Notice2024-16166
Marine Mammals; Incidental Take During Specified Activities; Proposed Incidental Harassment Authorization for Southcentral Alaska Stock of Northern Sea Otters in Whittier, AK; Draft Environmental Assessment
Primary source
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Published
July 23, 2024
Issuing agencies
Interior DepartmentFish and Wildlife Service
Abstract
We, the U.S. Fish and Wildlife Service (FWS), in response to a request under the Marine Mammal Protection Act of 1972, as amended, from Turnagain Marine Construction, propose to authorize nonlethal, incidental take by harassment of small numbers of Southcentral Alaska stock northern sea otters (Enhydra lutris kenyoni) from July 19, 2024, to July 18, 2025. The applicant has requested this authorization for take by harassment that may result from activities associated with pile driving and marine construction activities on the western shore of Passage Canal in Whittier, Alaska. We estimate that this project may result in the nonlethal incidental take by harassment of up to 162 northern sea otters from the Southcentral stock. This proposed authorization, if finalized, will be for up to 17 takes of northern sea otters by Level A harassment and 145 takes of northern sea otters by Level B harassment. Neither the applicant nor the FWS anticipated any lethal take, and the FWS does not propose to authorize any lethal take. We invite comments on the proposed incidental harassment authorization and the accompanying draft environmental assessment from the public, and local, State, Tribal and Federal agencies.
Full Text
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<title>Federal Register, Volume 89 Issue 141 (Tuesday, July 23, 2024)</title>
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[Federal Register Volume 89, Number 141 (Tuesday, July 23, 2024)]
[Notices]
[Pages 59752-59765]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-16166]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
[Docket No. FWS-R7-ES-2024-0054; FXES111607MRG01-245-FF07CAMM00]
Marine Mammals; Incidental Take During Specified Activities;
Proposed Incidental Harassment Authorization for Southcentral Alaska
Stock of Northern Sea Otters in Whittier, AK; Draft Environmental
Assessment
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of receipt of application and proposed authorization;
notice of availability of draft environmental assessment; request for
comments.
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SUMMARY: We, the U.S. Fish and Wildlife Service (FWS), in response to a
request under the Marine Mammal Protection Act of 1972, as amended,
from Turnagain Marine Construction, propose to authorize nonlethal,
incidental take by harassment of small numbers of Southcentral Alaska
stock northern sea otters (Enhydra lutris kenyoni) from July 19, 2024,
to July 18, 2025. The applicant has requested this authorization for
take by harassment that may result from activities associated with pile
driving and marine construction activities on the western shore of
Passage Canal in Whittier, Alaska. We estimate that this project may
result in the nonlethal incidental take by harassment of up to 162
northern sea otters from the Southcentral stock. This proposed
authorization, if finalized, will be for up to 17 takes of northern sea
otters by Level A harassment and 145 takes of northern sea otters by
Level B harassment. Neither the applicant nor the FWS anticipated any
lethal take, and the FWS does not propose to authorize any lethal take.
We invite comments on the proposed incidental harassment authorization
and the accompanying draft environmental assessment from the public,
and local, State, Tribal and Federal agencies.
DATES: Comments must be received by August 22, 2024.
ADDRESSES: Document availability: You may view the application package,
supporting information, the draft environmental assessment, and the
list of references cited herein at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under
Docket No. FWS-R7-ES-2024-0054, or you may request these documents from
the person listed under FOR FURTHER INFORMATION CONTACT.
Comment submission: You may submit comments on the proposed
authorization by one of the following methods:
<bullet> Internet: <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the
instructions for submitting comments to Docket No. FWS-R7-ES-2024-0054.
<bullet> U.S. mail: Public Comments Processing, Attn: Docket No.
FWS-R7-ES-2024-0054, U.S. Fish and Wildlife Service, MS: PRB (JAO/3W),
5275 Leesburg Pike, Falls Church, VA 22041-3803.
We will post all comments at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. You may
request that we withhold personal identifying information from public
review; however, we cannot guarantee that we will be able to do so. See
Request for Public Comments for more information.
FOR FURTHER INFORMATION CONTACT: Charles Hamilton, by email at
<a href="/cdn-cgi/l/email-protection#095b3e6464647b6c6e7c65687d667b70496f7e7a276e667f"><span class="__cf_email__" data-cfemail="df8de8b2b2b2adbab8aab3beabb0ada69fb9a8acf1b8b0a9">[email protected]</span></a>, or by telephone at 1-800-362-5148 or 1-907-
786-3800. Individuals in the United States who are deaf, deafblind,
hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or
TeleBraille) to access telecommunications relay services. Individuals
outside the United States should use the relay services offered within
their country to make international calls to the point-of-contact in
the United States.
SUPPLEMENTARY INFORMATION:
Background
Section 101(a)(5)(D) of the Marine Mammal Protection Act of 1972
(MMPA; 16 U.S.C. 1361 et seq.) authorizes the Secretary of the Interior
(Secretary) to allow, upon request, the incidental, but not
intentional, taking by harassment of small numbers of marine mammals in
response to requests by U.S. citizens (as defined in title 50 of the
Code of Federal Regulations (CFR) in part 18, at 50 CFR 18.27(c))
engaged in a specified activity (other than commercial fishing) in a
specified geographic region during a period of not more than 1 year.
The Secretary has delegated authority for implementation of the MMPA to
the U.S. Fish and Wildlife Service (FWS, or we). According to the MMPA,
the FWS shall allow this incidental taking by harassment if we make
findings that the total of such taking for the 1-year period:
1. Is of small numbers of marine mammals of a species or stock;
2. Will have a negligible impact on such species or stocks; and
3. Will not have an unmitigable adverse impact on the availability
of these species or stocks for taking for subsistence use by Alaska
Natives.
If the requisite findings are made, we issue an authorization that
sets forth the following, where applicable:
1. Permissible methods of taking;
2. Means of effecting the least practicable adverse impact on the
species or stock and its habitat and the availability of the species or
stock for subsistence uses; and
3. Requirements for monitoring and reporting of such taking by
harassment, including, in certain circumstances, requirements for the
independent peer review of proposed monitoring plans or other research
proposals.
The term ``take'' means to harass, hunt, capture, or kill, or to
attempt to harass, hunt, capture, or kill any marine mammal.
``Harassment'' means any act of pursuit, torment, or annoyance which
(i) has the potential to injure a marine mammal or marine mammal stock
in the wild (the MMPA defines this as ``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 (the MMPA defines this as ``Level B harassment'').
The terms ``negligible impact'' and ``unmitigable adverse impact''
are defined in 50 CFR 18.27 (i.e., regulations governing small takes of
marine mammals incidental to specified activities) as follows:
``Negligible impact'' is 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. ``Unmitigable adverse impact''
means 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
[[Page 59753]]
the availability of marine mammals to allow subsistence needs to be
met.
The term ``small numbers'' is also defined in 50 CFR 18.27.
However, we do not rely on that definition here as it conflates ``small
numbers'' with ``negligible impacts.'' We recognize ``small numbers''
and ``negligible impacts'' as two separate and distinct considerations
when reviewing requests for incidental harassment authorizations (IHA)
under the MMPA (see Natural Res. Def. Council, Inc. v. Evans, 232 F.
Supp. 2d 1003, 1025 (N.D. Cal. 2003)). Instead, for our small numbers
determination, we estimate the likely number of takes of marine mammals
and evaluate if that take is small relative to the size of the species
or stock.
The term ``least practicable adverse impact'' is not defined in the
MMPA or its enacting regulations. For this IHA, we ensure the least
practicable adverse impact by requiring mitigation measures that are
effective in reducing the impact of project activities, but they are
not so restrictive as to make project activities unduly burdensome or
impossible to undertake and complete.
If the requisite findings are made, we shall issue an IHA, which
may set forth the following, where applicable: (i) permissible methods
of taking; (ii) 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 subsistence
uses by coastal-dwelling Alaska Natives (if applicable); and (iii)
requirements for monitoring and reporting take by harassment.
Summary of Request
On March 1, 2024, Turnagain Marine Construction (hereafter, TMC or
the applicant) submitted a request to the FWS for an authorization to
take by Level A harassment and Level B harassment a small number of
northern sea otters (Enhydra lutris kenyoni) (hereafter, sea otters or
otters unless another species is specified) from the Southcentral
Alaska stock. The FWS sent a request for additional information on
March 15, 2024. We received updated versions of the request on March
18, 2024. The FWS determined the March 18, 2024, application to be
adequate and complete. The applicant expects take by harassment may
occur during the construction of their cruise ship berth and associated
facilities on the western shore of Passage Canal in Whittier, Alaska.
Description of Specified Activities and Specified Geographic Region
The specified activity (hereafter project) will include
installation and removal of piles for the construction of a 152-by-21-
meter (m) (500-by-70-foot (ft)) floating cruise ship dock in Whittier,
Alaska (figure 1). The applicant, TMC, plans to install and remove 15
temporary steel piles, each of which will be 91 centimeters (cm) (36
inches (in)) in diameter, and expects to install 7 permanent steel
piles, each 91 cm (36 in) in diameter, and 8 permanent steel piles,
each 122 cm (48 in) in diameter. Dock components that will be installed
out of water include bull rail, fenders, mooring cleat, pre-cast
concrete dock surface, and mast lights. Pile-driving activities will
occur over 31 non-consecutive days for approximately 70 hours between
July 19, 2024, and July 18, 2025. If the IHA is issued after TMC's
intended start date, its schedule for conducting the specified
activities may be adjusted accordingly. Pile installation will be done
with a combination of impact, vibratory, and down-the-hole (DTH)
drilling. Temporary piles will be removed with the vibratory hammer.
Materials and equipment will be transported via barges and workers will
be transported to and from the barge work platform via skiff.
Additional project details may be reviewed in the application
materials available as described under ADDRESSES or may also be
requested as described under FOR FURTHER INFORMATION CONTACT.
[[Page 59754]]
[GRAPHIC] [TIFF OMITTED] TN23JY24.006
[[Page 59755]]
Description of Marine Mammals in the Specified Geographic Region
The northern sea otter is the only species of marine mammal under
FWS jurisdiction likely found within the specified geographic region.
Information on range, stocks, and biology of sea otters can be found in
the supplemental information (available as described above in
ADDRESSES).
Potential Impacts of the Specified Activities on Marine Mammals
Effects of Noise on Sea Otters
We characterize ``noise'' as sound released into the environment
from human activities that exceeds ambient levels or interferes with
normal sound production or reception by sea otters. The terms
``acoustic disturbance'' and ``acoustic harassment'' are disturbances
or harassment events resulting from noise exposure. Potential effects
of noise exposure are likely to depend on the distance of the sea otter
from the sound source, the level and intensity of sound the sea otter
receives, background noise levels, noise frequency, noise duration, and
whether the noise is pulsed or continuous. The actual noise level
perceived by individual sea otters will also depend on whether the sea
otter is above or below water and atmospheric and environmental
conditions. Temporary disturbance of sea otters or localized
displacement reactions are the most likely effects to occur from noise
exposure. No lethal take is anticipated nor was authorization of lethal
take requested by the applicant. Therefore, none will be authorized.
Sea Otter Hearing
Pile driving and marine construction activities produce sound that
will fall within the hearing range of sea otters. Controlled sound
exposure trials on southern sea otters (Enhydra lutris nereis) indicate
that sea otters can hear frequencies between 125 hertz (Hz) and 38
kilohertz (kHz), with best sensitivity between 1.2 and 27 kHz (Ghoul
and Reichmuth 2014). Aerial and underwater audiograms for a captive
adult male southern sea otter in the presence of ambient noise suggest
the sea otter's hearing was less sensitive to high-frequency (greater
than 22 kHz) and low-frequency (less than 2 kHz) sound than that of
terrestrial mustelids but was similar to that of a California sea lion
(Zalophus californianus). However, the sea otter was still able to hear
low-frequency sounds, and the detection thresholds for sounds between
0.125 and 1 kHz were between 116 and 101 decibels (dB), respectively.
Dominant frequencies of southern sea otter vocalizations are between 3
and 8 kHz, with some energy extending above 60 kHz (McShane et al.
1995; Ghoul and Reichmuth 2012).
Exposure to high levels of sound may cause changes in behavior,
masking of communications, temporary or permanent changes in hearing
sensitivity, discomfort, and injury to marine mammals. Unlike other
marine mammals, sea otters do not rely on sound to orient themselves,
locate prey, or communicate under water; therefore, masking of
communications by anthropogenic sound is less of a concern than for
other marine mammals. However, sea otters, especially mothers and pups,
do use sound for communication in air (McShane et al. 1995) and sea
otters may monitor underwater sound to avoid predators (Davis et al.
1987).
Exposure Thresholds
Underwater Sounds
Noise exposure criteria for identifying underwater noise levels
capable of causing Level A harassment (which entails the potential for
injury) to marine mammal species, including sea otters, have been
established using the same methods as those used by the National Marine
Fisheries Service (NMFS) (Southall et al. 2019). These criteria are
based on estimated levels of sound exposure capable of causing a
permanent shift in hearing sensitivity (i.e., a permanent threshold
shift (PTS) (NMFS 2018)). A PTS occurs when noise exposure causes hairs
within the inner ear system to die (Ketten 2012). Although the effects
of PTS are, by definition, permanent, PTS does not equate to total
hearing loss.
Sound exposure thresholds incorporate two metrics of exposure: the
peak level of instantaneous exposure likely to cause PTS and the
cumulative sound exposure level (SEL<INF>CUM</INF>) during a 24-hour
period. They also include weighting adjustments for the sensitivity of
different species to varying frequencies. The PTS-based injury criteria
were developed from theoretical extrapolation of observations of
temporary threshold shifts (TTS) detected in lab settings during sound
exposure trials (Finneran 2015). The TTS is a noise-induced threshold
shift in hearing sensitivity that fully recovers over time (Finneran
2015). Southall and colleagues (2019) predict that PTS for sea otters,
which are included in the ``other marine carnivores'' category, will
occur at 232 dB peak or 203 dB SEL<INF>CUM</INF> for impulsive
underwater sound and 219 dB SEL for nonimpulsive (continuous)
underwater sound.
Thresholds based on TTS have been used as a proxy for Level B
harassment (i.e., 70 FR 1871, January 11, 2005; 71 FR 3260, January 20,
2006; 73 FR 41318, July 18, 2008). Southall et al. (2007) derived TTS
thresholds for pinnipeds based on 212 dB peak and 171 dB SEL. Exposures
resulting in TTS in pinnipeds were found to range from 152 to 174 dB
(183 to 206 dB SEL) (Kastak et al. 2005), with a persistent TTS, if not
a PTS, after 60 seconds of 184 dB SEL (Kastak et al. 2008). Kastelein
et al. (2012) found small but statistically significant TTSs at
approximately 170 dB SEL (136 dB, 60 minutes) and 178 dB SEL (148 dB,
15 minutes). Based on these findings, Southall et al. (2019) developed
TTS thresholds for sea otters, which are included in the ``other marine
carnivores'' category, of 188 dB SEL for impulsive sounds and 199 dB
SEL for nonimpulsive sounds.
The NMFS (2018) criteria do not identify thresholds for avoidance
of Level B harassment. For pinnipeds (seals and sea lions), NMFS has
adopted a 160-dB threshold for Level B harassment from exposure to
impulsive noise and a 120-dB threshold for continuous noise (NMFS 1998;
HESS 1999; NMFS 2018). These thresholds were developed from
observations of mysticete (baleen) whales responding to airgun
operations (e.g., Malme et al. 1983; Malme and Miles 1983; Richardson
et al. 1986, 1995) and from equating Level B harassment with noise
levels capable of causing TTS in lab settings. Southall et al. (2007,
2019) assessed behavioral response studies and found considerable
variability among pinnipeds. The authors determined that exposures
between approximately 90 to 140 dB generally do not appear to induce
strong behavioral responses from pinnipeds in water. However, they
found behavioral effects, including avoidance, become more likely in
the range between 120 and 160 dB, and most marine mammals showed some,
albeit variable, responses to sound between 140 and 180 dB. Wood et al.
(2012) adapted the approach identified in Southall et al. (2007) to
develop a probabilistic scale for marine mammal taxa at which 10
percent, 50 percent, and 90 percent of individuals exposed are assumed
to produce a behavioral response. For many marine mammals, including
pinnipeds, these response rates were set at sound pressure levels (SPL)
of 140, 160, and 180 dB, respectively.
We have evaluated these thresholds and determined that the Level B
harassment threshold of 120 dB for nonimpulsive noise is not applicable
to sea otters. The 120-dB threshold is
[[Page 59756]]
based on studies in which gray whales (Eschrichtius robustus) were
exposed to experimental playbacks of industrial noise (Malme et al.
1983; Malme and Miles 1983). During these playback studies, southern
sea otter responses to industrial noise were also monitored (Riedman
1983, 1984). Gray whales exhibited avoidance to industrial noise at the
120-dB threshold; however, there was no evidence of disturbance
reactions or avoidance in southern sea otters. Thus, given the
different range of frequencies to which sea otters and gray whales are
sensitive, the NMFS 120-dB threshold based on gray whale behavior is
not appropriate for predicting sea otter behavioral responses,
particularly for low-frequency sound.
Based on the lack of sea otter disturbance response or any other
reaction to the playback studies from the 1980s, as well as the absence
of a clear pattern of disturbance or avoidance behaviors attributable
to underwater sound levels up to about 160 dB resulting from low-
frequency broadband noise, we assume 120 dB is not an appropriate
behavioral response threshold for sea otters exposed to continuous
underwater noise.
Based on the best available scientific information about sea otters
and closely related marine mammals when sea otter data are limited, the
FWS has set 160 dB of received underwater sound as a threshold for
Level B take by disturbance for sea otters for this IHA. Exposure to
in-water noise levels between 125 Hz and 38 kHz that are greater than
160 dB--for both impulsive and nonimpulsive sound sources--will be
considered by the FWS as Level B harassment. Thresholds for Level A
harassment (which entails the potential for injury) for in-water sounds
between 125 Hz and 38 kHz will be 232 dB peak or 203 dB SEL for
impulsive sounds and 219 dB SEL for continuous sounds (table 1).
Airborne Sounds
The NMFS (2018) guidance neither addresses thresholds for
preventing injury or disturbance from airborne noise, nor provides
thresholds for avoidance of Level B harassment. Conveyance of
underwater noise into the air is of little concern since the effects of
pressure release and interference at the water's surface reduce
underwater noise transmission into the air. For activities that create
both in-air and underwater sounds, we will estimate take based on
parameters for underwater noise transmission. Considering sound energy
travels more efficiently through water than through air, this
estimation will also account for exposures to sea otters at the
surface.
Table 1--Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS) Thresholds Established by Southall
et al. (2019) Through Modeling and Extrapolation for ``Other Marine Carnivores,'' Which Include Sea Otters *
----------------------------------------------------------------------------------------------------------------
TTS PTS
-----------------------------------------------------------------------------------
nonimpulsive impulsive nonimpulsive impulsive
-----------------------------------------------------------------------------------
SELCUM SELCUM Peak SPL SELCUM SELCUM Peak SPL
----------------------------------------------------------------------------------------------------------------
Air......................... 157 146 170 177 161 176
Water....................... 199 188 226 219 203 232
----------------------------------------------------------------------------------------------------------------
* Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure
level (SELCUM dB re 20 micropascal ([mu]Pa) in air and SELCUM dB re 1 [mu]Pa in water) for impulsive and
nonimpulsive sounds, and unweighted peak sound pressure level (SPL) in air (dB re 20[mu]Pa) and water (dB
1[mu]Pa) (impulsive sounds only).
Evidence From Sea Otter Studies
Individual sea otters in Passage Canal will likely show a range of
responses to noise from pile-driving activities. Some sea otters will
likely dive, show startle responses, change direction of travel, or
prematurely surface. Sea otters reacting to pile-driving activities may
divert time and attention from biologically important behaviors, such
as feeding and nursing pups. Sea otter responses to disturbance can
result in energetic costs, which increases the amount of prey required
by sea otters (Barrett 2019). This increased prey consumption may
impact sea otter prey availability and cause sea otters to spend more
time foraging and less time resting (Barrett 2019). Some sea otters may
abandon the project area and return when the disturbance has ceased.
Based on the observed movement patterns of sea otters (Lensink 1962;
Kenyon 1969, 1981; Garshelis and Garshelis 1984; Riedman and Estes
1990; Tinker and Estes 1996), we expect some individuals will respond
to pile-driving activities by dispersing to nearby areas of suitable
habitat; however other sea otters, especially territorial adult males,
will not be displaced.
Additional information on the evidence from studies about how sea
otters may be affected by sound can be found in the supplemental
information to this document (available as described above in
ADDRESSES).
Consequences of Disturbance
Information on the consequences of disturbance to sea otters can be
found in the supplemental information to this document (available as
described above in ADDRESSES).
Vessel Activities
Vessel activity during the project includes the transit of three
barges for materials and construction, all of which will remain on
site, mostly stationary, to support the work; additionally, two skiffs
will be used during the project: one for transporting workers short
distances to the crane barge and the other for marine mammal monitoring
during pile driving. Vessels will not be used extensively or over a
long duration during the planned work; therefore, we do not anticipate
that sea otters will experience changes in behavior indicative of
tolerance or habituation.
Additional information on vessel activities can be found in the
supplemental information to this document (available as described above
in ADDRESSES).
Effects on Sea Otter Habitat and Prey
Information on the potential impacts of the specified activities on
sea otter prey species can be found in the supplemental information to
this document (available as described above in ADDRESSES).
Potential Impacts of the Specified Activities on Subsistence Uses
The planned specified activities will occur near marine subsistence
harvest areas used by Alaska Native peoples from Whittier and the
surrounding areas. The majority of sea otter harvest in this area
occurs more than 3.2
[[Page 59757]]
kilometers (km) (2 miles [mi]) outside of Whittier. Since 2012, there
have been 75 sea otters harvested in the Whittier area, and most of
those were taken prior to 2017. From 2018 through 2021, only eight sea
otters were harvested from the Whittier area.
The planned project would occur within the Whittier city limits,
where firearm use is prohibited. The area potentially affected by the
planned project does not significantly overlap with current subsistence
harvest areas. Construction activities will not preclude access to
hunting areas or interfere in any way with individuals wishing to hunt.
Despite no conflict with subsistence use being anticipated, the FWS
will conduct outreach with potentially affected communities to see
whether there are any questions, concerns, or potential conflicts
regarding subsistence use in those areas. If any conflicts are
identified in the future, TMC will develop a plan of cooperation
specifying the steps necessary to minimize any effects the project may
have on subsistence harvest.
Estimated Take
Definitions of Incidental Take Under the Marine Mammal Protection Act
Below we provide definitions of potential types of take of northern
sea otters. The FWS does not anticipate and is not proposing to
authorize lethal take as a part of this proposed IHA, nor did the
applicant request authorization of lethal take; however, the
definitions of these take types are provided for context and
background.
Lethal Take--Human activity may result in biologically significant
impacts to northern sea otters. In the most serious interactions, human
actions can result in the mortality of sea otters.
Level A Harassment--Human activity may result in the injury of sea
otters. Level A harassment for nonmilitary readiness activities is
defined as any act of pursuit, torment, or annoyance that has the
potential to injure a marine mammal or marine mammal stock in the wild.
Level B Harassment--Level B harassment for nonmilitary readiness
activities means any act of pursuit, torment, or annoyance that has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behaviors or activities, including, but not
limited to, migration, breathing, nursing, feeding, or sheltering.
Human-caused changes in behavior that disrupt biologically significant
behaviors or activities for the affected animal indicate take by Level
B harassment under the MMPA.
The FWS has identified the following sea otter behaviors as
indicative of possible Level B harassment:
<bullet> Swimming away at a fast pace on belly (i.e., porpoising);
<bullet> Repeatedly raising the head vertically above the water to
get a better view (spyhopping) while apparently agitated or while
swimming away;
<bullet> In the case of a pup, repeatedly spyhopping while hiding
behind and holding onto its mother's head;
<bullet> Abandoning prey or feeding area;
<bullet> Ceasing to nurse and/or rest (applies to dependent pups);
<bullet> Ceasing to rest (applies to independent animals);
<bullet> Ceasing to use movement corridors;
<bullet> Ceasing mating behaviors;
<bullet> Shifting/jostling/agitation in a raft so that the raft
disperses;
<bullet> Sudden diving of an entire raft; or
<bullet> Flushing animals off a haulout.
This list is not meant to encompass all possible behaviors; other
behavioral responses may also be indicative of Level B harassment.
Relatively minor changes in behavior such as increased vigilance or a
short-term change in direction of travel are not likely to disrupt
biologically important behavioral patterns, and the FWS does not view
such minor changes in behavior as indicative of Level B harassment.
Calculating Take
We assumed all animals exposed to underwater sound levels that meet
the acoustic exposure criteria defined above in Exposure Thresholds
will experience take by Level A harassment or Level B harassment due to
exposure to underwater noise. Spatially explicit zones of
ensonification were established around the planned construction
location to estimate the number of otters that may be exposed to these
sound levels. We determined the number of otters present in the
ensonification zones using density information generated by Esslinger
et al. (2021).
The project can be divided into four major components: DTH
drilling, vibratory drilling, pile driving using an impact driver, and
skiff use to support construction. Each of these components will
generate a different type of in-water noise. Vibratory drilling and the
use of skiffs will produce nonimpulsive or continuous noise; impact
driving will produce impulsive noise; and DTH drilling is considered to
produce both impulsive and continuous noise (NMFS 2020).
The level of sound anticipated from each project component was
established using recorded data from several sources listed in tables 2
through 5. We used the empirical data from those proxy projects with
the NMFS Technical Guidance and User Spreadsheet (NMFS 2018, 2020) to
determine the distance at which sound levels would attenuate to Level A
harassment thresholds (table 1). To estimate the distances at which
sounds would attenuate to Level B harassment thresholds (table 1), we
used the data from the proxy projects with the NMFS-recommended
transmission loss coefficient of 15 for coastal pile-driving activities
in a practical spreading loss model (NMFS 2020) to determine the
distance at which sound levels attenuate to 160 dB re 1 [mu]Pa. The
weighting factor adjustment included in the NMFS user spreadsheet
accounts for sounds created in portions of an organism's hearing range
where they have less sensitivity. We used the weighting factor
adjustment for otariid pinnipeds as they are the closest available
physiological and anatomical proxy for sea otters. The spreadsheet also
incorporates a transmission loss coefficient, which accounts for the
reduction in sound level outward from a sound source. We used the NMFS-
recommended transmission loss coefficient of 15 for coastal pile-
driving activities to indicate practical spread (NMFS 2020).
We calculated the harassment zones for DTH drilling with input from
NMFS. The SPLs produced by DTH drilling were provided by NMFS in 2022
via correspondence with Solstice Alaska Consulting, who created the
application for this IHA on behalf of TMC, as well as from the NMFS
proposed IHA for this project in 2023. We then used the provided SPLs
with the NMFS Technical Guidance and User Spreadsheet (NMFS 2018, 2020)
to determine the distance at which these sounds would attenuate to
Level A harassment thresholds. To estimate the distances at which
sounds would attenuate to Level B harassment thresholds, we used the
provided SPLs with a NMFS-recommended transmission loss coefficient of
15 for coastal pile-driving activities in a practical spreading loss
model (NMFS 2020) to determine the distance at which sound levels
attenuate to 160 dB re 1 [mu]Pa. To ensure the most conservative
harassment thresholds, peak SPL of 194 dB re 1 [mu]Pa (Heyvaert and
Reyff 2021) was included in the calculations of Level B harassment
thresholds for DTH pile driving. However, due to the differences in how
PTS and TTS thresholds are calculated, as well as limited data of
underwater
[[Page 59758]]
SPLs from DTH drilling, the resultant Level A isopleths for DTH
installation of 122-cm (48-in) steel piles are larger than the Level B
isopleths.
Table 2--Summary of Sound Level, Timing of Sound Production, Distance From Sound Source to Below Level A
Harassment and Level B Harassment Thresholds, Days of Impact, Sea Otters in Level A and Level B Harassment
Ensonification Area, and Total Otters Expected To Be Harassed Through Behavioral Disturbance by Vibratory
Drilling
----------------------------------------------------------------------------------------------------------------
91-cm (36-in) 91-cm (36-in)
Pile size (temporary)- (temporary)- 91-cm (36-in) 122-cm (48-in)
installation removal (permanent) (permanent)
----------------------------------------------------------------------------------------------------------------
Total number of piles.......... 15................. 15................ 7................. 8.
----------------------------------------------------------------------------------------------------------------
Sound level.................... 166 dB re 1[mu]Pa at 10 m (RMS) 168.2 dB re
1[mu]Pa at 10 m
(RMS).
----------------------------------------------------------------------------------------------------------------
Source......................... NAVFAC \a\ 2015 Austin et al.
2016.
----------------------------------------------------------------------------------------------------------------
Timing per pile................ 10 minutes/pile.... 10 minutes/pile... 15 minutes/pile... 15 minutes/pile.
Maximum number of piles per day 4.................. 4................. 4................. 2.
Maximum number of days of 4.................. 4................. 2................. 4.
activity.
----------------------------------------------------------------------------------------------------------------
Sea otter density.............. 2.03 sea otters/km\2\
----------------------------------------------------------------------------------------------------------------
Distance to below Level A 0.5 meters......... 0.5 meters........ 0.6 meters........ 0.6 meters.
harassment threshold.
Level A area (km\2\)........... 0.000001........... 0.000001.......... 0.000001.......... 0.000001.
Potential sea otters affected 0.000002........... 0.000002.......... 0.000002.......... 0.000002.
by Level A sound per day.
Potential sea otters affected 0.................. 0................. 0................. 0.
by Level A sound per day
(rounded).
----------------------------------------------------------------------------------------------------------------
Total potential Level A 0.................. 0................. 0................. 0.
harassment events.
----------------------------------------------------------------------------------------------------------------
Distance to below Level B 25 meters.......... 25 meters......... 25 meters......... 35 meters.
harassment threshold.
Level B area (km\2\)........... 0.002.............. 0.0020............ 0.0020............ 0.0038.
Potential sea otters affected 0.0040............. 0.0040............ 0.004............. 0.0078.
by Level B sound per day.
Potential sea otters affected 0.................. 0................. 0................. 0.
by Level B sound per day
(rounded).
----------------------------------------------------------------------------------------------------------------
Total potential Level B 0.................. 0................. 0................. 0.
harassment events.
----------------------------------------------------------------------------------------------------------------
\a\ Naval Facilities Engineering Command.
Table 3--Summary of Sound Level, Timing of Sound Production, Distance
From Sound Source to Below Level A Harassment and Level B Harassment
Thresholds, Days of iMpact, Sea Otters in Level A and Level B Harassment
Ensonification Area, and Total Otters Expected To Be Harassed Through
Behavioral Disturbance by Impact Pile Driving
------------------------------------------------------------------------
91-cm (36-in) 122-cm (48-in)
Pile size (permanent) (permanent)
------------------------------------------------------------------------
Total number of piles........... 7................. 8.
Sound level..................... 184 dB (SEL)/192 186.7 dB (SEL)/
dB (RMS)/211 dB 198.6 dB (RMS)/
(peak) re 1[mu]Pa 212 dB (peak) re
at 10 m. 1[mu]Pa at 10 m.
Source.......................... NAVFAC 2015....... Austin et al.
2016.
Timing per pile................. 45 minutes/pile; 60 minutes/pile;
1,800 strikes/ 2,400 strikes/
pile. pile.
Maximum number piles per day.... 4................. 2.
Maximum number of days of 2................. 4.
activity.
------------------------------------------------------------------------
Sea otter density............... 2.03 sea otters/km\2\.
------------------------------------------------------------------------
Distance to below Level A 169.2 meters...... 195.4 meters.
harassment threshold.
Level A area (km\2\)............ 0.0718............ 0.1199.
Potential sea otters affected by 0.1458............ 0.2435.
Level A sound per day.
Potential sea otters affected by 1................. 1.
Level A sound per day (rounded).
------------------------------------------------------------------------
Total potential Level A 2................. 4.
harassment events.
------------------------------------------------------------------------
Distance to below Level B 1,359 meters...... 3,744 meters.
harassment threshold.
Level B area (km\2\)............ 1.9161............ 7.8846.
Potential sea otters affected by 3.8897............ 16.0058
Level B sound per day.
Potential sea otters affected by 4................. 16.
Level B sound per day (rounded).
------------------------------------------------------------------------
Total potential Level B 8................. 64.
harassment events.
------------------------------------------------------------------------
[[Page 59759]]
Table 4--Summary of Sound Level, Timing of Sound Production, Distance From Sound Source to Below Level A
Harassment and Level B Harassment Thresholds, Days of Impact, Sea Otters in Level A and Level B Harassment
Ensonification Area, and Total Otters Expected To Be Harassed Through Behavioral Disturbance by Down-the-Hole
Drilling
----------------------------------------------------------------------------------------------------------------
91-cm (36-in) 91-cm (36-in) 122-cm (48-in)
Pile size (temporary) (permanent) (permanent)
----------------------------------------------------------------------------------------------------------------
Total number of piles............... 10 (installation only).. 7...................... 8.
----------------------------------------------------------------------------------------------------------------
Sound level......................... 164 dB (SEL)/174 dB (RMS)/194 (peak) re 1[mu]Pa 171 dB (SEL)/174 (RMS)/
at 10 m. 194 (peak) dB re
1[mu]Pa at 10 m.
----------------------------------------------------------------------------------------------------------------
Source.............................. Reyff and Heyvaert 2019; Reyff 2020; Denes et al. SolsticeAK 2022;
2019; Heyvaert and Reyff 2021; NMFS 2023. Heyvaert and Reyff
2021; NMFS 2023.
----------------------------------------------------------------------------------------------------------------
Timing per pile..................... 60 minutes/pile......... 150 minutes/pile....... 150 minutes/pile.
Maximum number piles per day........ 4....................... 2...................... 2.
Maximum number of days of activity.. 3....................... 4...................... 4.
----------------------------------------------------------------------------------------------------------------
Sea otter density................... 2.03 sea otters/km\2\.
----------------------------------------------------------------------------------------------------------------
Distance to below Level A harassment 57.9 meters............. 67.1 meters............ 196.6 meters.\a\
threshold.
Level A area (km\2\)................ 0.0105.................. 0.0141................. 0.1214.
Potential sea otters affected by 0.0214.................. 0.0287................. 0.2465.
Level A sound per day.
Potential sea otters affected by 1....................... 1...................... 1.
Level A sound per day (rounded).
----------------------------------------------------------------------------------------------------------------
Total potential Level A 3....................... 4...................... 4.
harassment events.
----------------------------------------------------------------------------------------------------------------
Distance to below Level B harassment 85.8 meters............. 85.8 meters............ 85.8 meters.\a\
threshold.
Level B area (km\2\)................ 0.0231.................. 0.0231................. 0.0231.
Potential sea otters affected by 0.0469.................. 0.0469................. 0.0469.
Level B sound per day.
Potential sea otters affected by 1....................... 1...................... 1.
Level B sound per day (rounded).
----------------------------------------------------------------------------------------------------------------
Total potential Level B 3....................... 4...................... 4.
harassment events.
----------------------------------------------------------------------------------------------------------------
\a\ Due to differences in how PTS and TTS thresholds are calculated, the Level A isopleths are larger than the
Level B isopleths.
Table 5--Summary of Sound Level, Timing of Sound Production, Distance
From Sound Source to Below Level A Harassment and Level B Harassment
Thresholds, Days of Impact, Sea Otters in Level A and Level B Harassment
Ensonification Area, and Total Otters Expected To Be Harassed Through
Behavioral Disturbance by Use of Skiffs
------------------------------------------------------------------------
Worker transit
Sound source Monitoring skiff skiff
------------------------------------------------------------------------
Sound level..................... 175 dB (RMS) re 175 dB (RMS) re
1[mu]Pa at 1 m. 1[mu]Pa at 1 m.
------------------------------------------------------------------------
Source.......................... Richardson et al. 1995; Kipple and
Gabriele 2007.
------------------------------------------------------------------------
Number of days of vessel use.... 31................ 31.
------------------------------------------------------------------------
Sea otter density............... 2.03 sea otters/km\2\.
------------------------------------------------------------------------
Distance to below Level A 0 meters.......... 0 meters.
harassment threshold.
Level A area (km\2\)............ 0................. 0.
Potential sea otters affected by 0................. 0.
Level A sound per day.
Potential sea otters affected by 0................. 0.
Level A sound per day (rounded).
------------------------------------------------------------------------
Total potential Level A 0................. 0.
harassment events.
------------------------------------------------------------------------
Distance to below Level B 10 meters......... 10 meters.
harassment threshold.
Level B area (km\2\)............ 0.2832............ 0.0095.
Potential sea otters affected by 0.5748............ 0.0192.
Level B sound per day.
Potential sea otters affected by 1................. 1.
Level B sound per day (rounded).
------------------------------------------------------------------------
[[Page 59760]]
Total potential Level B 31................ 31.
harassment events.
------------------------------------------------------------------------
Sound levels for all sources are unweighted and given in dB re 1
[mu]Pa. Nonimpulsive sounds are in the form of mean maximum root mean
square (RMS) SPL as it is more conservative than SEL<INF>CUM</INF> or
peak SPL for these activities. Impulsive sound sources are in the form
of SEL for a single strike.
To determine the number of sea otters that may experience in-water
sounds >160 dB re 1[mu]Pa due to pile driving, we multiplied the area
ensonified to >160 dB re 1[mu]Pa by the density of animals (2.03 sea
otters per square kilometer (km\2\)) derived from surveys conducted of
Prince William Sound (Esslinger et al. 2021). We applied the same
methodology to determine the number of sea otters that may experience
sounds capable of causing PTS. The number of sea otters expected to be
exposed to such sound levels can be found in tables 2 through 5. To
calculate the area ensonified for each type of pile-driving activity,
the coordinates of the piles were mapped in ArcGIS Pro. We used a
representative pile of each size around which to map the Level A
harassment and Level B harassment zones. We chose representative piles
that were farthest from shore so that the zones that are intercepted by
land have the largest in-water areas possible. The majority of these
radii are small enough that their defined circles will fall entirely in
the water, and in these instances, the area was calculated as [pi]r\2\.
The exceptions are the Level A and Level B zones generated by impact
pile driving the 91-cm (36-in) permanent piles as well as the Level B
zone generated by impact pile driving the 122-cm (48-in) piles; for
these, we used ArcGIS Pro to map and calculate the area of the water
ensonified by those activities.
The area ensonified by the worker transit skiff was estimated by
multiplying the vessel's anticipated daily track length by twice the
160 dB radius plus [pi]r\2\ to account for the rounded ends of the
track line. It was estimated that the distance of each trip would be no
more than 457.2 m (1,500 ft). The worker transit skiff transports crew
between shore and the work platform. It will be in use the same days
that pile driving occurs but is not expected to be used while piles are
being driven.
The monitoring skiff will travel in a triangle of perimeter
approximately 7 km (4.3 mi) between Emerald Island, the north shore of
Passage Canal, and Gradual Point during pile driving activities, but
outside the largest Level B harassment threshold. To estimate the area
ensonified by the monitoring skiff, we used ArcGIS Pro to plot the
points of the triangle, map the track line between those points, and
apply a buffer of 10 m (33 ft; the 160-dB radius) on either side of the
track line.
We assumed that the different types of pile-driving activities
would occur sequentially and that the total number of days of work
would equal the sum of the number of days required to complete each
type of pile-driving activity. While it is possible that on some days
more than one type of activity will take place, which would reduce the
number of days of exposure within a year, we cannot know this
information in advance. As such, the estimated number of days and,
therefore, exposures per year is the maximum possible for the planned
work. Where the number of exposures expected per day was zero to three
or more decimal places (i.e., <0.00X), the number of exposures per day
was assumed to be zero.
In order to minimize exposure of sea otters to sounds above Level A
harassment thresholds, TMC will implement shutdown zones ranging from
10 to 200 m (33 to 656 ft), based on the pile size and type of pile
driving or marine construction activity, where operations will cease
should a sea otter enter or approach the specified zone. Soft-start and
zone clearance prior to startup will also limit the exposure of sea
otters to sound levels that could cause PTS. However, TMC has
requested, and the FWS proposes to authorize, small numbers of take by
Level A harassment during impact pile driving and DTH drilling.
Although sea otters are non-migratory, they typically move amongst
focal areas within their home ranges to rest and forage (Garshelis and
Garshelis 1984; Laidre et al. 2009). It is possible that, given the
large variability in individual home range sizes and the potential for
up to daily movement in and out of foraging or resting areas, different
individual sea otters could be found within the ensonification zone
each day of the project. Thus, the FWS conservatively assumes that the
162 estimated harassment events may impact up to 162 different sea
otters.
Critical Assumptions
We estimate that 145 takes of 145 sea otters by Level B harassment
and 17 takes of 17 sea otters by Level A harassment may occur due to
TMC's planned cruise ship dock construction activities. In order to
conduct this analysis and estimate the potential amount of take by
harassment, several critical assumptions were made.
Level B harassment is equated herein with behavioral responses that
indicate harassment or disturbance. There is likely a portion of
animals that respond in ways that indicate some level of disturbance
but do not experience biologically significant consequences.
We used the sea otter density for the Whittier area from surveys
and analyses conducted by Esslinger et al. (2021). Methods and
assumptions for these surveys can be found in the original publication.
We used sound source verification from recent pile-driving
activities in a number of locations within and beyond Alaska to
generate sound level estimates for construction activities.
Environmental conditions in these locations, including water depth,
substrate, and ambient sound levels are similar to those in the project
location, but not identical. Further, estimation of ensonification
zones were based on sound attenuation models using a practical
spreading loss model. These factors may lead to actual sound values
differing slightly from those estimated here.
Finally, the pile-driving activities described here will also
create in-air noise. Because sea otters spend over half of their day
with their heads above water (Esslinger et al. 2014), they will be
exposed to an increase in-air noise from construction equipment.
However, we have calculated Level B harassment with the assumption that
an individual may be harassed only one time per 24-
[[Page 59761]]
hour period, and underwater sound levels will be more disturbing and
extend farther than in-air noise. Thus, while sea otters may be
disturbed by noise both in-air and underwater, we have relied on the
more conservative underwater estimates.
Sum of Harassment From All Sources
The applicant plans to conduct pile driving and marine construction
activities in Whittier, Alaska, over the course of a year from the date
of issuance of the IHA. A summary of total estimated take during the
project by source is provided in table 6.
Table 6--Total Estimated Takes by Source of Level A Harassment and Level B Harassment of Sea Otters
----------------------------------------------------------------------------------------------------------------
Sea otters Total takes of Sea otters Total takes of
Number of days exposed per sea otters by exposed per sea otters by
Source of activity day to Level A Level A day to Level B Level B
harassment harassment harassment harassment
----------------------------------------------------------------------------------------------------------------
Vibratory drilling:
91-cm (36-in) (temporary)-- 4 0 0 0 0
installation...............
91-cm (36-in) (temporary)-- 4 0 0 0 0
removal....................
91-cm (36-in) (permanent)... 2 0 0 0 0
122-cm (48-in) (permanent).. 4 0 0 0 0
Impact drilling:
91-cm (36-in) (permanent)... 2 1 2 4 8
122-cm (48-in) (permanent).. 4 1 4 16 64
Down-the-hole drilling:
91-cm (36-in) (temporary)-- 3 1 3 1 3
installation...............
91-cm (36-in) (permanent)... 4 1 4 1 4
122-cm (48-in) (permanent).. 4 1 4 1 4
Skiff use:
Monitoring skiff............ 31 0 0 1 31
Worker transit skiff........ 31 0 0 1 31
-------------------------------------------------------------------------------
Totals...................... 93 5 17 25 145
----------------------------------------------------------------------------------------------------------------
Over the course of the project, we estimate 145 instances of take
by Level B harassment of northern sea otters from the Southcentral
Alaska stock due to behavioral responses and/or TTS associated with
noise exposure. Although multiple instances of Level B harassment of
individual sea otters are possible, these events are unlikely to have
significant consequences for the health, reproduction, or survival of
affected animals and therefore would not rise to the level of an injury
or Level A harassment.
The use of soft-start procedures, zone clearance prior to startup,
and shutdown zones is likely to decrease both the number of sea otters
exposed to sounds above Level A harassment thresholds and the exposure
time of any sea otters venturing into a Level A harassment zone. This
reduces the likelihood of losses of hearing sensitivity that might
impact the health, reproduction, or survival of affected animals.
Despite the implementation of mitigation measures, it is anticipated
that some sea otters will experience Level A harassment via exposure to
underwater sounds above threshold criteria during impact and DTH pile-
driving activities. Due to sea otters' small body size and low profile
in the water, as well as the relatively large size of the Level A
harassment zone associated with these activities, we anticipate that
sea otters will at times avoid detection before entering Level A
harassment zones for those activities. We anticipate that protected
species observers (PSO) will be able to reliably detect and prevent
take by Level A harassment of sea otters up to 10 m away; conversely,
we anticipate that at distances greater than 10 m, sea otters will at
times avoid detection. Throughout the project, we estimate 17 instances
of take by Level A harassment of sea otters.
Determinations and Findings
Sea otters exposed to sound from the specified activities are
likely to respond with temporary behavioral modification or
displacement. The specified activities could temporarily interrupt the
feeding, resting, and movement of sea otters. Because activities will
occur during a limited amount of time and in a localized region, the
impacts associated with the project are likewise temporary and
localized. The anticipated effects are short-term behavioral reactions
and displacement of sea otters near active operations.
Sea otters that encounter the specified activity may exert more
energy than they would otherwise, due to temporary cessation of
feeding, increased vigilance, and retreating from the project area. We
expect that affected sea otters will tolerate this exertion without
measurable effects on health or reproduction. Most of the anticipated
takes will be due to short-term Level B harassment in the form of TTS,
startling reactions, or temporary displacement. While mitigation
measures incorporated into TMC's request will reduce occurrences of
Level A harassment to the extent practicable, a small number of take by
Level A harassment would be authorized for impact and DTH pile-driving
activities, which have Level A harassment zone radii ranging in size
from 57.9 to 196.6 m (190 to 645 ft).
With the adoption of the mitigation measures incorporated in TMC's
request and required by this proposed IHA, anticipated take was
reduced. Those mitigation measures are further described below.
Small Numbers
To assess whether the authorized incidental taking would be limited
to ``small numbers'' of marine mammals, the FWS uses a proportional
approach that considers whether the estimated number of marine mammals
to be subjected to incidental take is small relative to the population
size of the species or stock. Here, predicted levels of take were
determined based on the estimated density of sea otters in the project
area and ensonification zones developed using empirical evidence from
similar geographic areas.
We estimate that TMC's specified activities in the specified
geographic region will take no more than 145 takes of 145 sea otters by
Level B harassment and 17 takes of 17 sea otters by Level A harassment
during the 1-year period of this proposed IHA (see Sum of Harassment
from All Sources). Take of 162 animals is 0.7 percent of the best
available estimate of the current Southcentral Alaska stock size of
21,617 animals (Esslinger et al. 2021) ((162/21,617)x100[ap]0.7) and
represents a
[[Page 59762]]
``small number'' of sea otters of that stock.
Negligible Impact
We propose a finding that any incidental take by harassment
resulting from the specified activities cannot be reasonably expected
to, and is not reasonably likely to, adversely affect the sea otter
through effects on annual rates of recruitment or survival and will,
therefore, have no more than a negligible impact on the Southcentral
Alaska stock of northern sea otters. In making this finding, we
considered the best available scientific information, including the
biological and behavioral characteristics of the species, the most
recent information on species distribution and abundance within the
area of the specified activities, the current and expected future
status of the stock (including existing and foreseeable human and
natural stressors), the potential sources of disturbance caused by the
project, and the potential responses of marine mammals to this
disturbance. In addition, we reviewed applicant-provided materials,
information in our files and datasets, published reference materials,
and species experts.
Sea otters are likely to respond to planned activities with
temporary behavioral modification or temporary displacement. These
reactions are not anticipated to have consequences for the long-term
health, reproduction, or survival of affected animals. Most animals
will respond to disturbance by moving away from the source, which may
cause temporary interruption of foraging, resting, or other natural
behaviors. Affected animals are expected to resume normal behaviors
soon after exposure with no lasting consequences. Sea otters may move
in and out of the project area during pile driving activities, leading
to as many as 162 individuals experiencing one day of exposure.
However, it is possible that an individual may enter the ensonification
area more than once during the project. At most, if the same sea otter
enters the ensonification area every day that pile driving occurs, the
sea otter would be exposed to pile driving and marine construction
noise for up to 31 days. However, injuries (i.e., Level A harassment or
PTS) due to chronic sound exposure are estimated to occur at a longer
time scale (Southall et al. 2019). The area that will experience noise
greater than Level B thresholds due to pile driving is small (less than
0.13 km\2\), and an animal that may be disturbed could escape the noise
by moving to nearby quiet areas. Further, sea otters spend over half of
their time above the surface during the summer months (Esslinger et al.
2014), and likely no more than 70 percent of their time foraging during
winter months (Gelatt et al. 2002); thus, their ears will not be
exposed to continuous noise, and the amount of time it may take for
permanent injury is considerably longer than that of mammals primarily
under water. Some animals may exhibit some of the stronger responses
typical of Level B harassment, such as fleeing, interruption of
feeding, or flushing from a haulout. These responses could have
temporary biological impacts for affected individuals but are not
anticipated to result in measurable changes in survival or
reproduction.
The total number of animals affected, and severity of impact is not
sufficient to change the current population dynamics at the stock
scale. Although the specified activities may result in approximately
162 incidental takes of up to 162 sea otters from the Southcentral
Alaska stock, we do not expect this level of harassment to affect
annual rates of recruitment or survival or result in adverse effects on
the stock.
Currently, the best available scientific information indicates that
the density of sea otters in the project area is 2.03 sea otters/km\2\
(Esslinger et al. 2021). However, during similar marine construction
and pile-driving activities in Whittier under an existing IHA, PSOs
collected data which indicate that the proposed project activities may
be less impactful than estimated (table 7). No recorded takes by Level
A harassment occurred during similar work in Whittier between May 2023
and February 2024, and only 5 takes by Level B harassment occurred over
those 10 months.
Table 7--Total Numbers of Observations, Individuals, and Takes by Level A Harassment and Level B Harassment of
Sea Otters Under the Initial IHA
----------------------------------------------------------------------------------------------------------------
Number of Number of Number of
Year Month Number of individual sea takes by Level takes by Level
sightings otters A harassment B harassment
----------------------------------------------------------------------------------------------------------------
2023.......................... May............. 1 6 0 0
June............ 1 1 0 0
July............ 1 1 0 0
August.......... 5 5 0 0
September....... 13 13 0 3
October......... 18 22 0 2
November........ 7 11 0 0
December........ 9 15 0 0
2024.......................... January......... 6 3 0 0
February........ 1 1 0 0
---------------------------------------------------------------
Total..................... ................ 62 78 0 5
----------------------------------------------------------------------------------------------------------------
Our proposed finding of negligible impact applies to incidental
take associated with the specified activities as mitigated by the
avoidance and minimization measures identified in TMC's mitigation and
monitoring plan. These mitigation measures are designed to minimize
interactions with and impacts to sea otters. These measures and the
monitoring and reporting procedures are required for the validity of
our finding and are a necessary component of the proposed IHA. For
these reasons, we propose a finding that the specified project will
have a negligible impact on the Southcentral Alaska stock of northern
sea otters.
Least Practicable Adverse Impacts
We find that the mitigation measures required by this proposed IHA
will affect the least practicable adverse impacts on the stocks from
any incidental take likely to occur in association with the specified
activities. In making this finding, we considered the biological
characteristics of sea otters, the nature of the specified activities,
the potential effects of the activities on sea otters, the documented
impacts of similar activities on sea otters, and alternative mitigation
measures.
In evaluating what mitigation measures are appropriate to ensure
the
[[Page 59763]]
least practicable adverse impact on species or stocks and their
habitat, as well as subsistence uses, we considered the manner and
degree to which the successful implementation of the measures are
expected to achieve this goal. We considered the nature of the
potential adverse impact being mitigated (likelihood, scope, range),
the likelihood that the measures will be effective if implemented, and
the likelihood of effective implementation. We also considered the
practicability of the measures for applicant implementation (e.g.,
cost, impact on operations). We assessed whether any additional,
practicable requirements could be implemented to further reduce
effects, but did not identify any.
To reduce the potential for disturbance from acoustic stimuli
associated with the activities, TMC will implement mitigation measures,
including the following:
<bullet> Using the smallest diameter piles practicable while
minimizing the overall number of piles;
<bullet> Using a project design that does not include dredging or
blasting;
<bullet> Using pile caps made of high-density polyethylene or
ultra-high-molecular-weight polyethylene softening materials during
impact pile driving;
<bullet> Minimizing the use of the impact hammer to the extent
possible by using a vibratory hammer to advance piles as deeply as
possible;
<bullet> Employing an 18-m (60-ft) deep bubble curtain during all
impact pile driving as well as during all pile-driving activities in
less than 18 m (60 ft) of water to reduce noise impacts;
<bullet> Development of a marine mammal monitoring and mitigation
plan;
<bullet> Establishment of shutdown and monitoring zones;
<bullet> Visual mitigation monitoring by designated PSOs;
<bullet> Site clearance before startup;
<bullet> Soft-start procedures; and
<bullet> Shutdown procedures.
Impact on Subsistence Use
The project will not preclude access to harvest areas or interfere
with the availability of sea otters for harvest. Additionally, the
planned cruise ship berth and associated facilities are located within
the City of Whittier, where firearm use is prohibited. We therefore
propose a finding that TMC's anticipated harassment will not have an
unmitigable adverse impact on the availability of any stock of northern
sea otters for taking for subsistence uses. In making this proposed
finding, we considered the timing and location of the planned
activities and the timing and location of subsistence harvest
activities in the project area.
Monitoring and Reporting
The purposes of the monitoring requirements are to document and
provide data for assessing the effects of specified activities on sea
otters; to ensure that take is consistent with that anticipated in the
small numbers, negligible impact, and subsistence use analyses; and to
detect any unanticipated effects on the species. Monitoring plans
include steps to document when and how sea otters are encountered and
their numbers and behaviors during these encounters. This information
allows the FWS to measure encounter rates and trends and to estimate
numbers of animals potentially affected. To the extent possible,
monitors will record group size, age, sex, reaction, duration of
interaction, and closest approach to the project activity.
As proposed, monitoring activities will be summarized and reported
in formal reports. TMC must submit monthly reports for all months
during which noise-generating work takes place as well as a final
monitoring report that must submitted no later than 90 days after the
expiration of the IHA. We will require approval of the monitoring
results for continued operation under the IHA.
We find that these proposed monitoring and reporting requirements
to evaluate the potential impacts of planned activities will ensure
that the effects of the activities remain consistent with the rest of
the findings.
Required Determinations
National Environmental Policy Act
We have prepared a draft environmental assessment in accordance
with the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et
seq.). We have preliminarily concluded that authorizing the nonlethal,
incidental, unintentional take by Level B harassment of up to 145 takes
and by Level A harassment of up to 17 takes from the Southcentral
Alaska stock of northern sea otters in the specified geographic region
during the specified activities during the regulatory period would not
significantly affect the quality of the human environment and, thus,
preparation of an environmental impact statement for this proposed IHA
is not required by section 102(2) of NEPA or its implementing
regulations. We are accepting comments on the draft environmental
assessment as specified above in DATES and ADDRESSES.
Endangered Species Act
Under the Endangered Species Act (ESA; 16 U.S.C. 1536(a)(2)), all
Federal agencies are required to ensure the actions they authorize are
not likely to jeopardize the continued existence of any threatened or
endangered species or result in destruction or adverse modification of
critical habitat. The specified activities would occur entirely within
the range of the Southcentral Alaska stock of northern sea otters,
which is not listed as threatened or endangered under the ESA. The
authorization of incidental take of northern sea otters and the
measures included in the proposed IHA would not affect other listed
species or designated critical habitat.
Government-to-Government Consultation
It is our responsibility to communicate and work directly on a
Government-to-Government basis with federally recognized Alaska Native
Tribes and Alaska Native Claims Settlement Act (ANCSA) corporations in
developing programs for healthy ecosystems. We seek their full and
meaningful participation in evaluating and addressing conservation
concerns for protected species. It is our goal to remain sensitive to
Alaska Native culture, and to make information available to Alaska
Tribal organizations and communities. Our efforts are guided by the
following policies and directives:
(1) The Native American Policy of the Service (January 20, 2016);
(2) The Alaska Native Relations Policy (currently in draft form);
(3) Executive Order 13175 (January 9, 2000);
(4) Department of the Interior Secretary's Orders 3206 (June 5,
1997), 3225 (January 19, 2001), 3317 (December 1, 2011), and 3342
(October 21, 2016);
(5) The Alaska Government-to-Government Policy (a departmental
memorandum issued January 18, 2001); and
(6) the Department of the Interior's policies on consultation with
Alaska Native Tribes and organizations.
We have evaluated possible effects of the specified activities on
federally recognized Alaska Native Tribes and organizations. The FWS
has determined that, due to this project's locations and activities,
the Tribal organizations and communities near Whittier, Alaska, as well
as relevant Alaska Native Claims Settlement Act (ANCSA) corporations,
will not be impacted. Regardless, we will be reaching out to the Tribal
organizations and ANCSA corporations
[[Page 59764]]
to inform them of the availability of this proposed IHA and offer them
the opportunity to consult.
We invite continued discussion, either about the project and its
impacts or about our coordination and information exchange, throughout
the IHA process.
Paperwork Reduction Act
This rule does not contain any new collection of information that
requires approval by the Office of Management and Budget (OMB) under
the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). OMB has
previously approved the information collection requirements associated
with IHAs and assigned OMB Control Number 1018-0194 (expires August 31,
2026). An agency may not conduct or sponsor, and a person is not
required to respond to, a collection of information unless it displays
a currently valid OMB control number.
Proposed Authorization
We propose to authorize the nonlethal, incidental take by Level A
harassment and Level B harassment of 162 northern sea otters from the
Southcentral Alaska stock. Authorized take may be caused by pile
driving and marine construction activities conducted by TMC in
Whittier, Alaska, between July 19, 2024, and July 18, 2025. We do not
anticipate or authorize any lethal take to sea otters resulting from
these activities.
A. General Conditions for This IHA
(1) Activities must be conducted in the manner described in the
March 18, 2024, revised request from TMC for an IHA and in accordance
with all applicable conditions and mitigation measures. The taking of
sea otters whenever the required conditions, mitigation, monitoring,
and reporting measures are not fully implemented as required by the IHA
is prohibited. Failure to follow the measures specified both in the
revised request and within this proposed authorization may result in
the modification, suspension, or revocation of the IHA.
(2) If project activities cause unauthorized take (i.e., greater
than 162 takes of the Southcentral Alaska stock of northern sea otters,
a form of take other than Level A harassment or Level B harassment, or
take of one or more sea otters through methods not described in the
IHA), TMC must take the following actions:
(i) Cease its activities immediately (or reduce activities to the
minimum level necessary to maintain safety);
(ii) Report the details of the incident to the FWS within 48 hours;
and
(iii) Suspend further activities until the FWS has reviewed the
circumstances and determined whether additional mitigation measures are
necessary to avoid further unauthorized taking.
(3) All operations managers, vehicle operators, and machine
operators must receive a copy of this IHA and maintain access to it for
reference at all times during project work. These personnel must
understand, be fully aware of, and be capable of implementing the
conditions of the IHA at all times during project work.
(4) This IHA will apply to activities associated with the specified
project as described in this document and in TMC's revised request.
Changes to the specified project without prior authorization may
invalidate the IHA.
(5) TMC's revised request is approved and fully incorporated into
this IHA unless exceptions are specifically noted herein. The request
includes:
(i) TMC's original request for an IHA, dated March 1, 2024;
(ii) A revised application, dated March 18, 2024; and
(iii) Marine Mammal Mitigation and Monitoring Plan.
(6) Operators will allow the FWS personnel or the FWS's designated
representative to visit project worksites to monitor for impacts to sea
otters and subsistence uses of sea otters at any time throughout
project activities so long as it is safe to do so. ``Operators'' are
all personnel operating under TMC's authority, including all
contractors and subcontractors.
B. Avoidance and Minimization
(7) Construction activities must be conducted using equipment that
generates the lowest practicable levels of underwater sound within the
range of frequencies audible to sea otters.
(8) During all pile-installation activities, regardless of
predicted sound levels, a physical interaction shutdown zone of 10 m
(33 ft) must be enforced. If a sea otter enters the shutdown zone, in-
water activities must be delayed until either the animal has been
visually observed outside the shutdown zone, or 15 minutes have elapsed
since the last observation time without redetection of the animal.
(9) If the impact driver has been idled for more than 30 minutes,
an initial set of three strikes from the impact driver must be
delivered at reduced energy, followed by a 1-minute waiting period,
before full-powered proofing strikes.
(10) In-water activity must be conducted in daylight. If
environmental conditions prevent visual detection of sea otters within
the shutdown zone, in-water activities must be stopped until visibility
is regained.
C. Mitigation Measures for Vessel Operations
Vessel operators must take every precaution to avoid harassment of
sea otters when a vessel is operating near these animals. The applicant
must carry out the following measures:
(11) Vessels must remain at least 500 m (0.3 mi) from rafts of sea
otters unless safety is a factor. Vessels must reduce speed and
maintain a distance of 100 m (328 ft) from all sea otters unless safety
is a factor.
(12) Vessels must not be operated in such a way as to separate
members of a group of sea otters from other members of the group and
must avoid alongshore travel in shallow water (<20 m) whenever
practicable.
(13) When weather conditions require, such as when visibility
drops, vessels must adjust speed accordingly to avoid the likelihood of
injury to sea otters.
(14) Vessel operators must be provided written guidance for
avoiding collisions and minimizing disturbances to sea otters. Guidance
will include all measures identified in this section.
D. Monitoring
(15) Operators shall work with PSOs to apply mitigation measures
and shall recognize the authority of PSOs up to and including stopping
work, except where doing so poses a significant safety risk to
personnel.
(16) Duties of the PSOs include watching for and identifying sea
otters, recording observation details, documenting presence in any
applicable monitoring zone, identifying and documenting potential
harassment, and working with operators to implement all appropriate
mitigation measures.
(17) A sufficient number of PSOs will be available to meet the
following criteria: 100 percent monitoring of exclusion zones during
all daytime periods of underwater noise-generating work; a maximum of 4
consecutive hours on watch per PSO; a maximum of approximately 12 hours
on watch per day per PSO.
(18) All PSOs will complete a training course designed to
familiarize individuals with monitoring and data collection procedures.
A field crew leader with prior experience as a sea otter observer will
supervise the PSO team. Initially, new or inexperienced PSOs will be
paired with experienced PSOs so that the quality of marine mammal
observations and data recording is kept consistent. Resumes
[[Page 59765]]
for candidate PSOs will be made available for the FWS to review.
(19) Observers will be provided with reticule binoculars (7x50 or
better), big-eye binoculars or spotting scopes (30x), inclinometers,
and range finders. Field guides, instructional handbooks, maps, and a
contact list will also be made available.
(20) Observers will collect data using the following procedures:
(i) All data will be recorded onto a field form or database.
(ii) Global positioning system data, sea state, wind force, and
weather will be collected at the beginning and end of a monitoring
period, every hour in between, at the change of an observer, and upon
sightings of sea otters.
(iii) Observation records of sea otters will include date; time;
the observer's locations, heading, and speed (if moving); weather;
visibility; number of animals; group size and composition (adults/
juveniles); and the location of the animals (or distance and direction
from the observer).
(iv) Observation records will also include initial behaviors of the
sea otters, descriptions of project activities and underwater sound
levels being generated, the position of sea otters relative to
applicable monitoring and mitigation zones, any mitigation measures
applied, and any apparent reactions to the project activities before
and after mitigation.
(v) For all sea otters in or near a mitigation zone, observers will
record the distance from the sound source to the sea otter upon initial
observation, the duration of the encounter, and the distance at last
observation in order to monitor cumulative sound exposures.
(vi) Observers will note any instances of animals lingering close
to or traveling with vessels for prolonged periods of time.
(21) Monitoring of the shutdown zone must continue for 30 minutes
following completion of pile installation.
E. Measures To Reduce Impacts to Subsistence Users
(22) Prior to conducting the work, TMC will take the following
steps to reduce potential effects on subsistence harvest of sea otters:
(i) Avoid work in areas of known sea otter subsistence harvest;
(ii) Discuss the planned activities with subsistence stakeholders
including Southcentral Alaska villages and traditional councils;
(iii) Identify and work to resolve concerns of stakeholders
regarding the project's effects on subsistence hunting of sea otters;
and
(iv) If any concerns remain, develop a POC in consultation with the
FWS and subsistence stakeholders to address these concerns.
F. Reporting Requirements
(23) The applicant, TMC, must notify the FWS at least 48 hours
prior to commencement of activities.
(24) Monthly reports will be submitted to the FWS's Marine Mammal
Management office (MMM) for all months during which noise-generating
work takes place. The monthly report will contain and summarize the
following information: dates, times, weather, and sea conditions
(including the Beaufort Scale sea state and wind force conditions) when
sea otters were sighted; the number, location, distance from the sound
source, and behavior of the sea otters; the associated project
activities; and a description of the implementation and effectiveness
of mitigation measures with a discussion of any specific behaviors the
sea otters exhibited in response to mitigation.
(25) A final report will be submitted to the FWS's MMM within 90
days after completion of work or expiration of the IHA. The report will
include:
(i) A summary of monitoring efforts (hours of monitoring,
activities monitored, number of PSOs, and, if requested by the FWS, the
daily monitoring logs).
(ii) A description of all project activities, along with any
additional work yet to be done. Factors influencing visibility and
detectability of marine mammals (e.g., sea state, number of observers,
and fog and glare) will be discussed.
(iii) A description of the factors affecting the presence and
distribution of sea otters (e.g., weather, sea state, and project
activities). An estimate will be included of the number of sea otters
exposed to noise at received levels corresponding to Level A harassment
or Level B harassment (based on visual observation).
(iv) A description of changes in sea otter behavior resulting from
project activities and any specific behaviors of interest.
(v) A discussion of the mitigation measures implemented during
project activities and their observed effectiveness for minimizing
impacts to sea otters. Sea otter observation records will be provided
to the FWS in the form of electronic database or spreadsheet files.
(26) Injured, dead, or distressed sea otters that are not
associated with project activities (e.g., animals known to be from
outside the project area, previously wounded animals, or carcasses with
moderate to advanced decomposition or scavenger damage) must be
reported to the FWS within 24 hours of the discovery to either the
FWS's MMM Office (1-800-362-5148, business hours); or the Alaska
SeaLife Center in Seward (1-888-774-7325, 24 hours a day), or both.
Photographs, video, location information, or any other available
documentation must be provided to the FWS.
(27) All reports shall be submitted by email to
<a href="/cdn-cgi/l/email-protection#9cdacbabc3f1f1f1c3eef9ecf3eee8efdcfaebefb2fbf3ea"><span class="__cf_email__" data-cfemail="c78190f098aaaaaa98b5a2b7a8b5b3b487a1b0b4e9a0a8b1">[email protected]</span></a>.
(28) TMC must notify the FWS upon project completion or end of the
work season.
Request for Public Comments
If you wish to comment on this proposed authorization, the
associated draft environmental assessment, or related documents, you
may submit your comments by either of the methods described in
ADDRESSES. Please identify the document(s) to which your comments
pertain, make your comments as specific as possible, confine them to
issues pertinent to the proposed authorization, and explain the reason
for any changes you recommend. Where possible, your comments should
reference the specific section or paragraph that you are addressing.
The FWS will consider all comments that are received before the close
of the comment period (see DATES). The FWS does not anticipate
extending the public comment period beyond the 30 days required under
section 101(a)(5)(D)(iii) of the MMPA.
Comments, including names and street addresses of respondents, will
become part of the administrative record for this proposal. Before
including your address, telephone number, email address, or other
personal identifying information in your comment, be advised that your
entire comment, including your personal identifying information, may be
made publicly available at any time. While you can ask us in your
comments to withhold from public review your personal identifying
information, we cannot guarantee that we will be able to do so.
Peter Fasbender,
Assistant Regional Director for Fisheries and Ecological Services,
Alaska Region.
[FR Doc. 2024-16166 Filed 7-22-24; 8:45 am]
BILLING CODE 4333-15-P
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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.