; Southall et al., 2007, 2019; Weilgart, 2007;
Archer et al., 2010). Behavioral reactions can vary not only among
individuals but also within an individual, depending on previous
experience with a sound source, context, and numerous other factors
(Ellison et al., 2012), and can vary depending on characteristics
associated with the sound source (e.g., whether it is moving or
stationary, number of sources, distance from the source). In general,
pinnipeds seem more tolerant of, or at least habituate more quickly to,
potentially disturbing underwater sound than do cetaceans, and
generally seem to be less responsive to exposure to industrial sound
than most cetaceans. Please see Appendices B and C of Southall et al.
(2007) and Gomez et al. (2016) for reviews of studies involving marine
mammal behavioral responses to sound.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2004). Animals are most likely to habituate to
sounds that are predictable and unvarying. It is important to note that
habituation is appropriately considered as a ``progressive reduction in
response to stimuli that are perceived as neither aversive nor
beneficial,'' rather than as, more generally, moderation in response to
human disturbance (Bejder et al., 2009). The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure.
As noted above, behavioral state may affect the type of response.
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.,
1995; Wartzok et al., 2004; National Research Council (NRC), 2005).
Controlled experiments with captive marine mammals have showed
pronounced behavioral reactions, including avoidance of loud sound
sources (Ridgway et al., 1997; Finneran et al., 2003). Observed
responses of wild marine mammals to loud pulsed sound sources (e.g.,
seismic airguns) have been varied but often consist of avoidance
behavior or other behavioral changes (Richardson et al., 1995; Morton
and Symonds, 2002; Nowacek et al., 2007).
Available studies show wide variation in response to underwater
sound; therefore, it is difficult to predict specifically how any given
sound in a particular instance might affect marine mammals perceiving
the signal. If a marine mammal does react briefly to an underwater
sound by changing its behavior or moving a small distance, the impacts
of the change are unlikely to be significant to the individual, let
alone the stock or population. However, if a sound source displaces
marine mammals from an important feeding or breeding area for a
prolonged period, impacts on individuals and populations could be
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC,
2005). However, there are broad categories of potential response, which
we describe in greater detail here, that include alteration of dive
behavior, alteration of foraging behavior, effects to breathing,
interference with or alteration of vocalization, avoidance, and flight.
Changes in dive behavior can vary widely and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et
al., 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior
may reflect interruptions in biologically significant activities (e.g.,
foraging) or they may be of little biological significance. The impact
of an alteration to dive behavior resulting from an acoustic exposure
depends on what the animal is doing at the time of the exposure and the
type and magnitude of the response.
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. However, acoustic and movement bio-logging tools have been
used in some cases, to infer responses of feeding to anthropogenic
noise. For example, Blair et al. (2016) reported significant effects on
humpback whale foraging behavior in Stellwagen Bank in response to ship
noise including slower descent rates, and fewer side-rolling events per
dive with increasing ship nose. In addition, Wisniewska et al. (2018)
reported that tagged harbor porpoises demonstrated fewer prey capture
attempts when encountering occasional high-noise levels resulting from
vessel noise as well as more vigorous fluking, interrupted foraging,
and cessation of echolocation signals observed in response to some
high-noise vessel passes.
In response to playbacks of vibratory pile driving sounds, captive
bottlenose dolphins showed changes in target detection and number of
clicks used for a trained echolocation task (Branstetter et al., 2018).
Similarly, harbor porpoises trained to collect fish during playback of
impact pile driving sounds also showed potential changes in behavior
and task success, though individual differences were prevalent
(Kastelein et al., 2019d). As for other types of behavioral response,
the frequency, duration, and temporal pattern of signal presentation,
as well as differences in species sensitivity, are likely contributing
factors to differences in response in any given circumstance (e.g.,
Croll et al., 2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko
et al., 2007). A determination of whether foraging disruptions incur
fitness consequences would require information on or estimates of the
energetic requirements of the affected individuals and the
relationships among prey availability, foraging effort and success, and
the life history stage(s) of the animal.
Variations in respiration naturally vary with different behaviors
and alterations to breathing rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight
[[Page 14801]]
response or an alteration in diving. However, respiration rates in and
of themselves may be representative of annoyance or an acute stress
response. Various studies have shown that respiration rates may either
be unaffected or could increase, depending on the species and signal
characteristics, again highlighting the importance in understanding
species differences in the tolerance of underwater noise when
determining the potential for impacts resulting from anthropogenic
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et
al., 2007). For example, harbor porpoise' respiration rate increased in
response to pile driving sounds at and above a received broadband SPL
of 136 dB (zero-peak SPL: 151 dB (referenced to 1 micropascal (re 1
[mu]Pa)); SEL of a single strike: 127 dB re 1 [mu]Pa\2\-s) (Kastelein
et al., 2013).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
are known to change direction--deflecting from customary migratory
paths--in order to avoid noise from seismic surveys (Malme et al.,
1984). Avoidance may be short-term, with animals returning to the area
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996;
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006).
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996; Bowers et al., 2018). The result of a flight response
could range from brief, temporary exertion and displacement from the
area where the signal provokes flight to, in extreme cases, marine
mammal strandings (England et al., 2001). However, it should be noted
that response to a perceived predator does not necessarily invoke
flight (Ford and Reeves, 2008), and whether individuals are solitary or
in groups may influence the response.
Behavioral disturbance can also impact marine mammals in more
subtle ways. Increased vigilance may result in costs related to
diversion of focus and attention (i.e., when a response consists of
increased vigilance, it may come at the cost of decreased attention to
other critical behaviors such as foraging or resting). These effects
have generally not been demonstrated for marine mammals, but studies
involving fishes and terrestrial animals have shown that increased
vigilance may substantially reduce feeding rates (e.g., Beauchamp and
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In
addition, chronic disturbance can cause population declines through
reduction of fitness (e.g., decline in body condition) and subsequent
reduction in reproductive success, survival, or both (e.g., Harrington
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However,
Ridgway et al. (2006) reported that increased vigilance in bottlenose
dolphins exposed to sound over a 5-day period did not cause any sleep
deprivation or stress effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than 1 day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive (i.e., meaningful) behavioral reactions and multi-day
anthropogenic activities. For example, just because an activity lasts
for multiple days does not necessarily mean that individual animals are
either exposed to activity-related stressors for multiple days or,
further, exposed in a manner resulting in sustained multi-day
substantive behavioral responses.
Stress Responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle, 1950;
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha,
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
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
[[Page 14802]]
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.
Auditory Masking--Since many marine mammals rely on sound to find
prey, moderate social interactions, and facilitate mating (Tyack,
2008), noise from anthropogenic sound sources can interfere with these
functions, but only if the noise spectrum overlaps with the hearing
sensitivity of the receiving marine mammal (Southall et al., 2007;
Clark et al., 2009; Hatch et al., 2012). Chronic exposure to excessive,
though not high-intensity, noise could cause masking at particular
frequencies for marine mammals that utilize sound for vital biological
functions (Clark et al., 2009). Acoustic masking is when other noises
such as from human sources interfere 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; Erbe et al., 2016). Therefore, under certain
circumstances, marine mammals whose acoustical sensors or environment
are being severely masked could also be impaired from maximizing their
performance fitness in survival and reproduction. 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 (Hotchkin and
Parks, 2013).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003) or vocalizations (Foote et al., 2004),
respectively, while North Atlantic right whales (Eubalaena glacialis)
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007). Fin whales have also been documented
lowering the bandwidth, peak frequency, and center frequency of their
vocalizations under increased levels of background noise from large
vessels (Castellote et al., 2012). Other alterations to communication
signals have also been observed. For example, gray whales, in response
to playback experiments exposing them to vessel noise, have been
observed increasing their vocalization rate and producing louder
signals at times of increased outboard engine noise (Dahlheim and
Castellote, 2016). Alternatively, animals may cease sound production
during production of aversive signals (Bowles et al., 1994).
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is human-made, it may be considered
harassment when disrupting or altering critical behaviors. It is
important to distinguish TTS and PTS, which persist after the sound
exposure, from masking, which occurs during the sound exposure. Because
masking (without resulting in TS) is not associated with abnormal
physiological function, it is not considered a physiological effect,
but rather a potential behavioral effect (though not necessarily one
that would be associated with harassment).
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009) and may result in energetic or other costs as
animals change their vocalization behavior (e.g., Miller et al., 2000;
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2010; Holt
et al., 2009). Masking can be reduced in situations where the signal
and noise come from different directions (Richardson et al., 1995),
through amplitude modulation of the signal, or through other
compensatory behaviors (Hotchkin and Parks, 2013). Masking can be
tested directly in captive species (e.g., Erbe, 2008), but in wild
populations it must be either modeled or inferred from evidence of
masking compensation. There are few studies addressing real-world
masking sounds likely to be experienced by marine mammals in the wild
(e.g., Branstetter et al., 2013).
Marine mammals at or near the proposed ARRC project site may be
exposed to anthropogenic noise which may be a source of masking.
Vocalization changes may result from a need to compete with an increase
in background noise and include increasing the source level, modifying
the frequency, increasing the call repetition rate of vocalizations, or
ceasing to vocalize in the presence of increased noise (Hotchkin and
Parks, 2013). For example, in response to loud noise, beluga whales may
shift the frequency of their echolocation clicks to prevent masking by
anthropogenic noise (Tyack, 2000; Eickmeier and Vallarta, 2022).
Masking occurs in the frequency band or bands that animals utilize
and is more likely to occur in the presence of broadband, relatively
continuous noise sources such as vibratory pile driving. Energy
distribution of pile driving covers a broad frequency spectrum, and
sound from pile driving would be within the audible range of pinnipeds
and cetaceans present in the proposed action area. While some
construction during the ARRC's activities may mask some acoustic
signals that are relevant to the daily behavior of marine mammals, the
short-term duration and limited areas affected make it very unlikely
that the fitness of individual marine mammals would be impacted.
Airborne Acoustic Effects--Pinnipeds that occur near the project
site could be exposed to airborne sounds associated with construction
activities that have the potential to cause behavioral harassment,
depending on their distance from these activities. Airborne noise would
primarily be an issue for pinnipeds that are swimming or hauled out
near the project site within the range of noise levels elevated above
airborne acoustic harassment criteria. According to the ARRC, pinnipeds
have historically been observed hauling out on the sediment groin near
the Freight Dock in 1999. While more recent information is not
available, it is possible that pinnipeds could temporarily haul out in
this area during the project. There is also a possibility that an
animal could surface in-water, but with head out, within the area in
which airborne sound exceeds relevant thresholds and thereby be exposed
to levels of airborne sound that we
[[Page 14803]]
associate with harassment. Any such occurrence on days with in-water
pile driving activities would likely be accounted for in our estimation
of incidental take from underwater sound. On days when pile driving is
occurring only on land immediately adjacent to the Freight Dock
authorization of incidental take resulting from airborne sound for
pinnipeds is warranted due to the potential for pinnipeds to be exposed
while hauled out on the sediment groin or surfacing with head out of
the water. Cetaceans are not expected to be exposed to airborne sounds
that would result in harassment as defined under the MMPA.
Marine Mammal Habitat Effects
The project would occur near an active marine commercial and
industrial area. Construction activities at the Seward Freight Dock
could have localized, temporary impacts on marine mammal habitat and
their prey by increasing in-water SPLs and slightly decreasing water
quality. Increased noise levels may affect acoustic habitat (see
Auditory Masking discussion above) and adversely affect marine mammal
prey in the vicinity of the project area (see discussion below). During
in-water vibratory and impact pile driving, elevated levels of
underwater noise would ensonify a portion of Resurrection Bay, where
both fish and some mammals occur and could affect foraging success.
Construction activities are of short duration and would likely have
temporary impacts on marine mammal habitat through increases in
underwater and airborne sound. These sounds would not be detectable at
the nearest known official sea lion and seal haulouts, which are beyond
the maximum distance of predicted in-air acoustical disturbance.
Water Quality--Temporary and localized reduction in water quality
would occur as a result of in-water construction activities. Most of
this effect would occur during the installation and removal of piles
when bottom sediments are disturbed. The installation and removal of
piles would disturb bottom sediments and may cause a temporary increase
in suspended sediment in the project area. During pile removal,
sediment attached to the pile moves vertically through the water column
until gravitational forces cause it to slough off under its own weight.
The small resulting sediment plume is expected to settle out of the
water column within a few hours. Studies of the effects of turbid water
on fish (marine mammal prey) suggest that concentrations of suspended
sediment can reach thousands of milligrams per liter before an acute
toxic reaction is expected (Burton, 1993).
Effects to turbidity and sedimentation are expected to be short-
term, minor, and localized. Suspended sediments in the water column
should dissipate and quickly return to background levels in all
construction scenarios. Turbidity within the water column has the
potential to reduce the level of oxygen in the water and irritate the
gills of prey fish species in the proposed project area. However,
turbidity plumes associated with the project would be temporary and
localized, and fish in the proposed project area would be able to move
away from and avoid the areas where plumes may occur. Therefore, it is
expected that the impacts on prey fish species from turbidity, and
therefore on marine mammals, would be minimal and temporary. In
general, the area likely impacted by the proposed construction
activities is relatively small compared to the available marine mammal
habitat in the Gulf of Alaska, and does not include any areas of
particular importance.
In-Water Construction Effects on Potential Prey--Sound may affect
marine mammals through impacts on the abundance, behavior, or
distribution of prey species (e.g., crustaceans, cephalopods, fish,
zooplankton). Marine mammal prey varies by species, season, and
location and, for some, is not well documented. Here, we describe
studies regarding the effects of noise on known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Additional studies
have documented effects of pile driving on fish, although several are
based on studies in support of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings,
2009). Several studies have demonstrated that impulse sounds might
affect the distribution and behavior of some fishes, potentially
impacting foraging opportunities or increasing energetic costs (e.g.,
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al.,
1992; Santulli et al., 1999; Paxton et al., 2017). However, some
studies have shown no or slight reaction to impulse sounds (e.g., Pena
et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Cott
et al., 2012). More commonly, though, the impacts of noise on fish are
temporary.
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The greatest potential impact to fishes during construction would
occur during impact pile installation of 24-in steel pipe piles, which
is estimated to occur on up to 28 days for a maximum of 1,230 strikes
per day. In-water construction activities would only occur during
daylight hours, allowing fish to forage and transit the project area in
the evening. Vibratory pile driving would possibly elicit behavioral
reactions from fishes such as temporary avoidance of the area but is
unlikely to cause injuries to fishes or have persistent effects on
local fish populations. Construction also would have minimal permanent
and temporary impacts on benthic invertebrate species, a marine mammal
prey source. In addition, it should be
[[Page 14804]]
noted that the area in question is low-quality habitat since it is
already highly developed and experiences a high level of anthropogenic
noise from normal operations and other vessel traffic. In general, any
negative impacts on marine mammal prey species are expected to be minor
and temporary.
Fish populations in the proposed project area that serve as marine
mammal prey could be temporarily affected by noise from pile
installation and removal. The frequency range in which fishes generally
perceive underwater sounds is 50 to 2,000 Hz, with peak sensitivities
below 800 Hz (Popper and Hastings, 2009). Fish behavior or distribution
may change, especially with strong and/or intermittent sounds that
could harm fishes. High underwater SPLs have been documented to alter
behavior, cause hearing loss, and injure or kill individual fish by
causing serious internal injury (Hastings and Popper, 2005).
The most likely impact to fish from pile driving activities in the
project area would be temporary behavioral avoidance of the area. The
duration of fish avoidance of an area after pile driving stops is
unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated. In general, impacts to marine mammal prey
species are expected to be minor and temporary due to the expected
short daily duration of individual pile driving events.
In-Water Construction Effects on Potential Foraging Habitat--The
area likely impacted by the project is relatively small compared to the
available habitat in the Gulf of Alaska and does not include any
biologically important areas (BIAs) or ESA-designated critical habitat.
The total area affected by pile installation and removal and the new
footprint is small compared to the vast foraging area available to
marine mammals in the area. Pile driving and removal at the project
site would not obstruct long-term movements or migration of marine
mammals.
Avoidance by potential prey (i.e., fish) of the immediate area due
to the temporary loss of this foraging habitat is also possible. The
duration of fish and marine mammal avoidance of this area after pile
driving stops is unknown, but a rapid return to normal recruitment,
distribution, and behavior is anticipated. Any behavioral avoidance by
fish or marine mammals of the disturbed area would still leave
significantly large areas of fish and marine mammal foraging habitat in
the nearby vicinity.
In summary, given the short daily duration of sound associated with
individual pile driving events and the relatively small areas being
affected, pile driving activities associated with the proposed action
are not likely to have a permanent adverse effect on any fish habitat,
or populations of fish species. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large areas of fish and
marine mammal foraging habitat in the nearby vicinity. Thus, we
conclude that impacts of the specified activity are not likely to have
more than short-term adverse effects on any prey habitat or populations
of prey species. Further, any impacts to marine mammal habitat are not
expected to result in significant or long-term consequences for
individual marine mammals, or to contribute to adverse impacts on their
populations.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization through the IHA, which will inform NMFS'
consideration of ``small numbers,'' the negligible impact
determinations, and impacts on subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic source (i.e., pile driving) has the potential to result
in disruption of behavioral patterns for individual marine mammals.
There is also some potential for AUD INJ (Level A harassment) to
result, primarily for very high frequency species and phocids because
predicted AUD INJ zones are larger than for high-frequency species and
otariids. AUD INJ is unlikely to occur for high-frequency species and
otariids. The proposed mitigation and monitoring measures are expected
to minimize the severity of the taking to the extent practicable. As
described previously, no serious injury or mortality is anticipated or
proposed to be authorized for this activity. Below we describe how the
proposed take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic criteria above which NMFS believes the best
available science indicates marine mammals will likely be behaviorally
harassed or incur some degree of AUD INJ; (2) the area or volume of
water that will be ensonified above these levels in a day; (3) the
density or occurrence of marine mammals within these ensonified areas;
and, (4) the number of days of activities. We note that while these
factors can contribute to a basic calculation to provide an initial
prediction of potential takes, additional information that can
qualitatively inform take estimates is also sometimes available (e.g.,
previous monitoring results or average group size). Below, we describe
the factors considered here in more detail and present the proposed
take estimates.
Acoustic Criteria
NMFS recommends the use of acoustic criteria that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur AUD INJ of some degree (equated to
Level A harassment). We note that the criteria for AUD INJ, as well as
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 received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater
[[Page 14805]]
anthropogenic noise above root-mean-squared pressure received levels
(RMS SPL) of 120 dB 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. For in-air sounds, NMFS predicts that harbor
seals exposed above received levels of 90 dB re 20 [mu]Pa (rms) will be
behaviorally harassed. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by TTS as, in most cases, the likelihood of
TTS occurs at distances from the source less than those at which
behavioral harassment is likely. TTS of a sufficient degree can
manifest as behavioral harassment, as reduced hearing sensitivity and
the potential reduced opportunities to detect important signals
(conspecific communication, predators, prey) may result in changes in
behavior patterns that would not otherwise occur.
ARRC's proposed activity includes the use of continuous (vibratory
pile driving) and impulsive (impact pile driving) sources, and
therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are
applicable.
Level A Harassment--NMFS' Updated Technical Guidance for Assessing
the Effects of Anthropogenic Sound on Marine Mammal Hearing (Version
3.0; Updated Technical Guidance, 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).
ARRC's proposed activity includes the use of impulsive (impact pile
driving) and non-impulsive (vibratory pile driving) sources.
The 2024 Updated Technical Guidance criteria include both updated
thresholds and updated weighting functions for each hearing group. The
thresholds are provided in the table below. The references, analysis,
and methodology used in the development of 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 [mu]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1 [mu]Pa\2\s. In this table, criteria are abbreviated to be
more reflective of International Organization for Standardization standards (ISO 2017; ISO 2020). The
subscript ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within
the generalized hearing range of marine mammals underwater (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 a multitude of ways
(i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for action proponents
to indicate the conditions under which these criteria will be exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected via sound generated by the
primary components of the project (i.e., pile driving and removal).
The project includes vibratory pile installation and removal, and
impact pile driving. Source levels for these activities are based on
reviews of measurements of the same or similar types and dimensions of
piles available in the literature. Source levels for each pile size are
presented in tables 5 and 6. Source levels for vibratory installation
and removal of piles of the same diameter are assumed to be the same.
Table 5--Estimates of Mean Underwater Sound Levels * Generated During In-Water Vibratory and Impact Pile Installation and Vibratory Pile Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
dB RMS (dB dB peak (dB dB SEL (dB
Method Pile size and type re 1 uPa re 1 uPa re 1 uPa Reference
RMS) RMS) RMS)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory install and removal........... 24-in steel pile.......... 163 181 153 NMFS 2023 Calculation.
Vibratory Install....................... Sheet pile pair........... 160.7 ........... 161.1 Caltrans 2015.
Vibratory Install....................... H-pile.................... 150 ........... 147 Caltrans 2015.
Vibratory Install....................... 30-in steel pile.......... 167 179 153 NMFS 2023 Calculation.
Impact install.......................... 30-in steel pile.......... 190 210 177 Caltrans 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: dB peak = peak sound level; rms = root mean square; SEL = sound exposure level.
* All sound levels are referenced at 10 m.
[[Page 14806]]
Table 6--Estimated In-Air Proxy Source Levels for Upland Vibrocompaction, Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
Source level
Method Pile size and type (dB) Reference
----------------------------------------------------------------------------------------------------------------
Vibratory install and removal..... All piles............ 103 NMFS 2023 Calculation.
----------------------------------------------------------------------------------------------------------------
TL is the decrease in acoustic intensity as an acoustic pressure
wave propagates out from a source. TL parameters vary with frequency,
temperature, sea conditions, current, source and receiver depth, water
depth, water chemistry, and bottom composition and topography. The
general formula for underwater TL is:
TL = B x Log10 (R<INF>1</INF>/R<INF>2</INF>),
Where:
TL = transmission loss in dB
B = transmission loss coefficient
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement
Absent site-specific acoustical monitoring with differing measured
TL, a practical spreading value of 15 is used as the TL coefficient in
the above formula. Site-specific TL data for Resurrection Bay are not
available; therefore, the default coefficient of 15 is used to
determine the distances to the Level A harassment and Level B
harassment thresholds.
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the 2024 Updated Technical Guidance that
can be used to relatively simply predict an isopleth distance for use
in conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources [such as pile driving], 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 can be found above in tables 1, 5, and 6, and the resulting
estimated isopleths, are reported below.
Table 7--Level A and Level B Harassment Isopleths for Pile Driving Activities
----------------------------------------------------------------------------------------------------------------
Distances to Level A and Level B thresholds (m)
Method Pile size and -----------------------------------------------------------------
type LF HF VHF Phocids Otariid Level B
----------------------------------------------------------------------------------------------------------------
In-water Removal and Install
----------------------------------------------------------------------------------------------------------------
Vibratory install and removal 24-in steel 41.4 15.9 33.8 53.3 17.9 7,356.4
pile.
Vibratory Install............ Sheet pile pair 40.9 15.7 33.4 52.6 17.7 5,168.2
Vibratory Install............ H-pile......... 2.7 1 2.2 30.5 1.2 1,000
Vibratory Install (Fender)... 30-in steel 58.4 22.4 47.7 75.1 25.3 13,593.6
pile.
Vibratory Install (Dolphin).. 30-in steel 36.8 14.1 30 47.3 15.9 13,593.6
pile.
Impact install............... 30-in steel 930.4 118.7 1,439.9 826.6 308.1 1,000
pile.
----------------------------------------------------------------------------------------------------------------
Uplands Removal and Install
----------------------------------------------------------------------------------------------------------------
Vibratory install and removal All piles...... Na Na Na Na Na * 67
----------------------------------------------------------------------------------------------------------------
* Only applicable to Harbor seals. No in-air take of any otariids is anticipated, so we have only included the
range for phocids in this table.
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform the take calculations.
The ARRC calculated a monthly occurrence estimate based on
literature and communication with locals in the Seward area. They then
multiplied that monthly occurrence by the estimated days of work in
that month. After review of their estimates, NMFS believed some of the
estimates to be inconsistent with the cited literature and local
communications. Following careful review of the analysis and literature
presented by the ARRC in its application, including marine mammal
occurrence data and estimates, NMFS has preliminarily determined that
different occurrence calculations for some species based on seasonality
(peak vs off-peak) rather than monthly, represent the best available
scientific information for marine mammal abundance in the action area
(table 8). This change from what ARRC proposed was done in consultation
with the NMFS Alaska Region and other active Seward actions. Calculated
takes are still based on ARRC's method.
As described above, the estimated number of days of in-water pile
driving is 155 and the number of days with upland pile driving is 106.
However, for take incidental to the upland construction, only days
where there is upland only construction (64 days) was used in the
calculation. On days where there is both in water and upland
construction we assume harbor seals would be taken in the water prior
to hauling out. Take incidental to upland construction is only expected
for harbor seals. We do not expect in-air take of any Otariids and
therefor have not included them in table 7 above.
There is also some potential for take by Level A harassment of
harbor seal, Dall's porpoise, and harbor porpoise during impact pile
driving due to the largest zones of each species being greater than the
shutdown zones and/or because of the cryptic nature and assumed lower
detectability of these species. We calculated Level A take using the
same method as Level B, using
[[Page 14807]]
only days of work where impact driving would occur.
Table 8--Species Occurrence Estimated
------------------------------------------------------------------------
Species Abundance estimate
------------------------------------------------------------------------
Gray whale............................. 1 group of 1 over the project.
Fin whale.............................. 1 group of 2 over the project.
Humpback whale......................... Peak: 1/day; Off-peak: 1 every
other day.
Killer whale........................... Peak: 7/week; Off-peak: 5/week.
Pacific white sided dolphin............ 2/month (spring/summer); 3/
month (fall/winter).
Dall's porpoise........................ 5 every other day.
Harbor porpoise........................ 1/day.
Harbor seal............................ 12/day.
Steller sea lion....................... Peak: 8/day; Off-peak: 2/day.
Northern elephant seal................. 1/month.
California sea lion.................... 1/month.
------------------------------------------------------------------------
Table 9--Proposed Take by Stock, Harassment Type, and as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
Proposed authorized take
-------------------------- Proposed take as
Species Stock Level A Level B percentage of
harassment harassment stock
----------------------------------------------------------------------------------------------------------------
Gray whale.............................. Eastern North Pacific..... 0 1 <0.1
Fin whale............................... Northeast Pacific......... 0 2 \1\ 0.1
Humpback whale \2\...................... Hawaii.................... 0 104 0.9
Mexico.................... 0 13 \3\ 0.1
Western North Pacific..... 0 1 0.1
Killer whale \4\........................ AT1 Transient............. 0 2 28.6
Gulf, Aleutian, Bering 0 3 0.5
Transient.
ENP Alaska Resident....... 0 128 6.7
Pacific white sided dolphin............. North Pacific............. 0 17 0.1
Dall's porpoise......................... Alaska.................... 13 388 \5\ UND
Harbor porpoise......................... Gulf of Alaska............ 5 155 <0.1
Harbor seal............................. Prince William Sound...... 60 \6\ 2,116 4.9
Steller sea lion........................ Western United States..... 0 790 1.6
Northern elephant seal.................. California Breeding....... 0 12 <0.1
California sea lion..................... United States............. 0 12 <0.1
----------------------------------------------------------------------------------------------------------------
\1\ Based on 2,554 animals discussed in SARs, although it's noted that this is likely an underestimate.
\2\ Based on proportion of each distinct population segment (DPS) being in resurrection bay: 89 percent Hawaii,
10 percent Mexico, and 1 percent Western North Pacific (NMFS, 2021).
\3\ Based on 918 animals discussed in SARs, derived from Wade, 2021.
\4\ Based on a proportion from acoustic monitoring of stocks in Resurrection Bay: 95.7 percent ENP residents,
2.7 percent Gulf/Aleutian/Bering transients, and 1.6 percent AT1 transients (Yurk et al., 2010).
\5\ NMFS does not have an official abundance estimate for this stock, and the minimum population estimate is
considered to be unknown (Young et al., 2023). See Small Numbers for additional discussion.
\6\ 1,860 in-water takes and 256 in-air takes. In-air takes based on upland construction only days.
Proposed Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses. NMFS regulations require applicants for incidental
take authorizations to include information about the availability and
feasibility (economic and technological) of equipment, methods, and
manner of conducting the activity or other means of effecting the least
practicable adverse impact upon the affected species or stocks, and
their habitat (50 CFR 216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat, as
well as subsistence uses. This considers the nature of the potential
adverse impact being mitigated (likelihood, scope, range). It further
considers the likelihood that the measure will be effective if
implemented (probability of accomplishing the mitigating result if
implemented as planned), the likelihood of effective implementation
(probability implemented as planned); and,
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, and impact on
operations.
ARRC must ensure that construction supervisors and crews, the
monitoring team, and relevant ARRC staff are trained prior to the start
of all pile driving activity, so that responsibilities, communication
procedures, monitoring protocols, and operational procedures are
clearly understood. New personnel joining during the project must be
trained prior to commencing work.
[[Page 14808]]
Pre- and Post-Activity Monitoring
<bullet> Monitoring must take place from 30 minutes prior to
initiation of pile driving activity (i.e., pre-clearance monitoring)
through 30 minutes post-completion of pile driving activity; and,
<bullet> Pre-start clearance monitoring must be conducted during
periods of visibility sufficient for the lead protected species
observer (PSO) to determine that the shutdown zones indicated in table
10 are clear of marine mammals. Pile driving may commence following 30
minutes of observation when the determination is made that the shutdown
zones are clear of marine mammals.
Soft Start
ARRC must use soft start techniques when impact pile driving. Soft
start requires contractors to provide an initial set of three strikes
at reduced energy, followed by a 30-second waiting period, then two
subsequent reduced-energy strike sets. A soft start must be implemented
at the start of each day's impact pile driving and at any time
following cessation of impact pile driving for a period of 30 minutes
or longer.
Shutdown Zones
ARRC will establish shutdown zones for all pile driving activities.
The purpose of a shutdown zone is generally to define an area within
which shutdown of the activity will occur upon sighting of a marine
mammal (or in anticipation of an animal entering the defined area).
If a marine mammal is observed entering or within the shutdown
zones indicated in table 10, pile driving must be delayed or halted.
For in-water heavy machinery activities other than pile driving, if a
marine mammal comes within 10 m, work must stop and vessels must reduce
speed to the minimum level required to maintain steerage and safe
working conditions. A 10 m shutdown zone will also serve to protect
marine mammals from physical interactions with project vessels during
pile driving and other construction activities, such as barge
positioning or drilling. If an activity is delayed or halted due to the
presence of a marine mammal, the activity may not commence or resume
until either the animal has voluntarily exited and been visually
confirmed beyond the shutdown zone indicated in table 10, or 15 minutes
have passed without re-detection of the animal. Construction activities
must be halted upon observation of a species for which incidental take
is not authorized or a species for which incidental take has been
authorized but the authorized number of takes has been met entering or
within the harassment zone.
All marine mammals will be monitored in the Level B harassment
zones and throughout the area as far as visual monitoring can take
place. If a marine mammal enters the Level B harassment zone, in-water
activities will continue and the animal's presence within the estimated
harassment zone will be documented.
ARRC will also establish shutdown zones for all marine mammals for
which take has not been authorized or for which incidental take has
been authorized but the authorized number of takes has been met. These
zones are equivalent to the Level B harassment zones for each activity.
If a marine mammal species for which take is not authorized by this IHA
enters the shutdown zone, all in-water activities will cease until the
animal leaves the zone or has not been observed for at least 15
minutes, and ARRC will notify NMFS about the species and precautions
taken. Pile driving will proceed if the non-IHA species is observed to
leave the Level B harassment zone or if 15 minutes have passed since
the last observation.
If shutdown and/or clearance procedures will result in an imminent
safety concern, as determined by ARRC or its designated officials, the
in-water activity will be allowed to continue until the safety concern
has been addressed, and the animal will be continuously monitored.
Table 10--Shutdown Zones and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
Minimum shutdown zone (m)
------------------------------------------------------------ Level B
Activity LF HF VHF harassment
cetaceans cetaceans cetaceans Phocid Otariid zone (m)
----------------------------------------------------------------------------------------------------------------
24-in vibratory removal and install.... 45 20 35 55 20 7,360
Sheet pile vibratory install........... 45 20 35 55 20 5,170
H-pile vibratory install............... 10 10 10 10 10 1,000
30-in vibratory install (fender)....... 60 25 50 80 30 13,595
30-in vibratory install (dolphin)...... 40 15 30 50 20 13,595
Impact Installation.................... 935 120 300 300 310 1,000
Upland vibratory pile install and Na Na Na Na Na \1\ 70
removal...............................
----------------------------------------------------------------------------------------------------------------
\1\ For Phocids only.
Protected Species Observers
The placement of PSOs during all construction activities (described
in the Monitoring and Reporting section) will ensure that the entire
shutdown zone is visible. Should environmental conditions deteriorate
such that the entire shutdown zone will not be visible (e.g., fog,
heavy rain), pile driving will be delayed until the PSO is confident
marine mammals within the shutdown zone could be detected.
The ARRC must employ PSOs and establish monitoring locations as
described in the marine mammal monitoring plan and the IHA. PSOs will
monitor the full shutdown zones and the Level B harassment zones to the
extent practicable. Monitoring zones provide utility for observing by
establishing monitoring protocols for areas adjacent to the shutdown
zones. Monitoring zones enable observers to be aware of and communicate
the presence of marine mammals in the project areas outside the
shutdown zones and thus prepare for a potential cessation of activity
should the animal enter the shutdown zone.
Based on our evaluation of ARRC's measures, as well as other
measures considered by NMFS, NMFS has determined that the mitigation
measures provide the means effecting the least practicable impact on
the affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance. Bubble curtains were considered as a mitigation measure
for the proposed action, however were ultimately deemed impractical as
the majority of piles proposed are sheet and batter piles which cannot
be fully
[[Page 14809]]
encompassed by the bubble curtain and reduce the effectiveness of the
mitigation measure.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring must be conducted in accordance with the
conditions in this section and the IHA. Marine mammal monitoring during
pile driving activities must be conducted by PSOs meeting the following
requirements:
<bullet> PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods;
<bullet> At least one PSO must have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization;
<bullet> Other PSOs may substitute relevant experience, education
(degree in biological science or related field), or training for prior
experience performing the duties of a PSO during construction activity
pursuant to a NMFS-issued incidental take authorization; and,
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator will be designated. The lead
observer will be required to have prior experience performing the
duties of a PSO during construction activities pursuant to a NMFS-
issued incidental take authorization.
PSOs must have the following additional qualifications:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and,
<bullet> Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
ARRC must assign a minimum of three PSOs to monitor during pile
driving. One PSO must be stationed at the pile driving site, and the
other PSOs must be stationed at the best practicable location for
monitoring the Level A and Level B harassment zones (see Marine Mammal
Monitoring Plan). All PSOs will have access to high-quality binoculars,
range finders to monitor distances, and a compass to record bearing to
animals as well as radios or cells phones for maintaining contact with
work crews.
Monitoring will be conducted 30 minutes before, during, and 30
minutes after all in water construction activities. In addition, PSOs
will record all incidents of marine mammal occurrence, regardless of
distance from activity, and will document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving
activities include the time to install or remove a single pile or
series of piles, as long as the time elapsed between uses of the pile
driving equipment is no more than 30 minutes.
ARRC shall conduct briefings between construction supervisors and
crews, PSOs, ARRC staff prior to the start of all pile driving
activities and when new personnel join the work. These briefings must
explain responsibilities, communication procedures, marine mammal
monitoring protocol, and operational procedures.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities, or 60 days prior to a requested date of issuance from any
future IHAs for projects at the same location, whichever comes first.
The report will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated electronic
PSO data sheets. Specifically, the report must include:
<bullet> Dates and times (begin 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) and the total equipment
duration for vibratory removal for each pile or total number of strikes
for each pile (impact driving);
<bullet> PSO locations during marine mammal monitoring;
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
<bullet> Upon observation of a marine mammal, the following
information: (1) Name of PSO who sighted the animal(s) and PSO location
and activity at the time of sighting; (2) Time of sighting; (3)
Identification of the animal(s) (e.g., genus/species, lowest possible
[[Page 14810]]
taxonomic level, or unidentifiable), PSO confidence in identification,
and the composition of the group if there is a mix of species; (4)
Distance and bearing of each marine mammal observed relative to the
pile being driven for each sightings (if pile driving was occurring at
time of sighting); (5) Estimated number of animals (min/max/best
estimate); (6) Estimated number of animals by cohort (adults,
juveniles, neonates, group composition, sex class, etc.); (7) Animal's
closest point of approach and estimated time spent within the
harassment zone; (8) Description of any marine mammal behavioral
observations (e.g., observed behaviors such as feeding or traveling),
including an assessment of behavioral responses thought to have
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching);
<bullet> Number of marine mammals detected within the harassment
zones and shutdown zones; by species; and,
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensured, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the ARRC must immediately
cease the specified activities and report the incident to the Office of
Protected Resources (OPR) (<a href="/cdn-cgi/l/email-protection#bdedef93f4e9ed93f0d2d3d4c9d2cfd4d3daefd8cdd2cfc9cefdd3d2dcdc93dad2cb"><span class="__cf_email__" data-cfemail="bdedef93f4e9ed93f0d2d3d4c9d2cfd4d3daefd8cdd2cfc9cefdd3d2dcdc93dad2cb">[email protected]</span></a>), NMFS and
to the Alaska Regional Stranding Coordinator as soon as feasible. If
the death or injury was clearly caused by the specified activity, ARRC
must immediately cease the specified activities until NMFS is able to
review the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of the IHA. The ARRC must not resume their activities until notified by
NMFS. 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.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
To avoid repetition, the majority of our analysis applies to all
the species listed in table 2, given that many of the anticipated
effects of this project on different marine mammal stocks are expected
to be relatively similar in nature. Where there are meaningful
differences between species or stocks, or groups of species, in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, they are described independently below.
Pile driving activities associated with the ARRC construction
project has the potential to disturb or displace marine mammals.
Specifically, the project activities may result in take, in the form of
Level A and Level B harassment, from underwater and in-air sounds
generated from pile driving and removal. Potential takes could occur if
individuals are present in the ensonified zone when these activities
are underway.
The takes by Level B harassment would be due to potential
behavioral disturbance and TTS. Takes by Level A harassment would be
due to auditory injury. No serious injury or mortality is expected,
even in the absence of required mitigation measures, given the nature
of the activities. The potential for harassment will be further
minimized through the construction method and the implementation of the
planned mitigation measures (see Mitigation section).
Take by Level A harassment is authorized for harbor seals, Dall's
porpoise, and harbor porpoise to account for the possibility that an
animal could enter a Level A harassment zone prior to detection, and
remain within that zone for a duration long enough to incur auditory
injury before being observed and the ARRC shutting down pile driving
activity. The only activity we expect Level A harassment to occur from
would be impact pile driving. Given the short duration to impact drive
each pile and breaks between pile installations (to reset equipment and
move piles into place), an animal will have to remain within the area
estimated to be ensonified above the Level A harassment threshold for
multiple hours. This is highly unlikely given marine mammal movement in
the area. The number of takes by Level A harassment authorized is very
low for all marine mammal species. Any take by Level A harassment is
expected to arise from, at most, a small degree of auditory injury,
i.e., minor degradation (likely only a few dB) of hearing capabilities
within regions of hearing that align most completely with the energy
produced by vibratory and impact pile driving (i.e., the low-frequency
region below 2 kHz), not severe hearing impairment or impairment within
the ranges of greatest hearing sensitivity. Animals will need to be
exposed to higher levels and/or longer duration than are expected to
occur here in order to incur any more than a small degree of auditory
injury. Due to the small degree anticipated, any auditory injury
incurred will not be expected to affect the reproductive
[[Page 14811]]
success or survival of any individuals, much less result in adverse
impacts on the species or stock.
Additionally, some subset of the individuals that are behaviorally
harassed could also simultaneously incur some small degree of TTS for a
short duration of time. However, since the hearing sensitivity of
individuals that incur TTS is expected to recover completely within
minutes to hours, it is unlikely that the brief hearing impairment will
affect the individual's long-term ability to forage and communicate
with conspecifics, and will therefore not likely impact reproduction or
survival of any individual marine mammal, let alone adversely affect
rates of recruitment or survival of the species or stock.
Behavioral responses of marine mammals to pile driving in Seward
are expected to be mild, short term, and temporary. Marine mammals
within the Level B harassment zones may not show any visual cues they
are disturbed by activities or they could become alert, avoid the area,
leave the area, or display other mild responses that are not
observable, such as changes in vocalization patterns. Given that pile
driving will occur for only a portion of the project's duration, any
harassment will be temporary. Additionally, many of the species present
in region will only be present temporarily based on seasonal patterns
or during transit between other habitats. These temporarily present
species will be exposed to even smaller periods of noise-generating
activity, further decreasing the impacts.
Any impacts on marine mammal prey that will occur during ARRC's
planned activity will have, at most, short-term effects on foraging of
individual marine mammals, and likely no effect on the populations of
marine mammals as a whole. 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 effect on annual rates of
recruitment or survival.
For all species and stocks, take will occur within a limited,
confined area (adjacent to the project site) of the stock's range, and,
there are no known BIAs near the project area that will be impacted by
ARRC's activities. While harbor seal is the species most likely to
occur within the immediate project area, the nearest official haulout
is outside of the ensonified areas. There is a possible haulout site
for harbor seals in the project area on the sediment groin, although
the only documentation of this sighting is from 1999. There are no
official haulouts in the immediate project vicinity; the next closest
haulout is 14 km away. There are no Steller sea lion haulouts in the
project area. The closest haulout is 26 km from the project area.
In addition, it is unlikely that minor noise effects in a small,
localized area of habitat will have any effect on the reproduction or
survival of any individuals, much less the stocks' annual rates of
recruitment or survival. 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 impact rates of
recruitment or survival and would therefore not result in population-
level impacts.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect any of the species
or stocks through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Take by Level A harassment is authorized for harbor seal,
Dall's porpoise and harbor porpoise only and would be very small
amounts and of a low degree;
<bullet> For all species and stocks, Seward is a very small and
peripheral part of their range;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks. Level B harassment will be primarily
in the form of behavioral disturbance, resulting in avoidance of the
project areas around where impact or vibratory pile driving is
occurring, with some low-level TTS that may limit the detection of
acoustic cues for relatively brief amounts of time in relatively
confined footprints of the activities;
<bullet> Effects on species that serve as prey for marine mammals
from the activities are expected to be short-term and, therefore, any
associated impacts on marine mammal feeding are not expected to result
in significant or long-term consequences for individuals, or to accrue
to adverse impacts on their populations;
<bullet> The project area does not overlap any BIAs or any other
important areas for marine mammals;
<bullet> The ensonified areas are small relative to the overall
habitat ranges of all species and stocks; and,
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the planned
activities will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
For all stocks, except for the Alaska stock of Dall's porpoises,
whose abundance estimate is unknown, the proposed number of takes is
less than one-third of the best available population abundance estimate
(table 9). The numbers of animals proposed for authorization to be
taken from these stocks would be considered small relative to the
relevant stocks' abundances, even if each estimated taking occurred to
a new individual--an extremely unlikely scenario.
Current abundance estimates of Dall's porpoises in the region are
not available. The most recent estimate (83,400 individuals) does not
include coastal or inland waters of southeast Alaska and is considered
unreliable since it is based upon data collected more than 8 years ago
(Young et al., 2023). However, given the size of the most recent
estimate, the 401 takes of this stock proposed for authorization
clearly represents small numbers of this stock.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals,
[[Page 14812]]
NMFS preliminarily finds that small numbers of marine mammals would be
taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
In order to issue an IHA, NMFS must find that the specified
activity will not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
That is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid 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.
There are two species of marine mammals that traditionally have
been taken as part of subsistence harvests in Resurrection Bay: Steller
sea lion and harbor seal. The most recent data on subsistence-harvested
marine mammals near Seward is of harbor seals in 2002, and there is no
current local marine mammal subsistence harvest in Seward.
The proposed project is not likely to adversely impact the
availability of any marine mammal species or stocks that are commonly
used for subsistence purposes or impact subsistence harvest of marine
mammals in the region. Although the proposed activities are located in
a region where subsistence harvests have occurred historically, there
is currently no marine mammal subsistence harvest. The project location
is adjacent to heavily traveled industrialized waterways and all
project activities will take place within waterfronts where subsistence
activities do not generally occur. Some minor, short-term harassment of
Steller sea lions and harbor seals could occur, but any effects on
subsistence harvest activities in the project areas will be minimal,
and not have an adverse impact.
Based on the description of the specified activity, the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the proposed mitigation and
monitoring measures, NMFS has preliminarily determined that there will
not be an unmitigable adverse impact on subsistence uses from ARRC's
proposed 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 insure that any action it authorizes,
funds, or carries out is not likely to jeopardize the continued
existence of any endangered or threatened species or result in the
destruction or adverse modification of designated critical habitat. To
ensure ESA compliance for the issuance of IHAs, NMFS consults
internally whenever we propose to authorize take for endangered or
threatened species, in this case with the Alaska Regional Office.
NMFS is proposing to authorize take of humpback whales (Mexico and
Western North Pacific DPS) and Steller sea lions (western DPS), which
are listed under the ESA. The Permits and Conservation Division has
requested initiation of section 7 consultation with the Alaska Region
for the issuance of this IHA. NMFS will conclude the ESA consultation
prior to reaching a determination regarding the proposed issuance of
the authorization.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to ARRC for conducting the Seward Freight Dock
construction project in Seward, Alaska from November 1, 2026, through
October 31, 2027, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated. A draft of the
proposed IHA can be found at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of proposed IHA for the proposed
construction project. We also request comment on the potential renewal
of this proposed IHA as described in the paragraph below. Please
include with your comments any supporting data or literature citations
to help inform decisions on the request for this IHA or a subsequent
renewal IHA.
On a case-by-case basis, NMFS may issue a one-time, 1-year renewal
IHA following notice to the public providing an additional 15 days for
public comments when (1) up to another year of identical or nearly
identical activities as described in the Description of Proposed
Activity section of this notice is planned or (2) the activities as
described in the Description of Proposed Activity section of this
notice would not be completed by the time the IHA expires and a renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
<bullet> A request for renewal is received no later than 60 days
prior to the needed renewal IHA effective date (recognizing that the
renewal IHA expiration date cannot extend beyond 1 year from expiration
of the initial IHA).
<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 will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: March 31, 2025.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2025-05775 Filed 4-3-25; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on April 4, 2025.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.