[Federal Register Volume 84, Number 132 (Wednesday, July 10, 2019)]
[Notices]
[Pages 32932-32945]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-14667]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[Docket No. FWS-R7-ES-2019-0053; FXES111607MRG01-190-FF07CAMM00]


Marine Mammals; Incidental Take During Specified Activities; 
Proposed Incidental Harassment Authorizations for Northern Sea Otters 
in Southeast Alaska

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of applications and proposed incidental 
harassment authorizations; availability of draft environmental 
assessments; request for comments.

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SUMMARY: We, the U.S. Fish and Wildlife Service, have received two 
requests, one from the City and Borough of Sitka (CBS) and one from 
Duck Point Development II, LLC (DPD), for authorization to take small 
numbers of the southeast Alaska stock of northern sea otters incidental 
to pile driving in Sitka Sound and Port Frederick, Alaska, between 
April 1, 2019, and September 30, 2019. However, due to the time needed 
to process the request, we evaluated the estimated take of northern sea 
otters during project activities between July 22, 2019, and December 
31, 2019. We estimate there may be up to 12 nonlethal, incidental takes 
by harassment of 4 northern sea otters for the CBS project, and up to 
1,380 nonlethal, incidental takes by harassment of 220 northern sea 
otters for the DPD project. In accordance with provisions of the Marine 
Mammal Protection Act of 1972, we request comments on our proposed 
authorizations, which, if finalized, will be for take by Level B 
harassment only. We anticipate no take by injury or death and include 
none in these proposed authorizations.

DATES: Comments on the proposed incidental harassment authorizations 
and draft environmental assessments must be received by August 9, 2019.

ADDRESSES: Document availability: You may view these proposed 
authorizations, the application packages, supporting information, draft 
environmental assessments, and the

[[Page 32933]]

lists of references cited herein at http://www.regulations.gov under 
Docket No. FWS-R7-ES-2019-0053, or these documents may be requested as 
described under FOR FURTHER INFORMATION CONTACT. You may submit 
comments on these proposed authorizations by one of the following 
methods:
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: Docket No. FWS-R7-ES-2019-0053, Division of Policy, Performance, 
and Management Programs, U.S. Fish and Wildlife Service, 5275 Leesburg 
Pike, MS: BPHC, Falls Church, VA 22041-3803.
     Electronic submission: Federal eRulemaking Portal at: 
http://www.regulations.gov. Follow the instructions for submitting 
comments to Docket No. FWS-R7-ES-2019-0053.
    We will post all comments at http://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: Mr. Christopher Putnam, U.S. Fish and 
Wildlife Service, 1011 East Tudor Road, MS 341, Anchorage, Alaska, 
99503, by email at [email protected], or by telephone at 
1-800-362-5148. Persons who use a telecommunications device for the 
deaf (TDD) may call the Federal Relay Service (FRS) at 1-800-877-8339.

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 of 
a species or population stock by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
region during a period of not more than 1 year. Incidental take by 
harassment may be authorized only if statutory and regulatory 
procedures are followed and the U.S. Fish and Wildlife Service 
(hereafter, ``the Service'' or ``we'') makes the following findings: 
(i) Take is of a small number of animals, (ii) take will have a 
negligible impact on the species or stock, and (iii) take will not have 
an unmitigable adverse impact on the availability of the species or 
stock for subsistence uses by coastal-dwelling Alaska Natives.
    The term ``take,'' as defined by the MMPA, means to harass, hunt, 
capture, or kill, or to attempt to harass, hunt, capture, or kill any 
marine mammal (16 U.S.C. 1362(13)). Harassment, as defined by the MMPA, 
means any act of pursuit, torment, or annoyance that (i) has the 
potential to injure a marine mammal or marine mammal stock in the wild 
(the MMPA calls this ``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 calls this ``Level B harassment'').
    The terms ``negligible impact,'' ``small numbers,'' and 
``unmitigable adverse impact'' are defined in the Code of Federal 
Regulations at 50 CFR 18.27, the Service's regulations governing take 
of small numbers of marine mammals incidental to specified activities. 
``Negligible impact'' is defined as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival. Although ``small 
numbers'' is defined in 50 CFR 18.27, we do not rely on that definition 
as it conflates the terms ``small numbers'' and ``negligible impact,'' 
which we recognize as two separate and distinct requirements (see 
Natural Res. Def. Council, Inc. v. Evans, 232 F. Supp. 2d 1003, 1025 
(N.D. Cal. 2003)). In our determination, we evaluate ``small numbers'' 
by analyzing the number of marine mammals likely to be taken in 
relation to the size of the overall stock. ``Unmitigable adverse 
impact'' is defined as an impact resulting from the specified activity 
(1) that is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by (i) causing the 
marine mammals to abandon or avoid hunting areas, (ii) directly 
displacing subsistence users, or (iii) placing physical barriers 
between the marine mammals and the subsistence hunters, and (2) that 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    If the requisite findings are made, we issue an incidental 
harassment authorization (IHA), which sets forth the following: (i) 
Permissible methods of taking; (ii) other means of effecting the least 
practicable impact on marine mammals and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of marine mammals for taking for 
subsistence uses by coastal-dwelling Alaska Natives; and (iii) 
requirements for monitoring and reporting take.

Summary of Requests

City and Borough of Sitka--O'Connell Bridge Lightering Float

    On November 12, 2018, the City and Borough of Sitka, Alaska, 
(hereafter ``CBS'') submitted a request to the Service's Marine Mammals 
Management Office (MMM) for authorization to take by harassment a small 
number of northern sea otters (Enhydra lutris kenyoni, hereafter also 
``sea otters'' or ``otters''). Following requests for additional 
information, CBS submitted an amended application on March 21, 2019, 
and additional information was received on March 25, 2019. The 
applicant expects that take by incidental harassment may occur during 
its planned pile-driving activities at the O'Connell Bridge dock 
facility located in Sitka, Alaska.

Duck Point Development II, LLC--Hoonah Berth II Project

    On January 30, 2019, Duck Point Development II, LLC, (hereafter 
``DPD'') submitted a request to the Service's MMM for authorization to 
take by harassment a small number of sea otters. Following requests for 
additional information, DPD submitted an amended application on March 
21, 2019. The applicant expects that take by incidental harassment may 
occur during their planned pile-driving activities at Cannery Point 
located near Hoonah, Alaska.

Description of Specified Activities and Geographic Area

City and Borough of Sitka--O'Connell Bridge Lightering Float

    The specified activity (the ``project'') consists of CBS's proposed 
repairs to the O'Connell Bridge Lightering Float, specifically the 
removal and replacement of six 16-inch-diameter steel pipe piles. CBS 
will conduct work on 3 days between July 22, 2019, and December 31, 
2019.
    Removal of the extant piles will be accomplished by either dry pull 
or vibratory extraction. Sockets to accommodate the replacement piles 
will be drilled so that the piles may be installed to a greater depth 
than that of the existing piles, allowing for the accommodation of 
larger vessels. The replacement piles will be installed using both 
vibratory and impact methods. Transfer of personnel and equipment 
between shore and the work platform will be done using skiffs 
approximately 7.6-10.7 meters (m) or 25-30 feet (ft) in length with a 
35-50 horsepower (hp)

[[Page 32934]]

outboard engine. Further information and technical specifications can 
be found in CBS's IHA application available at: http://www.regulations.gov, Docket No. FWS-R7-ES-2019-0053.

Duck Point Development II, LLC--Hoonah Berth II Project

    The project at Hoonah consists of two components: (1) The 
installation of a lightering float at the existing dock facility on the 
southwest side of Cannery Point; and (2) the installation of a cruise 
ship berth on the northeast side of Cannery Point. This will involve 
the installation and subsequent removal of up to 62 temporary 30-inch 
piles and installation of 45 permanent piles ranging from 24 to 42 
inches in diameter. Temporary piles will be installed and removed by 
vibratory extraction; permanent piles will be installed using both 
vibratory and impact methods. Additionally, there will be socket and 
anchor drilling to secure piles at depth. Transfer of personnel and 
equipment between shore and the work platform will be done using skiffs 
approximately 7.6-10.7 m (25-30 ft) in length with a 35-50 hp outboard 
engine, and a similar vessel will be used for visual monitoring of 
marine mammals in the waters of Port Frederick and parts of Icy Strait. 
Work will take place over a 75-day period between July 22, 2019, and 
December 31, 2019. Further information and technical specifications can 
be found in DPD's IHA application at: http://www.regulations.gov, 
Docket No. FWS-R7-ES-2019-0053.

Description of Marine Mammals in the Specified Area

    The northern sea otter is currently the only marine mammal under 
the Service's jurisdiction that normally occupies Sitka Sound and Port 
Frederick, Alaska. There are three stocks of northern sea otters in 
Alaska. These are the southeast, southcentral, and southwest stocks. 
Sea otters that occur in Sitka Sound and Port Frederick/Icy Strait 
belong to the southeast Alaska stock. The Service's most recent stock 
assessment report is available at https://www.fws.gov/alaska/fisheries/mmm/stock/Revised_April_2014_Southeast_Alaska_Sea_Otter_SAR.pdf.
    Sea otters may occur anywhere within the specified project area 
other than upland areas. Abundance and densities of the southeast 
Alaska stock of sea otters were estimated from aerial surveys conducted 
by the Service in cooperation with the U.S. Geological Survey (USGS) 
between 1995 and 2012 (Tinker et al., in press). Total abundance in the 
northern region of Southeast Alaska was estimated to be 11,635 sea 
otters, with over half (7,955) of these animals occurring in Glacier 
Bay (Tinker et al., in press). Densities of sea otters in the project 
areas were estimated at 0.842 otters per square km (km\2\) in Sitka 
Sound and 0.368 otters per km\2\ in Port Frederick and Icy Strait 
(Tinker et al., in press).
    Sea otters generally occur in shallow water near the shoreline. 
They are most commonly observed within the 40-m (131-ft depth contour 
(USFWS, 2014), although they can be found in areas with deeper water. 
Depth is generally correlated with distance to shore, and sea otters 
typically remain within 1 to 2 kilometers (km) (0.62 to 1.24 miles 
(mi)) of shore (Riedman and Estes 1990). They tend to remain closer to 
shore during storms, but they may be found farther from shore when seas 
are calm (Lensink 1962; Kenyon 1969).
    Sea otters are non-migratory and generally do not disperse over 
long distances (Garshelis and Garshelis 1984). They usually remain 
within a few kilometers of their established feeding grounds (Kenyon 
1981). Breeding males remain for all or part of the year in a breeding 
territory covering up to 1 km (0.62 mi) of coastline. Adult females 
have 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). Although sea otters generally remain local to an area, 
they are capable of long-distance travel. Otters in Alaska have shown 
daily movement distances greater than 3 km (1.9 mi) at speeds up to 5.5 
km/hour (3.4 mi/hour) (Garshelis and Garshelis 1984).

Potential Effects of the Activities

Exposure of Sea Otters to Noise

    The applicants have requested authorizations for Level B incidental 
harassment of the southeast Alaska stock of northern sea otters. Otters 
in the project area will be exposed to the visual and auditory 
stimulation associated with the presence and operation of pile-driving 
equipment and support vessels. Vessel traffic and human presence on 
docks are common in Sitka Sound and Port Frederick/Icy Strait; however, 
pile-driving operations will create sounds that are unfamiliar to 
otters in these areas. If sea otters are disturbed, it will likely be 
due to the underwater noise associated with pile-driving operations, or 
possibly, the noise in tandem with the sight of equipment and vessels. 
Pile driving and vessel operations may cause disruptions to 
biologically significant sea otter behavioral patterns, thereby 
resulting in incidental take by Level B harassment.

Noise From Pile Driving

    During the course of pile driving, a portion of the kinetic energy 
from the hammer is lost to the water column in the form of sound. 
Levels of underwater sounds produced during pile driving are dependent 
upon the size and composition of the pile, the substrate into which the 
pile is driven, bathymetry, physical and chemical characteristics of 
the surrounding waters, and pile installation method (Illingworth and 
Rodkin 2007, 2014; Denes et al. 2016).
    Both impact and vibratory pile installation produce underwater 
sounds of frequencies predominantly lower than 2.5 kilohertz (kHz), 
with the highest intensity of pressure spectral density at or below 1 
kHz (Denes et al. 2016; Dahl et al. 2015; Illingworth and Rodkin 2007). 
Source levels of underwater sounds produced by impact pile driving tend 
to be higher than for vibratory pile driving; however, both methods of 
installation can generate underwater sound levels capable of causing 
behavioral disturbance or hearing threshold shift in marine mammals. A 
summary of the properties of sounds produced by the proposed activities 
can be found in table 1.
    Whether a specific noise source will affect an otter depends on 
several factors, including the distance between the animal and the 
sound source, the sound intensity, background noise levels, the noise 
frequency, duration, and whether the noise is pulsed or continuous. The 
actual noise level perceived by individual otters will depend on 
distance to the pile-driving site, whether the animal is above or below 
water, atmospheric and environmental conditions, and the operational 
parameters of the piles and pile-driving equipment being used.

[[Page 32935]]



                       Table 1--Summary of Acoustic Source Levels for Proposed Activities
----------------------------------------------------------------------------------------------------------------
                                           Sound  pressure
     Applicant            Activity         levels  (dB re 1           Frequency                References
                                              [micro]Pa)
----------------------------------------------------------------------------------------------------------------
CBS...............  Impact pile driving  181.3 dBPK @10 m     Up to 2.5 kHz...........  Austin et al. 2016;
                                          (168.2 dBSEL @10                               Denes et al. 2016.
                                          m).
CBS...............  Vibratory pile       161 @10 m..........  Up to 2.5 kHz...........  Austin et al. 2016;
                     installation/                                                       Denes et al. 2016.
                     removal.
CBS...............  Socket drilling....  189.8 @1 m.........  Up to 10 kHz............  Denes et al. 2016.
CBS...............  General vessel       145-175 dB rms @1 m  10-1,500 Hz.............  Richardson et al. 1995;
                     operations.                                                         Kipple and Gabriele
                                                                                         2004; Ireland and
                                                                                         Bisson 2016.
CBS...............  Barge operations...  180 dB rms @1 m....  10-1,500 Hz.............  Richardson et al. 1995;
                                                                                         Kipple and Gabriele
                                                                                         2004; Ireland and
                                                                                         Bisson 2016.
DPD...............  Impact pile driving  198.6 dBPK @10 m     Up to 2.5 kHz...........  Austin et al. 2016;
                                          (186.7 dBSEL @10                               Denes et al. 2016.
                                          m).
DPD...............  Vibratory pile       161.9 to 168.2 @10   Up to 2.5 kHz...........  Austin et al. 2016;
                     installation/        m.                                             Denes et al. 2016.
                     removal.
DPD...............  Socket and anchor    189.8 @1 m.........  Up to 10 kHz............  Denes et al. 2016.
                     drilling.
DPD...............  General vessel       145-175 dB rms @1 m  10-1,500 Hz.............  Richardson et al. 1995;
                     operations.                                                         Kipple and Gabriele
                                                                                         2004; Ireland and
                                                                                         Bisson 2016.
DPD...............  Barge operations...  180 dB rms @1 m....  10-1,500 Hz.............  Richardson et al. 1995;
                                                                                         Kipple and Gabriele
                                                                                         2004; Ireland and
                                                                                         Bisson 2016.
----------------------------------------------------------------------------------------------------------------
CBS = City and Borough of Sitka, DPD = Duck Point Development II, LLC for Hoonah Berth II, dBPK = Decibels peak,
  dBSEL = Decibels sound exposure level, dBRMS = Decibels root mean squared.

Noise From Vessels
    Characteristics of sounds produced by vessels are a product of 
several variables pertaining to the specifications of the vessel, 
including the number and type of engines, propeller shape and size, and 
the mechanical condition of these components. Operational status of the 
vessel, such as pushing or towing heavy loads, or using bow thrusters, 
can significantly affect the levels of sounds emitted by the same 
vessel at different times (Richardson et al. 1995; Ireland and Bisson 
2016).
    The proposed vessels are skiffs approximately 7.6-10.7 m (25-30 ft) 
in length with 35-50 hp outboard engines. Recordings of sounds produced 
by similar vessels in Glacier Bay National Park were loudest at 
frequencies between roughly 100 Hertz (Hz) and 5 kHz, with source 
levels ranging from 160-182 Decibels referenced at 1 micro Pascal at 1 
meter (dB re 1 [micro]Pa at 1 m) (Kipple and Gabriele 2004). Acoustic 
properties of sounds expected from vessel operations are shown in table 
1.
Sea Otter Hearing
    Sound frequencies produced by vessels, pile driving, and removal 
equipment will fall within the hearing range of northern sea otters and 
will be audible to animals during the proposed construction activities. 
Controlled sound exposure trials on southern sea otters (E. l. nereis) 
indicate that those otters can hear frequencies between 125 Hz and 38 
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) sounds than terrestrial 
mustelids but similar to that of sea lions. 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 
2012a).
    Exposure to high levels of sound may cause changes in behavior, 
masking of communications, temporary or permanent changes in hearing 
sensitivity, discomfort, and injury. Species-specific criteria for sea 
otters have not been identified for preventing harmful sound exposures. 
Thresholds have been developed for other marine mammals, above which 
exposure is likely to cause behavioral disturbance and injuries 
(Southall et al. 2007, 2019; Finneran and Jenkins 2012; NMFS 2018a). 
Because sea otter hearing abilities and sensitivities have not been 
fully evaluated, we relied on functionally similar hearing information 
from other species to evaluate the potential effects of noise exposure.
    California sea lions (Zalophus californianus) (an otariid pinniped) 
have shown a frequency range of hearing most functionally similar to 
that of southern sea otters (Ghoul and Reichmuth 2014) and provide the 
closest proxy for which data are available. Sea otters and otariid 
pinnipeds share a similar mammalian aural physiology (Echteler et al. 
1994; Solntseva 2007). Both are adapted to amphibious hearing, and both 
use sound in similar ways.
Exposure Thresholds
    Noise exposure criteria have been established by the NMFS for 
identifying underwater noise levels capable of causing Level A 
harassment (injury) of marine mammals, including otariid pinnipeds 
(NMFS 2018a). Sea otter-specific criteria have not been established; 
however, because of the biological similarities between otariid 
pinnipeds and sea otters, we assume that noise criteria developed by 
NMFS for injury for otariid pinnipeds are a suitable proxy for sea 
otters. Those criteria are based on estimated levels of sound exposure 
capable of causing a permanent shift in sensitivity of hearing (e.g., a 
permanent threshold shift (PTS) (NMFS 2018a)). Exposure to moderate 
durations of very loud noise or long-term continuous exposure of 
moderate noise levels may cause the hairs within the inner ear system 
to die or disable the synapses between hair cells and their neurons, 
resulting in PTS.
    NMFS's (2018a) criteria for sound exposure incorporate two metrics 
of exposure: The peak level of instantaneous exposure likely to cause 
PTS, and the effects of cumulative exposure 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. The estimated PTS

[[Page 32936]]

thresholds for otariid pinnipeds are 232 dB peak and 203 dB sound 
exposure level cumulative (SELcum) for impulsive noise, and 219 dB 
SELcum for non-impulsive noise (NMFS 2018a). NMFS criteria for Level A 
harassment represents the best available information for predicting 
injury from exposure to underwater sound among otariid pinnipeds. We 
assume these criteria also represent appropriate exposure limits for 
Level A harassment of sea otters. A recent review of literature 
regarding the effects of noise upon the hearing of marine mammals 
placed sea otters into a functional hearing group called ``other 
carnivores'', which also includes otariid pinnipeds (Southall et al. 
2019), but no new hearing threshold criteria were identified in that 
study.
    NMFS (2018a) criteria do not identify thresholds for avoidance of 
Level B harassment. For pinnipeds, NMFS has adopted a 160-dB threshold 
Level B harassment from exposure to impulse noise and a 120-dB 
threshold for continuous noise (NMFS 1998; HESS 1999; NMFS undated). 
These thresholds were developed from observations of mysticetes 
responding to airgun operations (e.g., Malme et al. 1983a, 1983b; 
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) reviewed the literature and derived TTS 
thresholds for pinnipeds from impulsive sounds based on 212 dB peak and 
171 dB SELcum. The updated review from Southall et al. (2019) gives 
values of 232 dB peak and 203 dB SELCUM for the TTS 
threshold for the ``other carnivore'' group. Kastak et al. (2005) found 
exposures resulting in TTS in pinnipeds ranging from 152 to 174 dB 
(183-206 dB SEL). Kastak et al. (2008) demonstrated persistent TTS, if 
not PTS, after 60 seconds of 184 dB SEL. Kastelein et al. (2012) found 
small but statistically significant TTSs at approximately 170 dB SEL 
(136 dB, 60 min) and 178 dB SEL (148 dB, 15 min). Finneran (2015) 
summarized these and other studies, which NMFS (2018a) has used to 
develop a TTS threshold for otariid pinnipeds of 199 dB 
SELCUM.
    Southall et al. (2007) also assessed behavioral response studies 
and found considerable variability among captive pinnipeds. They 
determined that exposures between approximately 90-140 dB generally do 
not induce strong behavioral responses in pinnipeds in water (Southall 
et al. 2007). Avoidance and other behavioral effects were observed in 
the range between 120-160 dB; however, only one of the observed 
reactions reported in Southall et al. (2007) was sufficiently severe to 
meet behavioral criteria for take by Level B harassment (see 
Characterizing Take by Level B Harassment, below). In the Evidence from 
Sea Otter Studies section below, we review the observed and studied 
behavioral responses of wild sea otters to noise. Behavioral 
observations indicate that a 120-dB threshold is likely to overestimate 
the likelihood of Level B harassment, but these studies do not provide 
definitive support for a particular threshold. Therefore, the work of 
NMFS (2018a, undated), Southall et al. (2007, 2019), and others 
described here represent the best available data and suggest that 
either a 199-dB SELCUM threshold or a 160-dB threshold is 
likely to be the best predictor of Level B harassment.
    In conclusion, a 199-dB SELCUM exposure threshold is 
likely to be more accurate than a 160-dB threshold when the behaviors 
of individual otters can be closely monitored. Given the lack of TTS 
data specific to otters, the 160-dB threshold provides a measure of 
insurance against underestimation of the possible risks to otters, and 
provides greater practicability for application of mitigation and 
monitoring.
    Exposure to impulsive sound levels greater than 160 dB can elicit 
behavioral changes in marine mammals that might be detrimental to 
health and long-term survival where it disrupts normal behavioral 
routines. Thus, using information available for other marine mammals as 
a surrogate, and taking into consideration the best available 
information about sea otters, the Service has determined the received 
sound level under water of 160 dB as a threshold for Level B take by 
disturbance for sea otters for this proposed IHA (based on Ghoul and 
Reichmuth 2012a,b; McShane et al. 1995; Riedman 1983; Richardson et al. 
1995; and others). Exposure to unmitigated in-water noise levels 
between 125 Hz and 38 kHz that are greater than 160 dB will be 
considered by the Service as Level B take for both continuous and 
impulsive sound sources; thresholds for potentially injurious Level A 
take will be 232 dB peak or 203 dB SEL for impulsive sounds and 219 dB 
SEL for continuous sounds (table 2).

Table 2--Summary of Northern Sea Otter Acoustic Thresholds for Underwater Sound in the Frequency Range 125 Hz-38
                                                       kHz
----------------------------------------------------------------------------------------------------------------
                                               Injury (Level A) threshold               Disturbance (Level B)
                                    ------------------------------------------------          threshold
           Marine mammals                                                           ----------------------------
                                          Impulsive \1\         Non-Impulsive \1\                All
----------------------------------------------------------------------------------------------------------------
Sea otters.........................  232 dB peak; 203 dB     219 dB SELCUM.........  160 dB rms.
                                      SELCUM.
----------------------------------------------------------------------------------------------------------------
\1\ Based on NMFS acoustic criteria for otariid pinnipeds (NMFS 2018a).

Evidence From Sea Otter Studies

    The available studies of northern and southern sea otter behavior 
indicate that sea otters are somewhat more resistant to the effects of 
sound than other marine mammals (Riedman 1983, 1984; Ghoul et al. 
2012a, b; Reichmuth and Ghoul 2012). Southern sea otters off the 
California coast showed only mild interest in boats passing within 
hundreds of meters and appeared to have habituated to boat traffic 
(Riedman 1983; Curland 1997). There are no available data regarding the 
reactions of northern sea otters to pile driving. Southern sea otters 
in an area with frequent railroad noise appeared to be relatively 
undisturbed by pile-driving activities, many showing no response and 
generally reacting more strongly to passing vessels than to the sounds 
of pile-driving equipment (ESNERR 2011; ESA 2016). Additionally, many 
of the otters who displayed a reaction behavior during pile driving did 
so while their heads were above the surface of the water, suggesting 
that airborne noise was as important as underwater noise in prompting 
the animals' reactions. When sea otters have displayed behavioral 
disturbance in response to acoustic stimuli, responses were short-
lived, and the otters quickly became habituated and resumed normal 
activity (Davis et al. 1987, 1988; Ghoul et al. 2012b). Sea otters may 
be less sensitive to noise as

[[Page 32937]]

they do not rely on sound to orient themselves, locate prey, or 
communicate underwater.
    Sea otters in Alaska have shown signs of disturbance (escape 
behaviors) in response to the presence and approach of vessels. 
Behaviors included diving or actively swimming away from a boat, 
hauled-out sea otters entering the water, and groups of otters 
dispersing and swimming in multiple different directions (Udevitz et 
al. 1995). Sea otters in Alaska have also been shown to avoid areas 
with heavy boat traffic but return to those same areas during seasons 
with less traffic (Garshelis and Garshelis 1984).
    Disturbance is possible from the applicants' activities. Individual 
sea otters in Sitka Sound and Port Frederick/Icy Strait are likely to 
show a range of responses to noise from the applicants' equipment and 
vessels. Some may abandon the construction areas and return when the 
disturbance has ceased. Based on the observed movement patterns of wild 
otters (i.e., Lensink 1962; Kenyon 1969, 1981; Garshelis and Garshelis 
1984; Riedman and Estes 1990), we expect that some individuals (e.g., 
independent juveniles) will respond to the applicants' proposed 
activities by dispersing to nearby areas of suitable habitat while 
others will not be displaced.
    Some otters will likely show startle responses, change direction of 
travel, or dive. Otters reacting to pile driving or vessels may divert 
time and attention from biologically important behaviors, such as 
feeding. Other effects may be undetectable in observations of behavior, 
especially the physiological effects of chronic noise exposure. Some 
otters in the area of activity may become habituated to noise caused by 
the project due to the existing continual vessel traffic in the area 
and will have little, if any, reaction to the presence of vessels or 
human activity on the barge platforms.

Effects on Habitat

    Habitat areas of significance for otters exist near the project 
areas. Physical and biological features of coastal habitat essential to 
the conservation of northern sea otters include the benthic 
invertebrates (urchins, mussels, clams, etc.) eaten by otters and the 
shallow rocky areas and kelp beds that provide cover from predators. 
The CBS project involves the removal and replacement of piles at an 
extant dock facility, and little to no habitat within Sitka Sound will 
be altered. For the DPD project, the lightering float will be installed 
between two busy commercial docks at Cannery Point. This area already 
experiences frequent vessel traffic, and the addition of the lightering 
float will not result in a substantial increase in vessel traffic to 
the area. Therefore, it is unlikely that sea otter habitat would be 
significantly modified by the addition of the lightering float.
    The northeast side of Cannery Point--the proposed location for the 
second cruise ship berth at Hoonah--is not developed and otters may be 
displaced by the installation of the berth and a subsequent increase in 
vessel traffic. Impacts upon benthic habitat of otters and their prey 
are minimized by the use of a floating dock, which will not require 
dredging or fill. The installation of the berth will increase vessel 
traffic to the northeast side of Cannery Point where otters may become 
habituated to traffic or may be displaced. However, passengers from 
cruise ships are currently being transferred to shore a few at a time 
on board small vessels. The presence of a facility at which passengers 
can walk off a vessel to participate in shore excursions will bring 
about a reduction in the number of small vessel trips between moored 
cruise ships and the shore near Cannery Point.

Mitigation and Monitoring

    If IHAs for the applicants' projects are issued, they must specify 
means for effecting the least practicable impact on northern sea otters 
and their habitat, paying particular attention to habitat areas of 
significance, and on the availability of northern sea otters for taking 
for subsistence uses by coastal-dwelling Alaska Natives.
    In evaluating what mitigation measures are appropriate to ensure 
the least practicable adverse impact on a species or stock and their 
habitat, as well as subsistence uses, we considered the manner in 
which, and the degree to which, the successful implementation of the 
measures are expected to reduce impacts to sea otters, their habitat, 
and their availability for subsistence uses. 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).
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, the applicants have proposed mitigation 
measures including, but not limited to, the following:
     Development of marine mammal monitoring and mitigation 
plans;
     Establishment of shutdown and monitoring zones during 
noise-generating work;
     Visual mitigation monitoring by designated Protected 
Species Observers (PSOs);
     Conducting all work during periods of good visibility;
     Site clearance before start-up;
     Soft-start procedures;
     Shutdown procedures;
     Use of pile caps to reduce noise during impact pile 
driving; and
     Vessel strike avoidance measures.
    These measures are further specified under Proposed Authorizations, 
part B. Avoidance and Minimization.

Estimated Incidental Take

Characterizing Take by Level B Harassment

    An individual sea otter's reaction will depend on its prior 
exposure to vessels and human presence at the project sites, some 
intrinsic motivation or requirement to be in the particular area, its 
physiological status, or other intrinsic factors. The location, timing, 
frequency, intensity, and duration of the encounter are among the 
external factors that will also influence the animal's response.
    Relatively minor reactions such as increased vigilance or a short-
term change in direction of travel are not likely to disrupt 
biologically important behavioral patterns and are not considered take 
by harassment as defined by the MMPA. These types of responses typify 
the most likely reactions of sea otters that will be exposed to the 
applicants' activities. Extreme behavioral reactions capable of causing 
injury are characterized as Level A harassment events, which are 
unlikely to result from the proposed project and will not be 
authorized. Intermediate reactions that disrupt biologically 
significant behaviors of the affected animal meet the criteria for 
Level B harassment under the MMPA. In 2014, the Service identified the 
following sea otter behaviors as indicating possible Level B 
harassment. The following list does not describe all possible 
behaviors, and other situations may indicate 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 (spy hopping) while apparently agitated or while 
swimming away;
     In the case of a pup, repeatedly spy hopping while hiding 
behind and holding onto its mother's head;

[[Page 32938]]

     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 along the shoreline;
     Ceasing mating behaviors;
     Shifting/jostling/agitation in a raft so that the raft 
disperses;
     Sudden diving of an entire raft; and
     Flushing animals off a haulout.

Estimating Exposure Rates

    The Service anticipates that incidental harassment of sea otters 
may occur during the proposed activities in Sitka Sound and Port 
Frederick/Icy Strait. Underwater noise levels from pile driving and 
related activities may cause short-term, nonlethal, but biologically 
significant changes in behavior that the Service considers Level B 
harassment. The number of animals affected will be determined by the 
distribution of animals and their location in proximity to the project 
work.
    Sound exposure criteria provide the best available proxy for 
estimation of exposure. The behavioral response of sea otters to 
shoreline construction and vessel activities is related to the distance 
between the activity and the animals. Underwater sound is generated in 
tandem with other airborne visual, olfactory, or auditory signals from 
the specified activities, and travels much farther. Therefore, 
estimating exposure to underwater sound can be used to estimate 
exposure to all proposed activities.
    No separate exposure evaluation was done for activities that do not 
generate underwater sound. All of the proposed activities that may 
disturb sea otters will occur simultaneously with in-water activities 
that do generate sound. For example, operation of heavy equipment on 
barge platforms will facilitate underwater pile driving. The otters 
affected by the equipment operations are the same as those affected by 
the pile driving. Sound exposure and behavioral disturbances are 
accumulated over a 24-hour period, resulting in estimation of one 
exposure from all in-water sources rather than one each from equipment 
operations and pile-driving noise.

Predicting Behavioral Response Rates

    Although we cannot predict the outcome of each exposure of a sea 
otter to the sounds, equipment, and vessels used for the proposed 
activities, it is possible to consider the most likely reactions. 
Whether an individual animal responds behaviorally to such exposure is 
dependent upon many variables. The health, physiological state, 
reproductive state, and temperament of the individual animals will have 
an effect. Factors such as the activity of the animal, exposure to 
other disturbances, habituation of the animal to similar disturbances, 
and the presence of predators, pups, or other otters will have an 
effect as well. We assumed all animals exposed to underwater sound 
levels that meet acoustic criteria would experience Level B harassment.
Distances to Thresholds
    The total take of sea otters for each of the proposed construction 
projects in Sitka Sound and Port Frederick was estimated by calculating 
the number of otters in the ensonified areas during the full duration 
of the projects. To calculate the areas that will be ensonified during 
each component of the projects, we first estimated the distances that 
underwater sound will travel before attenuating to levels below 
thresholds for take by Level A and Level B harassment. The distances to 
the Level A thresholds were calculated using the NMFS Acoustical 
Guidance Spreadsheets (NMFS 2018b) and their thresholds for otariid 
pinnipeds as a proxy for sea otters. Distances to the 160-dB Level B 
threshold were calculated using a practical spreading transmission loss 
model (15 LogR).
    Model estimates incorporated operational and environmental 
parameters for each activity, and characteristics of the sound produced 
are shown in table 3. Weighting factor adjustments were used for SEL 
calculations based on NMFS Technical Guidance (NMFS 2018a). Operational 
parameters were estimated from the description of activities outlined 
in the applicants' petitions.

                                  Table 3--Assumptions Used in Calculating Distances to Level A and Level B Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Source level                      Source         Pulse
          Activity             Type of source        \1\           WFA \2\        velocity       duration    Repetition rate       Duration per day
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact pile driving (16-inch  Stationary       181.3 dBPK @10   2 kHz........  N/A..........  N/A..........  30 strikes/pile  <=0.1 hrs/day.
 piles).                       impulsive.       m (168.2 dBSEL
                                                @10 m).
Vibratory pile driving (16-   Stationary non-  161 @10 m......  2.5 kHz......  N/A..........  N/A..........  N/A............  1 hr/day.
 inch piles).                  impulsive.
Socket drilling.............  Stationary non-  189.8 @1 m.....  2.5 kHz......  N/A..........  N/A..........  N/A............  6 hrs/day.
                               impulsive.
Crew skiff..................  Mobile non-      175 @1 m.......  1.5 kHz......  1.54 m/s.....  N/A..........  N/A............  <1 hr/day.
                               impulsive.
Barge handling skiff........  Stationary non-  180 @1 m.......  1.5 kHz......  N/A..........  N/A..........  N/A............  3 hrs/day.
                               impulsive.
Impact pile driving (36-inch  Stationary       198.6 dBPK @10   2 kHz........  N/A..........  N/A..........  100 strikes/     400 strikes/day.
 piles).                       impulsive.       m (186.7 dBSEL                                                pile.
                                                @10 m).
Impact pile driving (42-inch  Stationary       198.6 dBPK @10   2 kHz........  N/A..........  N/A..........  135 strikes/     370 strikes/day.
 piles).                       impulsive.       m (186.7 dBSEL                                                pile.
                                                @10 m).
Vibratory pile driving (24-   Stationary non-  161.9 @10 m....  2.5 kHz......  N/A..........  N/A..........  N/A............  0.7 hrs/day.
 inch piles).                  impulsive.
Vibratory pile driving (30-   Stationary non-  161.9 @10 m....  2.5 kHz......  N/A..........  N/A..........  N/A............  2 hrs/day.
 inch temporary piles).        impulsive.
Vibratory pile removal (30-   Stationary non-  161.9 @10 m....  2.5 kHz......  N/A..........  N/A..........  N/A............  1 hr/day.
 inch temporary piles).        impulsive.

[[Page 32939]]

 
Vibratory pile driving (30-   Stationary non-  161.9 @10 m....  2.5 kHz......  N/A..........  N/A..........  N/A............  1 hr/day.
 inch piles).                  impulsive.
Vibratory pile driving (36-   Stationary non-  168.2 @10 m....  2.5 kHz......  N/A..........  N/A..........  N/A............  1 hr/day.
 inch piles).                  impulsive.
Vibratory pile driving (42-   Stationary non-  161.9 @10 m....  2.5 kHz......  N/A..........  N/A..........  N/A............  2 hrs/day.
 inch piles).                  impulsive.
Socket and anchor drilling..  Stationary non-  189.8 @1 m.....  2.5 kHz......  N/A..........  N/A..........  N/A............  4 hrs/day.
                               impulsive.
Crew skiff..................  Mobile non-      175 @1 m.......  1.5 kHz......  1.54 m/s.....  N/A..........  N/A............  <1 hr/day.
                               impulsive.
Monitoring skiff............  Mobile non-      175 @1 m.......  1.5 kHz......  1.54 m/s.....  N/A..........  N/A............  12 hrs/day.
                               impulsive.
Barge handling skiff........  Stationary non-  180 @1 m.......  1.5 kHz......  N/A..........  N/A..........  N/A............  3 hrs/day.
                               impulsive.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Source level is given in dBrms re 1 [micro] Pa, unless otherwise indicated, as measured at the given distance from the source in meters.
\2\ Weighting factor adjustment.

    The distances to the modelled Level A and Level B thresholds are 
shown in table 4. Each estimate represents the radial distance away 
from the sound source within which an otter exposed to the sound of the 
activity is expected to experience take by Level A or Level B 
harassment.

                  Table 4--Calculated Distance in Meters (m) to Level A and Level B Thresholds
----------------------------------------------------------------------------------------------------------------
                                                               Level A--NMFS Otariid                 Level B--
                                                 ------------------------------------------------      USFWS
                                                             Impulsive            Non- impulsive ---------------
           Applicant                Activity     ------------------------------------------------      Both
                                                                                                 ---------------
                                                    232 dB peak     203 dB SEL      219 dB SEL      160 dB rms
----------------------------------------------------------------------------------------------------------------
City and Borough of Sitka.....  Impact pile                  0.0             0.4  ..............           263.0
                                 driving (16-
                                 inch piles).
                                Vibratory pile    ..............  ..............             0.3            11.7
                                 driving/removal
                                 (16-inch piles).
                                Socket drilling.  ..............  ..............             8.0            97.0
                                Crew skiff......  ..............  ..............             0.6            10.0
                                Barge handling    ..............  ..............             1.5            21.5
                                 skiff.
Duck Point Development, LLC     Impact pile                  0.0            37.3  ..............         3,744.0
 for Hoonah.                     driving (36-                0.0            28.7                         3,744.0
                                 inch piles).
                                Impact pile
                                 driving (42-
                                 inch piles).
                                Vibratory pile    ..............  ..............             0.3            13.4
                                 driving (24-
                                 inch piles).
                                Vibratory pile    ..............  ..............             0.5            13.4
                                 driving (30-
                                 inch temporary
                                 piles).
                                Vibratory pile    ..............  ..............             0.3            13.4
                                 removal (30-
                                 inch temporary
                                 piles).
                                Vibratory pile    ..............  ..............             0.3            13.4
                                 driving (30-
                                 inch piles).
                                Vibratory pile    ..............  ..............             0.9            35.2
                                 driving (36-
                                 inch piles).
                                Vibratory pile    ..............  ..............             1.4            35.2
                                 driving (42-
                                 inch piles).
                                Socket and        ..............  ..............             9.7            97.0
                                 anchor drilling.
                                Crew skiff......  ..............  ..............             0.6            10.0
                                Monitoring skiff  ..............  ..............             0.6            10.0
                                Barge handling    ..............  ..............             1.5            21.5
                                 skiff.
----------------------------------------------------------------------------------------------------------------

Estimates of Take
    To calculate the areas that will be ensonified by pile driving, we 
used either half or all of the area of the circle of the radii in table 
4, above, depending on the size of the radius. Pile driving will take 
place close to shore; however, many of the radii are small enough that 
their defined circles will fall entirely, or nearly entirely, in the 
water, especially at higher tides--in these instances, the area was 
calculated as [pi] r\2\. The exceptions are the Level B radii for 
impact installation of the 36- and 42-inch piles at Hoonah; for these 
we used half of the area of the circle, or \1/2\ [pi] r\2\.
    The areas ensonified by crew and monitoring vessel operations were 
estimated by multiplying the vessels' anticipated daily track length by 
twice the 160-dB radius plus [pi] r\2\ to account for the rounded ends 
of the track line. Based on the figures provided in the applicants' 
proposals and discussions with the contractors, it was estimated that 
each trip would be no more than 500 m (1,640 ft); six trips per day are 
expected for the crew vessel at Sitka, and eight trips per day are 
expected for the crew vessel at Hoonah. For the monitoring skiff, the 
track length was estimated by multiplying running time by vessel speed: 
12 hours per day by 20 km per hour or about 10 knots, plus the rounded 
end of the track line as described above. The barge handling

[[Page 32940]]

skiff will be stationary, so the ensonified area is simply the area of 
the circle defined by the 160 dB radius, [pi] r\2\.
    We then took two approaches to estimate the number of otters that 
may be present within the areas that will be ensonified by the various 
sound sources. We used densities of otters based on recent analyses of 
data from aerial and skiff-based surveys conducted by the Service and 
USGS in southeast Alaska. The most recently available estimates of the 
distribution and abundance of northern sea otters in southeast Alaska 
indicate that the density of animals in Sitka Sound is 0.842 otters per 
km\2\; in the Port Frederick area the density is estimated at 0.368 
animals per km\2\ (Tinker et al., in press). To estimate the expected 
numbers of animals exposed to noise levels at or above the Level A and 
Level B thresholds, we multiplied the ensonified areas by the density 
of otters and the number of days for each activity. For the Sitka 
project, this resulted in an estimate of zero exposures of northern sea 
otters to noise levels exceeding Level A thresholds and 0.252 exposures 
of northern sea otters to noise levels exceeding Level B thresholds 
(table 5). For the Hoonah project, the estimates are 0.012 Level A 
takes and 199.888 Level B takes (table 5). The only operations with the 
potential for take by Level A harassment are impact pile driving of 36- 
and 48-inch piles. The application of shutdown measures (see Measures 
to Reduce Impact, below) will eliminate the possibility of otters being 
exposed to sounds in excess of Level A thresholds. No authorization of 
take by Level A harassment is being requested, none is expected, and 
none will be authorized.

   Table 5--Estimate of Total Take for Each Proposed Activity Based on Estimates Derived From Northern Sea Otter Densities in the Project Areas. These
                            Estimates Do Not Account for Avoidance of Take by the Application of Proposed Mitigation Measures
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                     Level A                   Level B
                                                                                                     ---------------------------------------------------
                                                                             Number  of    Duration           Impulsive             Non-
                 Applicant                              Activity               piles        (days)   --------------------------  impulsive  ------------
                                                                                                                               -------------
                                                                                                         232 pk      203 SEL      219 SEL      160 rms
--------------------------------------------------------------------------------------------------------------------------------------------------------
City and Borough of Sitka..................  Impact pile driving (16-inch             6            1        0.000        0.000  ...........        0.183
                                              piles).
                                             Vibratory pile driving (16-              6            1  ...........  ...........        0.000        0.000
                                              inch piles).
                                             Socket drilling..............  ...........            2  ...........  ...........        0.000        0.000
                                             Crew skiff...................  ...........            3  ...........  ...........        0.000        0.067
                                             Barge handling skiff.........  ...........            3  ...........  ...........        0.000        0.002
                                                                           -----------------------------------------------------------------------------
    Total..................................  .............................  ...........            3        0.000        0.000        0.000        0.252
--------------------------------------------------------------------------------------------------------------------------------------------------------
DPD/Hoonah Berth II........................  Impact pile driving (36-inch            16            4        0.000        0.006  ...........       32.411
                                              piles).
                                             Impact pile driving (42-inch             8            4        0.000        0.006  ...........       32.411
                                              piles).
                                             Vibratory pile driving (24-             24          4.5  ...........  ...........        0.000        0.000
                                              inch piles).
                                             Vibratory pile driving (30-             62         10.5  ...........  ...........        0.000        0.002
                                              inch temporary piles).
                                             Vibratory pile removal (30-             62         10.5  ...........  ...........        0.000        0.002
                                              inch temporary piles).
                                             Vibratory pile driving (30-              3          1.5  ...........  ...........        0.000        0.000
                                              inch permanent piles).
                                             Vibratory pile driving (36-             16            8  ...........  ...........        0.000        0.006
                                              inch piles).
                                             Vibratory pile driving (42-              8            4  ...........  ...........        0.000        0.006
                                              inch piles).
                                             Socket drilling/rock           ...........           28  ...........  ...........        0.000        0.304
                                              anchoring.
                                             Crew skiff...................  ...........           75  ...........  ...........        0.000        2.217
                                             Monitoring skiff.............  ...........           75  ...........  ...........        0.000      132.489
                                             Barge handling skiff.........  ...........           75  ...........  ...........        0.000        0.040
                                                                           -----------------------------------------------------------------------------
    Total..................................  .............................  ...........           75        0.000        0.012        0.000      199.888
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In the calculation of otter densities, sightings data from transect 
surveys are averaged over a large area. While densities provide the 
most reliable estimates of animal presence within a relatively large 
subset of the area for which density was calculated, they do not 
account for patchy distribution of animals within relatively small 
areas. For each project area considered here, local knowledge suggests 
that sea otter utilization of some areas of habitat near the 
construction sites is greater than indicated by density data. The 
estimates of take based on density (table 5) almost certainly 
underestimate the number of otters likely to be affected by the 
activities planned for each location.
    Solstice Alaska Consulting, Inc. conducted surveys of the Sitka 
O'Connell Bridge site; the data collected suggest that between one and 
four sea otters can be expected near the project area daily (Solstice 
Alaska Consulting Inc., unpublished data). We therefore assumed that 4 
animals would be present on each of the 3 days of operations.
    The Hoonah Indian Association, based on local knowledge and in 
consultation with Solstice Alaska Consulting Inc., indicated that 
between one and six sea otters would likely be

[[Page 32941]]

near the project area daily. Communications among Service staff 
indicated that group sizes at Cannery Point can be larger--frequently 
10 animals (Michelle Kissling, USFWS, pers. comm.). We assumed that a 
group of 10 otters would be present each day in the immediate project 
vicinity at Hoonah. Additionally, the Hoonah Indian Association 
indicated that larger rafts of otters, up to 60 individuals, are 
sighted regularly near Halibut Island, which lies within the Level B 
zone of acoustical influence for impact pile driving for the DPD 
project. For the purposes of estimating take, we therefore assumed that 
60 individuals would be present at Halibut Island on each day during 
the project.
    With this information in mind, we made a second estimate of take by 
Level B harassment by multiplying the number of otters expected to be 
in the Level B harassment zone by the number of days of operations 
(table 6). For the CBS project, operations are expected to take place 
on 3 days and result in the take of four otters each day. Four otters 
multiplied by 3 days results in 12 takes of otters.
    The total number of days of operations for the DPD project is 75. 
However, the number of potentially affected otters on a given day is 
dependent upon which operations are undertaken. During the 8 days of 
impact pile driving at Hoonah, the area in which noise levels will 
exceed the Level B harassment threshold is likely to contain 70 sea 
otters:--10 animals within the immediate vicinity of Hoonah and 60 
animals near Halibut Island. On the other 67 days of pile-driving 
operations, the Level B harassment zone does not reach Halibut Island, 
and would contain only the 10 animals expected to be present in the 
immediate vicinity of Cannery Point. On all 75 days of operations, the 
monitoring skiff will be operating well outside the areas defined by 
the 160-dB zone for pile-driving operations, and so the density 
approach was applied to estimating take for this larger area. Sea 
otters may be encountered within the 160-dB radius created by the 
skiff's motor (10 m or 33 ft). We estimated a Level B harassment of two 
sea otters per day for the operation of the monitoring skiff based on 
the density approach (above). The total number of Level B exposures for 
the DPD/Hoonah Berth II project is 1,380 (table 6).

  Table 6--Estimate of Total Take for Each Proposed Activity Based on Estimates Derived From Northern Sea Otter
                                        Group Sizes in the Project Areas
----------------------------------------------------------------------------------------------------------------
                                                                                     Number of
                                                                     Duration         Level B     Total  Level B
               Applicant                        Activity              (days)      exposures  per     exposures
                                                                                        day
----------------------------------------------------------------------------------------------------------------
City and Borough of Sitka.............  All.....................               3               4              12
                                                                 -----------------------------------------------
                                          Total                   ..............  ..............              12
Duck Point Development/Hoonah Berth II  Impact pile driving.....               8              70             560
                                        Monitoring skiff........              75               2             150
                                        Vibratory pile driving/               67              10             670
                                         removal, socket
                                         drilling, crew vessel,
                                         barge positioning.
                                                                 -----------------------------------------------
                                          Total                   ..............  ..............           1,380
----------------------------------------------------------------------------------------------------------------

    For the CBS project at O'Connell Bridge, we assumed that the four 
animals present on each day would likely be the same individuals from 
day to day. We therefore estimate that there would be 12 exposures of 4 
northern sea otters to sounds in excess of the threshold for take by 
Level B harassment.
    For the DPD/Hoonah Berth II project, we assumed that the 
composition of the groups at Cannery Point and Halibut Island would 
remain static but that two different individuals would be encountered 
by the monitoring skiff on each day of surveys of the waters of Port 
Frederick and Icy Strait. Thus, the number of individuals affected 
would be 10 + 60 + (2 x 75) = 220 otters.

Critical Assumptions

    We propose to authorize up to 12 takes of 4 sea otters by Level B 
harassment from the CBS project. For the DPD/Hoonah Berth II project, 
we propose to authorize up to 1,380 takes of 220 northern sea otters. 
We made several critical assumptions to conduct this analysis. We 
assumed that take by harassment equated to exposure to noise meeting or 
exceeding the specified criteria. We also assumed all otters exposed to 
these noise levels would exhibit behavioral responses that indicate 
harassment or disturbance. We assumed the response rates are uniform 
throughout the population, though there are likely to be some animals 
that respond more to disturbance and some less. Our estimates also do 
not account for variable responses by age and sex. There is not enough 
information available to develop a correction factor for these 
differences; therefore, a correction factor was not applied. This will 
result in overestimation in take calculations from exposure to 
underwater noise and underestimation of take from all other sources. 
The degree of over- or under-estimation of take is unknown.
    The estimate of behavioral responses do not account for the 
variability of movements of animals in the project area. Our assessment 
assumes that the animals near Sitka, Cannery Point, and Halibut Island 
will remain, i.e., the individual composition of the affected groups of 
sea otters will not change. Conversely, we assume that otters 
encountered in the waters of Port Frederick and Icy Strait will be 
transitory, i.e., different individual animals each day. There is not 
enough information about the movement of sea otters in response to 
specific disturbances to refine these assumptions. While otters do have 
smaller home ranges than other marine mammals, and those in the project 
area are likely to be exposed to sound during multiple days of work, it 
is unlikely that any single otter will continue to respond in the same 
manner. The otter will either leave the area then return after 
activities are complete, or it will habituate to the disturbance. 
However, we have no data to adjust for the likelihood of departure or 
habituation. This situation is likely to result in overestimation of 
take.
    We do not account for an otter's time at the water's surface where 
sound attenuates faster than in deeper water. The average dive time of 
a northern sea otter is only 85 to 149 seconds (Bodkin et al. 2004; 
Wolt et al. 2012). Wolt et al.

[[Page 32942]]

(2012) found Prince William Sound sea otters average 8.6 dives per 
feeding bout, and when multiplied by the average dive time (149 sec), 
the average total time a sea otter spends underwater during a feeding 
bout is about 21 minutes. Bodkin et al. (2007) found the overall 
average activity budget (proportion of 24-hour day) spent foraging and 
diving was 0.48 (11.4 hours per day), and 0.52 nondiving time (12.5 
hours per day). Gelatt et al. (2002) found that the percent time 
foraging ranged from 21 percent for females with very young (less than 
3 weeks of age) dependent pups to 52 percent for females with old 
(greater than or equal to 10 weeks of age) pups. Therefore, although 
exposure to underwater sound during a single dive is limited, 
accumulation of exposure over time is expected. Our assessment will 
cause some overestimation in this regard.
    We also assume that the mitigation measures presented will be 
effective for eliminating take by Level A harassment and reducing take 
by Level B harassment. Given that the largest Level A radius is 
slightly under 40 m (131 ft), it is reasonable to expect that visual 
monitoring and mitigation will be effective in this regard. However, 
additional information is needed to quantify the effectiveness of 
mitigation. The monitoring and reporting in these proposed IHAs will 
help fill this information need in the future, but for this suite of 
proposed activities, no adjustments were made to estimate the number of 
Level B takes that will be avoided by applying effective mitigation 
measures.

Potential Impacts on the Southeast Alaska Sea Otter Stock

    The estimated level of take by Level B harassment is small relative 
to the most recent stock abundance estimates for the southeast Alaska 
stock of northern sea otter, which is 25,712 animals (USFWS 2014). The 
take of animals associated with the CBS project is less than 0.1 
percent of the current population size (4 / 25,712 [ap] 0.0002). For 
the DPD project, the take of 220 animals is about 0.9 percent of the 
southeast Alaska stock (220 / 25,712 [ap] 0.0086).

Potential Impacts on Subsistence Uses

    Sea otter subsistence harvest by Alaska Natives from the villages 
of Sitka and Hoonah occurs year-round in areas relatively near the 
proposed project areas. Between 2013 and 2017, Alaska Native residents 
of Sitka harvested approximately 1,541 sea otters averaging 257 per 
year (although numbers from 2018 are preliminary). Over the same 
period, Alaska Native residents of Hoonah harvested 394 animals, 
averaging 67 per year.
    The applicants' activities will not preclude access to hunting 
areas or interfere in any way with individuals wishing to hunt. Pile 
driving and vessel use may displace otters, resulting in changes to 
availability of otters for subsistence use during the project period. 
Otters may be more vigilant during periods of disturbance, which could 
affect hunting success rates. The applicants have coordinated with the 
Indigenous People's Council for Marine Mammals, the Alaska Sea Otter 
and Steller Sea Lion Commission, the Hoonah Indian Association, and the 
Sitka Tribe of Alaska to identify and avoid potential conflicts. The 
applicants reported that no conflicts with sea otter subsistence 
harvest were identified by these groups.

Findings

    We propose the following findings regarding these actions:

Small Numbers

    For small numbers analyses, the statute and legislative history do 
not expressly require a specific type of numerical analysis, leaving 
the determination of ``small'' to the agency's discretion. In this 
case, we propose a finding that the applicants' projects may result in 
takes from the southeast stock as follows: The take of 4 sea otters for 
CBS and 220 sea otters for DPD. The current estimate of the southeast 
Alaska stock of northern sea otters is 25,712 animals (USFWS 2014). The 
number of animals taken associated with the CBS project represent 0.02 
percent of the stock. For the DPD project, the number of animals taken 
represent 0.86 percent of the stock. Based on these numbers, we propose 
a finding that the applicants' projects will take a small number of 
animals.

Negligible Impact

    We propose a finding that the incidental take by harassment 
resulting from the proposed project 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 would, 
therefore, have no more than a negligible impact on the southeast 
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 potential sources of disturbance 
caused by the project; and the potential responses of animals to this 
disturbance. In addition, we reviewed materials supplied by the 
applicants, other operators in Alaska, our files and datasets, 
published reference materials, and species experts.
    Otters are likely to respond to proposed activities with temporary 
behavioral modification or displacement. These reactions are unlikely 
to have consequences for the health, reproduction, or survival of 
affected animals. The areas in which sound production is expected to 
reach levels capable of causing harm are small and we expect visual 
monitoring to eliminate this risk, so Level A harassment is not 
anticipated and not authorized. 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. Some animals may exhibit more acute 
responses typical of Level B harassment, such as fleeing, ceasing 
feeding, or flushing from a haulout. These responses could have 
significant biological impacts for a few affected individuals, but most 
animals will also tolerate this type of disturbance without lasting 
effects. We do not expect this type of harassment to affect annual 
rates of recruitment or survival or result in adverse effects on the 
species or stock.
    Our proposed finding of negligible impact applies to incidental 
take associated with the proposed activities as mitigated by the 
avoidance and minimization measures identified in the applicants' 
mitigation and monitoring plans. These measures are designed to reduce 
interactions with and impacts to otters. Mitigation, monitoring, and 
reporting procedures are required for the validity of our findings and 
are a necessary component of the IHAs. For these reasons, we propose 
findings that the CBS and DPD projects will have a negligible impact on 
the southeast Alaska stock of sea otters.

Impact on Subsistence

    We propose a finding that the anticipated harassment caused by both 
applicants' activities would not have an unmitigable adverse impact on 
the availability of sea otters for taking for subsistence uses. In 
making this finding, we considered the timing and location of the 
proposed activities and the location of subsistence harvest activities 
in the area of the proposed project. We also considered both 
applicants' consultations with subsistence

[[Page 32943]]

communities and commitment to development of a Plan of Cooperation 
(POC), should any adverse impacts be identified.

Required Determinations

National Environmental Policy Act (NEPA)

    We have prepared draft environmental assessment in accordance with 
the NEPA (42 U.S.C. 4321 et seq.). We have preliminarily concluded that 
approval and issuance of the authorizations for the nonlethal, 
incidental, unintentional take by Level B harassment of small numbers 
of the southeast Alaska stock of northern sea otters in Sitka Sound and 
Port Frederick, during activities conducted by the applicants in 2019, 
would not significantly affect the quality of the human environment, 
and that the preparation of an environmental impact statement for these 
actions is not required by section 102(2) of NEPA or its implementing 
regulations. We are accepting comments on these draft environmental 
assessments as described above in ADDRESSES.

Endangered Species Act (ESA)

    The proposed authorization has no effect on any species listed as 
threatened or endangered under the ESA.

Government-to-Government Coordination

    It is our responsibility to communicate and work directly on a 
Government-to-Government basis with federally recognized Alaska Native 
tribes and 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 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 Secretarial 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 proposed activities on 
federally recognized Alaska Native Tribes and corporations. Through the 
IHA process identified in the MMPA, the applicants have presented a 
communication process, culminating in a POC if needed, with the Native 
organizations and communities most likely to be affected by their work. 
The applicants have engaged these groups in informational meetings.

Proposed Authorization

    The Service proposes to issue an IHA to the CBS for up to 12 
incidental takes by Level B harassment of 4 northern sea otters from 
the southeast Alaska stock. We also propose to issue an IHA to DPD for 
up to 1,380 incidental takes by Level B harassment of 220 sea otters. 
Authorized take will be limited to disruption of behavioral patterns 
that may be caused by pile driving and vessel operations conducted by 
the applicants in Sitka Sound and Port Frederick/Icy Strait, Alaska, 
during the time period of July 22, 2019, through December 31, 2019. 
Take by injury or death to northern sea otters resulting from these 
construction activities and vessel operations is neither anticipated 
nor authorized.
    The final IHA will incorporate the mitigation, monitoring, and 
reporting requirements provided below. The applicants would be 
responsible for following these requirements. These authorizations 
would not allow the intentional taking of sea otters.

A. General Conditions for Issuance of the Proposed IHAs

    1. The taking of sea otters whenever the required conditions, 
mitigation, monitoring, and reporting measures are not fully 
implemented as required by the IHAs will be prohibited. Failure to 
follow measures specified may result in the modification, suspension, 
or revocation of the IHA.
    2. If take exceeds the level or type identified in the proposed 
authorization (e.g., greater than 12 incidents of take of sea otters by 
Level B harassment for CBS; greater than 1,380 incidents of take of sea 
otters by Level B harassment for DPD (including separation of a mother 
from young; injury; or death), the IHA will be invalidated and the 
Service will reevaluate its findings. If project activities cause 
unauthorized take, the applicant 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's MMM within 48 hours; and (iii) suspend 
further activities until the Service has reviewed the circumstances, 
determined whether additional mitigation measures are necessary to 
avoid further unauthorized taking, and notified the applicant that it 
may resume project activities.
    3. All operations managers and vessel operators must receive a copy 
of the 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. The IHA will apply to activities associated with the proposed 
project as described in this document and in the applicants' amended 
applications (Solstice Alaska Consulting, Inc., 2019a, and b). Changes 
to the proposed project without prior authorization may invalidate the 
IHA.
    5. The applicants' IHA applications will be approved and fully 
incorporated into the IHAs, unless exceptions are specifically noted 
herein or in the final IHAs.
    The CBS application includes these items: The applicant's original 
request for an IHA, dated November 12, 2018; the applicant's response 
to a request for additional information from the Service, dated March 
19, 2019; the amended application, dated March 21, 2019; the 
applicant's response to a request for additional information from the 
Service, dated March 25, 2019; and the Marine Mammal Monitoring and 
Mitigation Plan prepared by Solstice Alaska Consulting, Inc. (2019b).
    The DPD application includes the following items: The applicant's 
original request for an IHA, dated January 30, 2019; the applicant's 
response to a request for additional information from the Service, 
dated March 19, 2019; the amended application, dated March 21, 2019; 
and the Marine Mammal Monitoring and Mitigation Plan prepared by 
Solstice Alaska Consulting, Inc. (2019a).
    6. Operators will allow Service personnel or the Service's 
designated representative to visit project work sites to monitor 
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 the applicants' 
authority, including all contractors and subcontractors.

B. Avoidance and Minimization

    1. Shutdown and monitoring zones will be established as shown in 
Table 7.

[[Page 32944]]



                             Table 7--Shutdown and Monitoring Zones by Activity Type
----------------------------------------------------------------------------------------------------------------
                                                                                      Level A         Level B
                                                                                  shutdown  zone    monitoring
                 Applicant                                 Activity                  (radius in    zone  (radius
                                                                                      meters)       in  meters)
----------------------------------------------------------------------------------------------------------------
City and Borough of Sitka..................  Impact pile driving (16-inch piles)              10             265
                                             Vibratory pile driving (16-inch                  10              15
                                              piles).
                                             Socket and anchor drilling.........              15             100
                                             Crew skiff.........................              10             100
                                             Barge handling skiff...............              10              25
Duck Point Development, LLC/Hoonah Berth II  Impact pile driving (36-inch piles)              50           3,745
                                             Impact pile driving (42-inch piles)              50           3,745
                                             Vibratory pile driving (24-inch                  10              25
                                              piles).
                                             Vibratory pile driving (30-inch                  10              25
                                              temporary piles).
                                             Vibratory pile removal (30-inch                  10              25
                                              temporary piles).
                                             Vibratory pile driving (30-inch                  10              25
                                              piles).
                                             Vibratory pile driving (36-inch                  10              50
                                              piles).
                                             Vibratory pile driving (42-inch                  10              50
                                              piles).
                                             Socket and anchor drilling.........              15             100
                                             Crew skiff.........................              10             100
                                             Monitoring skiff...................              10             100
                                             Barge handling skiff...............              10              25
----------------------------------------------------------------------------------------------------------------

    2. Vessels will not approach within 100 m (328 ft) of individual 
sea otters or 500 m (1,640 ft) of groups of 10 or more otters. 
Operators will reduce vessel speed if a sea otter approaches or 
surfaces within 100 m (328 ft) of a vessel.
    3. All vessels must avoid areas of active or anticipated 
subsistence hunting for sea otters as determined through community 
consultations.

C. Monitoring

    1. Trained and qualified PSOs will be placed at positions with good 
vantage of shutdown and monitoring zones for pile-driving activities to 
perform the monitoring of sea otters necessary for initiation of 
adaptive mitigation measures.
    2. A trained and qualified PSO will be placed on the vessel used to 
monitor the Level B harassment zones defined in these IHAs and in any 
IHAs issued by the NMFS to perform the monitoring of sea otters 
necessary for initiation of adaptive mitigation measures.
    3. While on shift, PSOs will have no primary duties other than to 
watch for and report on events related to marine mammals.

D. Measures To Reduce Impacts to Subsistence Users

    Prior to conducting the work, applicants will take the following 
steps to reduce potential effects on subsistence harvest of sea otters: 
(i) Avoid work in areas of known subsistence harvest of sea otters; 
(ii) discuss the planned activities with subsistence stakeholders 
including Sitka Sound and Port Frederick villages, traditional 
councils, and harvest commissions; (iii) identify and work to resolve 
concerns of stakeholders regarding the project's effects on subsistence 
hunting of sea otters; and (iv) if any unresolved or ongoing concerns 
remain, develop a POC in consultation with the Service and subsistence 
stakeholders to address these concerns.

E. Reporting Requirements

    1. The applicants must notify the Service at least 48 hours prior 
to commencement of activities.
    2. Reports will be submitted to the Service's MMM weekly during 
project activities. The reports will summarize project work and 
monitoring efforts.
    3. A final report will be submitted to the Service's MMM within 90 
days after the expiration of the IHAs. It will include a summary of 
monitoring efforts and observations. All project activities will be 
described, along with any additional work yet to be done. Factors 
influencing visibility and detectability of marine mammals (e.g., sea 
state, number of observers, fog, and glare) will be discussed. The 
report will describe changes in sea otter behavior resulting from 
project activities and any specific behaviors of interest. Sea otter 
observation records will be provided in the form of an electronic 
database or spreadsheet files. The report will assess any effects that 
operations may have had on the availability of sea otters for 
subsistence harvest and, if applicable, evaluate the effectiveness of 
the POC for preventing impacts to subsistence users of sea otters.
    4. Injured, dead, or distressed sea otters that are associated with 
project activities must be reported to the Service MMM within 48 hours 
of discovery. Injured, dead, or distressed sea otters that are not 
associated with project activities (e.g., animals found outside the 
project area, previously wounded animals, or carcasses with moderate to 
advanced decomposition, or scavenger damage) do not need to be reported 
to the Service. Photographs, video, location information, or any other 
available documentation shall be provided to the Service.
    5. If behaviors indicative of Level B harassment are observed 
during the course of pile driving or vessel operations, the PSO will 
record the details regarding the behavior(s) and the distance(s) at 
which the animals showed behaviors indicative of harassment. If such 
incidences take place at distances greater than the standoff and 
shutdown radii described above in Avoidance and Minimization, this 
information will be reported to the Service's MMM within 24 hours; the 
Service MMM will evaluate the information and determine whether 
adjustment of the standoff or shutdown distance is appropriate.
    6. All reports shall be submitted by email to 
[email protected].
    7. Applicants must notify the Service upon project completion or 
end of the work season.

References

    A list of the references cited in this notice is available at 
www.regulations.gov in Docket No. FWS-R7-ES-2019-0053.

Request for Public Comments

    If you wish to comment on these proposed IHAs, the associated draft 
environmental assessments, or both, you

[[Page 32945]]

may submit your comments by any of the methods described in ADDRESSES. 
Please identify if you are commenting on the proposed IHAs (and which 
IHA), draft environmental assessments (and which environmental 
assessment), or both (IHAs and environmental assessments), make your 
comments as specific as possible, confine them to issues pertinent to 
the proposed authorization(s), 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).
    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.

    Dated: May 30, 2019.
Gregory E. Siekaniec,
Regional Director, Alaska Region.
[FR Doc. 2019-14667 Filed 7-9-19; 8:45 am]
 BILLING CODE 4333-15-P