Notice2025-00014
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the City of Hoonah's Cargo Dock Project, Hoonah, 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
January 7, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the City of Hoonah (Hoonah) for authorization to take marine mammals incidental to pile driving and removal activities associated with the Hoonah Cargo Dock project in Hoonah, 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. 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
<html>
<head>
<title>Federal Register, Volume 90 Issue 4 (Tuesday, January 7, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 4 (Tuesday, January 7, 2025)]
[Notices]
[Pages 1084-1104]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-00014]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE481]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the City of Hoonah's Cargo Dock
Project, Hoonah, 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.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from the City of Hoonah (Hoonah)
for authorization to take marine mammals incidental to pile driving and
removal activities associated with the Hoonah Cargo Dock project in
Hoonah, 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. 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 February
6, 2025.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service and should be submitted via email to
<a href="/cdn-cgi/l/email-protection#2c65787c025b4d4f44584942484342476c42434d4d024b435a"><span class="__cf_email__" data-cfemail="cc85989ce2bbadafa4b8a9a2a8a3a2a78ca2a3adade2aba3ba">[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: Rachel Wachtendonk, 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
May 10, 2024, NMFS received a request from Hoonah for an IHA to
take marine mammals incidental to pile driving and removal activities
associated with the Hoonah Cargo Dock project in Hoonah, Alaska.
Following NMFS' review of the application, Hoonah submitted a revised
versions on September 10, 2024 and October 15, 2024. The application
was deemed adequate and complete on October 22, 2024. Hoonah's request
is for take of 8 species of marine mammals by Level B harassment and,
for a subset of these species, Level A harassment. Neither Hoonah nor
NMFS expect serious injury
[[Page 1085]]
or mortality to result from this activity and, therefore, an IHA is
appropriate.
NMFS previously issued an IHA to Hoonah for the Hoonah Cargo Dock
project (86 FR 27410, May 20, 2021), and later changed the effective
dates of the IHA in a re-issuance (87 FR 27571, May 9, 2022). However,
due to COVID and inflation no work under the IHA was conducted. Since
then, Hoonah has made several changes to their project plan and,
therefore, a new IHA is appropriate.
Description of Proposed Activity
Overview
Hoonah is proposing to install a cargo dock at the Hoonah Marine
Industrial Center (HMIC) in Hoonah, Alaska (figure 1). The purpose of
this project is to install a dock that will enable barges to land,
unload, and load during all tidal conditions and seasons. The project
is needed to allow for the safe, reliable, and economical transport of
freight to and from Hoonah, which is only accessible by air and sea.
The construction of the sheet pile cargo dock, barge ramp, and
breasting dolphins will require impact and vibratory pile installation
and down-the-hole (DTH) drilling (referred to as tension anchoring).
Sounds resulting from pile driving, pile removal, and tension
anchoring may result in the incidental take of marine mammals by Level
A and Level B harassment in the form of auditory injury or behavioral
harassment. Underwater sound would be constrained to Port Fredrick and
would be truncated by land masses in the inlet. Construction activities
would start in September 2025 and last 5 months.
Dates and Duration
The proposed IHA would be effective from September 1, 2025 through
August 31, 2026. Vibratory and impact pile driving and tension
anchoring are expected to start in September 2025 and take 107 days
over a span of 5 months. All pile driving and removal would be
completed during daylight hours.
Specific Geographic Region
The project would take place at the HMIC in Hoonah, Alaska, which
is located within Port Fredrick on Icy Strait. The proposed dock would
be constructed at an existing barge ramp, adjacent to the Hoonah ferry
terminal and tank farm.
[GRAPHIC] [TIFF OMITTED] TN07JA25.050
Detailed Description of the Specified Activity
The construction of the sheet pile cargo dock, barge ramp, and
breasting dolphins will include the installation of 542 (330 linear
feet (ft), or 100.6 linear meters (m)) steel sheet piles, 5 steel wye
piles, 1 steel X pile, 3 20-inch (in), or 0.51-m steel fender piles, 2
16-in (0.41 m) fender piles, 7 H-piles, 4 36-in (0.91 m) steel pipe
piles, and 6 36-in (0.91 m) steel batter piles. The installation and
removal of 50 temporary 24-in (0.61 m) steel pipe piles will be
completed to support the permanent pile installation. Piles will be
installed with vibratory and impact hammers, and temporary piles will
be removed with a vibratory hammer. 8-to-10-in (0.20 to 0.25 m) steel
pipe casings will be placed in each steel pipe/batter piles as tension
anchors and set with tension anchoring. Table 1 provides a summary of
the pile driving activities.
Table 1--Number and Type of Piles To Be Installed and Removed
----------------------------------------------------------------------------------------------------------------
Number of Piles Total
Activity Pile type and size piles Method per day days
----------------------------------------------------------------------------------------------------------------
Installation....................... 24-in temporary steel 50 Vibratory............. 6 9
pipe pile.
Steel sheet pile...... 542 ...................... 30 19
[[Page 1086]]
Steel wye pile........ 5 ...................... 2 3
Steel X pile.......... 1 ...................... 1 1
20-in steel fender 3 ...................... 3 1
pile.
16-in steel fender 2 ...................... 2 1
pile.
Steel H-pile.......... 7 ...................... 2 4
36-in steel pipe pile. 4 ...................... 2 2
36-in steel batter 6 ...................... 2 2
pile.
Steel sheet pile...... 542 Impact................ 15 36
Steel wye pile........ 5 ...................... 2 3
Steel X pile.......... 1 ...................... 1 1
20-in steel fender 3 ...................... 3 1
pile.
16-in steel fender 2 ...................... 2 1
pile.
Steel H-pile.......... 7 ...................... 2 4
36-in steel pipe pile. 4 ...................... 2 2
36-in steel batter 6 ...................... 4 2
pile.
8-to-10-in pipe casing 10 Tension Anchoring..... 2 5
drilling.
Removal............................ 24-in temporary steel 50 Vibratory............. 6 9
pipe pile.
----------------------------------------------------------------------------------------------------------------
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 and Pacific SARs. All values presented in table 2 are
the most recent available at the time of publication and are available
online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 2--Species \1\ Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
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\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback Whale...................... Megaptera novaeangliae. Mainland Mexico--CA/OR/ T, D, Y 3,477 (0.101, 3,185, 43 22
WA. 2018).
Hawai[revaps]i......... -, -, N 11,278 (0.56, 7,265, 127 27.09
2020).
Minke Whale......................... Balaenoptera AK..................... -, -, N N/A (N/A, N/A, N/A) UND 0
acutorostrata. \5\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale........................ Orcinus orca........... Eastern North Pacific -, -, N 1,920 (N/A, 1,920, 19 1.3
Alaska Resident. 2019) \6\.
Eastern Northern -, -, N 302 (N/A, 302, 2018) 2.2 0.2
Pacific Northern \6\.
Resident.
West Coast Transient... -, -, N 349 (N/A, 349, 2018) 3.5 0.4
\7\.
[[Page 1087]]
Pacific White-Sided Dolphin......... Lagenorhynchus N Pacific.............. -, -, N 26,880 (N/A, N/A, UND 0
obliquidens. 1990).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dall's Porpoise..................... Phocoenoides dalli..... AK..................... -, -, N UND (UND, UND, 2015) UND 37
\8\.
Harbor Porpoise..................... Phocoena phocoena...... Northern Southeast -, -, N 1,619 (0.26, 1,250, 13 5.6
Alaska Inland Waters 2019).
\9\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller Sea Lion.................... Eumetopias jubatus..... Western................ E, D, Y 49,837 (N/A, 49,837, 299 267
2022) \10\.
Eastern................ -, -, N 36,308 (N/A, 36,308, 2,178 93.2
2022) \11\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Seal......................... Phoca vitulina......... Glacier Bay/Icy Strait. -, -, N 7,455 (N/A, 6,680, 120 104
2017).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>).
\2\ 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 SARs 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\ Reliable population estimates are not available for this stock. Please see Friday et al. (2013) and Zerbini et al. (2006) for additional information
on numbers of minke whales in Alaska.
\6\ Nest is based upon counts of individuals identified from photo-ID catalogs.
\7\ Nest is based upon count of individuals identified from photo-ID catalogs in analysis of a subset of data from 1958-2018.
\8\ 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.
\9\ New stock split from Southeast Alaska stock.
\10\ 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.
\11\ 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.
As indicated above, all 8 species (with 12 managed stocks) in table
2 temporally and spatially co-occur with the activity to the degree
that take is reasonably likely to occur. All species that could
potentially occur in the project area are included in table 6 of the
IHA application. While gray whales and sperm whales have been
documented in the area, 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. Gray whales are
considered to be very rare (no local knowledge of sightings in the
project area) and sperm whales are considered to be rare (no sightings
in recent years) within the project area.
Additional information relevant to our analyses (beyond that
included above, in the application, and on NMFS website) is included
below, as appropriate. In addition, the Northern sea otter (Enhydra
lutris kenyoni) may be found in the project area. However, sea otters
are managed by the U.S. Fish and Wildlife Service and are not
considered further in this document.
Humpback Whale
The Mainland Mexico--CA/OR/WA and Hawaii stocks of humpback whale
occur in the project area. Wild et al. (2023) identified Glacier Bay
and Icy Strait as a Biologically Important Area (BIA) for humpback
whales for feeding during the months of May through October, with an
importance score of two (indicating an area of moderate importance), an
intensity score of two (indicating an area of moderate comparative
significance) and a data support score of three (highest relative
confidence in the available supporting data). Humpback whales have been
observed within Port Fredrick and Icy Strait, with most sightings
occurring from late May through October (SolsticeAK 2024).
Steller Sea Lion
Steller sea lions were listed as threatened range-wide under the
ESA on November 26, 1990 (55 FR 49204). Steller sea lions were
subsequently partitioned into the western and eastern Distinct
Population Segments (DPSs; western and eastern stocks) in 1997 (62 FR
24345, May 5, 1997). The eastern DPS remained classified as threatened
until it was delisted in November 2013. The western DPS (those
individuals west of the 144[deg] W longitude or Cape Suckling, Alaska)
was upgraded to endangered status following separation of the DPSs, and
it remains endangered today. There is regular movement of both DPSs
across this 144[deg] W longitude boundary especially within a core
mixing zone (Jemison et al., 2013). The proposed project is located
outside of the known core mixing zone of eastern DPS and western DPS
Steller sea lions; however, western DPS animals have been recorded
within the Lynn Canal extended mixing zone which includes the proposed
project area (Hastings et al., 2020; Jemison et al., 2013). Therefore,
while both DPSs could be observed within the project area, most are
expected to be from the unlisted eastern DPS.
[[Page 1088]]
Steller sea lions do not follow traditional migration patterns, but
will move from offshore rookeries in the summer to more protected
haulouts closer to shore in the winter. They use rookeries and haulouts
as resting spots as they follow prey movements and take foraging trips
for days, usually within a few miles (mi) of their rookery or haulout.
They are generalist marine predators and opportunistic feeders based on
seasonal abundance and location of prey. Steller sea lions forage in
nearshore as well as offshore areas, following prey resources. They are
highly social and are often observed in large groups while hauled out
but alone or in small groups when at sea (NMFS 2023b).
Steller sea lions are common in the proposed project area and
reside in the area year-round. The nearest rookery to the proposed
project is White Sisters (~72 kilometers (km) (44.5 mi southwest of
project) and the nearest major haulout is The Sisters (13 km (8 mi)
northeast of project) (AFSC 2023).
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 in table 3.
Table 3--Marine Mammal Hearing Groups
[NMFS, 2024a]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
UNDERWATER:
Low-frequency (LF) cetaceans 7 Hz to 36 * kHz.
(baleen whales).
High-frequency (HF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales,
beaked whales, bottlenose
whales).
Very High-frequency (VHF) 200 Hz to 165 kHz.
cetaceans (true porpoises,
Kogia, river dolphins,
Cephalorhynchid,
Lagenorhynchus cruciger & L.
australis).
Phocid pinnipeds (PW) 40 Hz to 90 kHz.
(underwater) (true seals).
Otariid pinnipeds (OW) 60 Hz to 68 kHz.
(underwater) (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 (2024a) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take of Marine Mammals section, and the Proposed Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship of individuals
and whether those impacts are reasonably expected to, or reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far. The sound level of an area is defined by the
total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic sound
(e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10 to 20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In-water construction activities associated with the project would
include impact pile installation, vibratory pile installation and
removal, and tension anchoring. Impact hammers typically operate by
repeatedly dropping and/or pushing a heavy piston onto a pile to drive
the pile into the substrate. Sound generated by impact hammers is
impulsive, characterized by rapid rise times and high peak levels, a
potentially injurious combination
[[Page 1089]]
(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 typically produce less sound (i.e.,
lower levels) than impact hammers. Peak 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; California
Department of Transportation (CALTRANS), 2015, 2020). Sounds produced
by vibratory hammers are non-impulsive; the rise time is slower,
reducing the probability and severity of injury, and the sound energy
is distributed over a greater amount of time (Nedwell and Edwards,
2002; Carlson et al., 2005). Tension anchoring through DTH systems
would also be used during the proposed construction. A DTH hammer is
essentially a drill bit that drills through the bedrock using a
rotating function like a normal drill, in concert with a hammering
mechanism operated by a pneumatic (or sometimes hydraulic) component
integrated into the DTH hammer to increase speed of progress through
the substrate (i.e., it is similar to a ``hammer drill'' hand tool).
The sounds produced by the DTH methods contain both a continuous non-
impulsive component from the drilling action and an impulsive component
from the hammering effect. Therefore, NMFS treats DTH systems as both
impulsive and continuous, non-impulsive sound source types
simultaneously.
The likely or possible impacts of Hoonah'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 the equipment and personnel; however, any impacts to marine
mammals are expected to be primarily acoustic in nature.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving is the primary means by which marine
mammals may be harassed from the proposed activity. In general, animals
exposed to natural or anthropogenic sound may experience physical and
psychological effects, ranging in magnitude from none to severe
(Southall et al., 2007). In general, exposure to pile driving and
tension anchoring noise has the potential to result in an auditory
threshold shift (TS) and behavioral reactions (e.g., avoidance,
temporary cessation of foraging and vocalizing, changes in dive
behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses, such as 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 (threshold shifts) 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). The amount of TS is customarily expressed in dB. A
TS can be permanent or temporary. As described in NMFS (2018), there
are numerous factors to consider when examining the consequence of TS,
including, but not limited to, the signal temporal pattern (e.g.,
impulsive or non-impulsive), likelihood an individual would be exposed
for a long enough duration or to a high enough level to induce a TS,
the magnitude of the TS, time to recovery (seconds to minutes or hours
to days), the frequency range of the exposure (i.e., spectral content),
the hearing frequency range of the exposed species relative to the
signal's frequency spectrum (i.e., how an animal uses sound within the
frequency band of the signal; e.g., Kastelein et al., 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Auditory Injury--NMFS defines auditory injury as damage to the
inner ear that can result in destruction of tissue . . . which may or
may not result in permanent threshold shift (PTS; NMFS, 2024a). 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,
2024a). PTS does not generally affect more than a limited frequency
range, and an animal that has 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 anthropogenic noise exposure at levels
inducing PTS are not typically pursued or authorized (NMFS, 2018).
Temporary Threshold Shift--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, 2019), 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 auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during a time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies
[[Page 1090]]
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
pinnipeds in water, measurements of TTS are limited to harbor seals,
elephant seals (Mirounga angustirostris), bearded seals (Erignathus
barbatus) and California sea lions (Zalophus californianus) (Kastak et
al., 1999, 2007; Kastelein et al., 2019a, 2019b, 2021, 2022a, 2022b;
Reichmuth et al., 2019; Sills et al., 2020). These studies examined
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 TS 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 have a lower TTS onset than other measured pinniped 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, SEL<INF>cum</INF> 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. 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, 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 dBs above that inducing mild TTS
(e.g., a 40-dB TS approximates PTS onset (Kryter et al., 1966; Miller,
1974), while a 6-dB TS 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.
Behavioral Harassment--Exposure to noise from pile driving and
removal and tension anchoring also has the potential to behaviorally
disturb marine mammals. Available studies show wide variation in
response to underwater sound; therefore, it is difficult to predict
specifically how any given sound in a particular instance might affect
marine mammals perceiving the signal. If a marine mammal does react
briefly to an underwater sound by changing its behavior or moving a
small distance, the impacts of the change are unlikely to be
significant to the individual, let alone the stock or population.
However, if a sound source displaces marine mammals from an important
feeding or breeding area for a prolonged period, impacts on individuals
and populations could be significant (e.g., Lusseau and Bejder, 2007;
Weilgart, 2007; National Research Council (NRC), 2005).
Disturbance may result in changing durations of surfacing and
dives, number of blows per surfacing, or moving direction and/or speed;
reduced/increased vocal activities; changing/cessation of certain
behavioral activities (such as socializing or feeding); visible startle
response or aggressive behavior (such as tail/fluke slapping or jaw
clapping); or avoidance of areas where sound sources are located.
Pinnipeds may increase their haulout time, possibly to avoid in-water
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound
are highly variable and context-specific and any reactions depend on
numerous intrinsic and extrinsic factors (e.g., species, state of
maturity, experience, current activity, reproductive state, auditory
sensitivity, time of day), as well as the interplay between factors
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al.,
2007; Weilgart, 2007; 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-C of Southall et al.
(2007) and Gomez et al. (2016) for a review 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
[[Page 1091]]
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 (e.g., Erbe et al., 2019). 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, Blair et al., 2016).
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. 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 relationship
between prey availability, foraging effort and success, and the life
history stage of the animal.
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.
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
[[Page 1092]]
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.,
2002a) and, more rarely, studied in wild populations (e.g., Romano et
al., 2002b). For example, Rolland et al. (2012) found that noise
reduction from reduced ship traffic in the Bay of Fundy was associated
with decreased stress in North Atlantic right whales. These and other
studies lead to a reasonable expectation that some marine mammals will
experience physiological stress responses upon exposure to acoustic
stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003), however
distress is an unlikely result of this project based on observations of
marine mammals during previous, similar projects in the area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked.
Airborne Acoustic Effects--Although pinnipeds are known to haul out
regularly at two harbor seal haulout sites within Port Fredrick, NMFS
expects that incidents of take resulting solely from airborne sound are
unlikely due to their proximity. One of the haulouts (CE79A) is located
approximately 10 km (6.25 mi) from the project site and is outside of
the ensonfied zone for this action. The other (CF39A) is located
approximately 3 km (2 mi) from the project site and will be ensonified
during some vibratory and impact pile driving activities. Neither of
these haulouts are listed as a ``key haulout,'' or a haulout with 50 or
more individuals present at the time of survey (AFSC 2024).
Cetaceans are not expected to be exposed to airborne sounds that
would result in harassment as defined under the MMPA. Airborne noise
would primarily be an issue for pinnipeds that are swimming or hauled
out near the project site within the range of noise levels elevated
above the acoustic criteria. We recognize that pinnipeds in the water
could be exposed to airborne sound that may result in behavioral
harassment when looking with their heads above water. Most likely,
airborne sound would cause behavioral responses similar to those
discussed above in relation to underwater sound. For instance,
anthropogenic sound could cause hauled-out pinnipeds to exhibit changes
in their normal behavior, such as reduction in vocalizations, or cause
them to temporarily abandon the area and move further from the source.
However, these animals would likely previously have been ``taken''
because of exposure to underwater sound above the behavioral harassment
thresholds, which are generally larger than those associated with
airborne sound. Thus, the behavioral harassment of these animals is
already accounted for in these estimates of potential take. Therefore,
we do not believe that authorization of incidental take resulting from
airborne sound for pinnipeds is warranted, and airborne sound is not
discussed further here.
Marine Mammal Habitat Effects
Hoonah's construction activities could have localized, temporary
impacts on marine mammal habitat by increasing in-water SPLs and
slightly decreasing water quality. No net habitat loss is expected,
since its proposed location is an existing barge ramp that already
experiences frequent vessel traffic and is adjacent to an active road,
ferry terminal, dock, boat haulout pier, and boat yard. Construction
activities are localized and would likely have temporary impacts on
marine mammal habitat through increases in underwater sounds. Increased
noise levels may affect acoustic habitat (see masking discussion above)
and adversely affect marine mammal prey in the vicinity of the project
area (see discussion below). During pile driving activities, elevated
levels of underwater noise would ensonify the project area where both
fishes and marine mammals may occur and could affect foraging success.
Additionally, marine mammals may avoid the area during construction;
however, displacement due to noise is expected to be temporary and is
not expected to result in long-term effects to the individuals or
populations.
Temporary and localized reduction in water quality would occur
because of in-water construction activities as well. Most of this
effect would occur during the installation and removal of piles when
bottom sediments are disturbed. The installation of piles would disturb
bottom sediments and may cause a temporary increase in suspended
sediment in the project area. In general, turbidity associated with
pile installation is localized to about 25-ft (7.6-m) radius around the
pile (Everitt et al., 1980). Pinnipeds are not expected to be close
enough to the pile driving areas to experience effects of turbidity,
and could avoid localized areas of turbidity. Therefore, we expect the
impact from increased turbidity levels to be discountable to marine
mammals and do not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat
The proposed activities would not result in permanent impacts to
habitats used directly by marine mammals outside of the actual
footprint of the constructed dock. The total seafloor area affected by
pile installation and removal is a very small area compared to the vast
foraging area available to marine mammals in Port Fredrick and the
surrounding waters. Pile extraction and installation and tension
anchoring may have impacts on benthic invertebrate species primarily
associated with disturbance of sediments that may cover or displace
some invertebrates. The impacts would be temporary and highly
localized, and no habitat would be permanently displaced by
construction. Therefore, it is expected that impacts on foraging
opportunities for marine mammals due to construction of the dock would
be minimal.
It is possible that avoidance by potential prey (i.e., fish) in the
immediate area may occur due to temporary loss of this foraging
habitat. The duration of fish avoidance of this area after pile driving
stops is unknown,
[[Page 1093]]
but we anticipate a rapid return to normal recruitment, distribution
and behavior. Any behavioral avoidance by fish of the disturbed area
would still leave large areas of fish and marine mammal foraging
habitat in the nearby vicinity in the in the project area and
surrounding waters.
Effects on Potential Prey
Construction activities would produce continuous (i.e., vibratory
pile driving and tension anchoring) and intermittent (i.e., impact
driving and tension anchoring) sounds. Sound may affect marine mammals
through impacts on the abundance, behavior, or distribution of prey
species (e.g., fish). Marine mammal prey varies by species, season, and
location. Here, we describe studies regarding the effects of noise on
known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick 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).
SPLs of sufficient strength have been known to cause injury to
fishes and fish mortality (summarized in Popper et al., 2014). 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 to 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, 2017).
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 greatest potential impact to fishes during construction would
occur during impact pile driving and tension anchoring. The duration of
impact pile driving would be limited to the final stage of installation
(``proofing'') after the pile has been driven as close as practicable
to the design depth with a vibratory driver. Only a total of 10 tension
anchors will be set over a total of 5 days of construction. 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 could 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.
The area impacted by the project is relatively small compared to
the available habitat in the remainder of Port Fredrick and the
surrounding areas, and there are no areas of particular importance that
would be impacted by this project. 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. As described
in the preceding, the potential for Hoonah's construction to affect the
availability of prey to marine mammals or to meaningfully impact the
quality of physical or acoustic habitat is considered to be
insignificant.
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 sources (i.e., pile driving and tension anchoring) has the
potential to result in disruption of behavioral patterns for individual
marine mammals. There is also some potential for auditory injury (Level
A harassment) to result, primarily for very high frequency species and
phocids because predicted auditory injury zones are larger than 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 thresholds above which NMFS believes the best
[[Page 1094]]
available science indicates marine mammals will likely be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the proposed take estimates.
Acoustic Criteria
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur auditory injury of some degree (equated
to Level A harassment). We note that the criteria for auditory injury,
as well as the names of two hearing groups, have been recently updated
(NMFS 2024a) 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 anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by TTS as, in most cases, the likelihood of
TTS occurs at distances from the source less than those at which
behavioral harassment is likely. TTS of a sufficient degree can
manifest as behavioral harassment, as reduced hearing sensitivity and
the potential reduced opportunities to detect important signals
(conspecific communication, predators, prey) may result in changes in
behavior patterns that would not otherwise occur.
Hoonah's proposed activity includes the use of continuous
(vibratory pile driving, tension anchoring) and impulsive (impact pile
driving, tension anchoring) sources, and therefore the RMS SPL
thresholds of 120 and 160 dB re 1 [mu]Pa are applicable. Tension
anchoring has both continuous and intermittent components as discussed
in the Description of Sound Sources section above. When evaluating
Level B harassment, NMFS recommends treating tension anchoring as a
continuous source and applying the RMS SPL thresholds of 120 dB re 1
[mu]Pa.
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 auditory injury (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). Hoonah's proposed activity includes the
use of impulsive (impact pile driving, tension anchoring) and non-
impulsive (vibratory pile driving, tension anchoring) sources. Tension
anchoring includes both impulsive and non-impulsive characteristics.
When evaluating Level A harassment, NMFS recommends treating tension
anchoring as an impulsive source.
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
----------------------------------------------------------------------------------------------------------------
Auditory injury onset acoustic thresholds * (received level)
Hearing group -------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.......... Cell 1: Lp,0-pk,flat: 222 Cell 2: LE,LF,24h: 197 dB.
dB; LE,LF,24h: 183 dB.
High-Frequency (HF) Cetaceans......... Cell 3: Lp,0-pk,flat: 230 Cell 4: LE,HF,24h: 201 dB.
dB; LE,HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans... Cell 5: Lpk,0-pk,flat: Cell 6: LE,p,VHF,24h: 181 dB.
202 dB; LE,p,VHF,24h:
159 dB.
Phocid Pinnipeds (PW) (Underwater).... Cell 7: Lp,0-pk,flat: 223 Cell 8: LE,p,PW,24h: 195 dB.
dB; LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)... Cell 9: Lp,0-pk,flat: 230 Cell 10: LE,p,OW,24h: 199 dB.
dB; LE,p,OW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for
calculating AUD INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure
level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-
impulsive sources.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa (underwater) and 20 [micro]Pa (in
air), and weighted cumulative sound exposure level (LE,p) has a reference value of 1 [micro]Pa2s (underwater)
and 20 [micro]Pa2s (in air). 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) or in air (i.e., 42 Hz to 52 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, OW, PA, and OA 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.
[[Page 1095]]
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.
Vessel traffic and other commercial and industrial activities in the
project area may contribute to elevated background noise levels which
may mask sounds produced by the project. Marine mammals are expected to
be affected via sound generated by the primary components of the
project (i.e., vibratory pile driving and removal, impact pile driving,
and tension anchoring).
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * Log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>),
where
TL = transmission loss in dB;
B = transmission loss coefficient;
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6-dB reduction in sound level for each doubling of
distance from the source (20*log[range]). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log[range]). A
practical spreading value of 15 is often used under conditions, such as
the project site, where water increases with depth as the receiver
moves away from the shoreline, resulting in an expected propagation
environment that would lie between spherical and cylindrical spreading
loss conditions. Practical spreading loss is assumed here.
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles, hammers, and the physical
environment in which the activity takes place. In order to calculate
the distances to the Level A harassment and the Level B harassment
sound thresholds for the methods and piles being used in this project,
the applicant and NMFS used acoustic monitoring data from other
locations to develop proxy source levels for the various pile types,
sizes and methods. The project includes vibratory, and impact pile
installation of steel pipe piles and vibratory removal of steel pipe
piles, steel fender piles, steel sheet piles, steel H-piles, steel wye
piles, steel X piles, and steel batter piles and tension anchoring
drilling. Source levels for each pile size and driving method are
presented in table 5.
NMFS recommends treating DTH systems as both impulsive and
continuous, non-impulsive sound source types simultaneously. Thus,
impulsive thresholds are used to evaluate Level A harassment, and
continuous thresholds are used to evaluate Level B harassment. NMFS
(2022) outlines its recommended source levels for DTH systems. NMFS has
applied that guidance in this analysis (see Table 5 for NMFS' proposed
source levels).
Table 5--Proxy Sound Source Levels at 10 m for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
SEL (re 1
Pile type RMS SPL (re [mu]Pa\2\- Peak SPL (re 1 Source
1 [mu]Pa) sec) [mu]Pa)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Temporary 24-in steel pipe piles. 162 NA NA PR1 2023 calculations (cited in
NMFS 2023).
20-in steel fender piles......... ........... ........... ............... ..................................
Steel sheet piles................ 160 ........... ............... Caltrans 2015 (cited in NMFS
2023).
16-in steel fender piles......... 155 ........... ............... PR1 2023 calculations (cited in
NMFS 2023).
H-piles.......................... 150 ........... ............... PR1 2023 calculations (cited in
NMFS 2023).
Wye piles........................ ........... ........... ............... NMFS 2024.
X piles..........................
36-in steel pile................. 166 ........... ............... PR1 2023 calculations (cited in
NMFS 2023).
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
20-in steel fender piles......... 190 177 203 Caltrans 2015 (cited in NMFS
2023).
Steel sheet piles................ 190 180 205 Caltrans 2015 (cited in NMFS
2023).
16-in steel fender piles......... 185 175 200 Caltrans 2020 (cited in NMFS
2023).
H-piles.......................... 183 170 210 Caltrans 2015 (cited in NMFS
2023).
Wye piles........................
X piles..........................
36-in steel pile................. 193 183 210 Caltrans 2015 & 2020 (cited in
NMFS 2023).
----------------------------------------------------------------------------------------------------------------
Tension Anchoring
----------------------------------------------------------------------------------------------------------------
6-8 in anchor hole............... 156 144 170 NMFS 2022.
----------------------------------------------------------------------------------------------------------------
All Level B harassment isopleths are reported in Table 6 below. The
maximum (underwater) area ensonified above the thresholds for
behavioral harassment is 43 km\2\ (16.6 mi\2\). However, that zone
would be truncated
[[Page 1096]]
by land masses that would obstruct underwater sound transmission and
would be limited to Port Fredrick (see figure 4 in Trident's
application).
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 auditory injury. Inputs used in the optional User Spreadsheet
tool, and the resulting estimated isopleths, are reported below.
Table 6--NMFS User Spreadsheet Inputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Activity
Weighting factor Transmission loss Number of piles duration per Number of
Pile size and type Spreadsheet tab used adjustment (kHz) coefficient per day pile strikes per
(minutes) pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Temporary 24-in steel pipe piles....... A.1 Vibratory pile driving 2.5 15 6 15 NA
20-in steel fender piles............... .......................... 2.5 15 3 30 NA
Steel sheet piles...................... .......................... 2.5 15 30 15 NA
16-in steel fender piles............... .......................... 2.5 15 2 30 NA
H-piles................................ .......................... 2.5 15 2 30 NA
Wye piles.............................. .......................... 2.5 15 3 30 NA
X piles................................ .......................... 2.5 15 1 30 NA
36-in steel pipe pile.................. .......................... 2.5 15 2 60 NA
36-in steel batter pile................ .......................... 2.5 15 2 60 NA
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-in steel fender piles............... E.1. Impact pile driving.. 2 15 3 30 600
Steel sheet piles...................... .......................... 2 15 15 30 200
16-in steel fender piles............... .......................... 2 15 2 30 600
H-piles................................ .......................... 2 15 2 30 600
Wye piles.............................. .......................... 2 15 2 30 200
X piles................................ .......................... 2 15 1 30 200
36-in steel pipe pile.................. .......................... 2 15 2 60 1,200
36-in steel batter pile................ .......................... 2 15 4 60 1,200
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tension Anchoring
--------------------------------------------------------------------------------------------------------------------------------------------------------
6-8 in anchor hole..................... E.2 DTH pile driving...... 2 15 2 60 108,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 7--Calculated Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m) Level B
Activity -------------------------------------------------------------------------------- harassment
LF-cetaceans HF-cetaceans VHF-cetaceans Phocids Otariids zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Temporary 24-in steel pipe piles........................ 16.4 6.3 13.4 21.1 7.1 7,356.4
20-in steel fender piles................................ .............. .............. .............. .............. .............. ..............
Steel sheet piles....................................... 30.3 11.6 24.8 39.0 13.1 4,641.6
16-in steel fender piles................................ 3.7 1.4 3.0 4.4 1.6 2,154.4
H-piles................................................. 1.7 0.7 1.4 2.2 0.7 1,000.0
Wye piles............................................... .............. .............. .............. .............. .............. ..............
X piles................................................. 1.1 0.4 0.9 1.4 0.5
36-in steel pipe pile................................... 31.5 12.1 25.8 40.6 13.7 11,659.1
36-in steel batter pile................................. .............. .............. .............. .............. .............. ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-in steel fender piles................................ 586.1 74.8 907.1 520.7 194.1 1,000.0
Steel sheet piles....................................... 1,305.9 166.6 2,020.9 1,160.1 432.4 ..............
16-in steel fender piles................................ 329.1 42.0 509.2 292.3 109.0 462.2
H-piles................................................. 152.7 19.5 236.4 135.7 50.6 341.5
Wye piles............................................... 73.4 9.4 113.6 65.2 24.3 ..............
X piles................................................. 46.3 5.9 71.6 41.1 15.3 ..............
36-in steel pipe pile................................... 1,783.6 227.6 2,760.1 1,584.5 590.6 1,584.9
36-in steel batter pile................................. 2,831.3 361.2 4,381.4 2,515.2 937.6 ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 1097]]
Tension Anchoring
--------------------------------------------------------------------------------------------------------------------------------------------------------
6-8 in anchor hole...................................... 90.0 11.5 139.2 79.9 29.8 2,512.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
Consultation with the Hoonah Harbormaster, applications and reports
from other nearby in water construction projects, and available
scientific literature are used to estimate the occurrence of marine
mammals in the action area. Daily occurrence probability of each marine
mammal species in the action area is based on historic data of
occurrence, seasonality, and group size in Port Frederick and Icy
Strait, and other nearby waters.
Here we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and proposed for authorization. Tables for each species
are presented to show the calculation of take during the project. NMFS
used the following equations to estimate take.
Incidental take estimate (daily) = group size * groups per day * days
of pile driving activity (107 days)
Incidental take estimate (monthly) = group size * groups per month
(considered 30 days) * months of pile driving activity (107 days/30
days per month)
Minke Whale
There are a few sightings of minke whales every year, so they could
occur every month during the project. They typically occur in groups of
two to three individuals (NMFS 2023d). Up to one group of three minke
whales are expected to occur in the project area per month. Therefore,
using the monthly equation above, NMFS proposes to authorize 11 takes
by Level B harassment of minke whales.
The largest Level A harassment zone for minke whales extends 2,831
m from the sound source (table 7). All construction work would be shut
down prior to a minke whale entering the Level A harassment zone
specific to the in-water activity underway at the time. In
consideration of the infrequent occurrence of minke whales in the
project area and proposed shutdown requirements, no take by Level A
harassment of minke whales is anticipated or proposed for
authorization.
Humpback Whale
There are multiple sightings of humpback whales every month, and
they could occur every day during the project. They typically occur in
groups of one to two individuals (Dahlheim et al., 2009). Up to one
group of two humpback whales are expected to occur in the project area
per day. Therefore, using the daily equation above, NMFS proposes to
authorize 214 takes by Level B harassment of humpback whales. In the
project area, it is estimated that the majority of whales (98 percent)
would be from the Hawaii DPS and 2 percent will be from the Mexico DPS
(Wade 2021; Muto et al. 2022). Therefore, of the 214 takes by Level B
harassment, NMFS anticipates that 210 takes would be of individuals
from the Hawaii DPS and 4 takes of individuals from the Mexico DPS.
The largest Level A harassment zone for humpback whales extends
2,831 m from the sound source (table 7). All construction work would be
shut down prior to a humpback whale entering the Level A harassment
zone specific to the in-water activity underway at the time. In
consideration that humpback whales are most often seen in Icy Strait
and the mouth of Port Fredrick and proposed shutdown requirements, no
take by Level A harassment is anticipated or proposed for authorization
for humpback whales.
Killer Whale
There are multiple sightings of killer whales every year, and they
could occur every month during the project. They typically occur in
groups of one to five individuals (NMFS 2023e). Up to four groups of
five killer whales (i.e., 20 killer whales total) are expected to occur
in the project area per month. Therefore, using the monthly equation
given above, NMFS proposes to authorize 72 takes by Level B harassment
of killer whales.
The largest Level A harassment zone for killer whales extends 361 m
from the sound source (table 7). All construction work would be shut
down prior to a killer whale entering the Level A harassment zone
specific to the in-water activity underway at the time. In
consideration of the small size of the Level A harassment zone and
proposed shutdown requirements, no take by Level A harassment of killer
whales is anticipated or proposed for authorization.
Pacific White-Sided Dolphin
There are a few sightings of Pacific white-sided dolphins every
year, but there are no sightings from recent years. However, to avoid
underestimating potential impacts from the project, in estimating take,
NMFS assumes they could occur every other month (i.e., one group every
60 days) during the project. They occur in groups of 2 to 153
individuals, but are most commonly seen in groups of 23-26 individuals
(Dahlheim et al., 2009). NMFS anticipates that up to one group of 26
Pacific white-sided dolphins could occur in the project area every
other month. Using the monthly equation above suggests that there could
be 47 takes by Level B harassment of Pacific white-sided dolphins.
However, since these dolphins can occur in large groups, NMFS proposes
to authorize 153 takes by Level B harassment in case a larger pod is
observed.
The largest Level A harassment zone for Pacific white-sided
dolphins extends 361 m from the sound source (table 7). All
construction work would be shut down prior to a Pacific white-sided
dolphin entering the Level A harassment zone specific to the in-water
activity underway at the time. In consideration of the small size of
the Level A harassment zone, proposed shutdown requirements, and
infrequent occurrence of Pacific white-sided dolphins, no take by Level
A harassment of Pacific white-sided dolphins is anticipated or proposed
for authorization.
Dall's Porpoise
There are multiple sightings of Dall's porpoises every year, and
they could occur every month during the project. They typically occur
in groups of two to five individuals (Dahlheim et al., 2009). NMFS
anticipates that up to four groups
[[Page 1098]]
of five Dall's porpoises (i.e., 20 Dall's porpoises total) could occur
in the project area per month. Therefore, using the monthly equation
given above, NMFS proposes to authorize 72 takes by Level B harassment
of Dall's porpoises.
The largest Level A harassment zone for Dall's porpoises extends
4,381 m from the sound source (table 7) during impact pile driving.
Hoonah would be required to implement shutdowns during all pile driving
activities. However, during impact pile driving of the 20-in fender
piles, 16-in fender piles, sheet piles, and 36-in piles, the Level A
harassment zones for Dall's porpoise extend beyond the shutdown zones,
and NMFS anticipates that Level A harassment could occur. Hoonah
estimates, and NMFS concurs, that up to four groups of two Dall's
porpoises could occur in the Level A harassment zone for a duration
long enough to incur auditory injury during each month of impact pile
driving (42 days of pile driving). Using the monthly equation above,
NMFS proposes to authorize 12 takes by Level A harassment of Dall's
porpoises.
Harbor Porpoise
There are multiple sightings of harbor porpoises every month, and
they could occur every day during the project. They typically occur in
groups of one to three individuals (Dahlheim et al., 2009). Up to one
group of three harbor porpoises are expected to occur in the project
area per day. Therefore, using the daily equation given above, NMFS
proposes to authorize 321 takes by Level B harassment of harbor
porpoises.
The largest Level A harassment zone for harbor porpoises extends
4,381 m from the sound source (table 7) during impact pile driving.
Hoonah would be required to implement shutdowns during all pile driving
activities. However, during impact pile driving of the 20-in fender
piles, 16-in fender piles, sheet piles, and 36-in piles, the Level A
harassment zones for the harbor porpoise extend beyond the shutdown
zone, and NMFS anticipates that Level A harassment could occur. Hoonah
expects, and NMFS concurs, that up to one group of two harbor porpoises
could be present in the Level A harassment zone for each day of impact
pile driving (42 days of pile driving). Using the daily equation given
above, NMFS proposes to authorize 84 takes by Level A harassment of
harbor porpoises.
Harbor Seal
There are a multiple sightings of harbor seals every month, and
they could occur every day during the project. They typically occur in
groups of one to four individuals (Jefferson et al., 2019). Up to one
group of two harbor seals are expected to occur in the project area per
day. Therefore, using the daily equation given above, NMFS proposes to
authorize 214 takes by Level B harassment of harbor seals. Additionally
there is a harbor seal haulout located three km (1.9 mi) from the
project site where harbor seals congregate in larger numbers. Hoonah
estimated, and NMFS concurs that up to 1 group of 20 harbor seals could
be taken by Level B harassment every month that the Level B harassment
zone is larger than 2,000 m (43 days of pile driving). Therefore, using
the monthly equation given above, NMFS proposes to authorize an
additional 29 takes by Level B harassment of harbor seals.
Cumulatively, NMFS proposes to authorize 243 takes by Level B
harassment of harbor seals.
The largest Level A harassment zone for harbor seals extends 2,515
m from the sound source (table 7) during impact pile driving. Hoonah
would be required to implement shutdowns during all pile driving
activities. However, during impact pile driving of the 20-in fender
piles, 16-in fender piles, sheet piles, and 36-in piles, the Level A
harassment zones for the harbor porpoise extend beyond the shutdown
zone, and NMFS anticipates that Level A harassment could occur. Hoonah
expects, and NMFS concurs, that up to one harbor seal could be present
in the Level A harassment zone for each day of impact pile driving (42
days of pile driving). Using the equation given above, the calculated
estimated take by Level A harassment for harbor seals would be 42.
Steller Sea Lion
There are a multiple sightings of Steller sea lions every month,
and they could occur every day during the project. They typically occur
in groups of one to four individuals (NMFS 2023f). Up to one group of
four Steller sea lions is expected to occur in the project area per
day. Therefore, using the daily equation given above, NMFS proposes to
authorize 428 takes by Level B harassment of Steller sea lions. Both
the Eastern DPS and Western DPS of Steller sea lions occur in the
project area. NMFS estimates that the majority of Steller sea lions in
the project area (99.6 percent) would be from the Eastern DPS and 1.4
percent would be from the Western DPS (Hastings et al., 2020).
Therefore, of the 428 total takes by Level B harassment, NMFS
anticipates that 422 takes would be of individuals from the Eastern DPS
and 6 takes of individuals from the Western DPS.
The largest Level A harassment zone for Steller sea lions extends
938 m from the sound source (table 7). All construction work would be
shut down prior to a Steller sea lion entering the Level A harassment
zone specific to the in-water activity underway at the time. In
consideration of the proposed shutdown requirements, no take by Level A
harassment is anticipated or proposed for Steller sea lions.
Table 8--Estimated Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock Proposed take as
Common name Stock abundance Level A Level B Total proposed percentage of
\1\ harassment harassment take stock \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke whale................................ Alaska........................ UND 0 11 11 \3\ UND
Humpback whale............................. Hawaii DPS.................... 11,278 0 214 214 1.9
Mexico DPS.................... 3,477 ............ ............ ............... 6.1
Killer whale............................... Eastern North Pacific Alaska 1,920 0 72 72 3.8
Resident.
West Coast Transient.......... 349 ............ ............ ............... 20.6
Eastern North Pacific Northern 302 ............ ............ ............... 23.8
Resident.
Pacific white-sided dolphin................ North Pacific................. 26,880 0 153 153 0.6
Dall's porpoise............................ Alaska........................ UND 12 72 83 \4\ UND
Harbor porpoise............................ Northern Southeast Alaska 1,619 84 321 403 24.9
Inland Waters.
Harbor seal................................ Glacier Bay/Icy Strait........ 7,455 42 243 298 4.0
Steller sea lion........................... Western DPS................... 49,837 0 428 428 0.9
Eastern DPS................... 36,308 ............ ............ ............... 1.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Stock size is Nbest according to NMFS 2023 Draft SARs, unless otherwise noted.
[[Page 1099]]
\2\ Percent of stock reflects the combined total of take by Level B and Level A harassment (if requested). If a species has multiple stocks, NMFS
conservatively assumes that all takes occur to each stock.
\3\ The Alaska SAR does not have an estimated population size for the Alaska stock of minke whales due to only a portion of the stock's range being
surveyed and such few whales seen during stock abundance surveys.
\4\ 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.
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 (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, and impact on
operations.
The mitigation measures described in the following paragraphs would
apply to the Hoonah's in-water construction activities.
Shutdown Zones and Monitoring
Hoonah must establish shutdown zones for all pile driving
activities. The purpose of a shutdown zone is generally to define an
area within which shutdown of the activity would occur upon sighting of
a marine animal (or in anticipation of an animal entering the defined
area). Shutdown zones vary based on the activity type and duration and
marine mammal hearing group, as shown in table 9. A minimum shutdown
zone of 10 m would be required for all in-water construction activities
to avoid physical interaction with marine mammals. Marine mammal
monitoring would be conducted during all pile driving activities to
ensure that shutdowns occur, as required. Proposed shutdown zones for
each activity type are shown in table 9.
Prior to pile driving, shutdown zones would be established based on
zones represented in table 9. Observers would survey the shutdown zones
for at least 30 minutes before pile driving activities start. If marine
mammals are observed within the shutdown zone, pile driving and tension
anchoring will be delayed until the animal has moved out of the
shutdown zone, either verified by an observer or by waiting until 15
minutes has elapsed without a sighting of small cetaceans, delphinids,
and pinnipeds; or 30 minutes has elapsed without a sighting of a large
cetacean. If a marine mammal approaches or enters the shutdown zone
during pile driving or tension anchoring, the activity would be halted.
If a species for which authorization has not been granted, or a species
which has been granted but the authorized takes are met, is observed
approaching or within the Level B harassment zone during pile driving
or tension anchoring, the activity would be halted. Pile driving may
resume after the animal has moved out of and is moving away from the
shutdown zone (or Level B harassment zone for which authorization has
not been granted, or a species which has been granted but the
authorized takes are met) or after at least 15 minutes has passed since
the last observation of the animal.
All marine mammals would 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 would continue and PSOs would document the animal's presence
within the estimated harassment zone.
Table 9--Shutdown and Level B Harassment Zones by Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minimum shutdown zone (m) Level B
Activity -------------------------------------------------------------------------------- harassment
LF- cetaceans HF- cetaceans VHF- cetaceans Phocids Otariids zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Temporary 24-in steel pipe piles........................ 20 10 15 25 10 7,360
20-in steel fender piles................................ .............. .............. .............. .............. .............. ..............
Steel sheet piles....................................... 35 15 25 40 15 4,645
16-in steel fender piles................................ 10 10 10 10 10 2,155
H-piles................................................. 10 10 10 10 10 1,000
Wye piles............................................... .............. .............. .............. .............. .............. ..............
X piles................................................. .............. .............. .............. .............. .............. ..............
36-in steel pipe pile................................... 35 15 30 45 15 11,660
36-in steel batter pile................................. .............. .............. .............. .............. .............. ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-in steel fender piles................................ 590 75 200 200 195 1,000
Steel sheet piles....................................... 1,310 170 200 200 435 ..............
16-in steel fender piles................................ 330 42 200 200 110 465
H-piles................................................. 155 20 200 140 55 345
Wye piles............................................... 75 10 115 70 25 ..............
X piles................................................. 50 10 75 45 20 ..............
[[Page 1100]]
36-in steel pipe pile................................... 1,785 230 200 200 595 1,5890
36-in steel batter pile................................. 2,835 365 200 200 940 ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tension Anchoring
--------------------------------------------------------------------------------------------------------------------------------------------------------
6-8 in anchor hole...................................... 90 15 140 80 30 2,515
--------------------------------------------------------------------------------------------------------------------------------------------------------
Protected Species Observers
The placement of Protected Species Observers (PSO) during all pile
driving activities (described in the Proposed Monitoring and Reporting
section) would ensure that the entire shutdown zone is visible. Should
environmental conditions deteriorate such that the entire shutdown zone
would not be visible (e.g., fog, heavy rain), pile driving would be
delayed until the PSO is confident marine mammals within the shutdown
zone could be detected.
PSOs would monitor the full shutdown zones and as much of the Level
B harassment zones as possible. Monitoring enables observers to be
aware of and communicate the presence of marine mammals in the project
areas outside the shutdown zones and thus prepare for a potential
cessation of activity should the animal enter the shutdown zone.
Pre- and Post-Activity Monitoring
Monitoring must take place from 30 minutes prior to initiation of
pile driving activities (i.e., pre-clearance monitoring) through 30
minutes post-completion of pile driving. Prior to the start of daily
in-water construction activity, or whenever a break in pile driving of
30 minutes or longer occurs, PSOs would observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone would be
considered cleared when a marine mammal has not been observed within
the zone for a 30-minute period. If a marine mammal is observed within
the shutdown zones, pile driving activity would be delayed or halted.
If work ceases for more than 30 minutes, the pre-activity monitoring of
the shutdown zones would commence. A determination that the shutdown
zone is clear must be made during a period of good visibility (i.e.,
the entire shutdown zone and surrounding waters must be visible to the
naked eye).
Soft Start
Soft-start procedures provide additional protection to marine
mammals by providing warning and/or giving marine mammals a chance to
leave the area prior to the impact hammer operating at full capacity.
Hoonah must implement soft start techniques when impact pile driving.
Soft start requires contractors to conduct an initial set of three
strikes at reduced energy, followed by a 30-second waiting period, then
two subsequent three-strike sets before initiating continuous driving.
Soft start will 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.
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
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
Marine Mammal Monitoring and Mitigation Plan and section 5 of the IHA.
Hoonah's draft Marine Mammal Monitoring and Mitigation Plan is Appendix
D of the IHA application. Prior to the beginning of construction,
Hoonah would submit a revised Marine Mammal Mitigation and Monitoring
Plan containing additional details of monitoring locations and
methodology for NMFS concurrence.
Marine mammal monitoring during pile driving and removal must be
conducted by NMFS-approved PSOs in a manner consistent with the
following:
<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
[[Page 1101]]
pursuant to a NMFS-issued incidental take authorization;
<bullet> Other PSOs may substitute 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. PSOs may also substitute Alaska
native traditional knowledge for experience;
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization; and PSOs must be approved by NMFS prior to beginning any
activity subject to this IHA.
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.
Between one and three PSOs will be on duty depending on the size of
the Level B harassment zone. PSOs will establish monitoring locations
as described in the Marine Mammal Mitigation and Monitoring Plan.
Monitoring locations would be selected by the Contractor during pre-
construction. PSOs would monitor for marine mammals entering the Level
B harassment zones; the position(s) may vary based on construction
activity and location of piles or equipment.
Monitoring would be conducted 30 minutes before, during, and 30
minutes after pile driving/removal activities. In addition, observers
shall record all incidents of marine mammal occurrence, regardless of
distance from activity, and shall document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving/
removal activities include the time to install or remove a single pile
or series of piles, as long as the time elapsed between uses of the
pile driving equipment is no more than 30 minutes.
Data Collection
PSOs would use approved data forms to record the following
information:
<bullet> Dates and times (beginning and end) of all marine mammal
monitoring; and
<bullet> PSO locations during marine mammal monitoring.
<bullet> Construction activities occurring during each daily
observation period, including how many and what type of piles were
driven or removed and by what method (i.e., vibratory, impact, or
tension anchoring).
<bullet> Weather parameters and water conditions;
<bullet> The number of marine mammals observed, by species,
relative to the pile location and if pile driving or removal was
occurring at time of sighting;
<bullet> Distance and bearings of each marine mammal observed to
the pile being driven or removed;
<bullet> Description of marine mammal behavior patterns, including
direction of travel;
<bullet> Age and sex class, if possible, of all marine mammals
observed; and
<bullet> Detailed information about implementation of any
mitigation triggered (such as shutdowns and delays), a description of
specific actions that ensued, and resulting behavior of the animal if
any.
Reporting
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of monitoring or 60 calendar days
prior to the requested issuance of any subsequent IHA for construction
activity at the same location, whichever comes first. It would include
an overall description of work completed, a narrative regarding marine
mammal sightings, and associated PSO data sheets. Specifically, the
report must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact, vibratory, tension
anchoring). The total duration of driving time must be recorded for
each pile during vibratory driving and, number or strikes for each pile
during impact driving, and the duration of operation of drilling and
components for tension anchoring;
<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 time of sighting; (2) time of sighting; (3)
identification of the animal(s) (e.g., genus/species, lowest possible
taxonomic level, or unidentified), PSO confidence in identification,
and the composition of the group if there is a mix of species; (4)
distance and bearing of each marine mammal observed relative to the
pile being driven for each sighting (if pile driving was occurring at
time of sighting); (5) estimated number of animals (min/max/best
estimate); (6) estimated number of animals by cohort (adults,
juveniles, neonates, group composition, etc.); (7) animal's closest
point of approach and estimated time spent within the harassment zone;
and (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, by species; and
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
final report would constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, Hoonah shall report the
incident to the Office of Protected Resources (OPR), NMFS and to the
Alaska regional
[[Page 1102]]
stranding network as soon as feasible. If the death or injury was
clearly caused by the specified activity, Hoonah must immediately cease
the specified activities until NMFS is able to review the circumstances
of the incident and determine what, if any, additional measures are
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS. The
report must include the following information:
<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 in the analysis below.
Pile driving and tension anchoring activities have the potential to
disturb or displace marine mammals. Specifically, the project
activities may result in take, in the form of Level A harassment
(Dall's porpoise, harbor porpoise, and harbor seal) and Level B
harassment from underwater sounds generated from pile driving and
removal and tension anchoring. 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 mortality or serious injury is anticipated
given the nature of the activity, even in the absence of the required
mitigation. The potential for harassment is minimized through the
construction method and the implementation of the proposed mitigation
measures (see Proposed Mitigation section).
Take would occur within a limited, confined area (Port Fredrick) of
the stocks' ranges. The intensity and duration of take by Level A
harassment and Level B harassment would be minimized through use of
mitigation measures described herein. Further, the amount of take
proposed to be authorized is extremely small when compared to stock
abundance, and the project is not anticipated to impact any known
important habitat areas for any marine mammal species with the
exception of a known biologically important area for humpback whales,
discussed below.
Take by Level A harassment is authorized to account for the
potential that an animal could enter and remain within the area between
a Level A harassment zone and the shutdown zone for a duration long
enough to be taken by Level A harassment. Any take by Level A
harassment is expected to arise from, at most, a small degree of
auditory injury because animals would need to be exposed to higher
levels and/or longer duration than are expected to occur here in order
to incur any more than a small degree of auditory injury. Additionally,
and as noted previously, some subset of the individuals that are
behaviorally harassed could also simultaneously incur some small degree
of TTS for a short duration of time. Because of the small degree
anticipated, though, any auditory injury or TTS potentially incurred
here would not be expected to adversely impact individual fitness, let
alone annual rates of recruitment or survival.
Behavioral responses of marine mammals to pile driving at the
project site, if any, are expected to be mild and temporary. Marine
mammals within the Level B harassment zone may not show any visual cues
they are disturbed by activities or 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 the limited number of
piles to be installed or extracted per day and that pile driving and
removal would occur across a maximum of 107 days within the 12-month
authorization period, any harassment would be temporary.
Any impacts on marine mammal prey that would occur during Hoonah's
proposed activity would 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.
In addition, it is unlikely that elevated noise in a small,
localized area of habitat would have any effect on 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 will have only minor, short-term effects on individuals. The
specified activities are not expected to impact rates of recruitment or
survival, and will therefore not result in population-level impacts.
The waters of Glacier Bay and Icy Strait are part of the Alaska
humpback whale feeding BIA (Wild et al., 2023). However, underwater
sound would be constrained to Port Fredrick and would be truncated by
land masses in the inlet. The area of the BIA that may be affected
[[Page 1103]]
by the proposed project is small relative to the overall area of the
BIA. The humpback whale feeding BIA is active between May and October
while the proposed project is scheduled to occur between September and
January, resulting in only 2 months of overlap. Additionally, pile
driving associated with the project is expected to take only 107 days,
further reducing the temporal overlap with the BIA. Therefore, the
proposed project is not expected to have significant adverse effects on
the foraging of Alaska humpback whale.
There are two known harbor seal haulouts within Port Fredrick. One
of the haulouts (CE79A) is located approximately 10 km (6.25 mi) from
the project site and is outside of the ensonfied zone for this action.
The other (CF39A) is located approximately 3 km (2 mi) from the project
site and will be ensonified during some vibratory and impact pile
driving activities. Neither of these haulouts are listed as a ``key
haulout,'' or a haulout with 50 or more individuals present at the time
of survey (AFSC 2024). Given that these are not considered key
haulouts, and the maximum of 43 days that the ensonified zone will
extend over 2 km, the proposed project is not expected to have
significant adverse effects on harbor seal haulout sites. No areas of
specific biological importance (e.g., ESA critical habitat, other BIAs,
or other areas) for any other species are known to co-occur with the
project area.
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> For all species except Dall's porpoises, harbor porpoises,
and harbor seals, no Level A harassment is anticipated or proposed for
this action;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks and would not be of a duration or
intensity expected to result in impacts on reproduction or survival;
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat;
<bullet> With the exception of the humpback whale BIA described
above, no areas of specific biological importance (e.g., ESA critical
habitat, other BIAs, or other areas) for any other species are known to
co-occur with the project area; and
<bullet> Hoonah would implement mitigation measures, such as soft-
starts for impact pile driving and shutdowns to minimize the numbers of
marine mammals exposed to injurious levels of sound, and to ensure that
take by Level A harassment, is at most, a small degree of auditory
injury.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
For all stocks, except for the Alaska stock of minke whales and 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 8). 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 83 takes of this stock proposed for authorization clearly
represents small numbers of this stock.
There is no current or historical estimate of the Alaska minke
whale stock, but there are known to be over 1,000 minke whales in the
Gulf of Alaska (Muto et al. 2018), so the 11 takes proposed for
authorization is small relative to estimated survey abundance, even if
each proposed take occurred to a new individual. Additionally, the
range of the Alaska stock of minke whales is extensive, stretching from
the Canadian Pacific coast to the Chukchi Sea, and Hoonah's proposed
project area would impact a small portion of this range.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals would be taken relative to the population
size of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
In order to issue an IHA, NMFS must find that the specified
activity will not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
That is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid hunting areas; (ii) Directly
displacing subsistence users; or (iii) Placing physical barriers
between the marine mammals and the subsistence hunters; and (2) That
cannot be sufficiently mitigated by other measures to increase the
availability of marine mammals to allow subsistence needs to be met.
Alaska Natives have traditionally harvested subsistence resources,
including marine mammals, in the Glacier Bay and Icy Strait for a
millennia. Present day Hoonah is the principle village of the Huna
tribe, and according to Ian Johnson, Hoonah Indian Association's
Environmental Coordinator, no known marine mammal harvest takes place
in the immediate HMIC area (Johnson 2024). Limited subsistence harvests
of marine mammals within Port Fredrick has occurred in the past, with
the most recent recorded/documented harvests of marine mammals in
Hoonah in 2012. The proposed activity will take place in Port Fredrick,
and no activities overlap with current subsistence hunting areas;
therefore, there are no relevant subsistence uses of marine mammals
adversely impacted by this action. The proposed project is not likely
to
[[Page 1104]]
adversely impact the availability of any marine mammal species or
stocks that are commonly used for subsistence purposes or to impact
subsistence harvest of marine mammals in the region.
Based on the description of the specified activity, the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the proposed mitigation and
monitoring measures, NMFS has preliminarily determined that there will
not be an unmitigable adverse impact on subsistence uses from Hoonah'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 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 Hoonah for conducting the Hoonah Cargo Dock Project in
Hoonah, Alaska from September 1, 2025 through August 31, 2026, provided
the previously mentioned mitigation, monitoring, and reporting
requirements are incorporated. A draft of the proposed IHA can be found
at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>.
Request for Public Comments
We request 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);
and
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized; and
<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: January 2, 2025.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2025-00014 Filed 1-6-25; 8:45 am]
BILLING CODE 3510-22-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on January 7, 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.