[Federal Register Volume 84, Number 53 (Tuesday, March 19, 2019)]
[Proposed Rules]
[Pages 10224-10251]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-05127]



[[Page 10223]]

Vol. 84

Tuesday,

No. 53

March 19, 2019

Part III





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 18





Marine Mammals; Incidental Take During Specified Activities: Cook 
Inlet, Alaska; Proposed Rule

  Federal Register / Vol. 84 , No. 53 / Tuesday, March 19, 2019 / 
Proposed Rules  

[[Page 10224]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 18

[Docket No. FWS-R7-ES-2019-0012; FXES111607MRG01-190-FF07CAMM00]
RIN 1018-BD63


Marine Mammals; Incidental Take During Specified Activities: Cook 
Inlet, Alaska

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule; availability of draft environmental assessment; 
revision of information collection; and request for comments.

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SUMMARY: We, the U.S. Fish and Wildlife Service, in response to a 
request from Hilcorp Alaska, LLC, Harvest Alaska, LLC, and the Alaska 
Gasline Development Corporation, propose to issue regulations 
authorizing the nonlethal, incidental take by harassment of small 
numbers of northern sea otters in State and Federal waters (Alaska and 
the Outer Continental Shelf) within Cook Inlet, Alaska, as well as all 
adjacent rivers, estuaries, and coastal lands. Take may result from oil 
and gas exploration, development, production, and transportation 
activities occurring for a period of 5 years. This proposed rule would 
authorize take by harassment only; no lethal take would be authorized. 
If this rule is finalized, we will issue Letters of Authorization, upon 
request, for specific proposed activities in accordance with the 
regulations. We intend that any final action resulting from this 
proposed rule will be as accurate and as effective as possible. 
Therefore, we request comments on these proposed regulations. We have 
also submitted a request for revision of existing Information 
Collection 1018-0070 to the Office of Management and Budget for 
approval.

DATES: Comments on these proposed incidental take regulations and the 
accompanying draft environmental assessment will be accepted on or 
before April 3, 2019.
    Information Collection Requirements: If you wish to comment on the 
information collection requirements in this proposed rule, please note 
that the Office of Management and Budget (OMB) is required to make a 
decision concerning the collection of information contained in this 
proposed rule between 30 and 60 days after publication of this proposed 
rule in the Federal Register. Therefore, comments should be submitted 
to OMB by April 18, 2019.

ADDRESSES: 
    Document availability: You may view this proposed rule, the 
application package, supporting information, draft environmental 
assessment, and the list of references cited herein at http://www.regulations.gov under Docket No. FWS-R7-ES-2019-0012, or these 
documents may be requested as described under FOR FURTHER INFORMATION 
CONTACT. You may submit comments on the proposed rule by one of the 
following methods:
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: Docket No. FWS-R7-ES-2019-0012, 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-2019-0012.
    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.
    Information collection requirements: Send your comments on the 
requested revision of the information collection request (ICR) to the 
Desk Officer for the Department of the Interior at OMB-OIRA at 202-395-
5806 (fax) or [email protected] (email). Please provide a 
copy of your comments to the Service Information Collection Clearance 
Officer, U.S. Fish and Wildlife Service, MS: BPHC, 5275 Leesburg Pike, 
Falls Church, VA 22041-3803 (mail); or [email protected] (email). 
Please include ``1018-0070'' in the subject line of your comments.

FOR FURTHER INFORMATION CONTACT: Mr. Christopher Putnam, U.S. Fish and 
Wildlife Service, MS 341, 1011 East Tudor Road, Anchorage, Alaska 
99503, by email at [email protected], or by telephone at 907-
786-3844. Persons who use a telecommunications device for the deaf 
(TDD) may call the Federal Relay Service (FRS) at 1-800-877-8339, 24 
hours a day, 7 days a week.
    Questions regarding the Service's request to revise the Information 
Collection control number 1018-0070 may be submitted to the Service 
Information Collection Clearance Officer, U.S. Fish and Wildlife 
Service, MS: BPHC, 5275 Leesburg Pike, Falls Church, VA 22041-3803 
(mail); 703-358-2503 (telephone), or [email protected] (email). Please 
include ``1018-0070'' in the subject line of your email request.

SUPPLEMENTARY INFORMATION: 

Background

    Section 101(a)(5)(A) of the Marine Mammal Protection Act of 1972 
(16 U.S.C. 1361(a)(5)(A)) (MMPA), gives the Secretary of the Interior 
(Secretary) the authority to allow the incidental, but not intentional, 
taking of small numbers of marine mammals in response to requests by 
U.S. citizens engaged in a specified activity in a specified region. 
The Secretary has delegated authority for implementation of the MMPA to 
the U.S. Fish and Wildlife Service (Service). According to the MMPA, 
the Service shall allow this incidental taking for a period of up to 5 
years if we make findings that such taking: (1) Will affect only small 
numbers of individuals of these species or stocks; (2) will have no 
more than a negligible impact on these species or stocks; (3) will not 
have an unmitigable adverse impact on the availability of these species 
or stocks for taking for subsistence use by Alaska Natives; and (4) we 
issue an incidental take regulation (ITR) setting forth: (a) The 
permissible methods of taking, (b) the means of effecting the least 
practicable adverse impact on the species, their habitat, and the 
availability of the species for subsistence uses, and (c) the 
requirements for monitoring and reporting. If final regulations 
allowing such incidental taking are issued, we may then subsequently 
issue a letter of authorization (LOA), upon request, to authorize 
incidental take during the specified activities.
    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,'' ``unmitigable 
adverse impact,'' and ``U.S. citizens,'' among others, are defined in 
title 50 of 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

[[Page 10225]]

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. ``Small 
numbers'' is defined as a portion of a marine mammal species or stock 
whose taking would have a negligible impact on that species or stock. 
However, we do not rely on that definition here, as it conflates the 
terms ``small numbers'' and ``negligible impact,'' which we recognize 
as two separate and distinct requirements. Instead, in our small 
numbers determination, we evaluate whether the number of marine mammals 
likely to be taken is small relative 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. The term ``least practicable adverse 
impact'' is not defined in the MMPA or its enacting regulations. We 
ensure the least practicable adverse impact by requiring mitigation 
measures that are effective in reducing the impacts of the proposed 
activities, but are not so restrictive as to make conducting the 
activities unduly burdensome or impossible to undertake and complete.
    Implementation of the ITR, if finalized, will require information 
collection activities. The Service has requested that the Office of 
Management and Budget revise the existing Information Collection form 
1018-0070, for incidental take of marine mammals in the Beaufort and 
Chukchi Seas, to include oil and gas activities in Cook Inlet.

Summary of Request

    On May 3, 2018, Hilcorp Alaska, LLC (Hilcorp), Harvest Alaska, LLC 
(Harvest), and the Alaska Gasline Development Corporation (AGDC), 
hereinafter referred to as the ``applicant,'' petitioned the Service to 
promulgate regulations pursuant to section 101(a)(5)(A) of the MMPA for 
the nonlethal, unintentional taking of small numbers of northern sea 
otters (Enhydra lutris kenyoni; hereafter ``sea otters'' or ``otters'') 
incidental to oil and gas exploration, development, production, and 
transportation activities in Cook Inlet, Alaska, for a period of 5 
years. On June 28, 2018, the applicant submitted an amended request 
providing additional project details.

Description of the Proposed ITR

    The proposed ITR, if finalized, will not authorize the proposed 
activities. Rather, it will authorize the nonlethal incidental, 
unintentional take of small numbers of sea otters associated with those 
activities based on standards set forth in the MMPA. The proposed ITR 
includes: Permissible amounts and methods of nonlethal taking; measures 
to ensure the least practicable adverse impact on sea otters and their 
habitat; measures to avoid and reduce impacts to subsistence uses; and 
requirements for monitoring and reporting.

Description of the ITR Geographic Area

    The geographic region of the proposed ITR encompasses Cook Inlet 
south of a line from the Susitna River Delta to Point Possession 
(approximately 61[deg]15'54'' N, 150[deg]41'07'' W, to 61[deg]02'19'' 
N, 150[deg]23'48'' W, WGS 1984) and north of a line from Rocky Cove to 
Coal Cove (at approximately 59[deg]25'56'' N, 153[deg]44'25'' W and 
59[deg]23'48'' N, 151[deg]54'28'' W WGS 1984), excluding Ursus Cove, 
Iniskin Bay, Iliamna Bay, and Tuxedni Bay (see Proposed Regulation 
Promulgation, Sec.  18.131 Specified geographic region where this 
subpart applies). The proposed ITR area includes all Alaska State 
waters and Outer Continental Shelf (OCS) Federal waters within this 
area as well as all adjacent rivers, estuaries, and coastal lands where 
sea otters may occur, unless explicitly excluded.
    The geographical extent of the proposed Cook Inlet ITR region is 
approximately 1.1 million hectares (ha) (2.7 million acres (ac)). For 
descriptive purposes, the specified area is organized into two marine 
areas within Cook Inlet: Lower Cook Inlet (south of the Forelands to 
Homer) and middle Cook Inlet (north of the Forelands to the Susitna 
River and Point Possession).

Description of Specified Activities

    The specified activities include work related to oil and gas 
exploration, development, production, transport, and the 
decommissioning of existing facilities conducted by the applicant 
within a 5-year period. Hilcorp and Harvest jointly plan to conduct the 
following activities: Two-dimensional (2D) and three-dimensional (3D) 
seismic surveys in lower Cook Inlet; production drilling from, routine 
operation of, and maintenance of existing oil and gas facilities in 
middle Cook Inlet; geophysical and geohazard surveys in both regions; 
drilling of two to four exploration wells in OCS waters of lower Cook 
Inlet and one to three wells in middle Cook Inlet; construction of a 
dock facility in Chinitna Bay; and decommissioning of an existing 
facility at the Drift River Terminal in middle Cook Inlet. The 
following support activities will be conducted: Pipe and pile driving; 
vertical seismic profiling; and use of a water jet, hydraulic grinder, 
and submersible saw for pipeline and platform maintenance. AGDC plans 
to install a natural gas pipeline from the west side of middle Cook 
Inlet to the east side of lower Cook Inlet and to construct processing 
and loading facilities on either side. Support activities for AGDC will 
include pile driving, dredging, geophysical surveys, trenching, fill 
placement, and anchor handling. Hilcorp, Harvest, and AGDC will use 
vessels and aircraft to support the activities. Detailed descriptions 
of the proposed work are provided in the applicant's petition for 
incidental take regulations for oil and gas activities in Cook Inlet 
(June 28, 2018), the stakeholder engagement plan (April 2018), and the 
marine mammal monitoring and mitigation plan (May 2018). These 
documents can be obtained from the locations described above in 
ADDRESSES. Table 1 summarizes the planned activities.

                                             Table 1--Summary of Planned Activities Included in ITR Petition
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                                                                                                                                     Total anticipated
  Project component name & location      Geographic region          Year(s) planned                   Seasonal timing              duration (2019-2024)
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Anchor Point two-dimensional (2D)     Lower Cook Inlet,       2021 or 2022...............  April-October........................  30 days.
 seismic survey.                       Anchor Point to
                                       Kasilof.

[[Page 10226]]

 
Outer Continental Shelf (OCS) three-  Lower Cook Inlet OCS..  2019.......................  April-June...........................  90 days.
 dimensional (3D) seismic survey.
OCS geohazard survey................  Lower Cook Inlet OCS..  2019 or 2020...............  Fall 2019 or spring 2020.............  30 days.
OCS exploratory wells...............  Lower Cook Inlet OCS..  2020-2022..................  April-October........................  40-60 days per well 2-
                                                                                                                                   4 wells per year.
Iniskin Peninsula exploration and     Lower Cook Inlet, west  2019-2020..................  April-October........................  180 days.
 development.                          side.
Platform & pipeline maintenance.....  Middle Cook Inlet.....  2019-2024..................  April-October........................  180 days.
North Cook Inlet Unit subsea well     Middle Cook Inlet.....  2020.......................  May..................................  14 days.
 geohazard survey.
North Cook Inlet Unit well            Middle Cook Inlet.....  2020.......................  May-June.............................  90 days.
 abandonment activity.
Trading Bay area geohazard survey...  Middle Cook Inlet.....  2020.......................  May..................................  30 days.
Trading Bay area exploratory wells..  Middle Cook Inlet.....  2020.......................  May-October..........................  120-150 days.
Drift River terminal decommissioning  Lower Cook Inlet, west  2023.......................  April-October........................  120 days.
                                       side.
Product loading facility pile         Middle Cook Inlet.....  2021-2023..................  April-October........................  162 days.
 driving.
Material offloading facilities        Middle Cook Inlet.....  2021-2022..................  April-October........................  360 days.
 dredging.
Material offloading facilities pile   Middle Cook Inlet.....  2021-2022..................  April-October........................  146.5 days.
 driving.
Trenching, pipelay, burial..........  Middle Cook Inlet.....  2023-2024..................  April-October........................  360 days.
Pipelay anchor handling.............  Middle Cook Inlet.....  2023-2024..................  April-October........................  18.75 days.
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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 Cook Inlet, Alaska. 
Sea otters in Alaska are composed of three stocks. Those in Cook Inlet 
belong to either the southwest Alaska stock or the southcentral Alaska 
stock, depending on whether they occur west or east of the center of 
Cook Inlet, respectively. A third stock occurs in southeast Alaska.
    The southwest stock of the northern sea otter is the southwest 
distinct population segment (DPS), which was listed as threatened under 
the Endangered Species Act of 1973 (ESA; 16 U.S.C. 1531, et seq.) on 
August 9, 2005 (70 FR 46366). On October 8, 2009 (74 FR 51988), the 
Service finalized designation of 15,164 square kilometers (km\2\) (or 
5,855 square miles (mi\2\)) of critical habitat for the sea otter in 
southwest Alaska. Critical habitat occurs in nearshore marine waters 
ranging from the mean high tide line seaward for a distance of 100 
meters (m), or to a water depth of 20 m. Detailed information about the 
biology and conservation status of the listed DPS can be found at 
https://www.fws.gov/alaska/fisheries/mmm/seaotters/otters.htm. Stock 
assessment reports for each of the three stocks are available at 
https://www.fws.gov/alaska/fisheries/mmm/stock/stock.htm.
    Sea otters may occur anywhere within the specified project area, 
other than upland areas, but are not usually found north of about 
60[deg]23'30'' N. The number of sea otters in Cook Inlet was estimated 
from an aerial survey conducted by the Service in cooperation with the 
U.S. Geological Survey (USGS) in May 2017 (Garlich-Miller et al. 2018). 
The sea otter survey was conducted in all areas of Cook Inlet south of 
approximately 60[deg]16'30'' N within the 40-m (131-feet (ft)) depth 
contour, including Kachemak Bay in southeastern Cook Inlet and Kamishak 
Bay in southwestern Cook Inlet. This survey was designed to estimate 
abundance in Cook Inlet while accounting for the variable densities and 
observability of sea otters in the region. Total abundance was 
estimated to be 19,889 sea otters (standard error = 2,988). Within the 
project area, the highest densities of sea otters were found in the 
outer Kamishak Bay area, with 3.5 otters per km\2\, followed by the 
eastern shore of Cook Inlet with 1.7 otters per km\2\.
    Sea otters generally occur in shallow water near the shoreline. 
They are most commonly observed within the 40-m (131-ft) depth contour 
(USFWS 2014a,b), 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) or 0.62 to 1.24 miles 
(mi) of shore (Riedman and Estes 1990). They tend to remain closer to 
shore during storms, but they venture farther out during good weather 
and calm seas (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; Tinker and Estes 1996).
    Although sea otters generally remain local to an area, they may 
shift home ranges seasonally, and 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 per hour (3.4 mi per hour) (Garshelis 
and Garshelis 1984). In eastern Cook Inlet, large numbers of sea otters 
have been observed riding the incoming tide northward and returning on 
the outgoing tide, especially in August. They are presumably feeding 
along the eastern shoreline of Cook Inlet during the slack tides when 
the weather is good and remaining in Kachemak Bay during periods of 
less favorable weather (Gill et al. 2009; BlueCrest 2013). In western 
Cook Inlet, otters appear to move in and out of Kamishak Bay in 
response to seasonal changes in the presence of sea ice (Larned 2006).

Potential Effects of the Activities

Effects of Noise

    The operations outlined in the Description of Specified Activities 
and described in the applicant's petition have the potential to result 
in take of sea otters by harassment from acoustic

[[Page 10227]]

disturbance. Potential effects are likely to depend on the distance of 
the otter from the sound source and the level of sound received by the 
otter. Project components most likely to cause acoustic disturbance are 
shown in Table 2. Temporary disturbance or localized displacement 
reactions are the most likely to occur. With implementation of the 
proposed mitigation and monitoring measures described in Sec.  18.137 
Mitigation, Sec.  18.138 Monitoring, and Sec.  18.139 Reporting 
requirements, no lethal take is anticipated, and take by harassment 
(Level A and Level B) is expected to be minimized to the greatest 
extent practicable.

  Table 2--Project Components Proposed by Hilcorp Alaska, LLC, Harvest
 Alaska, LLC, and the Alaska Gasline Development Corporation Capable of
   Causing Incidental Take by Harassment of Northern Sea Otters Due to
                     Acoustic Exposure in Cook Inlet
------------------------------------------------------------------------
   Project component name &
           location                    Anticipated noise sources
------------------------------------------------------------------------
Anchor Point two-dimensional   Marine: 1 source vessel with airgun, 1
 (2D) seismic survey.           node vessel; Onshore/Intertidal: Shot
                                holes, tracked vehicles, helicopters.
Outer Continental Shelf (OCS)  2 source vessels with airguns, 2 support
 three-dimensional (3D)         vessels, 1 mitigation vessel
 seismic survey.                (potentially).
OCS geohazard survey.........  1 vessel with echosounders and/or
                                subbottom profilers.
OCS exploratory wells........  1 jack-up rig, drive pipe installation, 2-
                                3 tugs for towing rig, support vessels,
                                helicopters.
Iniskin Peninsula exploration  Construction of causeway, dredging,
 and development.               vessels.
Platform & pipeline            Vessels, water jets, hydraulic grinders,
 maintenance.                   helicopters, and/or sub-bottom
                                profilers.
North Cook Inlet Unit subsea   1 vessel with echosounders and/or
 well geohazard survey.         subbottom profilers.
North Cook Inlet Unit well     1 jack-up rig, tugs towing rig, support
 abandonment activity.          vessel, helicopters.
Trading Bay area geohazard     1 vessel with echosounders and/or
 survey.                        subbottom profilers.
Trading Bay area exploratory   1 jack-up rig, drive pipe installation,
 wells.                         tugs for towing rig, support vessels,
                                helicopters.
Drift River terminal           Vessels.
 decommissioning.
------------------------------------------------------------------------

Noise Levels
    Whether a specific noise source will affect a sea otter depends on 
several factors, including the distance between the animal and the 
sound source, the sound intensity, background noise levels, the noise 
frequency, the noise duration, and whether the noise is pulsed or 
continuous. The actual noise level perceived by individual sea otters 
will depend on distance to the source, whether the animal is above or 
below water, atmospheric and environmental conditions, as well as 
aspects of the noise emitted.
    Noise levels herein are given in decibels referenced to 1 [micro]Pa 
(dB re: 1 [mu]Pa) for underwater sound. All dB levels are 
dBRMS unless otherwise noted; dBRMS refers to the 
root-mean-squared dB level, the square root of the average of the 
squared sound pressure level (SPL) typically measured over 1 second. 
Other important metrics include the sound exposure level (SEL; 
represented as dB re: 1 [mu]Pa\2\-s), which represents the total energy 
contained within a pulse and considers both intensity and duration of 
exposure, and the peak sound pressure (also referred to as the zero-to-
peak sound pressure or 0-p). Peak sound pressure is the maximum 
instantaneous sound pressure measurable in the water at a specified 
distance from the source and is represented in the same units as the 
RMS sound pressure. See Richardson et al. (1995), G[ouml]tz et al. 
(2009), Hopp et al. (2012), Navy (2014), or similar resources for 
descriptions of acoustical terms and measurement units in the context 
of ecological impact assessment. A summary of the sounds produced by 
the various components of the proposed activities is provided in Tables 
3 and 4.

                       Table 3--Summary of Acoustic Source Levels for Proposed Activities
----------------------------------------------------------------------------------------------------------------
                                                        Sound pressure
            Applicant                  Activity         levels (dB re 1        Frequency           Reference
                                                            [mu]Pa)
----------------------------------------------------------------------------------------------------------------
Hilcorp/Harvest Alaska, AGDC....  General vessel      145-175 dB rms at   10-1,500 Hz.......  Richardson et al.
                                   operations.         1 m.                                    1995; Blackwell
                                                                                               and Greene 2003;
                                                                                               Ireland and
                                                                                               Bisson 2016.
Hilcorp/Harvest Alaska, AGDC....  General aircraft    100-124 dB rms at   <500 Hz...........  Richardson et al.
                                   operations.         1 m.                                    1995.
Hilcorp/Harvest Alaska..........  2D seismic survey   217 dB peak at 100  <300 Hz...........  Austin and Warner
                                   (2,400 cui          m; 185 dB SEL at                        2012; 81 FR 47240
                                   airgun).            100 m; 197 dB rms                       (July 20, 2016).
                                                       at 100 m.
Hilcorp/Harvest Alaska..........  3D seismic survey   217 dB peak at 100  <300 Hz...........  Austin and Warner
                                   (2,400 cui          m; 185 dB SEL at                        2012; 81 FR 47240
                                   airgun).            100 m; 197 dB rms                       (July 20, 2016).
                                                       at 100 m.
Hilcorp/Harvest Alaska..........  Geohazard surveys.  210-220 dB rms at   Echosounders &      Manufacturer
                                                       1 m.                side scan sonar:    specifications.
                                                                           >200 kHz. High-
                                                                           resolution sub-
                                                                           bottom profiler:
                                                                           2-24 kHz. Low-
                                                                           resolution sub-
                                                                           bottom profiler:
                                                                           1-4 kHz.
Hilcorp/Harvest Alaska..........  Exploratory         137 dB rms at 1 m.  <200 Hz...........  Marine Acoustics
                                   drilling rig.                                               Inc. 2011.

[[Page 10228]]

 
Hilcorp/Harvest Alaska..........  Tugs under load     191 dB rms at 1 m.  <500 Hz...........  LGL/JASCO/
                                   towing rig.                                                 Greeneridge 2014.
Hilcorp/Harvest Alaska..........  Drive pipe          190 dB rms at 55 m  <500 Hz...........  Illingworth &
                                   installation.                                               Rodkin 2014.
Hilcorp/Harvest Alaska..........  Vertical seismic    227 dB rms at 1 m.  <500 Hz...........  Illingworth &
                                   profiling.                                                  Rodkin 2014.
Hilcorp/Harvest Alaska..........  Sub-bottom          212 dB rms at 1 m.  1-24 kHz..........  Manufacturer
                                   profiling.                                                  specifications.
Hilcorp/Harvest Alaska..........  Rock laying for     136-141 dB rms at   <500 Hz...........  Nedwell and
                                   Iniskin Peninsula   12-19 m.                                Edwards 2004; URS
                                   causeway.                                                   2007.
Hilcorp/Harvest Alaska..........  Vibratory sheet     175 dB peak at 10   <100-2,500 Hz.....  Illingworth &
                                   pile driving for    m; 160 dB SEL at                        Rodkin 2007.
                                   Iniskin Peninsula   10 m; 160 dB rms
                                   causeway.           at 10 m.
Hilcorp/Harvest Alaska..........  Offshore            97-111 dB rms at    <500 Hz...........  Blackwell and
                                   production          0.3-19 km.                              Greene 2003.
                                   platforms.
Hilcorp/Harvest Alaska..........  Water jet.........  176 dB rms at 1 m.  500 Hz-2 kHz......  Austin 2017.
Hilcorp/Harvest Alaska..........  Hydraulic grinder.  159 dB at 1 m.....  <1 kHz............  Stanley 2014.
Hilcorp/Harvest Alaska..........  Pingers...........  192 dB rms at 1 m.  4-14 kHz..........  Manufacturer
                                                                                               specifications.
AGDC............................  Dredging:           107-142.6 dB rms    <2.5 kHz,           Dickerson et al.
                                   Including           at 10 m.            broadband.          2001, URS 2007.
                                   Clamshell dredge,
                                   Winching in/out,
                                   Dumping into
                                   barge, Empty
                                   barge at
                                   placement site.
AGDC............................  Underwater          145 dB @10 m......  <2.5 kHz,           Greene et al.
                                   trenching with                          broadband.          2008.
                                   backhoe in
                                   shallow water.
AGDC............................  Anchor handling...  188 dB............  <2.5 kHz,           LGL/JASCO/
                                                                           broadband.          Greeneridge 2014.
----------------------------------------------------------------------------------------------------------------


      Table 4--Summary of Acoustical Sources of Pile-Driving Activities for AGDC From Illingworth & Rodkin
                                                     [2007]
----------------------------------------------------------------------------------------------------------------
                                                  Sound pressure level (dB re
 Representative pile type and                              1 [mu]Pa)
             size                 Hammer type   ------------------------------     Project pile type and size
                                                   Peak       RMS       SEL
----------------------------------------------------------------------------------------------------------------
24-inch AZ sheet pile........  Impact..........      205       190       180   Sheet pile.
24-inch AZ sheet pile........  Vibratory.......      175       160       160   Sheet pile.
24-inch steel pipe pile......  Impact..........      207       194       178   18- and 24-inch piles.
60-inch steel shell pile.....  Impact..........      210       195       185   48- and 60-inch piles.
72-inch steel pipe piles.....  Vibratory.......      183       170       170   All size piles
----------------------------------------------------------------------------------------------------------------

Sea Otter Hearing
    Sound frequencies produced by the applicant's survey and 
construction activities will fall within the hearing range of sea 
otters and therefore will be audible to animals. Controlled sound 
exposure trials on southern sea otters (E. l. nereis) indicate that 
otters can hear frequencies between 125 hertz (Hz) and 38 kilohertz 
(kHz) with best sensitivity between 1.2 and 27 kHz (Ghoul and Reichmuth 
2014). Aerial and underwater audiograms for a captive adult male 
southern sea otter in the presence of ambient noise suggest the sea 
otter's hearing was less sensitive to high-frequency (greater than 22 
kHz) and low-frequency (less than 2 kHz) sounds than terrestrial 
mustelids but similar to that of a sea lion. 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 changes in hearing sensitivity, 
discomfort, and physical or auditory injury. Species-specific criteria 
for preventing harmful exposures to sound have not been identified for 
sea otters. Thresholds have been developed for other marine mammals, 
above which exposure is likely to cause behavioral disturbance and 
injuries (Southall et al. 2007; Finneran and Jenkins 2012; NMFS 2018a). 
Because sea otter hearing abilities and sensitivities have not been 
fully evaluated, we relied on the closest related proxy, California sea 
lions (Zalophus californianus), to evaluate the potential effects of 
noise exposure.
    The California sea lion, an otariid pinniped, has a frequency range 
of hearing most similar to that of the southern sea otter (Ghoul and 
Reichmuth 2014) and provides the closest related proxy for which data 
are available. Sea otters and pinnipeds share a common mammalian aural 
physiology (Echteler et al. 1994; Solntseva 2007). Both are adapted to 
amphibious hearing, and both use sound in the same way (primarily for 
communication rather than feeding).
Exposure Criteria
    Noise exposure criteria have been established by the National 
Marine Fisheries Service (NMFS) for identifying underwater noise levels 
capable of causing Level A harassment (injury) of

[[Page 10229]]

marine mammals, including otariid pinnipeds (NMFS 2018a). Sea otter-
specific criteria have not been determined; however, because of their 
biological similarities, we assume that noise criteria developed by 
NMFS for injury for otariid pinnipeds will be a suitable surrogate for 
sea otter impacts as well. 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)). PTS 
occurs when noise exposure causes hairs within the inner ear system to 
die. This can occur due to moderate durations of very loud noise level 
exposure, or long-term continuous exposure of moderate noise levels.
    NMFS's (2018a) criteria for sound exposure incorporate two metrics 
of exposure: The peak level of instantaneous exposure likely to cause 
PTS, and the cumulative exposure level during a 24-hour period 
(SELcum). 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. Studies were summarized by Finneran (2015). For 
pinnipeds, PTS is predicted to occur at 232 dB peak or 203 dB SELcum 
for impulsive sound, or 219 dB SELcum for non-impulsive (continuous) 
sound.
    NMFS criteria for Level A represents the best available information 
for predicting injury from exposure to underwater sound among 
pinnipeds, and in the absence of data specific to otters, we assume 
these criteria also represent appropriate exposure limits for Level A 
take of sea otters.
    NMFS (2018a) criteria do not identify thresholds for avoidance of 
Level B take. For pinnipeds, NMFS has adopted a 160-dB threshold for 
Level B take 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 mysticete (baleen) whales 
responding to airgun operations (e.g., Malme et al. 1983a, 1983b; 
Richardson et al. 1986, 1995) and from equating Level B take with noise 
levels capable of causing TTS in lab settings.
    We have evaluated these thresholds and determined that the Level B 
threshold of 120 dB for non-impulsive noise is not applicable to sea 
otters. The 120-dB threshold is based on studies conducted by Malme et 
al. in the 1980s, during which gray whales were exposed to experimental 
playbacks of industrial noise. Based on the behavioral responses of 
gray whales to the playback of drillship noise during a study at St. 
Lawrence Island, Alaska, Malme et al. (1988) concluded that ``exposure 
to levels of 120 dB or more would probably cause avoidance of the area 
by more than one-half of the gray whales.'' Sea otters do not usually 
occur at St. Lawrence Island, Alaska, but similar playback studies 
conducted off the coast of California (Malme 1983a, 1984) included a 
southern sea otter monitoring component (Riedman 1983, 1984). The 1983 
and 1984 studies detected probabilities of avoidance in gray whales 
comparable to those reported in Malme et al. (1988), but there was no 
evidence of disturbance reactions or avoidance in southern sea otters.
    The applicable Level B thresholds mays also depend on the levels of 
background noise present and the frequencies generated. NMFS 
acknowledges that the 120-dB threshold may not be applicable if 
background noise levels are high (NMFS undated), which is the case in 
Cook Inlet, where ambient levels can often exceed 120 dB (Blackwell and 
Greene 2003).
    Thresholds developed for one species may not be appropriate for 
another due to differences in their frequency sensitivities. Continuous 
sound sources associated with the proposed activities include vibratory 
pile driving, vessel activities, use of a hydraulic grinder or water 
jet, dredging, trenching, and anchor handling. These are expected to 
produce low-frequency broadband noise. For example, vibratory pile 
driving will generate sound with frequencies that are predominantly 
lower than 2 kHz, and with the greatest pressure spectral densities at 
frequencies below 1 kHz (Dahl et al. 2015). Sea otters are capable of 
hearing down to 125 Hz, but have relatively poor hearing sensitivity at 
frequencies below 2 kHz (Ghoul and Reichmuth 2014). As a result, much 
of the noise generated by vibratory pile driving and other broadband 
noise is expected to be inaudible or marginally audible to sea otters. 
During a project that occurred in Elkhorn Slough, California, sound 
levels ranging from approximately 135 to 165 dB during vibratory pile 
driving elicited no clear pattern of disturbance or avoidance among 
southern sea otters in areas exposed to these levels of underwater 
sound (ESNERR 2011). In contrast, gray whales are in the group of 
marine mammals believed to be most sensitive to low frequency sounds, 
with an estimated audible frequency range of approximately 10 Hz to 30 
kHz (Finneran 2016). Given the different range of frequencies to which 
sea otters and gray whales are sensitive, the NMFS 120-dB threshold 
based on gray whale behavior is not useful for predicting sea otter 
behavioral responses to low frequency sound.
    The NMFS Level B thresholds do not account for different behaviors 
among taxa. Harbor porpoise, beaked whales, and mysticete whales appear 
significantly more sensitive to noise exposure than other marine 
mammals (e.g., Richardson et al. 1999. Tyack et al. 2011; Southall et 
al. 2007). Although no specific thresholds have been developed for sea 
otters, several alternative behavioral response thresholds for have 
been developed for pinnipeds.
    Southall et al. (2007) assessed behavioral response studies, found 
considerable variability among pinnipeds, and determined that exposures 
between approximately 90 to 140 dB generally do not appear to induce 
strong behavioral responses in pinnipeds in water, but behavioral 
effects, including avoidance, become more likely in the range between 
120 to 160 dB, and most marine mammals showed some, albeit variable, 
responses to sound between 140 to 180 dB. Wood et al. (2012) later 
adapted the approach identified in Southall et al. (2007) to develop a 
probabilistic scale for marine mammal taxa at which 10 percent, 50 
percent, and 90 percent of individuals exposed are assumed to produce a 
behavioral response. For many marine mammals, including pinnipeds, 
these response rates were set at sound pressure levels of 140, 160, and 
180 dB respectively.
    Thresholds based on TTS have been used as a proxy for Level B 
harassment (i.e., 70 FR 1871, January 11, 2005; 71 FR 3260, January 20, 
2006; and 73 FR 41318, July 18, 2008). Southall et al. (2007) derived 
TTS thresholds for pinnipeds based on 212 dB peak and 171-dB SELcum. 
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 a persistent TTS, if not a 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 others studies, which 
NMFS (2018a) has used to develop TTS threshold for pinnipeds of 199 dB 
SELcum.
    Based on the lack of a disturbance response or any other reaction 
by sea otters to the 1980s playback studies and the absence of a clear 
pattern of disturbance or avoidance behaviors attributable to 
underwater sound levels up to about 160 dB resulting from

[[Page 10230]]

vibratory pile driving and other sources of similar low-frequency 
broadband noise, we assume 120 is not an appropriate behavioral 
response threshold for sea otters exposed to continuous underwater 
noise. We assume, based on the work of NMFS (2018a), Southall et al. 
(2007), and others described here, that either a 160-dB threshold or a 
199-dB SELcum threshold is likely to be the best predictor of Level B 
take of sea otters for continuous noise exposure, using southern sea 
otters and pinnipeds as a proxy, and based on the best available data.
    We compared a 199-dB SELcum threshold for TTS from NMFS (2018a) 
with a 160-dB behavioral response threshold (NMFS undated) to determine 
the most appropriate criteria for identifying Level B take from the 
proposed activities. We first evaluated the probability of reaching TTS 
at 199 dB SELcum given the projects' predicted sound levels using 
calculations in user spreadsheets developed by NMFS (2018b; available 
at http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm). We used the 
same assumptions presented by Hilcorp to estimate sound production for 
the proposed 3D seismic surveys. The source levels were estimated at 
217 dB peak, 185 dB SEL, and 197 dB rms at a distance of 100 m. A sound 
source verification (SSV) conducted for similar seismic work in Cook 
Inlet using a 2,400-cui source array indicated a 160-dB zone extended 
7.33 km (4.5 mi) from the source (Austin and Warner 2013; 81 FR 47240, 
July 20, 2016). We assumed the maximum sound pressure level of 217.97 
dB at 1 m, the default 1-kHz frequency weighting adjustment for 
seismic, and a transmission loss coefficient of 15 for shallow water. 
The model output predicts that pinnipeds within 133 m (436 ft) of the 
sound source could experience TTS within 60 seconds. Those remaining 
within 882 m (0.54 mi) of the sound source for 17 minutes could 
experience TTS, as could those within 1.2 km (0.75 mi) for 28 minutes, 
1.7 km (1.1 mi) for 43 minutes, and those remaining within 2.3 km (1.4 
mi) for 72 minutes or longer.
    For Hilcorp's 3D seismic work, a 160-dB threshold predicts an otter 
would experience Level B take at 7.3 km (4.5 mi) from the source 
regardless of duration of exposure. A 199-dB SELcum threshold predicts 
sea otters at 7.3 km (4.5 mi) from the source would experience TTS 
after 6.7 hours of exposure. For an otter within 7.3 km (4.5 mi) of a 
sound source, if duration of exposure is less than 6.7 hours, the 160-
dB threshold will overestimate exposure compared to the 199-dB SELcum 
threshold. Beyond 7.3 km (4.5 mi), the 160-dB threshold will 
underestimate take for otters exposed to noise for periods longer than 
6.7 hours. The normal work period for Hilcorp's 3D seismic will be 2.5-
hour intervals based on the slack tide periods. This suggests that the 
160-dB threshold overestimates otters exposed to a single interval of 
work. However, multiple intervals can be conducted in a day, and if 
both the work and the otters were to remain stationary, otters could be 
exposed for a longer overall duration, causing the 160-dB threshold to 
underestimate take.
    In reality, neither the otters, nor the seismic vessels are 
stationary. Sea otters can swim at average speeds of 5.5 km/h (3.4 mi/
hr) (Garshelis and Garshelis 1984) and maximum speeds up to 9 km/h (5.6 
mi/hr) (UMMZ 2007). At those rates of travel, a sea otter could easily 
depart an ensonification zone prior to cumulative TTS exposure. For 
instance, an otter would experience cumulative TTS after remaining 882 
m (0.54 mi) from a sound source for 17 minutes; alternately, in that 
time, the otter could swim 1.6 km (1 mi) away at a normal pace. If all 
otters did this, a 199-dB SELcum threshold for TTS would overestimate 
take. However, an otter may not be willing to travel beyond the 
boundaries of its normal range. Annual home range sizes of adult sea 
otters are relatively small, with males ranging from 10.5-28.5 km\2\ 
(4-11 mi\2\) and adult females from a few to 62 km\2\ (24 mi\2\); 
juveniles may move greater distances between resting and foraging areas 
(Lensink 1962; Kenyon 1969; Garshelis and Garshelis 1984; Ralls et al. 
1988; Jameson 1989; Riedman and Estes 1990; Tinker and Estes 1996). 
Territorial adult males usually remain within a few kilometers of their 
established feeding grounds (Kenyon 1981). Based on these patterns, 
adult females and subadults are expected to be able to effectively 
avoid TTS due to cumulative exposure from up to the full four-interval 
set of seismic surveys in a 24-hour period, whereas territorial males 
might not. For the territorial males, a 160-dB threshold could 
underestimate take.
    In conclusion, a 199-dB SELcum exposure threshold is likely to be 
more accurate than a 160-dB single level threshold when the behaviors 
of individual otters can be closely monitored. However, a 160-dB 
threshold will generate similar estimates of take from Hilcorp's 3D 
seismic surveys and will overestimate take for quieter sound sources. 
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 set the received sound 
level under water of 160 dB as a threshold for Level B take by 
disturbance for sea otters for this proposed ITR (based on Ghoul and 
Reichmuth 2012a,b; McShane et al. 1995; NOAA 2005; Riedman 1983; 
Richardson et al. 1995, and others). Exposure to unmitigated in-water 
noise levels between 125 Hz and 32 kHz that are greater than 160 dB 
will be considered by the Service as Level B take; 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 5).

Table 5--Summary of Northern Sea Otter Acoustic Thresholds for Underwater Sound in the Frequency Range 125 Hz-32
                                                       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.
                                    XXXXX.
----------------------------------------------------------------------------------------------------------------
\1\ Based on NMFS acoustic criteria for otariid pinnipeds (NMFS 2018a).


[[Page 10231]]

Noise-Generating Activities
    The components of the proposed activities that have the greatest 
likelihood of exposing sea otters to underwater noise capable of 
causing Level A or Level B take include geophysical surveys, pile 
driving, drilling activities, and anchor handling associated with 
pipeline construction. Vessel and aircraft operations also have the 
ability to expose otters to sound and human activities that may cause 
disturbance.
    Geophysical Surveys--Airgun arrays used in seismic surveys to 
locate potential hydrocarbon-bearing geologic formations typically 
produce most noise energy in the 10- to 120-Hertz (Hz) range, with some 
energy extending to 1,000 Hz (Richardson et al. 1995). There is no 
empirical evidence that exposure to pulses of airgun sound is likely to 
cause serious injury or death in any marine mammal, even with large 
arrays of airguns (Southall et al. 2007). However, with source levels 
of up to 260 dB, the potential of seismic airgun arrays to acoustically 
injure marine mammals at close proximity must be considered.
    In addition to seismic surveys for hydrocarbon-bearing formations, 
geophysical surveys are conducted to produce imagery of sea-floor 
surfaces and substrates on a finer spatial scale. These images aid in 
the selection of sites for structures such as docks or submerged 
pipelines and the identification of obstacles or hazards within the 
substrate that may interfere with exploratory drilling. Sounds produced 
by the instruments used for these surveys vary in terms of frequency 
bands, source levels, repetition rates, and beam widths. Peak-to-peak 
operating frequencies range from roughly 300 Hz to several hundred kHz 
and source levels ranging from 170 to 240 dB (Crocker and Fratantonio 
2016).
    Pipe/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 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.
    Drilling Operations--For drilling operations, two project 
components have the potential to disturb sea otters: Installing the 
drive pipe at each well prior to drilling; and vertical seismic 
profiling (VSP) operations that may occur at the completion of each 
well drilling. The types of underwater sounds generated by these 
activities are discussed in ``Pile Driving'' and ``Geophysical 
Surveys,'' respectively.
    Lattice-legged jack-up drill rigs are relatively quiet because the 
lattice legs limit transfer of noise generated from the drilling table 
to the water (Richardson et al. 1995, Spence et al. 2007). Further, the 
drilling platform and other noise-generating equipment is located above 
the ocean surface so there is very little surface contact with the 
water compared to drill ships and semi-submersible drill rigs. Hydro-
acoustic measurements of the Spartan 151 resulted in a source level of 
137 dB (Marine Acoustics, Inc. 2011). The survey results showed that 
this noise was largely associated with the diesel engines used as power 
generators. Generators used on the Endeavour, another lattice-legged 
jack-up rig operating in Cook Inlet, are mounted on pedestals 
specifically to reduce noise transfer through the infrastructure, and 
they are enclosed in an insulated engine room. The results from a sound 
source verification done by Illingworth and Rodkin (2014) indicated 
that noise generated from drilling and generators were below ambient 
noise, 128 dB at distances of 30 to 70 m. Thus, neither drilling itself 
nor the running of pumps and generators on the drill rig is expected to 
produce underwater noise levels that will affect sea otters.
    Aircraft Overflights--Richardson et al. (1995) presented analyses 
of recordings of sounds produced by a Bell 212 helicopter. The 
estimated source levels for two of the flights were 149 and 151 dB re 1 
[mu]Pa-m, and underwater received levels were 109 dB when the aircraft 
flew at an altitude of 152 m (500 ft) and 107 dB at a flight altitude 
of 305 m (1,000 ft). Received sound levels in air at the water surface 
would be 81 and 75 dB re 20 [mu]Pa for flights at 152 and 305 m (500 
and 1,000 ft), respectively.
    Rig Towing and Anchor Handling--The 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 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). Two components of the proposed activities, towing of 
Hilcorp's drilling rig and the manipulation of anchors for the laying 
of the AGDC pipeline, will involve vessel operations that are likely to 
be substantially louder than normal transit.
    Data from recent exploratory drilling activities in the Chukchi and 
Beaufort seas indicate that anchor handling can intermittently produce 
sounds likely greater than 190 dB; the source level of the anchor-
handling vessel was estimated to be 188 dB (LGL/JASCO/Greeneridge 
2014). The same study reported measurements of two configurations of 
tugs towing drilling rigs, the average of which was 190.5 dB.
Airborne Sounds
    The NMFS (2018a) guidance neither addresses thresholds for 
preventing injury or disturbance from airborne noise, nor provides 
thresholds for avoidance of Level B take. However, a review of 
literature by Southall et al. (2007) suggested thresholds for PTS and 
TTS for sea lions exposed to non-pulsed airborne noise of 172.5 and 159 
dB re (20 [mu]Pa)\2\-s SEL. Behavioral responses to overflights are 
addressed in Responses to Activities.
    Conveyance of underwater noise into the air is of little concern 
since the effects of pressure release and interference at the water's 
surface scatter and reflect sound (similar to a Lloyd's mirror) which 
reduces underwater noise transmission into the air. For activities that 
create both in-air and underwater sounds, such as pile driving, we will 
estimate take based on parameters for underwater noise transmission. 
Because sound energy travels more efficiently through water than 
through air, this estimation will also account for exposures to animals 
at the surface.
    Aircraft are the most significant source of airborne sounds. 
Proposed flights are to be conducted at an altitude of 305 m (1,000 ft) 
except during takeoff and landing. At the surface of the water, the 
received sound level from a helicopter flown at this altitude is 
roughly 75 dB re 20 [mu]Pa (see ``Noise-Generating Activities''), and 
so threshold shift is extremely unlikely.
    Loud screams are used to communicate between pups and

[[Page 10232]]

mothers at the surface (McShane et al. 1995), but sea otters do not 
appear to communicate vocally under water, and they do not use sound to 
detect prey. Although masking of these crucial airborne calls is 
possible, the duration of sound from aircraft will be brief and 
therefore unlikely to result in separation of females from pups.

Effects on Habitat and Prey

    Habitat areas of significance for sea otters exist in the project 
area. Sea otter critical habitat was designated under the ESA (74 FR 
51988, October 8, 2009). In Cook Inlet, critical habitat occurs along 
the western shoreline south of approximately Redoubt Point. It extends 
from mean high tide line out to 100 m (328.1 ft) from shore or to the 
20-m (65.6-ft) depth contour. Physical and biological features of 
critical habitat essential to the conservation of 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. Other important habitat in the applicant's project area 
includes outer Kamishak Bay between Augustine Island and Iniskin Bay 
within the 40-m (131-ft) depth contour where high densities of otters 
have been detected.
    The applicant's proposed activities include drilling, dredging, 
trenching, pile driving, and dock construction. These activities would 
change the physical characteristics of localized areas of habitat. 
Construction would result in seafloor disturbance and temporary 
increases in water column turbidity. Docks can increase seafloor 
shading, which affects the amount of light penetration on the seafloor. 
Water quality in may be affected by drilling-related discharges within 
limits permitted by the State of Alaska.
    Sampling efforts at borrow and disposal areas before and after 
dredging activity have produced mixed results in terms of whether 
dredging causes significant changes to the productivity and diversity 
of infaunal benthic and epibenthic invertebrate communities (Fraser et 
al., 2017; Angonesi et al. 2006). The areas where dredging activities 
are proposed include a materials loading facility at Nikiski and along 
the planned AGDC pipeline route between Nikiski and Beluga; the 
proposed disposal area is just west of Nikiski. This is beyond the 
northern limit of sea otter distribution in Cook Inlet, so effects of 
dredging upon invertebrate communities would not affect availability of 
prey to sea otters.
    In addition to the disturbances outlined above to sea otters or 
their designated critical habitat, survey and construction activities 
could affect sea otter habitat in the form of impacts to prey species. 
The primary prey species for sea otters are sea urchins, abalone, 
clams, mussels, crabs, and squid (Tinker and Estes 1999). When 
preferential prey are scarce, otters will also eat kelp, crabs, clams, 
turban snails, octopuses, barnacles, sea stars, scallops, rock oysters, 
fat innkeeper worms, and chitons (Riedman and Estes 1990).
    Limited research has been conducted on the effects of noise on 
invertebrates (Normandeau Associates, Inc. 2012). Christian et al. 
(2003) concluded that there were no obvious effects from seismic 
signals on crab behavior and no significant effects on the health of 
adult crabs. Pearson et al. (1994) had previously found no effects of 
seismic signals upon crab larvae for exposures as close as 1 m (3.3 ft) 
from the array, or for mean sound pressure as high as 231 dB. Pearson 
et al. (1994) did not observe any statistically significant effects on 
Dungeness crab (Cancer magister) larvae shot as close as 1 m from a 
231-dB source. Further, Christian et al. (2004) did not find any 
behavioral or significant health impacts to snow crabs (Chionoecetes 
opilio) exposed to seismic noise. The only effect noted was a reduction 
in the speed of egg development after exposure to noise levels (221 dB 
at 2 m), far higher than what bottom-dwelling crabs could be exposed to 
by seismic guns. Invertebrates such as mussels, clams, and crabs do not 
have auditory systems or swim bladders that could be affected by sound 
pressure. Squid and other cephalopod species have complex statocysts 
(Nixon and Young 2003) that resemble the otolith organs of fish that 
may allow them to detect sounds (Budelmann 1992).
    Some species of invertebrates have shown temporary behavioral 
changes in the presence of increased sound levels. Fewtrell and 
McCauley (2012) reported increases in alarm behaviors in wild-caught 
captive reef squid (Sepioteuthis australis) exposed to seismic airguns 
at noise levels between 156-161 dB. Additionally, captive crustaceans 
have changed behaviors when exposed to simulated sounds consistent with 
those emitted during seismic exploration and pile-driving activities 
(Tidau and Briffa 2016).
    In general, there is little knowledge regarding hearing in marine 
invertebrates or how invertebrates are affected by high noise levels 
(Hawkins and Popper 2012). A review of literature pertaining to effects 
of seismic surveys on fish and invertebrates (Carroll et al. 2016) 
noted that there is a wide disparity between results obtained in field 
and laboratory settings. Some of the reviewed studies indicate the 
potential for noise-induced physiological and behavioral changes in a 
number of invertebrates. However, changes were observed only when 
animals were housed in enclosed tanks and many were exposed to 
prolonged bouts of continuous, pure tones. We would not expect similar 
results in open marine conditions. Given the short-term duration of 
sounds produced by each component of the proposed work, it is unlikely 
that noises generated by survey and construction activities will have 
any lasting effect on sea otter prey.

Potential Impacts From an Oil Spill or Unpermitted Discharge

    Sea otters could be affected by accidentally spilled diesel fuel 
from a vessel associated with proposed activities or from a spill or 
leak from a pipeline or well. An oil spill or unpermitted discharge is 
an illegal act, and ITRs do not authorize take of sea otters caused by 
illegal or unpermitted activities. Typical spills that may result from 
the proposed activities are relatively small in scale and are not 
likely to affect otters. A large spill could affect large numbers of 
otters, but these events are rare.
    Information on oil spills throughout the range of the listed sea 
otter from 2006 to 2010 indicates that an average of four spills of 
crude oil occurred each year in the marine environment (ADEC 2014). 
Crude oil spills ranged in size from less than 4 to 760 liters (L) or 1 
to 200 gallons (gal), with a mean size of about 41.8 L (11 gal). Spills 
of non-crude oil averaged 62 per year, ranging in size from less than 4 
to 24,320 L (1 to 6,400 gal). The majority of the non-crude oil spills 
were small, with a mean size of about 380 L (100 gal) and a median size 
of 4 L (1 gal). These events will have only localized impacts to 
habitat and are unlikely to affect sea otters.
    Effects of a larger spill would depend on the size and location of 
a spill and meteorological conditions at the time. Spilled fuel would 
rapidly be spread by waves, currents, the prevailing winds. Lighter, 
volatile components of the fuel would evaporate to the atmosphere 
almost completely in a few days. Rougher seas, high wind speeds, and 
high temperatures also tend to increase the rate of evaporation and the 
proportion of fuel lost by this process (Scholz et al. 1999). Heavier 
components of fuel may drift, wash ashore, or settle into the water 
column and the seabed.
    If a large oil spill were to occur, the most likely impact upon sea 
otters

[[Page 10233]]

would be mortality due to exposure to and ingestion of spilled oil. 
Contamination of sea otter habitat, their invertebrate prey, and prey 
habitat would most likely result in a range of impacts ranging from 
sublethal to lethal, depending on a wide variety of factors.
    Sea otters are critically dependent upon their fur for 
thermoregulation, and oiling severely reduces fur thermoregulatory 
performance. Thermal conductance (an index of insulative quality) of 
marine mammal fur was significantly decreased after oiling, with sea 
otter pup fur being the most affected (Kooyman et al. 1976). A live 
otter would experience thermal stress, including decreased body 
temperature and significantly increased metabolic rate, as well as 
increased energy expenditure through additional grooming attempts 
(Kooyman et al. 1976; Costa and Kooyman, 1982, 1984; Engelhardt 1983). 
Sea otters may also ingest oil through grooming of oiled fur and 
through ingestion of contaminated prey. Sea otters have exhibited 
hemorrhagic gastrointestinal lesions (Baker et al. 1981), lung, liver, 
and kidney damage, DNA damage, and altered blood chemistry (Lipscomb 
1996; Bickham 1998) after oil ingestion.
    Spills may cause direct and indirect effects on critical habitat 
elements for sea otters, particularly kelp forests. For example, the 
rocky shoreline recovery after the Exxon Valdez oil spill took a decade 
or more (Peterson 2003). The initial loss of the rockweed Fucus 
gardneri triggered a community cascade, including blooms of ephemeral 
green algae caused by loss of Fucus on rocks, followed by loss of 
grazing and predatory gastropods. Fucus recovery was constrained; 
without canopy cover, Fucus recruits were subject to desiccation. Even 
after apparent recovery of Fucus, previously oiled shores exhibited 
more rockweed mortality caused by the senescence of the single-aged 
stand (Peterson 2003). These studies and others such as those after the 
Torrey Canyon oil spill in the United Kingdom (Peterson 2003) point out 
the importance of indirect interactions to the continuity of rocky 
intertidal communities and the lengthy recovery time after severe 
oiling. All of these effects may result in population-level impacts to 
sea otters, as demonstrated by the very large Exxon Valdez oil spill 
(Albers 2003), with a reduction in otter survival rates still evident 9 
years post-spill (Monson 2000).
    Oil and gas operators in Cook Inlet are required to prepare spill 
prevention and response plans to minimize the risk of a spill and 
reduce impacts, should one occur. These efforts help ensure that spills 
and unpermitted discharges of contaminants are unlikely. We do not 
anticipate effects to sea otters as a result of oil spills from this 
activity, and spills are not discussed further in this document.

Collisions

    Vessel collisions with marine mammals can result in death or 
serious injury. Wounds resulting from ship strike may include massive 
trauma, hemorrhaging, broken bones, or propeller lacerations (Knowlton 
and Kraus 2001). An animal at the surface may be struck directly by a 
vessel, a surfacing animal may hit the bottom of a vessel, or an animal 
just below the surface may be cut by a vessel's propeller. Mortality 
associated with boat strike has been identified from recovery of 
carcasses with lacerations indicative of propeller injuries (e.g., Wild 
and Ames 1974; Morejohn et al. 1975). From 1998 to 2001, boat strike 
was identified as the cause of death for 5 of 105 southern sea otter 
mortalities (Kreuder et al. 2003). From 2006 through 2010, evidence 
indicates that 11 southern sea otters were likely struck by boats (USGS 
and California Department of Fish and Game, unpublished data cited in 
77 FR 59211-59220, September 26, 2012). From January 2003 to May 2013, 
researchers recovered 35 southern sea otters with trauma consistent 
with impact from a boat hull or propeller. These data suggest a rate of 
boat-strike mortality in California of 2.6 otters per year, or about 
0.1 percent of the population size.
    Boat strike has been documented as a cause of death across all 
three stocks of northern sea otters in Alaska. Since 2002, the Service 
has undertaken a health and disease study of sea otters in Alaska in 
which the Service conducts necropsies on sea otter carcasses to 
determine cause of death, disease incidence, and status of general 
health parameters. Of 1,433 necropsies conducted during 24 years, boat 
strike or blunt trauma was identified as a definitive or presumptive 
cause of death in 64 cases (4 percent) (USFWS unpublished data). It has 
been determined in most of these cases that, while trauma was the 
ultimate cause of death, there was a contributing factor, such as 
disease or biotoxin exposure, which incapacitated the animal and made 
it more vulnerable to boat strike (USFWS 2014).
    In Alaska, the annual rate of mortality from boat strike was 
similar to that reported for California: 2.7 otters per year (USFWS 
unpublished data). However, these otters belong to much larger and more 
dispersed populations where carcass recovery is lower. Instances of 
vessel collision are likely to be underreported, and the probability of 
collision is unknown.
    Likelihood of vessel strikes involving sea otters appears to be 
primarily related to vessel speed. Most collision reports have come 
from small, fast-moving vessels (NMFS 2003). The severity of injuries 
to marine mammals during a boat strike also depends on vessel speed, 
with the probability of death or serious injury increasing as vessel 
speed increases (Laist et al. 2001; Vanderlaan and Taggart 2007). 
Because sea otters spend a considerable portion of their time at the 
surface of the water, they are typically visually aware of approaching 
boats and are able to move away if a vessel is not traveling too 
quickly.
    The probability of a sea otter/vessel collision involving the 
proposed activities in Cook Inlet is very low for three reasons: First, 
most of the work will occur in lower-density regions of Cook Inlet; 
second, the project work will involve slow-moving, noisy vessels that 
sea otters will easily avoid; and third, the proposed activities will 
constitute only a small fraction of the total level of vessel traffic 
in the region. The high level of traffic in Cook Inlet increases the 
likelihood that otters in the project area are accustomed to avoiding 
vessels and activities similar to the activities proposed.
    The AGDC pipeline work and work by Hilcorp and Harvest on 
maintenance of existing facilities will be conducted in middle Cook 
Inlet, in areas that are outside of the normal range of sea otters. The 
unusual occurrence of otters in middle Cook Inlet makes vessel 
collisions extremely unlikely. Hilcorp and Harvest will conduct their 
3D seismic work in offshore areas of lower Cook Inlet where otter 
densities are also low. They will conduct 2D seismic work along the 
eastern shoreline of lower Cook Inlet where densities are higher, but 
vessel speeds during the proposed activities will be slow. Hilcorp's 
seismic vessels would travel at approximately 4 knots (kn) or 7.4 km/hr 
while towing seismic survey gear and a maximum of 4.5 kn (8.3 km/hr) 
while conducting geophysical surveys. Vessel speed during rig towing 
will generally be less than 5 kn. AGDC's pipeline construction 
operations will proceed at similar slow speeds. Anchor handling will 
occur at about 3 kn. For comparison, freighters in Cook Inlet travel at 
20 to 24 kn (Eley 2006), and small recreational vessels may travel at 
40 kn.
    The applicant's support vessels and vessels in transit will travel 
at faster speeds; for example, Hilcorp's

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maintenance activities will require the use of dive vessels, typically 
ranging up to 21 m (70 ft) in length and capable of approximately 7 
knots (13 km/hr). The risk of collision is thus reduced, but not 
eliminated, by the predominance of slow-moving vessel work in areas of 
low density.
    Commercial and recreational vessels are much more common in both 
space and time than are geophysical survey activities, drilling support 
operations, and pipeline work. Based on U.S. Coast Guard records and 
other local sources of information compiled by Eley (2006), 704 large 
vessels, other than fuel barges in domestic trade, called at Cook Inlet 
ports from January 1, 2005, through July 15, 2006. Almost two-thirds 
(65 percent) of the calls were made by container vessels, cargo, or 
ferries. Twenty-nine percent (29 percent) of the vessel traffic was gas 
or liquid tankships calling primarily at Nikiski. Bulk carriers and 
general cargo ships represented 6 percent. Tugs and fishing and 
passenger vessels combined represented 2 percent of the Cook Inlet 
vessel traffic. Tugs made approximately 150 fuel barge transits a year, 
assisted in docking and undocking ships in Nikiski and Anchorage, and 
moved miscellaneous deck and gravel barges in and out of the Port of 
Anchorage. Although small vessels are less common than larger ships, 
they are the most likely source of collision due to faster speeds and 
their presence in shallow water where sea otters are common. In 2005, 
there were 570 commercial fishing vessels registered in the Cook Inlet 
salmon/groundfish fleet. Of these, 86 percent were 31-40 ft in length. 
Vessels in this size class typically travel at up to 30 kn while in 
transit. The high level of ship traffic in Cook Inlet allows many sea 
otters in Cook Inlet to habituate to vessels. This will reduce risk of 
collision for the project activities when vessels are in transit.
    Although the likelihood of a project vessel striking a sea otter is 
low, we intend to require mitigation measures that we believe will 
reduce the risk of ship strike. We anticipate that vessel collisions 
involving a seismic-data-acquisition vessel towing gear, tugs towing 
rigs, or vessels conducting geophysical operations are unlikely given 
the rarity of documented collisions, the low densities of otters in 
most of the project areas, the frequent vessel traffic to which otters 
have become accustomed, and the slow vessel speeds. Vessels in transit 
and support vessels travelling at greater rates of speed are more 
likely to cause collisions.
    Mitigation measures for reducing probability of ship strike include 
speed reductions during periods of low visibility, required separation 
distances from observed otters, avoidance of nearshore travel, and use 
of navigation channels, when practicable. We believe these measures 
will further reduce the risk of collision. Given the required 
mitigation measures, the relatively slow speed of the vessel towing 
gear, the presence of marine mammal observers, and the short duration 
of many of the activities, we believe that the possibility of ship 
strike is discountable. No incidental take resulting from ship strike 
is anticipated, and this potential effect of the specified activity 
will not be discussed further in the following analysis.

Characterizing Take

    In the previous section, we discussed the components of the 
proposed action that have the potential to affect sea otters. Here we 
describe and categorize the physiological and behavioral effects that 
can be expected based on documented responses to human activities 
observed during sea otter studies. We also discuss how these behaviors 
are characterized under the MMPA.
    An individual sea otter's reaction to a human activity will depend 
on its prior exposure to the activity, its need 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. These types of responses typify the most likely 
reactions of the majority of sea otters that will be exposed to the 
applicant's activities.
    Reactions capable of causing injury are characterized as Level A 
harassment events. Examples include separation of mothers from young or 
repeatedly flushing sea otters from a haulout. Exposure to noise 
capable of causing PTS is also considered take by Level A harassment.
    Intermediate reactions that disrupt biologically significant 
behaviors are considered Level B harassment under the MMPA. The Service 
has identified the following sea otter behaviors as indicating possible 
Level B take:
     Swimming away at a fast pace on belly (i.e., porpoising);
     Repeatedly raising the head vertically above the water to 
get a better view (spyhopping) while apparently agitated or while 
swimming away;
     In the case of a pup, repeatedly spyhopping while hiding 
behind and holding onto its mother's head;
     Abandoning prey or feeding area;
     Ceasing to nurse and/or rest (applies to dependent pups);
     Ceasing to rest (applies to independent animals);
     Ceasing to use movement corridors along the shoreline;
     Ceasing mating behaviors;
     Shifting/jostling/agitation in a raft so that the raft 
disperses;
     Sudden diving of an entire raft;
     Flushing animals off a haulout.
    This list is not meant to encompass all possible behaviors; other 
situations may also indicate Level B take. It is also important to note 
that depending on the duration and severity of the above-described 
behaviors, such responses could constitute take by Level A harassment, 
e.g., repeatedly flushing sea otters from a haulout versus a single 
flushing event.

Direct and Indirect Effects

    The reactions of wildlife to disturbance can range from short-term 
behavioral changes to long-term impacts that affect survival and 
reproduction. Most sea otters will respond to human disturbance with 
nonlethal reactions that are similar to antipredator responses (Frid 
and Dill 2002). Sea otters are susceptible to predation, particularly 
from killer whales and eagles, and have a well-developed antipredator 
response to perceived threats. Sea otters will swim away, dive, or hide 
among rocks or kelp, and will sometimes spyhop (vertically raise its 
head out of the water, presumably to look around) or splash when 
threatened. Limbaugh (1961) reported that sea otters were apparently 
undisturbed by the presence of a harbor seal (Phoca vitulina), but they 
were quite concerned with the appearance of a California sea lion. They 
demonstrated their fear by actively looking above and beneath the water 
when a sea lion was swimming nearby.
    Although an increase in vigilance or a flight response is 
nonlethal, a tradeoff occurs between risk avoidance and energy 
conservation (Frid and Dill 2002). For example, southern sea otters in 
areas with heavy recreational boat traffic demonstrated changes in 
behavioral time budgeting showing decreased time resting and changes in 
haulout patterns and distribution (Benham et al. 2005; Maldini et al. 
2012). In an example described by Pavez

[[Page 10235]]

et al. (2015), South American sea lions (Otaria byronia) visited by 
tourists exhibited an increase in the state of alertness and a decrease 
in maternal attendance and resting time on land, thereby potentially 
reducing population size. In another example, killer whales (Orcinus 
orca) that lost feeding opportunities due to boat traffic faced a 
substantial (18 percent) estimated decrease in energy intake (Williams 
et al. 2006). Such disturbance effects can have population-level 
consequences. Increased disturbance rates have been associated with a 
decline in abundance of bottlenose dolphins (Tursiops sp.) (Bejder et 
al. 2006; Lusseau et al. 2006).
    These examples illustrate direct effects on survival and 
reproductive success, but disturbances can also have indirect effects. 
When disturbed by noise, animals may respond behaviorally (e.g., escape 
response), as well as physiologically (e.g., increased heart rate, 
hormonal response) (Harms et al. 1997; Tempel and Gutierrez 2003). In 
the absence of an apparent behavioral response, an animal exposed to 
noise disturbance may still experience stress and direct energy away 
from fitness-enhancing activities such as feeding and mating. The 
energy expense and physiological effects could ultimately lead to 
reduced survival and reproduction (Gill and Sutherland 2000; Frid and 
Dill 2002). Changes in behavior from anthropogenic disturbance can also 
include latent agonistic interactions between individuals (Barton et 
al. 1998). Chronic stress can lead to weakened reflexes, lowered 
learning responses (Welch and Welch 1970; van Polanen Petel et al. 
2006), compromised immune function, decreased body weight, and abnormal 
thyroid function (Selye 1979).
    The type and extent of response may be influenced by intensity of 
the disturbance (Cevasco et al. 2001), the extent of previous exposure 
to humans (Holcomb et al. 2009), the type of disturbance (Andersen et 
al. 2012), and the age and/or sex of the individuals (Shaughnessy et 
al. 2008; Holcomb et al. 2009). Despite the importance of understanding 
the effects of disturbance, few controlled experiments or field 
observations have been conducted on sea otters to address this topic.

Responses to Activities

    The available studies of sea otter behavior suggest that sea otters 
may be more resistant to the effects of sound disturbance and other 
human activities than some other marine mammals. For example, at 
Soberanes Point, California, Riedman (1983) examined changes in the 
behavior, density, and distribution of southern sea otters that were 
exposed to recorded noises associated with oil and gas activity. The 
underwater sound sources were played at a level of 110 dB and a 
frequency range of 50 to 20,000 Hz and included production platform 
activity, drillship, helicopter, and semi-submersible sounds. Riedman 
(1983) also observed the sea otters during seismic airgun shots fired 
at decreasing distances from the nearshore environment (50, 20, 8, 3.8, 
3, 1, and 0.5 nautical miles) at a firing rate of 4 shots per minute 
and a maximum air volume of 4,070 cubic inches (in\3\). Riedman (1983) 
observed no changes in the presence, density, or behavior of sea otters 
as a result of underwater sounds from recordings or airguns, even at 
the closest distance of 0.5 nautical miles (<1 km or 0.6 mi). However, 
otters did display slight reactions to airborne engine noise. Riedman 
(1983, 1984) also monitored the behavior of sea otters along the 
California coast while they were exposed to a single 100-in\3\ airgun 
and a 4,089-in\3\ airgun array. Sea otters did not respond noticeably 
to the single airgun, and no disturbance reactions were evident when 
the airgun array was as close as 0.9 km (0.6 mi).
    The limited response of sea otters to sound is probably due to 
three factors: First, sea otters use habitat where underwater noise 
exposure is limited; second, sea otters use sound differently than many 
other marine mammals; and third, sea otters show a high degree of 
behavioral plasticity in response to disturbance.
    Sea otters spend from 30 to 80 percent of their time each day at 
the surface of the water resting and grooming (Riedman 1983, 1984; 
Bodkin et al. 2004; Wolt et al. 2012). While at the surface, turbulence 
from wind and waves attenuate noise more quickly than in deeper water, 
reducing potential noise exposure (Greene and Richardson 1988; 
Richardson et al. 1995). Additionally, Lloyd's mirror effects limit the 
transference of sound from water to air. A sea otter with its head 
above water will be exposed to only a small fraction of the sound 
energy travelling through the water beneath it. Thus, the amount of 
total time spent at the surface may help limit sea otters' exposure 
during noise-generating operations.
    Many marine mammals depend on acoustic cues for vital biological 
functions, such as orientation, communication, locating prey, and 
avoiding predators. However, sea otters do not rely on sound to orient 
themselves, locate prey, or communicate underwater. Sea otters use 
sound for communication in air (especially mothers and pups; McShane et 
al. 1995) and may avoid predators by monitoring underwater sound. Davis 
et al. (1987) documented sea otters retreating from simulated killer 
whale vocalizations. Otters are not known to vocalize underwater and do 
not echolocate; therefore, masking of communications by anthropogenic 
sound is less of a concern than for other mammals.
    Sea otters generally show a high degree of tolerance to noise. In 
another study using prerecorded sounds, Davis et al. (1988) exposed 
both northern sea otters in Simpson Bay, Alaska, and southern sea 
otters in Morro Bay, California, to a variety of airborne and 
underwater sounds, including a warble tone, sea otter pup calls, killer 
whale calls, airhorns, and an underwater acoustic harassment system 
designed to drive marine mammals away from crude oil spills. The sounds 
were projected at a variety of frequencies, decibel levels, and 
intervals. The authors noted that certain acoustic stimuli could cause 
a startle response and result in dispersal. However, the disturbance 
effects were limited in range (no responses were observed for otters 
approximately 100-200 m (328-656 ft) from the source of the stimuli), 
and habituation to the stimuli was generally very quick (within hours 
or, at most, 3 to 4 days).
    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, and possibly more important than underwater noise in prompting the 
animals' reactions. When sea otters have displayed behavioral reactions 
in response to acoustic stimuli, these responses were often short-
lived; the otters resumed normal activities soon after a new sound was 
introduced (Davis et al. 1987, 1988).
    Among sea otters, exposure to moderate to high levels of underwater 
noise is not likely to cause injury and mortality from stranding or 
excessive nitrogen accumulation, both of which are concerns for other 
species of marine mammals, but the possibility of hearing loss cannot 
be discounted. The consequences of hearing loss among otters remains 
unknown. We have much more information about the observable

[[Page 10236]]

responses of sea otters to human activities.
    Stimuli from shoreline construction activities, aircraft, and 
vessel traffic, including noise, are likely to cause some level of 
disturbance. Populations of sea otters in Alaska have been known to 
avoid areas with heavy boat traffic but return to those same areas 
during seasons with less traffic (Garshelis and Garshelis 1984). Sea 
otters in Alaska have shown signs of disturbance (escape behaviors) in 
response to the presence and approach of survey vessels, including: 
Otters diving and/or actively swimming away from a boat; hauled-out 
otters entering the water; and groups of otters disbanding and swimming 
in multiple different directions (Udevitz et al. 1995).
    In Cook Inlet, otters were observed riding the tides past a new 
offshore drilling platform while drilling was being conducted. Otters 
drifting on a trajectory that would have taken them within 500 m (0.3 
mi) of the rig tended to swim to change their angle of drift to avoid a 
close approach, although noise levels from the work were near the 
ambient level of underwater noise (BlueCrest 2013).
    Sea otter behavior is suggestive of a dynamic response to 
disturbance, influenced by the intensity and duration of the source. 
Otters initially abandon areas when disturbed and return when the 
disturbance ceases. Groups of sea otters in two locations in California 
showed markedly different responses to kayakers approaching to within 
specific distances, suggesting a different level of tolerance between 
the groups (Gunvalson 2011). Benham (2006) found evidence that the 
otters exposed to high levels of recreational activity may have become 
more tolerant than individuals in less-disturbed areas.
    Some individual otters will habituate to the presence of project 
vessels, noise, and activity. Sea otters often seem quite tolerant of 
boats or humans nearby (e.g., Calkins 1979). 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). Boat traffic, commercial and 
recreational, is common in Cook Inlet. However, there are seasonal 
(i.e., temporal) and spatial components to vessel traffic. Both 
recreational and commercial vessel traffic in Kachemak Bay is much 
higher than in western Cook Inlet, and all traffic is much higher in 
summer than in other months. Some sea otters in the area of activity 
are likely to have already become habituated to vessel traffic and 
noise caused by vessels, whereas for others, the proposed activities 
will be a novel experience and will elicit a more intense response.
    Some degree of disturbance is also possible from unmitigated 
aircraft activities. Individual sea otters in Cook Inlet will show a 
range of responses to noise from low-flying aircraft. Some may abandon 
the flightpath area and return when the disturbance has ceased. Based 
on the observed movement patterns of wild sea otters (i.e., Lensink 
1962; Kenyon 1969, 1981; Garshelis and Garshelis 1984; Riedman and 
Estes 1990; Tinker and Estes 1996, and others), we expect that some 
individuals, independent juveniles, for example, will respond to the 
proposed activities by dispersing to areas of suitable habitat nearby, 
while others, especially breeding-age adult males, will not be 
displaced by overflights. Mitigation measures will stipulate a minimum 
of 305 m (1,000 ft) flight altitude to avoid harassment of otters.
    Given the observed responses of sea otters to sources of 
disturbance, it is likely that some degree of take by harassment will 
occur due to underwater noise stimuli associated with the proposed 
activities. Some otters will likely show startle responses, change 
direction of travel, disperse from the area, or dive. Sea otters 
reacting to project activities may expend energy and divert time and 
attention from biologically important behaviors, such as feeding. Some 
effects may be undetectable in observations of behavior, especially the 
physiological effects of chronic and cumulative noise exposure. Air and 
vessel traffic, commercial and recreational, is routine in Cook Inlet. 
Construction activities are common. Some sea otters in the area of 
activity may become habituated to noise caused by the project due to 
the existing continual air traffic in the area and will have little, if 
any, reaction to project activities.

Mitigation and Monitoring

    If an ITR is issued, it must specify means for effecting the least 
practicable adverse impact on sea otters and their habitat, paying 
particular attention to habitat areas of significance, and on the 
availability of sea otters for taking for subsistence uses by coastal-
dwelling Alaska Natives. These proposed measures are outlined in Sec.  
18.137 Mitigation.
    In evaluating what mitigation measures are appropriate to ensure 
the least practicable adverse impact on species or stocks and their 
habitat, as well as subsistence uses, we considered the manner in 
which, and the degree to which, the successful implementation of the 
measures are expected to reduce impacts to sea otters, stocks, and 
their habitat, as well as subsistence uses. We considered the nature of 
the potential adverse impact being mitigated (likelihood, scope, 
range), the likelihood the measures will be effective, and the 
likelihood the measures will be implemented. 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 following mitigation measures will 
be applied:
     Development of marine mammal monitoring and mitigation 
plans;
     Establishment of an exclusion zone (EZ) and safety zone 
(SZ) during noise-generating work;
     Visual mitigation monitoring by designated protected 
species observers (PSOs);
     Site clearance before startup;
     Shutdown procedures;
     Power-down procedures;
     Ramp-up procedures; and
     Vessel strike avoidance measures.
    A marine mammal mitigation and monitoring plan that will identify 
the specific avoidance and minimization measures an applicant will take 
to reduce effects to otters. It will describe the project in detail, 
assess the effects, identify effective means to avoid effects, and 
describe specific methods for limiting effects when they cannot be 
avoided.
    During ``noise-generating work'' (work that creates underwater 
sound louder than 160 dB and within the frequency hearing range of sea 
otters), an applicant will establish and monitor an exclusion zone 
(EZ). This zone is defined as the area surrounding a sound source in 
which all operations must be shut down in the event a sea otter enters 
or is about to enter this zone based on distances to Level A 
thresholds. Any otter detected within this zone will be exposed to 
sound levels likely to cause take by Level A harassment. The safety 
zone (SZ) is an area larger than the EZ and is defined as the area in 
which otters may experience noise above the Level B exposure threshold. 
Sea otters observed inside the SZ are likely to be disturbed by 
underwater noise, and each otter within the SZ will be counted as one 
Level B take. In the event a sea otter is in or about to enter the 
zone, operations will be powered down, when practicable, to minimize 
take. Radii of each SZ and EZ will be specified in each LOA issued 
under this proposed ITR. The methodology for calculation of the radii 
will be described in each LOA

[[Page 10237]]

and is identified in proposed Sec.  18.137 Mitigation. A minimum 10-m 
(33-ft) shutdown zone will be observed for all in-water construction 
and heavy machinery.
    PSOs will be stationed on the source vessel or at a suitable 
vantage point with maximum view of the SZ and EZ. The PSOs will clear 
the EZ prior to the start of daily activities for which take has been 
requested or if activities have been stopped for longer than a 30-
minute period. The PSOs will ensure the EZ is clear of sea otters for a 
period of 30 minutes. Clearing the EZ means no sea otters have been 
observed within the EZ for that 30-minute period. If any sea otters 
have been observed within the EZ, ramp-up cannot start until the sea 
otter has left the EZ or has not been observed in the EZ for a 30-
minute period prior to the start of the survey.
    A power-down procedure will be in place during seismic work. It 
will involve reducing the number of airguns in use, which reduces the 
EZ or SZ radius. In contrast, a shutdown procedure occurs when all 
airgun activity is suspended immediately. During a power down, a single 
airgun (``mitigation gun'') remains operational, maintaining a sound 
source with a much-reduced EZ. If a sea otter is detected outside of 
either the SZ or EZ but is likely to enter that zone, the airguns may 
be powered down before the animal is within the radius, as an 
alternative to a complete shutdown. Likewise, if a sea otter is already 
within the SZ when first detected, the airguns will be powered down if 
this is a reasonable alternative to an immediate shutdown. If a sea 
otter is already within the EZ when first detected, the airguns will be 
shut down immediately. All power down events will be at the discretion 
of the operator in cooperation with the PSOs. The applicant has 
determined that it is not practicable to power down in response to all 
sea otters within the SZ, and that to do so would incapacitate the 2D 
and 3D seismic operations. Because power down events will be 
discretionary, all otters within the SZ will be assumed to experience 
Level B take regardless of whether a power down is conducted. Although 
there is no calculated reduction of take estimated for this mitigation 
measure due to uncertainty in its application, it is expected that some 
unquantified benefits to sea otters will be realized whenever the 
operator powers down to reduce sea otter noise exposures.
    A shutdown will occur when all underwater sound generation that is 
louder than 160 dB and within the frequency hearing range of sea otters 
is suspended. The sound source will be shut down completely if a sea 
otter approaches the EZ or appears to be in distress due to the noise-
generating work. The shutdown procedure will be accomplished within 
several seconds of the determination that a sea otter is either in or 
about to enter the EZ. Following a shutdown, noise-generating work will 
not resume until the sea otter has cleared the EZ. Any shutdown due to 
a sea otter sighting within the EZ must be followed by a 30-minute all-
clear period and then a standard, full ramp-up. Any shutdown for other 
reasons resulting in the cessation of the sound source for a period 
greater than 30 minutes must also be followed by full ramp-up 
procedures.
    A ``ramp-up'' procedure will be in place to gradually increase 
sound volume at a specified rate. Ramp-up is used at the start of 
airgun operations, including after a power down, shutdown, or any 
period greater than 10 minutes in duration without airgun operations. 
The rate of ramp-up will be no more than 6 dB per 5-minute period. 
Ramp-up will begin with the smallest gun in the array that is being 
used for all airgun array configurations. The ramp-up procedure for 
pipe/pile driving involves initially starting with soft strikes. If the 
complete EZ has not been visible for at least 30 minutes prior to the 
start of operations, ramp-up will not commence unless the mitigation 
gun has been operating during the interruption of seismic survey 
operations. It will not be permissible to ramp up the 24-gun source 
from a complete shutdown in thick fog or at other times when the outer 
part of the EZ is not visible. Ramp-up of the airguns will not be 
initiated if a sea otter is sighted within the EZ at any time.
    A speed or course alteration is appropriate if a sea otter is 
detected outside the EZ and, based on its position and relative motion, 
is likely to enter the EZ, and a vessel's speed and/or direct course 
may, when practical and safe, be changed. This technique can be used in 
coordination with a power-down procedure. The sea otter activities and 
movements relative to the seismic and support vessels will be closely 
monitored to ensure that the sea otter does not approach within the EZ. 
If the mammal appears likely to enter the EZ, further mitigative 
actions will be taken, i.e., further course alterations, power down, or 
shutdown of the airguns.
    A stakeholder engagement plan is required to determine whether 
conflicts with subsistence activities are likely to arise. If so, the 
applicant will be required to develop a plan of cooperation (POC), 
which will identify what measures have been taken and/or will be taken 
to minimize adverse effects on the availability of sea otters for 
subsistence purposes. The POC will include the applicant's plan to meet 
with the affected communities, both prior to and while conducting the 
activity, to resolve conflicts and to notify the communities of any 
changes in the operation. The POC will help coordinate activities with 
local stakeholders and thus subsistence users, minimize the risk of 
interfering with subsistence hunting activities, and keep current as to 
the timing and status of the subsistence hunts. The applicant's 
stakeholder engagement plan is provided with the applicant's petition, 
which is available as described in ADDRESSES. Meetings and 
communication will be coordinated with Cook Inlet Regional Citizens 
Advisory Council, local landowners, government and community 
organizations, and environmental groups.
    In order to issue an LOA for an activity, section 101(a)(5)(A) of 
the MMPA states that the Service must set forth ``requirements 
pertaining to the monitoring and reporting of such taking.'' The 
Service's implementing regulations at 50 CFR 18.27(d)(1)(vii) indicate 
that requests for authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting. Effective 
reporting is critical to compliance as well as ensuring that the most 
value is obtained from the required monitoring. The applicant will 
employ PSOs to conduct visual project monitoring. During 2D and 3D 
seismic surveys, Hilcorp and Harvest have agreed to conduct aerial 
overflights for avoidance of other marine mammal species, which will 
improve monitoring of sea otters. Additional proposed monitoring and 
reporting requirements are at Sec.  18.138 Monitoring and Sec.  18.139 
Reporting requirements.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered, we have preliminarily determined 
that the proposed mitigation measures provide the means of effecting 
the least practicable adverse impact on sea otter stocks and their 
habitat.

Estimated Incidental Take

    This section provides the number of incidental takes estimated to 
occur because of the proposed activities. The number of individuals 
taken and the number of takes per individual are then analyzed to make 
the required small numbers and negligible impact determinations.

[[Page 10238]]

Estimating Exposure Rates

    The Service anticipates that incidental take of sea otters may 
occur during the proposed activities in Cook Inlet. Noise, aircraft, 
vessels, and human activities could temporarily interrupt feeding, 
resting, and movement patterns. Elevated underwater noise levels from 
seismic surveys may cause short-term, nonlethal, but biologically 
significant changes in behavior that the Service considers harassment. 
Pile-driving and other constructing activities along the shoreline may 
have similar effects and could cause behavioral disturbance leading to 
take. Harassment (Level A or B) is the only type of take expected to 
result from these activities; no lethal take is expected.
    The number of animals affected will be determined by the 
distribution of animals and their location in proximity to the project 
work. Although we cannot predict the outcome of each encounter, it is 
possible to consider the most likely reactions, given observed 
responses of marine mammals to various stimuli.
    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 the 
number of otters exposed to all proposed activities.
    No separate exposure evaluation was done for activities that do not 
generate underwater sound. Nearly 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 along the shoreline 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. Aircraft support 
activities will be conducted without a corresponding underwater sound 
component, but no take is expected from this source of disturbance; see 
``Airborne Sounds.''
    To estimate the numbers of sea otters likely to experience take, we 
first calculated the number of otters in Cook Inlet that occur within 
the project area. The number of otters was calculated from density 
multiplied by project area. Density was estimated according to region 
in Cook Inlet.
    Density data for Kamishak and the East side of Cook Inlet along the 
shore of the Kenai Peninsula was derived from aerial surveys conducted 
in May 2017 (Garlich-Miller et al. 2018). Surveys were not conducted 
for central Cook Inlet in 2017, and 2017 surveys for western Cook Inlet 
north of Kamishak did not yield useful results. Therefore, the density 
for those regions was derived from the 2002 surveys conducted by Bodkin 
et al. (2003) and corrected for population growth proportional to the 
growth rate of Cook Inlet as a whole, as determined from comparison of 
the 2002 and 2017 surveys. Density values (in otters per km\2\) were 
1.7 in East Cook Inlet (excluding Kachemak Bay and the outer Coast of 
Kenai Peninsula south and east of Seldovia), 3.53 in Kamishak Bay, and 
0.026 in West and Central Cook Inlet. There are no density data for sea 
otters in the middle Cook Inlet region north of approximately 
60[deg]14' N (the latitude of Clam Gulch), and otters are uncommon 
north of about 60[deg]24' N. Therefore, densities north of Clam Gulch 
were conservatively assumed to equal the 2002 mid-Cook Inlet survey 
region density of 0.01 per km\2\ from Bodkin et al. (2003).
    The geographic area of activity covers approximately 11,084 km\2\ 
(4,280 mi\2\) in Cook Inlet. Of this area, 1,572 km\2\ (607 mi\2\) is 
in East Cook Inlet, 725 km\2\ (280 mi\2\) in Kamishak Bay, 4,341 km\2\ 
(1,676 mi\2\) in West and Central Cook Inlet, and 4,445 km\2\ (1,716 
mi\2\) in Cook Inlet north of the normal range of sea otters. The total 
number of otters within the project area was calculated to be 5,389 
otters ((1,572 x 1.7) + (725 x 3.53) + (4,341 x 0.026) + (4,445 x 0.01) 
[ap] 5,389).
    Not all otters in the project area will be exposed to project 
activities. Many activities associated with oil and gas exploration, 
development, production, and transportation may result in underwater 
sounds and potential disturbance to marine mammals, but will not meet 
Levels A and B acoustic harassment criteria. The acoustic 
characteristics of the different project activities are described in 
Table 3. Only those specific activities with the likelihood of meeting 
the acoustic exposure criteria and occurring in the normal range of sea 
otters were evaluated for estimation of potential Levels A and B 
harassment. Specifically, Hilcorp's activities include 2D and 3D 
seismic surveys, vibratory driving of sheet piles at the Iniskin 
Peninsula causeway in Chinitna Bay, sub-bottom profilers used in high- 
and low-resolution geohazard surveys, drive-pipe installation, vertical 
seismic profiling, tugs towing the rig for exploratory wells, plug and 
abandon activities, and use of water jets or hydraulic grinders during 
routine maintenance. AGDC's activities include pile driving and anchor 
handling.
    The number of otters that will be exposed to underwater sound 
levels capable of causing take by Level A and Level B harassment from 
specific project elements was estimated using the methods recommended 
by NMFS (2018a,b) for otariid pinnipeds. We multiplied the estimated 
area in which underwater sound in the frequency range of otter hearing 
from each activity will exceed 160 dB, termed the ``area of 
ensonification'' (km\2\), by the density of sea otters in that area 
(number (#) of otters/km\2\) to estimate the number of otters in the 
ensonified area. This value was then multiplied by the duration of the 
activity (# of days) over the course of the 5-year regulatory period to 
get the total number of exposures to sound above the thresholds for 
take.

Predicting Behavioral Response Rates

    Although we cannot predict the outcome of each encounter between a 
sea otter and the equipment and vessels used for the proposed 
activities, it is possible to consider the most likely reactions. Sea 
otters have shown little reaction to underwater sounds but the presence 
of vessels may elicit stronger behavioral (see Responses to 
Activities). Whether an individual animal responds behaviorally to the 
presence of vessels and equipment is dependent upon several variables, 
including the activity of the animal prior to stimulus, whether the 
animal is habituated to similar disturbances, whether the animal is in 
a state of heightened awareness due to recent disturbances or the 
presence of predators, group size, the presence of pups, and the 
temperament of the individual animals. We assumed all animals exposed 
to underwater sound levels that meet acoustic criteria would experience 
Level A or Level B take.

Calculating Take

    The total take of sea otters from the proposed oil and gas 
activities in Cook Inlet was estimated by calculating the number of 
otters in the ensonified area during the full duration of the project.
Distances to Thresholds
    To calculate the ensonified area, we first estimated the distances 
that underwater sound will travel before attenuating to levels below 
thresholds

[[Page 10239]]

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) using 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). The only exceptions to the use of the practical spreading model 
were made when data was available from a site-specific sound source 
verification of substantially similar equipment used and powered in a 
similar manner to that proposed by the applicant.
    Model estimates incorporated operational and environmental 
parameters for each activity. For example, sound levels at the source 
are shown in Table 3, and characteristics of the sound produced are 
shown in Table 6. Weighting factor adjustments were used for SEL (sound 
exposure level) calculations based on NMFS Technical Guidance (2018b). 
Operational parameters were estimated from the description of 
activities.
    The distances to the modelled Level A and Level B thresholds are 
shown in Table 7. Each estimate represents the radial distance away 
from the sound source within which a sea otter exposed to the sound of 
the activity is expected to experience take by Level A or Level B 
harassment.

                                  Table 6--Assumptions Used in Calculating Distances to Level A and Level B Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Source     Pulse
            Activity                 Type of source      Source level \1\    WFA \2\    velocity   duration    Repetition rate       Duration per day
                                                                              (kHz)      (m/s)       (s)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2D/3D seismic...................  Mobile Impulsive...  217 @100 m (185              1       2.05        N/A  every 6 s.........  N/A.
                                                        dBSEL @100 m).
Sub bottom profiler.............  Mobile Impulsive...  212 @1 m...........          4       2.05       0.02  every 0.30 s......  N/A.
Impact pile driving.............  Stationary           <=195 @10 m........          2        N/A        N/A  1,560 strikes/hr..  <=5.5 hrs/day.
                                   Impulsive.
Pipe driving....................  Stationary           <=195 @55 m........          2        N/A       0.02  <=1,560 strikes/hr  <=4.8 hrs/day.
                                   Impulsive.
Vertical seismic profiling......  Stationary           227 @1 m...........          1        N/A       0.02  every 6 s.........  4 hrs/day.
                                   Impulsive.
Impact sheet piling.............  Stationary           190 @10 m..........          2        N/A       0.02  1,560 strikes/hr..  3 hrs/day.
                                   Impulsive.
Vibratory sheet piling..........  Stationary Non-      160 @10 m..........        2.5        N/A        N/A  N/A...............  <=4.8 hrs/day.
                                   impulsive.
Water jet.......................  Stationary Non-      176 @1 m...........          2        N/A        N/A  N/A...............  0.5 hrs/day.
                                   impulsive.
Hydraulic grinder...............  Stationary Non-      159 @1m............          2        N/A        N/A  N/A...............  0.5 hrs/day.
                                   impulsive.
Tug towing......................  Mobile Non-          191 @1 m...........        1.5       1.54        N/A  N/A...............  6 hrs/day.
                                   impulsive.
Anchor handling.................  Mobile Non-          179 @1 m...........        1.5       1.54        N/A  N/A...............  3 hrs/day.
                                   impulsive.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Source level is given in dBrms, unless otherwise indicated, as measured at the given distance from the source in meters.
\2\ Weighting Factor Adjustment.


                  Table 7--Calculated Distance in Meters (m) to Level A and Level B Thresholds
----------------------------------------------------------------------------------------------------------------
                                                            Level A--NMFS Otariid                Level B--USFWS
                                              ------------------------------------------------------------------
                   Activity                               Impulsive             Non-impulsive         Both
                                              ------------------------------------------------------------------
                                                 232 dB peak     203 dB SEL      219 dB SEL        160 dB rms
----------------------------------------------------------------------------------------------------------------
2D/3D seismic................................              10            1.32             N/A              7,330
Sub-bottom profiler..........................            0.05            0.80             N/A              2,929
Pipe driving, Chinitna Bay...................            0.19            5.21             N/A              1,630
VSP..........................................            0.46          284.84             N/A              2,470
Vibratory sheet pile driving.................             N/A             N/A            0.63                 10
Water jet....................................             N/A             N/A            0.56              11.66
Hydraulic grinder............................             N/A             N/A            0.04               0.86
Tug towing...................................             N/A             N/A            0.00             107.98
18- and 24-inch pipe, impact.................            0.22           50.53             N/A           1,874.85
48- and 60-inch pipe, impact.................            0.34          147.99             N/A           2,154.43
all sizes pipe, vibratory....................             N/A             N/A            3.30              46.42
Sheet pile, impact...........................            0.16           68.69              NA              1,000
Sheet pile, vibratory........................             N/A             N/A            0.71                 10
Anchor handling..............................             N/A             N/A            0.00              37.41
----------------------------------------------------------------------------------------------------------------

Area and Duration
    The area of ensonification is the area in which an animal exposed 
to underwater sound is expected to experience take from Level A or 
Level B harassment. The area of a circle (A=[pi]r \2\) where r is the 
distance to the Level A or Level B threshold was used to calculate the 
area of ensonification for impulsive stationary sources (pipe driving, 
vertical seismic profiling), non-impulsive stationary sources (water 
jets, hydraulic grinders, vibratory pile driving), and non-impulsive 
mobile sources (tugs towing rigs and anchor handling). For impulsive 
mobile sources (2D/3D seismic, sub-bottom profiler), the area was then 
multiplied by the distance of the line to be surveyed each day. Otters 
spend most of their time at the water's surface or below their last

[[Page 10240]]

surface location, so a circle with the sound source at its center is a 
reasonable representation of the ensonified area. For shoreline 
activities, the area of the circle is divided by two to remove the area 
that lies above the water line. Details about the assumptions used in 
calculations of the area of ensonification for each proposed activity 
are available in the applicant's petition, which is available as 
described in ADDRESSES.
    The area of ensonification was then multiplied by the density of 
otters in the applicable region of Cook Inlet to estimate the number of 
otters that might be taken. The results are shown in Table 8. The total 
number of sea otters in Cook Inlet expected to be taken by Level A 
harassment over the 5-year course of this proposed ITR is 1. The total 
expected to be taken by Level B harassment over the 5-year course of 
this proposed ITR is 93.
    The number of otters taken from each stock was estimated by 
categorizing activity by its location relative to sea otter stock 
boundaries. Some activities will occur in both the southcentral and 
southwestern stock boundaries. For these, take of sea otters was 
assigned in proportion to the area of the activity within each stock 
region. Of the estimated 93 otters expected to be taken by Level B 
harassment, 9 otters will belong to the southwest stock, and 84 to the 
southcentral stock. The one otter estimated to experience Level A take 
is likely to be from the southcentral stock.
    The next step in analysis was to multiply the estimate of the 
number of individual otters taken by the duration of each activity to 
calculate the total number of takes. The total number of takes is 
higher than the number of otters taken because, for example, a resident 
otter may be taken on each day of noise-generating activity. For some 
projects, like the 3D seismic survey, the design of the project is well 
developed; therefore, the duration is well defined. However, for some 
projects, the duration is not well developed, such as activities around 
the lower Cook Inlet well sites. In each case, the calculations are 
based on the applicant's best forecast of activities in the 5-year ITR 
period. The assumptions regarding duration of these activities are 
presented in the applicant's petition. The durations used for each 
activity are provided in Table 9. We assumed one take per day 
regardless of duration of work within a day. The resulting estimate of 
the total number of Level B takes expected from proposed oil and gas 
activities in Cook Inlet from 2019 through the date 5 years from the 
effective date of the final rule is 1,663. The total number of takes by 
activity are also presented in Table 9.
    The total number of takes from each stock was calculated in the 
same manner as for estimation of individuals taken. The proportion of 
takes was set equal to the proportion of an activity occurring inside a 
stock boundary. The total number of takes of sea otters from the 
southwest stock is 410. The take number from the southcentral stock is 
1,256. A summary of take is shown in Table 10.

                                                   Table 8--Number of Sea Otters Expected To Be Taken
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                              Level A                         Level B
                                                                                         ---------------------------------------------------------------
                 Applicant                            Activity              Density (#/              Impulsive             Non-impulsive
                                                                              km\2\)     ------------------------------------------------     160 rms
                                                                                              232 pk          203 SEL         219 SEL
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hilcorp/Harvest Alaska....................  2D seismic..................           1.705           0.102           0.013  ..............          74.986
                                            3D seismic..................           0.026           0.019           0.003  ..............          14.118
                                            Vibratory sheet pile driving           0.026  ..............  ..............           0.000           0.000
                                            Sub-bottom profiler-LCI.....           0.026           0.000           0.000  ..............           1.505
                                            Sub-bottom profiler-NCI.....           0.010           0.000           0.000  ..............           0.579
                                            Sub-bottom profiler-TB......           0.010           0.000           0.000  ..............           0.579
                                            Sub-bottom profiler-MCI.....           0.010           0.000           0.000  ..............           0.072
                                            Pipe driving-LCI............           0.026           0.000           0.000  ..............           0.217
                                            Pipe driving-TB.............           0.010           0.000           0.000  ..............           0.083
                                            VSP-LCI.....................           0.026           0.000           0.005  ..............           0.498
                                            VSP-TB......................           0.010           0.000           0.002  ..............           0.192
                                            Hydraulic grinder...........           0.010  ..............  ..............           0.000           0.000
                                            Water jet...................           0.010  ..............  ..............           0.000           0.000
                                            Tugs towing rig-LCI.........           0.026  ..............  ..............           0.000           0.000
                                            Tugs towing rig-NCI.........           0.010  ..............  ..............           0.000           0.000
                                            Tugs towing rig-TB..........           0.010  ..............  ..............           0.000           0.000
AGDC......................................  Product Loading Facility....  ..............  ..............  ..............  ..............  ..............
                                            48-inch impact..............           0.010           0.000           0.000  ..............           0.073
                                            60-inch impact..............           0.010           0.000           0.000  ..............           0.073
                                            Temporary MOF...............  ..............  ..............  ..............  ..............  ..............
                                            18-inch vibratory...........           0.010  ..............  ..............           0.000           0.000
                                            24-inch impact..............           0.010           0.000           0.000  ..............           0.054
                                            48-inch impact..............           0.010           0.000           0.000  ..............           0.073
                                            60-inch vibratory...........           0.010  ..............  ..............           0.000           0.000
                                            sheet vibratory.............           0.010  ..............  ..............           0.000           0.000
                                            Mainline MOF................  ..............  ..............  ..............  ..............  ..............
                                            sheet vibratory.............           0.010  ..............  ..............           0.000           0.000
                                            sheet impact................           0.010           0.000           0.000  ..............           0.016
                                            Anchor handling.............        0.010000  ..............  ..............           0.000           0.000
                                                                         -------------------------------------------------------------------------------
    Total.................................  ............................  ..............           0.122           0.025           0.000          93.117
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 10241]]


                                               Table 9--Estimate of Total Take for Each Proposed Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                              Level A                         Level B
                                                                                         ---------------------------------------------------------------
                 Applicant                            Activity               Duration                Impulsive             Non-impulsive
                                                                              (days)     ------------------------------------------------     160 rms
                                                                                              232 pk          203 SEL         219 SEL
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hilcorp/Harvest Alaska....................  2D seismic..................          10.000           1.023           0.135  ..............         749.859
                                            3D seismic..................          60.000           1.156           0.152  ..............         847.090
                                            Vibratory sheet pile driving           5.000  ..............  ..............           0.000           0.000
                                            Sub-bottom profiler-LCI.....          31.093           0.001           0.013  ..............          46.783
                                            Sub-bottom profiler-NCI.....           7.773           0.000           0.001  ..............           4.498
                                            Sub-bottom profiler-TB......          15.547           0.000           0.002  ..............           8.997
                                            Sub-bottom profiler-MCI.....           2.915           0.000           0.000  ..............           0.211
                                            Pipe driving-LCI............           3.000           0.000           0.000  ..............           0.651
                                            Pipe driving-TB.............           1.500           0.000           0.000  ..............           0.125
                                            VSP-LCI.....................           2.000           0.000           0.010  ..............           0.997
                                            VSP-TB......................           1.000           0.000           0.002  ..............           0.192
                                            Hydraulic grinder...........          10.500  ..............  ..............           0.000           0.000
                                            Water jet...................          10.500  ..............  ..............           0.000           0.000
                                            Tugs towing rig-LCI.........          14.000  ..............  ..............           0.000           0.013
                                            Tugs towing rig-NCI.........          21.000  ..............  ..............           0.000           0.008
                                            Tugs towing rig-TB..........          18.000  ..............  ..............           0.000           0.007
AGDC......................................  Product Loading Facility....  ..............  ..............  ..............  ..............  ..............
                                            48-inch impact..............          14.000           0.000           0.005  ..............           1.021
                                            60-inch impact..............          26.500           0.000           0.009  ..............           1.932
                                            Temporary MOF...............  ..............  ..............  ..............  ..............  ..............
                                            18-inch vibratory...........          21.804  ..............  ..............           0.000           0.001
                                            24-inch impact..............           1.750           0.000           0.000  ..............           0.094
                                            48-inch impact..............           1.750           0.000           0.001  ..............           0.128
                                            60-inch vibratory...........           4.300  ..............  ..............           0.000           0.000
                                            sheet vibratory.............          26.104  ..............  ..............           0.000           0.000
                                            Mainline MOF................  ..............  ..............  ..............  ..............  ..............
                                            sheet vibratory.............            2.68  ..............  ..............           0.000           0.000
                                            sheet impact................            1.68           0.000           0.000  ..............           0.026
                                            Anchor handling.............           19.00  ..............  ..............           0.000            0.00
                                                                         -------------------------------------------------------------------------------
    Total.................................  ............................  ..............           2.180           0.331           0.000       1,662.634
--------------------------------------------------------------------------------------------------------------------------------------------------------


          Table 10--Summary of Estimates of Sea Otter Take by Level A and Level B Harassment and Stock
----------------------------------------------------------------------------------------------------------------
                                                                     Southwest     Southcentral
                 Type                         Unit of take             stock           stock            Sum
----------------------------------------------------------------------------------------------------------------
Level A...............................  Number of takes.........               0               3               3
Level B...............................  Number of takes.........             410           1,253           1,663
                                                                 -----------------------------------------------
    Total.............................  Number of takes.........             410           1,256           1,666
----------------------------------------------------------------------------------------------------------------
Level A...............................  Number of otters taken..               0               1               1
Level B...............................  Number of otters taken..               9              84              93
                                                                 -----------------------------------------------
    Total.............................  Number of otters taken..               9              85              94
----------------------------------------------------------------------------------------------------------------

Annual Estimates of Take
    The estimates of exposures by activity and location discussed in 
the previous section are not representative of the estimated exposures 
per year (i.e., annual takes). It is difficult to characterize each 
year accurately because many of the activities are progressive (i.e., 
they depend on results and/or completion of the previous activity). 
This results in much uncertainty in the timing, duration, and complete 
scope of work. Each year, each applicant will submit an application for 
an LOA with the specific details of the planned work for that year and 
estimated take numbers. Table 11 summarizes the activities according to 
a scenario presented in the applicant's petition. This scenario 
combines the most realistic progression by Hilcorp and Harvest with an 
optimistic scenario for AGDC. In the first season, Hilcorp and Harvest 
plan to conduct 3D seismic surveys. In the second season, in lower Cook 
Inlet they plan to conduct activities for one well; in middle Cook 
Inlet, they plan to conduct plugging and abandonment activities in 
North Cook Inlet Unit and two wells in the Trading Bay area. In the 
third season, activities include drilling two wells in lower Cook 
Inlet. The final well in lower Cook Inlet is planned for the fourth 
season.
    The timing of AGDC's activities will depend on final authorizations 
and funding and may begin in 2020 rather than 2019. Season 1 will be 
the first year of project work regardless of year, followed by season 2 
during the second year, etc. Work will generally occur from April 
through October. Material offloading facilities will be constructed in 
the first and second season, and a product loading facility will be 
installed during seasons 2, 3, and 4. Installation of the gas pipeline 
is planned for seasons 3 and 4 as well. The anticipated timing of 
project components that are

[[Page 10242]]

likely to meet or exceed criteria for take of sea otters is shown in 
Table 11.
    The annual number of takes and the number of sea otters taken was 
then estimated by allocating the total expected take by proportion of 
each project component occurring in each year. For example, the 2D 
seismic surveys are planned for year 3, so all takes and otters taken 
during 2D seismic surveys were assigned to year 3. The resulting 
estimates of total take by year and number of otters taken by year are 
shown in Table 12.

                                  Table 11--Noise-Generating Activities by Year
        [Activities are those with source levels above 160 dB rms within frequencies heard by sea otters]
----------------------------------------------------------------------------------------------------------------
              Year                             Applicant                         Activity               Area
----------------------------------------------------------------------------------------------------------------
2019--Season 1.................  Hilcorp/Harvest......................   3D seismic.......  LCI
                                                                         Geohazard........  LCI
                                                                         Sheet pile         LCI
                                                                         driving in Chinitna Bay.   MCI
                                                                         Pipeline
                                                                         maintenance (geohazard,
                                                                         water jet, grinder).
                                 AGDC.................................   Sheet pile         MCI
                                                                         driving at TMOF.           MCI
                                                                         Sheet pile
                                                                         driving at MMOF.
2020--Season 2.................  Hilcorp/Harvest......................   Drilling           LCI
                                                                         activities (tugs,          MCI
                                                                         geohazard, pipe driving,   MCI
                                                                         VSP) at 1 well.            MCI
                                                                         Drilling
                                                                         activities (tugs,
                                                                         geohazard, pipe driving,
                                                                         VSP) at 2 wells in TB.
                                                                         P&A activities
                                                                         (tugs, geohazard) at 1
                                                                         well in the NCI.
                                                                         Pipeline
                                                                         maintenance (geohazard,
                                                                         water jet, grinder).
                                 AGDC.................................   Impact pile        LCI
                                                                         driving at PLF: 80 48-     MCI
                                                                         inch piles, 63 60-inch     MCI
                                                                         piles.
                                                                         Sheet pile
                                                                         driving at TMOF.
                                                                         Sheet pile
                                                                         driving at MMOF.
2021--Season 3.................  Hilcorp/Harvest......................   Drilling           LCI
                                                                         activities (tugs,          LCI
                                                                         geohazard, pipe driving,   MCI
                                                                         VSP) at 2 wells.
                                                                         2D seismic.......
                                                                         Pipeline
                                                                         maintenance (geohazard,
                                                                         water jet, grinder).
                                 AGDC.................................   Impact pile        LCI
                                                                         driving at PLF: 40 48-     MCI
                                                                         inch piles, 80 60-inch
                                                                         piles.
                                                                         Anchor handling
                                                                         for pipeline installation.
2022--Season 4.................  Hilcorp/Harvest......................   Drilling           LCI
                                                                         activities (tugs,          MCI
                                                                         geohazard, pipe driving,
                                                                         VSP) at 1 well.
                                                                         Pipeline
                                                                         maintenance (geohazard,
                                                                         water jet, grinder).
                                 AGDC.................................   Impact pile        LCI
                                                                         driving at PLF: 10 48-     MCI
                                                                         inch piles, 48 60-inch
                                                                         piles.
                                                                         Anchor handling
                                                                         for pipeline installation.
2023--Season 5.................  Hilcorp/Harvest......................   Pipeline           MCI
                                                                         maintenance (geohazard,
                                                                         water jet, grinder).
----------------------------------------------------------------------------------------------------------------
LCI = Lower Cook Inlet, MCI = Middle Cook Inlet Wells, NCI = North Cook Inlet Unit, TB = Trading Bay, PLF =
  Product Loading Facility, TMOF = Temporary Material Offloading Facility, MMOF = Mainline Material Offloading
  Facility, VSP = Vertical Seismic Profiling.


                        Table 12--Estimates of Total Number of Takes by Level B Harassment and Number of Sea Otters Taken by Year
                                                                   [or project season]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           2019 (Season    2020 (Season    2021 (Season    2022 (Season    2023 (Season
                                                                1)              2)              3)              4)              5)             Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Takes by year (season)..................................          903.98            5.80          751.34            1.48            0.00        1,662.60
% takes by year (season)................................              54               0              45               0               0  ..............
No. of otters taken.....................................           16.65            0.89           75.28            0.23            0.00           93.12
% otters taken by year (season).........................              18               1              81               0               0  ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------

Critical Assumptions

    In order to conduct this analysis and estimate the potential amount 
of take, several critical assumptions were made. Here we discuss these 
assumptions, the potential sources of bias or error inherent in them, 
and their effects on the analysis. Take by harassment is equated herein 
with exposure to noise meeting or exceeding the specified criteria. We 
assume all otters exposed to these noise levels will exhibit behavioral 
responses that indicate harassment or disturbance. There are likely to 
be a proportion of animals that respond in ways that indicate some 
level of disturbance but do not experience significant biological 
consequences. 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 net effect is 
unknown.
    Our estimates do not account for variable responses by age and sex. 
Females with dependent pups and with pups that have recently weaned are 
physiologically the most sensitive (Thometz et al. 2014) and most 
likely to experience take from disturbance. There is not enough 
information on composition of the Cook Inlet sea otter population in 
the applicant's project area to incorporate individual variability 
based on age and sex or to predict its influence on take estimates. We 
therefore assume the response rates are uniform throughout the 
population. The degree of over- or under-estimation of take is unknown.
    The estimates of behavioral response presented here do not account 
for the individual movements of animals away from the project area due 
to avoidance or habituation. Our assessment assumes animals remain 
stationary; i.e., density does not change. There is not enough 
information about the movement of sea otters in response to specific 
disturbances to refine these assumptions. For instance, on average, a 
single otter is expected to experience 18 instances of Level B take and 
another otter will experience 3 instances of Level A take. While otters 
do have restricted movements and smaller home ranges than other marine 
mammals and, therefore, are likely to be exposed to sound during 
multiple days of work, it is unlikely that any single otter will

[[Page 10243]]

continue to respond in the same manner. The otter will either depart 
from the area and return after activities are complete, or it will 
habituate to the disturbance and will no longer experience take. 
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. (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 avoiding some level of take. However, additional 
information is needed to quantify the effectiveness of mitigation. The 
monitoring and reporting in this proposed ITR 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 takes 
that will be avoided by applying effective mitigation measures. This 
scenario leads to overestimation in calculation of take.
    The current project description represents the applicant's best 
expectation of how, where, and when work will proceed. We expect that 
the current project description is an accurate depiction of the work 
that will be conducted. Details provided in future applications for 
LOAs under these proposed regulations must provide accurate project 
details, which may include minor changes from those described here. 
Minor changes to the details of the proposed activities, such as a 
change of the specific vessels or a change in the start date of a 
specific activity, are not expected to change the overall estimates of 
take. In all cases, the most accurate information about the project and 
the specific estimation parameters will be used, along with methods 
that are consistent with those described here, to calculate the effects 
of the activities and to ensure that the effects remain concordant with 
the determinations of this proposed rulemaking. Larger project changes 
that will alter the findings proposed here will not be considered as 
part of this proposed ITR.

Potential Impacts on Sea Otter Stocks

    The estimated number of takes by Level B harassment is 1,663 
instances of take of 93 otters due to behavioral responses or TTS 
associated with noise exposure. Among otters from the southwest stock, 
410 Level B takes of 9 otters are expected; and among the southcentral 
stock, 1,253 takes of 84 otters from Level B harassment are expected. 
The estimated number of takes by Level A harassment is three instances 
of take of a single otter due to behavioral responses or PTS associated 
with noise exposure. This otter and is expected to belong to the 
southcentral stock. Combined, the expected number of Level A and Level 
B takes is 410 takes of 9 otters from the southwest stock and 1,256 
takes of 85 otters from the southcentral stock.
    These levels represent a small proportion relative to the most 
recent stock abundance estimates for the sea otter. Take of 9 animals 
is 0.02 percent of the best available estimate of the current 
population size of 45,064 animals in the southwest stock (USFWS 2014a) 
(9/45,064 [ap] 0.0002). Take of 85 is about 0.5 percent of the 18,297 
animals in the southcentral stock (USFWS 2014b) (85/18,297 [ap] 
0.00465).
    Sea otters exposed to sound produced by the project are likely to 
respond with temporary behavioral modification or displacement. Project 
activities could temporarily interrupt the feeding, resting, and 
movement of sea otters. Because activities will occur during a limited 
amount of time and in a localized region, the impacts associated with 
the project are likewise temporary and localized. The anticipated 
effects are primarily short-term behavioral reactions and displacement 
of sea otters near active operations.
    Animals that encounter the proposed activities may exert more 
energy than they would otherwise due to temporary cessation of feeding, 
increased vigilance, and retreat from the project area. We expect that 
affected sea otters would tolerate this exertion without measurable 
effects on health or reproduction. Most of the anticipated takes would 
be due to short-term Level B harassment in the form of TTS, startling 
reactions, or temporary displacement. Three instances of Level A take 
are expected to occur due to PTS. The effects of PTS in sea otters are 
unknown.
    With the adoption of the measures proposed in the applicant's 
mitigation and monitoring plan and required by this proposed ITR, the 
amount and likelihood of Level A and Level B take will be reduced. The 
number of otters affected will be small relative to the stocks, and the 
overall effect on the stocks is expected to be negligible.

Potential Impacts on Subsistence Uses

    The proposed activities will occur near marine subsistence harvest 
areas used by Alaska Natives from the villages of Ninilchik, Salamatof, 
Tyonek, Nanwalek, Seldovia, and Port Graham. Between 2013 and 2018, 
approximately 491 sea otters were harvested for subsistence use from 
Cook Inlet, averaging 98 per year. The large majority were taken in 
Kachemak Bay. Harvest occurs year-round, but peaks in April and May, 
with about 40 percent of the total taken at that time. February and 
March are also high harvest periods, with about 10 percent of the total 
annual harvest occurring in each of those months. The proposed project 
area will avoid Kachemak Bay and therefore avoid significant overlap 
with subsistence harvest areas. The applicant's activities will not 
preclude access to hunting areas or interfere in any way with 
individuals wishing to hunt. Vessels, aircraft, and project noise 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 applicant will coordinate with Alaska Native villages and 
Tribal organizations to identify and avoid potential conflicts. If any 
conflicts are identified, the applicant will develop a POC specifying 
the particular steps that will be taken to address any effects the 
project might have on subsistence harvest.

Findings

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 proposed project may result in 
approximately 1,666 takes of 94 otters, of which, 410 takes of 9

[[Page 10244]]

animals will be from the southwest stock and 1,256 takes of 85 otters 
will be from the southcentral stock. These numbers represent less than 
1 percent of each stock (USFWS 2014a,b). Based on these numbers, we 
propose a finding that the applicant's proposed activities will take, 
by harassment, only a small number of animals.

Negligible Impact

    We propose a finding that any 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 species or 
stocks. 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 material supplied by the applicant, other operators in Alaska, 
our files and datasets, published reference materials, and species 
experts.
    Sea 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 most affected animals. Most animals will respond to disturbance by 
moving away from the source, which may cause temporary interruption of 
foraging, resting, or other natural behaviors. Affected animals are 
expected to resume normal behaviors soon after exposure, with no 
lasting consequences. Some animals may exhibit more severe responses 
typical of Level B harassment, such as fleeing, ceasing feeding, or 
flushing from a haulout. These responses could have significant 
biological impacts for affected individuals. One otter may experience 
Level A take from PTS. The effects to this individual are unknown, but 
lasting effects to survival and reproduction for this individual are 
possible. Thus, although the proposed activities may result in 
approximately 410 takes of 9 animals from the southwest stock and 1,256 
takes of 85 otters from the southcentral stock, we do not expect this 
level of harassment to affect annual rates of recruitment or survival 
or result in adverse effects on the species or stocks.
    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 applicant's 
mitigation and monitoring plan. Minimum flight altitudes will help 
operators avoid take from exposure to aircraft noise. Protected species 
observers and procedures implemented by PSOs will limit Level A take 
during seismic work and pile driving. Collision-avoidance measures, 
including speed reductions when otters are present, will ensure that 
boat strikes are unlikely. These mitigation measures are designed to 
minimize interactions with and impacts to sea otters and, together with 
the monitoring and reporting procedures, are required for the validity 
of our finding and are a necessary component of the proposed ITR. For 
these reasons, we propose a finding that the proposed activities will 
have a negligible impact on sea otters.

Impact on Subsistence

    We propose a finding that the anticipated harassment caused by the 
applicant's 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 timing and location of subsistence harvest 
activities in the area of the proposed project. We also considered the 
applicant's consultation with subsistence communities, proposed 
measures for avoiding impacts to subsistence harvest, and commitment to 
development of a POC, should any adverse impacts be identified.

Request for Public Comments

    If you wish to comment on this proposed regulation, the associated 
draft environmental assessment, or the information collection, you may 
submit your comments by any of the methods described in ADDRESSES. 
Please identify if you are commenting on the proposed regulation, draft 
environmental assessment, or the information collection, make your 
comments as specific as possible, confine them to issues pertinent to 
the proposed regulation, 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 by the close of the comment period (see 
DATES).
    Comments, including names and street addresses of respondents, will 
become part of the administrative record. 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.

Required Determinations

National Environmental Policy Act (NEPA)

    We have prepared a draft environmental assessment (EA) in 
accordance with the NEPA (42 U.S.C. 4321 et seq.). We have 
preliminarily concluded that issuance of an incidental take regulation 
for the nonlethal, incidental, unintentional take by harassment of 
small numbers of sea otters in Alaska during activities conducted by 
Hilcorp, Harvest, and AGDC in 2019 to 2024 would not significantly 
affect the quality of the human environment and that the preparation of 
an environmental impact statement is not required by section 102(2) of 
NEPA or its implementing regulations. A copy of the EA can be obtained 
from the locations described in ADDRESSES.

Endangered Species Act (ESA)

    Under the ESA, all Federal agencies are required to ensure the 
actions they authorize are not likely to jeopardize the continued 
existence of any threatened or endangered species or result in 
destruction or adverse modification of critical habitat. The southwest 
DPS of sea otters is listed as threatened under the ESA at 50 CFR 
17.11(h) (70 FR 46366, August 9, 2005). The proposed activities will 
occur within designated critical habitat found at 50 CFR 17.95(a). 
Prior to issuance of a final ITR, if warranted, the Service will 
complete intra-Service consultation under section 7 of the ESA on our 
proposed issuance of an ITR, which will consider whether the effects of 
the proposed project will adversely affect sea otters or adversely 
modify their critical habitat. These evaluations and findings will be 
made available on the Service's website and at https://www.regulations.gov.

Regulatory Planning and Review

    Executive Order 12866 provides that the Office of Information and 
Regulatory Affairs (OIRA) in the Office of Management and Budget will 
review all significant rules. OIRA has determined that this rule is not 
significant.

[[Page 10245]]

    Executive Order 13563 reaffirms the principles of Executive Order 
12866 while calling for improvements in the nation's regulatory system 
to promote predictability, to reduce uncertainty, and to use the best, 
most innovative, and least burdensome tools for achieving regulatory 
ends. The executive order directs agencies to consider regulatory 
approaches that reduce burdens and maintain flexibility and freedom of 
choice for the public where these approaches are relevant, feasible, 
and consistent with regulatory objectives. Executive Order 13563 
emphasizes further that regulations must be based on the best available 
science and that the rulemaking process must allow for public 
participation and an open exchange of ideas. We have developed this 
rule in a manner consistent with these requirements.
    OIRA bases its determination upon the following four criteria: (a) 
Whether the rule will have an annual effect of $100 million or more on 
the economy or adversely affect an economic sector, productivity, jobs, 
the environment, or other units of the government; (b) Whether the rule 
will create inconsistencies with other Federal agencies' actions; (c) 
Whether the rule will materially affect entitlements, grants, user 
fees, loan programs, or the rights and obligations of their recipients; 
(d) Whether the rule raises novel legal or policy issues.
    Expenses will be related to, but not necessarily limited to: The 
development of applications for LOAs; monitoring, recordkeeping, and 
reporting activities conducted during oil and gas operations; 
development of activity- and species-specific marine mammal monitoring 
and mitigation plans; and coordination with Alaska Natives to minimize 
effects of operations on subsistence hunting. Realistically, costs of 
compliance with this proposed rule are minimal in comparison to those 
related to actual oil and gas exploration, development, production, and 
transport operations. The actual costs to develop the petition for 
promulgation of regulations and LOA requests probably do not exceed 
$200,000 per year, short of the ``major rule'' threshold that would 
require preparation of a regulatory impact analysis. As is presently 
the case, profits will accrue to the applicant; royalties and taxes 
will accrue to the Government; and the rule will have little or no 
impact on decisions by the applicant to relinquish tracts and write off 
bonus payments.

Small Business Regulatory Enforcement Fairness Act

    We have determined that this rule is not a major rule under 5 
U.S.C. 804(2), the Small Business Regulatory Enforcement Fairness Act. 
The rule is also not likely to result in a major increase in costs or 
prices for consumers, individual industries, or government agencies or 
have significant adverse effects on competition, employment, 
productivity, innovation, or on the ability of United States-based 
enterprises to compete with foreign-based enterprises in domestic or 
export markets.

Regulatory Flexibility Act

    We have also determined that this rule will not have a significant 
economic effect on a substantial number of small entities under the 
Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Companies and their 
contractors conducting exploration, development, production, and 
transportation of oil and gas in Alaska have been identified as the 
only likely applicants under the regulations, and these potential 
applicants have not been identified as small businesses. Therefore, 
neither a Regulatory Flexibility Analysis nor a Small Entity Compliance 
Guide is required.

Takings Implications

    This rule does not have takings implications under Executive Order 
12630 because it authorizes the nonlethal, incidental, but not 
intentional, take of sea otters by oil and gas industry companies and, 
thereby, exempts these companies from civil and criminal liability as 
long as they operate in compliance with the terms of their LOAs. 
Therefore, a takings implications assessment is not required.

Federalism Effects

    This rule does not contain policies with Federalism implications 
sufficient to warrant preparation of a Federalism Assessment under 
Executive Order 13132. The MMPA gives the Service the authority and 
responsibility to protect sea otters.

Unfunded Mandates Reform Act

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.), this rule will not ``significantly or uniquely'' affect small 
governments. A Small Government Agency Plan is not required. The 
Service has determined and certifies pursuant to the Unfunded Mandates 
Reform Act that this rulemaking will not impose a cost of $100 million 
or more in any given year on local or State governments or private 
entities. This rule will not produce a Federal mandate of $100 million 
or greater in any year, i.e., it is not a ``significant regulatory 
action'' under the Unfunded Mandates Reform Act.

Government-to-Government Relationship With Native American Tribal 
Governments

    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 
ITR process identified in the MMPA, the applicant has 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 applicant has engaged these groups in informational communications. 
We invite continued discussion about the proposed ITR.

Civil Justice Reform

    The Departmental Solicitor's Office has determined that this 
regulation does not unduly burden the judicial system and meets the 
applicable standards provided in sections 3(a) and 3(b)(2) of Executive 
Order 12988.

Paperwork Reduction Act

    This rule requests a revision to an existing information 
collection. All information collections require approval under the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). We may not 
conduct or sponsor, and you are not required to respond to, a 
collection of information unless it displays a

[[Page 10246]]

currently valid OMB control number. The OMB previously reviewed and 
approved the information collection requirements associated with 
incidental take of marine mammals in the Beaufort and Chukchi Seas and 
assigned OMB Control Number 1018-0070 (expires July 31, 2020).
    The revised requirements reporting and/or recordkeeping 
requirements identified below require approval by OMB:
    (1) Remove references to 50 CFR part 18, subpart I (expired); and
    (2) Add references to 50 CFR part 18, subpart K.
    Title of Collection: Incidental Take of Marine Mammals During 
Specified Activities, 50 CFR 18.27 and 50 CFR 18, Subparts J and K.
    OMB Control Number: 1018-0070.
    Form Numbers: None.
    Type of Review: Revision of a currently approved collection.
    Respondents/Affected Public: Oil and gas industry representatives, 
including applicants for ITRs and LOAs, operations managers, and 
environmental compliance personnel.
    Total Estimated Number of Annual Respondents: 84.
    Total Estimated Number of Annual Responses: 356.
    Estimated Completion Time per Response: Varies from 1.5 hours to 
150 hours, depending on activity.
    Total Estimated Number of Annual Burden Hours: 1,800.
    Respondent's Obligation: Required to obtain or retain a benefit.
    Frequency of Collection: On occasion.
    Total Estimated Annual Nonhour Burden Cost: $200,000.
    As part of our continuing effort to reduce paperwork and respondent 
burdens, we invite the public and other Federal agencies to comment on 
any aspect of this information collection, including:
    (1) Whether or not the collection of information is necessary, 
including whether or not the information will have practical utility;
    (2) The accuracy of our estimate of the burden for this collection 
of information;
    (3) Ways to enhance the quality, utility, and clarity of the 
information to be collected; and
    (4) Ways to minimize the burden of the collection of information on 
respondents.
    Send your comments and suggestions on this information collection 
by the date indicated in DATES to the Desk Officer for the Department 
of the Interior at OMB-OIRA at (202) 395-5806 (fax) or 
[email protected] (email). You may view the information 
collection request(s) at http://www.reginfo.gov/public/do/PRAMain. 
Please provide a copy of your comments to the Service Information 
Collection Clearance Officer, U.S. Fish and Wildlife Service, 5275 
Leesburg Pike, MS: BPHC, Falls Church, VA 22041-3803 (mail); or 
[email protected] (email). Please reference OMB Control Number 1018-
0070 in the subject line of your comments.

Energy Effects

    Executive Order 13211 requires agencies to prepare Statements of 
Energy Effects when undertaking certain actions. This rule provides 
exceptions from the taking prohibitions of the MMPA for entities 
engaged in the exploration of oil and gas in Cook Inlet, Alaska. By 
providing certainty regarding compliance with the MMPA, this rule will 
have a positive effect on the oil and gas industry and its activities. 
Although the rule requires applicants to take a number of actions, 
these actions have been undertaken as part of oil and gas industry 
operations for many years as part of similar past regulations in 
Alaska. Therefore, this rule is not expected to significantly affect 
energy supplies, distribution, or use and does not constitute a 
significant energy action. No Statement of Energy Effects is required.

References

    For a list of the references cited in this proposed rule, see 
Docket No. FWS-R7-ES-2019-0012, available at https://www.regulations.gov.

List of Subjects in 50 CFR Part 18

    Administrative practice and procedure, Alaska, Imports, Indians, 
Marine mammals, Oil and gas exploration, Reporting and recordkeeping 
requirements, Transportation.

Proposed Regulation Promulgation

    For the reasons set forth in the preamble, the Service proposes to 
amend part 18, subchapter B of chapter 1, title 50 of the Code of 
Federal Regulations as set forth below.

PART 18--MARINE MAMMALS

0
1. The authority citation of 50 CFR part 18 continues to read as 
follows:

    Authority: 16 U.S.C. 1361 et seq.

0
2. Add subpart K to read as follows:

Subpart K--Nonlethal Taking of Marine Mammals Incidental to Oil and 
Gas Activities in Cook Inlet, Alaska

Sec.
18.130 Specified activities covered by this subpart.
18.131 Specified geographic region where this subpart applies.
18.132 Dates this subpart is in effect.
18.133 Authorized take allowed under a Letter of Authorization 
(LOA).
18.134 Procedure to obtain a Letter of Authorization (LOA).
18.135 How the Service will evaluate a request for a Letter of 
Authorization (LOA).
18.136 Prohibited take under a Letter of Authorization (LOA).
18.137 Mitigation.
18.138 Monitoring.
18.139 Reporting requirements.
18.140 Measures to reduce impacts to subsistence users.
18.141 Information collection requirements.


Sec.  18.130   Specified activities covered by this subpart.

    Regulations in this subpart apply to the nonlethal incidental, but 
not intentional, take, as defined in Sec.  18.3 and under section 3 of 
the Marine Mammal Protection Act (16 U.S.C. 1371 et seq.), of small 
numbers of northern sea otters (Enhydra lutris kenyoni; hereafter 
``otter,'' ``otters,'' or ``sea otters'') by Hilcorp Alaska, LLC, 
Harvest Alaska, LLC, and the Alaska Gasline Development Corporation 
while engaged in activities associated with or in support of oil and 
gas exploration, development, production, and transportation in Cook 
Inlet, Alaska.


Sec.  18.131   Specified geographic region where this subpart applies.

    (a) The specified geographic region is Cook Inlet, Alaska, south of 
a line from the Susitna River Delta to Point Possession (approximately 
61[deg]15'54'' N, 150[deg]41'07'' W, to 61[deg]02'19'' N, 
150[deg]23'48'' W, WGS 1984) and north of a line from Rocky Cove to 
Coal Cove (approximately 59[deg]25'56'' N, 153[deg]44'25'' W and 
59[deg]23'48'' N, 151[deg]54'28'' W, WGS 1984), excluding Ursus Cove, 
Iniskin Bay, Iliamna Bay, and Tuxedni Bay.
    (b) The geographic area of these incidental take regulations (ITRs) 
includes all Alaska State waters and Outer Continental Shelf Federal 
waters within this area as well as all adjacent rivers, estuaries, and 
coastal lands where sea otters may occur, except for those areas 
explicitly excluded in paragraph (a) of this section.
    (c) Map of the Cook Inlet ITR region follows:

[[Page 10247]]

[GRAPHIC] [TIFF OMITTED] TP19MR19.000

Sec.  18.132   Dates this subpart is in effect.

    Regulations in this subpart are effective from [EFFECTIVE DATE OF 
THE FINAL RULE] to [DATE 5 YEARS AFTER THE EFFECTIVE DATE OF THE FINAL 
RULE].


Sec.  18.133   Authorized take allowed under a Letter of Authorization 
(LOA).

    (a) To incidentally take marine mammals pursuant to this subpart, 
Hilcorp Alaska, LLC, Harvest Alaska, LLC, or the Alaska Gasline 
Development Corporation (hereafter ``the applicant'') must apply for 
and obtain an LOA in accordance with Sec. Sec.  18.27(f) and 18.134.
    (b) An LOA allows for the nonlethal, incidental, but not 
intentional take by harassment of sea otters during activities 
specified in Sec.  18.130 within the Cook Inlet ITR region described in 
Sec.  18.131.
    (c) Each LOA will set forth:
    (1) Permissible methods of incidental take;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (d) Issuance of the LOA(s) must be based on a determination that 
the level of take will be consistent with the findings made for the 
total allowable take under this subpart.


Sec.  18.134   Procedure to obtain a Letter of Authorization (LOA).

    (a) The applicant must be a U.S. citizen as defined in Sec.  
18.27(c) and must submit the request for authorization to the U.S. Fish 
and Wildlife Service (Service) Alaska Region Marine Mammals Management 
Office (MMM), MS 341, 1011 East Tudor Road, Anchorage, Alaska 99503, at 
least 90 days prior to the start of the proposed activity.
    (b) The request for an LOA must comply with the requirements set 
forth in Sec. Sec.  18.137 through 18.139 and must include the 
following information:
    (1) A plan of operations that describes in detail the proposed 
activity (type of project, methods, and types and numbers of equipment 
and personnel, etc.), the dates and duration of the activity, and the 
specific locations of and areas affected by the activity. Changes to 
the proposed project without prior authorization may invalidate an LOA.
    (2) A site-specific marine mammal monitoring and mitigation plan to 
monitor and mitigate the effects of the activity on sea otters.
    (3) An assessment of potential effects of the proposed activity on 
subsistence hunting of sea otters.
    (i) The applicant must communicate with potentially affected 
subsistence communities along the Cook Inlet coast and appropriate 
subsistence user organizations to discuss the location, timing, and 
methods of proposed activities and identify any potential conflicts 
with subsistence hunting activities.
    (ii) The applicant must specifically inquire of relevant 
communities and organizations if the proposed activity will interfere 
with the availability of sea otters for the subsistence use of those 
groups.
    (iii) The applicant must include documentation of consultations 
with potentially affected user groups. Documentation must include a 
list of

[[Page 10248]]

persons contacted, a summary of any concerns identified by community 
members and hunter organizations, and the applicant's responses to 
identified concerns.
    (iv) If any concerns regarding effects of the activity on sea otter 
subsistence harvest are identified, the applicant will provide to the 
Service a Plan of Cooperation (POC) with specific steps for addressing 
those concerns.


Sec.  18.135   How the Service will evaluate a request for a Letter of 
Authorization (LOA).

    (a) The Service will evaluate each request for an LOA based on the 
specific activity and the specific geographic location. We will 
determine whether the level of activity identified in the request is 
commensurate with the analysis and findings made for this subpart 
regarding the number of animals likely to be taken and evaluate whether 
there will be a negligible impact on sea otters or an adverse impact on 
the availability of sea otters for subsistence uses. Depending on the 
results of the evaluation, we may grant the authorization, add further 
conditions, or deny the authorization.
    (b) Once issued, the Service may withdraw or suspend an LOA if the 
project activity is modified in a way that undermines the results of 
the previous evaluation, if the conditions of the regulations in this 
subpart are not being substantially complied with, or if the taking 
allowed is or may be having more than a negligible impact on the 
affected stock of sea otters or an unmitigable adverse impact on the 
availability of sea otters for subsistence uses.
    (c) The Service will make decisions concerning withdrawals of an 
LOA, either on an individual or class basis, only after notice and 
opportunity for public comment in accordance with Sec.  18.27(f)(5). 
The requirement for notice and public comment will not apply should we 
determine that an emergency exists that poses a significant risk to the 
well-being of the species or stocks of sea otters.


Sec.  18.136   Prohibited take under a Letter of Authorization (LOA).

    (a) Except as otherwise provided in this subpart, prohibited taking 
is described in Sec.  18.11 as well as: Intentional take, lethal 
incidental take of sea otters, and any take that fails to comply with 
this subpart or with the terms and conditions of an LOA.
    (b) If project activities cause unauthorized take, the applicant 
must take the following actions:
    (1) Cease activities immediately (or reduce activities to the 
minimum level necessary to maintain safety) and report the details of 
the incident to the Service MMM within 48 hours; and
    (2) 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.


Sec.  18.137   Mitigation.

    (a) Mitigation measures for all LOAs. The applicant, including all 
personnel operating under the applicant's authority (or ``operators,'' 
including contractors, subcontractors, and representatives) must 
undertake the following activities to avoid and minimize take of sea 
otters by harassment.
    (1) Implement policies and procedures to avoid interactions with 
and minimize to the greatest extent practicable adverse impacts on sea 
otters, their habitat, and the availability of these marine mammals for 
subsistence uses.
    (2) Develop avoidance and minimization policies and procedures, in 
cooperation with the Service, that include temporal or spatial activity 
restrictions to be used in response to the presence of sea otters 
engaged in a biologically significant activity (e.g., resting, feeding, 
hauling out, mating, or nursing).
    (3) Cooperate with the Service's MMM Office and other designated 
Federal, State, and local agencies to monitor and mitigate the impacts 
of oil and gas industry activities on sea otters.
    (4) Allow Service personnel or the Service's designated 
representative to board project vessels or visit project work sites for 
the purpose of monitoring 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.
    (5) Designate trained and qualified protected species observers 
(PSOs) to monitor for the presence of sea otters, initiate mitigation 
measures, and monitor, record, and report the effects of the activities 
on sea otters. The applicant is responsible for providing training to 
PSOs to carry out mitigation and monitoring.
    (6) Have an approved mitigation and monitoring plan on file with 
the Service MMM and onsite that includes the following information:
    (i) The type of activity and where and when the activity will occur 
(i.e., a summary of the plan of operation);
    (ii) Personnel training policies, procedures, and materials;
    (iii) Site-specific sea otter interaction risk evaluation and 
mitigation measures;
    (iv) Sea otter avoidance and encounter procedures; and
    (v) Sea otter observation and reporting procedures.
    (7) Contact affected subsistence communities and hunter 
organizations to identify any potential conflicts that may be caused by 
the proposed activities and provide the Service documentation of 
communications as described in Sec.  18.134.
    (b) Mitigation measures for in-water noise-generating work. The 
applicant must carry out the following measures:
    (1) Mitigation zones. Establish mitigation zones for project 
activities that generate underwater sound levels >=160 decibels (dB) 
between 125 hertz (Hz) and 38 kilohertz (kHz) (hereafter ``noise-
generating work'').
    (i) All dB levels are referenced to 1 [micro]Pa for underwater 
sound. All dB levels herein are dBRMS unless otherwise 
noted; dBRMS refers to the root-mean-squared dB level, the 
square root of the average of the squared sound pressure level, 
typically measured over 1 second.
    (ii) Mitigation zones must include all in-water areas where work-
related sound received by sea otters will match the levels and 
frequencies in paragraph (b)(1) of this section. Mitigation zones will 
be designated as follows:
    (A) An Exclusion Zone (EZ) will be established throughout all areas 
where sea otters may be exposed to sound levels capable of causing 
Level A take as shown in the table in paragraph (b)(1)(iii) of this 
section.
    (B) The Safety Zone (SZ) is an area larger than the EZ and will 
include all areas within which sea otters may be exposed to noise 
levels that will likely result in Level B take as shown in the table in 
paragraph (b)(1)(iii) of this section.
    (C) Both the EZ and SZ will be centered on the sound source. The 
method of estimation and minimum radius of each zone will be specified 
in any LOA issued under Sec.  18.135 and will be based on the best 
available science.
    (iii) Summary of acoustic exposure thresholds for take of sea 
otters from underwater sound in the frequency range 125 Hz-32 kHz:

[[Page 10249]]



----------------------------------------------------------------------------------------------------------------
                                        Injury (Level A) threshold \1\         Disturbance (Level B) threshold
          Marine mammals          ------------------------------------------------------------------------------
                                        Impulsive          Non-impulsive                     All
----------------------------------------------------------------------------------------------------------------
Sea otters.......................  232 dB peak; 203;    219 dB SELcum......  160 dBRMS.
                                    dB SELcum.
----------------------------------------------------------------------------------------------------------------
\1\ Based on acoustic criteria for otariid pinnipeds from the National Marine Fisheries Service. Sound source
  types are separated into impulsive (e.g., seismic, pipe driving, sub-bottom profiler) and non-impulsive (tugs,
  towing rigs, drilling, water jet, hydraulic grinder) and require estimation of the distance to the peak
  received sound pressure level (peak) and 24-hr cumulative sound exposure level (SELcum).

    (2) Monitoring. Designate trained and qualified PSOs or 
``observers'' to monitor for the presence of sea otters in mitigation 
zones, initiate mitigation measures, and record and report the effects 
of project work on otters for all noise-generating work.
    (3) Mitigation measures for sea otters in mitigation zones. The 
following actions will be taken in response to otters in mitigation 
zones:
    (i) Sea otters that are under no visible distress within the SZ 
must be monitored continuously. Power down, shut down, or maneuver away 
from the sea otter if practicable to reduce sound received by the 
animal. Maintain 100 m (301 ft) separation distance whenever possible. 
Exposures in this zone are counted as one Level B take per animal per 
day.
    (ii) When sea otters are observed within or approaching the EZ, 
noise-generating work as defined in paragraph (b)(1) of this section 
must be immediately shut down or powered down to reduce the size of the 
zone sufficiently to exclude the animal from the zone. Vessel speed or 
course may be altered to achieve the same task. Exposures in this zone 
are counted as one Level A take per animal per day.
    (iii) When sea otters are observed in visible distress (for 
example, vocalizing, repeatedly spy-hopping, or fleeing), noise-
generating work as defined in paragraph (b)(1) of this section must be 
immediately shut down or powered down to reduce the size of the zone 
sufficiently to exclude the animal from the zone.
    (iv) Following a shutdown, the noise-generating activity will not 
resume until the sea otter has cleared the EZ. The animal will be 
considered to have cleared the EZ if it is visually observed to have 
left the EZ or has not been seen within the EZ for 30 minutes or 
longer.
    (4) Ramp-up procedures. Prior to noise-generating work, a ``ramp-
up'' procedure must be used to increase the levels of underwater sound 
from noise-generating work at a gradual rate.
    (i) Seismic surveys. A ramp-up will be used at the initial start of 
airgun operations and prior to restarting after any period greater than 
10 minutes without airgun operations, including a power-down or 
shutdown event (described in paragraphs (b)(6) and (7) of this 
section). During geophysical work, the number and total volume of 
airguns will be increased incrementally until the full volume is 
achieved. The rate of ramp-up will be no more than 6 dB per 5-minute 
period. Ramp-up will begin with the smallest gun in the array that is 
being used for all airgun array configurations. During the ramp-up, the 
applicable mitigation zones (based on type of airgun and sound levels 
produced) must be maintained. If the complete applicable EZ has not 
been visible for at least 30 minutes prior to the start of operations, 
ramp-up will not start unless a 10-in\3\ mitigation gun has been 
operating during the interruption of seismic survey operations. It will 
not be permissible to ramp up from a complete shutdown in thick fog or 
at other times when the outer part of the applicable EZ is not visible, 
unless the mitigation gun has been operating.
    (ii) Pile/pipe driving. A ramp-up of the hammering will precede 
each day's pipe/pile driving activities or if pipe/pile driving has 
ceased for more than 1 hour. The EZ will be cleared 30 minutes prior to 
a ramp-up to ensure no sea otters are within or entering the EZ. 
Initial hammering starts will not begin during periods of poor 
visibility (e.g., night, fog, wind) when the entire EZ is not visible. 
The ramp-up procedure involves initially starting with three soft 
strikes at 40 percent energy, followed by a 1-minute waiting period 
followed by two subsequent three-strike sets. Monitoring will occur 
during all hammering sessions.
    (iii) All activities. Any shutdown due to sea otters sighted within 
the EZ must be followed by a 30-minute all-clear period and then a 
standard full ramp-up. Any shutdown for other reasons resulting in the 
cessation of the sound source for a period greater than 30 minutes must 
also be followed by full ramp-up procedures. If otters are observed 
during a ramp-up effort or prior to startup, a PSO must record the 
observation and monitor the animal's position until it moves out of 
visual range. Noise-generating work may commence if, after a full and 
gradual effort to ramp up the underwater sound level, the otter is 
outside of the EZ and does not show signs of visible distress (for 
example, vocalizing, repeatedly spy-hopping, or fleeing).
    (5) Startup procedures. (i) Visual monitoring must begin at least 
30 minutes prior to, and continue throughout, ramp-up efforts.
    (ii) Visual monitoring must continue during all noise-generating 
work occurring in daylight hours.
    (6) Power-down procedures. A power-down procedure involves reducing 
the volume of underwater sound generated to prevent an otter from 
entering the EZ.
    (i) Whenever a sea otter is detected outside the EZ and, based on 
its position and motion relative to the noise-generating work, appears 
likely to enter the EZ but has not yet done so, operators may reduce 
power to noise-generating equipment as an alternative to a shutdown.
    (ii) Whenever a sea otter is detected in the SZ, an operator may 
power down when practicable to reduce Level B take.
    (iii) During a power-down of seismic work, the number of airguns in 
use may be reduced, such that the EZ is reduced, making the sea otters 
unlikely to enter the EZ. A mitigation airgun (airgun of small volume 
such as the 10-in\3\ gun) will be operated continuously during a power-
down of seismic work.
    (iv) After a power down, noise-generating work will not resume 
until the sea otter has cleared the applicable EZ. The animal will be 
considered to have cleared the applicable zone if it is visually 
observed to have left the EZ and has not been seen within the zone for 
30 minutes.
    (7) Shutdown procedure. A shutdown occurs when all noise-generating 
work is suspended.
    (i) Noise-generating work will be shut down completely if a sea 
otter enters the EZ.
    (ii) The shutdown procedure will be accomplished within several 
seconds of the determination that a sea otter is either in or about to 
enter the EZ.
    (iii) Noise-generating work will not proceed until all sea otters 
have cleared the EZ and the PSOs on duty are confident that no sea 
otters remain within the EZ. An otter will be considered to have 
cleared the EZ if it is visually observed to have left the EZ

[[Page 10250]]

or has not been seen within the zone for 30 minutes.
    (iv) Visual monitoring must continue for 30 minutes after use of 
the acoustic source ceases or the sun sets, whichever is later.
    (8) Emergency shutdown. If observations are made or credible 
reports are received that one or more sea otters are within the area of 
noise-generating work and are indicating acute distress associated with 
the work, such as any injury due to seismic noise or persistent 
vocalizations indicating separation of mother from pup, the work will 
be immediately shut down and the Service contacted. Work will not be 
restarted until review and approval by the Service.
    (c) Mitigation for all in-water construction and demolition 
activity. (1) The applicant must implement a minimum EZ of a 10-m 
radius around the in-water construction and demolition. If a sea otter 
comes within or approaches the EZ, such operations must cease. A larger 
EZ may be required for some activities, such as blasting, and will be 
specified in the LOA.
    (2) All in-water work along the shoreline shall be conducted during 
low tide when the site is dewatered to the maximum extent practicable.
    (d) Measures for vessel-based activities. (1) Vessel operators must 
take every precaution to avoid harassment of sea otters when a vessel 
is operating near these animals.
    (2) Vessels must remain at least 500 m from rafts of otters 
whenever possible.
    (3) Vessels must reduce speed and maintain a distance of 100 m (328 
ft) from all sea otters whenever possible.
    (4) Vessels may not be operated in such a way as to separate 
members of a group of sea otters from other members of the group.
    (5) When weather conditions require, such as when visibility drops, 
vessels must adjust speed accordingly to avoid the likelihood of injury 
to sea otters.
    (6) Vessels in transit and support vessels must use established 
navigation channels or commonly recognized vessel traffic corridors, 
and must avoid alongshore travel in shallow water (<20 m) whenever 
practicable.
    (7) All vessels must avoid areas of active or anticipated 
subsistence hunting for sea otters as determined through community 
consultations.
    (8) Vessel operators must be provided written guidance for avoiding 
collisions and minimizing disturbances to sea otters. Guidance will 
include measures identified in paragraphs (d)(1) through (7) of this 
section.
    (e) Mitigation measures for aircraft activities. (1) Aircraft must 
maintain a minimum altitude of 305 m (1,000 ft) to avoid unnecessary 
harassment of sea otters, except during takeoff and landing, and when a 
lower flight altitude is necessary for safety due to weather or 
restricted visibility.
    (2) Aircraft may not be operated in such a way as to separate 
members of a group of sea otters from other members of the group.
    (3) All aircraft must avoid areas of active or anticipated 
subsistence hunting for sea otters as determined through community 
consultations.


Sec.  18.138   Monitoring.

    (a) Operators shall work with PSOs to apply mitigation measures, 
and shall recognize the authority of PSOs, up to and including stopping 
work, except where doing so poses a significant safety risk to 
personnel.
    (b) Duties of PSOs include watching for and identifying sea otters, 
recording observation details, documenting presence in any applicable 
monitoring zone, identifying and documenting potential harassment, and 
working with operators to implement all appropriate mitigation 
measures.
    (c) A sufficient number of PSOs will be available to meet the 
following criteria: 100 percent monitoring of EZs during all daytime 
periods of underwater noise-generating work; a maximum of 4 consecutive 
hours on watch per PSO; a maximum of approximately 12 hours on watch 
per day per PSO.
    (d) All PSOs will complete a training course designed to 
familiarize individuals with monitoring and data collection procedures. 
A field crew leader with prior experience as a sea otter observer will 
supervise the PSO team. Initially, new or inexperienced PSOs will be 
paired with experienced PSOs so that the quality of marine mammal 
observations and data recording is kept consistent. Resumes for 
candidate PSOs will be made available for the Service to review.
    (e) Observers will be provided with reticule binoculars (10x42), 
big-eye binoculars or spotting scopes (30x), inclinometers, and range 
finders. Field guides, instructional handbooks, maps and a contact list 
will also be made available.
    (f) Observers will collect data using the following procedures:
    (1) All data will be recorded onto a field form or database.
    (2) Global positioning system data, sea state, wind force, and 
weather will be collected at the beginning and end of a monitoring 
period, every hour in between, at the change of an observer, and upon 
sightings of sea otters.
    (3) Observation records of sea otters will include date; time; the 
observer's locations, heading, and speed (if moving); weather; 
visibility; number of animals; group size and composition (adults/
juveniles); and the location of the animals (or distance and direction 
from the observer).
    (4) Observation records will also include initial behaviors of the 
sea otters, descriptions of project activities and underwater sound 
levels being generated, the position of sea otters relative to 
applicable monitoring and mitigation zones, any mitigation measures 
applied, and any apparent reactions to the project activities before 
and after mitigation.
    (5) For all otters in or near a mitigation zone, observers will 
record the distance from the vessel to the sea otter upon initial 
observation, the duration of the encounter, and the distance at last 
observation in order to monitor cumulative sound exposures.
    (6) Observers will note any instances of animals lingering close to 
or traveling with vessels for prolonged periods of time.


Sec.  18.139   Reporting requirements.

    (a) Operators must notify the Service at least 48 hours prior to 
commencement of activities.
    (b) Weekly reports will be submitted to the Service during in-water 
seismic activities. The reports will summarize project activities, 
monitoring efforts conducted by PSOs, the number of sea otters 
detected, the number exposed to sound levels greater than 160 dB, and 
descriptions of all behavioral reactions of sea otters to project 
activities.
    (c) Monthly reports will be submitted to the Service MMM for all 
months during which noise-generating work takes place. The monthly 
report will contain and summarize the following information: Dates, 
times, weather, and sea conditions (including Cook Inlet marine state 
and wind force) when sea otters were sighted; the number, location, 
distance from the sound source, and behavior of the otters; the 
associated project activities; and a description of the implementation 
and effectiveness of mitigation measures with a discussion of any 
specific behaviors the otters exhibited in response to mitigation.
    (d) A final report will be submitted to the Service within 90 days 
after the expiration of each LOA. It will include the following items:
    (1) Summary of monitoring efforts (hours of monitoring, activities 
monitored, number of PSOs, and, if

[[Page 10251]]

requested by the Service, the daily monitoring logs).
    (2) 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, 
and fog and glare) will be discussed.
    (3) The report will also address factors affecting the presence and 
distribution of sea otters (e.g., weather, sea state, and project 
activities). An estimate will be included of the number of sea otters 
exposed to noise at received levels greater than or equal to 160 dB 
(based on visual observation).
    (4) The report will describe changes in sea otter behavior 
resulting from project activities and any specific behaviors of 
interest.
    (5) It will provide a discussion of the mitigation measures 
implemented during project activities and their observed effectiveness 
for minimizing impacts to sea otters. Sea otter observation records 
will be provided to the Service in the form of electronic database or 
spreadsheet files.
    (6) The report will also evaluate the effectiveness of the POC (if 
applicable) for preventing impacts to subsistence users of sea otters, 
and it will assess any effects the operations may have had on the 
availability of sea otters for subsistence harvest.
    (e) All reports shall be submitted by email to 
[email protected].
    (f) Injured, dead, or distressed sea otters that are not associated 
with project activities (e.g., animals known to be from outside the 
project area, previously wounded animals, or carcasses with moderate to 
advanced decomposition or scavenger damage) must be reported to the 
Service within 48 hours of the discovery to either the Service MMM (1-
800-362-5148, business hours); or the Alaska SeaLife Center in Seward 
(1-888-774-7325, 24 hrs.); or both. Photographs, video, location 
information, or any other available documentation shall be provided to 
the Service.
    (g) Operators must notify the Service upon project completion or 
end of the work season.


Sec.  18.140   Measures to reduce impacts to subsistence users.

    (a) Prior to conducting the work, the applicant will take the 
following steps to reduce potential effects on subsistence harvest of 
sea otters:
    (1) Avoid work in areas of known sea otter subsistence harvest;
    (2) Discuss the planned activities with subsistence stakeholders 
including Cook Inlet villages, traditional councils, and the Cook Inlet 
Regional Citizens Advisory Council; and
    (3) Identify and work to resolve concerns of stakeholders regarding 
the project's effects on subsistence hunting of sea otters; and
    (b) If any unresolved or ongoing concerns remain, develop a POC in 
consultation with the Service and subsistence stakeholders to address 
these concerns.


Sec.  18.141   Information collection requirements.

    (a) We may not conduct or sponsor, and a person is not required to 
respond to, a collection of information unless it displays a currently 
valid Office of Management and Budget (OMB) control number. OMB has 
approved the collection of information contained in this subpart and 
assigned OMB control number 1018-0070. You must respond to this 
information collection request to obtain a benefit pursuant to section 
101(a)(5) of the Marine Mammal Protection Act. We will use the 
information to:
    (1) Evaluate the application and determine whether or not to issue 
specific LOAs; and
    (2) Monitor impacts of activities and effectiveness of mitigation 
measures conducted under the LOAs.
    (b) Comments regarding the burden estimate or any other aspect of 
the information collection and recordkeeping requirements in this 
subpart must be submitted to the Information Collection Clearance 
Officer, U.S. Fish and Wildlife Service, at the address listed in 50 
CFR 2.1.

    Dated: March 12, 2019.
Andrea Travnicek,
Principal Deputy Assistant Secretary for Fish and Wildlife and Parks, 
exercising the authority of the Assistant Secretary for Fish and 
Wildlife and Parks.
[FR Doc. 2019-05127 Filed 3-18-19; 8:45 am]
 BILLING CODE 4333-15-P