[Federal Register Volume 77, Number 92 (Friday, May 11, 2012)]
[Notices]
[Pages 27720-27736]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-11296]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XA691


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Seismic Survey in Cook Inlet, AK

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; issuance of incidental take authorization.

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) 
regulations, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to the Apache Alaska 
Corporation (Apache) to take marine mammals, by harassment, incidental 
to a proposed 3D seismic survey in Cook Inlet, Alaska, between April 
2012 and April 2013.

DATES: Effective April 30, 2012, to April 30, 2013.

ADDRESSES: A copy of the IHA and application are available by writing 
to Jolie Harrison, Incidental Take Team Supervisor, Permits and 
Conservation Division, Office of Protected Resources, National Marine 
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910 or 
by telephoning the contacts listed here.
    A copy of the application used in this document may be obtained by 
writing to the address specified above, telephoning the contact listed 
below (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited 
in this notice may also be viewed, by appointment, during regular 
business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Brian D. Hopper, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to authorize, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    Authorization for incidental taking of small numbers of marine 
mammals shall be granted if NMFS finds that the taking will have a 
negligible impact on the species or stock(s), and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses (where relevant). The authorization must 
set forth the permissible methods of taking, other means of effecting 
the least practicable adverse impact on the specie or stock and its 
habitat, and requirements pertaining to the mitigation, monitoring and 
reporting of such takings. NMFS has defined ``negligible impact'' in 50 
CFR 216.103 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.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [``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 [``Level B harassment''].

Summary of Request

    NMFS received an application on June 15, 2011, from Apache for the 
taking, by harassment, of marine mammals incidental to a 3D seismic 
survey program in Cook Inlet, Alaska. After addressing comments from 
NMFS, Apache modified its application and submitted a revised 
application on July 19, 2011. The July 19, 2011, application was the 
one available for public comment (see ADDRESSES) and considered by NMFS 
for this IHA. On September 21, 2011, NMFS published a notice in the 
Federal Register (76 FR 58473) discussing the effects on marine mammals 
and making preliminary determinations regarding a proposed IHA. The 
notice initiated a 30 day public comment period, which closed on 
October 21, 2011.
    Apache's 3D seismic surveys would employ the use of two source 
vessels. Each source vessel will be equipped with compressors and 2400 
in\3\ airgun arrays, as well as additional lower-powered and higher 
frequency survey equipment for collecting bathymetric and shallow sub-
bottom data. In addition, one source vessel will be equipped with a 440 
in\3\ shallow water airgun array, which it can deploy at high tide in 
the intertidal area in less than 1.8 m of water. The proposed survey 
will take place in Cook Inlet.

[[Page 27721]]

During the effective period of the IHA, Apache anticipates conducting 
seismic surveys to cover an ~829 km\2\ (~320 mi\2\) area along the west 
coast of Cook Inlet from the McArthur River up and to the south of the 
Beluga river, in water depths of 0-128 m (0-420 ft). Apache intends to 
conduct transition zone marine surveys near intertidal areas in water 
depths of 0-54 m (0-177 ft) beginning in April 2012 and concluding in 
November 2012. Offshore areas will be surveyed in between April and 
September 2012 in water depths of 54-128 m (177-420 ft). Apache expects 
that it will take approximately 160 days--60 days in the nearshore 
region and 100 days in the offshore region--over the course of 8-9 
months to complete the survey. Impacts to marine mammals may occur from 
noise produced from active acoustic sources (primarily airguns) used in 
the surveys. There is also an onshore area that will be surveyed; 
however, this MMPA authorization only addresses takes from in-water 
activities because a sound source verification (SSV) study conducted in 
September 2011 indicated that in-water noise levels from explosive 
detonations onshore will not rise to a level of that would be 
anticipated to result in harassment of marine mammals in the water.

Description of the Specified Activity

    In 2010, Apache acquired over 300,000 acres of oil and gas leases 
in Cook Inlet with the primary objective to explore for and develop oil 
fields. In the spring of 2011, Apache conducted a seismic test program 
to evaluate the feasibility of using new nodal (i.e., no cables) 
technology seismic recording equipment for operations in the Cook Inlet 
environment and to test various seismic acquisition parameters to 
finalize the design for a 3D seismic program in Cook Inlet. The test 
program took place in late March 2011 and results indicated that the 
nodal technology was feasible in the Cook Inlet environment. Apache 
proposes to conduct a phased 3D seismic survey program throughout Cook 
Inlet over the course of the next three to five years. The first area 
proposed to be surveyed--and the subject of this IHA--is located along 
the western coast of mid-Cook Inlet.
    The survey operations will be performed from multiple vessels. 
Apache will employ the use of two source vessels. Each source vessel 
will be equipped with compressors and 2400 in\3\ airgun arrays. In 
addition, one source vessel will be equipped with a 440 in\3\ shallow 
water airgun array, which it can deploy at high tide in the intertidal 
area in less than 1.8 m of water. Three shallow draft vessels will 
support cable/nodal deployment and retrieval operations, and one 
mitigation/chase vessel will be used, which will also provide berthing 
for the Protected Species Observers (PSOs). Finally, two smaller jet 
boats will be used for personnel transport and node support in the 
extremely shallow water of the intertidal area. For additional 
information, such as vessel specifications, see Apache's application.
    To cover ~829 km\2\, the survey will take approximately 160 days to 
complete over the course of 8-9 months. Apache anticipates conducting 
survey operations 24 hours per day. During each 24 hour period, seismic 
operations will be active; however, in-water airguns will only be used 
for approximately 2.5 hours during each of the slack tide periods. 
There are approximately four slack tide periods in a 24-hour day, 
therefore, airgun operations will be active during approximately 10-12 
hours per day, if weather conditions allow.
    NMFS outlined the purpose of the program in a previous notice for 
the proposed IHA (76 FR 58473, September 21, 2011). The activities to 
be conducted have not changed between the proposed IHA notice and this 
final notice announcing the issuance of the IHA. For a more detailed 
description of the activity, including vessel and acoustic source 
specifications, the reader should refer to the proposed IHA notice (76 
FR 58473, September 21, 2011), the IHA application and associated 
documents referenced above this section.

Comments and Responses

    A notice of receipt of the Apache application and proposed IHA was 
published in the Federal Register on September 21, 2011 (76 FR 58473). 
During the 30-day public comment period, NMFS received comments from 
the Marine Mammal Commission (Commission), the Alaska Department of 
Fish and Game, environmental non-governmental organizations (NGOs), and 
one member of the public. Following are their comments and NMFS's 
responses:
    Comment 1: The Commission recommended that NMFS require the 
applicant to re-estimate the ensonified areas for each sound threshold 
(i.e., 190, 180, and 160 dB re 1 [micro]Pa) and the expected number of 
marine mammal takes, accounting for simultaneous, alternating use of 
two sound sources and the overlap of their acoustic footprints.
    Response: The two source vessels will survey the area using a 
``ping/pong'' technique. This method does not require the two vessels 
to fire their airgun arrays simultaneously. Instead, the first vessel 
fires the initial shot and then the second vessel fires its array about 
12 seconds later. The first vessel would then fire its second shot 12 
seconds after the second vessel has fired its airguns and so on. No 
other sources will be active at the same time as the airgun arrays 
because any additional sources may compromise the collection of seismic 
data from the airguns. As described in Section 6.2 of the IHA 
application, acoustic impacts were calculated based on the largest 
sound source, the 2400 in\3\ array, and included the ping/pong survey 
method described above. The calculations were performed for a 24-hour 
period of seismic survey activity. The estimated takes predicted with 
the 24-hour calculations factored in the 24-hour acoustic footprint, 
the estimated number of days surveyed in the respective depths, and the 
estimated marine mammal abundances.
    Comment 2: The Commission recommended that NMFS require the 
applicant to describe and provide the rationale for the method used to 
determine the density estimate for beluga whales away from river mouths 
and recalculate the density estimates accordingly.
    Response: The abundance estimate for belugas was derived from the 
highest daily mean count acquired during the annual surveys (i.e., the 
highest number of individuals observed in the area over the entire 
survey period). As noted in Section 6.3 of the IHA application, belugas 
are found in much higher concentrations in river mouths (e.g., 
Chickaloon Bay and Susitna Delta) compared to other areas. The 
applicant used the average number of belugas for the non-river mouths 
as a conservative estimate; however, in response to the Commission's 
recommendation, Apache has removed the Chickaloon Bay and Susitna Delta 
highest daily mean counts and re-calculated the maximum number of 
belugas observed, which results in higher abundance estimates for non-
river mouths. The revised average density is 0.00012 with a maximum of 
0.00037 for non-river mouths.
    Comment 3: The Commission recommended that NMFS require the 
applicant to recalculate the estimated number of takes for all species 
based on the modeled areas of ensonification for each sound threshold 
(i.e., 190, 180, and 160 dB re [micro]1 Pa), using the full number of 
survey days rather than half that number.
    Response: The acoustic footprints were calculated on a 24-hour 
basis, but surveys will only take place 12 hours per day; therefore, 
authorization for

[[Page 27722]]

marine mammal takes incidental to the seismic survey will only be 
necessary during 12 hours per day when surveys are conducted. In-water 
airguns will only be active for approximately 2.5 hours during periods 
of slack tide. There are approximately 4 slack tide periods every 24 
hours; therefore, airguns will be active approximately 10-12 hours per 
day, if weather conditions allow. Apache anticipates that a crew can 
acquire approximately 5.2 km\2\ per day, assuming an efficient crew can 
work 10-12 hours per day.
    Comment 4: The Commission recommended that NMFS require the 
applicant to either amend its application to seek authorization to take 
the full number of marine mammals that may be taken or provide 
sufficient justification for requesting lesser numbers of takes, 
particularly for beluga whales and harbor seals.
    Response: The application and NMFS' IHA authorize take for the 
total taking estimated. Estimating take begins with a mathematical 
formula, but may be adjusted upward or downward to account for factors 
such as effects of mitigation and monitoring and species group size. 
See the section in this Federal Register notice titled Estimated Take 
by Incidental Harassment, which has been updated for increased clarity, 
for an explanation of how take estimates were calculated for this 
activity.
    Comment 5: The Commission recommended that NMFS ensure that the 
monitoring measures included in the authorization are sufficient to 
account for all takes of marine mammals and require the applicant to 
provide timely reports of the number of marine mammals taken so that 
surveys can be stopped before the authorized takes are exceeded.
    Response: For this project, the required marine mammal monitoring 
serves two primary purposes. One purpose is to trigger mitigation 
measures--so when a marine mammal is sighted within or entering the 
identified 180 or 190 dB exclusion zones, appropriate measures are 
taken to minimize the likelihood that marine mammals are exposed to 
injurious sound levels; and under certain circumstances, mitigation 
action will be taken when marine mammals are sighted within or 
approaching the 160 dB zone. The second purpose is to collect data 
regarding the behavior and numbers of marine mammals detected within 
the 160 dB zone, which can be used to refine Level B harassment take 
estimates and contributes to our understanding of the nature and scale 
of marine mammals behavioral responses to seismic surveys. To better 
account for marine mammal takes that occur during the survey and ensure 
that takes do not exceed the amount authorized in the IHA, NMFS has 
included an additional reporting requirement in the IHA that will 
require the applicant to submit weekly and monthly reports to the 
Permits and Conservation Division. These reports will contain 
information regarding the species detected, in-water activity occurring 
at the time of the sighting, behavioral reactions to in-water 
activities, and the number of marine mammals taken. NMFS believes that 
the inclusion of a weekly and monthly reporting requirement will allow 
both NMFS and Apache to regularly track the number and nature of marine 
mammal takes, and ensure that takes do not exceed what is authorized by 
the IHA. In addition, following the completion of the survey, Apache 
will submit a draft report on all activities and monitoring results to 
the Office of Protected Resources within 90 days of the completion of 
the Apache survey.
    Comment 6: Environmental NGOs commented that NMFS should not rely 
on its regulatory definition of ``small numbers'' that was found to be 
improper by a U.S. District Court in Natural Resources Defense Council 
v. Evans, 279 F.Supp. 2d 1129 (N.D. Ca. 2003). They also commented that 
the take of 30 Cook Inlet beluga whales is not a ``small number'' for 
such an isolated, endangered population.
    Response: NMFS does not rely on the 1982 regulatory definition of 
small numbers for its incidental take authorizations. Instead, NMFS 
addresses ``small numbers'' in terms relative to the stock or 
population size. Apache requested, and NMFS authorizes, the take of 30 
Cook Inlet beluga whales by Level B harassment, which represents about 
10 percent of the population if one assumes that each take is a 
separate individual animal. In addition, the percentage would be even 
lower if animals make minor course adjustments to avoid the approaching 
seismic survey area in a manner that does not result in take at all. 
Additionally, the requirement to cease operating when cow-calf pairs or 
groups of 5 or more animals enter the 160dB zone is likely to further 
reduce the number of individuals taken. NMFS has determined that the 
small numbers requirement has been satisfied for this IHA. The status 
of the Cook Inlet beluga population (i.e., the fact that it is an 
isolated, endangered population) has been carefully considered in NMFS' 
negligible impact analysis.
    Comment 7: Environmental NGOs commented that NMFS's assumption that 
marine mammals will not be harassed by sounds below 160 dB re 1 
[micro]Pa (rms) is arbitrary and not supported by science. The NGOs 
support their comment by providing as an example the sensitivity of 
harbor porpoises to noise and NMFS's use of 120 dB as a threshold when 
authorizing take incidental to Navy sonar activities. In addition, the 
commenters refer to a recent decision document related to seismic 
surveys in the Chukchi Sea where NMFS imposed a 120 dB safety zone for 
aggregations of bowhead whales.
    Response: NMFS does not agree with the commenter's assessment of 
the 160 dB threshold. NMFS uses 160 dB for most species in most cases 
based on the best available information. NMFS established the current 
Level B harassment (sub-injurious) thresholds for underwater sound 
sources (except explosives and tactical active sonar) based on measured 
avoidance responses observed in whales in the wild. Specifically, the 
160 dB threshold was derived from data for mother-calf pairs of 
migrating gray whales (Malme et al., 1983, 1984) and bowhead whales 
(Richardson et al., 1985, 1986) responding to seismic airguns (e.g., 
impulsive sound source). This threshold has been applied to a variety 
of activities, such as seismic surveys and impact pile driving.
    Regarding the 120 dB threshold for the onset of behavioral 
harassment for harbor porpoises by Navy sonar activities, that 
threshold is limited to exposure to mid- and high-frequency sonar 
signals, which are defined as sound with dominant frequency at 1-10 kHz 
and above 10 kHz, respectively. In contrast, sounds produced during 
marine seismic surveys have most of their energy concentrated at the 
lower end of the frequency spectrum, which is largely outside of the 
frequency range where harbor porpoises have the highest sensitivity 
(Anderson 1970; Kastelein et al. 2002). Harbor porpoises are considered 
sensitive species that respond to active sonar signals at lower 
received levels than other species in a manner that NMFS considers 
Level B harassment. Therefore, NMFS believes that it is scientifically 
justifiable to use received level at 120 dB as the threshold for 
behavioral harassment for harbor porpoises exposed to mid- and high-
frequency Navy sonar, but it is not appropriate to use this received 
level as the threshold for behavioral harassment for harbor porpoises 
or other marine mammal species when exposed to sounds from seismic 
surveys. NMFS continues to believe that the 160 dB threshold is 
appropriate for determining the level of take of marine mammals by

[[Page 27723]]

Level B harassment for impulse noise (such as from airguns).
    Separately, the comment about mitigation measures for aggregations 
of bowheads is incorrect. NMFS has included shutdown measures at the 
160 dB threshold for aggregations of bowheads in the Arctic during 
seismic surveys, but not 120 dB. Moreover, this measure was required to 
ensure no unmitigable adverse impact on the availability of bowheads 
for subsistence uses, pursuant to the MMPA, not strictly as a means to 
effect the least practicable impact on bowhead whales. Bowhead whales, 
hunted by Alaska Natives, are low-frequency hearing specialists (unlike 
any of the species in Cook Inlet) and the frequency of seismic airguns 
falls within the frequency range of their highest sensitivity. During 
migration, they may respond to received levels below 160 dB in a manner 
that could potentially interfere with a subsistence hunt (e.g., causing 
a minor deflection in their migratory path), but which NMFS would not 
consider harassment. In addition, these minor course changes occurred 
during migration and have not been seen at other times of the year and 
during other activities.
    Comment 8: Environmental NGOs commented that because the status of 
Cook Inlet beluga whales is so tenuous, NMFS cannot conclude that the 
activities that will harass a significant portion of the population 
will have no more than a negligible effect on the stock.
    Response: NMFS took into account the status of Cook Inlet beluga 
whales as well as other factors in making its negligible impact 
determination, as explained in this Federal Register Notice. NMFS used 
the best scientific information to support the analyses for its 
preliminary determination in its proposed IHA notice (76 FR 58473, 
September 21, 2011) and its final determination presented in this 
Federal Register notice.
    Comment 9: Environmental NGOs commented that NMFS cannot make a 
negligible impact finding because the agency has failed to address the 
likely impact of a large scale stranding event caused by Apache's 
activities.
    Response: Marine mammals close to underwater detonations of high 
explosive can be killed or severely injured, and the auditory organs 
are especially susceptible to injury (Ketten et al. 1993; Ketten 1995). 
Air gun pulses are less energetic and their peak amplitudes have slower 
rise times. To date, there is no evidence that serious injury, death, 
or stranding by marine mammals can occur from exposure to airgun 
pulses, even in the case of large airgun arrays.
    However, in numerous past IHA notices for seismic surveys, 
commenters have referenced two stranding events allegedly associated 
with seismic activities, one off Baja California and a second off 
Brazil. NMFS has addressed this concern several times, and, without new 
information, does not believe that this issue warrants further 
discussion. For information relevant to strandings of marine mammals, 
readers are encouraged to review NMFS' response to comments on this 
matter found in 69 FR 74905 (December 14, 2004), 71 FR 43112 (July 31, 
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 
2006). In addition, a May- June 2008, stranding of 100-200 melon-headed 
whales (Peponocephala electra) off Madagascar that appears to be 
associated with seismic surveys is currently under investigation (IWC 
2009).
    It should be noted that strandings related to sound exposure have 
not been recorded for marine mammal species in Cook Inlet. NMFS notes 
that beluga whale strandings in Cook Inlet are not uncommon; however, 
these events often coincide with extreme tidal fluctuations (``spring 
tides'') or killer whale sightings (Shelden et al., 2003). No 
strandings or marine mammals in distress were observed during the 2D 
test survey conducted by Apache in March 2011, and none were reported 
by Cook Inlet inhabitants. As a result, NMFS does not expect any marine 
mammals will incur serious injury or mortality in Cook Inlet or strand 
as a result of the proposed seismic survey.
    Comment 10: Environmental NGOs commented that the MMPA's negligible 
impact standard requires NMFS to consider the effects of the proposed 
seismic activities on Cook Inlet beluga whales together with all other 
activities that affect belugas in Cook Inlet and not issuing an 
Environmental Assessment (EA) or Environmental Impact Statement (EIS) 
in advance of proposing to issue an IHA makes it impossible for the 
public to know whether cumulative effects have been properly 
considered.
    Response: Section 101(a)(5)(D) of the MMPA requires NMFS to make a 
determination that the harassment incidental to a specified activity 
will have a negligible impact on the affected species or stocks of 
marine mammals, and will not result in an unmitigable adverse impact on 
the availability of marine mammals for taking for subsistence uses. 
Neither the MMPA nor NMFS' implementing regulations specify how to 
consider other activities and their impacts on the same populations. 
However, consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338, September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into the 
negligible impact analysis via their impacts on the environmental 
baseline (e.g., as reflected in the density/distribution and status of 
the species, population size and growth rate, and ambient noise).
    In addition, cumulative effects were addressed in the Environmental 
Assessment and biological opinion prepared for this action, both of 
which NMFS indicated would be completed prior to the issuance of an IHA 
(76 FR 58473). These documents, as well as the Alaska Marine Stock 
Assessments and the most recent abundance estimate for Cook Inlet 
beluga whales (Hobbs et al. 2011), are part of NMFS' Administrative 
Record for this action, and provided the decision maker with 
information regarding other activities in the action area that affect 
marine mammals, an analysis of cumulative impacts, and other 
information relevant to the determination made under the MMPA.
    Comment 11: Environmental NGOs commented that given the very low 
subsistence take of Cook Inlet beluga whales in recent years, the 
injury or mortality of a single beluga by Apache's activities could 
preclude any subsistence harvest; therefore, NMFS cannot conclude that 
the incidental take does not have ``an unmitigable adverse impact on 
the availability of such species or stock for taking for subsistence 
uses'' by Alaska Natives.
    Response: Unmitigable adverse impact means an impact resulting from 
the specified activity: (1) That is likely to reduce the availability 
of the species to a level insufficient for a harvest to meet 
subsistence needs by: (i) Causing the marine mammal 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. Currently there is no subsistence hunting 
of Cook Inlet belugas authorized (73 FR 60976, October 15, 2008). 
Apache did not request and NMFS does not anticipate, nor is it 
authorizing, any Level A harassment takes of Cook Inlet beluga whales 
or takes by mortality incidental to the seismic surveys. The required 
mitigation and monitoring measures are designed to avoid exposing any 
marine mammals, including Cook Inlet beluga

[[Page 27724]]

whales, to sound levels that may result in injury; therefore, NMFS 
believes that any adverse impact from the specified activity can be 
mitigated. For example, protected species observers will monitor the 
marine mammal exclusion zone while a sound source is active and have 
the authority to require power-downs or shut-downs to ensure that Level 
A harassment takes do not occur. In the unlikely event that marine 
mammals do get exposed to injurious levels of sound, the IHA will 
require Apache to cease work and report the incident to NMFS.
    Comment 12: Environmental NGOs commented that NMFS should 
reconsider allowing Apache to continue seismic surveys during nighttime 
(low light) and other low visibility conditions.
    Response: Section 101(a)(5)(D) of the MMPA requires NMFS to 
prescribe means of effecting the least practicable impact on marine 
mammal species or stocks. With respect to Apache's seismic survey, (1) 
marine mammals would need to be within about 330 m of the 10 cubic inch 
``mitigation'' airgun to be exposed to the 160 dB and within about 33 m 
to be exposed to injurious levels of sound; (2) the approaching airgun 
arrays, source vessels, and support vessels preclude or discourage 
marine mammals from entering the action area by alerting animals to the 
presence of the activity; and (3) the continuous operation of the 
mitigation airgun at night if survey shooting is to occur at night will 
alert marine mammals to the presence of survey vessels in the area, 
which allows them the opportunity to move away before being exposed to 
injurious levels of sound.
    With respect to practicability, NMFS believes that requiring Apache 
to halt seismic surveys during nighttime and other low visibility 
conditions would increase the amount of time it would take Apache to 
complete the survey and may require additional survey vessels to be 
brought into Cook Inlet. As a result, NMFS considers the implementation 
of this recommendation as a mitigation measure to be impracticable for 
both economic and practical reasons.
    However, to further enhance the detection of marine mammals, 
passive acoustic monitoring (PAM) systems will be deployed, if ice 
conditions allow, inside the 180/190 dB safety zone in both the up-
inlet and down-inlet directions. The fixed system will include two 
JASCO Advanced Multichannel Acoustic Recorders that send real-time 
acoustic data via digital UHF radio-broadcast systems to PAM operators 
aboard the M/V Dreamcatcher. If ice is present, the PAM system can be 
deployed from the vessel. The PAM operators use specialized real-time 
detection software and audio playback to detect marine mammal sounds. 
If PAM operators detect a marine mammal vocalizing, they are authorized 
to instruct Apache to initiate a shut-down or power-down of airguns. If 
a shut-down occurs at night, seismic surveys will be suspended until 
the following day and the full safety zone is visible.
    Moreover, as stated in the Federal Register notice proposing the 
IHA, at night, the vessel captains and crews will maintain lookout for 
marine mammals and will order the airgun(s) to be shut down if marine 
mammals are observed in or about to enter the safety radii. As with 
shut-down initiated by acoustic detection of marine mammals at night, 
if a shut down occurs, survey activities will be suspended until the 
following day and will only be resumed if the full safety zone is 
visible. At that point, the ramp-up requirement for airguns and other 
seismic equipment during normal visual conditions is expected to keep 
marine mammals from entering the established safety zones.
    Comment 13: Environmental NGOs commented that NMFS must examine the 
practicability of including additional mitigation measures, such as 
time/area restrictions on the proposed activities, based on marine 
mammal activity and habitat use.
    Response: NMFS considered including time/area restrictions. Beluga 
whales remain in Cook Inlet year-round, but demonstrate seasonal 
movement within the Inlet; in the summer and fall, they concentrate in 
upper Cook Inlet's rivers and bays, but tend to disperse offshore and 
move to mid-Inlet in winter (Hobbs et al., 2005). The available 
information indicates that in the winter months belugas concentrate in 
deeper waters in mid-Inlet past Kalgin Island, with occasional forays 
into the upper inlet, including the upper ends of Knik and Turnagain 
Arms. Their winter distribution does not appear to be associated with 
river mouths, as it is during the warmer months. The spatial dispersal 
and diversity of winter prey are likely to influence the wider beluga 
winter range throughout the mid-Inlet. Apache now expects to commence 
its seismic survey in April, which would coincide with the time of year 
when belugas are dispersed offshore in the mid-Inlet and away from 
river mouths. In the spring, beluga whales are regularly sighted in the 
upper Inlet beginning in late April or early May, coinciding with 
eulachon runs in the Susitna River and Twenty Mile River in Turnagain 
Arm, and well outside of the area where Apache will be conducting 
seismic surveys. Therefore, NMFS believes that the timing and location 
of the seismic survey, as proposed, will avoid areas and seasons that 
overlap with important beluga whale behavioral patterns.
    Comment 14: Environmental NGOs commented that NMFS must resubmit 
the proposed IHA for notice and comment when the results from the sound 
source verification study assessing underwater noise produced on 
explosive detonations onshore become available.
    Response: In the Federal Register notice announcing the proposed 
IHA, NMFS indicated that Apache would be conducting a sound source 
verification (SSV) study to measure in-water noise from the detonation 
of explosives onshore (76 FR 58473, September 21, 2011). The results 
from this study are summarized below and the complete report is posted 
on the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. 
On September 17-18, 2011, two acoustic teams conducted the SSV test to 
ensure that marine mammals would not be exposed to underwater received 
levels exceeding NMFS' threshold for Level B harassment during the 
proposed seismic survey. The SSV test consisted of a total of seven 
shot locations beginning in the mudflats, three locations in the 
lowlands and spaced every half mile for 4 miles inland, for a total of 
24 holes. Each location had a 1 kg charge buried at 25 ft, a 2 kg 
charge buried at 25 ft, and a 4 kg charge buried at 35 ft. To monitor 
the explosions onshore, three JASCO Ocean Bottom Hydrophones (OBHs) 
were deployed at 3 km, 6 km, and 10 km from the last shothole on the 
testline two JASCO vessel-based real-time acoustic monitoring and data 
logging stations were deployed from vessels located at 3 km and 6 km 
from the last shothole on the testline, and one 4-channel particle 
velocity and acceleration measurement system was deployed from a vessel 
approximately 1 km from the last shothole on the testline. The results 
were analyzed from the three loudest shots recorded on the OBH and 
vessel-based data logging systems located 3 km from the shot nearest 
the vessels. The OBH was at a depth of approximately 30 m, 1.5 m above 
the seafloor, and the over-the-side system was at a depth of 2 m. In 
general, the sound levels measured by the over-the-side hydrophone were 
lower than those measured by the OBH; however, this was expected 
because low-frequency sounds are strongly attenuated near the sea 
surface due to the proximity of the pressure-release boundary. The OBH 
at 3 km recorded

[[Page 27725]]

received levels between 142-144 dB re 1 [micro]Pa (0-Peak SPL) and 
between 130-132 dB re 1 [micro]Pa\2\/s SEL. The over-the-side system at 
3 km recorded received levels of between 117-124 dB re 1 [micro]Pa (0-
Peak SPL) and between 106-114 dB re 1 [micro]Pa\2\/s SEL. These results 
are well below the NMFS criterion of 160 dB and do not constitute an 
activity that would result in the incidental take of marine mammals or 
require inclusion in Apache's IHA request.
    Description of Marine Mammals in the Area of the Specified Activity
    The marine mammal species under NMFS's jurisdiction that could 
occur near operations in Cook Inlet include three cetacean species: 
beluga whale (Delphinapterus leucas), killer whale (Orcinus orca), and 
harbor porpoise (Phocoena phocoena), and two pinniped species: harbor 
seal (Phoca vitulina richardsi) and Steller sea lions (Eumetopias 
jubatus). The marine mammal species that is likely to be encountered 
most widely (in space and time) throughout the period of the planned 
survey is the harbor seal.
    Of the five marine mammal species likely to occur in the proposed 
marine survey area, only Cook Inlet beluga whales and Steller sea lions 
are listed as endangered under the ESA (Steller sea lions are listed as 
two distinct population segments (DPSs), an eastern and a western DPS; 
the relevant DPS in Cook Inlet is the western DPS). These species are 
also designated as ``depleted'' under the MMPA. Despite these 
designations, Cook Inlet beluga whales and the western DPS of Steller 
sea lions have not made significant progress towards recovery. The Cook 
Inlet population of beluga whales has been decreasing at a rate of 1.5 
percent annually for nearly a decade (Allen and Angliss, 2010). With 
respect to Steller sea lions, results of aerial surveys conducted in 
2008 (Fritz et al., 2008) confirmed that the recent (2004-2008) overall 
trend in the western population of adult and juvenile Steller sea lions 
in Alaska is stable or possibly in decline; however, there continues to 
be considerable regional variability in recent trends. Pursuant to the 
ESA, critical habitat has been designated for Cook Inlet beluga whales 
and Steller sea lions. The proposed action falls within critical 
habitat designated in Cook Inlet for beluga whales, but is not within 
critical habitat designated for Steller sea lions. The portion of 
beluga whale critical habitat--identified as Area 2--where the seismic 
survey will occur is located south of the Area 1 critical habitat where 
belugas are particularly vulnerable to impacts due to their high 
seasonal densities and the biological importance of the area for 
foraging, nursery, and predator avoidance. Area 2 is largely based on 
dispersed fall and winter feeding and transit areas in waters where 
whales typically appear in smaller densities or deeper waters (76 FR 
20180, April 11, 2011).

Cetaceans

    Beluga Whales--Cook Inlet beluga whales reside in Cook Inlet year-
round although their distribution and density change seasonally. 
Factors that are likely to influence beluga whale distribution within 
the inlet include prey availability, predation pressure, sea-ice cover, 
and other environmental factors, reproduction, sex and age class, and 
human activities (Rugh et al., 2000; NMFS, 2008). Seasonal movement and 
density patterns as well as site fidelity appear to be closely linked 
to prey availability, coinciding with seasonal salmon and eulachon 
concentrations (Moore et al., 2000). For example, during spring and 
summer, beluga whales are generally concentrated near the warmer waters 
of river mouths where prey availability is high and predator occurrence 
is low (Huntington 2000; Moore et al., 2000). Beluga whales use several 
areas of the upper Cook Inlet for repeated summer and fall feeding. The 
primary hotspots for beluga feeding include the Big and Little Susitna 
rivers, Eagle Bay to Eklutna River, Ivan Slough, Theodore River, Lewis 
River, and Chickaloon River and Bay (NMFS, 2008). Availability of prey 
species appears to be the most influential environmental variable 
affecting Cook Inlet beluga whale distribution and relative abundance 
(Moore et al., 2000). The patterns and timing of eulachon and salmon 
runs have a strong influence on beluga whale feeding behavior and their 
seasonal movements (Nemeth et al., 2007; NMFS 2008). The presence of 
prey species may account for the seasonal changes in beluga group size 
and composition (Moore et al., 2000).
    Aerial and vessel-based monitoring conducted by Apache during the 
March 2011 2D test program in Cook Inlet reported 33 beluga sightings. 
One of the sightings was of a large group (~25 individuals on March 27, 
2011) of feeding/milling belugas near the mouth of the Drift River. 
Also on March 27, 2011, PSOs onboard the M/V Dreamcatcher reported a 
group of seven beluga whales approximately 0.5 nm from the vessel. 
Land-based PSOs were able to observe this group of beluga whales for 
approximately 2.5 hrs. A single beluga whale was observed near the 
mouth of the Drift River by the aerial-based monitors on March 28, 
2011, prior to the seismic ramp-up period. If belugas are present 
during the late summer/early fall, they are more likely to occur in 
shallow areas near river mouths in upper Cook Inlet. As explained below 
in the section on Estimated Takes, expected densities were calculated 
from the annual aerial surveys conducted by NMFS between 2000 and 2010 
(Rugh et al., 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007; Shelden 
et al., 2008, 2009, 2010). In response to the Commission's 
recommendation (see Comment 2), Apache recalculated beluga 
whale densities for non-river mouths. Those updated densities are 
presented in Table 3.
    Killer Whales--In general, killer whales are rare in upper Cook 
Inlet, where transient killer whales are known to feed on beluga whales 
and resident killer whales are known to feed on anadromous fish 
(Shelden et al., 2003). The availability of these prey species largely 
determines the likeliest times for killer whales to be in the area. 
Between 1993 and 2004, 23 sightings of killer whales were reported in 
the lower Cook Inlet during aerial surveys by Rugh et al. (2005). 
Surveys conducted over a span of 20 years by Shelden et al. (2003) 
reported 11 sightings in upper Cook Inlet between Turnagain Arm, 
Susitna Flats, and Knik Arm. No killer whales were spotted during 
recent surveys by Funk et al. (2005), Ireland et al. (2005), Brueggeman 
et al. (2007a, 2007b, 2008), or Prevel Ramos et al. (2006, 2008). 
Eleven killer whale strandings have been reported in Turnagain Arm, six 
in May 1991 and five in August 1993. Therefore, few killer whales, if 
any, are expected to approach or be in the vicinity of the action area.
    Harbor Porpoise--The most recent estimated maximum density for 
harbor porpoises in Cook Inlet is 7.2 per 1,000 km\2\ (Dahlheim et al., 
2000) indicating that only a small number use Cook Inlet. Harbor 
porpoise have been reported in lower Cook Inlet from Cape Douglas to 
the West Foreland, Kachemak Bay, and offshore (Rugh et al., 2005). 
Small numbers of harbor porpoises have been consistently reported in 
upper Cook Inlet between April and October, except for a recent survey 
that recorded higher than usual numbers. Prevel Ramos et al. (2008) 
reported 17 harbor porpoises from spring to fall 2006, while other 
studies reported 14 in the spring of 2007 (Brueggeman et al., 2007) and 
12 in the fall (Brueggeman et al., 2008). During the spring and fall of 
2007, 129 harbor porpoises were reported between Granite Point and the 
Susitna River; however, the reason for the higher numbers of harbor 
porpoise in the upper Cook Inlet remains unclear and the

[[Page 27726]]

disparity with the results of past sightings suggests that it may be an 
anomaly. The spike in reported sightings occurred in July, which was 
followed by sightings of 79 harbor porpoises in August, 78 in 
September, and 59 in October, 2007. It is important to note that the 
number of porpoises counted more than once was unknown, which suggests 
that the actual numbers are likely smaller than those reported. On the 
other hand, recent passive acoustic research in Cook Inlet by the 
Alaska Department of Fish and Game and the National Marine Mammal 
Laboratory have indicated that harbor porpoises occur in the area more 
frequently than previously thought, particularly in the West Foreland 
area in the spring (NMFS 2011); however overall numbers are still 
unknown at this time.

Pinnipeds

    Harbor Seals--Harbor seals inhabit the coastal and estuarine waters 
of Cook Inlet. In general, harbor seals are more abundant in lower Cook 
Inlet than in upper Cook Inlet, but they do occur in the upper inlet 
throughout most of the year (Rugh et al., 2005). Harbor seals are non-
migratory; their movements are associated with tides, weather, season, 
food availability, and reproduction. The major haulout sites for harbor 
seals are located in lower Cook Inlet and their presence in the upper 
inlet coincides with seasonal runs of prey species. For example, harbor 
seals are commonly observed along the Susitna River and other 
tributaries along upper Cook Inlet during the eulachon and salmon 
migrations (NMFS, 2003). During aerial surveys of upper Cook Inlet in 
2001, 2002, and 2003, harbor seals were observed 24 to 96 km south-
southwest of Anchorage at the Chickaloon, Little Susitna, Susitna, 
Ivan, McArthur, and Beluga Rivers (Rugh et al., 2005). During the 2D 
test program in March 2011, two harbor seals were observed by vessel-
based PSOs. On March 25, 2011, one harbor seal was observed 
approximately 400 m from the M/V Miss Diane. At the time of the 
observation, the vessel was operating the positioning pinger and PSOs 
instructed the operator to implement a shut-down. The pinger was shut 
down for 30 minutes while PSO monitored the area and re-started the 
device when the animal was not sighted again during the 30 minute site 
clearing protocol. No unusual behaviors were reported during the time 
the animal was observed. The second harbor seal was observed on March 
26, 2011, by vessel-based PSO onboard the M/V Dreamcatcher 
approximately 4260 m from the source vessel, which was operating the 10 
in\3\ airgun at the time. The animal was well outside of the 160 dB 
zone (330 m for the 10 in\3\ airgun) and no unusual behaviors were 
observed. The closest haulout site to the action area is located on 
Kalgin Island, which is approximately 22 km away from the McArthur 
River.
    Steller Sea Lion--Two separate stocks of Steller sea lions are 
recognized within U.S. waters: an eastern DPS, which includes animals 
east of Cape Suckling, Alaska; and a western DPS, which includes 
animals west of Cape Suckling (NMFS, 2008). Individuals in Cook Inlet 
are considered part of the western DPS, which is listed as endangered 
under the ESA. Steller sea lions primarily occur in lower, rather than 
upper Cook Inlet and are rarely sighted north of Nikiski on the Kenai 
Peninsula. Haul-outs and rookeries are located near Cook Inlet at Gore 
Point, Elizabeth Island, Perl Island, and Chugach Island (NMFS, 2008). 
No Steller seal lion haul-outs or rookeries are located in the vicinity 
of the proposed seismic survey. Furthermore, no sightings of Steller 
sea lions were reported by Apache during the 2D test program in March 
2011. Although Apache has requested takes of Steller sea lions, it is 
unlikely that any Steller sea lions would occur in the action area 
during seismic survey operations.
    Apache's application contains additional information on the status, 
distribution, seasonal distribution, and abundance of each of the 
affected species under NMFS' jurisdiction mentioned in this document. 
Please refer to the application for that information (see ADDRESSES). 
Additional information can also be found in the NMFS Stock Assessment 
Reports (SAR). The Alaska 2010 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2010.pdf.

Potential Effects of the Airgun Sounds on Marine Mammals

    The effects of sounds from airgun pulses might include one or more 
of the following: tolerance, masking of natural sounds, behavioral 
disturbance, temporary or permanent hearing impairment, or non-auditory 
physical or physiological effects (Richardson et al., 1995; Gordon et 
al., 2004; Nowacek et al., 2007; Southall et al., 2007). As outlined in 
previous NMFS documents, the effects of noise on marine mammals are 
highly variable. The Notice of Proposed IHA (76 FR 58473, September 21, 
2011) included a discussion of the effects of airguns on marine 
mammals, which is not repeated here. That discussion took into 
consideration the monitoring and mitigation measure proposed by Apache 
and NMFS. No cases of temporary threshold shift (TTS) are expected as a 
result of Apache's activities given the small size of the source, the 
strong likelihood that marine mammals would avoid the approaching 
airguns (or vessels) before being exposed to levels high enough for 
there to be any possibility of TTS, and the mitigation measures 
required to be implemented during the survey described later in this 
document. Based on the fact that the sounds produced by Apache's 
operations are unlikely to cause TTS in marine mammals, it is extremely 
unlikely that permanent hearing impairment would result. No injuries or 
mortalities are anticipated as a result of Apache's operations, and 
none are authorized to occur. Only Level B harassment is anticipated as 
a result of Apache's activities.

Potential Effects From Pingers on Marine Mammals

    Active acoustic sources other than the airguns have been proposed 
for Apache's 2012 seismic survey in Cook Inlet. The specifications for 
the pingers (source levels and frequency ranges) were provided in the 
Notice of Proposed IHA (76 FR 58473, September 21, 2011). In general, 
the potential effects of this equipment on marine mammals are similar 
to those from the airguns, except the magnitude of the impacts is 
expected to be much less due to the lower intensity of the source.

Potential Effects From Vessels and Vessel Noise on Marine Mammals

    Vessel activity and noise associated with vessel activity will 
temporarily increase in the action area during Apache's seismic survey 
as a result of the operation of eight vessels. To minimize the effects 
of vessels and noise associated with vessel activity, Apache will 
follow NMFS' Marine Mammal Viewing Guidelines and Regulations and will 
alter heading or speed if a marine mammal gets too close to a vessel. 
In addition, vessels will be operating at slow speed (2-4 knots) when 
conducting surveys and in a purposeful manner to and from work sites in 
as direct a route as possible. Marine mammal monitoring observers and 
passive acoustic devices will alert vessel captains as animals are 
detected to ensure safe and effective measures are applied to avoid 
coming into direct contact with marine mammals. Therefore, NMFS neither 
anticipates nor authorizes takes of marine mammals from ship strikes.
    Odontocetes, such as beluga whales, killer whales, and harbor 
porpoises, often show tolerance to vessel activity;

[[Page 27727]]

however, they may react at long distances if they are confined by ice, 
shallow water, or were previously harassed by vessels (Richardson, 
1995). Beluga whale response to vessel noise varies greatly from 
tolerance to extreme sensitivity depending on the activity of the whale 
and previous experience with vessels (Richardson, 1995). Reactions to 
vessels depends on whale activities and experience, habitat, boat type, 
and boat behavior (Richardson, 1995) and may include behavioral 
responses, such as altered headings or avoidance (Blane and Jaakson, 
1994; Erbe and Farmer, 2000); fast swimming; changes in vocalizations 
(Lesage et al., 1999; Scheifele et al., 2005); and changes in dive, 
surfacing, and respiration patterns.
    There are few data published on pinniped responses to vessel 
activity, and most of the information is anecdotal (Richardson, 1995). 
Generally, sea lions in water show tolerance to close and frequently 
approaching vessels and sometimes show interest in fishing vessels. 
They are less tolerant when hauled out on land; however, they rarely 
react unless the vessel approaches within 100-200 m (330-660 ft; 
reviewed in Richardson, 1995).
    The addition of eight vessels and noise due to vessel operations 
associated with the seismic survey would not be outside the present 
experience of marine mammals in Cook Inlet, although levels may 
increase locally. Given the large number of vessels in Cook Inlet and 
the apparent habituation to vessels by Cook Inlet beluga whales and the 
other marine mammals that may occur in the area, vessel activity and 
noise is not expected to have effects that could cause significant or 
long-term consequences for individual marine mammals or their 
populations.

Potential Effects From Aircraft Noise on Marine Mammals

    Apache plans to utilize the crew helicopter to conduct aerial 
surveys near river mouths in order to identify locations or 
congregations of beluga whales and other marine mammals prior to the 
commencement of operations. The helicopter will not be used every day, 
but will be used for surveys near river mouths. Aerial surveys will fly 
at an altitude of 305 m (1,000 ft) when practicable and weather 
conditions permit. In the event of a marine mammal sighting, aircraft 
will try to maintain a radial distance of 457 m (1,500 ft) from the 
marine mammal(s). Aircraft will avoid approaching marine mammals from 
head-on, flying over or passing the shadow of the aircraft over the 
marine mammals.
    Studies on the reactions of cetaceans to aircraft show little 
negative response (Richardson et al., 1995). In general, reactions 
range from sudden dives and turns and are typically found to decrease 
if the animals are engaged in feeding or social behavior. Whales with 
calves or in confined waters may show more of a response. Generally 
there has been little or no evidence of marine mammals responding to 
aircraft overflights when altitudes are at or above 1,000 ft, based on 
three decades of flying experience in the Arctic (NMFS, unpublished 
data). Based on long-term studies that have been conducted on beluga 
whales in Cook Inlet since 1993, NMFS expect that there will be no 
effects of this activity on beluga whales or other cetaceans. No change 
in beluga swim directions or other noticeable reactions have been 
observed during the Cook Inlet aerial surveys flown from 600 to 800 ft. 
(e.g., Rugh et al., 2000). By applying the operational requirements 
discussed above, sound levels underwater are not expected to reach 
NMFS' harassment thresholds.
    The majority of observations of pinnipeds reacting to aircraft 
noise are associated with animals hauled out on land or ice. There are 
very little data describing the reactions of pinnipeds in water to 
aircraft (Richardson et al., 1995). In the presence of aircraft, 
pinnipeds hauled out for pupping or molting generally became alert and 
then rushed or slipped (when on ice) into the water. Stampedes often 
result from this response and may increase pup mortality due to 
crushing or an increased rate of pup abandonment. The greatest 
reactions from hauled out pinnipeds were observed when low flying 
aircraft passed directly above the animal(s) (Richardson et al., 1995). 
Although noise associated with aircraft activity could cause hauled out 
pinnipeds to rush into the water, there are no known haul out sites in 
the vicinity of the survey site.
    Therefore, the operation of aircraft during the seismic survey is 
not expected to have effects that could cause significant or long-term 
consequences for individual marine mammals or their populations. To 
minimize the noise generated by aircraft, Apache will follow NMFS' 
Marine Mammal Viewing Guidelines and Regulations found at http://www.alaskafisheries.noaa.gov/protectedresources/mmv/guide.htm.

Anticipated Effects on Marine Mammal Habitat

    NMFS included a detailed discussion of the potential effects of 
this action on marine mammal habitat, including physiological and 
behavioral effects on marine fish and invertebrates, in the notice of 
the proposed IHA (76 FR 58473, September 21, 2011). While NMFS 
anticipates that the specified activity may result in marine mammals 
avoiding certain areas due to temporary ensonification, this impact to 
habitat is temporary and site-specific, which NMFS considered as 
behavioral modification. The main impact associated with the activity 
would be temporarily elevated noise levels and the associated direct 
effects on marine mammals.

Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses.
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, Apache and/or its designees will 
implement the following mitigation measures for marine mammals:

 (1) Operation of Mitigation Airgun at Night

    Apache proposes to conduct both daytime and nighttime operations. 
Nighttime operations will only be initiated if a mitigation airgun 
(typically the 10 in\3\) has been continuously operational from the 
time that PSO monitoring has ceased for the day. The mitigation airgun 
will operate on a longer duty cycle than the full airgun arrays, firing 
every 30-45 seconds. Seismic activity will not ramp up from an extended 
shut-down (i.e., when the airgun has been down with no activity for at 
least 10 minutes) during nighttime operations and survey activities 
will be suspended until the following day because dedicated PSOs will 
not be on duty and any unseen animals may be exposed to injurious 
levels of sound from the full array. At night, the vessel captain and 
crew will maintain lookout for marine mammals and will order the 
airgun(s) to be shut down if marine mammals are observed in or about to 
enter the established safety radii.

(2) Safety and Disturbance Zones

    NMFS mitigation or shutdown ``safety radii'' for limiting marine 
mammal exposure to impulse sources typically

[[Page 27728]]

correspond to the distances within which received sound levels are 
>=180 dBrms re 1 [mu]Pa for cetaceans and >=190 
dBrms re 1 [mu]Pa for pinnipeds. These safety criteria are 
based on an assumption that SPLs received at levels lower than these 
will not injure these animals or impair their hearing abilities. 
Disturbance or behavioral effects to marine mammals from underwater 
sound may occur from exposure to sound at lower SPLs, at distances 
greater than the safety radii (Richardson et al., 1995). The 
disturbance zone is defined as the area between the 180/190 dB 
threshold and the 160 dB threshold where NMFS has determined that 
harassment in the form of behavioral disturbance may occur.
    The proposed survey will use airgun sources composed of two 2400 
in\3\ airguns, a single 440 in\3\ airgun, and a single 10 in\3\ airgun. 
Safety and disturbance radii for the sound levels produced by the 
planned airgun configurations and pinger have been estimated (see Table 
1) and will be used for mitigation purposes during the seismic survey 
activities.

 Table 1--Estimated Distances to Sound Thresholds (Apache Will Conduct a
  Sound Source Verification Study To Determine the Actual Distances to
                         These Threshold Zones)
------------------------------------------------------------------------
            Source                 190 dB        180 dB        160 dB
------------------------------------------------------------------------
Pinger.......................  1 m            3 m           25 m
10 cui Airgun................  10 m           33 m          330 m
440 cui Airgun...............  NA             NA            NA
2,400 cui airgun (nearshore).  0.51 km        1.42 km       6.41 km
2,400 cui airgun (offshore)..  1.18 km        0.98 km       4.89 km
------------------------------------------------------------------------

    In addition to the marine mammal monitoring radii described above, 
pursuant to Alaska Department of Fish and Game restrictions, there will 
be a 1.6 km setback of sound source points from the mouths of any 
anadromous streams.
    Apache also plans to use dedicated vessels to deploy and retrieve 
the nodal recording system. Sounds produced by the vessels are not 
expected to exceed 180 dB (rms). Therefore, mitigation related to 
acoustic impacts from these activities is not expected to be necessary.

 (3) Power-downs

    A power-down for mitigation purposes is the immediate reduction in 
the number of operating airguns such that the radii of the 190 dB rms 
and 180 dB rms zones are decreased to the extent that observed marine 
mammal(s) are not in the applicable safety zone of the full array. 
During a power-down, one airgun, typically the 10 in\3\, continues 
firing. Operation of the 10 in\3\ airgun decreases the safety radii to 
10 m, 33 m, and 330 m for the 190 dB, 180 dB, and 160 dB zones, 
respectively. The continued operation of one airgun is intended to (a) 
alert marine mammals to the presence of the survey vessel in the area, 
and (b) retain the option of initiating a ramp up to full operations 
under poor visibility conditions (including nighttime).
    The array will be immediately powered down whenever a marine mammal 
is sighted approaching close to or within the applicable safety zone of 
the full array, but is outside the applicable safety zone of the single 
mitigation airgun. Likewise, if a mammal is already within the safety 
zone when first detected, the airguns will be powered down immediately. 
If a marine mammal is sighted within or about to enter the applicable 
safety zone of the single mitigation airgun, it too will be shut down 
(see following section).
    Following a power-down, operation of the full airgun array will not 
resume until the marine mammal has cleared the safety zone applicable 
to the full array. The animal will be considered to have cleared the 
safety zone if it
     Is visually observed to have left the safety zone of the 
full array, or
     Has not been seen within the zone for 15 min in the case 
of pinnipeds or small odontocetes (e.g., Steller sea lion, harbor 
seals, or harbor porpoises), or
     Has not been seen within the zone for 30 min in the case 
of large odontocetes (e.g., killer whales or beluga whales).

(4) Shut-downs

    The operating airgun(s) will be shut down completely if a marine 
mammal approaches or enters the safety radius and a power-down is not 
practical or adequate to reduce exposure to less than 190 or 180 dB 
rms, as appropriate. In most cases, this means the mitigation airgun 
will be shut down completely if a marine mammal approaches or enters 
the estimated safety radius for the single 10 in\3\ airgun while it is 
operating during a power down. Airgun activity will not resume until 
the marine mammal has cleared the safety radius. The animal will be 
considered to have cleared the safety radius as described above under 
power down procedures.

 (5) Ramp Ups

    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of airguns firing until the full volume is achieved. The purpose 
of a ramp-up (or ``soft start'') is to ``warn'' undetected cetaceans 
and pinnipeds in the vicinity of the airguns and to provide the time 
for them to move far enough away from the airguns to avoid any 
potential injury or impairment of their hearing abilities.
    During the proposed seismic survey, the seismic operator will ramp 
up the airgun array slowly. NMFS requires the rate of ramp-up to be no 
more than 6 dB per 5-minute period. Ramp-up is used at the start of 
airgun operations, after a power- or shut-down, and after any period of 
greater than 10 minutes in duration without airgun operations (i.e., 
extended shutdown).
    A full ramp up after a shut down will not begin until there has 
been a minimum of 30 minutes of observation of the safety zone by PSOs 
to assure that no marine mammals are present. The entire safety zone 
must be visible during the 30-minute lead-in to a full ramp up. If the 
entire safety zone is not visible, then ramp up from a cold start 
cannot begin. If a marine mammal(s) is sighted within the safety zone 
during the 30-minute watch prior to ramp up, ramp up will be delayed 
until the marine mammal(s) is sighted outside of the safety zone or the 
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for 
small odontocetes and pinnipeds (e.g. harbor porpoises, harbor seals, 
and Steller sea lions), or 30 minutes for large odontocetes (e.g., 
killer whales and beluga whales).

(6) Speed and Course Alterations

    If a marine mammal is detected outside the applicable safety radius 
and, based on its position and the relative motion, is likely to enter 
the safety

[[Page 27729]]

radius, changes of the vessel's speed and/or direct course will be 
considered if this does not compromise operational safety. For marine 
seismic surveys using large arrays, course alterations are not 
typically possible. However, for the smaller airgun arrays planned 
during the proposed site surveys, such changes may be possible. After 
any such speed and/or course alteration is begun, the marine mammal 
activities and movements relative to the survey vessel will be closely 
monitored to ensure that the marine mammal does not approach within the 
relevant safety radius. If the mammal appears likely to enter the 
safety radius, further mitigative actions will be taken, including a 
power down or shut down of the airgun(s).

Additional Mitigation Measures Proposed by NMFS

    Besides Apache's proposed mitigation measures discussed above, NMFS 
is requiring the following additional protective measures for beluga 
whale cow-calf pairs and aggregations of whales. This measure is 
designed to avoid exposing young animals to sounds levels which they 
may have never previously experienced and prevent the potential 
separation of mothers from their calves. In addition, because species 
like killer and beluga whales often travel in groups, the added 
protective measures for aggregations will avoid exposing groups of 
whales, which often contain calves, to harassment sounds levels 
produced during seismic surveys. Specifically, a 160-dB disturbance 
monitoring zone will be established and monitored in Cook Inlet during 
all seismic surveys. Whenever an aggregation of beluga whales or killer 
whales (five or more whales of any age/sex class) or a beluga cow-calf 
pair are observed approaching or within the 160-dB disturbance zone 
around the survey operations, the survey activity will not commence or 
will shut down, until they are no longer present within the 160-dB 
disturbance zone of seismic surveying operations.
    Furthermore, NMFS requires the following measures in the IHA:
    (1) All vessels will reduce speed when within 300 yards (274 m) of 
any whale, and those vessels capable of steering around such groups 
should do so. Vessels may not be operated in such a way as to separate 
members of a group of whales from other members of the group;
    (2) Avoid multiple changes in direction and speed when within 300 
yards (274 m) of whales; and
    (3) When weather conditions require, such as when visibility drops, 
support vessels must adjust speed (increase or decrease) and direction 
accordingly to avoid the likelihood of injury to whales.

Mitigation Conclusions

    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and considered a range of other measures in the context of 
ensuring that NMFS prescribes the means of effecting the least 
practicable impact on the affected marine mammal species and stocks and 
their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
     The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals;
     The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
     The practicability of the measure for applicant 
implementation.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means of effecting the least 
practicable impact on marine mammal species or stocks and their 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.

Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking''. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the proposed action area.

Monitoring Measures

    Apache will provide marine mammal monitoring to implement the 
mitigation measures that require real-time monitoring.

(1) Visual Vessel-Based Monitoring

    Vessel-based monitoring for marine mammals will be done by 
experienced PSOs throughout the period of marine survey activities. 
PSOs will monitor the occurrence and behavior of marine mammals near 
the survey vessel during all daylight periods before, during, and after 
survey operations and during most daylight periods when airgun 
operations are not occurring. PSO duties will include watching for and 
identifying marine mammals, recording their numbers, distances, and 
reactions to the survey operations, and documenting takes incidental to 
the specified activity.
    A sufficient number of PSOs will be required onboard the survey 
vessels to meet the following criteria: (1) 100 percent monitoring 
coverage during all periods of survey operations in daylight; (2) 
maximum of 4 consecutive hours on watch per PSO; and (3) maximum of 12 
hours of watch time per day per PSO.
    PSO teams will consist of experienced field biologists. An 
experienced field crew leader will supervise the PSO team onboard the 
survey vessel. Apache currently plans to have PSOs aboard the three 
vessels: the two source vessels (M/V Peregrine Falcon and M/V Arctic 
Wolf) and one support vessel (M/V Dreamcatcher). Two PSOs will be on 
the source vessels and two PSOs will be on the support vessel to 
observe the safety and disturbance zones. When marine mammals are about 
to enter or are sighted within designated safety zones, airgun or 
pinger operations will be powered down (when applicable) or shut down 
immediately. The vessel-based observers will watch for marine mammals 
during all periods when sound sources are in operation and for a 
minimum of 30 minutes prior to the start of airgun or pinger operations 
after an extended shut down.
    Crew leaders and most other biologists serving as observers will be 
individuals with experience as observers during seismic surveys in 
Alaska or other areas in recent years.
    The observer(s) will watch for marine mammals from the best 
available vantage point on the source and support vessels, typically 
the flying bridge. The observer(s) will scan systematically with the 
unaided eye and 7x50 reticle binoculars. Laser range finders will be 
available to assist with estimating distance. Personnel on the bridge 
will assist the observer(s) in watching for marine mammals.
    All observations will be recorded in a standardized format. Data 
will be entered into a custom database using a notebook computer. The 
accuracy of the data will be verified by computerized validity data 
checks as the data are entered and by subsequent manual checks of the 
database. These procedures will allow for initial summaries of the data 
to be prepared during and shortly after the completion of the field 
program, and will facilitate transfer of the data to statistical, 
geographical, or other programs for future processing and achieving. 
When

[[Page 27730]]

a mammal sighting is made, the following information about the sighting 
will be recorded:
    (A) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from the PSO, apparent reaction to 
activities (e.g., none, avoidance, approach, paralleling, etc.), 
closest point of approach, and behavioral pace;
    (B) Time, location, speed, activity of the vessel, sea state, ice 
cover, visibility, and sun glare; and
    (C) The positions of other vessel(s) in the vicinity of the PSO 
location.
    The ship's position, speed of support vessels, and water 
temperature, water depth, sea state, ice cover, visibility, and sun 
glare will also be recorded at the start and end of each observation 
watch, every 30 minutes during a watch, and whenever there is a change 
in any of those variables.

(2) Visual Shore-Based Monitoring

    In addition to the vessel-based PSOs, Apache will utilize a shore-
based station to visually monitor for marine mammals. The shore-based 
station will follow all safety procedures, including bear safety. The 
location of the shore-based station will need to be sufficiently high 
to observe marine mammals; the PSOs would be equipped with pedestal 
mounted ``big eye'' (20x110) binoculars. The shore-based PSOs would 
scan the area prior to, during, and after the airgun operations, and 
would be in contact with the vessel-based PSOs via radio to communicate 
sightings of marine mammals approaching or within the project area.

(3) Aerial-Based Monitoring

    When survey operations occur near a river mouth, Apache will 
utilize the crew helicopter to conduct aerial surveys near river mouths 
prior to the commencement of airgun operations in order to identify 
locations where beluga whales congregate. The helicopter may also be 
used at other times. The types of helicopters currently planned for use 
by Apache include a Bell 407, Bell UH1B, and ASB3. Weather and 
scheduling permitting, aerial surveys will fly at an altitude of 305 m 
(1,000 ft). In the event of a marine mammal sighting, aircraft will 
attempt to maintain a radial distance of 457 m (1,500 ft) from the 
marine mammal(s). Aircraft will avoid approaching marine mammals from 
head-on, flying over or passing the shadow of the aircraft over the 
marine mammal(s). By following these operational requirements, sound 
levels received underwater are not expected to meet or exceed NMFS 
harassment thresholds (Richardson et al., 1995; Blackwell et al., 
2002).

 (4) Acoustic Monitoring

    To further enhance detection of cetaceans, Apache will deploy 
passive acoustic monitoring (PAM) devices during the seismic survey. 
Apache anticipates utilizing the same system that was deployed during 
the 2D test program in March 2011 in Cook Inlet that was effective in 
detecting vocalizing belugas and harbor porpoises. Apache expects to 
deploy two PAM devices that will send real-time acoustic data via 
digital UHF radio-broadcast systems to the PAM operators aboard the M/V 
Dreamcatcher. The PAM operators will use specialized real-time 
detection software and audio playback to detect marine mammal sounds. 
If the PAM operators detect marine mammals, Apache will initiate a 
temporary shut-down of the airgun arrays to avoid takes. Following a 
shut-down, the airguns may be restarted in accordance with the ramp-up 
procedure described earlier.

Reporting Measures

 (1) SSV Report
    A report on the preliminary results of the acoustic verification 
measurements, including at a minimum the measured 190 =, 180 =, and 160 
= dBrms re 1 [mu]Pa radii of the airgun arrays and pinger, 
will be submitted within 120 hr after collection and analysis of those 
measurements at the start of the field season. This report will specify 
the distances of the exclusion zones that were adopted for the seismic 
survey activities.
(2) Field Reports
    During the proposed survey program, the PSOs will prepare a report 
each day summarizing the recent results of the monitoring program. The 
field reports will summarize the species and numbers of marine mammals 
sighted. These reports will be provided to NMFS and to the survey 
operators on a weekly basis.
(3) Technical Report
    The results of Apache's 2012 monitoring program, including 
estimates of ``take'' by harassment (based on presence in the 160 dB 
harassment zone), will be presented in a ``90-day'' and a Final 
Technical report. The Technical Report will include:
    (a) Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
    (b) Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    (c) Species composition, occurrence, and distribution of marine 
mammal sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), group sizes, and ice cover;
    (d) Analyses of the effects of survey operations;
     Sighting rates of marine mammals during periods with and 
without seismic survey activities (and other variables that could 
affect detectability), such as:
     Initial sighting distances versus survey activity state;
     Closest point of approach versus survey activity state;
     Observed behaviors and types of movements versus survey 
activity state;
     Numbers of sightings/individuals seen versus survey 
activity state;
     Distribution around the source vessels versus survey 
activity state; and
     Estimates of take by Level B harassment based on presence 
in the 160 dB disturbance zone.
(4) Comprehensive Report
    Following the survey season, a comprehensive report describing the 
vessel-based, shore-based, aerial-based, and acoustic monitoring 
programs will be prepared. The comprehensive report will describe the 
methods, results, conclusions and limitations of each of the individual 
data sets in detail. The report will also integrate (to the extent 
possible) the studies into a broad based assessment of industry 
activities, and other activities that occur in Cook Inlet, and their 
impacts on marine mammals. The report will help to establish long-term 
data sets that can assist with the evaluation of changes in the Cook 
Inlet ecosystem. The report will attempt to provide a regional 
synthesis of available data on industry activity in this part of Alaska 
that may influence marine mammal density, distribution and behavior.
(5) Notification of Injured or Dead Marine Mammals
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA, 
such as an injury, serious injury or mortality (e.g., ship-strike, gear 
interaction, and/or entanglement), Apache will immediately cease the 
specified activities and immediately report the incident to the Chief 
of the Permits,

[[Page 27731]]

Conservation, and Education Division, Office of Protected Resources, 
NMFS, and the Alaska Regional Stranding Coordinators. The report must 
include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).

Activities will not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with Apache to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Apache may not resume their 
activities until notified by NMFS via letter, email, or telephone.
    In the event that Apache discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
Apache will immediately report the incident to the Chief of the Permits 
and Conservation Division, Office of Protected Resources, NMFS, and the 
NMFS Alaska Stranding Hotline and/or by email to the Alaska Regional 
Stranding Coordinators. The report must include the same information 
identified in the paragraph above. Activities may continue while NMFS 
reviews the circumstances of the incident. NMFS will work with Apache 
to determine whether modifications in the activities are appropriate.
    In the event that Apache discovers an injured or dead marine 
mammal, and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), Apache will report the incident to 
the Chief of the Permits, Conservation, and Education Division, Office 
of Protected Resources, NMFS, and the NMFS Alaska Stranding Hotline 
and/or by email to the Alaska Regional Stranding Coordinators, within 
24 hours of the discovery. Apache will provide photographs or video 
footage (if available) or other documentation of the stranded animal 
sighting to NMFS and the Marine Mammal Stranding Network.

Estimated Take of Marine Mammals

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [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 [Level B harassment]. Only take by Level B behavioral 
harassment is anticipated as a result of the proposed marine survey 
program. Anticipated impacts to marine mammals are associated with 
noise propagation from the sound sources (e.g., airguns and pingers) 
used in the seismic survey; no take is expected to result from the 
detonation of explosives onshore, as supported by the SSV study, or 
from vessel strikes.
    Apache requests authorization to take five marine mammal species by 
Level B harassment. These five marine mammal species are: Cook Inlet 
beluga whale (Delphinapterus leucas); killer whale (Orcinus orca); 
harbor porpoise (Phocoena phocoena); harbor seal (Phoca vitulina 
richardsi), and Steller sea lion (Eumetopias jubatus).
    The full suite of potential impacts to marine mammals was described 
in detail in the ``Potential Effects of the Specified Activity on 
Marine Mammals'' section found earlier in this document and in the 
notice of proposed IHA. The potential effects of sound from the 
proposed seismic survey might include one or more of the following: 
tolerance; masking of natural sounds; behavioral disturbance; non-
auditory physical effects; and, at least in theory, temporary or 
permanent hearing impairment (Richardson et al., 1995). The most common 
and likely impact will be from behavioral disturbance, including 
avoidance of the ensonified area or changes in speed, direction, and/or 
diving profile of the animal. Hearing impairment (TTS and PTS) are 
highly unlikely to occur based on the required mitigation and 
monitoring measures that would preclude marine mammals being exposed to 
noise levels high enough to cause hearing impairment.
    For impulse sounds, such as those produced by airgun(s) and pingers 
used in the seismic survey, NMFS uses a received level of 160 
dBrms re 1 [mu]Pa to indicate the onset of Level B 
harassment. However, not all animals react to sounds at this level, and 
many will not show strong reactions (and in some cases any reaction) 
until sounds are stronger. Southall et al. (2007) provide a severity 
scale for ranking observed behavioral responses of both free-ranging 
marine mammals and laboratory subjects to various types of 
anthropogenic sound (see Table 4 in Southall et al. (2007)). Tables 7, 
9, and 11 in Southall et al. (2007) outline the numbers of low-
frequency cetaceans, mid-frequency cetaceans, and pinnipeds in water, 
respectively, reported as having behavioral responses to multi-pulses 
in 10-dB received level increments. These tables illustrate that while 
some studies have found moderate responses at these levels, some show 
that more severe reactions did not occur until sounds were much higher 
than 160 dBrms re 1[mu]Pa.)
    To estimate take by Level B harassment, Apache provided 
calculations for the size of the 160-dB isopleths and then overlaid 
those isopleths with the density of marine mammals in the total area 
ensonified within those isopleths over the time of the surveys. Apache 
provided a full description of the methodology used to estimate takes 
by harassment in its IHA application (see ADDRESSES), which is also 
provided in the following sections. NMFS used Apache's takes estimates 
in its analyses.
    More specifically, to estimate takes by harassment, ranges to the 
160 dBrms re 1 [micro]Pa isopleths were estimated at three 
different water depths (5 m, 25 m, and 45 m) for nearshore surveys and 
at 80 m for channel surveys. The distances to these isopleths are 
provided in Table 1. The areas ensonified to the 160 dB isopleth for 
the nearshore survey are provided in Table 2. The area ensonifed to the 
160 dB isopleth for the channel survey is 389 km\2\.

[[Page 27732]]



        Table 2--Areas Ensonified to 160 dB for Nearshore Surveys
------------------------------------------------------------------------
                                                          Area ensonifed
  Nearshore survey depth classification     Depth range      to 160 dB
                                                (m)           (km\2\)
------------------------------------------------------------------------
Shallow.................................            5-21             346
Mid-Depth...............................           21-38             458
Deep....................................           38-54             455
------------------------------------------------------------------------

    The following subsections describe how the estimated densities of 
marine mammals that may occur in the area were derived. It is important 
to note that, based on the comment letter received from the Marine 
Mammal Commission that pointed out errors in the density estimates for 
belugas, harbor porpoises, harbor seals, and Steller sea lions, the 
densities found in Table 4 below have changed since the notice of the 
proposed IHA (76 FR 58473, September 21, 2011). These corrected 
densities were used to estimate the number of Level B harassment takes 
incidental to the proposed activity.
    Marine mammal densities near the planned activities in Cook Inlet 
were estimated from the annual aerial surveys conducted by NMFS between 
2000 and 2010 for Cook Inlet beluga whales (Rugh et al., 2000, 2001, 
2002, 2003, 2004, 2005, 2006, 2007; Shelden et al., 2008, 2009, 2010). 
These surveys are flown in June to collect abundance data for beluga 
whales, but sightings of other marine mammals are also reported, and 
these data were used for estimating the densities of the other species. 
Although these data are only collected in one month each year, and 
therefore do not account for seasonal variations in distribution or 
habitat use of each species, these surveys provide the best available 
relatively long-term data set for sighting information in the proposed 
action area. The general trend in marine mammal sightings is that 
beluga whales and harbor seals are seen most frequently in upper Cook 
Inlet, with higher concentrations of beluga whales near river mouths 
(particularly the Susitna River) and of harbor seals near haul out 
sites on Kalgin Island. The other marine mammals for which takes were 
estimated (killer whales, harbor porpoises, and Steller sea lions) are 
observed infrequently in upper Cook Inlet and more commonly in lower 
Cook Inlet. In addition, these densities are calculated based on a 
survey of a relatively large area, which is much larger than the survey 
site. Therefore, the use of these data to estimate density is 
considered to result in overestimates with respect to the probability 
of observing these animals in the action area. The maximum and average 
densities over the course of the total survey years (2000-2010) are 
provided in Table 3.
    As discussed below, beluga whales are observed in higher 
concentrations near river mouths, particularly the Susitna River, due 
to feeding. Therefore, to account for the higher concentrations near 
river mouths, the highest number of beluga whales observed for each 
year was used to provide a density for river mouths. To account for the 
lower concentrations away from river mouths, the average number of 
beluga whales observed for each year was used to provide a density away 
from river mouths. A maximum and average density are provided to 
account for the inherent level of uncertainty in using aerial surveys 
conducted for a few days once a year in order to estimate density for 
the entire year.

               Table 3--Summary of Marine Mammal Densities
------------------------------------------------------------------------
                                              Density  (number/km\2\)
                 Species                 -------------------------------
                                              Maximum         Average
------------------------------------------------------------------------
Beluga whale (average number observed)..         0.00021         0.00011
Beluga whale (maximum number observed--          0.00128         0.00051
 rivers)................................
Harbor seal (total number observed).....         0.00644         0.00317
Harbor porpoise (total number observed).         0.00037         0.00006
Killer whale (total number observed)....         0.00011         0.00001
Steller sea lion (total number observed)         0.00035         0.00011
------------------------------------------------------------------------

    Below, we provide estimates of the number of individuals 
potentially exposed to sound levels >=160 dBrms re 1 [mu]Pa 
during seismic survey operations. The estimates were calculated by 
multiplying the expected densities by the anticipated area ensonified 
by levels >=160 dBrms re 1 [mu]Pa by the number of expected 
days that will be subject to seismic survey activities in the action 
area. According to section 2 in Apache's IHA application, a survey crew 
will collect seismic data 10-12 hours per day over approximately 160 
days over the course of 8 to 9 months. Apache assumes that over the 
course of these 160 days, 100 days would be working in the offshore 
region and 60 days would be working in the shallow, intermediate, and 
deep nearshore region. Of those 60 days in the nearshore region, 20 
days would be spent working in each of the three depths. Because 
operations would occur over 12 hours per day, but acoustic footprints 
were calculated based on 24 hours of survey activity (i.e., the 
distance a vessel would travel in 24 hours was used to calculate the 
square km ensonified in a day, and then that total was multiplied by 
the number of days that the survey vessel would be operating), the 
total number of days for each region was divided by two (or half a day) 
for purposes of calculating takes. It is important to note that 
environmental conditions (such as ice, wind, and fog) will play a 
significant role in the actual number of operating days; therefore, 
these estimates, which are based on the best case scenario and optimal 
environmental conditions, likely overestimate the probability of 
encountering these marine mammal species in the action area because the 
actual number of operating are likely to be fewer.

[[Page 27733]]

    The number of estimated takes by Level B harassment was calculated 
using the following assumptions:
     The number of nearshore and shallow water survey days is 
10 (20 days/12 hours) and daily acoustic footprint is 356 km\2\.
     The number of nearshore and intermediate water depth 
survey days is 10 (20 days/12 hours) and daily acoustic footprint is 
468 km\2\.
     The number of nearshore and deep water depth survey days 
is 10 (20 days/12 hours) and daily acoustic footprint is 455 km\2\.
     The number of offshore survey days is 50 (100 days/12 
hours) and daily acoustic footprint is 389 km \2\.
    As noted above, Apache modeled the acoustic footprints of the 
airgun arrays in order to estimate the 160 dB isopleth. The modeling 
report is attached to the IHA application as Appendix A and summarized 
below. The nearshore locations were sub-divided into the following 
three depth intervals because of the sloping bottom contour along the 
sides of Cook Inlet: 5-21 m; 21-38 m; and 38-54 m. Due to the 
relatively constant depth in the Inlet's main channel, the channel 
scenario used a water depth of 80 m. The nearshore survey depth 
interval subdivisions are based on the zones that can be surveyed in 24 
hour periods based on the anticipated nominal survey length of 16.1 km, 
and survey line spacing of 503 m. Apache estimates that it can complete 
12-14 survey lines per day based on normal survey vessel speed 
(approximately 2-4 knots). The depth intervals each correspond with 14 
adjacent parallel lines based on the rate of depth increase with 
distance from shore. The different depth intervals were considered 
separately because the size of the airgun array sound footprint varies 
with water depth. The largest possible airgun array configuration of 
2400 cui was applied to model the noise footprints used in the take 
calculations, which means that the 160-dB isopleths are likely 
overestimates when applied to the small arrays that may be used during 
the actual survey.
    The nearshore modeling scenarios were examined by placing the 
source at three distances offshore corresponding to the following water 
depths: 5, 25, and 45 m. For each source position, the model predicted 
distances to the 160 dB re [micro]1 Pa (rms) threshold in multiple 
directions. These distances were subsequently interpolated to predict 
threshold distances for survey source positions at all depths between 5 
m and 54 m. The deep channel survey scenario, with a constant water 
depth of 80 m, was modeled to predict the distances in the endfire and 
broadside directions relative to the array where sound levels 
attenuated to 160 dB re [micro]1 Pa (rms).
    The 24-hour composite acoustic footprints were calculated from the 
footprints of the individual survey lines. Each survey line footprint 
was estimated using a rectangle that encompassed the 160 dB broadside 
(in shore and offshore directions) and endfire (along-shore) extents 
for all airgun pulses on that line. The union of 14 survey line 
footprints created the 24-hour composite acoustic footprint. The union 
of the single line footprint is smaller than their sum because of 
overlap.
    Table 4 shows the estimated maximum and average exposures to levels 
above 160dB by species for the first year of seismic surveys in Cook 
Inlet based on the assumptions outlined above. However, when the 
density and distribution data for certain species are considered more 
carefully, as well as the likely effect of the required mitigation 
measures, the take estimates may be further refined as illustrated by 
the requested and authorized number of takes below.
    The use of the NMFS aerial survey data has inherent weaknesses that 
need to be considered. For example, the estimated number of harbor seal 
takes by Level B harassment is higher than what is actually anticipated 
because there are no haul-out sites within the action area. Seals in 
some numbers are expected to be observed in the Susitna River delta, 
but not in the large numbers that are observed in lower Cook Inlet. The 
density estimates used to calculate take are skewed upward by the 
numbers observed in large haul outs during aerial surveys. Seals in the 
water usually travel in small groups or as single individuals; 
therefore, although Table 4 indicates an average of 102 and maximum of 
207 seals exposed to sounds likely to result in Level B harassment, it 
is highly unlikely that those number of seals will actually be taken 
during the proposed seismic survey. To account for the likely 
overestimate of takes by Level B harassment due to the location of the 
seismic survey and lack of haul-out sites in the vicinity, Apache 
requested and NMFS authorizes 50 takes instead.
    Similarly, NMFS expects the number of actual Steller sea lion takes 
by Level B harassment to be lower than the average of four and maximum 
of 11 indicated in Table 4. During the NMFS aerial surveys, no Steller 
sea lions were observed in upper Cook Inlet. Less than five Steller sea 
lions have been observed by the Port of Anchorage monitoring program, 
and those observed have been juvenile animals (likely male). Apache 
estimated that there could be 11 Steller sea lions takes by Level B 
harassment in the proposed action area during the one-year effective 
period of the IHA; nevertheless, to account for variability and 
anomalous years where higher than average numbers of Steller sea lions 
are reported in Cook Inlet, Apache requests and NMFS authorizes 20 
takes by Level B harassment.
    The average and maximum take estimates for harbor porpoise and 
killer whales shown in Table 4. Although the actual number of animals 
expected to be encountered during seismic survey activities is lower, 
Apache requests and NMFS authorizes 20 takes of harbor porpoises and 10 
takes of killer whales--both by Level B harassment only--to account for 
annual variability in abundance and distribution in Cook Inlet.
    The average and maximum estimated number of takes by Level B 
harassment for Cook Inlet beluga whales away from river mouths is two 
and five, respectively. Given that beluga are usually transiting from 
one feeding area to another in lower concentrations, these estimates 
appear to be reasonable in assessing the probability for potentially 
observing beluga whales in the action area. However, it is important to 
note that a combination of visual and acoustic monitoring will be used 
extensively throughout this project, particularly for detecting beluga 
whales approaching the area, and to trigger shutdowns and powerdowns of 
sound sources, which also has the potential to reduce the actual number 
of takes.
    The average and maximum estimated number of takes by Level B 
harassment for Cook Inlet beluga whales near river mouths is 16 and 41 
animals, respectively. The total number of days actually surveying near 
river mouths (60 days in the shallow, intermediate, and deep nearshore 
region) is much lower than the 160 days used to estimate takes in the 
different water depths, and again, the estimate does not take into 
account mitigation; therefore, this take estimate is likely to be an 
overestimate. As a result, due to the actual number of days and hours 
Apache is likely to be operating airguns near river mouths and taking 
into account the monitoring and mitigation measures applicable when 
operating seismic survey equipment near rivers, Apache expects the 
actual number of takes by Level B harassment estimated for Cook Inlet 
beluga whales to be much lower than the numbers provided in Table 4. To 
account for this, Apache requests and NMFS authorizes

[[Page 27734]]

30 takes of Cook Inlet beluga whale by Level B harassment.

                 Table 4--Estimated Takes by Level B Harassment per Species (Without Mitigation)
----------------------------------------------------------------------------------------------------------------
                                      Shallow        Mid-depth         Deep          Offshore          Total
             Species             -------------------------------------------------------------------------------
                                    Max     Avg     Max     Avg     Max     Avg     Max     Avg     Max     Avg
----------------------------------------------------------------------------------------------------------------
Beluga whales--away from river       0.5     0.3     0.7     0.3     0.7     0.3     2.8     1.5     4.7     2.4
 mouths.........................
Beluga whales--near river mouths     4.5     1.8     5.8     2.3     5.8     2.3    24.8     9.9      41    16.3
Harbor seals....................    22.9    11.3    29.5    14.5    29.3    14.4   125.3    61.7     207   101.9
Harbor porpoises................     1.3     0.2     1.7     0.3     1.7     0.3     7.2     1.2    11.9     2.0
Killer whales...................     0.4     0.1     0.5     0.1     0.5     0.1     2.2     0.3     3.6     0.5
Steller sea lions...............     1.2     0.4     1.6     0.5     1.6     0.5     6.8     2.2    11.3     3.7
----------------------------------------------------------------------------------------------------------------


        Table 5--Authorized Number of Takes by Level B Harassment
------------------------------------------------------------------------
                                    Number of
             Species                requested    Population   Percent of
                                      takes      abundance    population
------------------------------------------------------------------------
Beluga whales....................           30          284           10
Harbor seals.....................           50       29,175         0.17
Harbor porpoises.................           20       31,406         0.06
Killer whales....................           10        1,123         0.89
Steller sea lions................           20       41,197         0.12
------------------------------------------------------------------------

Negligible Impact and Small Numbers Analysis and Determination

    NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the takes occur.
    Given the required mitigation and related monitoring, no injuries 
or mortalities are anticipated to occur as a result of Apache's 
proposed seismic survey in Cook Inlet, and none are proposed to be 
authorized. Additionally, animals in the area are not expected to incur 
hearing impairment (i.e., TTS or PTS) or non-auditory physiological 
effects. The small number of takes that are anticipated are expected to 
be limited to short-term Level B behavioral harassment. Although it is 
possible that some marine mammals individuals may be exposed to sounds 
from seismic survey activities more than once, the duration of these 
multi-exposures is expected to be low since both the animals and the 
survey vessels will be moving constantly in and out of the survey area 
and the seismic airguns do not operate continuously all day, but for a 
few hours at a time totaling about 12 hours a day.
    Odontocete (including Cook Inlet beluga whales, killer whales, and 
harbor porpoises) reactions to seismic energy pulses are usually 
assumed to be limited to shorter distances from the airgun(s) than are 
those of mysticetes, in part because odontocete low-frequency hearing 
is assumed to be less sensitive than that of mysticetes. However, at 
least when in the Canadian Beaufort Sea in summer, belugas appear to be 
fairly responsive to seismic energy, with few being sighted within 6-12 
mi (10-20 km) of seismic vessels during aerial surveys (Miller et al. 
2005). Due to the more dispersed distribution of beluga whales when 
Apache plans to commence its seismic surveys and the concentration of 
animals in the upper Inlet during spring and summer in response to the 
presence of prey species such as eulachon and salmon, belugas will 
likely occur in small numbers in Cook Inlet during the survey period 
and few will likely be affected by the survey activity in a manner that 
would be considered behavioral harassment. For the same reason, it is 
unlikely that any individual animal would be exposed to higher received 
levels multiple times.
    Taking into account the mitigation measures that are planned, 
effects on cetaceans are generally expected to be restricted to 
avoidance of a limited area around the survey operation and short-term 
changes in behavior, falling within the MMPA definition of ``Level B 
harassment''. Animals are not expected to permanently abandon the area, 
and any behaviors that are interrupted during the survey are expected 
to resume once the activity ceases. In addition, the area where the 
survey will take place is not known to be an important location where 
beluga whale congregate for feeding, calving, or nursing. Additionally, 
one of the mitigation measures specifically requires shut down of the 
airguns if a calf, or an aggregation of 5 or more beluga whales, is 
detected anywhere within the area where marine mammals would be 
expected to be behaviorally harassed by the sound levels Furthermore, 
the estimated numbers of animals potentially exposed to sound levels 
sufficient to cause Level B harassment are low percentages of the 
population sizes, as illustrated above in Table 5. Therefore, the 
exposure of cetaceans to sounds produced by the proposed seismic survey 
in Cook Inlet is not anticipated to have an effect on annual rates of 
recruitment or survival.
    Some individual pinnipeds may be exposed to sound from the proposed 
marine surveys more than once during the time frame of the project, but 
there are no know pinniped rookeries or haulouts in the vicinity of the 
survey site. As discussed previously, the exposure of pinnipeds to 
sounds produced by the proposed seismic survey in Cook Inlet is not 
expected to result in more than short-term Level B harassment of a low 
percentage of the affected species, and is not anticipated to have an 
effect on annual rates of recruitment or survival.

[[Page 27735]]

    Mitigation and monitoring measures such as controlled vessel speed, 
dedicated marine mammal observers, non-pursuit, ramp-up, and shut downs 
or power downs when marine mammals are seen within defined ranges or 
belugas are seen in certain groupings (calf or aggregation of 5 or 
more) at even greater ranges will further reduce both the number and 
severity of behavioral impacts and minimize any potential for effects 
on hearing sensitivity. In all cases, the effects are expected to be 
relatively short-term and limited to Level B harassment that is not 
expected to affect annual rates of recruitment or survival for any 
marine mammals.
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see the ``Anticipated Effects on Habitat'' 
section). Although some temporary acoustic disturbance is possible to 
food sources of marine mammals, the impacts are anticipated to be short 
term and minor enough (and not focused either in primary feeding areas 
or areas where many belugas are feeding at the time of the activity) 
that they would only have temporary behavioral impacts, and no lasting 
energetic impacts. Based on the size of Cook Inlet where feeding by 
marine mammals occurs versus the localized area of the marine survey 
activities, any missed feeding opportunities in the direct project area 
would be minor based on the fact that other feeding areas exist 
elsewhere throughout Cook Inlet.
    The requested takes proposed to be authorized represent 10 percent 
of the Cook Inlet beluga whale population of approximately 284 animals 
(Hobbs et al., 2011), 0.89 percent of the combined Alaska resident 
stock and Gulf of Alaska, Aleutian Island and Bering Sea stock of 
killer whales (1,123 residents and 314 transients), and 0.06 percent of 
the Gulf of Alaska stock of approximately 31,046 harbor porpoises. The 
take requests presented for harbor seals represent 0.17 percent of the 
Gulf of Alaska stock of approximately 29,175 animals. Finally, the 
requested takes proposed for Steller sea lions represent 0.12 percent 
of the western DPS of approximately 41,197 animals. These percentage 
estimates represent small numbers relative to the affected population 
sizes, and they represent the percentage of each species or stock that 
could be taken by Level B behavioral harassment if each animal is taken 
only once. In addition, the mitigation and monitoring measures in the 
IHA are expected to reduce even further these numbers by requiring that 
sources shut down for aggregations of five or more whales and/or beluga 
calf-cow pairs before they enter the Level B harassment take zone.
    Based on the analysis contained in this notice of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the mitigation and 
monitoring measures, NMFS finds that Apache's seismic survey in Cook 
Inlet may result in the incidental take of small numbers of marine 
mammals, by Level B harassment only, and that the total taking from the 
survey will have a negligible impact on the affected species or stocks.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

    Section 101(a)(5)(D) requires NMFS to determine that the 
authorization will not have an unmitigable adverse effect on the 
availability of marine mammal species or stocks for subsistence use. 
NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 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 subsistence harvest of marine mammals transcends the 
nutritional and economic values attributed to the animal and is an 
integral part of the cultural identity of the region's Alaska Native 
communities. Inedible parts of the whale provide Native artisans with 
materials for cultural handicrafts, and the hunting itself perpetuates 
Native traditions by transmitting traditional skills and knowledge to 
younger generations (NOAA 2007). However, due to dramatic declines in 
the Cook Inlet beluga whale population, on May 21, 1999, legislation 
was passed to temporarily prohibit (until October 1, 2000) the taking 
of Cook Inlet belugas under the subsistence harvest exemption in 
section 101(b) of the MMPA without a cooperative agreement between NMFS 
and the affected Alaska Native Organizations (ANOs) (Pub. L. No. 106-
31, section 3022, 113 Stat. 57,100). That prohibition was extended 
indefinitely on December 21, 2000 (Public Law No. 106-553, section 
1(a)(2), 114 Stat. 2762). NMFS subsequently entered into six annual co-
management agreements (2000-2003, 2005-2006) with the Cook Inlet Marine 
Mammal Council, an ANO representing Cook Inlet beluga hunters, which 
allowed for the harvest of 1-2 belugas. On October 15, 2008, NMFS 
published a final rule that established long-term harvest limits on the 
Cook Inlet beluga whales that may be taken by Alaska Natives for 
subsistence purposes (73 FR 60976). That rule prohibits harvest for a 
5-year period (2008-2012), if the average abundance for the Cook Inlet 
beluga whales from the prior five years (2003-2007) is below 350 
whales. The next 5-year period that could allow for a harvest (2013-
2017), would require the previous five-year average (2008-2012) to be 
above 350 whales.
    There is a low level of subsistence hunting for harbor seals in 
Cook Inlet. Seal hunting occurs opportunistically among Alaska Natives 
who may be fishing or travelling in the upper Inlet near the mouths of 
the Susitna River, Beluga River, and Little Susitna River.
    Consistent with NMFS' implementing regulations, Apache met with the 
CIMMC--the marine mammal ANO that represents Cook Inlet tribes--on 
March 29, 2011, to discuss the proposed activities and discuss 
subsistence concerns. Apache also met with the Tyonek Native 
Corporation on November 9, 2010, and the Salamat of Native Corporation 
on November 22, 2010. Additional meetings were held with the Native 
Village of Tyonek, the Kenaitze Indian Tribe, the Knik Tribal Council, 
and the Ninilchik Traditional Council. According to Apache, during all 
these meetings, no concerns were stated regarding potential conflict 
with subsistence harvest of marine mammals. Apache has identified the 
following features that are intended to reduce impacts to marine mammal 
subsistence users:
     In-water seismic activities will follow mitigation 
procedures to minimize effects on the behavior of marine mammals and, 
therefore, opportunities for harvest by Alaska Native communities;
     Regional subsistence representatives may support recording 
marine mammal observations along with marine mammal biologists during 
the monitoring programs and will receive marine mammal observation 
reports.
    Apache concluded, and NMFS agrees, that the size of the affected 
area, mitigation measures, and input from the consultations with CIMMC 
and Alaska Natives should result in the proposed action having no 
effect on the availability of marine mammals for subsistence uses. 
Apache and NMFS

[[Page 27736]]

recognize the importance of ensuring that Alaska Native Organizations 
and federally recognized tribes are informed, engaged, and involved 
during the permitting process and will continue to work with the ANOs 
and tribes to discuss their operations and activities.
    On February 6, 2012, in response to requests for government to 
government consultations by the CIMMC and Native Village of Eklutna, 
NMFS met with representatives from these two groups and a 
representative from the Ninilchik. We engaged in discussions about the 
proposed IHA, the MMPA process for issuing an IHA, concerns regarding 
Cook Inlet beluga whales, and achieving greater coordination with NMFS 
on issues that impact tribal concerns. NMFS considered these 
communications before issuing its IHA.
    NMFS anticipates that any effects from Apache's seismic survey on 
marine mammals, especially harbor seals and endangered Cook Inlet 
beluga whales, which are or have been taken for subsistence uses, would 
be short-term, site-specific, and limited to inconsequential changes in 
behavior and mild stress responses. NMFS does not anticipate that the 
authorized taking of affected species or stocks will reduce the 
availability of the species to a level insufficient for a harvest to 
meet subsistence needs by: (1) Causing the marine mammals to abandon or 
avoid hunting areas; (2) directly displacing subsistence users; or (3) 
placing physical barriers between the marine mammals and the 
subsistence hunters; and that cannot be sufficiently mitigated by other 
measures to increase the availability of marine mammals to allow 
subsistence needs to be met. Therefore, NMFS has determined that the 
authorized taking will not have an unmitigable adverse impact on the 
availability of Cook Inlet marine mammal stocks for subsistence uses.

Endangered Species Act (ESA)

    There are two marine mammal species listed as endangered under the 
ESA with confirmed or possible occurrence in the proposed project area: 
the Cook Inlet beluga whale and western DPS of Steller sea lion. On 
September 2, 2011, NMFS' Permits and Conservation Division initiated 
consultation with NMFS' Protected Resources Division under section 7 of 
the ESA on the issuance of an IHA to Apache under section 101(a)(5)(D) 
of the MMPA for this activity. Consultation was concluded and a 
biological opinion issued prior to issuance of the IHA. That biological 
opinion determined the proposed action is not likely to jeopardize the 
continued existence of the Cook Inlet beluga whales or the western DPS 
of Steller sea lions, or to destroy or adversely modify Cook Inlet 
beluga whale critical habitat.

National Environmental Policy Act (NEPA)

    NMFS prepared an Environmental Assessment to determine whether this 
proposed activity will have a significant effect on the human 
environment. This analysis was completed prior to the issuance of the 
IHA with NMFS' issuance of a Finding of No Significant Impact (FONSI).

Authorization

    NMFS has issued an incidental harassment authorization for the take 
of marine mammals incidental to Apache's seismic survey in Cook Inlet, 
Alaska, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated.

    Dated: May 4, 2012.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-11296 Filed 5-10-12; 8:45 am]
BILLING CODE 3510-22-P