[Federal Register Volume 89, Number 141 (Tuesday, July 23, 2024)]
[Notices]
[Pages 59752-59765]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-16166]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[Docket No. FWS-R7-ES-2024-0054; FXES111607MRG01-245-FF07CAMM00]


Marine Mammals; Incidental Take During Specified Activities; 
Proposed Incidental Harassment Authorization for Southcentral Alaska 
Stock of Northern Sea Otters in Whittier, AK; Draft Environmental 
Assessment

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of application and proposed authorization; 
notice of availability of draft environmental assessment; request for 
comments.

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SUMMARY: We, the U.S. Fish and Wildlife Service (FWS), in response to a 
request under the Marine Mammal Protection Act of 1972, as amended, 
from Turnagain Marine Construction, propose to authorize nonlethal, 
incidental take by harassment of small numbers of Southcentral Alaska 
stock northern sea otters (Enhydra lutris kenyoni) from July 19, 2024, 
to July 18, 2025. The applicant has requested this authorization for 
take by harassment that may result from activities associated with pile 
driving and marine construction activities on the western shore of 
Passage Canal in Whittier, Alaska. We estimate that this project may 
result in the nonlethal incidental take by harassment of up to 162 
northern sea otters from the Southcentral stock. This proposed 
authorization, if finalized, will be for up to 17 takes of northern sea 
otters by Level A harassment and 145 takes of northern sea otters by 
Level B harassment. Neither the applicant nor the FWS anticipated any 
lethal take, and the FWS does not propose to authorize any lethal take. 
We invite comments on the proposed incidental harassment authorization 
and the accompanying draft environmental assessment from the public, 
and local, State, Tribal and Federal agencies.

DATES: Comments must be received by August 22, 2024.

ADDRESSES: Document availability: You may view the application package, 
supporting information, the draft environmental assessment, and the 
list of references cited herein at https://www.regulations.gov under 
Docket No. FWS-R7-ES-2024-0054, or you may request these documents from 
the person listed under FOR FURTHER INFORMATION CONTACT.
    Comment submission: You may submit comments on the proposed 
authorization by one of the following methods:
     Internet: https://www.regulations.gov. Follow the 
instructions for submitting comments to Docket No. FWS-R7-ES-2024-0054.
     U.S. mail: Public Comments Processing, Attn: Docket No. 
FWS-R7-ES-2024-0054, U.S. Fish and Wildlife Service, MS: PRB (JAO/3W), 
5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We will post all comments at 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: Charles Hamilton, by email at 
[email protected], or by telephone at 1-800-362-5148 or 1-907-
786-3800. Individuals in the United States who are deaf, deafblind, 
hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or 
TeleBraille) to access telecommunications relay services. Individuals 
outside the United States should use the relay services offered within 
their country to make international calls to the point-of-contact in 
the United States.

SUPPLEMENTARY INFORMATION:

Background

    Section 101(a)(5)(D) of the Marine Mammal Protection Act of 1972 
(MMPA; 16 U.S.C. 1361 et seq.) authorizes the Secretary of the Interior 
(Secretary) to allow, upon request, the incidental, but not 
intentional, taking by harassment of small numbers of marine mammals in 
response to requests by U.S. citizens (as defined in title 50 of the 
Code of Federal Regulations (CFR) in part 18, at 50 CFR 18.27(c)) 
engaged in a specified activity (other than commercial fishing) in a 
specified geographic region during a period of not more than 1 year. 
The Secretary has delegated authority for implementation of the MMPA to 
the U.S. Fish and Wildlife Service (FWS, or we). According to the MMPA, 
the FWS shall allow this incidental taking by harassment if we make 
findings that the total of such taking for the 1-year period:
    1. Is of small numbers of marine mammals of a species or stock;
    2. Will have a negligible impact on such species or stocks; and
    3. Will not have an unmitigable adverse impact on the availability 
of these species or stocks for taking for subsistence use by Alaska 
Natives.
    If the requisite findings are made, we issue an authorization that 
sets forth the following, where applicable:
    1. Permissible methods of taking;
    2. Means of effecting the least practicable adverse impact on the 
species or stock and its habitat and the availability of the species or 
stock for subsistence uses; and
    3. Requirements for monitoring and reporting of such taking by 
harassment, including, in certain circumstances, requirements for the 
independent peer review of proposed monitoring plans or other research 
proposals.
    The term ``take'' means to harass, hunt, capture, or kill, or to 
attempt to harass, hunt, capture, or kill any marine mammal. 
``Harassment'' means any act of pursuit, torment, or annoyance which 
(i) has the potential to injure a marine mammal or marine mammal stock 
in the wild (the MMPA defines this as ``Level A harassment''), or (ii) 
has the potential to disturb a marine mammal or marine mammal stock in 
the wild by causing disruption of behavioral patterns, including, but 
not limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (the MMPA defines this as ``Level B harassment'').
    The terms ``negligible impact'' and ``unmitigable adverse impact'' 
are defined in 50 CFR 18.27 (i.e., regulations governing small takes of 
marine mammals incidental to specified activities) as follows: 
``Negligible impact'' is an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival. ``Unmitigable adverse impact'' 
means an impact resulting from the specified activity: (1) that is 
likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by (i) causing the 
marine mammals to abandon or avoid hunting areas, (ii) directly 
displacing subsistence users, or (iii) placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) that 
cannot be sufficiently mitigated by other measures to increase

[[Page 59753]]

the availability of marine mammals to allow subsistence needs to be 
met.
    The term ``small numbers'' is also defined in 50 CFR 18.27. 
However, we do not rely on that definition here as it conflates ``small 
numbers'' with ``negligible impacts.'' We recognize ``small numbers'' 
and ``negligible impacts'' as two separate and distinct considerations 
when reviewing requests for incidental harassment authorizations (IHA) 
under the MMPA (see Natural Res. Def. Council, Inc. v. Evans, 232 F. 
Supp. 2d 1003, 1025 (N.D. Cal. 2003)). Instead, for our small numbers 
determination, we estimate the likely number of takes of marine mammals 
and evaluate if that take is small relative to the size of the species 
or stock.
    The term ``least practicable adverse impact'' is not defined in the 
MMPA or its enacting regulations. For this IHA, we ensure the least 
practicable adverse impact by requiring mitigation measures that are 
effective in reducing the impact of project activities, but they are 
not so restrictive as to make project activities unduly burdensome or 
impossible to undertake and complete.
    If the requisite findings are made, we shall issue an IHA, which 
may set forth the following, where applicable: (i) permissible methods 
of taking; (ii) other means of effecting the least practicable impact 
on the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for subsistence 
uses by coastal-dwelling Alaska Natives (if applicable); and (iii) 
requirements for monitoring and reporting take by harassment.

Summary of Request

    On March 1, 2024, Turnagain Marine Construction (hereafter, TMC or 
the applicant) submitted a request to the FWS for an authorization to 
take by Level A harassment and Level B harassment a small number of 
northern sea otters (Enhydra lutris kenyoni) (hereafter, sea otters or 
otters unless another species is specified) from the Southcentral 
Alaska stock. The FWS sent a request for additional information on 
March 15, 2024. We received updated versions of the request on March 
18, 2024. The FWS determined the March 18, 2024, application to be 
adequate and complete. The applicant expects take by harassment may 
occur during the construction of their cruise ship berth and associated 
facilities on the western shore of Passage Canal in Whittier, Alaska.

Description of Specified Activities and Specified Geographic Region

    The specified activity (hereafter project) will include 
installation and removal of piles for the construction of a 152-by-21-
meter (m) (500-by-70-foot (ft)) floating cruise ship dock in Whittier, 
Alaska (figure 1). The applicant, TMC, plans to install and remove 15 
temporary steel piles, each of which will be 91 centimeters (cm) (36 
inches (in)) in diameter, and expects to install 7 permanent steel 
piles, each 91 cm (36 in) in diameter, and 8 permanent steel piles, 
each 122 cm (48 in) in diameter. Dock components that will be installed 
out of water include bull rail, fenders, mooring cleat, pre-cast 
concrete dock surface, and mast lights. Pile-driving activities will 
occur over 31 non-consecutive days for approximately 70 hours between 
July 19, 2024, and July 18, 2025. If the IHA is issued after TMC's 
intended start date, its schedule for conducting the specified 
activities may be adjusted accordingly. Pile installation will be done 
with a combination of impact, vibratory, and down-the-hole (DTH) 
drilling. Temporary piles will be removed with the vibratory hammer. 
Materials and equipment will be transported via barges and workers will 
be transported to and from the barge work platform via skiff.
    Additional project details may be reviewed in the application 
materials available as described under ADDRESSES or may also be 
requested as described under FOR FURTHER INFORMATION CONTACT.

[[Page 59754]]

[GRAPHIC] [TIFF OMITTED] TN23JY24.006


[[Page 59755]]



Description of Marine Mammals in the Specified Geographic Region

    The northern sea otter is the only species of marine mammal under 
FWS jurisdiction likely found within the specified geographic region. 
Information on range, stocks, and biology of sea otters can be found in 
the supplemental information (available as described above in 
ADDRESSES).

Potential Impacts of the Specified Activities on Marine Mammals

Effects of Noise on Sea Otters

    We characterize ``noise'' as sound released into the environment 
from human activities that exceeds ambient levels or interferes with 
normal sound production or reception by sea otters. The terms 
``acoustic disturbance'' and ``acoustic harassment'' are disturbances 
or harassment events resulting from noise exposure. Potential effects 
of noise exposure are likely to depend on the distance of the sea otter 
from the sound source, the level and intensity of sound the sea otter 
receives, background noise levels, noise frequency, noise duration, and 
whether the noise is pulsed or continuous. The actual noise level 
perceived by individual sea otters will also depend on whether the sea 
otter is above or below water and atmospheric and environmental 
conditions. Temporary disturbance of sea otters or localized 
displacement reactions are the most likely effects to occur from noise 
exposure. No lethal take is anticipated nor was authorization of lethal 
take requested by the applicant. Therefore, none will be authorized.

Sea Otter Hearing

    Pile driving and marine construction activities produce sound that 
will fall within the hearing range of sea otters. Controlled sound 
exposure trials on southern sea otters (Enhydra lutris nereis) indicate 
that sea otters can hear frequencies between 125 hertz (Hz) and 38 
kilohertz (kHz), with best sensitivity between 1.2 and 27 kHz (Ghoul 
and Reichmuth 2014). Aerial and underwater audiograms for a captive 
adult male southern sea otter in the presence of ambient noise suggest 
the sea otter's hearing was less sensitive to high-frequency (greater 
than 22 kHz) and low-frequency (less than 2 kHz) sound than that of 
terrestrial mustelids but was similar to that of a California sea lion 
(Zalophus californianus). However, the sea otter was still able to hear 
low-frequency sounds, and the detection thresholds for sounds between 
0.125 and 1 kHz were between 116 and 101 decibels (dB), respectively. 
Dominant frequencies of southern sea otter vocalizations are between 3 
and 8 kHz, with some energy extending above 60 kHz (McShane et al. 
1995; Ghoul and Reichmuth 2012).
    Exposure to high levels of sound may cause changes in behavior, 
masking of communications, temporary or permanent changes in hearing 
sensitivity, discomfort, and injury to marine mammals. Unlike other 
marine mammals, sea otters do not rely on sound to orient themselves, 
locate prey, or communicate under water; therefore, masking of 
communications by anthropogenic sound is less of a concern than for 
other marine mammals. However, sea otters, especially mothers and pups, 
do use sound for communication in air (McShane et al. 1995) and sea 
otters may monitor underwater sound to avoid predators (Davis et al. 
1987).

Exposure Thresholds

Underwater Sounds
    Noise exposure criteria for identifying underwater noise levels 
capable of causing Level A harassment (which entails the potential for 
injury) to marine mammal species, including sea otters, have been 
established using the same methods as those used by the National Marine 
Fisheries Service (NMFS) (Southall et al. 2019). These criteria are 
based on estimated levels of sound exposure capable of causing a 
permanent shift in hearing sensitivity (i.e., a permanent threshold 
shift (PTS) (NMFS 2018)). A PTS occurs when noise exposure causes hairs 
within the inner ear system to die (Ketten 2012). Although the effects 
of PTS are, by definition, permanent, PTS does not equate to total 
hearing loss.
    Sound exposure thresholds incorporate two metrics of exposure: the 
peak level of instantaneous exposure likely to cause PTS and the 
cumulative sound exposure level (SELCUM) during a 24-hour 
period. They also include weighting adjustments for the sensitivity of 
different species to varying frequencies. The PTS-based injury criteria 
were developed from theoretical extrapolation of observations of 
temporary threshold shifts (TTS) detected in lab settings during sound 
exposure trials (Finneran 2015). The TTS is a noise-induced threshold 
shift in hearing sensitivity that fully recovers over time (Finneran 
2015). Southall and colleagues (2019) predict that PTS for sea otters, 
which are included in the ``other marine carnivores'' category, will 
occur at 232 dB peak or 203 dB SELCUM for impulsive 
underwater sound and 219 dB SEL for nonimpulsive (continuous) 
underwater sound.
    Thresholds based on TTS have been used as a proxy for Level B 
harassment (i.e., 70 FR 1871, January 11, 2005; 71 FR 3260, January 20, 
2006; 73 FR 41318, July 18, 2008). Southall et al. (2007) derived TTS 
thresholds for pinnipeds based on 212 dB peak and 171 dB SEL. Exposures 
resulting in TTS in pinnipeds were found to range from 152 to 174 dB 
(183 to 206 dB SEL) (Kastak et al. 2005), with a persistent TTS, if not 
a PTS, after 60 seconds of 184 dB SEL (Kastak et al. 2008). Kastelein 
et al. (2012) found small but statistically significant TTSs at 
approximately 170 dB SEL (136 dB, 60 minutes) and 178 dB SEL (148 dB, 
15 minutes). Based on these findings, Southall et al. (2019) developed 
TTS thresholds for sea otters, which are included in the ``other marine 
carnivores'' category, of 188 dB SEL for impulsive sounds and 199 dB 
SEL for nonimpulsive sounds.
    The NMFS (2018) criteria do not identify thresholds for avoidance 
of Level B harassment. For pinnipeds (seals and sea lions), NMFS has 
adopted a 160-dB threshold for Level B harassment from exposure to 
impulsive noise and a 120-dB threshold for continuous noise (NMFS 1998; 
HESS 1999; NMFS 2018). These thresholds were developed from 
observations of mysticete (baleen) whales responding to airgun 
operations (e.g., Malme et al. 1983; Malme and Miles 1983; Richardson 
et al. 1986, 1995) and from equating Level B harassment with noise 
levels capable of causing TTS in lab settings. Southall et al. (2007, 
2019) assessed behavioral response studies and found considerable 
variability among pinnipeds. The authors determined that exposures 
between approximately 90 to 140 dB generally do not appear to induce 
strong behavioral responses from pinnipeds in water. However, they 
found behavioral effects, including avoidance, become more likely in 
the range between 120 and 160 dB, and most marine mammals showed some, 
albeit variable, responses to sound between 140 and 180 dB. Wood et al. 
(2012) adapted the approach identified in Southall et al. (2007) to 
develop a probabilistic scale for marine mammal taxa at which 10 
percent, 50 percent, and 90 percent of individuals exposed are assumed 
to produce a behavioral response. For many marine mammals, including 
pinnipeds, these response rates were set at sound pressure levels (SPL) 
of 140, 160, and 180 dB, respectively.
    We have evaluated these thresholds and determined that the Level B 
harassment threshold of 120 dB for nonimpulsive noise is not applicable 
to sea otters. The 120-dB threshold is

[[Page 59756]]

based on studies in which gray whales (Eschrichtius robustus) were 
exposed to experimental playbacks of industrial noise (Malme et al. 
1983; Malme and Miles 1983). During these playback studies, southern 
sea otter responses to industrial noise were also monitored (Riedman 
1983, 1984). Gray whales exhibited avoidance to industrial noise at the 
120-dB threshold; however, there was no evidence of disturbance 
reactions or avoidance in southern sea otters. Thus, given the 
different range of frequencies to which sea otters and gray whales are 
sensitive, the NMFS 120-dB threshold based on gray whale behavior is 
not appropriate for predicting sea otter behavioral responses, 
particularly for low-frequency sound.
    Based on the lack of sea otter disturbance response or any other 
reaction to the playback studies from the 1980s, as well as the absence 
of a clear pattern of disturbance or avoidance behaviors attributable 
to underwater sound levels up to about 160 dB resulting from low-
frequency broadband noise, we assume 120 dB is not an appropriate 
behavioral response threshold for sea otters exposed to continuous 
underwater noise.
    Based on the best available scientific information about sea otters 
and closely related marine mammals when sea otter data are limited, the 
FWS has set 160 dB of received underwater sound as a threshold for 
Level B take by disturbance for sea otters for this IHA. Exposure to 
in-water noise levels between 125 Hz and 38 kHz that are greater than 
160 dB--for both impulsive and nonimpulsive sound sources--will be 
considered by the FWS as Level B harassment. Thresholds for Level A 
harassment (which entails the potential for injury) for in-water sounds 
between 125 Hz and 38 kHz will be 232 dB peak or 203 dB SEL for 
impulsive sounds and 219 dB SEL for continuous sounds (table 1).

Airborne Sounds

    The NMFS (2018) guidance neither addresses thresholds for 
preventing injury or disturbance from airborne noise, nor provides 
thresholds for avoidance of Level B harassment. Conveyance of 
underwater noise into the air is of little concern since the effects of 
pressure release and interference at the water's surface reduce 
underwater noise transmission into the air. For activities that create 
both in-air and underwater sounds, we will estimate take based on 
parameters for underwater noise transmission. Considering sound energy 
travels more efficiently through water than through air, this 
estimation will also account for exposures to sea otters at the 
surface.

 Table 1--Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS) Thresholds Established by Southall
  et al. (2019) Through Modeling and Extrapolation for ``Other Marine Carnivores,'' Which Include Sea Otters *
----------------------------------------------------------------------------------------------------------------
                                                 TTS                                       PTS
                             -----------------------------------------------------------------------------------
                               nonimpulsive           impulsive          nonimpulsive           impulsive
                             -----------------------------------------------------------------------------------
                                  SELCUM         SELCUM      Peak SPL       SELCUM         SELCUM      Peak SPL
----------------------------------------------------------------------------------------------------------------
Air.........................             157          146          170             177          161          176
Water.......................             199          188          226             219          203          232
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* Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure
  level (SELCUM dB re 20 micropascal ([mu]Pa) in air and SELCUM dB re 1 [mu]Pa in water) for impulsive and
  nonimpulsive sounds, and unweighted peak sound pressure level (SPL) in air (dB re 20[mu]Pa) and water (dB
  1[mu]Pa) (impulsive sounds only).

Evidence From Sea Otter Studies

    Individual sea otters in Passage Canal will likely show a range of 
responses to noise from pile-driving activities. Some sea otters will 
likely dive, show startle responses, change direction of travel, or 
prematurely surface. Sea otters reacting to pile-driving activities may 
divert time and attention from biologically important behaviors, such 
as feeding and nursing pups. Sea otter responses to disturbance can 
result in energetic costs, which increases the amount of prey required 
by sea otters (Barrett 2019). This increased prey consumption may 
impact sea otter prey availability and cause sea otters to spend more 
time foraging and less time resting (Barrett 2019). Some sea otters may 
abandon the project area and return when the disturbance has ceased. 
Based on the observed movement patterns of sea otters (Lensink 1962; 
Kenyon 1969, 1981; Garshelis and Garshelis 1984; Riedman and Estes 
1990; Tinker and Estes 1996), we expect some individuals will respond 
to pile-driving activities by dispersing to nearby areas of suitable 
habitat; however other sea otters, especially territorial adult males, 
will not be displaced.
    Additional information on the evidence from studies about how sea 
otters may be affected by sound can be found in the supplemental 
information to this document (available as described above in 
ADDRESSES).

Consequences of Disturbance

    Information on the consequences of disturbance to sea otters can be 
found in the supplemental information to this document (available as 
described above in ADDRESSES).

Vessel Activities

    Vessel activity during the project includes the transit of three 
barges for materials and construction, all of which will remain on 
site, mostly stationary, to support the work; additionally, two skiffs 
will be used during the project: one for transporting workers short 
distances to the crane barge and the other for marine mammal monitoring 
during pile driving. Vessels will not be used extensively or over a 
long duration during the planned work; therefore, we do not anticipate 
that sea otters will experience changes in behavior indicative of 
tolerance or habituation.
    Additional information on vessel activities can be found in the 
supplemental information to this document (available as described above 
in ADDRESSES).

Effects on Sea Otter Habitat and Prey

    Information on the potential impacts of the specified activities on 
sea otter prey species can be found in the supplemental information to 
this document (available as described above in ADDRESSES).

Potential Impacts of the Specified Activities on Subsistence Uses

    The planned specified activities will occur near marine subsistence 
harvest areas used by Alaska Native peoples from Whittier and the 
surrounding areas. The majority of sea otter harvest in this area 
occurs more than 3.2

[[Page 59757]]

kilometers (km) (2 miles [mi]) outside of Whittier. Since 2012, there 
have been 75 sea otters harvested in the Whittier area, and most of 
those were taken prior to 2017. From 2018 through 2021, only eight sea 
otters were harvested from the Whittier area.
    The planned project would occur within the Whittier city limits, 
where firearm use is prohibited. The area potentially affected by the 
planned project does not significantly overlap with current subsistence 
harvest areas. Construction activities will not preclude access to 
hunting areas or interfere in any way with individuals wishing to hunt. 
Despite no conflict with subsistence use being anticipated, the FWS 
will conduct outreach with potentially affected communities to see 
whether there are any questions, concerns, or potential conflicts 
regarding subsistence use in those areas. If any conflicts are 
identified in the future, TMC will develop a plan of cooperation 
specifying the steps necessary to minimize any effects the project may 
have on subsistence harvest.

Estimated Take

Definitions of Incidental Take Under the Marine Mammal Protection Act

    Below we provide definitions of potential types of take of northern 
sea otters. The FWS does not anticipate and is not proposing to 
authorize lethal take as a part of this proposed IHA, nor did the 
applicant request authorization of lethal take; however, the 
definitions of these take types are provided for context and 
background.
    Lethal Take--Human activity may result in biologically significant 
impacts to northern sea otters. In the most serious interactions, human 
actions can result in the mortality of sea otters.
    Level A Harassment--Human activity may result in the injury of sea 
otters. Level A harassment for nonmilitary readiness activities is 
defined as any act of pursuit, torment, or annoyance that has the 
potential to injure a marine mammal or marine mammal stock in the wild.
    Level B Harassment--Level B harassment for nonmilitary readiness 
activities means any act of pursuit, torment, or annoyance that has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behaviors or activities, including, but not 
limited to, migration, breathing, nursing, feeding, or sheltering. 
Human-caused changes in behavior that disrupt biologically significant 
behaviors or activities for the affected animal indicate take by Level 
B harassment under the MMPA.
    The FWS has identified the following sea otter behaviors as 
indicative of possible Level B harassment:
     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 also be indicative of Level B harassment. 
Relatively minor changes in behavior such as increased vigilance or a 
short-term change in direction of travel are not likely to disrupt 
biologically important behavioral patterns, and the FWS does not view 
such minor changes in behavior as indicative of Level B harassment.

Calculating Take

    We assumed all animals exposed to underwater sound levels that meet 
the acoustic exposure criteria defined above in Exposure Thresholds 
will experience take by Level A harassment or Level B harassment due to 
exposure to underwater noise. Spatially explicit zones of 
ensonification were established around the planned construction 
location to estimate the number of otters that may be exposed to these 
sound levels. We determined the number of otters present in the 
ensonification zones using density information generated by Esslinger 
et al. (2021).
    The project can be divided into four major components: DTH 
drilling, vibratory drilling, pile driving using an impact driver, and 
skiff use to support construction. Each of these components will 
generate a different type of in-water noise. Vibratory drilling and the 
use of skiffs will produce nonimpulsive or continuous noise; impact 
driving will produce impulsive noise; and DTH drilling is considered to 
produce both impulsive and continuous noise (NMFS 2020).
    The level of sound anticipated from each project component was 
established using recorded data from several sources listed in tables 2 
through 5. We used the empirical data from those proxy projects with 
the NMFS Technical Guidance and User Spreadsheet (NMFS 2018, 2020) to 
determine the distance at which sound levels would attenuate to Level A 
harassment thresholds (table 1). To estimate the distances at which 
sounds would attenuate to Level B harassment thresholds (table 1), we 
used the data from the proxy projects with the NMFS-recommended 
transmission loss coefficient of 15 for coastal pile-driving activities 
in a practical spreading loss model (NMFS 2020) to determine the 
distance at which sound levels attenuate to 160 dB re 1 [mu]Pa. The 
weighting factor adjustment included in the NMFS user spreadsheet 
accounts for sounds created in portions of an organism's hearing range 
where they have less sensitivity. We used the weighting factor 
adjustment for otariid pinnipeds as they are the closest available 
physiological and anatomical proxy for sea otters. The spreadsheet also 
incorporates a transmission loss coefficient, which accounts for the 
reduction in sound level outward from a sound source. We used the NMFS-
recommended transmission loss coefficient of 15 for coastal pile-
driving activities to indicate practical spread (NMFS 2020).
    We calculated the harassment zones for DTH drilling with input from 
NMFS. The SPLs produced by DTH drilling were provided by NMFS in 2022 
via correspondence with Solstice Alaska Consulting, who created the 
application for this IHA on behalf of TMC, as well as from the NMFS 
proposed IHA for this project in 2023. We then used the provided SPLs 
with the NMFS Technical Guidance and User Spreadsheet (NMFS 2018, 2020) 
to determine the distance at which these sounds would attenuate to 
Level A harassment thresholds. To estimate the distances at which 
sounds would attenuate to Level B harassment thresholds, we used the 
provided SPLs with a NMFS-recommended transmission loss coefficient of 
15 for coastal pile-driving activities in a practical spreading loss 
model (NMFS 2020) to determine the distance at which sound levels 
attenuate to 160 dB re 1 [mu]Pa. To ensure the most conservative 
harassment thresholds, peak SPL of 194 dB re 1 [mu]Pa (Heyvaert and 
Reyff 2021) was included in the calculations of Level B harassment 
thresholds for DTH pile driving. However, due to the differences in how 
PTS and TTS thresholds are calculated, as well as limited data of 
underwater

[[Page 59758]]

SPLs from DTH drilling, the resultant Level A isopleths for DTH 
installation of 122-cm (48-in) steel piles are larger than the Level B 
isopleths.

    Table 2--Summary of Sound Level, Timing of Sound Production, Distance From Sound Source to Below Level A
   Harassment and Level B Harassment Thresholds, Days of Impact, Sea Otters in Level A and Level B Harassment
    Ensonification Area, and Total Otters Expected To Be Harassed Through Behavioral Disturbance by Vibratory
                                                    Drilling
----------------------------------------------------------------------------------------------------------------
                                    91-cm (36-in)        91-cm (36-in)
           Pile size                 (temporary)-        (temporary)-        91-cm (36-in)      122-cm (48-in)
                                     installation           removal           (permanent)         (permanent)
----------------------------------------------------------------------------------------------------------------
Total number of piles..........  15.................  15................  7.................  8.
----------------------------------------------------------------------------------------------------------------
Sound level....................                166 dB re 1[mu]Pa at 10 m (RMS)                168.2 dB re
                                                                                               1[mu]Pa at 10 m
                                                                                               (RMS).
----------------------------------------------------------------------------------------------------------------
Source.........................                        NAVFAC \a\ 2015                        Austin et al.
                                                                                               2016.
----------------------------------------------------------------------------------------------------------------
Timing per pile................  10 minutes/pile....  10 minutes/pile...  15 minutes/pile...  15 minutes/pile.
Maximum number of piles per day  4..................  4.................  4.................  2.
Maximum number of days of        4..................  4.................  2.................  4.
 activity.
----------------------------------------------------------------------------------------------------------------
Sea otter density..............                               2.03 sea otters/km\2\
----------------------------------------------------------------------------------------------------------------
Distance to below Level A        0.5 meters.........  0.5 meters........  0.6 meters........  0.6 meters.
 harassment threshold.
Level A area (km\2\)...........  0.000001...........  0.000001..........  0.000001..........  0.000001.
Potential sea otters affected    0.000002...........  0.000002..........  0.000002..........  0.000002.
 by Level A sound per day.
Potential sea otters affected    0..................  0.................  0.................  0.
 by Level A sound per day
 (rounded).
----------------------------------------------------------------------------------------------------------------
    Total potential Level A      0..................  0.................  0.................  0.
     harassment events.
----------------------------------------------------------------------------------------------------------------
Distance to below Level B        25 meters..........  25 meters.........  25 meters.........  35 meters.
 harassment threshold.
Level B area (km\2\)...........  0.002..............  0.0020............  0.0020............  0.0038.
Potential sea otters affected    0.0040.............  0.0040............  0.004.............  0.0078.
 by Level B sound per day.
Potential sea otters affected    0..................  0.................  0.................  0.
 by Level B sound per day
 (rounded).
----------------------------------------------------------------------------------------------------------------
    Total potential Level B      0..................  0.................  0.................  0.
     harassment events.
----------------------------------------------------------------------------------------------------------------
\a\ Naval Facilities Engineering Command.


  Table 3--Summary of Sound Level, Timing of Sound Production, Distance
  From Sound Source to Below Level A Harassment and Level B Harassment
Thresholds, Days of iMpact, Sea Otters in Level A and Level B Harassment
  Ensonification Area, and Total Otters Expected To Be Harassed Through
              Behavioral Disturbance by Impact Pile Driving
------------------------------------------------------------------------
                                     91-cm (36-in)      122-cm (48-in)
            Pile size                 (permanent)         (permanent)
------------------------------------------------------------------------
Total number of piles...........  7.................  8.
Sound level.....................  184 dB (SEL)/192    186.7 dB (SEL)/
                                   dB (RMS)/211 dB     198.6 dB (RMS)/
                                   (peak) re 1[mu]Pa   212 dB (peak) re
                                   at 10 m.            1[mu]Pa at 10 m.
Source..........................  NAVFAC 2015.......  Austin et al.
                                                       2016.
Timing per pile.................  45 minutes/pile;    60 minutes/pile;
                                   1,800 strikes/      2,400 strikes/
                                   pile.               pile.
Maximum number piles per day....  4.................  2.
Maximum number of days of         2.................  4.
 activity.
------------------------------------------------------------------------
Sea otter density...............          2.03 sea otters/km\2\.
------------------------------------------------------------------------
Distance to below Level A         169.2 meters......  195.4 meters.
 harassment threshold.
Level A area (km\2\)............  0.0718............  0.1199.
Potential sea otters affected by  0.1458............  0.2435.
 Level A sound per day.
Potential sea otters affected by  1.................  1.
 Level A sound per day (rounded).
------------------------------------------------------------------------
    Total potential Level A       2.................  4.
     harassment events.
------------------------------------------------------------------------
Distance to below Level B         1,359 meters......  3,744 meters.
 harassment threshold.
Level B area (km\2\)............  1.9161............  7.8846.
Potential sea otters affected by  3.8897............  16.0058
 Level B sound per day.
Potential sea otters affected by  4.................  16.
 Level B sound per day (rounded).
------------------------------------------------------------------------
    Total potential Level B       8.................  64.
     harassment events.
------------------------------------------------------------------------


[[Page 59759]]


    Table 4--Summary of Sound Level, Timing of Sound Production, Distance From Sound Source to Below Level A
   Harassment and Level B Harassment Thresholds, Days of Impact, Sea Otters in Level A and Level B Harassment
  Ensonification Area, and Total Otters Expected To Be Harassed Through Behavioral Disturbance by Down-the-Hole
                                                    Drilling
----------------------------------------------------------------------------------------------------------------
                                            91-cm (36-in)            91-cm (36-in)            122-cm (48-in)
              Pile size                      (temporary)              (permanent)              (permanent)
----------------------------------------------------------------------------------------------------------------
Total number of piles...............  10 (installation only)..  7......................  8.
----------------------------------------------------------------------------------------------------------------
Sound level.........................  164 dB (SEL)/174 dB (RMS)/194 (peak) re 1[mu]Pa    171 dB (SEL)/174 (RMS)/
                                       at 10 m.                                           194 (peak) dB re
                                                                                          1[mu]Pa at 10 m.
----------------------------------------------------------------------------------------------------------------
Source..............................  Reyff and Heyvaert 2019; Reyff 2020; Denes et al.  SolsticeAK 2022;
                                       2019; Heyvaert and Reyff 2021; NMFS 2023.          Heyvaert and Reyff
                                                                                          2021; NMFS 2023.
----------------------------------------------------------------------------------------------------------------
Timing per pile.....................  60 minutes/pile.........  150 minutes/pile.......  150 minutes/pile.
Maximum number piles per day........  4.......................  2......................  2.
Maximum number of days of activity..  3.......................  4......................  4.
----------------------------------------------------------------------------------------------------------------
Sea otter density...................                            2.03 sea otters/km\2\.
----------------------------------------------------------------------------------------------------------------
Distance to below Level A harassment  57.9 meters.............  67.1 meters............  196.6 meters.\a\
 threshold.
Level A area (km\2\)................  0.0105..................  0.0141.................  0.1214.
Potential sea otters affected by      0.0214..................  0.0287.................  0.2465.
 Level A sound per day.
Potential sea otters affected by      1.......................  1......................  1.
 Level A sound per day (rounded).
----------------------------------------------------------------------------------------------------------------
    Total potential Level A           3.......................  4......................  4.
     harassment events.
----------------------------------------------------------------------------------------------------------------
Distance to below Level B harassment  85.8 meters.............  85.8 meters............  85.8 meters.\a\
 threshold.
Level B area (km\2\)................  0.0231..................  0.0231.................  0.0231.
Potential sea otters affected by      0.0469..................  0.0469.................  0.0469.
 Level B sound per day.
Potential sea otters affected by      1.......................  1......................  1.
 Level B sound per day (rounded).
----------------------------------------------------------------------------------------------------------------
    Total potential Level B           3.......................  4......................  4.
     harassment events.
----------------------------------------------------------------------------------------------------------------
\a\ Due to differences in how PTS and TTS thresholds are calculated, the Level A isopleths are larger than the
  Level B isopleths.


  Table 5--Summary of Sound Level, Timing of Sound Production, Distance
  From Sound Source to Below Level A Harassment and Level B Harassment
Thresholds, Days of Impact, Sea Otters in Level A and Level B Harassment
  Ensonification Area, and Total Otters Expected To Be Harassed Through
                 Behavioral Disturbance by Use of Skiffs
------------------------------------------------------------------------
                                                        Worker transit
          Sound source             Monitoring skiff          skiff
------------------------------------------------------------------------
Sound level.....................  175 dB (RMS) re     175 dB (RMS) re
                                   1[mu]Pa at 1 m.     1[mu]Pa at 1 m.
------------------------------------------------------------------------
Source..........................    Richardson et al. 1995; Kipple and
                                               Gabriele 2007.
------------------------------------------------------------------------
Number of days of vessel use....  31................  31.
------------------------------------------------------------------------
Sea otter density...............          2.03 sea otters/km\2\.
------------------------------------------------------------------------
Distance to below Level A         0 meters..........  0 meters.
 harassment threshold.
Level A area (km\2\)............  0.................  0.
Potential sea otters affected by  0.................  0.
 Level A sound per day.
Potential sea otters affected by  0.................  0.
 Level A sound per day (rounded).
------------------------------------------------------------------------
    Total potential Level A       0.................  0.
     harassment events.
------------------------------------------------------------------------
Distance to below Level B         10 meters.........  10 meters.
 harassment threshold.
Level B area (km\2\)............  0.2832............  0.0095.
Potential sea otters affected by  0.5748............  0.0192.
 Level B sound per day.
Potential sea otters affected by  1.................  1.
 Level B sound per day (rounded).
------------------------------------------------------------------------

[[Page 59760]]

 
    Total potential Level B       31................  31.
     harassment events.
------------------------------------------------------------------------

    Sound levels for all sources are unweighted and given in dB re 1 
[mu]Pa. Nonimpulsive sounds are in the form of mean maximum root mean 
square (RMS) SPL as it is more conservative than SELCUM or 
peak SPL for these activities. Impulsive sound sources are in the form 
of SEL for a single strike.
    To determine the number of sea otters that may experience in-water 
sounds >160 dB re 1[mu]Pa due to pile driving, we multiplied the area 
ensonified to >160 dB re 1[mu]Pa by the density of animals (2.03 sea 
otters per square kilometer (km\2\)) derived from surveys conducted of 
Prince William Sound (Esslinger et al. 2021). We applied the same 
methodology to determine the number of sea otters that may experience 
sounds capable of causing PTS. The number of sea otters expected to be 
exposed to such sound levels can be found in tables 2 through 5. To 
calculate the area ensonified for each type of pile-driving activity, 
the coordinates of the piles were mapped in ArcGIS Pro. We used a 
representative pile of each size around which to map the Level A 
harassment and Level B harassment zones. We chose representative piles 
that were farthest from shore so that the zones that are intercepted by 
land have the largest in-water areas possible. The majority of these 
radii are small enough that their defined circles will fall entirely in 
the water, and in these instances, the area was calculated as [pi]r\2\. 
The exceptions are the Level A and Level B zones generated by impact 
pile driving the 91-cm (36-in) permanent piles as well as the Level B 
zone generated by impact pile driving the 122-cm (48-in) piles; for 
these, we used ArcGIS Pro to map and calculate the area of the water 
ensonified by those activities.
    The area ensonified by the worker transit skiff was estimated by 
multiplying the vessel's anticipated daily track length by twice the 
160 dB radius plus [pi]r\2\ to account for the rounded ends of the 
track line. It was estimated that the distance of each trip would be no 
more than 457.2 m (1,500 ft). The worker transit skiff transports crew 
between shore and the work platform. It will be in use the same days 
that pile driving occurs but is not expected to be used while piles are 
being driven.
    The monitoring skiff will travel in a triangle of perimeter 
approximately 7 km (4.3 mi) between Emerald Island, the north shore of 
Passage Canal, and Gradual Point during pile driving activities, but 
outside the largest Level B harassment threshold. To estimate the area 
ensonified by the monitoring skiff, we used ArcGIS Pro to plot the 
points of the triangle, map the track line between those points, and 
apply a buffer of 10 m (33 ft; the 160-dB radius) on either side of the 
track line.
    We assumed that the different types of pile-driving activities 
would occur sequentially and that the total number of days of work 
would equal the sum of the number of days required to complete each 
type of pile-driving activity. While it is possible that on some days 
more than one type of activity will take place, which would reduce the 
number of days of exposure within a year, we cannot know this 
information in advance. As such, the estimated number of days and, 
therefore, exposures per year is the maximum possible for the planned 
work. Where the number of exposures expected per day was zero to three 
or more decimal places (i.e., <0.00X), the number of exposures per day 
was assumed to be zero.
    In order to minimize exposure of sea otters to sounds above Level A 
harassment thresholds, TMC will implement shutdown zones ranging from 
10 to 200 m (33 to 656 ft), based on the pile size and type of pile 
driving or marine construction activity, where operations will cease 
should a sea otter enter or approach the specified zone. Soft-start and 
zone clearance prior to startup will also limit the exposure of sea 
otters to sound levels that could cause PTS. However, TMC has 
requested, and the FWS proposes to authorize, small numbers of take by 
Level A harassment during impact pile driving and DTH drilling.
    Although sea otters are non-migratory, they typically move amongst 
focal areas within their home ranges to rest and forage (Garshelis and 
Garshelis 1984; Laidre et al. 2009). It is possible that, given the 
large variability in individual home range sizes and the potential for 
up to daily movement in and out of foraging or resting areas, different 
individual sea otters could be found within the ensonification zone 
each day of the project. Thus, the FWS conservatively assumes that the 
162 estimated harassment events may impact up to 162 different sea 
otters.

Critical Assumptions

    We estimate that 145 takes of 145 sea otters by Level B harassment 
and 17 takes of 17 sea otters by Level A harassment may occur due to 
TMC's planned cruise ship dock construction activities. In order to 
conduct this analysis and estimate the potential amount of take by 
harassment, several critical assumptions were made.
    Level B harassment is equated herein with behavioral responses that 
indicate harassment or disturbance. There is likely a portion of 
animals that respond in ways that indicate some level of disturbance 
but do not experience biologically significant consequences.
    We used the sea otter density for the Whittier area from surveys 
and analyses conducted by Esslinger et al. (2021). Methods and 
assumptions for these surveys can be found in the original publication.
    We used sound source verification from recent pile-driving 
activities in a number of locations within and beyond Alaska to 
generate sound level estimates for construction activities. 
Environmental conditions in these locations, including water depth, 
substrate, and ambient sound levels are similar to those in the project 
location, but not identical. Further, estimation of ensonification 
zones were based on sound attenuation models using a practical 
spreading loss model. These factors may lead to actual sound values 
differing slightly from those estimated here.
    Finally, the pile-driving activities described here will also 
create in-air noise. Because sea otters spend over half of their day 
with their heads above water (Esslinger et al. 2014), they will be 
exposed to an increase in-air noise from construction equipment. 
However, we have calculated Level B harassment with the assumption that 
an individual may be harassed only one time per 24-

[[Page 59761]]

hour period, and underwater sound levels will be more disturbing and 
extend farther than in-air noise. Thus, while sea otters may be 
disturbed by noise both in-air and underwater, we have relied on the 
more conservative underwater estimates.

Sum of Harassment From All Sources

    The applicant plans to conduct pile driving and marine construction 
activities in Whittier, Alaska, over the course of a year from the date 
of issuance of the IHA. A summary of total estimated take during the 
project by source is provided in table 6.

       Table 6--Total Estimated Takes by Source of Level A Harassment and Level B Harassment of Sea Otters
----------------------------------------------------------------------------------------------------------------
                                                    Sea otters    Total takes of    Sea otters    Total takes of
                                  Number of days    exposed per    sea otters by    exposed per    sea otters by
             Source                 of activity   day to Level A      Level A     day to Level B      Level B
                                                    harassment      harassment      harassment      harassment
----------------------------------------------------------------------------------------------------------------
Vibratory drilling:
    91-cm (36-in) (temporary)--                4               0               0               0               0
     installation...............
    91-cm (36-in) (temporary)--                4               0               0               0               0
     removal....................
    91-cm (36-in) (permanent)...               2               0               0               0               0
    122-cm (48-in) (permanent)..               4               0               0               0               0
Impact drilling:
    91-cm (36-in) (permanent)...               2               1               2               4               8
    122-cm (48-in) (permanent)..               4               1               4              16              64
Down-the-hole drilling:
    91-cm (36-in) (temporary)--                3               1               3               1               3
     installation...............
    91-cm (36-in) (permanent)...               4               1               4               1               4
    122-cm (48-in) (permanent)..               4               1               4               1               4
Skiff use:
    Monitoring skiff............              31               0               0               1              31
    Worker transit skiff........              31               0               0               1              31
                                 -------------------------------------------------------------------------------
    Totals......................              93               5              17              25             145
----------------------------------------------------------------------------------------------------------------

    Over the course of the project, we estimate 145 instances of take 
by Level B harassment of northern sea otters from the Southcentral 
Alaska stock due to behavioral responses and/or TTS associated with 
noise exposure. Although multiple instances of Level B harassment of 
individual sea otters are possible, these events are unlikely to have 
significant consequences for the health, reproduction, or survival of 
affected animals and therefore would not rise to the level of an injury 
or Level A harassment.
    The use of soft-start procedures, zone clearance prior to startup, 
and shutdown zones is likely to decrease both the number of sea otters 
exposed to sounds above Level A harassment thresholds and the exposure 
time of any sea otters venturing into a Level A harassment zone. This 
reduces the likelihood of losses of hearing sensitivity that might 
impact the health, reproduction, or survival of affected animals. 
Despite the implementation of mitigation measures, it is anticipated 
that some sea otters will experience Level A harassment via exposure to 
underwater sounds above threshold criteria during impact and DTH pile-
driving activities. Due to sea otters' small body size and low profile 
in the water, as well as the relatively large size of the Level A 
harassment zone associated with these activities, we anticipate that 
sea otters will at times avoid detection before entering Level A 
harassment zones for those activities. We anticipate that protected 
species observers (PSO) will be able to reliably detect and prevent 
take by Level A harassment of sea otters up to 10 m away; conversely, 
we anticipate that at distances greater than 10 m, sea otters will at 
times avoid detection. Throughout the project, we estimate 17 instances 
of take by Level A harassment of sea otters.

Determinations and Findings

    Sea otters exposed to sound from the specified activities are 
likely to respond with temporary behavioral modification or 
displacement. The specified activities could temporarily interrupt the 
feeding, resting, and movement of sea otters. Because activities will 
occur during a limited amount of time and in a localized region, the 
impacts associated with the project are likewise temporary and 
localized. The anticipated effects are short-term behavioral reactions 
and displacement of sea otters near active operations.
    Sea otters that encounter the specified activity may exert more 
energy than they would otherwise, due to temporary cessation of 
feeding, increased vigilance, and retreating from the project area. We 
expect that affected sea otters will tolerate this exertion without 
measurable effects on health or reproduction. Most of the anticipated 
takes will be due to short-term Level B harassment in the form of TTS, 
startling reactions, or temporary displacement. While mitigation 
measures incorporated into TMC's request will reduce occurrences of 
Level A harassment to the extent practicable, a small number of take by 
Level A harassment would be authorized for impact and DTH pile-driving 
activities, which have Level A harassment zone radii ranging in size 
from 57.9 to 196.6 m (190 to 645 ft).
    With the adoption of the mitigation measures incorporated in TMC's 
request and required by this proposed IHA, anticipated take was 
reduced. Those mitigation measures are further described below.

Small Numbers

    To assess whether the authorized incidental taking would be limited 
to ``small numbers'' of marine mammals, the FWS uses a proportional 
approach that considers whether the estimated number of marine mammals 
to be subjected to incidental take is small relative to the population 
size of the species or stock. Here, predicted levels of take were 
determined based on the estimated density of sea otters in the project 
area and ensonification zones developed using empirical evidence from 
similar geographic areas.
    We estimate that TMC's specified activities in the specified 
geographic region will take no more than 145 takes of 145 sea otters by 
Level B harassment and 17 takes of 17 sea otters by Level A harassment 
during the 1-year period of this proposed IHA (see Sum of Harassment 
from All Sources). Take of 162 animals is 0.7 percent of the best 
available estimate of the current Southcentral Alaska stock size of 
21,617 animals (Esslinger et al. 2021) ((162/21,617)x100[ap]0.7) and 
represents a

[[Page 59762]]

``small number'' of sea otters of that stock.

Negligible Impact

    We propose a finding that any incidental take by harassment 
resulting from the specified activities cannot be reasonably expected 
to, and is not reasonably likely to, adversely affect the sea otter 
through effects on annual rates of recruitment or survival and will, 
therefore, have no more than a negligible impact on the Southcentral 
Alaska stock of northern sea otters. In making this finding, we 
considered the best available scientific information, including the 
biological and behavioral characteristics of the species, the most 
recent information on species distribution and abundance within the 
area of the specified activities, the current and expected future 
status of the stock (including existing and foreseeable human and 
natural stressors), the potential sources of disturbance caused by the 
project, and the potential responses of marine mammals to this 
disturbance. In addition, we reviewed applicant-provided materials, 
information in our files and datasets, published reference materials, 
and species experts.
    Sea otters are likely to respond to planned activities with 
temporary behavioral modification or temporary displacement. These 
reactions are not anticipated to have consequences for the long-term 
health, reproduction, or survival of affected animals. Most animals 
will respond to disturbance by moving away from the source, which may 
cause temporary interruption of foraging, resting, or other natural 
behaviors. Affected animals are expected to resume normal behaviors 
soon after exposure with no lasting consequences. Sea otters may move 
in and out of the project area during pile driving activities, leading 
to as many as 162 individuals experiencing one day of exposure. 
However, it is possible that an individual may enter the ensonification 
area more than once during the project. At most, if the same sea otter 
enters the ensonification area every day that pile driving occurs, the 
sea otter would be exposed to pile driving and marine construction 
noise for up to 31 days. However, injuries (i.e., Level A harassment or 
PTS) due to chronic sound exposure are estimated to occur at a longer 
time scale (Southall et al. 2019). The area that will experience noise 
greater than Level B thresholds due to pile driving is small (less than 
0.13 km\2\), and an animal that may be disturbed could escape the noise 
by moving to nearby quiet areas. Further, sea otters spend over half of 
their time above the surface during the summer months (Esslinger et al. 
2014), and likely no more than 70 percent of their time foraging during 
winter months (Gelatt et al. 2002); thus, their ears will not be 
exposed to continuous noise, and the amount of time it may take for 
permanent injury is considerably longer than that of mammals primarily 
under water. Some animals may exhibit some of the stronger responses 
typical of Level B harassment, such as fleeing, interruption of 
feeding, or flushing from a haulout. These responses could have 
temporary biological impacts for affected individuals but are not 
anticipated to result in measurable changes in survival or 
reproduction.
    The total number of animals affected, and severity of impact is not 
sufficient to change the current population dynamics at the stock 
scale. Although the specified activities may result in approximately 
162 incidental takes of up to 162 sea otters from the Southcentral 
Alaska stock, we do not expect this level of harassment to affect 
annual rates of recruitment or survival or result in adverse effects on 
the stock.
    Currently, the best available scientific information indicates that 
the density of sea otters in the project area is 2.03 sea otters/km\2\ 
(Esslinger et al. 2021). However, during similar marine construction 
and pile-driving activities in Whittier under an existing IHA, PSOs 
collected data which indicate that the proposed project activities may 
be less impactful than estimated (table 7). No recorded takes by Level 
A harassment occurred during similar work in Whittier between May 2023 
and February 2024, and only 5 takes by Level B harassment occurred over 
those 10 months.

 Table 7--Total Numbers of Observations, Individuals, and Takes by Level A Harassment and Level B Harassment of
                                        Sea Otters Under the Initial IHA
----------------------------------------------------------------------------------------------------------------
                                                                     Number of       Number of       Number of
             Year                     Month          Number of    individual sea  takes by Level  takes by Level
                                                     sightings        otters       A harassment    B harassment
----------------------------------------------------------------------------------------------------------------
2023..........................  May.............               1               6               0               0
                                June............               1               1               0               0
                                July............               1               1               0               0
                                August..........               5               5               0               0
                                September.......              13              13               0               3
                                October.........              18              22               0               2
                                November........               7              11               0               0
                                December........               9              15               0               0
2024..........................  January.........               6               3               0               0
                                February........               1               1               0               0
                                                 ---------------------------------------------------------------
    Total.....................  ................              62              78               0               5
----------------------------------------------------------------------------------------------------------------

    Our proposed finding of negligible impact applies to incidental 
take associated with the specified activities as mitigated by the 
avoidance and minimization measures identified in TMC's mitigation and 
monitoring plan. These mitigation measures are designed to minimize 
interactions with and impacts to sea otters. These measures and the 
monitoring and reporting procedures are required for the validity of 
our finding and are a necessary component of the proposed IHA. For 
these reasons, we propose a finding that the specified project will 
have a negligible impact on the Southcentral Alaska stock of northern 
sea otters.

Least Practicable Adverse Impacts

    We find that the mitigation measures required by this proposed IHA 
will affect the least practicable adverse impacts on the stocks from 
any incidental take likely to occur in association with the specified 
activities. In making this finding, we considered the biological 
characteristics of sea otters, the nature of the specified activities, 
the potential effects of the activities on sea otters, the documented 
impacts of similar activities on sea otters, and alternative mitigation 
measures.
    In evaluating what mitigation measures are appropriate to ensure 
the

[[Page 59763]]

least practicable adverse impact on species or stocks and their 
habitat, as well as subsistence uses, we considered the manner and 
degree to which the successful implementation of the measures are 
expected to achieve this goal. We considered the nature of the 
potential adverse impact being mitigated (likelihood, scope, range), 
the likelihood that the measures will be effective if implemented, and 
the likelihood of effective implementation. We also considered the 
practicability of the measures for applicant implementation (e.g., 
cost, impact on operations). We assessed whether any additional, 
practicable requirements could be implemented to further reduce 
effects, but did not identify any.
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, TMC will implement mitigation measures, 
including the following:
     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 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;
     Development of a marine mammal monitoring and mitigation 
plan;
     Establishment of shutdown and monitoring zones;
     Visual mitigation monitoring by designated PSOs;
     Site clearance before startup;
     Soft-start procedures; and
     Shutdown procedures.

Impact on Subsistence Use

    The project will not preclude access to harvest areas or interfere 
with the availability of sea otters for harvest. Additionally, the 
planned cruise ship berth and associated facilities are located within 
the City of Whittier, where firearm use is prohibited. We therefore 
propose a finding that TMC's anticipated harassment will not have an 
unmitigable adverse impact on the availability of any stock of northern 
sea otters for taking for subsistence uses. In making this proposed 
finding, we considered the timing and location of the planned 
activities and the timing and location of subsistence harvest 
activities in the project area.

Monitoring and Reporting

    The purposes of the monitoring requirements are to document and 
provide data for assessing the effects of specified activities on sea 
otters; to ensure that take is consistent with that anticipated in the 
small numbers, negligible impact, and subsistence use analyses; and to 
detect any unanticipated effects on the species. Monitoring plans 
include steps to document when and how sea otters are encountered and 
their numbers and behaviors during these encounters. This information 
allows the FWS to measure encounter rates and trends and to estimate 
numbers of animals potentially affected. To the extent possible, 
monitors will record group size, age, sex, reaction, duration of 
interaction, and closest approach to the project activity.
    As proposed, monitoring activities will be summarized and reported 
in formal reports. TMC must submit monthly reports for all months 
during which noise-generating work takes place as well as a final 
monitoring report that must submitted no later than 90 days after the 
expiration of the IHA. We will require approval of the monitoring 
results for continued operation under the IHA.
    We find that these proposed monitoring and reporting requirements 
to evaluate the potential impacts of planned activities will ensure 
that the effects of the activities remain consistent with the rest of 
the findings.

Required Determinations

National Environmental Policy Act

    We have prepared a draft environmental assessment in accordance 
with the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et 
seq.). We have preliminarily concluded that authorizing the nonlethal, 
incidental, unintentional take by Level B harassment of up to 145 takes 
and by Level A harassment of up to 17 takes from the Southcentral 
Alaska stock of northern sea otters in the specified geographic region 
during the specified activities during the regulatory period would not 
significantly affect the quality of the human environment and, thus, 
preparation of an environmental impact statement for this proposed IHA 
is not required by section 102(2) of NEPA or its implementing 
regulations. We are accepting comments on the draft environmental 
assessment as specified above in DATES and ADDRESSES.

Endangered Species Act

    Under the Endangered Species Act (ESA; 16 U.S.C. 1536(a)(2)), all 
Federal agencies are required to ensure the actions they authorize are 
not likely to jeopardize the continued existence of any threatened or 
endangered species or result in destruction or adverse modification of 
critical habitat. The specified activities would occur entirely within 
the range of the Southcentral Alaska stock of northern sea otters, 
which is not listed as threatened or endangered under the ESA. The 
authorization of incidental take of northern sea otters and the 
measures included in the proposed IHA would not affect other listed 
species or designated critical habitat.

Government-to-Government Consultation

    It is our responsibility to communicate and work directly on a 
Government-to-Government basis with federally recognized Alaska Native 
Tribes and Alaska Native Claims Settlement Act (ANCSA) corporations in 
developing programs for healthy ecosystems. We seek their full and 
meaningful participation in evaluating and addressing conservation 
concerns for protected species. It is our goal to remain sensitive to 
Alaska Native culture, and to make information available to Alaska 
Tribal organizations and communities. Our efforts are guided by the 
following policies and directives:
    (1) The Native American Policy of the Service (January 20, 2016);
    (2) The Alaska Native Relations Policy (currently in draft form);
    (3) Executive Order 13175 (January 9, 2000);
    (4) Department of the Interior Secretary's Orders 3206 (June 5, 
1997), 3225 (January 19, 2001), 3317 (December 1, 2011), and 3342 
(October 21, 2016);
    (5) The Alaska Government-to-Government Policy (a departmental 
memorandum issued January 18, 2001); and
    (6) the Department of the Interior's policies on consultation with 
Alaska Native Tribes and organizations.
    We have evaluated possible effects of the specified activities on 
federally recognized Alaska Native Tribes and organizations. The FWS 
has determined that, due to this project's locations and activities, 
the Tribal organizations and communities near Whittier, Alaska, as well 
as relevant Alaska Native Claims Settlement Act (ANCSA) corporations, 
will not be impacted. Regardless, we will be reaching out to the Tribal 
organizations and ANCSA corporations

[[Page 59764]]

to inform them of the availability of this proposed IHA and offer them 
the opportunity to consult.
    We invite continued discussion, either about the project and its 
impacts or about our coordination and information exchange, throughout 
the IHA process.

Paperwork Reduction Act

    This rule does not contain any new collection of information that 
requires approval by the Office of Management and Budget (OMB) under 
the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). OMB has 
previously approved the information collection requirements associated 
with IHAs and assigned OMB Control Number 1018-0194 (expires August 31, 
2026). An agency may not conduct or sponsor, and a person is not 
required to respond to, a collection of information unless it displays 
a currently valid OMB control number.

Proposed Authorization

    We propose to authorize the nonlethal, incidental take by Level A 
harassment and Level B harassment of 162 northern sea otters from the 
Southcentral Alaska stock. Authorized take may be caused by pile 
driving and marine construction activities conducted by TMC in 
Whittier, Alaska, between July 19, 2024, and July 18, 2025. We do not 
anticipate or authorize any lethal take to sea otters resulting from 
these activities.

A. General Conditions for This IHA

    (1) Activities must be conducted in the manner described in the 
March 18, 2024, revised request from TMC for an IHA and in accordance 
with all applicable conditions and mitigation measures. The taking of 
sea otters whenever the required conditions, mitigation, monitoring, 
and reporting measures are not fully implemented as required by the IHA 
is prohibited. Failure to follow the measures specified both in the 
revised request and within this proposed authorization may result in 
the modification, suspension, or revocation of the IHA.
    (2) If project activities cause unauthorized take (i.e., greater 
than 162 takes of the Southcentral Alaska stock of northern sea otters, 
a form of take other than Level A harassment or Level B harassment, or 
take of one or more sea otters through methods not described in the 
IHA), TMC must take the following actions:
    (i) Cease its activities immediately (or reduce activities to the 
minimum level necessary to maintain safety);
    (ii) Report the details of the incident to the FWS within 48 hours; 
and
    (iii) Suspend further activities until the FWS has reviewed the 
circumstances and determined whether additional mitigation measures are 
necessary to avoid further unauthorized taking.
    (3) All operations managers, vehicle operators, and machine 
operators must receive a copy of this IHA and maintain access to it for 
reference at all times during project work. These personnel must 
understand, be fully aware of, and be capable of implementing the 
conditions of the IHA at all times during project work.
    (4) This IHA will apply to activities associated with the specified 
project as described in this document and in TMC's revised request. 
Changes to the specified project without prior authorization may 
invalidate the IHA.
    (5) TMC's revised request is approved and fully incorporated into 
this IHA unless exceptions are specifically noted herein. The request 
includes:
    (i) TMC's original request for an IHA, dated March 1, 2024;
    (ii) A revised application, dated March 18, 2024; and
    (iii) Marine Mammal Mitigation and Monitoring Plan.
    (6) Operators will allow the FWS personnel or the FWS's designated 
representative to visit project worksites to monitor for impacts to sea 
otters and subsistence uses of sea otters at any time throughout 
project activities so long as it is safe to do so. ``Operators'' are 
all personnel operating under TMC's authority, including all 
contractors and subcontractors.

B. Avoidance and Minimization

    (7) Construction activities must be conducted using equipment that 
generates the lowest practicable levels of underwater sound within the 
range of frequencies audible to sea otters.
    (8) During all pile-installation activities, regardless of 
predicted sound levels, a physical interaction shutdown zone of 10 m 
(33 ft) must be enforced. If a sea otter enters the shutdown zone, in-
water activities must be delayed until either the animal has been 
visually observed outside the shutdown zone, or 15 minutes have elapsed 
since the last observation time without redetection of the animal.
    (9) If the impact driver has been idled for more than 30 minutes, 
an initial set of three strikes from the impact driver must be 
delivered at reduced energy, followed by a 1-minute waiting period, 
before full-powered proofing strikes.
    (10) In-water activity must be conducted in daylight. If 
environmental conditions prevent visual detection of sea otters within 
the shutdown zone, in-water activities must be stopped until visibility 
is regained.

C. Mitigation Measures for Vessel Operations

    Vessel operators must take every precaution to avoid harassment of 
sea otters when a vessel is operating near these animals. The applicant 
must carry out the following measures:
    (11) Vessels must remain at least 500 m (0.3 mi) from rafts of sea 
otters unless safety is a factor. Vessels must reduce speed and 
maintain a distance of 100 m (328 ft) from all sea otters unless safety 
is a factor.
    (12) Vessels must not be operated in such a way as to separate 
members of a group of sea otters from other members of the group and 
must avoid alongshore travel in shallow water (<20 m) whenever 
practicable.
    (13) When weather conditions require, such as when visibility 
drops, vessels must adjust speed accordingly to avoid the likelihood of 
injury to sea otters.
    (14) Vessel operators must be provided written guidance for 
avoiding collisions and minimizing disturbances to sea otters. Guidance 
will include all measures identified in this section.

D. Monitoring

    (15) Operators shall work with PSOs to apply mitigation measures 
and shall recognize the authority of PSOs up to and including stopping 
work, except where doing so poses a significant safety risk to 
personnel.
    (16) Duties of the PSOs include watching for and identifying sea 
otters, recording observation details, documenting presence in any 
applicable monitoring zone, identifying and documenting potential 
harassment, and working with operators to implement all appropriate 
mitigation measures.
    (17) A sufficient number of PSOs will be available to meet the 
following criteria: 100 percent monitoring of exclusion zones during 
all daytime periods of underwater noise-generating work; a maximum of 4 
consecutive hours on watch per PSO; a maximum of approximately 12 hours 
on watch per day per PSO.
    (18) All PSOs will complete a training course designed to 
familiarize individuals with monitoring and data collection procedures. 
A field crew leader with prior experience as a sea otter observer will 
supervise the PSO team. Initially, new or inexperienced PSOs will be 
paired with experienced PSOs so that the quality of marine mammal 
observations and data recording is kept consistent. Resumes

[[Page 59765]]

for candidate PSOs will be made available for the FWS to review.
    (19) Observers will be provided with reticule binoculars (7x50 or 
better), big-eye binoculars or spotting scopes (30x), inclinometers, 
and range finders. Field guides, instructional handbooks, maps, and a 
contact list will also be made available.
    (20) Observers will collect data using the following procedures:
    (i) All data will be recorded onto a field form or database.
    (ii) Global positioning system data, sea state, wind force, and 
weather will be collected at the beginning and end of a monitoring 
period, every hour in between, at the change of an observer, and upon 
sightings of sea otters.
    (iii) Observation records of sea otters will include date; time; 
the observer's locations, heading, and speed (if moving); weather; 
visibility; number of animals; group size and composition (adults/
juveniles); and the location of the animals (or distance and direction 
from the observer).
    (iv) Observation records will also include initial behaviors of the 
sea otters, descriptions of project activities and underwater sound 
levels being generated, the position of sea otters relative to 
applicable monitoring and mitigation zones, any mitigation measures 
applied, and any apparent reactions to the project activities before 
and after mitigation.
    (v) For all sea otters in or near a mitigation zone, observers will 
record the distance from the sound source to the sea otter upon initial 
observation, the duration of the encounter, and the distance at last 
observation in order to monitor cumulative sound exposures.
    (vi) Observers will note any instances of animals lingering close 
to or traveling with vessels for prolonged periods of time.
    (21) Monitoring of the shutdown zone must continue for 30 minutes 
following completion of pile installation.

E. Measures To Reduce Impacts to Subsistence Users

    (22) Prior to conducting the work, TMC will take the following 
steps to reduce potential effects on subsistence harvest of sea otters:
    (i) Avoid work in areas of known sea otter subsistence harvest;
    (ii) Discuss the planned activities with subsistence stakeholders 
including Southcentral Alaska villages and traditional councils;
    (iii) Identify and work to resolve concerns of stakeholders 
regarding the project's effects on subsistence hunting of sea otters; 
and
    (iv) If any concerns remain, develop a POC in consultation with the 
FWS and subsistence stakeholders to address these concerns.

F. Reporting Requirements

    (23) The applicant, TMC, must notify the FWS at least 48 hours 
prior to commencement of activities.
    (24) Monthly reports will be submitted to the FWS's Marine Mammal 
Management office (MMM) for all months during which noise-generating 
work takes place. The monthly report will contain and summarize the 
following information: dates, times, weather, and sea conditions 
(including the Beaufort Scale sea state and wind force conditions) when 
sea otters were sighted; the number, location, distance from the sound 
source, and behavior of the sea otters; the associated project 
activities; and a description of the implementation and effectiveness 
of mitigation measures with a discussion of any specific behaviors the 
sea otters exhibited in response to mitigation.
    (25) A final report will be submitted to the FWS's MMM within 90 
days after completion of work or expiration of the IHA. The report will 
include:
    (i) A summary of monitoring efforts (hours of monitoring, 
activities monitored, number of PSOs, and, if requested by the FWS, the 
daily monitoring logs).
    (ii) A description of all project activities, along with any 
additional work yet to be done. Factors influencing visibility and 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog and glare) will be discussed.
    (iii) A description of the factors affecting the presence and 
distribution of sea otters (e.g., weather, sea state, and project 
activities). An estimate will be included of the number of sea otters 
exposed to noise at received levels corresponding to Level A harassment 
or Level B harassment (based on visual observation).
    (iv) A description of changes in sea otter behavior resulting from 
project activities and any specific behaviors of interest.
    (v) A discussion of the mitigation measures implemented during 
project activities and their observed effectiveness for minimizing 
impacts to sea otters. Sea otter observation records will be provided 
to the FWS in the form of electronic database or spreadsheet files.
    (26) Injured, dead, or distressed sea otters that are not 
associated with project activities (e.g., animals known to be from 
outside the project area, previously wounded animals, or carcasses with 
moderate to advanced decomposition or scavenger damage) must be 
reported to the FWS within 24 hours of the discovery to either the 
FWS's MMM Office (1-800-362-5148, business hours); or the Alaska 
SeaLife Center in Seward (1-888-774-7325, 24 hours a day), or both. 
Photographs, video, location information, or any other available 
documentation must be provided to the FWS.
    (27) All reports shall be submitted by email to 
[email protected].
    (28) TMC must notify the FWS upon project completion or end of the 
work season.

Request for Public Comments

    If you wish to comment on this proposed authorization, the 
associated draft environmental assessment, or related documents, you 
may submit your comments by either of the methods described in 
ADDRESSES. Please identify the document(s) to which your comments 
pertain, make your comments as specific as possible, confine them to 
issues pertinent to the proposed authorization, and explain the reason 
for any changes you recommend. Where possible, your comments should 
reference the specific section or paragraph that you are addressing. 
The FWS will consider all comments that are received before the close 
of the comment period (see DATES). The FWS does not anticipate 
extending the public comment period beyond the 30 days required under 
section 101(a)(5)(D)(iii) of the MMPA.
    Comments, including names and street addresses of respondents, will 
become part of the administrative record for this proposal. Before 
including your address, telephone number, email address, or other 
personal identifying information in your comment, be advised that your 
entire comment, including your personal identifying information, may be 
made publicly available at any time. While you can ask us in your 
comments to withhold from public review your personal identifying 
information, we cannot guarantee that we will be able to do so.

Peter Fasbender,
Assistant Regional Director for Fisheries and Ecological Services, 
Alaska Region.
[FR Doc. 2024-16166 Filed 7-22-24; 8:45 am]
BILLING CODE 4333-15-P