www.gpo.gov]
[FR Doc No: 2023-12233]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
[Docket No. FWS-R7-ES-2023-0030; FXES111607MRG01-234-FF07CAMM00]
Marine Mammals; Incidental Take During Specified Activities;
Proposed Incidental Harassment Authorization for Southcentral Alaska
Stock of Northern Sea Otters in Whittier, Alaska
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of receipt of application; proposed incidental
harassment authorization; draft environmental assessment; request for
comments.
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SUMMARY: We, the U.S. Fish and Wildlife Service, 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 the Southcentral
Alaska stock of northern sea otters (Enhydra lutris kenyoni) for 1 year
from the date of issuance of the incidental harassment authorization.
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 44 northern sea otters
from the Southcentral stock. This proposed authorization, if finalized,
will be for up to 70 takes of 7 northern sea otters by Level A
harassment and 544 takes of 37 northern sea otters by Level B
harassment. No lethal take is requested, or expected, and no such take
will be authorized.
DATES: Comments on this proposed incidental harassment authorization
and
[[Page 37557]]
the accompanying draft environmental assessment must be received by
July 10, 2023.
ADDRESSES:
Document availability: You may view this proposed incidental
harassment authorization, the application package, supporting
information, draft environmental assessment, and the list of references
cited herein at https://www.regulations.gov under Docket No. FWS-R7-ES-
2023-0030 or these documents may be requested 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:
U.S. mail: Public Comments Processing, Attn: Docket No.
FWS-R7-ES-2023-0030, U.S. Fish and Wildlife Service, MS: PRB (JAO/3W),
5275 Leesburg Pike, Falls Church, VA 22041-3803.
Electronic submission: Federal eRulemaking Portal at:
https://www.regulations.gov. Follow the instructions for submitting
comments to Docket No. FWS-R7-ES-2023-0030.
We will post all comments at https://www.regulations.gov. 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: Sierra Franks, U.S. Fish and Wildlife
Service, MS 341, 1011 East Tudor Road, Anchorage, Alaska 99503, by
email at R7mmmregulatory@fws.gov or by telephone at 1-800-362-5148.
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 (``Service'' or ``we''). According
to the MMPA, the Service shall allow this incidental taking 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:
(a) permissible methods of taking;
(b) 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
(c) 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 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 September 16, 2022, Turnagain Marine Construction (hereafter
``TMC'' or ``the applicant'') submitted a request to the Service for
authorization to take by Level A 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 Service sent requests for additional
information on November 1, November 30, and December 14, 2022. We
received updated versions of the request on November 11, November 23,
December 1, and December 22, 2022. The Service determined the December
22, 2022, application to be adequate and complete. TMC expects take by
[[Page 37558]]
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) between April 2023 and April 2024. TMC will install
and remove 72 91-centimeter (cm) (36-inch (in)) diameter steel piles
and will permanently install the following types of piles: 36 91-cm
(36-in) diameter steel piles, 16 107-cm (42-in) diameter steel piles,
and 20 122-cm (48-in) diameter steel piles. 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 129 non-consecutive days for approximately
321 hours during the course of 1 year from date of issuance of the IHA.
If the IHA is issued after TMC's intended start date in April 2023, 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.
[GRAPHIC] [TIFF OMITTED] TN08JN23.001
Description of Marine Mammals in the Specified Geographic Region
Sea Otter Biology
There are three sea otter stocks in Alaska: Southeast Alaska stock,
Southcentral Alaska stock, and the Southwest Alaska stock. Only the
Southcentral Alaska stock is represented in the project area. Detailed
information about the biology of this stock can be found in the most
recent Southcentral Alaska draft stock assessment report (USFWS 2023),
which can be found at https://www.regulations.gov/document/FWS-R7-ES-2022-0155-0004 and was announced in the Federal Register at 88 FR 7992,
February 7, 2023.
Sea otters may be distributed anywhere within the specified project
area other than upland areas; however, they generally occur in shallow
water near the shoreline. They are most commonly observed within the
40-m (131-ft) depth contour (USFWS 2023), although they can be found in
areas with deeper water. Ocean depth is generally correlated with
distance to shore, and sea otters typically remain
[[Page 37559]]
within 1 to 2 kilometers (km) (0.62 to 1.24 miles (mi)) of shore
(Riedman and Estes 1990). They tend to be found closer to shore during
storms, but venture farther out during good weather and calm seas
(Lensink 1962; Kenyon 1969).
Sea otters are nonmigratory and generally do not disperse over long
distances (Garshelis and Garshelis 1984), usually remaining within a
few kilometers of their established feeding grounds (Kenyon 1981).
Breeding males stay for all or part of the year in a breeding territory
covering up to 1 km (0.62 mi) of coastline, while adult females
maintain home ranges of approximately 8 to 16 km (5 to 10 mi), which
may include one or more male territories. Juveniles move greater
distances between resting and foraging areas (Lensink 1962; Kenyon
1969; Riedman and Estes 1990; Tinker and Estes 1996). Although sea
otters generally remain local to an area, they are capable of long-
distance travel. Sea otters in Alaska have shown daily movement
distances greater than 3 km (1.9 mi) at speeds up to 5.5 km per hour
(hr) (km/hr; 3.4 mi/hr) (Garshelis and Garshelis 1984).
Southcentral Alaska Sea Otter Stock
The Southcentral Alaska sea otter stock occurs in the center of the
sea otter range in Alaska and extends from Cape Yakataga in the east to
Cook Inlet in the west, including Prince William Sound, the eastern
Kenai Peninsula coast, and Kachemak Bay (USFWS 2023). Between 2014 and
2019, aerial surveys were conducted in three regions of the
Southcentral Alaska sea otter stock: (1) Eastern Cook Inlet, (2) Outer
Kenai Peninsula, and (3) Prince William Sound by aerial transects flown
at 91 m (298.56 ft) of altitude. The combined estimates of the three
regions resulted in approximately 21,617 (SE = 2,190) sea otters and an
average density of 1.96 sea otters per square kilometer (km\2\) for the
Southcentral Alaska stock (Esslinger et al. 2021). We applied the
average density of sea otters in Prince William Sound, 2.03 sea otters/
km\2\ (Esslinger et al. 2021).
Potential Impacts of the Specified Activities on Marine Mammals
Effects of Noise on Sea Otters
We characterized ``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'' or ``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.
Sea Otter Hearing
Pile driving and marine construction activities 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 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 0.125-1 kHz were between
116-101 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
Noise exposure criteria for identifying underwater noise levels
capable of causing Level A harassment 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 sensitivity of hearing
(i.e., a permanent threshold shift (PTS) (NMFS 2018)). 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 (SELCUM) during a 24-hour
period. They also include weighting adjustments for the sensitivity of
different species to varying frequencies. 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). Southall and colleagues (2019) predict
PTS for sea otters, which are included in the ``other marine
carnivores'' category, will occur at 232 dB peak or 203 dB
SELCUM for impulsive underwater sound and 219 dB
SELCUM 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
SELCUM. 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 (min)) and 178 dB SEL (148 dB, 15 min). 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 SELCUM for impulsive sounds and 199 dB
SELCUM 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
[[Page 37560]]
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 to 160 dB, and most marine mammals
showed some, albeit variable, responses to sound between 140 to 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 of 140, 160, and 180 dB, respectively.
We have evaluated these thresholds and determined that the Level B
threshold of 120 dB for nonimpulsive noise is not applicable to sea
otters. The 120-dB threshold is 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 Service has set 160 dB of received underwater sound as a
threshold for Level B harassment by disturbance for sea otters for this
proposed IHA. Exposure to unmitigated 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 Service as Level
B harassment. Thresholds for Level A harassment (which entails the
potential for injury) 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. Southall et al. (2007)
suggested thresholds for PTS and TTS for sea lions exposed to nonpulsed
airborne noise of 172.5 and 159 dB re (20 [micro]Pa)\2\-s SEL.
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 Includes Sea Otters
[Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure level (SELCUM dB re (20 micropascal
([micro]Pa) in air and SELCUM dB re 1 [micro]Pa in water) for impulsive and nonimpulsive sounds and unweighted peak sound pressure level (SPL) in air
(dB re 20 [micro]Pa) and water (dB 1 [micro]Pa) (impulsive sounds only).]
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TTS PTS
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Nonimpulsive Impulsive Nonimpulsive Impulsive
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SELCUM SELCUM Peak SPL SELCUM SELCUM Peak SPL
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Air..................................................... 157 146 170 177 161 176
Water................................................... 199 188 226 219 203 232
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Evidence From Sea Otter Studies
Sea otters may be more resistant to the effects of sound
disturbance and human activities than other marine mammals. For
example, observers have noted no changes from southern sea otters in
regard to their presence, density, or behavior in response to
underwater sounds from industrial noise recordings at 110 dB and a
frequency range of 50 Hz to 20 kHz and airguns, even at the closest
distance of 0.5 nautical miles (<1 km or 0.6 mi) (Riedman 1983).
Southern sea otters did not respond noticeably to noise from a single
1,638 cubic centimeters (cm\3\) (100 cubic inches [in\3\]) airgun, and
no sea otter disturbance reactions were evident when a 67,006 cm\3\
(4,089 in\3\) airgun array was as close as 0.9 km (0.6 mi) to sea
otters (Riedman 1983, 1984). However, southern sea otters displayed
slight reactions to airborne engine noise (Riedman 1983). Northern sea
otters were observed to exhibit a limited response to a variety of
airborne and underwater sounds, including a warble tone, sea otter pup
calls, calls from killer whales (Orcinus orca) (which are predators to
sea otters), air horns, and an underwater noise harassment system
designed to drive marine mammals away from crude oil spills (Davis et
al. 1988). These sounds elicited reactions from northern sea otters,
including startle responses and movement away from noise sources.
However, these reactions were observed only when northern sea otters
were within 100 to 200 m (328 to 656 ft) of noise sources. Further,
northern sea otters appeared to become habituated to the noises within
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2 hours or, at most, 3-4 days (Davis et al. 1988).
Noise exposure may be influenced by the amount of time sea otters
spend at the water's surface. Noise at the water's surface can be
attenuated by turbulence from wind and waves more quickly compared to
deeper water, reducing potential noise exposure (Greene and Richardson
1988, Richardson et al. 1995). Additionally, turbulence at the water's
surface limits the transference of sound from water to air. A sea otter
with its head above water will be exposed to only a small fraction of
the sound energy traveling through the water beneath it. The average
amount of time that sea otters spend above the water each day while
resting and grooming varies between males and females and across
seasons (Esslinger et al. 2014, Zellmer et al. 2021). For example,
female sea otters foraged for an average of 8.78 hours per day compared
to male sea otters, which foraged for an average of 7.85 hours per day
during the summer months (Esslinger et al. 2014). Male and female sea
otters spend an average of 63 to 67 percent of their day at the surface
resting and grooming during the summer months (Esslinger et al. 2014).
Few studies have evaluated foraging times during the winter months.
Garshelis et al. (1986) found that foraging times increased from 5.1
hours per day to 16.6 hours per day in the winter; however, Gelatt et
al. (2002) did not find a significant difference in seasonal foraging
times. It is likely that seasonal variation is determined by seasonal
differences in energetic demand and the quality and availability of
prey sources (Esslinger et al. 2014). These findings suggest that the
large portion of the day sea otters spend at the surface may help limit
sea otters' exposure during noise-generating operations.
Sea otter sensitivity to industrial activities may be influenced by
the overall level of human activity within the sea otter population's
range. In locations that lack frequent human activity, sea otters
appear to have a lower threshold for disturbance. Sea otters in Alaska
exhibited escape behaviors in response to the presence and approach of
vessels (Udevitz et al. 1995). Behaviors included diving or actively
swimming away from a vessel, entering the water from haulouts, and
disbanding groups with sea otters swimming in multiple different
directions (Udevitz et al. 1995). Sea otters in Alaska were also
observed to avoid areas with heavy boat traffic in the summer and
return to these areas during seasons with less vessel traffic
(Garshelis and Garshelis 1984). In Cook Inlet, sea otters drifting on a
tide trajectory that would have taken them within 500 m (0.3 mi) of an
active offshore drilling rig were observed to swim in order to avoid a
close approach of the drilling rig despite near-ambient noise levels
(BlueCrest 2013).
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 (i.e., 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, are less likely to be displaced.
Consequences of Disturbance
The reactions of wildlife to disturbance can range from short-term
behavioral changes to long-term impacts that affect survival and
reproduction. When disturbed by noise, animals may respond behaviorally
(e.g., escape response) or physiologically (e.g., increased heart rate,
hormonal response) (Harms et al. 1997; Tempel and Guti[eacute]rrez
2003). Theoretically, the energy expense and associated physiological
effects from repeated disturbance could ultimately lead to reduced
survival and reproduction (Gill and Sutherland 2000; Frid and Dill
2002). For example, South American sea lions (Otaria byronia) visited
by tourists exhibited an increase in the state of alertness and a
decrease in maternal attendance and resting time on land, thereby
potentially reducing population size (Pavez et al. 2015). In another
example, killer whales that lost feeding opportunities due to boat
traffic faced a substantial (18 percent) estimated decrease in energy
intake (Williams et al. 2006). In severe cases, such disturbance
effects could have population-level consequences. For example,
increased disturbance by tourism vessels has been associated with a
decline in abundance of bottlenose dolphins (Tursiops spp.) (Bejder et
al. 2006; Lusseau et al. 2006). However, these examples evaluated
sources of disturbance that were longer term and more consistent than
the temporary and intermittent nature of the specified project
activities.
These examples illustrate direct effects on survival and
reproductive success, but disturbances can also have indirect effects.
Response to noise disturbance is considered a nonlethal stimulus that
is similar to an antipredator response (Frid and Dill 2002). Sea otters
are susceptible to predation, particularly from killer whales and
eagles, and have a well-developed antipredator response to perceived
threats. For example, the presence of a harbor seal (Phoca vitulina)
did not appear to disturb southern sea otters, but they demonstrated a
fear response in the presence of a California sea lion by actively
looking above and beneath the water (Limbaugh 1961).
Although an increase in vigilance or a flight response is
nonlethal, a tradeoff occurs between risk avoidance and energy
conservation. An animal's reactions to noise disturbance may cause
stress and direct an animal's energy away from fitness-enhancing
activities such as feeding and mating (Frid and Dill 2002; Goudie and
Jones 2004). For example, southern sea otters in areas with heavy
recreational boat traffic demonstrated changes in behavioral time
budgeting, showing decreased time resting and changes in haulout
patterns and distribution (Benham 2006; Maldini et al. 2012). Chronic
stress can also lead to weakened reflexes, lowered learning responses
(Welch and Welch 1970; van Polanen Petel et al. 2006), compromised
immune function, decreased body weight, and abnormal thyroid function
(Selye 1979).
Changes in behavior resulting from anthropogenic disturbance can
include increased agonistic interactions between individuals or
temporary or permanent abandonment of an area (Barton et al. 1998).
Additionally, the extent of previous exposure to humans (Holcomb et al.
2009), the type of disturbance (Andersen et al. 2012), and the age or
sex of the individuals (Shaughnessy et al. 2008; Holcomb et al. 2009)
may influence the type and extent of response in individual sea otters.
Vessel Activities
Vessel collisions with marine mammals can result in death or
serious injury. Wounds resulting from vessel
[[Page 37562]]
strike may include massive trauma, hemorrhaging, broken bones, or
propeller lacerations (Knowlton and Kraus 2001). An animal may be
harmed by a vessel when the vessel runs over the animal at the surface,
the animal hits the bottom of a vessel while the animal is surfacing,
or the animal is cut by a vessel's propeller.
Vessel strike has been documented as a cause of death across all
three stocks of northern sea otters in Alaska. Since 2002, the Service
has conducted 1,433 sea otter necropsies to determine cause of death,
disease incidence, and the general health status of sea otters in
Alaska. Vessel strike or blunt trauma was identified as a definitive or
presumptive cause of death in 65 cases (4 percent) (USFWS 2020). In
most of these cases, trauma was determined to be the ultimate cause of
death; however, there was a contributing factor, such as disease or
biotoxin exposure, which incapacitated the sea otter and made it more
vulnerable to vessel strike (USFWS 2023).
Vessel speed influences the likelihood of vessel strikes involving
sea otters. The probability of death or serious injury to a marine
mammal increases as vessel speed increases (Laist et al. 2001,
Vanderlaan and Taggart 2007). Sea otters spend a considerable portion
of their time at the water's surface (Esslinger et al. 2014). They are
typically visually aware of approaching vessels and can move away if a
vessel is not traveling too quickly. Mitigation measures to be applied
to vessel operations to prevent collisions or interactions are included
below in the proposed authorization portion of this document under
Avoidance and Minimization.
Sea otters exhibit behavioral flexibility in response to vessels,
and their responses may be influenced by the intensity and duration of
the vessel's activity. As noted above, sea otter populations in Alaska
were observed to avoid areas with heavy vessel traffic but return to
those same areas during seasons with less vessel traffic (Garshelis and
Garshelis 1984). Sea otters have also shown signs of disturbance or
escape behaviors in response to the presence and approach of survey
vessels including sea otters diving and/or actively swimming away from
a vessel, sea otters on haulouts entering the water, and groups of sea
otters disbanding and swimming in multiple different directions
(Udevitz et al. 1995).
Additionally, sea otter responses to vessels may be influenced by
the sea otter's previous experience with vessels. Groups of southern
sea otters in two locations in California showed markedly different
responses to kayakers approaching to within specific distances,
suggesting a different level of tolerance between the groups (Gunvalson
2011). Benham (2006) found evidence that the sea otters exposed to high
levels of recreational activity may have become more tolerant than
individuals in less-disturbed areas. Sea otters off the California
coast showed only mild interest in vessels passing within hundreds of
meters and appeared to have habituated to vessel traffic (Riedman 1983,
Curland 1997). These findings indicate that sea otters may adjust their
responses to vessel activities depending on the level of activity.
Vessel activity during the project includes the transit of three barges
for materials and construction, all of which will remain onsite, 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.
Effects on Sea Otter Habitat and Prey
Physical and biological features of habitat essential to the
conservation of sea otters include the benthic invertebrates that sea
otters eat and the shallow rocky areas and kelp beds that provide cover
from predators. Sea otter habitat in the project area includes coastal
areas within the 40-m (131-ft) depth contour where high densities of
sea otters have been detected.
Industrial activities, such as pile driving, may generate in-water
noise at levels that can temporarily displace sea otters from important
habitat and impact sea otter prey species. The primary prey species for
sea otters are sea urchins (Strongylocentrotus spp. and Mesocentrotus
spp.), abalone (Haliotis spp.), clams (e.g., Clinocardium nuttallii,
Leukoma staminea, and Saxidomus gigantea), mussels (Mytilus spp.),
crabs (e.g., Metacarcinus magister, Pugettia spp., Telemessus
cheiragonus, and Cancer spp.), and squid (Loligo spp.) (Tinker and
Estes 1996, LaRoche et al. 2021). When preferential prey are scarce,
sea otters will also eat kelp, slow-moving benthic fishes, sea
cucumbers (e.g., Apostichopus californicus), egg cases of rays, turban
snails (Tegula spp.), octopuses (e.g., Octopus spp.), barnacles
(Balanus spp.), sea stars (e.g., Pycnopodia helianthoides), scallops
(e.g., Patinopecten caurinus), rock oysters (Saccostrea spp.), worms
(e.g., Eudistylia spp.), and chitons (e.g., Mopalia spp.) (Riedman and
Estes 1990, Davis and Bodkin 2021).
Several studies have addressed the effects of noise on
invertebrates (Tidau and Briffa 2016, Carroll et al. 2017). Behavioral
changes, such as an increase in lobster (Homarus americanus) feeding
levels (Payne et al. 2007), an increase in avoidance behavior by wild-
caught captive reef squid (Sepioteuthis australis) (Fewtrell and
McCauley 2012), and deeper digging by razor clams (Sinonovacula
constricta) (Peng et al. 2016) have been observed following
experimental exposures to sound. Physical changes have also been
observed in response to increased sound levels, including changes in
serum biochemistry and hepatopancreatic cells in lobsters (Payne et al.
2007) and long-term damage to the statocysts required for hearing in
several cephalopod species (Andr[eacute] et al. 2011, Sol[eacute] et
al. 2013). De Soto et al. (2013) found impaired embryonic development
in scallop (Pecten novaezelandiae) larvae when exposed to 160 dB.
Christian et al. (2003) noted a reduction in the speed of egg
development of bottom-dwelling crabs following exposure to noise;
however, the sound level (221 dB at 2 m or 6.6 ft) was far higher than
the planned project activities will produce. Industrial noise can also
impact larval settlement by masking the natural acoustic settlement
cues for crustaceans and fish (Pine et al. 2012, Simpson et al. 2016,
Tidau and Briffa 2016).
While these studies provide evidence of deleterious effects to
invertebrates as a result of increased sound levels, Carroll et al.
(2017) caution that there is a wide disparity between results obtained
in field and laboratory settings. In experimental settings, changes
were observed only when animals were housed in enclosed tanks, and many
were exposed to prolonged bouts of continuous, pure tones. We would not
expect similar results in open marine conditions. It is unlikely that
noises generated by project activities will have any lasting effect on
sea otter prey given the short-term duration of sounds produced by each
component of the planned work.
Noise-generating activities that interact with the seabed can
produce vibrations, resulting in the disturbance of sediment and
increased turbidity in the water. Although turbidity is likely to have
little impact on sea otters and prey species (Todd et al. 2015), there
may be some impacts from vibrations and increased sedimentation. For
example,
[[Page 37563]]
mussels (Mytilus edulis) exhibited changes in valve gape and oxygen
demand, and hermit crabs (Pagurus bernhardus) exhibited limited
behavioral changes in response to vibrations caused by pile driving
(Roberts et al. 2016). Increased sedimentation is likely to reduce sea
otter visibility, which may result in reduced foraging efficiency and a
potential shift to less-preferred prey species. These outcomes may
cause sea otters to spend more energy on foraging or processing the
prey items; however, the impacts of a change in energy expenditure are
not likely seen at the population level (Newsome et al. 2015).
Additionally, the benthic invertebrates may be impacted by increased
sedimentation, resulting in higher abundances of opportunistic species
that recover quickly from industrial activities that increase
sedimentation (Kotta et al. 2009). Although sea otter foraging could be
impacted by industrial activities that cause vibrations and increased
sedimentation, it is more likely that sea otters would be temporarily
displaced from the project area due to impacts from noise rather than
vibrations and sedimentation.
Potential Impacts of the Specified Activities on Subsistence Uses
The planned specified activities will occur near marine subsistence
harvest areas used by Alaska Natives from Whittier and the surrounding
areas. The majority of sea otter harvest in this area occurs more than
3.2 km (2 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 Service
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 three potential types of take of
sea otters. The Service does not anticipate and is not authorizing
lethal take as a part of this proposed IHA; however, the definitions of
these take types are provided for context and background:
Lethal Take--Human activity may result in biologically significant
impacts to sea otters. In the most serious interactions, human actions
can result in 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 behavioral patterns, including, but not
limited to, migration, breathing, nursing, feeding, or sheltering.
Changes in behavior that disrupt biologically significant behaviors or
activities for the affected animal are indicative of take by Level B
harassment under the MMPA.
The Service has identified the following sea otter behaviors as
indicative of possible Level B harassment:
Swimming away at a fast pace on belly (i.e., porpoising);
Repeatedly raising the head vertically above the water to
get a better view (spyhopping) while apparently agitated or while
swimming away;
In the case of a pup, repeatedly spyhopping while hiding
behind and holding onto its mother's head;
Abandoning prey or feeding area;
Ceasing to nurse and/or rest (applies to dependent pups);
Ceasing to rest (applies to independent animals);
Ceasing to use movement corridors;
Ceasing mating behaviors;
Shifting/jostling/agitation in a raft so that the raft
disperses;
Sudden diving of an entire raft; or
Flushing animals off a haulout.
This list is not meant to encompass all possible behaviors; other
behavioral responses may equate to take by 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 Service does not
view such minor changes in behavior as indicative of a take by 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 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 NMFS Technical Guidance and User Spreadsheet
(NMFS 2018, 2020) to determine the distance at which sound levels would
attenuate to Level A harassment thresholds, and empirical data from the
proxy projects were used to determine the distance at which sound
levels would attenuate to Level B harassment thresholds (table 1). 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 sound pressure levels produced by DTH drilling were provided
by NMFS in
[[Page 37564]]
2022 via correspondence with Solstice Alaska Consulting, who created
the application for this IHA on behalf of TMC. We then used 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 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
[micro]Pa. However, due to the differences in how PTS and TTS
thresholds are calculated, as well as limited data of underwater sound
pressure levels from DTH drilling, the resultant Level A isopleths 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)
Pile size (temporary)- 91-cm (36-in) 91-cm (36-in) 107-cm (42-in) 122-cm (48-in)
installation (temporary)- removal (permanent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total number of piles.............. 72.................... 72.................... 36................... 16................... 20.
--------------------------------------------------------------------------------------------------------------------
Sound level........................ 166 dB re 1[micro]Pa at 10 m (RMS)
168.2 dB re 1[micro]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...... 15 minutes/pile.
Maximum number of piles per day.... 4..................... 4..................... 4.................... 4.................... 2.
Maximum number of days of activity. 18.................... 18.................... 9.................... 4.................... 10.
--------------------------------------------------------------------------------------------------------------------
Sea otter density.................. 2.03 sea otters/km\2\
--------------------------------------------------------------------------------------------------------------------
Distance to below Level A 0.5 meters............ 0.5 meters............ 0.6 meters........... 0.9 meters........... 0.6 meters.
harassment threshold.
Level A area (km\2\)............... 0.000001.............. 0.000001.............. 0.000001............. 0.000003............. 0.000001.
Potential sea otters affected by 0.000002.............. 0.000002.............. 0.000002............. 0.00001.............. 0.000002.
Level A sound per day.
Potential sea otters affected by 0..................... 0..................... 0.................... 0.................... 0.
Level A sound per day (rounded).
Total potential Level A harassment 0..................... 0..................... 0.................... 0.................... 0.
events.
Distance to below Level B 25 meters............. 25 meters............. 25 meters............ 35 meters............ 35 meters.
harassment threshold.
Level B area (km\2\)............... 0.0020................ 0.0020................ 0.0020............... 0.0038............... 0.0038.
Potential sea otters affected by 0.0041................ 0.0041................ 0.0041............... 0.0077............... 0.0077.
Level B sound per day.
Potential sea otters affected by 0..................... 0..................... 0.................... 0.................... 0.
Level B sound per day (rounded).
Total potential Level B harassment 0..................... 0..................... 0.................... 0.................... 0.
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)
Pile size (permanent) 107-cm (42-in) 122-cm (48-in)
----------------------------------------------------------------------------------------------------------------
Total number of piles................ 36..................... 16..................... 20.
Sound level.......................... 184 dB (SEL)/192 dB 186.7 dB (SEL)/198.6 dB 186.7 dB (SEL)/198.6 dB
(RMS)/211 dB (peak) re (RMS) re 1[micro]Pa at (RMS)/212 dB (peak) re
1[micro]Pa at 10 m. 10 m. 1[micro]Pa at 10 m.
-------------------------------------------------
Source............................... NAVFAC 2015............ Austin et al. 2016
-------------------------------------------------
Timing per pile...................... 45 minutes/pile; 1,800 60 minutes/pile; 2,400 60 minutes/pile; 2,400
strikes/pile. strikes/pile. strikes/pile.
Maximum number piles per day......... 4...................... 3...................... 2.
Maximum number of days of activity... 9...................... 5.3.................... 10.
--------------------------------------------------------------------------
Sea otter density.................... 2.03 sea otters/km\2\
--------------------------------------------------------------------------
Distance to below Level A harassment 169.2 meters........... 256.0 meters........... 195.4 meters.
threshold.
Level A area (km\2\)................. 0.0718................. 0.1786................. 0.1199.
[[Page 37565]]
Potential sea otters affected by 0.1458................. 0.3626................. 0.2434.
Level A sound per day.
Potential sea otters affected by 1...................... 1...................... 1.
Level A sound per day (rounded).
Total potential Level A harassment 9...................... 6...................... 10.
events.
Distance to below Level B harassment 1,359 meters........... 3,744 meters........... 3,744 meters.
threshold.
Level B area (km\2\)................. 1.9161................. 7.3224................. 7.8846.
Potential sea otters affected by 3.8897................. 14.8645................ 16.0057.
Level B sound per day.
Potential sea otters affected by 4...................... 15..................... 16.
Level B sound per day (rounded).
Total potential Level B harassment 36..................... 80..................... 160.
events.
----------------------------------------------------------------------------------------------------------------
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)
Pile size (temporary) (permanent) 107-cm (42-in) 122-cm (48-in)
----------------------------------------------------------------------------------------------------------------
Total number of piles........... 36 (installation 36................ 16................ 20.
only).
------------------------------------------------------------
Sound level..................... 164 dB (SEL)/167 dB (RMS) re 1[micro]Pa at 10 m 171 dB (SEL)/167
(RMS) dB re
1[micro]Pa at 10
m.
------------------------------------------------------------
Source.......................... Reyff and Heyvaert 2019; Reyff 2020; Denes et al. 2019; SolsticeAK 2022;
Heyvaert and Reyff 2021 Heyvaert and
Reyff 2021.
------------------------------------------------------------
Timing per pile................. 60 minutes/pile... 150 minutes/pile.. 150 minutes/pile.. 150 minutes/pile.
Maximum number piles per day.... 4................. 2................. 2................. 2.
Maximum number of days of 9................. 18................ 8................. 10.
activity.
-------------------------------------------------------------------------------
Sea otter density............... 2.03 sea otters/km\2\
-------------------------------------------------------------------------------
Distance to below Level A 57.9 meters....... 67.1 meters....... 67.1 meters....... 196.6 meters.
harassment threshold \a\.
Level A area (km\2\)............ 0.0105............ 0.0141............ 0.0141............ 0.1214.
Potential sea otters affected by 0.0213............ 0.0286............ 0.0286............ 0.2464.
Level A sound per day.
Potential sea otters affected by 1................. 1................. 1................. 1.
Level A sound per day (rounded).
Total potential Level A 9................. 18................ 8................. 10.
harassment events.
Distance to below Level B 29 meters......... 29 meters......... 29 meters......... 29 meters.
harassment threshold \a\.
Level B area (km\2\)............ 0.0026............ 0.0026............ 0.0026............ 0.0026.
Potential sea otters affected by 0.0053............ 0.0053............ 0.0053............ 0.0053.
Level B sound per day.
Potential sea otters affected by 0................. 0................. 0................. 0.
Level B sound per day (rounded).
Total potential Level B 0................. 0................. 0................. 0.
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[micro]Pa at 1 m. 1[micro]Pa at 1
m.
---------------------------------------
Source.......................... Richardson et al. 1995; Kipple and
Gabriele 2007
---------------------------------------
[[Page 37566]]
Number of days of vessel use.... 129............... 129.
---------------------------------------
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).
Total potential Level B 129............... 129.
harassment events.
------------------------------------------------------------------------
Sound levels for all sources are unweighted and given in dB re
1[micro]Pa. Nonimpulsive sounds are in the form of mean maximum root
mean square (RMS) sound pressure level (SPL) as it is more conservative
than cumulative sound exposure level (SEL) 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[micro]Pa due to pile driving, we multiplied the
area ensonified to >160 dB re 1[micro]Pa by the density of animals
(2.03 sea otters/km\2\) derived from surveys conducted off Prince
William Sound (Esslinger 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 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 36-in
permanent and 42-in piles, as well as the Level B zone generated by
impact pile driving the 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 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. 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 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 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 260 m (33 to 853 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 Service proposes to authorize, small numbers of take
by Level A harassment during impact pile driving and DTH drilling.
Critical Assumptions
We estimate that 544 takes of 37 sea otters by Level B harassment
and 70 takes of 7 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 significant biological consequences.
We used the sea otter density for the Whittier area from surveys
and analyses conducted by Esslinger (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
[[Page 37567]]
differing slightly from those estimated here.
We assumed that all piles will be installed and removed while
submerged in water. Some of the 36-in permanent piles supporting the
approach trestle, and the associated temporary 36-in piles used for the
templates to install the permanent piles, will be located in the
intertidal zone. Work performed at lower tidal heights would likely
result in decreased transmission of sounds to the water column.
However, as the timing of pile installation and removal was not known
in advance, we accounted for the possibility that all work may occur at
a tidal height that allows for full sound transmission.
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-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 and Level B Harassment of Sea Otters
----------------------------------------------------------------------------------------------------------------
Sea otters Total takes Sea otters Total takes
Number of exposed per of sea otters exposed per of sea otters
Source days of day to Level by Level A day to Level by Level B
activity A harassment harassment B harassment harassment
----------------------------------------------------------------------------------------------------------------
Vibratory drilling:
36-inch piles (temporary)-- 18 0 0 0 0
installation...............
36-inch piles (temporary)-- 18 0 0 0 0
removal....................
36-inch piles (permanent)... 9 0 0 0 0
42-inch piles............... 4 0 0 0 0
48-inch piles............... 10 0 0 0 0
Impact drilling:
36-inch piles (permanent)... 9 1 9 4 36
42-inch piles............... 6 1 6 15 90
48-inch piles............... 10 1 10 16 160
Down-the-hole drilling:
36-inch piles (temporary)-- 9 1 9 0 0
installation...............
36-inch piles (permanent)... 18 1 18 0 0
42-inch piles............... 8 1 8 0 0
48-inch piles............... 10 1 10 0 0
Skiff use:
Monitoring skiff............ 129 0 0 1 129
Worker transit skiff........ 129 0 0 1 129
-------------------------------------------------------------------------------
Totals.................. 387 7 70 37 544
----------------------------------------------------------------------------------------------------------------
Over the course of the project, we estimate 544 instances of take
by Level B harassment of 37 northern sea otters from the Southcentral
Alaska stock due to behavioral responses of 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 PSOs will be
able to reliably detect and prevent take by Level A harassment of sea
otters up to 20 m away; conversely, we anticipate that at distances
greater than 20 m, sea otters will at times avoid detection. Throughout
the project, we estimate 70 instances of take by Level A harassment of
7 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
[[Page 37568]]
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 takes 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 256 m (190 to 840
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 Service 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 TMC's specified activities in the specified geographic
region will take no more than 544 takes of 37 sea otters by Level B
harassment and 70 takes of 7 sea otters by Level A harassment during
the 1-year period of this proposed IHA (see Sum of Take from All
Sources). Take of 44 animals is 0.2 percent of the best available
estimate of the current Southcentral Alaska stock size of 21,617
animals (Esslinger et al. 2021) ((44 / 21,617) x 100 [ap] 0.2) and
represents a ``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. Each sea otter is
estimated to be exposed to construction noise for between 4 and 129
days per year, resulting in repeated exposures. However, injuries
(i.e., Level A harassment or PTS) due to chronic sound exposure is
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 0.18 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
614 incidental takes of 44 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.
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 effect 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 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:
Using the smallest diameter piles practicable while
minimizing the overall number of piles;
Using a project design that does not include dredging or
blasting;
Using pile caps made of high-density polyethylene or
ultra-high-molecular-weight polyethylene softening materials during
impact pile driving;
Minimizing the use of the impact hammer to the extent
possible by using
[[Page 37569]]
a vibratory hammer to advance piles as deeply as possible;
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;
Not reducing sound source levels due to the planned use of
pile caps and a bubble curtain to calculate the most conservative
harassment and shutdown zones;
Development of a marine mammal monitoring and mitigation
plan;
Establishment of shutdown and monitoring zones;
Visual mitigation monitoring by designated protected
species observers (PSO);
Site clearance before startup;
Soft-start procedures; and
Shutdown procedures.
The Service has not identified any additional (i.e., not already
incorporated into TMC's request) mitigation or monitoring measures that
are practicable and would further reduce potential impacts to sea
otters and their habitat.
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 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 Service 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 an approved plan for monitoring
and reporting the effects of pile driving and marine construction
activities on sea otters prior to issuance of an 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 (NEPA)
We have prepared a draft environmental assessment in accordance
with the 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 544 takes of 37 sea otters and by Level A
harassment of up to 70 takes of 7 sea otters from the Southcentral
Alaska stock 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 (ESA)
Under the 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 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 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 Natives. 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
Service 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
corporations, will not be impacted by this project. Regardless, we will
be reaching out to them 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.
Proposed Authorization
We propose to authorize the nonlethal, incidental take by Level A
and Level B harassment of 614 takes of 44 sea otters from the
Southcentral Alaska stock. Authorized take may be caused by pile
driving and marine construction activities conducted by Turnagain
Marine Construction (TMC) in Whittier, Alaska, over the course of a
year from the date of issuance of the IHA. We do not anticipate or
authorize any lethal take to sea otters resulting from these
activities.
[[Page 37570]]
A. General Conditions for the Incidental Harassment Authorization (IHA)
(1) Activities must be conducted in the manner described in the
December 22, 2022, 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 614 takes of 44 of the Southcentral Alaska stock of northern sea
otters, a form of take other than Level A 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 Service within 48
hours; and
(iii) suspend further activities until the Service 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 September 16, 2022;
(ii) Revised applications, dated November 11, November 23, December
1, and December 22, 2022;
(iii) Marine Mammal Mitigation and Monitoring Plan;
(iv) Google Earth package;
(v) Bubble curtain schematics; and
(vi) Pile coordinates.
(6) Operators will allow Service personnel or the Service'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 20 m
(66 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.
(11) All in-water work along the shoreline must be conducted during
low tide when the site is dewatered to the maximum extent practicable.
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:
(12) 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.
(13) 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.
(14) When weather conditions require, such as when visibility
drops, vessels must adjust speed accordingly to avoid the likelihood of
injury to sea otters.
(15) Vessel operators must be provided written guidance for
avoiding collisions and minimizing disturbances to sea otters. Guidance
will include measures identified in paragraphs (C)(12) through (15) of
this section.
D. Monitoring
(16) Operators shall work with protected species observers (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.
(17) 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.
(18) 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.
(19) 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 for
candidate PSOs will be made available for the Service to review.
(20) 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.
(21) 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).
[[Page 37571]]
(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.
(22) Monitoring of the shutdown zone must continue for 30 minutes
following completion of pile installation.
E. Measures To Reduce Impacts to Subsistence Users
(23) 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
Service and subsistence stakeholders to address these concerns.
F. Reporting Requirements
(24) TMC must notify the Service at least 48 hours prior to
commencement of activities.
(25) Monthly reports will be submitted to the Service'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.
(26) A final report will be submitted to the Service'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 Service,
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 greater than or equal to 160 dB
(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 Service in the form of electronic database or spreadsheet files.
(27) 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 Service within 24 hours of the discovery to either the
Service's MMM (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 Service.
(28) All reports shall be submitted by email to
fw7_mmm_reports@fws.gov.
(29) TMC must notify the Service 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 both documents, you may
submit your comments by either of the methods described in ADDRESSES.
Please identify if you are commenting on the proposed authorization,
draft environmental assessment, or both, 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 Service will consider all
comments that are received before the close of the comment period (see
DATES). The Service 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. 2023-12233 Filed 6-7-23; 8:45 am]
BILLING CODE 4333-15-P