[Federal Register Volume 84, Number 148 (Thursday, August 1, 2019)]
[Rules and Regulations]
[Pages 37716-37750]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16279]



[[Page 37715]]

Vol. 84

Thursday,

No. 148

August 1, 2019

Part II





 Department of the Interior





-----------------------------------------------------------------------





 Fish and Wildlife Service





50 CFR Part 18





-----------------------------------------------------------------------





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

  Federal Register / Vol. 84 , No. 148 / Thursday, August 1, 2019 / 
Rules and Regulations  

[[Page 37716]]


-----------------------------------------------------------------------

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: Final rule.

-----------------------------------------------------------------------

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, finalize 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 rule authorizes take by 
harassment only; no lethal take is authorized. We will issue Letters of 
Authorization, upon request, for specific proposed activities in 
accordance with these regulations. Additionally, the Office of 
Management and Budget has approved a revision of the existing 
Information Collection control number 1018-0070, for incidental take of 
marine mammals in the Beaufort and Chukchi Seas, to include oil and gas 
activities in Cook Inlet.

DATES: This rule is effective August 1, 2019, and remains effective 
through August 1, 2024.

ADDRESSES: Document availability: You may view this rule, the original 
and updated application packages, supporting information, final 
environmental assessment and U.S. Fish and Wildlife Service finding of 
no significant impact (FONSI), 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.

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 1-
800-362-5148. Persons who use a telecommunications device for the deaf 
(TDD) may call the Federal Relay Service (FRS) at 1-800-877-8339, 24 
hours a day, 7 days a week.
    For information on Information Collection control number 1018-0070, 
contact 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: 

Immediate Promulgation

    In accordance with 5 U.S.C. 553(d)(3), we find that we have good 
cause to make this rule effective less than 30 days after publication. 
Immediate promulgation of the rule will ensure that the applicant will 
implement mitigation measures and monitoring programs in the geographic 
region that reduce the risk of any lethal and nonlethal effects to sea 
otters by their activities.

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 
for non-military readiness activities, 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 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

[[Page 37717]]

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 will require information collection 
activities. The Office of Management and Budget has approved a revision 
of the existing Information Collection control number 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,'' 
unless otherwise indicated) 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. In 
March 2019, Hilcorp and Harvest notified the Service that three-
dimensional (3D) seismic survey activities originally planned to begin 
in April 2019 would be delayed until fall 2019. In June 2019, AGDC, 
Hilcorp, and Harvest also provided an updated application package at 
the request of the Service. The updated application clarified project 
details and provided additional information where necessary to respond 
to questions and concerns raised by comments received during the public 
review of the proposed ITR. These updates and clarifications were minor 
and did not significantly change the analysis of effects or the 
estimates of take, and did not alter the conclusions regarding whether 
the planned activities would have a negligible impact on the stocks, 
would affect subsistence use, or would affect more than a small number 
of animals.

Summary of Changes From the Proposed ITR

    In preparing this final regulation for the incidental take of sea 
otters, we reviewed and considered comments and information from the 
public on our proposed rule published in the Federal Register on March 
19, 2019 (84 FR 10224), for which the comment period was extended by 
notice in the Federal Register on April 5, 2019 (84 FR 13603). We also 
reviewed and considered comments and information from the public for 
our draft Environmental Assessment (EA). Based on those considerations, 
and the new information provided by the applicant, we are finalizing 
these regulations with the following changes from our proposed rule:
     Table 1 and table 3 were updated to reflect the most 
recent project details available from the applicant.
     The Description of Specified Activities and table 1 were 
appended to include redevelopment of existing wells at Granite Point.
     Mitigation measures were added or modified in Sec.  
18.137(b)(1)(ii), (b)(4)(ii), (b)(7)(ii), (b)(9), (c)(2), (c)(3), 
(e)(4), and Sec.  18.140(b) of this final rule.
     The total estimated number of Level B takes was adjusted 
from 1,663 to 1,684 after the analysis was updated to reflect updates 
in the project plans.
     The duration of activities used in the estimation of take 
was adjusted to reflect the maximum number of days during which 
underwater work may generate noise above thresholds for take. The 
following adjustments were made: Vibratory sheet pile driving was 
adjusted from 5 to 20 days, Lower Cook Inlet (LCI) pipe driving was 
revised from 3 to 12 days, Trading Bay (TB) pipe driving was revised 
from 1.5 to 6 days, vertical seismic profiling (VSP) in LCI was changed 
from 2 to 8 days, VSP in TB was adjusted from 1 to 4 days, and use of 
water jets was increased from 10.5 to 21 days.
     The analyses of take tables were updated to remove tugs 
towing rigs and use of hydraulic grinders at the request of the 
applicant and after analysis of take using the updated duration for 
these sources indicated that take was unlikely.
     Field verifications of sound production during two-
dimensional (2D) and 3D seismic surveys have been added to the required 
mitigation measures.
     A discussion of the alternative mitigation measures 
evaluated but not required has been added.
     Use of a mitigation gun was changed from required 
mitigation for 2D and 3D seismic surveys to a measure that may be 
required in LOAs issued under this ITR.
     Table 9 was added to clarify allocation of sea otter take 
by location of activity relative to the appropriate stock boundary.
     Total estimated Level A take was adjusted from three takes 
from the southcentral Alaska stock to one take from the southwest 
Alaska stock and two takes from the southcentral Alaska stock. This 
change was made to correct an error in the proposed ITR.
     A mitigation measure was added requiring an applicant for 
an LOA to evaluate alternatives to pile-supported facilities and 
establishing that the Service may require sound-attenuation devices or 
alternatives to pile-supported designs.
     The Estimated Incidental Take section was updated to 
reflect changes to the analysis due to the updated project details and 
to provide additional clarity in the analysis methods used.
     The evaluation of impacts of the specified activities was 
modified throughout the document to focus on the total numbers of takes 
rather than the numbers of individual sea otters taken. This change was 
needed to ensure the estimates from the analysis were accurate and did 
not underestimate take.

Description of the Regulation

    This regulation does not authorize the specified activities to be 
conducted by the applicant. Rather, it authorizes the nonlethal 
incidental, unintentional take of small numbers of sea otters 
associated with those planned activities based on standards set forth 
in the MMPA. The 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 ITR encompasses 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 (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 Regulation Promulgation, 
Sec.  18.131 Specified geographic region where this subpart applies). 
The 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 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

[[Page 37718]]

marine areas within Cook Inlet: LCI (south of the Forelands to Homer) 
and middle Cook Inlet (MCI; north of the Forelands to the Susitna River 
and Point Possession). Project sites within these general areas include 
TB, Granite Point, and the North Cook Inlet unit (NCI) in the MCI, and 
the Iniskin Peninsula and the OCS waters of LCI.

Description of Specified Activities

    The specified activities (also ``project activities'' or ``planned 
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: 2D and 3D 
seismic surveys in LCI; routine operations of, maintenance of, 
redevelopment of, and production drilling from existing oil and gas 
facilities in MCI; geophysical and geohazard surveys in both regions; 
drilling of two to four exploration wells in OCS waters of LCI and one 
to three wells in MCI; construction of a dock facility in Chinitna Bay; 
and decommissioning of an existing facility at the Drift River Terminal 
in MCI. The following support activities will be conducted: Pipe and 
pile driving using both vibratory and impact hammers; VSP; and pipeline 
and platform maintenance. AGDC plans to install a natural gas pipeline 
from the west side of MCI to the east side of LCI and to construct 
processing and loading facilities on either side. These include a 
product loading facility (PLF) and temporary and mainline materials 
offloading facilities (TMOF, MMOF, MOF). 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 planned work are provided in the applicant's 
updated petition for incidental take regulations for oil and gas 
activities in Cook Inlet (June 2019), 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 Incidental Take Regulation Petition
----------------------------------------------------------------------------------------------------------------
                                                                                                      Total
   Project component name &       Geographic         Year(s)                                       anticipated
           location                 region           planned            Seasonal timing          duration (2019-
                                                                                                      2024)
----------------------------------------------------------------------------------------------------------------
Anchor Point 2D seismic        LCI, Anchor         2021 or 2022  April-October................  30 days (10 days
 survey.                        Point to                                                         in water
                                Kasilof.                                                         seismic).
OCS 3D seismic survey........  LCI OCS.........    2019 or 2020  April-October................  45-60 days.
OCS geohazard survey.........  LCI OCS.........       2019-2021  April-October................  28 days.
OCS exploratory wells........  LCI OCS.........       2020-2022  February-November............  40-60 days per
                                                                                                 well, 2-4 wells
                                                                                                 per year.
Iniskin Peninsula exploration  LCI, west side..       2020-2022  April-October................  180 days.
 and development.
Platform & pipeline            MCI.............       2019-2024  April-October................  180 days per
 maintenance.                                                                                    year.
NCI subsea well geohazard      MCI.............            2020  April-October................  7 days.
 survey.
NCI well abandonment activity  MCI.............            2020  April-October................  90 days.
TB area geohazard survey.....  MCI.............            2020  April-October................  14 days.
Granite Point development      MCI.............            2019  June-October.................  120-150 days.
 drilling.
Drift River terminal           LCI, west side..       2020-2023  April-October................  120 days.
 decommissioning.
Product loading facility pile  MCI.............       2021-2023  April-October................  162 days.
 driving.
Material offloading            MCI.............       2021-2022  April-October................  360 days.
 facilities dredging.
Material offloading            MCI.............       2021-2022  April-October................  482 days.
 facilities pile driving.
Trenching, pipelay, burial...  MCI.............       2023-2024  April-October................  360 days.
Pipelay anchor handling......  MCI.............       2023-2024  April-October................  76 days.
----------------------------------------------------------------------------------------------------------------
LCI = Lower Cook Inlet, MCI = Middle Cook Inlet, NCI = North Cook Inlet, TB = Trading Bay.

Description of Marine Mammals in the Specified Area

    The northern sea otter is 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 Alaska 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 Southwest DPS of sea otters. 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/pages/marine-mammal-management.
    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

[[Page 37719]]

during storms, and they venture farther out during 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/hr (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 seas are calm, and they remain 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 updated petition have the potential to 
result in take of sea otters by harassment from noise. Here we 
characterize ``noise'' as sound released into the environment from 
human activities that exceeds ambient levels or interferes with normal 
sound production or reception by sea otters. The terms ``acoustic 
disturbance'' or ``acoustic harassment'' are disturbances or harassment 
events resulting from noise exposure. Potential effects of noise 
exposure are likely to depend on the distance of the 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 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 Planned by Hilcorp, Harvest, and Alaska
  Gasline Development Corporation That Produce Noise Capable of Causing
          Incidental Take by Harassment of Northern Sea Otters
------------------------------------------------------------------------
   Project component name &
           location                    Anticipated noise sources
------------------------------------------------------------------------
Anchor Point 2D seismic        Marine: 1 source vessel with airgun, 1
 survey.                        node vessel; Onshore/Intertidal: Shot
                                holes, tracked vehicles, helicopters.
OCS 3D seismic survey........  1 source vessel with airguns, 1 support
                                vessel, 1 or 2 chase vessels to maintain
                                security around streamers, 1 or 2
                                mitigation vessels.
OCS geohazard survey.........  1 vessel with echosounders and/or
                                subbottom profilers.
OCS exploratory wells........  1 jack-up rig, drive pipe installation,
                                support vessels, helicopters.
Iniskin Peninsula exploration  Construction of causeway, dredging,
 and development.               vessels.
Platform & pipeline            Vessels, water jets, helicopters, and/or
 maintenance.                   sub-bottom profilers.
NCI subsea well geohazard      1 vessel with echosounders and/or
 survey.                        subbottom profilers.
NCI well abandonment activity  1 jack-up rig, support vessel,
                                helicopters.
TB area geohazard survey.....  1 vessel with echosounders and/or
                                subbottom profilers.
TB area exploratory wells....  1 jack-up rig, drive pipe installation,
                                support vessels, helicopters.
Drift River terminal           Vessels.
 decommissioning.
------------------------------------------------------------------------
OCS = outer continental shelf, NCI = North Cook Inlet, TB = Trading Bay.

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 [mu]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), for descriptions of acoustical 
terms and measurement units in the context of ecological impact 
assessment. A summary of the noises produced by the various components 
of the planned activities is provided in tables 3 and 4.

[[Page 37720]]



  Table 3--Summary of Sound Source Levels for the Planned Oil and Gas Activities by Hilcorp/Harvest Alaska and
                                  Alaska Gasline Development Corporation (AGDC)
----------------------------------------------------------------------------------------------------------------
                                                        Sound pressure
            Applicant                  Activity        levels  (dB re 1        Frequency           Reference
                                                          [micro]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
                                   (1,945 cui          m.                                      2013; 81 FR 47240
                                   airgun).           185 dB SEL at 100                        (July 20, 2016).
                                                       m.
                                                      197 dB rms at 100
                                                       m.
Hilcorp/Harvest Alaska..........  3D seismic survey   217 dB peak at 100  <300 Hz...........  Austin and Warner
                                   (1,945 cui          m.                                      2013; 81 FR 47240
                                   airgun).           185 dB SEL at 100                        (July 20, 2016).
                                                       m.
                                                      197 dB rms 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.
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...........  URS 2007.
                                   Iniskin Peninsula   12-19 m.
                                   causeway.
Hilcorp/Harvest Alaska..........  Vibratory sheet     175 dB peak at 10   <100-2,500 Hz.....  Illingworth &
                                   pile driving for    m.                                      Rodkin 2007.
                                   Iniskin Peninsula  160 dB SEL at 10 m
                                   causeway.          160 dB rms 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..........  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 rms @1 m...  <2.5 kHz,           LGL/JASCO/
                                                                           broadband.          Greeneridge 2014.
----------------------------------------------------------------------------------------------------------------
SEL = sound exposure level.


    Table 4--Summary of Sound Sources of Pile-Driving Activities for Alaska Gasline Development Corporation (AGDC) From Illingworth & Rodkin (2007).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          Sound pressure level (dB re 1
                                                                                    [micro]Pa)
   Representative pile type and size            Hammer  type         ---------------------------------------         Project pile type  and size
                                                                          Peak         RMS          SEL
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch sheet pile....................  Impact......................          205          190          180  Sheet pile.
24-inch 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 
hearing ability spans 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 (e.g., Zalophus 
californianus). 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, 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

[[Page 37721]]

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 certain 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.
    NMFS' (2018a) criteria for sound exposure incorporate two metrics 
of exposure: The peak level of instantaneous exposure likely to cause 
PTS, and the cumulative sound 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 otariid 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 take by Level A harassment 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, b; 
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 may 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 planned activities include vibratory 
pile driving, vessel activities, use of a 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). 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 2015). 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.
    Although no specific thresholds have been developed for sea otters, 
several alternative behavioral response thresholds have been developed 
for pinnipeds. Southall et al. (2007, 2019) 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 other studies, and NMFS (2018a) has used the data to develop TTS 
threshold for otariid pinnipeds of 188 dB SELcum for 
impulsive sounds and 199 dB SELcum for non-impulsive sounds.
    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 37722]]

vibratory pile driving and other sources of similar low-frequency 
broadband noise, we assume 120 dB 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, 2019), 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. When behavioral observations during vibratory pile 
driving (ESNERR 2011) and results of behavioral response modelling 
(Wood et al. 2012) are considered, the application of a 160-dB rms 
threshold is most appropriate.
    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 ITR based on the work of 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 38 kHz that are greater than 
160 dB--for both impulsive and non-impulsive sound sources--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).
    The area in which underwater noise in the frequency range of sea 
otter hearing will exceed thresholds, is termed the ``area of 
ensonification'' or ``zone of ensonification.'' The ensonification zone 
in which noise levels exceed thresholds for Level A take is often 
referred to as the Level A harassment zone. The Level B harassment zone 
likewise includes areas ensonified to thresholds for Level B take of 
sea otters.

  Table 5--Summary of Thresholds for Predicting Level A and Level B Take of Northern Sea Otters From Underwater
                                    Sound Exposure in the Frequency Range 125
----------------------------------------------------------------------------------------------------------------
                                         Injury (Level A) threshold            Disturbance (Level B) threshold
         Marine mammals          -------------------------------------------------------------------------------
                                     Impulsive \1\      Non-impulsive \1\                    All
----------------------------------------------------------------------------------------------------------------
Sea otters......................  232 dB peak; 203 dB  219 dB SELCUM......  160 dB rms.
                                   SELCUM.
----------------------------------------------------------------------------------------------------------------
\1\ Based on National Marine Fisheries Service acoustic exposure criteria for take of otariid pinnipeds (NMFS
  2018a).
SELCUM = cumulative sound exposure level.

Noise-Generating Activities
    The components of the specified 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 that may cause disturbance. A brief 
description of potential impacts follows.
    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). But high-level noise exposure 
has been implicated in mass stranding events among whales (e.g., see 
Cox et al. 2006), and 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. Sounds produced by 
the instruments used for these surveys vary in terms of frequency 
bands, source levels, repetition rates, and beam widths. Operating 
frequencies range from roughly 300 Hz to several hundred kHz with peak-
to-peak 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 
(impact versus vibratory hammer) (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, 
and both methods will be used in Cook Inlet.
    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 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. Drilling and the associated 
noise from pumps and generators on the drill rig is not expected to 
produce underwater noise levels that will affect sea otters (e.g., see 
Richardson et al. 1995; Spence et al. 2007; Marine Acoustics, Inc. 
2011; Illingworth and Rodkin 2014).
    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 
[micro]Pa-m, and underwater received levels were 109 dB when the 
aircraft flew at an altitude of 152 m (500 ft) and

[[Page 37723]]

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 [micro]Pa for 
flights at 152 and 305 m (500 and 1,000 ft), respectively.
    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). 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). It is not known whether anchor handling will 
produce similar noise levels in Cook Inlet, but it will occur in areas 
where sea otters are uncommon and unlikely to be affected.
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 [micro]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, which scatter and reflect sound, reduce 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 [micro]Pa (see ``Noise-Generating Activities''), 
and so threshold shift is extremely unlikely.
    Loud screams are used to communicate between pups and 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 (e.g., red sea urchins (Mesocentrotus 
franciscanus), blue mussels (Mytilus spp.), butter clams (Saxidomus 
giganteus), etc.) eaten by otters and the shallow rocky areas and kelp 
(e.g., bull kelp (Nereocystis luetkeana) and dragon kelp (Eualaria 
fistulosa)) 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 planned 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. Docks can increase 
seafloor shading, which affects the amount of light penetration on the 
seafloor. Water quality 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, turban snails 
(Tegula spp.), octopuses (e.g., Octopus spp.), barnacles (Balanus 
spp.), sea stars (e.g., Pycnopodia helianthoides), scallops (e.g., 
Patinopecten caurinus), rock oysters (Saccostrea spp.), worms (e.g., 
Eudistylia spp.), and chitons (e.g., Mopalia spp.) (Riedman and Estes 
1990).
    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

[[Page 37724]]

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 effects of sound 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

    We provided discussion of relevant impacts to sea otters from oil 
spills and unpermitted discharges in our Federal Register notice of 
proposed rulemaking (84 FR 10224, March 19, 2019) and do not repeat 
that information here. Adverse impacts of exposure to oil is well 
documented for sea otters (e.g., Kooyman et al. 1976; Baker et al. 
1981; Costa and Kooyman 1982, 1984; Engelhardt 1983; Lipscomb 1996; 
Bickham 1998; Monson 2000; Albers 2003; Peterson 2003). 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. We do not 
anticipate effects to sea otters as a result of oil spills from this 
activity.

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 documented mortality from boat strike 
was similar to that reported for California: 2.7 otters per year (USFWS 
unpublished data). However, compared to otters in California, Alaska 
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 the specified activities in Cook Inlet causing a 
sea otter/vessel collision 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 can more easily avoid; and third, the specified activities will 
constitute only a small fraction of the total level of vessel traffic 
in the region, which increases the likelihood that otters in the 
project area are accustomed to avoiding vessels and will successfully 
avoid collisions with project vessels.
    The AGDC pipeline work and work by Hilcorp and Harvest on 
maintenance of existing facilities will be conducted in MCI, in areas 
that are outside of the normal range of sea otters. The unusual 
occurrence of otters in MCI makes vessel collisions extremely unlikely. 
Hilcorp and Harvest will conduct their 3D seismic work in offshore 
areas of LCI where otter densities are also low. They will conduct 2D 
seismic work along the eastern shoreline of LCI where densities are 
higher, but vessel speeds during the specified activities will be slow. 
Hilcorp/Harvest's seismic vessels would travel at approximately 4 knots 
(kn) or 7.4 km per hour (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/Harvest's maintenance activities 
will require the use of dive vessels, typically ranging up to 21 m (70 
ft) in length and capable of approximately 7 kn (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)

[[Page 37725]]

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 to reduce the risk of 
ship strike in all LOAs. We anticipate that vessel collisions involving 
a seismic-data-acquisition vessel towing gear 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 the 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 most of the 
project vessels, 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 project 
activities 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 2006; Maldini et al. 2012). 
In an example described by Pavez 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

[[Page 37726]]

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).
    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, turbulence at the water's 
surface limits the transference of sound from water to air. A sea otter 
with its head above water will be exposed to only a small fraction of 
the sound energy 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.
    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 marine 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 noise 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 noises 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 noise, these responses were often short-lived; the 
otters resumed normal activities soon after a new sound was introduced 
(Davis et al. 1987, 1988).
    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.

[[Page 37727]]

    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 specified 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 
project 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 minimize 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 specified 
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 the project noise or may already be 
habituated to noise due to previous and ongoing exposure to frequent 
air traffic and other activities in the area and will have little, if 
any, reaction to project activities.

Mitigation and Monitoring

    When the Service issues an ITR, we 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 measures are stipulated 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 noise associated with 
the activities, the following mitigation measures are required:
     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;
     Ramp-up procedures; and
     Vessel strike avoidance measures.
    This ITR establishes the process for evaluating specific activities 
in specific project areas and determining the appropriate mitigation 
measures to be included in an LOA. A marine mammal mitigation and 
monitoring plan (4MP) is required for all LOAs. The 4MP identifies the 
specific avoidance and minimization measures an applicant will take to 
reduce effects to otters. It describes the project in detail, assesses 
the effects, identifies effective means to avoid effects, and describes 
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 EZ. The EZ 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 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 ITR. The methodology for 
calculation of the radii will be described in each LOA and is 
identified in Sec.  18.137 Mitigation. Sound source levels will be 
monitored and evaluated in the field prior to conducting 2D and 3D 
seismic surveys. This on-site sound source verification (SSV) testing 
will be used to determine the size of the SZ and EZ for these 
activities. 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 
determine that the EZ is clear of sea otters prior to the start of 
daily activities or if activities have been stopped for longer than a 
30-minute period. The PSOs will ensure that no sea otters are observed 
in the EZ for a period of 30 minutes prior to work commencing.
    For the 2D survey, PSOs will be stationed on the source vessel 
during all seismic operations and geohazard surveys when the sub-bottom 
profilers are used. Because of the proximity to land, PSOs may also be 
stationed on land to augment the viewing area. For the 3D survey, PSOs 
will be stationed on at least two of the project vessels: The source 
vessel and the chase vessel. For the vertical seismic profiling, PSOs 
will be stationed on the drilling rig. For geohazard surveys, PSOs will 
be stationed on the survey vessel. The viewing area may be augmented by 
placing PSOs on a vessel specifically for mitigation purposes or using 
an unmanned aircraft system (drone). If drones will be used in areas 
with sea

[[Page 37728]]

otters, mitigation measures will be required to ensure drone use does 
not disturb otters. These measures may include maintaining a minimum 
altitude and horizontal distance no less than 100 m away from otters, 
conducting continuous visual monitoring by PSOs, and ceasing activities 
in response to sea otter behaviors indicating any reaction to drones.
    A power-down procedure will be in place during seismic work. It 
will provide the option of reducing the number of airguns in use, which 
reduces the EZ or SZ radius. Alternatively, a shutdown procedure may be 
necessary, during which all airgun activity is suspended immediately. 
During a power-down, a single airgun (``mitigation gun'') may be 
operated, 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 may 
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 or avoid 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 as soon as 
practicable upon the determination that a sea otter is either in or 
about to enter the EZ, and generally within several seconds. 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 or a 
reduced level of energy. If the complete EZ has not been visible for at 
least 30 minutes prior to the start of operations, operation of a 
mitigation gun may be required during the interruption of seismic 
survey operations prior to commencing ramp-up procedures. It will not 
be permissible to ramp up the full array from a complete shutdown in 
thick fog or at other times when the outer part of the Level A 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 sea otter appears likely to enter the EZ, further mitigative 
actions will be taken, i.e., further course alterations, power-down, or 
shutdown of the airguns.
    This ITR establishes the stakeholder engagement process that the 
applicant is required to undertake in order to obtain an LOA for 
incidental take of sea otters. This process is an ongoing collaborative 
process between the applicant, the Service, and subsistence users of 
sea otters. Stakeholder engagement efforts for the specified activities 
have been ongoing since mid-2018 and have indicated that a plan of 
cooperation (POC) is necessary for the Hilcorp and Harvest 3D seismic 
work. The POC must include a schedule for meeting with the affected 
communities, both prior to and while conducting the activities, a plan 
for resolving any conflicts, suggested means for resolving conflict, 
and process for notifying the communities of any changes in the 
operations.
    The measures described here and required in Sec.  18.137 through 
Sec.  18.140, Mitigation, Monitoring, Reporting Requirements, and 
Measures to Reduce Impacts to Subsistence Users, are those determined 
to achieve the least practicable adverse impact to northern sea otters 
and their availability for subsistence use. These mitigation measures 
were evaluated against a suite of possible alternatives to determine 
whether they would effect the least practicable adverse impact on the 
species, their habitat, and the availability of the species for 
subsistence uses.
    Alternative mitigation measures were evaluated but ultimately 
rejected as either not feasible, not practicable, not likely to be 
implemented effectively, or no more likely to be successful in reducing 
the impacts of the applicant's project. We considered requiring work to 
be paused or stopped to prevent exposure of northern sea otters to 
levels of noise exceeding a 160-dB Level B take threshold. The 
distances to the 160-dB sound isopleths for several of the specified 
activities are greater than 1 km (0.6 mi). Avoiding all northern sea 
otters within these distances would require work to shut down or power 
down for prolonged and repeated periods, which the applicant has 
determined would incapacitate the project. Therefore, this is not a 
practicable mitigation measure.
    The Service considered alternative mitigation measures based on 
observing and interpreting northern sea otter behaviors for preventing 
Level B harassment. Presently, mitigation protocols use sound exposure 
to predict behavioral responses rather than observing behavior 
directly. While direct observation of injury or the disruption of a 
behavioral pattern is the definitive criteria for identifying take once 
it has occurred, at present there is insufficient data to develop 
observation-based criteria for preventing harassment. Thus, monitoring 
of behavioral responses is useful for identifying take after it occurs, 
but not for preventing or mitigating it. As such, effectiveness of 
monitoring protocols based on behavior cannot be ascertained. 
Therefore, behavior-based mitigation was not a feasible alternative.
    We considered requiring the use of alternative technologies such as 
marine vibroseis to reduce or eliminate the

[[Page 37729]]

need for seismic airguns. Hilcorp and Harvest have requested takes of 
marine mammals incidental to the seismic survey operations described in 
the petition, which identified airgun arrays as the preferred data 
acquisition tool. It would be inappropriate for the Service to require 
the applicant to change the specified activity unless it was necessary 
to make the findings established for issuance of incidental take under 
the MMPA or necessary for achieving the least practicable adverse 
impact to the marine mammal stock. Currently, no alternative technology 
scaled for industrial use is reliable enough to meet the environmental 
challenges of operating in Cook Inlet. Many prototypes are currently in 
development and may ultimately become important for achieving the least 
practicable level of effect on marine mammals, but none of these 
technologies are currently practicable for use on a large scale in Cook 
Inlet.
    The option of designating seasonal exclusion areas within the 
specified geographic area was considered. However, no activities are 
planned in areas of Cook Inlet known to provide important habitat. 
Kachemak Bay, Kamishak Bay, and the designated critical habitat along 
the western shoreline of LCI and MCI are known areas of important 
habitat, but have not been identified as the target location of any 
planned activity in this rule. There is some information that suggests 
that the east coast of Cook Inlet along the Kenai Peninsula may be used 
seasonally by sea otters in late summer (BlueCrest 2013). Restrictions 
on seismic survey operations in this area during this time period might 
reduce the probability of disturbance of sea otters. However, there is 
currently insufficient information to support a seasonal restriction in 
eastern Cook Inlet. Little is known about the extent or duration of the 
use of the area by sea otters or what life-history functions the area 
supports. The benefit such a designation might offer is entirely 
unknown and, until additional information is available, remains 
speculative.
    Compensatory mitigation was considered. Some environmental laws 
allow compensatory mitigation, such as habitat restoration projects, to 
be used by the applicant to offset effects of the project activities 
that cannot otherwise be avoided. The Service is issuing an 
authorization for incidental take of sea otters under the MMPA. The 
MMPA requires that impacts be reduced to the least practicable level, 
but does not require offsets. The Service must consider the 
practicability of implementation of measures to reduce impacts, as well 
as proven or likely effectiveness of those measures. The impacts to sea 
otters and their habitat in Cook Inlet will be primarily acoustic and 
temporary in nature. We are not currently aware of literature 
demonstrating the effectiveness of habitat restoration for mitigating 
the effects of underwater noise. Additionally, we are not aware of any 
practicable habitat improvement projects in Cook Inlet that would have 
demonstrable benefits for the affected stocks.
    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 Sec.  18.27(d)(vii) stipulate 
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. SSV monitoring will 
be conducted to document sound levels produced by the work. 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 monitoring and 
reporting requirements are at Sec.  18.138 Monitoring and Sec.  18.139 
Reporting requirements.
    Alternative monitoring measures were considered, but they were not 
incorporated in this rule. Passive acoustic monitoring is appropriate 
for some species of marine mammals but is not indicated for sea otters, 
which are not known to vocalize extensively underwater. Visual 
monitoring during all times of day and night was rejected because 
limited visibility during periods of darkness would prevent the 
detection of animals. Thermal monitoring or monitoring of sea otters 
with unmanned aircraft systems (drones) has not yet been fully tested 
and evaluated for use in Cook Inlet, but may prove useful in the 
future. Requiring visual observation and PSO monitoring of 100 percent 
of all spatial areas within the 160-dB ensonification area was also 
considered, but for 2D and 3D seismic surveys in particular, this was 
not expected to be achievable. We instead accounted for all sea otter 
exposures to 160 dB or greater in our estimation of take, and we did 
not reduce this number to attempt to account for some proportion of the 
total that might be avoided when detected by PSO monitoring.

Estimated Incidental Take

    This section provides the number of incidental takes estimated to 
occur because of the planned activities. The number of takes were 
analyzed to make the required small numbers and negligible impact 
determinations.

Estimating Exposure Rates

    The Service anticipates that incidental take of sea otters may 
occur during the project 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 construction 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 sea otters to various stimuli.
    Sound exposure criteria provide the best available proxy for 
estimation of exposure to harassment. 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 take from project activities.
    No separate exposure evaluation was done for activities that do not 
generate underwater sound. Nearly all of the planned 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

[[Page 37730]]

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 exposure of sea otters to 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 the 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 MCI 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 noise levels 
capable of causing take from project activities. Many activities 
associated with oil and gas exploration, development, production, and 
transportation may result in underwater sounds that do 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 and Harvest'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, plug-and-abandon activities, and use of water jets 
during routine maintenance. AGDC's activities include pile driving and 
anchor handling.
    The number of exposures to underwater sound levels capable of 
causing take by Level A harassment from specific project elements was 
estimated using the thresholds recommended by NMFS (2018a,b) for 
otariid pinnipeds (232 dB peak and 203 dB SELcum). For Level 
B harassment we used a 160-dB threshold. We multiplied the estimated 
area of ensonification (km\2\), by the density of sea otters in that 
area (number (#) of otters per km\2\) to estimate the number of otters 
in the ensonified area. This value was then multiplied by the maximum 
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 planned 
activities, it is possible to consider the most likely reactions. Sea 
otters do not appear highly reactive to underwater sounds, but the 
presence of vessels may elicit stronger behavioral responses (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 the acoustic 
exposure criteria shown in table 5 would experience Level A or Level B 
take.

Calculating Take

    The total take of sea otters from these oil and gas activities in 
Cook Inlet was estimated by calculating the number of otters in the 
ensonified area during the full duration (the maximum number of days) 
of each project activity. After publication of the proposed ITR in the 
Federal Register, the applicant provided updates and minor 
modifications to their project plans. Changes included an increase in 
the 3D seismic survey line length from 74 km (46 mi) to 127 km (79 mi), 
an adjustment to account for the proportion of line length actively 
surveyed with the airgun array each day, use of a boomer rather than 
chirper sub-bottom profiler, and changes to the total duration (number 
of days) of pile driving and vertical seismic profiling in TB and LCI. 
The changes are reflected in the analysis presented here. Details of 
the project activities and calculations of take are included in the 
applicant's updated petition (June 2019) available at 
www.regulations.gov under docket number FWS-R7-ES-2019-0012. Methods 
used for calculating take did not change, but the resulting estimates 
have been updated. The total take increased from 1,666 to 1,687.
Distances to Thresholds
    To calculate the ensonified area, we first estimated the distances 
that underwater sound will travel before attenuating to levels below 
thresholds for take by Level A and Level B harassment. The distances to 
the Level A thresholds were calculated using the NMFS Acoustical 
Guidance Spreadsheets (NMFS 2018b) 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 updated 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

[[Page 37731]]

to experience take by Level A or Level B harassment.

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


                  Table 7--Calculated Distance in Meters (m) to Level A and Level B Thresholds
----------------------------------------------------------------------------------------------------------------
                                                               Level A--NMFS otariid                  Level B
                                                 ---------------------------------------------------------------
                    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               1             N/A           2,929
Pipe driving, Chinitna Bay......................            0.19           39.48             N/A           1,630
VSP.............................................            0.46          284.84             N/A           2,470
Vibratory sheet pile driving....................             N/A             N/A            0.46              10
Water jet.......................................             N/A             N/A            0.54           11.66
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            0.00
----------------------------------------------------------------------------------------------------------------
SEL = sound exposure level.

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 based on the distance to the Level A and Level B 
thresholds. 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, 
vibratory pile driving). For impulsive mobile sources (2D/3D seismic, 
sub-bottom profiler), the radial area was then multiplied by the 
distance of the line to be surveyed each day to get the total area of 
ensonification. Otters spend most of their time at the water's surface 
or below their last 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 shoreline. The daily area of 
ensonification was then multiplied by the duration of the activity in 
number of days and the density of otters in the applicable region of 
Cook Inlet to estimate the number of otters that might be taken. In 
total, 1,687 instances of take are expected. The total Level A take of 
sea otters in Cook Inlet over the 5-year course of this ITR is 
anticipated to be 3. The total number of takes from each project 
activity is presented in table 8.
    For some projects, like the 3D seismic survey, the design of the 
project is well developed; therefore, the duration is well defined. 
However, for other projects, the duration is not well developed, such 
as activities around the LCI 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 updated petition (June 2019). The 
durations used for each activity are provided in table 8. For Level B 
take, we assumed one take per otter per day regardless of duration of 
work within a day. The resulting estimate of the total number of Level 
B takes expected from planned oil and gas activities in Cook Inlet from 
2019 through the date 5 years from the effective date of the final rule 
is 1,684.
    The proposed ITR included calculation of the numbers of individual 
otters taken. Those estimates have been removed from this ITR because 
the methodology used to calculate take of individuals led to 
substantial uncertainty in the accuracy of the estimates. We here rely 
instead on the number of takes to determine the likely effects to the 
stock. The total number of takes is expected to be higher than the 
number of otters taken because, for example, a resident otter may be 
taken on each day of noise-generating activity.

[[Page 37732]]



                                                    Table 8--Estimate of Total Take for Each Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                              Level A                         Level B
                                                                                         ---------------------------------------------------------------
             Applicant                    Activity         Density  (#/      Duration                Impulsive             Non-impulsive
                                                              km\2\)          (days)     ---------------------------------------------------------------
                                                                                              232 pk          203 SEL         219 SEL         160 rms
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hilcorp/Harvest Alaska............  2D seismic..........           1.705          10.000           1.023           0.135  ..............         749.859
                                    3D seismic..........           0.026              60           1.155           0.152  ..............         846.896
                                    Vibratory sheet pile           0.026              20  ..............  ..............           0.000           0.000
                                     driving.
                                    Sub-bottom profiler-           0.026              28           0.001           0.014  ..............          46.291
                                     LCI.
                                    Sub-bottom profiler-           0.010               7           0.000           0.001  ..............           4.740
                                     NCI.
                                    Sub-bottom profiler-           0.010              14           0.000           0.003  ..............           9.479
                                     TB.
                                    Sub-bottom profiler-           0.010               3           0.000           0.000  ..............           2.031
                                     MCI.
                                    Pipe driving-LCI....           0.026              12           0.000           0.002  ..............           2.604
                                    Pipe driving-TB.....           0.010               6           0.000           0.000  ..............           0.501
                                    VSP-LCI.............           0.026               8           0.000           0.040  ..............           3.987
                                    VSP-TB..............           0.010               4           0.000           0.008  ..............           0.767
--------------------------------------------------------------------------------------------------------------------------------------------------------
AGDC..............................  Product Loading                0.010  ..............  ..............  ..............  ..............  ..............
                                     Facility.
                                    48-inch impact......  ..............              56           0.000           0.019  ..............           4.083
                                    60-inch impact......           0.010             106           0.000           0.036  ..............           7.728
                                    Temporary MOF.......           0.010  ..............  ..............  ..............  ..............  ..............
                                    18- and 24-inch       ..............             301  ..............  ..............           0.000           0.010
                                     vibratory.
                                    18- and 24-inch                0.010               7           0.000           0.000  ..............           0.510
                                     impact.
                                    48-inch impact......           0.010               7           0.000           0.002  ..............           0.510
                                    60-inch vibratory...           0.010              11  ..............  ..............           0.000           0.000
                                    sheet vibratory.....           0.010              66  ..............  ..............           0.000           0.000
                                    Mainline MOF........           0.010  ..............  ..............  ..............  ..............  ..............
                                    sheet vibratory.....  ..............               7  ..............  ..............           0.000           0.000
                                    sheet impact........           0.010               7           0.000           0.001  ..............           0.110
                                    Anchor handling.....           0.010              76  ..............  ..............           0.000           0.000
                                                         -----------------------------------------------------------------------------------------------
    Total.........................  ....................  ..............  ..............            2.18            0.42            0.00       1,683.108
--------------------------------------------------------------------------------------------------------------------------------------------------------
SEL = sound exposure level, LCI = Lower Cook Inlet, MCI = Middle Cook Inlet, NCI = North Cook Inlet, TB = Trading Bay, MOF = material offloading
  facility, VSP = vertical seismic profiling.

    The number of takes from each stock was estimated by categorizing 
each activity by its location relative to sea otter stock boundaries. 
Some activities will occur within both the southcentral Alaska and 
southwest Alaska stock boundaries. For these, take was assigned in 
proportion to the area of the activity within each stock region. Table 
9 shows the activities in relation to the sea otter stock boundaries as 
they were assigned for this analysis. The total number of takes of sea 
otters from the southwest Alaska stock is 418. The take number from the 
southcentral Alaska stock is 1,269.
    The total number of takes by Level A harassment is estimated to be 
2.6. When the total take from each activity (table 8) is multiplied by 
the proportion of that activity occurring within each stock boundary 
(table 9), the sum of take is 0.6 and 2 within the southwest Alaska and 
southcentral Alaska stocks, respectively. Because the number of takes 
from the southwest Alaska stock is 0.6, and take cannot occur unless it 
affects an animal, we rounded the number of takes from the southwest 
Alaska stock from 0.6 to 1. The total take is summarized in table 10.

                     Table 9--Percent of Each Activity Occurring Within Each Stock Boundary
----------------------------------------------------------------------------------------------------------------
                                                                                     Southwest     Southcentral
                   Applicant                                Activity               Alaska stock    Alaska stock
                                                                                        (%)             (%)
----------------------------------------------------------------------------------------------------------------
Hilcorp & Harvest Alaska......................  2D seismic......................  ..............             100
                                                3D seismic......................              44              56
                                                Vibratory sheet pile driving....             100  ..............
                                                Sub-bottom profiler--LCI........              44              56
                                                Sub-bottom profiler--NCI........             100  ..............
                                                Sub-bottom profiler--TB.........             100  ..............
                                                Sub-bottom profiler--MCI........             100  ..............
                                                Pipe driving--LCI...............              50              50
                                                Pipe driving--TB................             100  ..............
                                                VSP--LCI........................              50              50
                                                VSP--TB.........................             100  ..............
                                                Hydraulic grinder...............             100  ..............
                                                Water jet.......................             100  ..............
AGDC..........................................  Product Loading Facility
                                                   48-inch impact...............  ..............             100
                                                   60-inch impact...............  ..............             100
                                                Temporary MOF:
                                                   18-inch vibratory............  ..............             100
                                                   24-inch impact...............  ..............             100
                                                   48-inch impact...............  ..............             100
                                                   60-inch vibratory............  ..............             100

[[Page 37733]]

 
                                                   sheet vibratory..............  ..............             100
                                                Mainline MOF:
                                                   sheet vibratory..............  ..............             100
                                                   sheet impact.................  ..............             100
                                                   Anchor handling..............              50              50
----------------------------------------------------------------------------------------------------------------
LCI = Lower Cook Inlet, MCI = Middle Cook Inlet, NCI = North Cook Inlet, TB = Trading Bay, MOF = material
  offloading facility.


          Table 10--Summary of Estimates of Sea Otter Take by Level A and Level B Harassment and Stock
----------------------------------------------------------------------------------------------------------------
                                                                     Southwest     Southcentral
                 Type                         Unit of take         Alaska stock    Alaska stock         Sum
----------------------------------------------------------------------------------------------------------------
Level A...............................  Number of takes.........               1               2               3
Level B...............................  Number of takes.........             417           1,267           1,684
                                       -------------------------------------------------------------------------
    Total.............................  Number of takes.........             418           1,269           1,687
----------------------------------------------------------------------------------------------------------------

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 updated petition (June 2019). 
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 LCI they plan to conduct activities for one well; in MCI, 
they plan to conduct plugging and abandonment activities in the NCI and 
two wells in the TB area. In the third season, activities include 
drilling two wells in LCI. The final well in LCI 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 number of sea otters takes by year 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 during 2D seismic surveys were 
assigned to year 3. The resulting estimates of total Level B take 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
                                                                       NCI geohazard surveys....  LCI
                                                                       Pipeline maintenance       MCI
                                                                        (geohazard, water jet).
2020: Season 2......................  Hilcorp/Harvest................  2D seismic...............  LCI
                                                                       Drilling activities        LCI
                                                                        (geohazard, pipe
                                                                        driving, VSP) at 1 well.
                                                                       Drilling activities        MCI
                                                                        (geohazard, pipe
                                                                        driving, VSP) at 2 wells
                                                                        in TB.
                                                                       Plug and abandon           MCI
                                                                        activities (geohazard)
                                                                        at 1 well in the NCI.
                                                                       Pipeline maintenance       MCI
                                                                        (geohazard, water jet).
                                      AGDC...........................  Sheet pile driving at      MCI
                                                                        TMOF.
2021: Season 3......................  Hilcorp/Harvest................  Drilling activities        LCI
                                                                        (geohazard, pipe
                                                                        driving, VSP) at 2 wells.
                                                                       Sheet pile driving in      LCI
                                                                        Chinitna Bay.
                                      AGDC...........................  Pipeline maintenance       MCI
                                                                        (geohazard, water jet).
                                                                       Sheet pile driving at      MCI
                                                                        MMOF.
                                                                       Sheet pile driving at      MCI
                                                                        MMOF.
2022: Season 4......................  Hilcorp/Harvest................  Drilling activities        LCI
                                                                        (tugs, geohazard, pipe
                                                                        driving, VSP) at 1 well.
                                      AGDC...........................  Pipeline maintenance       MCI
                                                                        (geohazard, water jet).
                                                                       Impact pile driving at     LCI
                                                                        PLF: 80 48-inch piles,
                                                                        63 60-inch piles.
                                                                       Anchor handling for        MCI
                                                                        pipeline installation.
2023-2024: Season 5.................  Hilcorp/Harvest................  Pipeline maintenance       MCI
                                                                        (geohazard, water jet).
                                      AGDC...........................  Impact pile driving at     LCI
                                                                        PLF: 40 48-inch piles,
                                                                        80 60-inch piles.
                                                                       Impact pile driving at     LCI
                                                                        PLF: 10 48-inch piles,
                                                                        48 60-inch piles.

[[Page 37734]]

 
                                                                       Anchor handling for        MCI
                                                                        pipeline installation.
----------------------------------------------------------------------------------------------------------------
LCI = Lower Cook Inlet, MCI = Middle Cook Inlet, NCI = North Cook Inlet, 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 by Year (or Project Season)
----------------------------------------------------------------------------------------------------------------
                                                               Year (Project season)
                                 -------------------------------------------------------------------------------
              Take                 2019 (Season    2020 (Season    2021 (Season    2022 (Season    2023 (Season
                                        1)              2)              3)              4)              5)
----------------------------------------------------------------------------------------------------------------
Takes by year (season)..........             877             800               2               3               2
% takes by year (season)........             52%             48%              0%              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 may result in 
overestimation in take calculations from exposure to underwater noise, 
while our separate assumption that sea otters exposed to noise in the 
air but not in the water do not independently experience harassment may 
result in underestimation of take. 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 of density does not change. 
There is not enough information about the movement of sea otters in 
response to specific disturbances to refine these assumptions. 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 all otters will continue to 
respond in the same manner. Otters may remain in the area, depart from 
the area and return after activities are complete, or habituate to the 
disturbance and no longer experience take. However, we have no data to 
adjust for the likelihood of departure or habituation. In general, this 
situation is likely to result in overestimation of the number of takes. 
However, we also considered whether it would underestimate the impact 
of take because the same animal may be taken multiple times. For most 
animals, the effects of each repeated disturbance will be a short-term 
change in behavior which will have no lasting effect on the animal's 
survival or reproductive capacity. For a few animals, there may be more 
severe consequences. The net effect of this assumption is 
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 may 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 ITR will help fill this information 
need in the future, but for this suite of planned 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 this regulation must provide accurate project details, which 
may include minor changes from those described here. Minor changes to 
the details of the specified activities, such as a change of the 
specific vessels or a change in the start date of a specific activity, 
are not expected to significantly change the overall estimates of take 
or the conclusions reached in our analysis. In all cases, the most 
accurate information

[[Page 37735]]

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 rulemaking. Larger 
project changes that result in significantly different effects on sea 
otters would be outside of the scope of this ITR.

Potential Impacts on Sea Otter Stocks

    The estimated number of takes by Level B harassment is 1,684 
instances of take due to behavioral responses or TTS associated with 
noise exposure. Among otters from the southwest Alaska stock, 417 Level 
B takes are expected; and among the southcentral Alaska stock, 1,267 
takes from Level B harassment are expected. The estimated number of 
takes by Level A harassment is one from the southwest Alaska stock and 
two instances of take from the southcentral Alaska stock due to PTS 
associated with noise exposure. Combined, the expected number of Level 
A and Level B takes is 418 takes from the southwest Alaska stock and 
1,269 takes from the southcentral Alaska stock.
    These levels represent a small proportion relative to the most 
recent stock abundance estimates for sea otters. The estimated 418 
takes is 0.9 percent of the best available estimate of the current 
population size of 45,064 animals in the southwest Alaska stock (USFWS 
2014a) (418 / 45,064 = 0.009). The estimate of 1,269 takes is about 6.9 
percent of the 18,297 animals in the southcentral Alaska stock (USFWS 
2014b) 1,269 / 18,297 = 0.069). For these analyses, we are emphasizing 
the total number of takes rather than the number of animals taken. At 
this time, there are insufficient data regarding the daily movement 
patterns of individual sea otters in Cook Inlet to support an estimate 
of the number of animals taken. Evaluation based on total take in this 
situation is certain to be an overestimate of the actual impact, but it 
avoids relying on an estimate of number of animals taken that is 
precise, but possibly incorrect.
    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 specified 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 4MP 
and required by this 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 planned oil and gas 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 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. A POC will be 
prepared for 3D surveys planned by Hilcorp and 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. The 
statutory definition is provided at 16 U.S.C. 1362; however, the 
Service no longer relies upon or applies this regulatory definition. 
The Court of Appeals for the Ninth Circuit (Center for Biological 
Diversity v. Salazar, 695 F.3d 893, 902-907 [9th Cir. 2012]) has 
determined that the regulatory definition conflates ``small numbers'' 
with ``negligible impact,'' whereas the MMPA establishes these as 
separate standards.
    Our small numbers analysis evaluates whether the number of marine 
mammals anticipated to be taken is small relative or proportional to 
the size of the overall population. A more precise formulation of 
``small numbers'' is not possible because the concept is not capable of 
being expressed in absolute numerical limits. The Court of Appeals for 
the Ninth Circuit has expressly approved this type of analytical 
approach (Center for Biological Diversity v. Salazar, 695 F.3d at 905-
907).
    To evaluate whether the specified oil and gas activities in Cook 
Inlet would affect small numbers, we calculated the number of instances 
of take that are predicted to result from the specified activities. We 
then used the number of takes as a conservative estimate of the number 
of animals taken to determine whether more than a small number would be 
taken when compared with the size of the stock. We found that the 
proposed project may result in approximately 1,687 takes, of which, 418 
takes will be from the southwest Alaska stock and 1,269 takes will be 
from the southcentral Alaska stock. Based on most recent stock 
assessments (USFWS 2014a, b), the number of takes would equal about 1 
percent of the southwest Alaska stock and 6.9 percent of the 
southcentral Alaska stock.
    Evaluation based on total take rather than numbers of animals 
taken, is certain to be an overestimate of the actual impact because 
some otters are likely to be taken multiple times during the work. We 
determined it was appropriate to consider total take for these analyses 
as the best available data regarding the daily movement patterns of sea 
otters because there was not sufficient information to support an 
accurate estimate of the number of individual animals affected by the 
specific project activities. The available

[[Page 37736]]

information suggests that only a portion of the estimate of take will 
be realized. Based on these numbers, we find that the applicant's 
activities will take, by harassment, only a small number of animals 
relative to the population sizes of the affected stocks.

Negligible Impact

    We find 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 specified 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. Three otters may 
experience Level A take from PTS. The effects to these individuals are 
unknown, but lasting effects to survival and reproduction are possible. 
Thus, although the specified activities may result in approximately 418 
takes from the southwest Alaska stock and 1,269 takes from the 
southcentral Alaska stock, we do not expect this level of harassment to 
affect annual rates of recruitment or survival or result in adverse 
effects on the species or stocks. The focus on total take, rather than 
number of animals taken, for these analyses provides an overestimate of 
the effects on stocks.
    Our finding of negligible impact applies to incidental take 
associated with the specified activities as mitigated by the avoidance 
and minimization measures identified in the applicant's 4MP. 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 ITR. For these reasons, we find that the 
specified activities will have a negligible impact on sea otters.

Impact on Subsistence

    We find that the anticipated harassment caused by the applicant's 
activities will 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 specified 
activities and the timing and location of subsistence harvest 
activities in the area of the proposed project. We considered the 
comments received during the public comment period. 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 for project components that could have any adverse 
impact on subsistence harvest. We based our finding on: (1) Initial 
results of community outreach conducted by the applicant and the 
Service; (2) the results of aerial surveys indicating the availability 
of sea otters in Cook Inlet; (3) locations of hunting areas; and (4) 
the limited potential for overlap of hunting areas and proposed 
projects. The Service's confirms that through the coordination process 
identified in the ITR, no take of sea otters will be authorized that 
will result in an unmitigable adverse impact on the availability of sea 
otters for subsistence harvest sufficient to meet the needs of coastal 
dwelling Alaskan Natives.

Least Practicable Adverse Impacts

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

Monitoring and Reporting

    The purposes of the monitoring requirements are: To document and 
provide data for assessing the effects of specified activities on sea 
otters; to ensure that take is consistent with that anticipated in the 
small numbers, negligible impact, and subsistence use analyses; and to 
detect any unanticipated effects on the species. Monitoring plans 
include steps to document when and how sea otters are encountered, and 
their numbers and behaviors during these encounters. This information 
allows the Service to measure encounter rates and trends and to 
estimate numbers of animals potentially affected. To the extent 
possible, monitors will record group size, age, sex, reaction, duration 
of interaction, and closest approach to the project activity.
    Monitoring activities will be summarized and reported in a formal 
report each year. The applicant must submit an annual monitoring and 
reporting plan at least 90 days prior to the initiation of the 
activity, and the applicant must submit a final monitoring report to us 
no later than 90 days after the expiration of the LOA. We base each 
year's monitoring objective on the previous year's monitoring results. 
We require an approved plan for monitoring and reporting the effects of 
oil and gas industry activities on sea otters prior to issuance of an 
LOA. We require approval of the monitoring results for continued 
operation under the LOA.
    We find that this regulation will establish monitoring and 
reporting requirements to evaluate the potential impacts of planned 
activities and to ensure that the effects of the activities remain 
consistent with the rest of the findings.

Summary of and Response to Comments and Recommendations

    During the public comment period, we requested written comments 
from the public on the proposed ITR as well as the draft EA. The 
comment period on the proposed ITR opened on March 19, 2019 (84 FR 
10224), and, in response to requests from the public, was extended on 
April 5, 2019 (84 FR 13603). The comment period closed on April 19,

[[Page 37737]]

2019. We received 20 submissions; these included comments on the 
proposed rule and the draft EA as well as a number of publications and 
other documents submitted in support of those comments.
    The Service received comments from the Marine Mammal Commission, 
industry organizations, environmental organizations, local government 
entities, Tribal organizations, and the public. We reviewed all 
comments received for substantive issues, new information, and 
recommendations regarding the proposed ITR and the draft EA. The 
comments are aggregated by subject matter, summarized and addressed 
below, and changes have been incorporated into the final rule as 
appropriate. A summary of the changes to this final ITR from the 
proposed ITR is found in the preamble section entitled, Summary of 
Changes from the Proposed Rule.

General Comments

    Comment 1: Several commenters opposed the promulgation of the ITR 
based on a general opposition to oil and gas industry activities.
    Response 1: Language within section 101(a)(5)(A) of the MMPA 
requires the Service to allow the incidental taking of small numbers of 
marine mammals provided the Service has made certain determinations 
regarding the specified activity. Once we make the required 
determinations, we must promulgate the ITR. It is not our role in this 
process to approve or deny the specified activities. Our mandate is to 
identify and assess the potential impact of those activities on marine 
mammals, and if our analysis concludes that such impacts are consistent 
with the required determinations, we must promulgate an ITR.
    Comment 2: Allowing any level of harassment is a threat to the 
species.
    Response 2: We disagree. Based on our analysis we found that the 
effects of the specified activities will have no more than a negligible 
impact upon a small number of northern sea otters in Cook Inlet.
    Comment 3: There is insufficient information on how sound affects 
sea otters to determine the risks to the species; more research should 
be done.
    Response 3: While we acknowledge that additional research is needed 
to refine the evaluation of the effects of sound exposure on sea 
otters, we disagree with the comment that available information limits 
the Service's ability to conduct the required analysis and make the 
required determinations, which are based on the best scientific 
information that is available.
    Comment 4: The project actions will harm beluga whales.
    Response 4: The effects to marine mammals other than sea otters are 
outside of the scope of this rule and the authority of the Service. The 
NMFS has jurisdiction over issuance of incidental take of beluga whales 
and other cetacean and pinniped species in Cook Inlet.
    Comment 5: Seismic surveys can harm fish and invertebrates, thereby 
impeding prey availability and foraging for sea otters.
    Response 5: The Service evaluated effects of the proposed seismic 
surveys on sea otter prey availability to determine whether these 
effects would lead to incidental take of otters. See Potential Effects 
of the Activities, Effects on Habitat and Prey. As discussed in this 
final rule, the expected effects of the planned seismic surveys on sea 
otter prey will not result in lasting consequences for prey 
availability or additional take of sea otters.

Project Description

    Comment 6: The description of activities considered for the ITR is 
ambiguous. The Service should address these ambiguities and ensure that 
the ITR is very specific about what the applicant can and cannot do to 
make sure the LOA process is not open-ended.
    Response 6: We disagree. Consistent with numerous previous ITRs, 
this ITR provides an overall ``umbrella'' set of requirements which, 
when followed, allow the incidental take of small numbers of sea otters 
during certain oil and gas industry activities. The requirements ensure 
that there is no more than a negligible impact on these species, the 
activities will have the least practicable adverse impacts, and that 
there will not be unmitigable impacts on the availability of these 
species for subsistence use. The Service believes we have used the 
appropriate level of detail necessary to evaluate the effects of the 
specified activities within the 5-year period of the ITR consistent 
with requirements of the MMPA.
    Comment 7: Several commenters pointed out inconsistencies between 
the project descriptions and the description of activities in the 
proposed ITR.
    Response 7: We verified the project descriptions with the applicant 
and revised the project descriptions as needed in this final rule.

MMPA Requirements

    Comment 8: The public comment period should be extended; although 
it was extended from 15 to 30 days, it was still too short.
    Response 8: The Service determined that a 30-day comment period 
would be sufficient for this rulemaking.
    Comment 9: The Service should evaluate the harm and harassment of 
the proposed action on units smaller than stocks.
    Response 9: The Service believes that our evaluation of the 
proposed activities at the stock level is consistent with section 
101(a)(5) of the MMPA, which uses the term ``species or stock.'' We do 
not believe an evaluation at a larger or smaller scale is appropriate.
    Comment 10: Several commenters expressed concern that industry 
activities and incidental take authorization could have an adverse 
impact on Alaska Native subsistence use of sea otters. It was suggested 
that the Service should ensure that all applicants submit, as part of 
their LOA requests, a site-specific stakeholder engagement plan or POC 
that includes a summary of input received, a schedule for ongoing 
community engagement, and measures that would be implemented to 
mitigate any potential conflicts with subsistence hunting.
    Response 10: This ITR requires an LOA applicant to coordinate with 
Alaska Native villages and Tribal organizations to identify and avoid 
potential conflicts. If any conflicts are identified, the applicant 
must develop a POC specifying the particular steps that will be taken 
to address any effects the project might have on subsistence harvest. 
Appropriate mitigation measures will be developed if conflicts are 
identified. The applicant must conduct stakeholder engagement and make 
this information available to the Service. Revisions have been made to 
Sec. Sec.  18.134(b)(3) and 18.140(b) to incorporate these suggestions 
and provide additional detail and clarity regarding the required 
components of the stakeholder engagement plan and POC.
    Comment 11: Neither the applicant nor the Service consulted with 
federally recognized tribes or tribal organizations on this proposed 
activity.
    Response 11: We conducted outreach to all the tribal organizations 
in the Cook Inlet region by email and postal letters. We received one 
response requesting further consultation on this project from the 
Native Village of Chickaloon. No other groups expressed interest. When 
the Chickaloon Village Traditional Council (CVTC) and the Service were 
not able to schedule a time and place suitable to both parties to 
conduct the consultation, the CVTC chose to provide written comments to

[[Page 37738]]

the Service expressing their views on the ITR. See Comment 1 for our 
response.
    Comment 12: The Service conflates small numbers and negligible 
impact standards required by the MMPA.
    Response 12: We disagree. As we explain in the preamble of this 
ITR, we do not rely upon the definition of ``small numbers'' found in 
50 CFR 18.27 as it conflates ``small numbers'' with ``negligible 
impacts.'' We recognize ``small numbers'' and ``negligible impacts'' as 
two separate and distinct requirements under the MMPA. The Service 
maintains that the proposed oil and gas activities in Cook Inlet will 
affect a small number of animals and will have a negligible effect on 
the stocks, based on separate and discrete analyses for each of these 
criteria.
    Comment 13: The conclusions in the proposed ITR that the activities 
will have a negligible impact and take only small numbers are 
insufficiently supported.
    Response 13: We disagree. The Service analysis of the specified 
activities for this ITR used the best available information and 
encapsulated all of the applicant's known and anticipated activities 
that will occur in the Cook Inlet ITR Region during the 5-year period 
of this ITR.
    Comment 14: Cumulative impacts of multiple take authorizations in 
Cook Inlet must be considered.
    Response 14: In our negligible impacts assessment, we considered 
the effects of a suite of human activities on sea otters in Cook Inlet, 
including impacts from noise, vessel activities, human encounters, oil 
spills, cumulative effects of existing and future development, 
production, and exploration activities, and the likelihood of impacts 
from these activities. We incorporated these impacts into the baseline 
condition of the affected stocks to determine whether the issuance of 
take would have more than a negligible effect.

Estimation of Take

    Comment 15: The analysis does not adequately address effects of 
noise on mothers with pups.
    Response 15: While we acknowledge that mothers with pups are likely 
to be among the most sensitive individuals to harassment, we believe 
our analysis adequately addresses potential impacts to all life stages 
as discussed in the preamble.
    Comment 16: The estimates of numbers of takes and sea otters taken 
do not correctly allocate the proportion of takes between the 
southcentral and southwest Alaska stock resulting in underestimation of 
take from the ESA-listed southwest Alaska stock. Methods used to 
allocate take between stocks are insufficiently supported. The 
assignment of the Level A take to the southcentral Alaska stock is 
arbitrary.
    Response 16: We disagree. Take is calculated according to the 
location, duration, and intensity of the specific component of the 
work, and the density of sea otters exposed to work in that project 
area. Estimates of the number of takes was based on the proportion of 
each activity occurring within each stock boundary. For clarity, we 
have added a table showing what proportion of each activity is expected 
to occur within each stock boundary.
    In response to this comment, we reevaluated whether the allocation 
of Level A take was assigned to the appropriate stock. We determined 
that the appropriate procedures were used to estimate Level A take 
according to location and characteristics of the activity within each 
stock boundary. However, we acknowledge that is it more appropriate in 
this case to consider the total number of takes rather than the number 
of animals taken. This change resulted in revision of the Level A take 
estimate from three takes of one animal in the southcentral Alaska 
stock, to two instances of take from the southwest Alaska stock and one 
instance of take from the southcentral Alaska stock. Although we 
determined in this final regulation that it was more appropriate to use 
total takes rather than takes of animals, the proposed regulation, 
which presented both methods for considering take, was not arbitrary.
    Comment 17: Take is underestimated, and methods of take calculation 
are not adequately disclosed.
    Response 17: Take was calculated based on the best information 
available at the time of the analysis and was done in a manner that any 
necessary assumptions or estimates in input parameters would result in 
overestimation of take rather than underestimation. We have added 
additional text and an additional table to Estimated Incidental Take to 
help describe how these take estimates were calculated.
    Comment 18: The Service proposed that a very small number of sea 
otters could be taken by Level B harassment relative to the estimated 
number of sea otter takes. The number of individuals estimated to be 
taken during the course of the regulations is unrealistic based on the 
types of activities being conducted and the location and duration of 
those activities. Mobile activities, such as seismic and geohazard 
surveys, would be conducted over a large area and an extended period of 
time, resulting in the exposure of more individuals than would be 
exposed for stationary sources, such as pile driving.
    Response 18: We employed a model for estimating the number of 
animals taken based on the estimated number of takes. This model was 
based on the available information at the time of the analysis. We 
recognize that a more sophisticated model can be developed but, at this 
time, there are insufficient data regarding the behaviors and movement 
patterns of individual sea otters in Cook Inlet, and so we cannot be 
confident that a more sophisticated model would accurately translate 
the total number of takes into a more accurate estimate of the number 
of animals taken. Therefore, rather than attempting to recalculate the 
number of animals taken using a more sophisticated model that may be no 
more accurate, we instead emphasize the importance of the total number 
of takes in this final rule. We have evaluated whether the MMPA 
determinations can be made based on the total number of takes rather 
than solely on the number of animals taken in order to ensure that our 
assessments do not underestimate the possible impacts to the stocks. 
This approach has been used in previous analyses of incidental take of 
marine mammals, both explicitly and implicitly, when a suitable 
estimate of numbers of individuals could not be derived from available 
information (e.g., 81 FR 52276, August 5, 2016; 81 FR 40902, June 23, 
2016). Using total take to evaluate the effects of the specified 
activities on sea otters in Cook Inlet is likely to be an overestimate 
of the actual impact, but it avoids relying on an estimate of number of 
animals taken that is precise, but possibly incorrect.
    Comment 19: The proposed pile-driving activities will harm and 
harass sea otters beyond the minimal estimates provided by the Service.
    Response 19: We have determined that in the proposed ITR, we 
underestimated the duration of pile-driving activities, but in 
cooperation with the applicant, we have incorporated more accurate 
estimates of the time needed to complete these activities to ensure the 
effects are not underestimated. Further, the effects of specific pile 
driving activities will be evaluated in individual LOAs to ensure 
accurate project details are incorporated.
    Comment 20: The Service incorrectly concludes that harassing the 
same nine threatened sea otters 410 times will be inconsequential.

[[Page 37739]]

    Response 20: The comment misinterprets our analysis in three ways. 
As discussed in the response to Comment 18, the estimate of number of 
animals taken was based on a model derived from the total number of 
takes. However, for this suite of projects, the number of takes is a 
more accurate assessment of the total impact of the activity, and our 
assessment has been revised to reflect this. Secondly, for most 
animals, the effects of disturbance will be short-term changes in 
behavior, which will have no lasting effect on the animal's survival or 
reproductive capacity. While there may be more severe consequences for 
a few animals, our evaluation supports a determination that there will 
be no significant consequences on the stocks to which these animals 
belong, not that the effects to individual animals are inconsequential. 
Finally, there is an implied omission of assessment of repeated 
exposures. We addressed this issue in the text of the preamble in 
Potential Effects of the Activities and Characterizing Take.
    Comment 21: Airborne noise: The Service conflates exposures from 
underwater sound sources with disturbing activities that do not 
generate underwater sound. The proposed rule discounts the impacts of 
noise in the air. The Service's conclusion that all take from aerial 
surveys will be mitigated is arbitrary, and instead it must analyze the 
potential for take from all sources of air traffic associated with the 
activities.
    Response 21: We disagree. We evaluated the full suite of project 
activities to determine which are likely to cause sea otters to react 
in ways that indicate take by Level A and Level B harassment. Take from 
airborne noise was considered. We assessed the likelihood, frequency, 
and severity of Level A and Level B take from airborne noise. Further 
discussion of this issue can be found in the section on Airborne Sounds 
in Effects of Noise.
    Comment 22: The Service relies on avoidance to reduce sea otter 
take; however, this is arbitrary and capricious because displacement 
still amounts to harassment and even harm if it impedes a sea otter 
from foraging or resting in its preferred habitat.
    Response 22: The commenter has misinterpreted how take associated 
with displacement is characterized and estimated in this rule. 
Displacement indeed does constitute take if, as the commenter notes, it 
impedes a sea otter from foraging or resting in preferred habitat and, 
as we note, the resulting effort to forage or rest in suboptimal 
habitat results in a biologically significant affect to the animal. Not 
all displacement will cause take. Otters displaced to other areas of 
suitable habitat and otters that are displaced, but do not experience a 
biologically significant interruption in feeding or resting are not 
considered taken. The analysis of take includes all animals exposed to 
the specified activities that are expected to respond with behaviors 
that indicate a Level A or Level B take has occurred, including 
displacement leading to biologically significant interruption in 
feeding and resting. We used the best available evidence based on the 
biological characteristics and behaviors of sea otters, or a suitable 
proxy, and the characteristics of the planned activities to identify 
appropriate thresholds of exposure that are likely to result in take. 
We have identified and used the same thresholds for northern and 
southern sea otters in previous analyses (e.g., 83 FR 18077, April 25, 
2018; 82 FR 6627, January 19, 2017, 83 FR 18330, April 26, 2018). Where 
information was lacking, we used conservative assumptions to ensure 
take, including that associated with displacement, was not 
underestimated. In sum, take from displacement was incorporated in this 
analysis, and the characterization of take associated with such 
displacement was neither arbitrary nor capricious.
    Comment 23: Seismic surveys will likely affect marine mammals in a 
much larger area than anticipated by the application.
    Response 23. We disagree. While the proposed survey may be 
detectable to sea otters beyond the thresholds for take that we 
identified here, to constitute take by harassment, the effects of 
exposure must rise beyond detectability to cause a biologically 
significant disruption of behavior. Many animals will have non-
significant responses, including short term increases in vigilance, 
momentary startle responses, or short-term changes in body orientation 
or direction of travel. To distinguish between non-significant 
responses and those indicating take, the Service has used an exposure 
threshold of 160 dB for underwater noise. See the comments regarding 
use of a 120-dB threshold versus a 160 dB threshold (Comment 33) for 
more discussion on the suitability of this threshold.
    Comment 24: The upper end of the frequency of hearing for sea 
otters should be 38 kHz rather than 32 kHz.
    Response 24: We agree. This correction was made in the ITR.
    Comment 25: Two commenters pointed out that the proposed ITR 
evaluated vessel noise from tugs towing rigs but did not evaluate noise 
from transiting vessels and suggested that, if general vessel use is 
discounted as a source of potential harassment, use of the tug should 
be as well.
    Response 25: Tugs towing a rig are using high-powered engines and 
are often working in teams, resulting in higher levels of underwater 
noise than is typical of most vessel traffic. Tugs will be towing rigs 
to areas in Cook Inlet where these activities are unusual. Otters in 
these areas may show a greater level of vigilance or avoidance of these 
activities than for most vessel traffic due to the novelty of the 
activity in that area. We do not typically consider vessel traffic to 
have the potential to result in take, but the applicant had initially 
requested authorization of take that may occur during tug towing. The 
Service evaluated the expected number of takes associated with tug 
towing and found this activity would likely result in less than one 
take. Accordingly, the applicant has since removed this request from 
its application and the Service has removed tug towing from the 
activities included in the final rule.
    Comment 26: Anchor handling, pipe cutting, and grinding do not emit 
sound levels sufficiently high to cause Level A or B harassment and 
should not be included in the analyses.
    Response 26: For activities with source levels nearing take 
thresholds, the possibility of take was analyzed at the request of the 
applicant and included in the overall take estimate in the proposed 
rule. Results of our analyses indicated that take associated with these 
activities is negligible. The applicants have since requested 
withdrawal of grinding and pipe cutting from consideration but have 
maintained inclusion of anchor handling. These changes are reflected in 
this rule.
    Comment 27: Several commenters expressed that a 160-dB re 1 [mu]Pa 
threshold is inadequate as it addresses only acoustic harassment and 
does not account for takes resulting from behavioral changes, 
particularly for continuous, non-impulsive sound sources.
    The Marine Mammal Commission recommended that, until such time that 
the 120- and 160-dB re 1 [mu]Pa thresholds are updated, the Service use 
a 120- rather than 160-dB re 1 [mu]Pa threshold to estimate the extents 
of the Level B harassment zones and numbers of sea otter takes when 
non-impulsive, continuous sources are proposed for use. The Commission 
further recommended that, if the Service did not use a 120-dB 
threshold, then a 141-dB Level B harassment threshold should be used 
for non-impulsive, continuous sources based on monitoring data from

[[Page 37740]]

the Elkhorn Slough National Estuarine Research Reserve (ESNERR) (2011).
    Response 27: The highest spectral densities for noises generated by 
vibratory pile driving lie within a range of frequencies at which sea 
otters have poor hearing ability. In contrast, gray whales, on which 
the 120-dB threshold is based, are highly sensitive to sounds within 
this frequency range. We do not dispute that sea otters may hear and 
may react to sounds produced by vibratory pile driving. However, we 
maintain that it is unlikely that sea otters' reactions will be 
equivalent to those of gray whales in terms of the sound levels that 
elicit reactions equivalent to take by harassment. Thus, it is not 
appropriate to apply the 120-dB threshold to sea otters.
    The Service disagrees with the Commission's conclusions regarding 
ESNERR (2011). After considering the Commission's comments and 
reviewing the monitoring data (ESNERR 2011 and ESNERR unpublished data 
2018), we reaffirm our statement that ``project-related monitoring of 
sea otter behavior in areas exposed to underwater sound levels ranging 
from approximately 135-165 dB during vibratory pile driving (ESNERR 
2011) showed no clear pattern of disturbance or avoidance in relation 
to these levels of underwater sound exposure.''
    As such, we maintain that use of a 160-dB threshold for both 
impulsive and non-impulsive sounds is consistent with the best 
available information.
    Comment 28: The tables summarizing source levels, repetition rates, 
pulse durations, weighting factor adjustments, and other assumptions 
for survey instruments were incorrect or inappropriate.
    Response 28: Discrepancies or errors of the source levels and other 
parameters for sound sources have been corrected in this rule.
    Comment 29: The Commission recommended that chirps have temporal 
and spectral characteristics suggesting that a lower, more 
precautionary Level B harassment threshold of 120 dB would be more 
appropriate than the 160-dB threshold. The Commission further 
recommended that, until the behavior thresholds are updated, the 
Service requires applicants to use the 120- rather than 160-dB 
threshold for intermittent, non-impulsive sources (such as chirps).
    Response 29: The Service considers sub-bottom profilers, including 
chirps, to be impulsive sources. Continuous sounds are characterized by 
having a sound pressure level that consistently stays above ambient 
levels and negligible fluctuations (NIOSH 1998; ANSI 2005). 
Intermittent sounds, with cyclical periods of lower or no sound level, 
can further be classified as either impulsive or non-impulsive. 
Impulsive sounds are brief (less than 1 second) and transient, with 
rapid rise time to a high peak pressure followed by a rapid decay (ANSI 
1986; NIOSH 1998). Non-impulsive sounds have more gradual rise times 
and gradual decays. Sounds from sub-bottom profilers more closely 
resemble impulsive sounds, as opposed to non-impulsive or continuous 
sounds, and the Service treats them as such.
    Regardless of how sounds emitted by chirps are classified, the 
references cited by the Commission in support of use of a 120dB 
threshold are overwhelmingly based on cetaceans in the high-frequency 
and mid-frequency functional hearing groups (harbor porpoise, killer 
whale, beaked whale, sperm whale, Lagenorhynchus and Stenella 
dolphins). These animals have significantly greater sensitivity to and 
utilization of high frequency sounds, therefore the results of those 
studies are not applicable to sea otters.
    Comment 30: The Commission strongly suggested that the Service 
consult with NMFS regarding the appropriateness of the various 
thresholds. The Commissions also recommended that the Service take a 
more active role in the development, review, and implementation of any 
and all acoustic and behavior thresholds for marine mammal species 
under its jurisdiction and consult with NMFS on whether, when, and how 
NMFS' current thresholds should be implemented.
    Response 30: The Service responded to the Commission's previous 
letters and advice consistent with our repeated response here. The 
Service continues to evaluate impacts resulting from anthropogenic 
sound on marine mammals under our jurisdiction using the best available 
information. We are aware of and supportive of the efforts by NMFS and 
its Science Centers to develop their Technical Guidance for Assessing 
the Effects of Anthropogenic Sound on Marine Mammal Hearing Acoustic 
Guidelines for those species under NMFS' jurisdiction. Although the 
Service provided informal comments on an early version of these 
guidelines, we did not provide additional comments because the guidance 
is specific to management of species under the jurisdiction of the 
Department of Commerce. The Service will continue to work with our 
partners, including the U.S. Geological Survey and NMFS, to obtain the 
best scientific information concerning potential effects of 
anthropogenic sound on marine mammal species under our jurisdiction.

Mitigation and Monitoring Comments

    Comment 31: Several commenters indicated the need for additional 
Protected Species Observers to monitor Level A and B harassment zones.
    Response 31: The issuance of an LOA for the specific activities 
under this ITR is contingent upon an applicant developing and 
implementing a detailed monitoring plan to ensure that the effects of 
the activities on marine mammals are documented and reported. If the 
monitoring plan is incomplete, inadequate, or not implemented, the LOA 
will not be issued, or if issued, may be rescinded.
    Effective monitoring is a necessary component of this rule. An 
applicant for an LOA must submit, as part of the application, a 
detailed marine mammal monitoring and mitigation plan. It must include 
a sufficient number of PSOs to conduct visual project monitoring of 100 
percent of a project's EZs during all daytime periods of underwater 
noise-generating work. Sea otters in the SZ must be documented and 
reported. These monitoring methods, included in this rule, were 
evaluated and found to be sufficient for detecting responses to project 
activities. We considered alternative monitoring methods and added a 
discussion of mitigation measures considered but not required in the 
section on the Mitigation and Monitoring.
    Comment 32: The Service should clarify that ramp up procedures for 
vibratory pile driving differ from those for impact pile driving.
    Response 32: Clarifying text has been added to Sec.  
18.137(b)(4)(ii).
    Comment 33: Mitigation requiring shut downs to be accomplished 
within several seconds does not adequately consider worker health and 
safety, and equipment safety and integrity. The Service should consider 
modifying this language from ``within several seconds'' to ``as soon as 
is practicable considering worker safety and equipment integrity''.
    Response 33: The suggested text has been added to Sec.  
18.137(b)(7)(ii).
    Comment 34: Mitigation measures apply to ``in-water work along the 
shoreline'' however, this term is not defined. The Service should 
replace the phrase ``in-water work along the shoreline'' with ``work 
occurring in intertidal areas.''
    Response 34: The suggested clarifying change was made to Sec.  
18.137(c)(2).
    Comment 35: Hilcorp and Harvest's 4MP states that they plan to 
perform a sound source verification (SSV) for the 3D seismic survey in 
LCI and will work with the Service to determine if an SSV is needed for 
other activities occurring

[[Page 37741]]

in the project area. However, the Service did not include a requirement 
in the proposed rule for any applicant to conduct an SSV for any 
seismic or other activities. The Commission recommended that the 
Service require the applicant to conduct SSVs at the beginning of 
noise-generating activities for any sound sources for which in-situ 
measurements have not been made for similar activities in Cook Inlet 
and use those measurements to verify and adjust, if necessary, the 
extents of the Level A and B harassment zones.
    Response 35: The omission of the SSV requirement for the 3D seismic 
survey in Cook Inlet is noted and has been corrected in this rule. We 
will work with the applicant to determine whether additional SSVs for 
other planned activities are appropriate and necessary.
    Comment 36: The Service has proposed to use power-down procedures 
during seismic survey activities as an alternative to implementing a 
full shutdown when an animal is detected within or approaching the 
Level A harassment zone, which would necessitate a ramp-up of the full 
array. Power-downs also may be used at the operator's discretion to 
reduce the likelihood of a Level B harassment take. In a mitigation and 
monitoring workshop for seismic surveys, industry representatives 
indicated that power-downs may ultimately increase sound input to the 
marine environment due to the need to subsequently re-shoot the 
trackline to prevent gaps in data acquisition (unpublished workshop 
report cited in 82 FR 26255, June 6, 2017). For that reason and because 
a power down may not actually be useful, NMFS has prohibited the use of 
power-downs in its issuance of incidental harassment authorizations for 
taking of marine mammals associated with geophysical surveys in the 
Atlantic Ocean (83 FR 63350, December 7, 2018), which the Commission 
supported. The Commission therefore recommends that the Service 
prohibit using power-down procedures as a mitigation measure for 
seismic surveys in Cook Inlet.
    Response 36: The Service agrees that, generally, it is best to 
minimize survey gaps and re-shoots. We disagree with the Commission's 
assertion that a voluntary power-down to avoid Level B take is not 
potentially useful.
    In the instance of avoiding Level A take, mitigation is not 
voluntary. Either a power-down or a shutdown would interrupt survey 
activity to a degree that will create a survey gap requiring re-shoot. 
Regardless of which of the two options is applied, a duration of longer 
than 10 minutes would require a ramp-up to restore the array to full 
power.
    Survey gaps are undesirable to operators as they result in a loss 
of data continuity and there are significant costs associated with 
reshoots. The Service thinks it unlikely that an operator would choose 
to employ voluntary shutdowns either frequently or frivolously. In an 
encounter with an unusually large group of animals, a voluntary power-
down may prevent exposure of a larger number of animals than would be 
exposed during infill shooting at a later time with typical encounter 
rates or group sizes. While we would encourage observers and operators 
to use voluntary power-downs as infrequently as is practicable, we feel 
that prohibition of this mitigation measure may ultimately result in an 
increase in exposure of marine mammals to noise.
    Comment 37: The Service also would allow the use of a 10-in\3\ 
mitigation gun to avoid requiring operators to ramp up after the full 
array has not been in use (e.g., during a line turn, low-visibility 
conditions, or other short-term interruption of seismic survey 
activities). In its issuance of incidental harassment authorizations 
for taking of marine mammals associated with geophysical surveys in the 
Atlantic Ocean, NMFS required that the acoustic source be deactivated 
when not acquiring or preparing to acquire data, except as necessary 
for testing, and that unnecessary use of the acoustic source be avoided 
(83 FR 63351, December 7, 2018). The Commission supports that 
requirement for the reasons previously stated and recommends that the 
Service prohibit the use of a mitigation gun to avoid implementing 
ramp-up procedures.
    Response 37: The Commission has mischaracterized the Service's 
proposed use of a mitigation gun; specifically, the proposed ITR did 
not suggest that ramp-up procedures may be avoided by use of a 
mitigation gun. Rather, we proposed use of a mitigation gun to reduce 
the probability of the presence of undetected animals within the SZ 
prior to initiation of ramp-up procedures during periods of poor 
visibility.
    While it is true that IHAs recently issued by NMFS for seismic 
surveys in the Atlantic prohibited airgun use during line turns and 
other short-term interruptions of survey activities, the use of Passive 
Acoustic Monitoring (PAM) was authorized as an avenue to clear the SZ 
of marine mammals and initiate ramp-up procedures during times when the 
SZ would not be visible (e.g., at nighttime or during periods of rain 
or fog). The Service does not believe PAM to be an effective monitoring 
and mitigation tool for Hilcorp and Harvest's proposed survey because 
(1) the high levels of ambient noise in Cook Inlet interfere with 
detections of underwater vocalizations; and (2) sea otters are not 
known to make underwater vocalizations. The Service contends that, 
within Cook Inlet, the use of a mitigation gun during line-change turns 
remains among the best practices to reduce the probability of animals 
being present within the SZ immediately prior to and during ramp-up 
procedures.
    Comment 38: The Service has proposed that operators notify the 
Service or the Alaska Sea Life Center within 48 hours of an injured, 
dead, or distressed sea otter being observed, irrespective of whether 
an injury or death was associated with the specified activities 
(Sec. Sec.  18.136(b) and 18.139(f) of the proposed rule). Any injury 
or death of a sea otter associated with the specified activities should 
be reported immediately to the Service or the Alaska Sea Life Center. 
And, in the past, the Service has specified that notification of 
injured or dead otters not associated with project activities occur 
within 24 hours to allow for a more timely response by trained 
personnel as warranted. As such, the Commission recommends that the 
Service require the operators to notify the Service or the Alaska Sea 
Life Center as follows: (1) Immediately if a sea otter is injured or 
killed during any of the project activities; and (2) within 24 hours of 
observing an injured, dead, or distressed sea otter that the observer 
determined is not associated with project activities.
    Response 38: The applicant has committed to notifying the Alaska 
Sea Life Center and the Service as recommended.
    Comment 39: The Service should employ time or area restrictions to 
mitigate acoustic impacts rather than relying on lookouts aboard 
vessels because many disruptions to marine mammal behavior will be 
difficult to detect or avoid through lookouts.
    Response 39: We disagree. There is no information currently 
available about daily or seasonal movement patterns of otters in Cook 
Inlet on which to base effective timing restrictions. Ship-based PSOs 
are limited in their ability to monitor sea otter behaviors, but this 
remains the most effective way to ensure the project activities will 
have the least practicable adverse impact on sea otters in Cook Inlet.
    Comment 40: The Service cannot, as it has here, rely on a plan to 
make a plan to mitigate the impacts of the specified activities on sea 
otters. It also may not

[[Page 37742]]

rubberstamp the mitigation measures proposed by the applicant, but it 
must consider the practicality of other measures.
    Response 40: The mitigation measures that have been developed for 
the project are developed based on the industry standards for seismic 
surveys, geotechnical work, pile driving, and other oil and gas work. 
The mitigation measures presented in the section on Mitigation and 
Monitoring and in this rule under Sec.  18.137 Mitigation include the 
mitigation measures required by regulation and the full suite of marine 
mammal monitoring and mitigation measures for activities proposed by 
Hilcorp and Harvest, and are incorporated here by reference 
(Fairweather Science LLC 2018). The AGDC will be expected to implement 
similar measures and meet similar standards for monitoring. Although 
site-specific 4MP will be required for an applicant to obtain an LOA 
under this rule, the expectations for the content of these plans are 
well established and constitute substantially more than ``a plan to 
make a plan.''
    Additionally we have added language to the section on Mitigation 
and Monitoring, and have summarized our assessment under Findings, 
Least Practicable Adverse Impacts. That language describes alternative 
mitigation measures that were considered and demonstrates why we 
determined that the selected mitigation will achieve the least 
practicable adverse impact of the proposed actions on sea otters. We 
have worked with Hilcorp, Harvest, and AGDC to incorporate these 
measures into their project plans as much as possible to ensure that 
these measures are practicable and will be implemented as intended. The 
mitigation measures required by this rule are therefore reflected in 
the application documents.
    Comment 41: The Service should consider requiring alternative 
technologies to seismic surveys.
    Response 41: We considered whether alternative technologies should 
be required. We added language to the section on Mitigation and 
Monitoring describing our evaluation.
    Comment 42: The Service should require lowest practicable source 
levels for seismic surveys and in-situ sound source verification for 
accurate EZs.
    Response 42: Hilcorp and Harvest have determined that the minimum 
source level necessary to provide the target data will be between 1,760 
in\3\ and 2,400 in\3\. The anticipated seismic source is a 14-airgun 
array with a total volume of 1,945 in\3\. We evaluated the possible 
effects on sea otters of the use of a 2,400 ci\3\ array. We have 
included a requirement to use equipment that generates the lowest 
practicable source levels during seismic surveys. Onsite SSV testing 
will be conducted prior to 2D and (3D) seismic surveys. Mitigation 
measures (D) and (E) have been added to paragraph (b)(1)(ii) of Sec.  
18.137 Mitigation.
    Comment 43: The Service should prescribe compensatory mitigation, 
such as habitat restoration, for the adverse impacts of the permitted 
activity on marine mammals and their habitat that cannot be prevented 
or mitigated by modifying the activity.
    Response 43: Compensatory mitigation is not required under the 
MMPA. Mitigation measures must be specified that achieve the least 
practicable adverse impact of the action on sea otters in Cook Inlet. 
No effective or practicable compensatory mitigation efforts have been 
identified for sea otters in this area. We added this information to 
the discussion of mitigation measures considered but not required under 
the section on Mitigation and Monitoring.
    Comment 44: Because sea otters may be sensitive to seismic surveys 
at the 160 dB threshold, or Level B take; the EZ should be extended and 
comprehensively monitored.
    Response 44: The EZ is the area where work that generates noise 
above Level A thresholds in the frequency range audible to sea otters 
must shut down or power down when sea otters are present. The EZ is 
comprehensively monitored. Work may not begin when 100 percent of the 
EZ is not visible or until after a 30-minute observation period has 
confirmed no otters are present in the EZ. Shutting down or powering 
down sound sources in response to the presence of sea otters in the 
160-dB zone (the SZ) would reduce take. However, the applicant has 
determined that shutting down or powering down sound sources in 
response to any sea otter in the 160-dB SZ would not be practicable for 
conducting the planned activities.
    Comment 45: Projects should be shut down during periods of limited 
visibility.
    Response 45: The applicant has indicated that it is not practicable 
to shut down during periods of low visibility and still complete the 
work. We recognize that this will limit the effectiveness of visual 
monitoring by PSOs and have accounted for this in our estimation of 
take.
    Comment 46: Bubble curtains or other noise-reduction technologies 
should be explored for use in the proposed project, as well as non-
pile-driven foundation types (e.g., gravity-based, or suction 
caissons).
    Response 46: The Service has determined that sound-attenuation 
devices and alternatives to pile-supported construction may be 
effective means for achieving the least practicable adverse impact of 
the specified activities. We have added evaluation of these tools on a 
project-by-project basis to the required mitigation measures of this 
rule. Each LOA will specify whether these tools will be required and 
what type will be used.
    Comment 47: Vessel speed should be limited to 10 knots or less.
    Response 47: Lowering vessel speed can reduce the risk of serious 
injury and mortality of marine mammals caused by ship strikes and can 
reduce ocean noise that can mask marine mammal communications. 
Requirements for vessels to reduce speed in the vicinity of sea otters 
or when visibility is limited are included in Sec.  18.137, paragraphs 
(d)(3) and (d)(5).

National Environmental Policy Act (NEPA)

    Comment 48: The draft EA is inadequate, and the Service must 
prepare a full environmental impact statement, and the draft EA fails 
to meet the requirements of NEPA.
    Response 48: Section 1501.4(b) of NEPA, found at 40 CFR Chapter V, 
notes that, in determining whether to prepare an environmental impact 
statement (EIS), a Federal agency may prepare an EA and, based on the 
EA document, make a determination whether to prepare an EIS. The 
Department of the Interior's policy and procedures for compliance with 
NEPA (69 FR 10866, March 8, 2004) further affirms that the purpose of 
an EA is to allow the responsible official to determine whether to 
prepare an EIS or a FONSI. The Service analyzed the proposed activity, 
i.e., issuance of implementing regulations, in accordance with the 
criteria of NEPA, and made a determination that it does not constitute 
a major Federal action significantly affecting the quality of the human 
environment. It should be noted that the Service does not authorize the 
actual oil and gas industry activities, as those activities are 
authorized by other State and Federal agencies. The Service merely 
authorizes the incidental take of sea otters resulting from those 
activities. We note that this ITR provides the Service with a means of 
interacting with the applicant through the mitigation, monitoring, and 
reporting requirements for individual projects to ensure that the 
impacts to sea otters are minimized. The ITR will authorize the 
nonlethal,

[[Page 37743]]

incidental take of only small numbers of sea otters, will have only a 
negligible impact on the species or stocks, and will not cause an 
unmitigable adverse impact on the availability of the species for 
subsistence use. As a result, we determined the regulations will not 
significantly affect the quality of the human environment and, 
therefore, a FONSI is appropriate. Accordingly, an EIS is not required 
under NEPA.
    Comment 49: The EA is overly narrow in scope, fails to evaluate 
alternatives, and does not adequately evaluate the potential impacts of 
the action on the physical and biological environment.
    Response 49: The Service believes the commenters misunderstand the 
requirements set forth in NEPA and the MMPA. The proposed action set 
forth in the EA is not activities proposed by Hilcorp, Harvest, and 
AGDC, but the issuance of incidental take authorization of sea otters. 
The Service believes we are in full compliance with both NEPA and the 
MMPA. We refer to our response to Comment 48 for an explanation of NEPA 
requirements and we refer to the Background section of the preamble of 
this rule for an explanation of MMPA requirements.
    In addition to the proposed action, we analyzed the ``no action'' 
alternative. The Service believes the no action alternative is valid 
and is in compliance with relevant court rulings (see, for example, 
Center for Biological Diversity v. Kempthorne, 588 F.3d 701, 9th Cir. 
2009). The action being considered is the issuance of the ITR. 
Therefore, the ``no action'' alternative would be not to issue an ITR. 
However, Section 101(a)(5)(A) of the MMPA specifies that the Secretary 
of the Interior (Secretary), through the Director of the Service, shall 
[emphasis added] 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 (other than commercial 
fishing) in a specified geographic region if the Secretary finds that 
the total of such taking will have a negligible impact on the species 
or stock and will not have an unmitigable adverse impact on the 
availability of the species or stock for subsistence uses. Therefore, 
if a citizen petitions the Service to promulgate regulations, we are 
required to initiate the process and make the appropriate findings. If 
there is no request for an ITR, there would be no need for any 
analysis, including alternatives.
    Comment 50: The Service's cumulative impacts analysis is deficient. 
The indirect and cumulative impacts of greenhouse gas pollution from 
operations and downstream consumption of fossil fuels must be analyzed, 
and effects of ocean warming and acidification must be considered.
    Response 50: The Service has considered the effects of climate 
change in our assessment of cumulative impacts. We considered the best 
available information regarding potential impacts of climate change and 
analyzed all relevant direct, indirect, and cumulative effects on sea 
otters, and their habitat, potentially caused by the specified 
activities in the Cook Inlet region during the 5-year period of this 
ITR. The level of analysis the commenters suggest is beyond the scope 
appropriate for this ITR. We do consider broader questions about 
climate change and how it may cause additive stress on sea otter 
populations over the long term generally in the EA. The Service finds 
that, while greenhouse gas emissions are clearly contributing to 
climate change, the comprehensive authority to regulate those emissions 
is not found in the statutes that govern the management of marine 
mammals. The challenge posed by climate change and its ultimate 
solution is much broader than the scope and scale of this ITR and EA.

ESA

    Comment 51: The Service must comply with the Endangered Species 
Act.
    Response 51: As required by section 7 of the ESA the Service has 
completed an intra-Service consultation under the ESA for the listed 
stock of sea otters and their critical habitat prior to promulgating 
this ITR.

Oil Spill Risks and Effects

    Comment 52: The project activities present an unacceptable risk of 
oil spills especially considering Hilcorp's aging infrastructure and 
poor record of safety and environmental compliance.
    Response 52: We acknowledge that an oil spill is a possible outcome 
of the specified activities in Cook Inlet, and for this reason we have 
discussed potential spills and their impacts to sea otters (see 
Potential Impacts from an Oil Spill or Unpermitted Discharge). It is 
beyond the authority of the Service and the MMPA to regulate potential 
accidental discharge into the environment. Waste product discharge into 
the environment is regulated under other laws and permits, such as 
provisions of the Clean Water Act (33 U.S.C. 1251 et seq.) and the Oil 
Pollution Act (33 U.S.C. 2701 et seq.), among others. However, we have 
considered the likelihood of spills resulting from the activities in 
Cook Inlet, and have determined that there is a low probability of a 
major spill. Small spills are more likely, but we have determined that, 
should they occur, they will likely affect only a small number of sea 
otters, will have a negligible impact on these stocks, and will not 
have an unmitigable adverse impact on their availability for 
subsistence uses.

Required Determinations

National Environmental Policy Act (NEPA)

    We have prepared an EA in accordance with the NEPA of 1969 (42 
U.S.C. 4321 et seq.) and have concluded that issuance of an ITR 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 is not a major Federal action 
significantly affecting the quality of the human environment within the 
meaning of section 102(2)(C) of the NEPA. A copy of the EA and the 
Service's FONSI 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 planned activities will 
occur within designated critical habitat found at 50 CFR 17.95(a). 
Prior to issuance of this final ITR, we completed an intra-Service 
consultation under section 7 of the ESA on our proposed issuance of an 
ITR. The evaluations and findings that resulted from this consultation 
are 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 (OMB) 
will review all significant rules for a determination of significance. 
OMB has designated this rule as not significant.
    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

[[Page 37744]]

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 of significance 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 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 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.). Hilcorp, Harvest, 
AGDC, and their contractors conducting exploration, development, 
production, and transportation of oil and gas in Cook Inlet, Alaska, 
are the only entities subject to this ITR. 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 specified 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 invited continued discussion about the proposed ITR.
    We received a request for Government-to-Government consultation on 
this ITR from the Chickaloon Village Traditional Council (CVTC). When 
the CVTC and the Service were not able to schedule a time and place 
suitable to both parties to conduct the consultation, the CVTC chose to 
provide written comments to the Service expressing their views on the 
ITR. We have responded to their comments under Summary of and Response 
to Comments and Recommendations and will continue to engage with CVTC 
to determine whether further consultation is desired.

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 includes 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 currently valid OMB 
control number.

[[Page 37745]]

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 were approved by OMB:
    (1) Remove references to 50 CFR 18 subpart I (expired); and
    (2) Add references to 50 CFR 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 Non-hour Burden Cost: $200,000.
    You may send comments on any aspect of this information collection 
to the Service Information Collection Clearance Officer, U.S. Fish and 
Wildlife Service, 5275 Leesburg Pike, MS: JAO/1N, Falls Church, VA 
22041-3803 (mail); or [email protected] (email). Please reference OMB 
Control Number 1018-BD63/0070 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 an applicant 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 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.

Regulation Promulgation

    For the reasons set forth in the preamble, the Service amends 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.

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.

    Regulations in this subpart apply to the nonlethal incidental, but 
not intentional, take, as defined in 50 CFR 18.3 and under the Marine 
Mammal Protection Act (16 U.S.C. 1362), 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 this incidental take regulation (ITR) 
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:
BILLING CODE 4333-15-P

[[Page 37746]]

[GRAPHIC] [TIFF OMITTED] TR01AU19.000

BILLING CODE 4333-15-C


Sec.  18.132   Dates this subpart is in effect.

    Regulations in this subpart are effective from August 1, 2019, to 
August 1, 2024.


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

    (a) To incidentally take marine mammals pursuant to the regulations 
in 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. The applicant is a U.S. citizen as defined in Sec.  
18.27(c).
    (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 these regulations in this subpart.


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

    (a) The applicant 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.

[[Page 37747]]

Documentation must include a list of persons contacted, a summary of 
input received, 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, including a schedule for ongoing community engagement 
and suggested measures that will be implemented to mitigate any 
potential conflicts with subsistence hunting.


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 to determine 
if the proposed activity is consistent with the analysis and findings 
made for these regulations. 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 onsite sound 
source verification (SSV), if available, or the best available science.
    (D) Onsite SSV testing will be conducted prior to two-dimensional 
(2D) and three-dimensional (3D) seismic surveys.
    (E) Seismic surveys (2D and 3D) must be conducted using equipment 
that generates the lowest practicable levels of underwater sound within 
the range of frequencies audible to sea otters.
    (iii) Summary of acoustic exposure thresholds for take of sea 
otters from underwater sound in the frequency range 125 Hz-38 kHz:

[[Page 37748]]



                                       Table 1 to Sec.   18.137(b)(1)(iii)
----------------------------------------------------------------------------------------------------------------
                                       Injury (Level A) threshold \1\          Disturbance (Level B) threshold
         Marine mammals          -------------------------------------------------------------------------------
                                       Impulsive          Non-impulsive                      All
----------------------------------------------------------------------------------------------------------------
Sea otters......................  232 dB peak; 203 dB  219 dB SELCUM......  160 dBRMS.
                                   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
  (drilling, water jet) 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. It will not be permissible to ramp up the 
full array 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.
    (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 determined clear of sea 
otters 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 for impact hammers 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. For vibratory hammers, initial noise generation will be 
limited to 15 seconds at a reduced energy level, followed by a 1-minute 
waiting period. This cycle will be repeated two additional times. 
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 or as

[[Page 37749]]

soon as practicable considering worker safety and equipment integrity.
    (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 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.
    (9) To ensure the proposed activities remain consistent with the 
estimated take of sea otters, operators may not conduct 3D seismic 
surveys where doing so will generate underwater noise levels that are 
likely to exceed acoustic exposure thresholds within areas of estimated 
sea otter densities greater than 0.026 otters per km. Maps of the areas 
will be provided to 3D seismic operators and may be adjusted based on 
SSV results. This does not apply to 2D seismic surveys.
    (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 work in intertidal areas shall be conducted during low tide 
when the site is dewatered to the maximum extent practicable.
    (3) The applicant must evaluate alternatives to pile-supported 
facilities. If no practicable alternative exists, the applicant must 
then evaluate the use of sound-attenuation devices such as pile caps 
and cushions, bubble curtains, and dewatered cofferdams during 
construction. The Service may require sound-attenuation devices or 
alternatives to pile-supported designs.
    (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 unless 
safety is a factor.
    (3) Vessels must reduce speed and maintain a distance of 100 m (328 
ft) from all sea otters unless safety is a factor.
    (4) Vessels must not be operated in such a way as to separate 
members of a group of sea otters from other members of the group.
    (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 must 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.
    (4) Unmanned aerial systems or drones must not cause take by 
harassment of sea otters. Measures for avoidance of take may be 
required in an LOA, and may include maintaining a minimum altitude and 
horizontal distance no less than 100 m away from otters, conducting 
continuous visual monitoring by PSOs, and ceasing activities in 
response to sea otter behaviors indicating any reaction to drones.


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

[[Page 37750]]

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, SSV 
results, 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 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 24 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 hours a day); 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;
    (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. The POC must include a schedule for ongoing community 
engagement and specific measures for mitigating any potential conflicts 
with subsistence hunting.


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. The applicant 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 
this requirement must be submitted to the Information Collection 
Clearance Officer, U.S. Fish and Wildlife Service, at the address 
listed in 50 CFR part 2.1.

    Dated: July 18, 2019.
Karen Budd-Falen,
Deputy Solicitor for Parks and Wildlife, Exercising the Authority of 
the Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 2019-16279 Filed 7-26-19; 4:15 pm]
 BILLING CODE 4333-15-P