Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Geophysical and Geotechnical Survey in Cook Inlet, Alaska, 50989-51018 [2015-20605]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 162 (Friday, August 21, 2015)]
[Notices]
[Pages 50989-51018]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-20605]



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Vol. 80

Friday,

No. 162

August 21, 2015

Part III





Department of Commerce





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 National Oceanic and Atmospheric Administration





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 Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to Geophysical and Geotechnical Survey in 
Cook Inlet, Alaska; Notice

Federal Register / Vol. 80 , No. 162 / Friday, August 21, 2015 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE018


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Geophysical and Geotechnical Survey 
in Cook Inlet, Alaska

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: NMFS is issuing an Authorization in response to a request from 
ExxonMobil Alaska LNG LLC (EMALL) for an authorization to take marine 
mammals, by harassment, incidental to a geophysical and geotechnical 
survey in Cook Inlet, AK, for 84 days between August 14, 2015 and 
August 13, 2016.

DATES: Effective August 14, 2015, through August 13, 2016.

ADDRESSES: Electronic copies of the Incidental Harrassment 
Authorization (IHA; Authorization), application, and associated 
Environmental Assessment (EA) and Finding of No Significant Impact 
(FONSI) may be obtained by writing to Jolie Harrison, Division Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Silver 
Spring, MD 20910, telephoning the contact listed below (see FOR FURTHER 
INFORMATION CONTACT), or visiting the internet at: https://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: Sara Young, Office of Protected 
Resources, NMFS, (301) 427-8484.

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 allow, 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.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. 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.''
    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

    On February 4, 2015, NMFS received an application from EMALL for 
the taking of marine mammals incidental to a geotechnical and 
geophysical survey in Cook Inlet, Alaska. NMFS determined that the 
application was adequate and complete on June 8, 2015.
    EMALL proposes to conduct a geophysical and geotechnical survey in 
Cook Inlet to investigate the technical suitability of a pipeline study 
corridor across Cook Inlet and potential marine terminal locations near 
Nikiski. The proposed activity would occur for 12 weeks during the 2015 
open water season after August 14, 2015. The following specific aspects 
of the proposed activities are likely to result in the take of marine 
mammals: Use of a seismic airgun, sub-bottom profiler (chirp and 
boomer), and potentially a vibracore. Take, by Level B Harassment only, 
of individuals of four species of marine mammals is anticipated to 
result from the specified activities.

Description of the Specified Activity

Overview

    The planned geophysical surveys involve remote sensors including 
single beam echo sounder, multibeam echo sounder, sub-bottom profiler 
(chirp and boomer), 0.983 L (60 in\3\) airgun, side scan sonar, 
geophysical resistivity meters, and magnetometer to characterize the 
bottom surface and subsurface. The planned shallow geotechnical 
investigations include vibracoring, sediment grab sampling, and piezo-
cone penetration testing (PCPT) to directly evaluate seabed features 
and soil conditions. Geotechnical borings are planned at potential 
shoreline crossings and in the terminal boring subarea within the 
Marine Terminal survey area, and will be used to collect information on 
the mechanical properties of in-situ soils to support feasibility 
studies for construction crossing techniques and decisions on siting 
and design of pilings, dolphins, and other marine structures. 
Geophysical resistivity imaging will be conducted at the potential 
shoreline crossings. Shear wave velocity profiles (downhole geophysics) 
will be conducted within some of the boreholes. Further details of the 
planned operations are provided below.

Dates and Duration

    Geophysical and geotechnical (G&G) surveys that do not involve 
equipment that could acoustically harass listed marine mammals began in 
May 2015. These surveys include echo sounders and side scan sonar 
surveys operating at frequencies above the hearing range of local 
marine mammals and geotechnical borings, which are not expected to 
produce underwater noise exceeding ambient. The remaining surveys, 
including use of sub-bottom profilers and the small airgun, will begin 
soon after receipt of the IHA. These activities would be scheduled in 
such a manner as to minimize potential effects to marine mammals, 
subsistence activities, and other users of Cook Inlet waters. It is 
expected that approximately 12 weeks (84 work days) are required to 
complete the G&G Program. The work days would not all be consecutive 
due to weather, rest days, and any timing restrictions.

Specified Geographic Region

    The Cook Inlet 2015 G&G Program will include geophysical surveys, 
shallow geotechnical investigations, and geotechnical borings. Two 
separate areas will be investigated and are shown in Figure 1 of the 
application: The pipeline survey area and the Marine Terminal survey 
area (which includes an LNG carrier approach zone). The pipeline survey 
area runs from the Kenai Peninsula, across the Inlet, up to Beluga, 
also considered the Upper Inlet. The Terminal area will include an area 
west and south of Nikiski, the northern edge of what is considered the 
Lower

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Inlet. The G&G Program survey areas (also referred to as the action 
area or action areas) are larger than the proposed pipeline route and 
the Marine Terminal site to ensure detection of all potential hazards, 
or to identify areas free of hazards. This provides siting flexibility 
should the pipeline corridor or Marine Terminal sites need to be 
adjusted to avoid existing hazards.
     Pipeline Survey Area--The proposed pipeline survey area 
(Figure 1) crosses Cook Inlet from Boulder Point on the Kenai Peninsula 
across to Shorty Creek about halfway between the village of Tyonek and 
the Beluga River. This survey area is approximately 45 km (28 mi) in 
length along the corridor centerline and averages about 13 km (8 mi) 
wide. The total survey area is 541 km2 (209 mi2). The pipeline survey 
area includes a subarea where vibracores will be conducted in addition 
to the geophysical surveys and shallow geotechnical investigations.
     Marine Terminal Survey Area--The proposed Marine Terminal 
survey area (Figure 1), encompassing 371 km2 (143 mi2), is located near 
Nikiski where potential sites and vessel routes for the Marine Terminal 
are being investigated. The Marine Terminal survey area includes two 
subareas: A seismic survey subarea where the airgun will be operated in 
addition to the other geophysical equipment, and a terminal boring 
subarea where geotechnical boreholes will be drilled in addition to the 
geophysical survey and shallow geotechnical investigations. The seismic 
survey subarea encompasses 25 km2 (8.5 mi2) and the terminal boring 
subarea encompasses 12 km2 (4.6 mi2).

Detailed Description of Activities

    The Notice of Proposed IHA (80 FR 37465, June 30, 2015) contains a 
full detailed description of the geotechnical and geophysical survey, 
including the sources proposed to be used and vessel details. That 
information has not changed and is therefore not repeated here.

Comments and Responses

    A Notice of Proposed IHA was published in the Federal Register on 
June 30, 2015 (80 FR 37465) for public comment. During the 30-day 
public comment period, NMFS received four comment letters from the 
following: The Marine Mammal Commission (MMC); the Natural Resource 
Defense Counsel (NRDC); Friends of Animals (FOA); and one private 
citizen.
    All of the public comment letters received on the Notice of 
Proposed IHA (80 FR 37465, June 30, 2015) are available on the internet 
at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Following is a 
summary of the public comments and NMFS' responses.
    Comment 1: One private citizen requested that we deny issuance of 
the IHA because marine mammals would be killed as a result of the 
survey.
    Response: The survey is not expected to result in the death of any 
marine mammal species, and no such take is authorized. Extensive 
analysis of the proposed geotechnical and geophysical survey was 
conducted in accordance with the MMPA, Endangered Species Act (ESA), 
and National Environmental Policy Act (NEPA). Pursuant to those 
statutes, we analyzed the impacts of the survey activities to marine 
mammals (including those listed as threatened or endangered under the 
ESA), their habitat (including critical habitat designated under the 
ESA), and to the availability of marine mammals for taking for 
subsistence uses. The MMPA analysis revealed that the activities would 
have a negligible impact on affected marine mammal species or stocks 
and would not have an unmitigable adverse impact on the availability of 
marine mammals for taking for subsistence uses. The ESA analysis 
concluded that the activities likely would not jeopardize the continued 
existence of ESA-listed species or destroy or adversely modify 
designated critical habitat. The NEPA analysis concluded that there 
would not be a significant impact on the human environment.
    Comment 2: The MMC and the NRDC recommend that NMFS defer issuance 
of any Authorization to EMALL or other applicants until NMFS concludes 
that those activities would affect no more than a small number of Cook 
Inlet beluga whales with a negligible impact on the population.
    Response: In accordance with our implementing regulations at 50 CFR 
216.104(c), we use the best available scientific information to 
determine whether the taking by the specified activity within the 
specified geographic region will have a negligible impact on the 
species or stock and will not have an unmitigable adverse impact on the 
availability of such species or stock for subsistence uses. Based on 
the best scientific information available, NMFS determined that the 
impacts of the geotechnical and geophysical survey program, which are 
primarily acoustic in nature, would meet these standards. Moreover, 
EMALL proposed and NMFS has required in the IHA a rigorous mitigation 
plan to reduce impacts to Cook Inlet beluga whales and other marine 
mammals to the lowest level practicable, including measures to shutdown 
active acoustic sources if any beluga whale is observed approaching or 
within the Level B harassment zone and restricting activities within a 
10 mi (16 km) radius of the Susitna Delta from April 15 through October 
15, which is an important area for beluga feeding and calving in the 
spring and summer months. This shutdown measure is more restrictive 
than the standard shutdown measures typically applied, and combined 
with the Susitna Delta exclusion (minimizing adverse effects to 
foraging), is expected to reduce both the scope and severity of 
potential harassment takes, minimizing impacts from the harassment that 
would adversely affect reproductive rates or survivorship.
    Our analysis indicates that issuance of this IHA will not 
contribute to or worsen the observed decline of the Cook Inlet beluga 
whale population. Additionally, the ESA Biological Opinion determined 
that the issuance of an IHA is not likely to jeopardize the continued 
existence of the Cook Inlet beluga whales or adversely modify Cook 
Inlet beluga whale critical habitat. The Biological Opinion also 
outlined Terms and Conditions and Reasonable and Prudent Measures to 
reduce impacts, which have been incorporated into the IHA. Therefore, 
based on the analysis of potential effects, the parameters of the 
survey, and the rigorous mitigation and monitoring program, NMFS 
determined that the activity would have a negligible impact on the 
population.
    Moreover, the survey would take by Level B harrassment only small 
numbers of marine mammals relative to their population sizes. As 
described in the proposed IHA Federal Register notice, NMFS used a 
method that incorporates density of marine mammals overlaid with the 
anticipated ensonified area and the number of days of the operation to 
calculate an estimated number of takes for belugas. The number of 
belugas likely to be taken represents 7.04% of the population, which 
NMFS considers small. In addition to this quantitative evaluation, NMFS 
has also considered qualitative factors that further support the 
``small numbers'' determination, including: (1) The seasonal 
distribution and habitat use patterns of Cook Inlet beluga whales, 
which suggest that for much of the time only a small portion of the 
population would be accessible to impacts from EMALL's activity, as 
most animals are concentrated in upper Cook Inlet; and (2) the 
mitigation requirements, which provide spatio-temporal limitations that 
avoid impacts to large numbers of animals feeding and

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calving in the Susitna Delta and limit exposures to sound levels 
associated with Level B harassment. Based on all of this information, 
NMFS determined that the number of beluga whales likely to be taken is 
small. See response to Comment 3 and our small numbers analysis later 
in this document for more information about the small numbers 
determination for beluga whales and the other marine mammal species.
    Comment 3: The MMC recommends that before issuing any 
Authorizations, NMFS develop clear criteria for determining what 
constitutes small numbers and negligible impact for the purpose of 
authorizing incidental take of marine mammals.
    Response: NMFS consistently assesses clearly articulated factors in 
making both the small numbers and negligible impact findings in our 
actions, and those findings are supported for this action as described 
in this notice. However, we are currently assessing our criteria for 
determining what constitutes ``small numbers'' and are working towards 
the development of an improved, and more quantitative, analytical 
framework for determining whether an activity will have a ``negligible 
impact'' for the purpose of authorizing takes of marine mammals. We 
fully intend to engage the MMC in these processes at the appropriate 
time.
    Comment 4: The MMC and NRDC recommend that NMFS finalize and 
implement the beluga whale recovery plan, issue its programmatic EIS, 
and establish annual limits on the types of takes authorized for sound-
producing activities in Cook Inlet before issuing additional 
Authorizations.
    Response: NMFS recognizes the release of the draft recovery plan 
and, as an agency, will address and implement appropriate 
recommendations made in the recovery plan when the draft becomes a 
Final Recovery Plan, after NMFS has been able to incorporate public 
comment on the draft version.
    Further, NMFS is making progress toward the development of the Cook 
Inlet EIS to analyze the environmental impacts of issuing Incidental 
Take Authorizations (ITAs) pursuant to the Marine Mammal Protection Act 
(MMPA) for the taking of marine mammals incidental to anthropogenic 
activities in the waters of Cook Inlet, AK, but in the meanwhile is 
also requesting that all Cook Inlet applicants requesting 
authorizations for the 2016 open water season send in their 
applications by October 1, 2015. This will enable NMFS to conduct a 
Programmatic EA for these activities and better analyze the cumulative 
effects from all of the authorizations proposed for each open water 
season until the EIS is complete.
    Comment 5: The MMC, NRDC, and FOA commented on an error in beluga 
density information used to estimate the number of beluga exposures in 
the proposed authorization. The MMC and NRDC recommend that NMFS 
provide public notice of the revised number of beluga whale takes that 
NMFS proposes to authorize along with a revised analysis.
    Response: NMFS acknowledges the error in beluga density information 
and has revised the calculations used for take estimation presented in 
the Federal Register notice for the proposed IHA. The correction 
results in a revised exposure estimate of 30 belugas. However, 
following discussions with the applicant, the MMC, and the Alaska 
Regional Office, NMFS has determined that exposures due to the chirp 
will not be included in the Authorization, as the chirp and the boomer 
will be operating concurrently and the 160-dB isopleth of the boomer is 
larger than that of the chirp. Therefore, NMFS is authorizing take by 
Level B harrassment of only 24 belugas. This new exposure estimate 
represents 7.06% of the population, whereas the original estimate of 14 
represented 4.12% of the population. This difference does not 
substantively affect NMFS' analysis of effects, nor does it change the 
small numbers or negligible impact determinations, and therefore it 
does not merit a second public comment period.
    Comment 6: The MMC and NRDC recommend that until behavior 
thresholds are updated, that NMFS require applicants to use the 120-dB 
rather than 160-dB threshold for sub-bottom profilers.
    Response: The 120-dB threshold is typically associated with 
continuous sources. Continuous sounds are those whose sound pressure 
level remains above that of the ambient sound, with negligibly small 
fluctuations in level (NIOSH, 1998; ANSI, 2005). Intermittent sounds 
are defined as sounds with interrupted levels of low or no sound 
(NIOSH, 1998). Sub-bottom profiler signals are intermittent sounds. 
Intermittent sounds can further be defined as either impulsive or non-
impulsive. Impulsive sounds have been defined as sounds which are 
typically transient, brief (<1 sec), broadband, and consist of a high 
peak pressure with rapid rise time and rapid decay (ANSI, 1986; NIOSH, 
1998). Non-impulsive sounds typically have more gradual rise times and 
longer decays (ANSI, 1995; NIOSH, 1998). Sub-bottom profiler signals 
have durations that are typically very brief (<1 sec), with temporal 
characteristics that more closely resemble those of impulsive sounds 
than non-impulsive sounds. With regard to behavioral thresholds, we 
therefore consider the temporal and spectral characteristics of sub-
bottom profiler signals to more closely resemble those of an impulse 
sound rather than a continuous sound. The 160-dB threshold is typically 
associated with impulsive sources.
    The MMC suggests that, for certain sources considered here, the 
interval between pulses is so small it should be considered continuous. 
However, a sub-bottom profiler chirp's ``rapid staccato'' of pulse 
trains is emitted in a similar fashion as odontocete echolocation click 
trains. Research indicates that marine mammals, in general, have 
extremely fine auditory temporal resolution and can detect each signal 
separately (e.g., Au et al., 1988; Dolphin et al., 1995; Supin and 
Popov, 1995; Mooney et al., 2009), especially for species with 
echolocation capabilities. Therefore, it is highly unlikely that marine 
mammals would perceive sub-bottom profiler signals as being continuous.
    In conclusion, sub-bottom profiler signals are intermittent rather 
than continuous signals, and the fine temporal resolution of the marine 
mammal auditory system allows them to perceive these sounds as such. 
Further, the physical characteristics of these signals indicate a 
greater similarity to the way that intermittent, impulsive sounds are 
received. Therefore, the 160-dB threshold (typically associated with 
impulsive sources) is more appropriate than the 120-dB threshold 
(typically associated with continuous sources) for estimating takes by 
behavioral harassment incidental to use of such sources.
    We agree with the MMC'c recommendation to revise existing acoustic 
criteria and thresholds as necessary to specify threshold levels that 
would be more appropriate for a wider range of sound sources, and are 
currently in the process of producing such revisions. In particular, 
NMFS recognizes the importance of context (e.g., behavioral state of 
the animals, distance) in behavioral responses. The current behavioral 
categorization (i.e., impulse vs. continuous) does not account for 
context and is not appropriate for all sound sources. Thus, updated 
NOAA Acoustic Guidance (www.nmfs.noaa.gov/pr/acoustics/guidelines.htm), 
once completed, will more appropriately categorize behavioral 
harassment criteria by activity type. NOAA recognizes, as new science 
becomes available, that our current categorizations (i.e., impulse vs.

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continuous) may not fully encompass the complexity associated with 
behavioral responses (i.e., context, etc.) and are working toward 
addressing these issues in future acoustic guidance. However, in the 
meanwhile, while our current behavioral acoustic thresholds may not 
fully account for some of the differences observed across taxa and 
contexts, they still serve as somewhat conservative generalized 
indicators of received levels at which we anticipate behavioral 
harassment, and are not undermined by newer information.
    Comment 7: The MMC and NRDC recommend that prior to issuance of the 
Final Authorization, NMFS include taking by Level B harassment of 
humpback whales, gray whales, minke whales, Dall's porpoise, and 
Steller sea lion.
    Response: The issuance of an Authorization to an applicant is a 
request-based process. On the one hand, if NMFS believes that marine 
mammals will be taken that are not identified by the applicant, we will 
work with the applicant to modify the request to ensure inclusion of 
affected species. On the other hand, applicants sometimes request take 
of a small number of species that NMFS believes are unlikely to be 
encountered but NMFS will authorize take of those species as long as 
the necessary findings can be made. NMFS acknowledges that it has 
authorized the take of the species identified by commenters that occur 
infrequently in Cook Inlet in other Authorizations. However, in those 
instances, the applicant requested take of those species and NMFS 
analyzed the requests submitted. EMALL believes, and NMFS concurs, that 
with the required monitoring, small zones of influence, and short 
operating period (as compared to previous activities authorized in Cook 
Inlet), the activities are unlikely to result in the take any of the 
species identified by the commenters. Moreover, if a species for which 
take is not authorized is encountered, the Authorization text states 
that the applicant must shut down active sound sources.
    Comment 8: The MMC recommends that NMFS require EMALL to monitor 
for marine mammals for 30 minutes after authorized activities have 
ceased.
    Response: NMFS agrees with the MMC and has added a post-activity 
monitoring period of 30 minutes as a requirement for this activity. A 
30-minute monitoring period after the cessation of authorized sound 
source operations can provide useful observations to compare the 
behavior and abundance of animals during different scenarios of various 
noise levels. This change has been noted in the Authorization text.
    Comment 9: The MMC and NRDC recommend that NMFS allow sufficient 
time between the close of the comment period and issuance of an 
Authorization for NMFS to analyze, consider, and respond fully to 
comments received and incorporate changes as appropriate.
    Response: NMFS acknowledges that the time between the close of 
public comment and the target date for issuing the Authorization is 
short. However, NMFS fully considered and responded to all comments 
before issuing the Authorization, and incorporated changes as 
appropriate (i.e., see response to Comment 8).
    Comment 10: The NRDC and FOA comment that NEPA mandates that NMFS 
may not authorize activities while a programmatic EIS is underway. The 
NRDC references 40 CFR 1506.1.
    Response: NMFS acknowledges that it is preparing an EIS for 
incidental take authorizations in Cook Inlet, AK (79 FR 61616; October 
14, 2014). However, NMFS is undertaking this environmental analysis 
voluntarily as a decision support tool for processing MMPA ITA requests 
in Cook Inlet. The programmatic EIS is meant to address anticipated 
future levels of activity in Cook Inlet, which may include increases in 
activity, not a specific proposed program or project. NMFS will 
continue to prepare EAs or EISs, as appropriate, for specific 
individual applications for Incidental Take Authorizations (ITA) at 
this time. Consistent with its obligations under NEPA, NMFS prepared an 
EA (including an analysis of cumulative effects) prior to issuing the 
Authorization to EMALL and determined that issuance of the 
Authorization would not significantly impact the quality of the human 
environment.
    Comment 11: The NRDC commented that NMFS should not issue an 
Authorization until it has completed its revision of acoustic 
thresholds for take by Level B harrassment.
    Response: NMFS notes that NRDC's comment that NMFS uses an outdated 
and incorrect threshold for behavioral takes does not include any 
specific recommendations. NMFS uses 160 dB (rms) as the exposure level 
for estimating take by Level B harassment for most species in most 
cases. This threshold was established for underwater impulse sound 
sources 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). There is more recent 
information bearing on behavioral reactions to seismic airguns, but 
while those data illustrate how complex and context-dependent the 
relationship is between the two, they do not clearly suggest that there 
is a more appropriate level than 160dB to serve as general behavioral 
harassment threshold for multiple taxa. See 75 FR 49710, 49716 (August 
13, 2010) (IHA for Shell seismic survey in Alaska). Further, it is not 
a matter of merely replacing the existing threshold with a new one. 
NOAA is working to develop more sophisticated draft guidance for 
determining impacts from acoustic sources, including information for 
determining Level B harassment thresholds. Due to the complexity of the 
task, any guidance will require a rigorous review that includes 
internal agency review, public notice and comment, and additional 
external peer review before any final product is published. In the 
meantime, and taking into consideration the facts and available 
science, NMFS determined it is reasonable to use the 160 dB threshold 
for estimating takes of marine mammals in Cook Inlet by Level B 
harassment. However, we discuss the science on this issue qualitatively 
in our analysis of potential effects to marine mammals.
    Comment 12: The NRDC comments that NMFS should require the use of 
alternative technologies, including quieting technologies, as well as 
adopting additional time-area closures.
    Response: NMFS responds to this comment as part of the response to 
Comment 14 below.
    Comment 13: The NRDC comments that the suggestion that Cook Inlet 
belugas are habituated to certain levels of anthropogenic activity is 
outdated, given a study by Kendall et al. (2014) on impacts to belugas 
from construction noise.
    Response: NMFS acknowledges that there are scientific records of 
belugas responding to anthropogenic noise, as evidenced in Kendall et 
al. (2014). 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 et al., 1995). 
Reactions to vessels depends on whale activities and experience, 
habitat, boat type, and boat behavior (Richardson et al., 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.,

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1999; Scheifele et al., 2005); and changes in dive, surfacing, and 
respiration patterns.
    A study by Lessage et al. (1999) of belugas in the St. Lawrence 
River states with respect to modification of vocal behavior that 
``Owing to the gregarious nature of belugas, this would not pose a 
serious problem for intraherd communication, given the relatively short 
distances between herd members; a source of noise would have to be very 
close to them to potentially limit any communication within a herd. 
However, communication is probably not limited to herd members, since 
inter-herd communication may be important during the breeding season, 
when locating food sources, when navigating in ice, or when reacting to 
large-scale disturbance. On these larger scales, high noise levels 
could impair communication.'' NMFS acknowledges the potential for 
masking from the sound sources proposed by EMALL and discusses the 
potential effects of this. The concerns raised by NRDC in the paper by 
Bejder et al. (2009), that animals that do not display overt behavioral 
reactions could be incurring harm, is an important component of 
understanding the effects of tolerance on mammals in areas of 
increasing anthropogenic activity but no mechanism to estimate the 
physiological effects from tolerance are currently viable for this 
analysis. As noted above, though, even though shutdown measures are in 
place that will minimize behavioral harassment of belugas, NMFS does 
not reduce the amount of take expected/authorized due to possible 
habitation of belugas in Cook Inlet to anthropogenic noise, and the 
negligible impact determination below does not rely on an assumption of 
habitation to make the necessary findings.
    Comment 14: The NRDC comments that NMFS is failing to meet the 
requirement of setting forth ``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'' and urges 
NMFS to adopt meaningful mitigation and monitoring measures including 
requiring applicants to contribute to a comprehensive monitoring plan 
to better understand distribution as well as individual and cumulative 
effects of human activities on Cook Inlet belugas, which was 
incorporated by reference to NRDC's public comment on the Proposed Rule 
for Apache Alaska Corporation. In the Apache comment letter, the NRDC 
provides a list of approximately eight measures that NMFS ``failed to 
consider or adequately consider.''
    Response: NMFS provided a detailed discussion of proposed 
mitigation measures and the MMPA's ``least practicable impact'' 
standard in the notice of the proposed IHA (80 FR 37465, June 30, 
2015), which are repeated in the ``Mitigation'' section of this notice. 
The measures that NRDC alleges NMFS failed to consider or adequately 
consider are identified and discussed below:
    (1) Field testing and use of alternative technologies, such as 
vibroseis and gravity gradiometry, to reduce or eliminate the need for 
airguns and delaying seismic acquisition in higher density areas until 
the alternative technology of marine vibroseis becomes available: EMALL 
requested takes of marine mammals incidental to the geotechnical and 
geophysical survey operations described in the IHA application, which 
identified use of only a 60 in\3\ airgun array with a distance to the 
160-dB isopleth of 300m. It would be inappropriate for NMFS to 
fundamentally change the specified activity for which EMALL submitted 
an IHA application by requiring that they acquire data using an 
entirely different system of sound sources, especially if the alternate 
technology cannot meet the objectives of the proposed activity.
    EMALL knows of no current technology scaled for industrial use that 
is reliable enough to meet the environmental challenges of operating in 
Cook Inlet. An airgun is only one of several sources proposed by EMALL 
and alternative quieting technologies for the boomer, chirp, and 
vibracore are undeveloped at this time.
    (2) Required use of the lowest practicable source level in 
conducting airgun activity: EMALL is requesting to use a 60 in\3\ 
airgun, a very small source, for a duration of 7 days. This size of 
airgun, and the length and area of the survey, is necessary to meet 
EMALL's program objectives and minimize geotechnical, geohazard, and 
constructability risks.
    (3) Seasonal exclusions around river mouths, including early spring 
(pre-April 14) exclusions around the Beluga River and Susitna Delta, 
and avoidance of other areas that have a higher probability of beluga 
occurrence: NMFS has required a 10 mile (16 km) exclusion zone around 
the Susitna Delta (which includes the Beluga River) in this IHA. Survey 
operations involving the use of airgun, boomer, chirp, and vibracore 
will be prohibited in this area between April 15 and October 15. In 
both the MMPA and ESA analysis, NMFS determined that this date range is 
sufficient to protect Cook Inlet beluga whales and the critical habitat 
in the Susitna Delta. While data indicate that belugas may use this 
part of the inlet year round, peak use occurs from early May to late 
September. NMFS added a 2-week buffer on both ends of this peak usage 
period to add extra protection to feeding and calving belugas.
    (4) Limitation of the mitigation airgun to the longest shot 
interval necessary to carry out its intended purpose: EMALL is not 
proposing to use a mitigation airgun, therefore this measure does not 
apply.
    (5) Immediate suspension of airgun activity, pending investigation, 
if any beluga strandings occur within or within an appropriate distance 
of the survey area: The IHA requires EMALL to immediately cease 
activities and report unauthorized takes of marine mammals, such as 
live stranding, injury, serious injury, or mortality. NMFS will review 
the circumstances of EMALL's unauthorized take and determine if 
additional mitigation measures are needed before activities can resume 
to minimize the likelihood of further unauthorized take and to ensure 
MMPA compliance. EMALL may not resume activities until notified by 
NMFS. Separately, the IHA includes measures if injured or dead marine 
mammals are sighted and the cause cannot be easily determined. In those 
cases, NMFS will review the circumstances of the stranding event while 
EMALL continues with operations.
    (6) Establishment of a larger exclusion zone for beluga whales that 
is not predicated on the detection of whale aggregations or cow-calf 
pairs: Both the proposed IHA and the issued IHA contain a requirement 
for EMALL to delay the start of active acoustic source use or shutdown 
the active acoustic sources if a beluga whale is visually sighted 
approaching or within the 160-dB disturbance zone until the animal(s) 
are no longer present within the 160-dB zone. The measure applies to 
the sighting of any beluga whale, not just sighting of groups or cow-
calf pairs.
    Comment 15: FOA comments on several issues related to cumulative 
impacts analysis including: (1) NMFS contradicts the Draft Recovery 
Plan by issuing Authorizations, given that two concerns of note in the 
Plan include noise and cumulative/synergistic effects (2) each phase of 
the Alaska LNG project will add to increasing cumulative effects to 
Cook Inlet belugas (3) over the past three years, NMFS has authorized 
at least 288 takes by Level B harassment of Cook Inlet beluga whales 
and that takes for AK LNG must be addressed in the

[[Page 50995]]

context of cumulative impacts from other authorized takes.
    Response: Neither the MMPA nor NMFS' implementing regulations 
specify how to consider other activities and their impacts on the same 
populations when conducting a negligible impact analysis. 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).
    Although caution is warranted for noise-producing activities, 
especially in light of all of the other activities in Cook Inlet, NMFS 
does not agree that issuance of any Authorizations for take of Cook 
Inlet beluga whales is contradictory to recommendations in the Draft 
Recovery Plan for this species. NMFS is taking a cautious approach, 
both in the context of this particular project and Cook Inlet more 
broadly, to ensure that all impacts on beluga whales are adequately 
analyzed and minimized. For example, the shutdown of active sound 
sources at the 160-dB disturbance zone for beluga whales in Cook Inlet 
is a precautionary measure not used in other areas to ensure the 
minimization of behavioral harassment of belugas. Additionally, a 
precautionary approach was taken in estimating the number of exposures 
from the proposed EMALL survey, which is likely an overestimate of 
individuals taken for reason explained below in the `Take Estimation'' 
section related to number of individuals taken versus instances of 
exposure.
    More broadly, NMFS has announced our intent to prepare an EIS to 
better analyze cumulative impacts from potential increasing 
anthropogenic activities to Cook Inlet beluga whales. In addition, 
cumulative effects were addressed in the EA and Biological Opinion 
prepared for this action. The cumulative effects section of the EA has 
been expanded from the draft EA to discuss potential effects in greater 
detail. These documents, as well as the Alaska Marine Stock Assessments 
and the most recent abundance estimate for Cook Inlet beluga whales 
(Shelden et al, 2015), 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.
    NMFS will continue to analyze monitoring reports from authorized 
activities, applicable new science, and the increase of Cook Inlet 
activities in the context of the Cook Inlet Beluga Whale Recovery Plan, 
and will also continue to carefully evaluate proposed activities and 
recommend mitigation measures to ensure that the issuance of MMPA 
authorizations does not negatively impact the recovery of Cook Inlet 
belugas.
    Comment 16: FOA comments that the Environmental Assessment (EA) was 
difficult to find and recommends that NMFS re-open the public comment 
period for the EA as well as the Draft Recovery Plan for Cook Inlet 
belugas.
    Response: NMFS posted a draft of the EA on its Web site for public 
review: https://www.nmfs.noaa.gov/pr/permits/incidental/energy_other.htm. On July 6th, the MMC notified NMFS that the documents 
were placed under ``Other'' and not ``Natural Gas'' on the Web site. 
Once notified, NMFS corrected the error. During and after that time 
NMFS received no other communication from any persons or organizations 
requesting to be directed to those documents or asking for 
clarification as to their location. Therefore, NMFS does not believe 
the EA should be reopened for public comment. The Draft Recovery Plan 
for Cook Inlet beluga whales is a separate action and the reopening of 
its comment period is not relevant to this Authorization.
    Comment 17: FOA comments that the Marine Terminal area lies within 
beluga Critical Habitat. FOA also comments that effects on habitat 
could include disturbance to prey from noise, and disturbances to the 
environment from the platform's legs and project discharges from 
sampling activities.
    Response: The Federal Register notice of the proposed Authorization 
analyzed potential effects to prey species and marine mammal habitat. 
The possibility of adverse modification to Critical Habitat through 
reduction in prey species is addressed in the Biological Opinion, which 
resulted in a finding of no adverse modification to critical habitat.
    Comment 20: FOA comments that issuance of an IHA to EMALL would 
violate the ESA because granting the IHA would ``appreciably reduce the 
likelihood of survival and recovery of species in the wild.''
    Response: NMFS disagrees with FOA's comment. NMFS Office of 
Protected Resources (Permits and Conservation Division) initiated and 
engaged in formal consultation with NMFS Alaska Regional Office 
(Protected Resources Division) under section 7 of the ESA on the 
issuance of the IHA to EMALL. NMFS's Biological Opinion concluded that 
the issuance of the IHA is not likely to jeopardize the continued 
existence of listed species (e.g., would not appreciably reduce the 
ability of any listed species under NMFS' jurisdiction to survive and 
recover in the wild) or result in the destruction or adverse 
modification of critical habitat.
    Comment 21: FOA comments that NMFS must include a discussion of 
ethics and the rights of wildlife to manage wildlife-human interactions 
and suggests that this approach is consistent with NEPA and the ability 
to provide a ``full and fair discussion'' of the issues and inform 
decision makes and the public of the reasonable alternatives that would 
avoid or minimize adverse impacts or enhance the quality of the human 
environment. 40 CFR 1502.1.
    Response: Consistent with the requirements of NEPA and CEQ's 
implementing regulations, NMFS prepared an Environmental Assessment 
prior to issuing an IHA to EMALL that includes a comprehensive 
assessment of the effects of this action and alternative actions on the 
human environment, including the impacts of the action and alternative 
actions on marine mammal populations. While NMFS shares FAO's concerns 
regarding the ethical treatment of animals, it is not possible to 
directly address ethical treatment in the context of incidental and 
unintended effects (i.e., those authorized by this action), as any pain 
resulting from these impacts is far removed from any operator decisions 
and is neither observable, measurable or controllable. Instead, IHAs 
aim to minimize actual adverse effects to marine mammal individuals and 
populations.

Description of Marine Mammals in the Area of the Specified Activity

    Marine mammals that regularly inhabit upper Cook Inlet and Nikiski 
activity areas are the beluga whale (Delphinapterus leucas), harbor 
porpoise (Phocoena phocoena), and harbor seal (Phoca vitulina) (Table 
6). However, these species are found there in relatively low numbers, 
and generally only during the summer fish runs (Nemeth et al. 2007, 
Boveng et al. 2012). Killer whales (Orcinus orca) are occasionally 
observed in upper Cook Inlet where they have been observed attempting 
to prey on beluga whales (Shelden et al. 2003). Based on a number of 
factors, Shelden et al. (2003) concluded that the killer whales found 
in upper Cook Inlet to date are the transient type, while resident 
types

[[Page 50996]]

occasionally enter lower Cook Inlet. Marine mammals occasionally found 
in lower Cook Inlet include humpback whales (Megaptera novaeangliae), 
gray whales (Eschrichtius robustus), minke whales (Balaenoptera 
acutorostrata), Dall's porpoise (Phocoena dalli), and Steller sea lion 
(Eumetopias jubatus). Background information of species evaluated in 
this Authorization is detailed in Table 1 below.

                          Table 1--Marine Mammals Inhabiting the Cook Inlet Action Area
----------------------------------------------------------------------------------------------------------------
                                                                            Stock abundance        Relative
                                                       ESA/MMPA  status     (CV, Nmin, most   occurrence in Cook
            Species                     Stock        \1\;  strategic  (Y/  recent  abundance   Inlet; season of
                                                              N)              survey) \2\         occurrence
----------------------------------------------------------------------------------------------------------------
Killer whale...................  Alaska Resident...  -;N                  2,347 (N/A; 2,084;  Occasionally
                                 Alaska Transient..  -:N                   2009).              sighted in Lower
                                                                          345 (N/A; 303;       Cook Inlet.
                                                                           2003).
Beluga whale...................  Cook Inlet........  E/D;Y                312 (0.10; 280;     Use upper Inlet in
                                                                           2012).              summer and lower
                                                                                               in winter:
                                                                                               annual.
Harbor porpoise................  Gulf of Alaska....  -;Y                  31,046 (0.214;      Widespread in the
                                                                           25,987; 1998).      Inlet: annual
                                                                                               (less in winter).
Harbor seal....................  Cook Inlet/         -;N                  22,900 (0.053;      Frequently found
                                  Shelikof.                                21,896; 2006).      in upper and
                                                                                               lower inlet;
                                                                                               annual (more in
                                                                                               northern Inlet in
                                                                                               summer).
----------------------------------------------------------------------------------------------------------------

Beluga Whale (Delphinapterus leucas)

    The Cook Inlet beluga whale Distinct Population Segment (DPS) is a 
small geographically isolated population that is separated from other 
beluga populations by the Alaska Peninsula. The population is 
genetically (mtDNA) distinct from other Alaska populations, suggesting 
that the Peninsula is an effective barrier to genetic exchange 
(O'Corry-Crowe et al. 1997) and that these whales may have been 
separated from other stocks at least since the last ice age. Laidre et 
al. (2000) examined data from over 20 marine mammal surveys conducted 
in the northern Gulf of Alaska and found that sightings of belugas 
outside Cook Inlet were exceedingly rare, and these were composed of a 
few stragglers from the Cook Inlet DPS observed at Kodiak Island, 
Prince William Sound, and Yakutat Bay. Several marine mammal surveys 
specific to Cook Inlet (Laidre et al. 2000, Speckman and Piatt 2000), 
including those that concentrated on beluga whales (Rugh et al. 2000, 
2005a), clearly indicate that this stock largely confines itself to 
Cook Inlet. There is no indication that these whales make forays into 
the Bering Sea where they might intermix with other Alaskan stocks.
    The Cook Inlet beluga DPS was originally estimated at 1,300 whales 
in 1979 (Calkins 1989) and has been the focus of management concerns 
since experiencing a dramatic decline in the 1990s. Between 1994 and 
1998 the stock declined 47%, which has been attributed to 
overharvesting by subsistence hunting. During that period, subsistence 
hunting was estimated to have annually removed 10-15% of the 
population. Only five belugas have been harvested since 1999, yet the 
population has continued to decline (Allen and Angliss 2014), with the 
most recent estimate at only 312 animals (Allen and Angliss 2014). The 
NMFS listed the population as ``depleted'' in 2000 as a consequence of 
the decline, and as ``endangered'' under the ESA in 2008 when the 
population failed to recover following a moratorium on subsistence 
harvest. In April 2011, the NMFS designated critical habitat for the 
Cook Inlet beluga whale under the ESA (Figure 2 in the application).
    Prior to the decline, this DPS was believed to range throughout 
Cook Inlet and occasionally into Prince William Sound and Yakutat 
(Nemeth et al. 2007). However, the range has contracted coincident with 
the population reduction (Speckman and Piatt 2000). During the summer 
and fall, beluga whales are concentrated near the Susitna River mouth, 
Knik Arm, Turnagain Arm, and Chickaloon Bay (Nemeth et al. 2007) where 
they feed on migrating eulachon (Thaleichthys pacificus) and salmon 
(Onchorhynchus spp.) (Moore et al. 2000). The limits of Critical 
Habitat Area 1 reflect the summer distribution (Figure 3 in the 
application). During the winter, beluga whales concentrate in deeper 
waters in the mid-inlet to Kalgin Island, and in the shallow waters 
along the west shore of Cook Inlet to Kamishak Bay. The limits of 
Critical Habitat Area 2 reflect the winter distribution. Some whales 
may also winter in and near Kachemak Bay.
    Goetz et al. (2012) modeled beluga use in Cook Inlet based on the 
NMFS aerial surveys conducted between 1994 and 2008. The combined model 
results shown in Figure 3 in the application indicate a very clumped 
distribution of summering beluga whales, and that lower densities of 
belugas are expected to occur in most of the pipeline survey area (but 
not necessarily specific G&G survey locations; see Section 6.3 in the 
application) and the vicinity of the proposed Marine Terminal. However, 
Cook Inlet beluga whales begin moving into Knik Arm around August 15 
where they spend about a month feeding on Eagle River salmon. The area 
between Nikiski, Kenai, and Kalgin Island provides important wintering 
habitat for Cook Inlet beluga whales. Use of this area would be 
expected between fall and spring, with animals largely absent during 
the summer months when G&G surveys would occur (Goetz et al. 2012).

Killer Whale (Orcinus orca)

    Two different stocks of killer whales inhabit the Cook Inlet region 
of Alaska: The Alaska Resident Stock and the Gulf of Alaska, Aleutian 
Islands, Bering Sea Transient Stock (Allen and Angliss 2014). The 
Alaska Resident killer whale stock is estimated at 2,347 animals and 
occurs from Southeast Alaska to the Bering Sea (Allen and Angliss 
2014). Resident killer whales feed exclusively on fish and are 
genetically distinct from transient whales (Saulitis et al. 2000).
    The transient killer whales feed primarily on marine mammals 
(Saulitis et al. 2000). The transient population inhabiting the Gulf of 
Alaska shares mitochondrial DNA haplotypes with whales found along the 
Aleutian Islands and the Bering Sea, suggesting a common stock, 
although there appears to be some subpopulation genetic structuring 
occurring to suggest the gene flow between groups is limited (see Allen 
and Angliss 2014). For the three regions combined, the transient 
population has been estimated at 587 animals (Allen and Angliss 2014).
    Killer whales are occasionally observed in lower Cook Inlet, 
especially near Homer and Port Graham (Shelden

[[Page 50997]]

et al. 2003, Rugh et al. 2005a). The few whales that have been 
photographically identified in lower Cook Inlet belong to resident 
groups more commonly found in nearby Kenai Fjords and Prince William 
Sound (Shelden et al. 2003). Prior to the 1980s, killer whale sightings 
in upper Cook Inlet were very rare. During aerial surveys conducted 
between 1993 and 2004, killer whales were observed on only three 
flights, all in the Kachemak and English Bay area (Rugh et al. 2005a). 
However, anecdotal reports of killer whales feeding on belugas in upper 
Cook Inlet began increasing in the 1990s, possibly in response to 
declines in sea lion and harbor seal prey elsewhere (Shelden et al. 
2003). These sporadic ventures of transient killer whales into beluga 
summering grounds have been implicated as a possible contributor to the 
decline of Cook Inlet belugas in the 1990s, although the number of 
confirmed mortalities from killer whales is small (Shelden et al. 
2003). If killer whales were to venture into upper Cook Inlet in 2015, 
they might be encountered during the G&G Program.

Harbor Porpoise (Phocoena phocoena)

    Harbor porpoise are small (approximately 1.2 m [4 ft] in length), 
relatively inconspicuous toothed whales. The Gulf of Alaska Stock is 
distributed from Cape Suckling to Unimak Pass and was most recently 
estimated at 31,046 animals (Allen and Angliss 2014). They are found 
primarily in coastal waters less than 100 m (328 ft) deep (Hobbs and 
Waite 2010) where they feed on Pacific herring (Clupea pallasii), other 
schooling fishes, and cephalopods.
    Although they have been frequently observed during aerial surveys 
in Cook Inlet, most sightings of harbor porpoise are of single animals, 
and are concentrated at Chinitna and Tuxedni bays on the west side of 
lower Cook Inlet (Rugh et al. 2005a). Dahlheim et al. (2000) estimated 
the 1991 Cook Inlet-wide population at only 136 animals. Also, during 
marine mammal monitoring efforts conducted in upper Cook Inlet by 
Apache from 2012 to 2014, harbor porpoise represented less than 2% of 
all marine mammal sightings. However, they are one of the three marine 
mammals (besides belugas and harbor seals) regularly seen in upper Cook 
Inlet (Nemeth et al. 2007), especially during spring eulachon and 
summer salmon runs. Because harbor porpoise have been observed 
throughout Cook Inlet during the summer months, including mid-inlet 
waters, they represent species that might be encountered during G&G 
Program surveys in upper Cook Inlet.

Harbor Seal (Phoca vitulina)

    At over 150,000 animals state-wide (Allen and Angliss 2014), harbor 
seals are one of the more common marine mammal species in Alaskan 
waters. They are most commonly seen hauled out at tidal flats and rocky 
areas. Harbor seals feed largely on schooling fish such as Alaska 
Pollock, Pacific cod, salmon, Pacific herring, eulachon, and squid. 
Although harbor seals may make seasonal movements in response to prey, 
they are resident to Alaska and do not migrate.
    The Cook Inlet/Shelikof Stock, ranging from approximately Anchorage 
down along the south side of the Alaska Peninsula to Unimak Pass, has 
been recently estimated at a stable 22,900 (Allen and Angliss 2014). 
Large numbers concentrate at the river mouths and embayments of lower 
Cook Inlet, including the Fox River mouth in Kachemak Bay (Rugh et al. 
2005a). Montgomery et al. (2007) recorded over 200 haulout sites in 
lower Cook Inlet alone. However, only a few dozen to a couple hundred 
seals seasonally occur in upper Cook Inlet (Rugh et al. 2005a), mostly 
at the mouth of the Susitna River where their numbers vary with the 
spring eulachon and summer salmon runs (Nemeth et al. 2007, Boveng et 
al. 2012). Review of NMFS aerial survey data collected from 1993-2012 
(Shelden et al. 2013) finds that the annual high counts of seals hauled 
out in Cook Inlet ranged from about 100-380, with most of these animals 
hauling out at the mouths of the Theodore and Lewis Rivers. There are 
certainly thousands of harbor seals occurring in lower Cook Inlet, but 
no references have been found showing more than about 400 harbor seals 
occurring seasonally in upper Cook Inlet. In 2012, up to 100 harbor 
seals were observed hauled out at the mouths of the Theodore and Lewis 
rivers (located about 16 km [10 mi] northeast of the pipeline survey 
area) during monitoring activity associated with Apache's 2012 Cook 
Inlet seismic program, and harbor seals constituted 60 percent of all 
marine mammal sightings by Apache observers during 2012 to 2014 survey 
and monitoring efforts (L. Parker, Apache, pers. comm.). Montgomery et 
al. (2007) also found that seals elsewhere in Cook Inlet move in 
response to local steelhead (Onchorhynchus mykiss) and salmon runs. 
Harbor seals may be encountered during G&G surveys in Cook Inlet.

Humpback Whale (Megaptera novaeangliae)

    Although there is considerable distributional overlap in the 
humpback whale stocks that use Alaska, the whales seasonally found in 
lower Cook Inlet are probably of the Central North Pacific stock. 
Listed as endangered under the ESA, this stock has recently been 
estimated at 7,469, with the portion of the stock that feeds in the 
Gulf of Alaska estimated at 2,845 animals (Allen and Angliss 2014). The 
Central North Pacific stock winters in Hawaii and summers from British 
Columbia to the Aleutian Islands (Calambokidis et al. 1997), including 
Cook Inlet.
    Humpback use of Cook Inlet is largely confined to lower Cook Inlet. 
They have been regularly seen near Kachemak Bay during the summer 
months (Rugh et al. 2005a), and there is a whale-watching venture in 
Homer capitalizing on this seasonal event. There are anecdotal 
observations of humpback whales as far north as Anchor Point, with 
recent summer observations extending to Cape Starichkof (Owl Ridge 
2014). Because of the southern distribution of humpbacks in Cook Inlet, 
it is unlikely that they will be encountered during this activity in 
close enough proximity to cause Level B harassment. Therefore, no take 
is authorized for humpback whales.

Gray Whale (Eschrichtius robustus)

    Each spring, the Eastern North Pacific stock of gray whale migrates 
8,000 kilometers (5,000 miles) northward from breeding lagoons in Baja 
California to feeding grounds in the Bering and Chukchi seas, reversing 
their travel again in the fall (Rice and Wolman 1971). Their migration 
route is for the most part coastal until they reach the feeding 
grounds. A small portion of whales do not annually complete the full 
circuit, as small numbers can be found in the summer feeding along the 
Oregon, Washington, British Columbia, and Alaskan coasts (Rice et al. 
1984, Moore et al. 2007).
    Human exploitation reduced this stock to an estimated ``few 
thousand'' animals (Jones and Schwartz 2002). However, by the late 
1980s, the stock was appearing to reach carrying capacity and estimated 
to be at 26,600 animals (Jones and Schwartz 2002). By 2002, that stock 
had been reduced to about 16,000 animals, especially following 
unusually high mortality events in 1999 and 2000 (Allen and Angliss 
2014). The stock has continued to grow since then and is currently 
estimated at 19,126 animals with a minimum estimate of 18,017 (Carretta 
et al. 2013). Most gray whales migrate past

[[Page 50998]]

the mouth of Cook Inlet to and from northern feeding grounds. However, 
small numbers of summering gray whales have been noted by fisherman 
near Kachemak Bay and north of Anchor Point. Further, summering gray 
whales were seen offshore of Cape Starichkof by marine mammal observers 
monitoring Buccaneer's Cosmopolitan drilling program in 2013 (Owl Ridge 
2014). Regardless, gray whales are not expected to be encountered in 
upper Cook Inlet, where the activity is concentrated, north of Kachemak 
Bay. Therefore, it is unlikely that they will be encountered during 
this activity in close enough proximity to cause Level B harassment and 
are not considered further in this final Authorization notice.

Minke Whale (Balaenoptera acutorostrata)

    Minke whales are the smallest of the rorqual group of baleen whales 
reaching lengths of up to 35 feet. They are also the most common of the 
baleen whales, although there are no population estimates for the North 
Pacific, although estimates have been made for some portions of Alaska. 
Zerbini et al. (2006) estimated the coastal population between Kenai 
Fjords and the Aleutian Islands at 1,233 animals.
    During Cook Inlet-wide aerial surveys conducted from 1993 to 2004, 
minke whales were encountered only twice (1998, 1999), both times off 
Anchor Point 16 miles northwest of Homer. Recently, several minke 
whales were recorded off Cape Starichkof in early summer 2013 during 
exploratory drilling conducted there (Owl Ridge 2014). There are no 
records north of Cape Starichkof, and this species is unlikely to be 
seen in upper Cook Inlet. There is little chance of encountering a 
minke whale during these activities. Therefore, no take of minke whales 
is authorized.

Dall's Porpoise (Phocoenoides dalli)

    Dall's porpoise are widely distributed throughout the North Pacific 
Ocean including Alaska, although they are not found in upper Cook Inlet 
and the shallower waters of the Bering, Chukchi, and Beaufort Seas 
(Allen and Angliss 2014). Compared to harbor porpoise, Dall's porpoise 
prefer the deep offshore and shelf slope waters. The Alaskan population 
has been estimated at 83,400 animals (Allen and Angliss 2014), making 
it one of the more common cetaceans in the state. Dall's porpoise have 
been observed in lower Cook Inlet, including Kachemak Bay and near 
Anchor Point (Owl Ridge 2014), but sightings there are rare. The 
concentration of sightings of Dall's porpoise in a southerly part of 
the Inlet suggest it is unlikely they will be encountered during 
EMALL's activities. Therefore, no take of Dall's porpoise is 
authorized.

Steller Sea Lion (Eumetopias jubatus)

    The Western Stock of the Steller sea lion is defined as all 
populations west of longitude 144[deg] W. to the western end of the 
Aleutian Islands. The most recent estimate for this stock is 45,649 
animals (Allen and Angliss 2014), considerably less than that estimated 
140,000 animals in the 1950s (Merrick et al. 1987). Because of this 
dramatic decline, the stock was listed under the ESA as a threatened 
DPS in 1990, and relisted as endangered in 1997. Critical habitat was 
designated in 1993, and is defined as a 20-nautical-mile radius around 
all major rookeries and haulout sites. The 20-nautical-mile buffer was 
established based on telemetry data that indicated these sea lions 
concentrated their summer foraging effort within this distance of 
rookeries and haul outs.
    Steller sea lions inhabit lower Cook Inlet, especially in the 
vicinity of Shaw Island and Elizabeth Island (Nagahut Rocks) haulout 
sites (Rugh et al. 2005a), but are rarely seen in upper Cook Inlet 
(Nemeth et al. 2007). Of the 42 Steller sea lion groups recorded during 
Cook Inlet aerial surveys between 1993 and 2004, none were recorded 
north of Anchor Point and only one in the vicinity of Kachemak Bay 
(Rugh et al. 2005a). Marine mammal observers associated with 
Buccaneer's drilling project off Cape Starichkof did observe seven 
Steller sea lions during the summer of 2013 (Owl Ridge 2014).
    The upper reaches of Cook Inlet may not provide adequate foraging 
conditions for sea lions for establishing a major haul out presence. 
Steller sea lions feed largely on walleye pollock, salmon and 
arrowtooth flounder during the summer, and walleye pollock and Pacific 
cod during the winter (Sinclair and Zeppelin 2002), none of which, 
except for salmon, are found in abundance in upper Cook Inlet (Nemeth 
et al. 2007). Steller sea lions are unlikely to be encountered during 
operations in upper Cook Inlet, as they are primarily encountered along 
the Kenai Peninsula, especially closer to Anchor Point. Therefore, no 
take of Steller sea lion is authorized.

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components (seismic airgun operations, sub-bottom profiler chirper and 
boomer, vibracore) of the specified activity may impact marine mammals. 
The ``Estimated Take by Incidental Harassment'' section later in this 
document will include a quantitative analysis of the number of 
individuals that NMFS expects to be taken by this activity. The 
``Negligible Impact Analysis'' section will include the analysis of how 
this specific proposed activity would impact marine mammals and will 
consider the content of this section, the ``Estimated Take by 
Incidental Harassment'' section, the ``Mitigation'' section, and the 
``Anticipated Effects on Marine Mammal Habitat'' section to draw 
conclusions regarding the likely impacts of this activity on the 
reproductive success or survivorship of individuals and from that on 
the affected marine mammal populations or stocks.
    NMFS intends to provide a background of potential effects of 
EMALL's activities in this section. Operating active acoustic sources 
have the potential for adverse effects on marine mammals. The majority 
of anticipated impacts would be from the use of active acoustic 
sources.

Acoustic Impacts

    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Current 
data indicate that not all marine mammal species have equal hearing 
capabilities (Richardson et al., 1995; Southall et al., 1997; Wartzok 
and Ketten, 1999; Au and Hastings, 2008).
    Southall et al. (2007) designated ``functional hearing groups'' for 
marine mammals based on available behavioral data; audiograms derived 
from auditory evoked potentials; anatomical modeling; and other data. 
Southall et al. (2007) also estimated the lower and upper frequencies 
of functional hearing for each group. However, animals are less 
sensitive to sounds at the outer edges of their functional hearing 
range and are more sensitive to a range of frequencies within the 
middle of their functional hearing range.
    The functional groups and the associated frequencies are:
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing estimates occur between approximately 7 Hertz (Hz) 
and 25 kHz (extended from 22 kHz based on data indicating that some 
mysticetes can hear above 22 kHz; Au et al., 2006; Lucifredi and Stein, 
2007; Ketten and Mountain, 2009; Tubelli et al., 2012);

[[Page 50999]]

     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing estimates occur between 
approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): Functional hearing estimates occur between 
approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: Phocid (true seals) functional hearing 
estimates occur between approximately 75 Hz and 100 kHz (Hemila et al., 
2006; Mulsow et al., 2011; Reichmuth et al., 2013) and otariid (seals 
and sea lions) functional hearing estimates occur between approximately 
100 Hz to 40 kHz.
    As mentioned previously in this document, Cook Inlet beluga whales, 
harbor porpoise, killer whales, and harbor seals (3 odontocetes and 1 
phocid) would likely occur in the action area. Table 2 presents the 
classification of these species into their respective functional 
hearing group. NMFS consider a species' functional hearing group when 
analyzing the effects of exposure to sound on marine mammals.

 Table 2--Classification of Marine Mammals That Could Potentially Occur
 in the Proposed Activity Area in Cook Inlet, 2015 by Functional Hearing
                                  Group
                         [Southall et al., 2007]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Mid-Frequency Hearing Range...............  Beluga whale, killer whale.
High Frequency Hearing Range..............  Harbor porpoise.
Pinnipeds in Water Hearing Range..........  Harbor seal.
------------------------------------------------------------------------

1. Potential Effects of Airgun Sounds on Marine Mammals
    The effects of sounds from airgun operations might include one or 
more of the following: Tolerance, masking of natural sounds, behavioral 
disturbance, temporary or permanent impairment, or non-auditory 
physical or physiological effects (Richardson et al., 1995; Gordon et 
al., 2003; Nowacek et al., 2007; Southall et al., 2007). The effects of 
noise on marine mammals are highly variable, often depending on species 
and contextual factors (based on Richardson et al., 1995).

Tolerance

    Studies on marine mammals' tolerance to sound in the natural 
environment are relatively rare. Richardson et al. (1995) defined 
tolerance as the occurrence of marine mammals in areas where they are 
exposed to human activities or manmade noise. In many cases, tolerance 
develops by the animal habituating to the stimulus (i.e., the gradual 
waning of responses to a repeated or ongoing stimulus) (Richardson, et 
al., 1995), but because of ecological or physiological requirements, 
many marine animals may need to remain in areas where they are exposed 
to chronic stimuli (Richardson, et al., 1995).
    Numerous studies have shown that pulsed sounds from airguns are 
often readily detectable in the water at distances of many kilometers. 
Several studies have also shown that marine mammals at distances of 
more than a few kilometers from operating seismic vessels often show no 
apparent response. That is often true even in cases when the pulsed 
sounds must be readily audible to the animals based on measured 
received levels and the hearing sensitivity of the marine mammal group. 
Although various baleen whales and toothed whales, and (less 
frequently) pinnipeds have been shown to react behaviorally to airgun 
pulses under some conditions, at other times marine mammals of all 
three types have shown no overt reactions (Stone, 2003; Stone and 
Tasker, 2006; Moulton et al. 2005, 2006) and (MacLean and Koski, 2005; 
Bain and Williams, 2006).
    Weir (2008) observed marine mammal responses to seismic pulses from 
a 24 airgun array firing a total volume of either 5,085 in\3\ or 3,147 
in\3\ in Angolan waters between August 2004 and May 2005. Weir (2008) 
recorded a total of 207 sightings of humpback whales (n = 66), sperm 
whales (n = 124), and Atlantic spotted dolphins (n = 17) and reported 
that there were no significant differences in encounter rates 
(sightings per hour) for humpback and sperm whales according to the 
airgun array's operational status (i.e., active versus silent).
    Bain and Williams (2006) examined the effects of a large airgun 
array (maximum total discharge volume of 1,100 in \3\) on six species 
in shallow waters off British Columbia and Washington: Harbor seal, 
California sea lion, Steller sea lion, gray whale, Dall's porpoise, and 
harbor porpoise. Harbor porpoises showed reactions at received levels 
less than 155 dB re: 1 [mu]Pa at a distance of greater than 70 km (43 
mi) from the seismic source (Bain and Williams, 2006). However, the 
tendency for greater responsiveness by harbor porpoise is consistent 
with their relative responsiveness to boat traffic and some other 
acoustic sources (Richardson, et al., 1995; Southall, et al., 2007). In 
contrast, the authors reported that gray whales seemed to tolerate 
exposures to sound up to approximately 170 dB re: 1 [mu]Pa (Bain and 
Williams, 2006) and Dall's porpoises occupied and tolerated areas 
receiving exposures of 170-180 dB re: 1 [mu]Pa (Bain and Williams, 
2006; Parsons, et al., 2009). The authors observed several gray whales 
that moved away from the airguns toward deeper water where sound levels 
were higher due to propagation effects resulting in higher noise 
exposures (Bain and Williams, 2006). However, it is unclear whether 
their movements reflected a response to the sounds (Bain and Williams, 
2006). Thus, the authors surmised that the lack of gray whale responses 
to higher received sound levels were ambiguous at best because one 
expects the species to be the most sensitive to the low-frequency sound 
emanating from the airguns (Bain and Williams, 2006).
    Pirotta et al., (2014) observed short-term responses of harbor 
porpoises to a two-dimensional (2-D) seismic survey in an enclosed bay 
in northeast Scotland which did not result in broad-scale displacement. 
The harbor porpoises that remained in the enclosed bay area reduced 
their buzzing activity by 15 percent during the seismic survey 
(Pirotta, et al., 2014). Thus, the authors suggest that animals exposed 
to anthropogenic disturbance may make trade-offs between perceived 
risks and the cost of leaving disturbed areas (Pirotta, et al., 2014).

Masking

    Marine mammals use acoustic signals for a variety of purposes, 
which differ among species, but include communication between 
individuals, navigation, foraging, reproduction, avoiding predators, 
and learning about their environment (Erbe and Farmer, 2000; Tyack, 
2000).
    The term masking refers to the inability of an animal to recognize 
the occurrence of an acoustic stimulus because of interference of 
another acoustic stimulus (Clark et al., 2009). Thus, masking is the 
obscuring of sounds of interest by other sounds, often at similar 
frequencies. It is a phenomenon that affects animals that are trying to 
receive acoustic information about their environment, including sounds 
from other members of their species, predators, prey, and sounds that 
allow them to orient in their environment. Masking these acoustic 
signals can disturb the behavior of individual animals, groups of 
animals,

[[Page 51000]]

or entire populations in certain circumstances.
    Introduced underwater sound may, through masking, reduce the 
effective communication distance of a marine mammal species if the 
frequency of the source is close to that used as a signal by the marine 
mammal, and if the anthropogenic sound is present for a significant 
fraction of the time (Richardson et al., 1995).
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior through shifting call frequencies, 
increasing call volume, and increasing vocalization rates. For example 
in one study, blue whales increased call rates when exposed to noise 
from seismic surveys in the St. Lawrence Estuary (Di Iorio and Clark, 
2010). Other studies reported that some North Atlantic right whales 
exposed to high shipping noise increased call frequency (Parks et al., 
2007) and some humpback whales responded to low-frequency active sonar 
playbacks by increasing song length (Miller et al., 2000). 
Additionally, beluga whales change their vocalizations in the presence 
of high background noise possibly to avoid masking calls (Au et al., 
1985; Lesage et al., 1999; Scheifele et al., 2005).
    Studies have shown that some baleen and toothed whales continue 
calling in the presence of seismic pulses, and some researchers have 
heard these calls between the seismic pulses (e.g., McDonald et al., 
1995; Greene et al., 1999; Nieukirk et al., 2004; Smultea et al., 2004; 
Holst et al., 2005a, 2005b, 2006; and Dunn and Hernandez, 2009).
    In contrast, Clark and Gagnon (2006) reported that fin whales in 
the northeast Pacific Ocean went silent for an extended period starting 
soon after the onset of a seismic survey in the area. Similarly, NMFS 
is aware of one report that observed sperm whales ceased calls when 
exposed to pulses from a very distant seismic ship (Bowles et al., 
1994). However, more recent studies have found that sperm whales 
continued calling in the presence of seismic pulses (Madsen et al., 
2002; Tyack et al., 2003; Smultea et al., 2004; Holst et al., 2006; and 
Jochens et al., 2008).
    Risch et al., (2012) documented reductions in humpback whale 
vocalizations in the Stellwagen Bank National Marine Sanctuary 
concurrent with transmissions of the Ocean Acoustic Waveguide Remote 
Sensing (OAWRS) low-frequency fish sensor system at distances of 200 km 
(124 mi) from the source. The recorded OAWRS produced series of 
frequency modulated pulses and the signal received levels ranged from 
88 to 110 dB re: 1 [mu]Pa (Risch, et al., 2012). The authors 
hypothesized that individuals did not leave the area but instead ceased 
singing and noted that the duration and frequency range of the OAWRS 
signals (a novel sound to the whales) were similar to those of natural 
humpback whale song components used during mating (Risch et al., 2012). 
Thus, the novelty of the sound to humpback whales in the study area 
provided a compelling contextual probability for the observed effects 
(Risch et al., 2012). However, the authors did not state or imply that 
these changes had long-term effects on individual animals or 
populations (Risch et al., 2012).
    Several studies have also reported hearing dolphins and porpoises 
calling while airguns were operating (e.g., Gordon et al., 2004; 
Smultea et al., 2004; Holst et al., 2005a, b; and Potter et al., 2007). 
The sounds important to small odontocetes are predominantly at much 
higher frequencies than the dominant components of airgun sounds, thus 
limiting the potential for masking in those species.
    Although some degree of masking is inevitable when high levels of 
manmade broadband sounds are present in the sea, marine mammals have 
evolved systems and behavior that function to reduce the impacts of 
masking. Odontocete conspecifics may readily detect structured signals, 
such as the echolocation click sequences of small toothed whales even 
in the presence of strong background noise because their frequency 
content and temporal features usually differ strongly from those of the 
background noise (Au and Moore, 1988, 1990). The components of 
background noise that are similar in frequency to the sound signal in 
question primarily determine the degree of masking of that signal.
    Redundancy and context can also facilitate detection of weak 
signals. These phenomena may help marine mammals detect weak sounds in 
the presence of natural or manmade noise. Most masking studies in 
marine mammals present the test signal and the masking noise from the 
same direction. The sound localization abilities of marine mammals 
suggest that, if signal and noise come from different directions, 
masking would not be as severe as the usual types of masking studies 
might suggest (Richardson et al., 1995). The dominant background noise 
may be highly directional if it comes from a particular anthropogenic 
source such as a ship or industrial site. Directional hearing may 
significantly reduce the masking effects of these sounds by improving 
the effective signal-to-noise ratio. In the cases of higher frequency 
hearing by the bottlenose dolphin, beluga whale, and killer whale, 
empirical evidence confirms that masking depends strongly on the 
relative directions of arrival of sound signals and the masking noise 
(Penner et al., 1986; Dubrovskiy, 1990; Bain et al., 1993; Bain and 
Dahlheim, 1994). Toothed whales and probably other marine mammals as 
well, have additional capabilities besides directional hearing that can 
facilitate detection of sounds in the presence of background noise. 
There is evidence that some toothed whales can shift the dominant 
frequencies of their echolocation signals from a frequency range with a 
lot of ambient noise toward frequencies with less noise (Au et al., 
1974, 1985; Moore and Pawloski, 1990; Thomas and Turl, 1990; Romanenko 
and Kitain, 1992; Lesage et al., 1999). A few marine mammal species 
increase the source levels or alter the frequency of their calls in the 
presence of elevated sound levels (Dahlheim, 1987; Au, 1993; Lesage et 
al., 1993, 1999; Terhune, 1999; Foote et al., 2004; Parks et al., 2007, 
2009; Di Iorio and Clark, 2010; Holt et al., 2009).
    These data demonstrating adaptations for reduced masking pertain 
mainly to the very high frequency echolocation signals of toothed 
whales. There is less information about the existence of corresponding 
mechanisms at moderate or low frequencies or in other types of marine 
mammals. For example, Zaitseva et al. (1980) found that, for the 
bottlenose dolphin, the angular separation between a sound source and a 
masking noise source had little effect on the degree of masking when 
the sound frequency was 18 kHz, in contrast to the pronounced effect at 
higher frequencies. Studies have noted directional hearing at 
frequencies as low as 0.5-2 kHz in several marine mammals, including 
killer whales (Richardson et al., 1995a). This ability may be useful in 
reducing masking at these frequencies. In summary, high levels of sound 
generated by anthropogenic activities may act to mask the detection of 
weaker biologically important sounds by some marine mammals. This 
masking may be more prominent for lower frequencies. For higher 
frequencies, such as that used in echolocation by toothed whales, 
several mechanisms are available that may allow them to reduce the 
effects of such masking.

Behavioral Disturbance

    Marine mammals may behaviorally react to sound when exposed to 
anthropogenic noise. Reactions to

[[Page 51001]]

sound, if any, depend on species, state of maturity, experience, 
current activity, reproductive state, time of day, and many other 
factors (Richardson et al., 1995; D'Spain & Wartzok, 2004; Southall et 
al., 2007; Weilgart, 2007).
    Types of behavioral reactions can include the following: changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities; 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where noise sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haulouts or rookeries).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, one could expect the consequences 
of behavioral modification to be biologically significant if the change 
affects growth, survival, and/or reproduction (e.g., Lusseau and 
Bejder, 2007; Weilgart, 2007). Examples of behavioral modifications 
that could impact growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those associated with beaked whale stranding related to exposure to 
military mid-frequency tactical sonar);
     Permanent habitat abandonment due to loss of desirable 
acoustic environment; and
     Disruption of feeding or social interaction resulting in 
significant energetic costs, inhibited breeding, or cow-calf 
separation.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Richardson et 
al., 1995; Southall et al., 2007). Many studies have also shown that 
marine mammals at distances more than a few kilometers away often show 
no apparent response when exposed to seismic activities (e.g., Madsen & 
Mohl, 2000 for sperm whales; Malme et al., 1983, 1984 for gray whales; 
and Richardson et al., 1986 for bowhead whales). Other studies have 
shown that marine mammals continue important behaviors in the presence 
of seismic pulses (e.g., Dunn & Hernandez, 2009 for blue whales; Greene 
Jr. et al., 1999 for bowhead whales; Holst and Beland, 2010; Holst and 
Smultea, 2008; Holst et al., 2005; Nieukirk et al., 2004; Richardson, 
et al., 1986; Smultea et al., 2004).
    Baleen Whales: Studies have shown that underwater sounds from 
seismic activities are often readily detectable by baleen whales in the 
water at distances of many kilometers (Castellote et al., 2012 for fin 
whales).
    Observers have seen various species of Balaenoptera (blue, sei, 
fin, and minke whales) in areas ensonified by airgun pulses (Stone, 
2003; MacLean and Haley, 2004; Stone and Tasker, 2006), and have 
localized calls from blue and fin whales in areas with airgun 
operations (e.g., McDonald et al., 1995; Dunn and Hernandez, 2009; 
Castellote et al., 2010). Sightings by observers on seismic vessels off 
the United Kingdom from 1997 to 2000 suggest that, during times of good 
visibility, sighting rates for mysticetes (mainly fin and sei whales) 
were similar when large arrays of airguns were shooting versus silent 
(Stone, 2003; Stone and Tasker, 2006). However, these whales tended to 
exhibit localized avoidance, remaining significantly further (on 
average) from the airgun array during seismic operations compared with 
non-seismic periods (Stone and Tasker, 2006).
    Ship-based monitoring studies of baleen whales (including blue, 
fin, sei, minke, and humpback whales) in the northwest Atlantic found 
that overall, this group had lower sighting rates during seismic versus 
non-seismic periods (Moulton and Holst, 2010). The authors observed 
that baleen whales as a group were significantly farther from the 
vessel during seismic compared with non-seismic periods. Moreover, the 
authors observed that the whales swam away more often from the 
operating seismic vessel (Moulton and Holst, 2010). Initial sightings 
of blue and minke whales were significantly farther from the vessel 
during seismic operations compared to non-seismic periods and the 
authors observed the same trend for fin whales (Moulton and Holst, 
2010). Also, the authors observed that minke whales most often swam 
away from the vessel when seismic operations were underway (Moulton and 
Holst, 2010).
    Toothed Whales: Few systematic data are available describing 
reactions of toothed whales to noise pulses. However, systematic work 
on sperm whales is underway (e.g., Gordon et al., 2006; Madsen et al., 
2006; Winsor and Mate, 2006; Jochens et al., 2008; Miller et al., 2009) 
and there is an increasing amount of information about responses of 
various odontocetes, including killer whales and belugas, to seismic 
surveys based on monitoring studies (e.g., Stone, 2003; Smultea et al., 
2004; Moulton and Miller, 2005; Bain and Williams, 2006; Holst et al., 
2006; Stone and Tasker, 2006; Potter et al., 2007; Hauser et al., 2008; 
Holst and Smultea, 2008; Weir, 2008; Barkaszi et al., 2009; Richardson 
et al., 2009; Moulton and Holst, 2010). Reactions of toothed whales to 
large arrays of airguns are variable and, at least for delphinids, seem 
to be confined to a smaller radius than has been observed for 
mysticetes.
    Observers stationed on seismic vessels operating off the United 
Kingdom from 1997-2000 have provided data on the occurrence and 
behavior of various toothed whales exposed to seismic pulses (Stone, 
2003; Gordon et al., 2004). The studies note that killer whales were 
significantly farther from large airgun arrays during periods of active 
airgun operations compared with periods of silence. The displacement of 
the median distance from the array was approximately 0.5 km (0.3 mi) or 
more. Killer whales also appear to be more tolerant of seismic shooting 
in deeper water (Stone, 2003; Gordon et al., 2004).
    The beluga may be a species that (at least in certain geographic 
areas) shows long-distance avoidance of seismic vessels. Aerial surveys 
during seismic operations in the southeastern Beaufort Sea recorded 
much lower sighting rates of beluga whales within 10-20 km (6.2-12.4 
mi) of an active seismic vessel. These results were consistent with the 
low number of beluga sightings reported by observers aboard the seismic 
vessel, suggesting that some belugas might have been avoiding the 
seismic operations at distances of 10-20 km (6.2-12.4 mi) (Miller et 
al., 2005).

Delphinids

    Seismic operators and protected species observers (observers) on 
seismic vessels regularly see dolphins and other small toothed whales 
near operating airgun arrays, but in general there is a tendency for 
most delphinids to show some avoidance of operating seismic vessels 
(e.g., Goold, 1996a,b,c; Calambokidis and Osmek, 1998; Stone, 2003; 
Moulton and Miller, 2005; Holst et al., 2006; Stone and Tasker, 2006; 
Weir, 2008; Richardson et al., 2009; Barkaszi et al., 2009; Moulton and 
Holst, 2010). Some dolphins seem to be attracted to the seismic vessel 
and floats, and some ride the bow wave of the seismic vessel even when 
large arrays of airguns are firing (e.g., Moulton and Miller, 2005). 
Nonetheless, there have been indications that small toothed whales 
sometimes move away or maintain a somewhat greater distance from the 
vessel when a large array of

[[Page 51002]]

airguns is operating than when it is silent (e.g., Goold, 1996a,b,c; 
Stone and Tasker, 2006; Weir, 2008; Moulton and Holst, 2010). In most 
cases, the avoidance radii for delphinids appear to be small, on the 
order of one km or less, and some individuals show no apparent 
avoidance.
    Captive bottlenose dolphins exhibited changes in behavior when 
exposed to strong pulsed sounds similar in duration to those typically 
used in seismic surveys (Finneran et al., 2000, 2002, 2005). However, 
the animals tolerated high received levels of sound (pk-pk level >200 
dB re 1 [mu]Pa) before exhibiting aversive behaviors.

Porpoises

    Results for porpoises depend upon the species. The limited 
available data suggest that harbor porpoises show stronger avoidance of 
seismic operations than do Dall's porpoises (Stone, 2003; MacLean and 
Koski, 2005; Bain and Williams, 2006; Stone and Tasker, 2006). Dall's 
porpoises seem relatively tolerant of airgun operations (MacLean and 
Koski, 2005; Bain and Williams, 2006), although they too have been 
observed to avoid large arrays of operating airguns (Calambokidis and 
Osmek, 1998; Bain and Williams, 2006). This apparent difference in 
responsiveness of these two porpoise species is consistent with their 
relative responsiveness to boat traffic and some other acoustic sources 
(Richardson et al., 1995; Southall et al., 2007).

Pinnipeds

    Pinnipeds are not likely to show a strong avoidance reaction to the 
airgun sources proposed for use. Visual monitoring from seismic vessels 
has shown only slight (if any) avoidance of airguns by pinnipeds and 
only slight (if any) changes in behavior. Monitoring work in the 
Alaskan Beaufort Sea during 1996-2001 provided considerable information 
regarding the behavior of Arctic ice seals exposed to seismic pulses 
(Harris et al., 2001; Moulton and Lawson, 2002). These seismic projects 
usually involved arrays of 6 to 16 airguns with total volumes of 560 to 
1,500 in \3\. The combined results suggest that some seals avoid the 
immediate area around seismic vessels. In most survey years, ringed 
seal (Phoca hispida) sightings tended to be farther away from the 
seismic vessel when the airguns were operating than when they were not 
(Moulton and Lawson, 2002). However, these avoidance movements were 
relatively small, on the order of 100 m (328 ft) to a few hundreds of 
meters, and many seals remained within 100-200 m (328-656 ft) of the 
trackline as the operating airgun array passed by the animals. Seal 
sighting rates at the water surface were lower during airgun array 
operations than during no-airgun periods in each survey year except 
1997. Similarly, seals are often very tolerant of pulsed sounds from 
seal-scaring devices (Mate and Harvey, 1987; Jefferson and Curry, 1994; 
Richardson et al., 1995). However, initial telemetry work suggests that 
avoidance and other behavioral reactions by two other species of seals 
to small airgun sources may at times be stronger than evident to date 
from visual studies of pinniped reactions to airguns (Thompson et al., 
1998).

Hearing Impairment

    Exposure to high intensity sound for a sufficient duration may 
result in auditory effects such as a noise-induced threshold shift--an 
increase in the auditory threshold after exposure to noise (Finneran et 
al., 2005). Factors that influence the amount of threshold shift 
include the amplitude, duration, frequency content, temporal pattern, 
and energy distribution of noise exposure. The magnitude of hearing 
threshold shift normally decreases over time following cessation of the 
noise exposure. The amount of threshold shift just after exposure is 
the initial threshold shift. If the threshold shift eventually returns 
to zero (i.e., the threshold returns to the pre-exposure value), it is 
a temporary threshold shift (Southall et al., 2007).
    Threshold Shift (noise-induced loss of hearing)--When animals 
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an 
animal to detect them) following exposure to an intense sound or sound 
for long duration, it is referred to as a noise-induced threshold shift 
(TS). An animal can experience temporary threshold shift (TTS) or 
permanent threshold shift (PTS). TTS can last from minutes or hours to 
days (i.e., there is complete recovery), can occur in specific 
frequency ranges (i.e., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is 
permanent, but some recovery is possible. PTS can also occur in a 
specific frequency range and amount as mentioned above for TTS.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased blood flow, and 
post-stimulatory reduction in both efferent and sensory neural output 
(Southall et al., 2007). The amplitude, duration, frequency, temporal 
pattern, and energy distribution of sound exposure all can affect the 
amount of associated TS and the frequency range in which it occurs. As 
amplitude and duration of sound exposure increase, so, generally, does 
the amount of TS, along with the recovery time. For intermittent 
sounds, less TS could occur than compared to a continuous exposure with 
the same energy (some recovery could occur between intermittent 
exposures depending on the duty cycle between sounds) (Kryter et al., 
1966; Ward, 1997). For example, one short but loud (higher SPL) sound 
exposure may induce the same impairment as one longer but softer sound, 
which in turn may cause more impairment than a series of several 
intermittent softer sounds with the same total energy (Ward, 1997). 
Additionally, though TTS is temporary, prolonged exposure to sounds 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985). Although in the case of EMALL'ssurvey, NMFS 
does not expect that animals would experience levels high enough or 
durations long enough to result in PTS given that the airgun is a very 
low volume airgun, and the use of the airgun will be restricted to 
seven days in a small geographic area.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS; however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in non-human animals.
    Recent studies by Kujawa and Liberman (2009) and Lin et al. (2011) 
found that despite completely reversible threshold shifts that leave 
cochlear sensory cells intact, large threshold shifts could cause 
synaptic level changes and delayed cochlear nerve

[[Page 51003]]

degeneration in mice and guinea pigs, respectively. NMFS notes that the 
high level of TTS that led to the synaptic changes shown in these 
studies is in the range of the high degree of TTS that Southall et al. 
(2007) used to calculate PTS levels. It is unknown whether smaller 
levels of TTS would lead to similar changes. NMFS, however, 
acknowledges the complexity of noise exposure on the nervous system, 
and will re-examine this issue as more data become available.
    For marine mammals, published data are limited to the captive 
bottlenose dolphin, beluga, harbor porpoise, and Yangtze finless 
porpoise (Finneran et al., 2000, 2002, 2003, 2005, 2007, 2010a, 2010b; 
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et 
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data 
are limited to measurements of TTS in harbor seals, an elephant seal, 
and California sea lions (Kastak et al., 1999, 2005; Kastelein et al., 
2012b).
    Lucke et al. (2009) found a threshold shift (TS) of a harbor 
porpoise after exposing it to airgun noise with a received sound 
pressure level (SPL) at 200.2 dB (peak-to-peak) re: 1 [mu]Pa, which 
corresponds to a sound exposure level of 164.5 dB re: 1 [mu]Pa2 s after 
integrating exposure. NMFS currently uses the root-mean-square (rms) of 
received SPL at 180 dB and 190 dB re: 1 [mu]Pa as the threshold above 
which permanent threshold shift (PTS) could occur for cetaceans and 
pinnipeds, respectively. Because the airgun noise is a broadband 
impulse, one cannot directly determine the equivalent of rms SPL from 
the reported peak-to-peak SPLs. However, applying a conservative 
conversion factor of 16 dB for broadband signals from seismic surveys 
(McCauley, et al., 2000) to correct for the difference between peak-to-
peak levels reported in Lucke et al. (2009) and rms SPLs, the rms SPL 
for TTS would be approximately 184 dB re: 1 [mu]Pa, and the received 
levels associated with PTS (Level A harassment) would be higher. This 
is still above NMFS' current 180 dB rms re: 1 [mu]Pa threshold for 
injury. However, NMFS recognizes that TTS of harbor porpoises is lower 
than other cetacean species empirically tested (Finneran & Schlundt, 
2010; Finneran et al., 2002; Kastelein and Jennings, 2012).
    A recent study on bottlenose dolphins (Schlundt, et al., 2013) 
measured hearing thresholds at multiple frequencies to determine the 
amount of TTS induced before and after exposure to a sequence of 
impulses produced by a seismic air gun. The air gun volume and 
operating pressure varied from 40-150 in\3\ and 1000-2000 psi, 
respectively. After three years and 180 sessions, the authors observed 
no significant TTS at any test frequency, for any combinations of air 
gun volume, pressure, or proximity to the dolphin during behavioral 
tests (Schlundt, et al., 2013). Schlundt et al. (2013) suggest that the 
potential for airguns to cause hearing loss in dolphins is lower than 
previously predicted, perhaps as a result of the low-frequency content 
of air gun impulses compared to the high-frequency hearing ability of 
dolphins.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
(similar to those discussed in auditory masking, below). For example, a 
marine mammal may be able to readily compensate for a brief, relatively 
small amount of TTS in a non-critical frequency range that occurs 
during a time where ambient noise is lower and there are not as many 
competing sounds present. Alternatively, a larger amount and longer 
duration of TTS sustained during time when communication is critical 
for successful mother/calf interactions could have more serious 
impacts. Also, depending on the degree and frequency range, the effects 
of PTS on an animal could range in severity, although it is considered 
generally more serious because it is a permanent condition. Of note, 
reduced hearing sensitivity as a simple function of aging has been 
observed in marine mammals, as well as humans and other taxa (Southall 
et al., 2007), so one can infer that strategies exist for coping with 
this condition to some degree, though likely not without cost.
    Given the higher level of sound necessary to cause PTS as compared 
with TTS, it is considerably less likely that PTS would occur during 
the survey; TTS is also unlikely. Cetaceans generally avoid the 
immediate area around operating seismic vessels, as do some other 
marine mammals. Some pinnipeds show avoidance reactions to airguns, but 
their avoidance reactions are generally not as strong or consistent 
compared to cetacean reactions.
    Non-auditory Physical Effects: Non-auditory physical effects might 
occur in marine mammals exposed to strong underwater pulsed sound. 
Possible types of non-auditory physiological effects or injuries that 
theoretically might occur in mammals close to a strong sound source 
include stress, neurological effects, bubble formation, and other types 
of organ or tissue damage. Some marine mammal species (i.e., beaked 
whales) may be especially susceptible to injury and/or stranding when 
exposed to strong pulsed sounds.
    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: Behavioral responses; 
autonomic nervous system responses; neuroendocrine responses; or immune 
responses.
    In the case of many stressors, an animal's first and most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response, which includes the cardiovascular system, 
the gastrointestinal system, the exocrine glands, and the adrenal 
medulla to produce changes in heart rate, blood pressure, and 
gastrointestinal activity that humans commonly associate with stress. 
These responses have a relatively short duration and may or may not 
have significant long-term effects on an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine or sympathetic nervous systems; the system that has 
received the most study has been the hypothalmus-pituitary-adrenal 
(HPA) system (also known as the HPA axis in mammals or the 
hypothalamus-pituitary-interrenal axis in fish and some reptiles). 
Unlike stress responses associated with the autonomic nervous system, 
the pituitary hormones regulate virtually all neuroendocrine functions 
affected by stress--including immune competence, reproduction, 
metabolism, and behavior. Stress-induced changes in the secretion of 
pituitary hormones have been implicated in failed reproduction (Moberg, 
1987; Rivier, 1995), altered metabolism (Elasser et al., 2000), reduced 
immune competence (Blecha, 2000), and behavioral disturbance.

[[Page 51004]]

Increases in the circulation of glucocorticosteroids (cortisol, 
corticosterone, and aldosterone in marine mammals; see Romano et al., 
2004) have been equated with stress for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that the body quickly replenishes after alleviation of the 
stressor. In such circumstances, the cost of the stress response would 
not pose a risk to the animal's welfare. However, when an animal does 
not have sufficient energy reserves to satisfy the energetic costs of a 
stress response, it diverts energy resources from other biotic 
functions, which impair those functions that experience the diversion. 
For example, when mounting a stress response diverts energy away from 
growth in young animals, those animals may experience stunted growth 
(McEwen and Wingfield, 2003). When mounting a stress response diverts 
energy from a fetus, an animal's reproductive success and fitness will 
suffer. In these cases, the animals will have entered a pre-
pathological or pathological state called ``distress'' (sensu Seyle, 
1950) or ``allostatic loading'' (sensu McEwen and Wingfield, 2003). 
This pathological state will last until the animal replenishes its 
biotic reserves sufficient to restore normal function. Note that these 
examples involved a long-term (days or weeks) stress response exposure 
to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiment; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Although no information has been collected on the physiological 
responses of marine mammals to anthropogenic sound exposure, studies of 
other marine animals and terrestrial animals would lead us to expect 
some marine mammals to experience physiological stress responses and, 
perhaps, physiological responses that would be classified as 
``distress'' upon exposure to anthropogenic sounds.
    For example, Jansen (1998) reported on the relationship between 
acoustic exposures and physiological responses that are indicative of 
stress responses in humans (e.g., elevated respiration and increased 
heart rates). Jones (1998) reported on reductions in human performance 
when faced with acute, repetitive exposures to acoustic disturbance. 
Trimper et al. (1998) reported on the physiological stress responses of 
osprey to low-level aircraft noise while Krausman et al. (2004) 
reported on the auditory and physiology stress responses of endangered 
Sonoran pronghorn to military overflights. Smith et al. (2004a, 2004b) 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
and behavioral stress responses that accompanied damage to the inner 
ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and communicate with conspecifics. 
Although empirical information on the relationship between sensory 
impairment (TTS, PTS, and acoustic masking) on marine mammals remains 
limited, we assume that reducing a marine mammal's ability to gather 
information about its environment and communicate with other members of 
its species would induce stress, based on data that terrestrial animals 
exhibit those responses under similar conditions (NRC, 2003) and 
because marine mammals use hearing as their primary sensory mechanism. 
Therefore, NMFS assumes that acoustic exposures sufficient to trigger 
onset PTS or TTS would be accompanied by physiological stress 
responses. More importantly, marine mammals might experience stress 
responses at received levels lower than those necessary to trigger 
onset TTS. Based on empirical studies of the time required to recover 
from stress responses (Moberg, 2000), NMFS also assumes that stress 
responses could persist beyond the time interval required for animals 
to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral 
responses to TTS.
    Resonance effects (Gentry, 2002) and direct noise-induced bubble 
formations (Crum et al., 2005) are implausible in the case of exposure 
to an impulsive broadband source like an airgun array. If seismic 
surveys disrupt diving patterns of deep-diving species, this might 
result in bubble formation and a form of the bends, as speculated to 
occur in beaked whales exposed to sonar. However, there is no specific 
evidence of this upon exposure to airgun pulses.
    In general, there are few data about the potential for strong, 
anthropogenic underwater sounds to cause non-auditory physical effects 
in marine mammals. Such effects, if they occur at all, would presumably 
be limited to short distances and to activities that extend over a 
prolonged period. The available data do not allow identification of a 
specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. There is no definitive evidence that any of 
these effects occur even for marine mammals in close proximity to large 
arrays of airguns. In addition, marine mammals that show behavioral 
avoidance of seismic vessels, including some pinnipeds, are unlikely to 
incur non-auditory impairment or other physical effects. The low volume 
of the airgun proposed for this activity combined with the limited 
scope of use makes non-auditory physical effects from airgun use, 
including stress, unlikely. Therefore, we do not anticipate such 
effects would occur given the brief duration of exposure during the 
survey.

Stranding and Mortality

    When a living or dead marine mammal swims or floats onto shore and 
becomes ``beached'' or incapable of returning to sea, the event is a 
``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; Geraci and 
Lounsbury, 2005; NMFS, 2007). The legal definition for a stranding 
under the MMPA is that ``(A) a marine mammal is dead and is (i) on a 
beach or shore of the United States; or (ii) in waters under the 
jurisdiction of the United States (including any navigable waters); or 
(B) a marine mammal is alive and is (i) on a beach or shore of the 
United States and is unable to return to the water; (ii) on a beach or 
shore of the United States and, although able to return to the water, 
is in need of apparent medical attention; or (iii) in the waters under 
the jurisdiction of the United States (including any navigable waters), 
but is unable to return to its natural habitat under its own power or 
without assistance.''
    Marine mammals strand for a variety of reasons, such as infectious 
agents, biotoxicosis, starvation, fishery interaction, ship strike, 
unusual oceanographic or weather events, sound exposure, or 
combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of

[[Page 51005]]

most strandings are unknown (Geraci et al., 1976; Eaton, 1979; Odell et 
al., 1980; Best, 1982). Numerous studies suggest that the physiology, 
behavior, habitat relationships, age, or condition of cetaceans may 
cause them to strand or might pre-dispose them to strand when exposed 
to another phenomenon. These suggestions are consistent with the 
conclusions of numerous other studies that have demonstrated that 
combinations of dissimilar stressors commonly combine to kill an animal 
or dramatically reduce its fitness, even though one exposure without 
the other does not produce the same result (Chroussos, 2000; Creel, 
2005; DeVries et al., 2003; Fair and Becker, 2000; Foley et al., 2001; 
Moberg, 2000; Relyea, 2005a; 2005b, Romero, 2004; Sih et al., 2004). 
Given the low volume and source level of the proposed airgun, standing 
and mortality are not anticipated due to use of the airgun proposed for 
this activity.
2. Potential Effects of Other Acoustic Devices

Sub-Bottom Profiler

    EMALL would also operate a sub-bottom profiler chirp and boomer 
from the source vessel during the proposed survey. The chirp's sounds 
are very short pulses, occurring for one ms, six times per second. Most 
of the energy in the sound pulses emitted by the profiler is at 2-6 
kHz, and the beam is directed downward. The chirp has a maximum source 
level of 202 dB re: 1 [micro]Pa, with a tilt angle of 90 degrees below 
horizontal and a beam width of 24 degrees. The sub-bottom profiler 
boomer will shoot approximately every 3.125m, with shots lasting 1.5 to 
2 seconds. Most of the energy in the sound pulses emitted by the boomer 
is concentrated between 0.5 and 6 kHz, with a source level of 205dB re: 
1[micro]Pa. The tilt of the boomer is 90 degrees below horizontal, but 
the emission is omnidirectional. Kremser et al., (2005) noted that the 
probability of a cetacean swimming through the area of exposure when a 
bottom profiler emits a pulse is small--because if the animal was in 
the area, it would have to pass the transducer at close range in order 
to be subjected to sound levels that could cause temporary threshold 
shift and would likely exhibit avoidance behavior to the area near the 
transducer rather than swim through at such a close range.
    Masking: Both the chirper and boomer sub-bottom profilers produce 
impulsive sound exceeding 160 dB re 1 [mu]Pa-m (rms). The louder boomer 
operates at a source value of 205 dB re 1 [mu]Pa-m (rms), but with a 
frequency between 0.5 and 6 kHz, which is lower than the maximum 
sensitivity hearing range of any the local species (belugas--40-130 
kHz;, killer whales--7-30 kHz; harbor porpoise--100-140 kHz; and harbor 
seals--10-30 kHz; Wartzok and Ketten 1999, Southall et al. 2007, 
Kastelein et al. 2002). While the chirper is not as loud (202 dB re 1 
[mu]Pa-m [rms]), it does operate at a higher frequency range (2-16 
kHz), and within the maximum sensitive range of all of the local 
species except beluga whales.
    Marine mammal communications would not likely be masked appreciably 
by the profiler's signals given the directionality of the signal and 
the brief period when an individual mammal is likely to be within its 
beam. Furthermore, despite the fact that the profiler overlaps with 
hearing ranges of many marine mammal species in the area, the 
profiler's signals do not overlap with the predominant frequencies in 
the calls, which would avoid significant masking.
    Behavioral Responses: Responses to the profiler are likely to be 
similar to the other pulsed sources discussed earlier if received at 
the same levels. The behavioral response of local marine mammals to the 
operation of the sub-bottom profilers is expected to be similar to that 
of the small airgun. The odontocetes are likely to avoid the sub-bottom 
profiler activity, especially the naturally shy harbor porpoise, while 
the harbor seals might be attracted to them out of curiosity. However, 
because the sub-bottom profilers operate from a moving vessel, and the 
maximum radius to the 160 dB harassment threshold is only 263 m (863 
ft), the area and time that this equipment would be affecting a given 
location is very small.
    Hearing Impairment and Other Physical Effects: It is unlikely that 
the sub-bottom profilers produce sound levels strong enough to cause 
hearing impairment or other physical injuries even in an animal that is 
(briefly) in a position near the source (Wood et al., 2012). The 
likelihood of marine mammals moving away from the source make if 
further unlikely that a marine mammal would be able to approach close 
to the transducers.
    Animals may avoid the area around the survey vessels, thereby 
reducing exposure. Any disturbance to marine mammals is likely to be in 
the form of temporary avoidance or alteration of opportunistic foraging 
behavior near the survey location.

Vibracore

    EMALL would conduct vibracoring in a corridor across a northern 
portion of Cook Inlet and near the marine terminal area for a total of 
55 vibracoring occurrences. While duration is dependent on sediment 
type, the driving mechanism, which emits sound at a source level of 
187dB re: 1[micro]Pa, will only bore for 1 to 2 minutes. The sound is 
emitted at a frequency of 10 Hz to 20 kHz. Cores will be bored at 
approximately every 4 km along the pipeline corridor, for about 22 
cores in that area. Approximately 33 cores will be taken in the Marine 
Terminal area.
    Masking: It is unlikely that masking will occur due to vibracore 
operations. Chorney et al. (2011) conducted sound measurements on an 
operating vibracorer in Alaska and found that it emitted a sound 
pressure level at 1-m source of 188 dB re 1 [mu]Pa-m (rms), with a 
frequency range of between 10 Hz and 20 kHz. While the frequency range 
overlaps the lower ends of the maximum sensitivity hearing ranges of 
harbor porpoises, killer whales, and harbor seals, and the continuous 
sound extends 2.54 km (1.6 mi) to the 120 dB threshold, the vibracorer 
will operate about the one or two minutes it takes to drive the core 
pipe 7 m (20 ft) into the sediment, and approximately twice per day. 
Therefore, there is very little opportunity for this activity to mask 
the communication of local marine mammals.
    Behavioral Response: It is unlikely that vibracoring will elicit 
behavioral responses from marine mammal species in the area. An 
analysis of similar survey activity in New Zealand classified the 
likely effects from vibracore and similar activity to be some habitat 
degradation and prey species effects, but primarily behavioral 
responses, although the species in the analyzed area were different to 
those found in Cook Inlet (Thompson, 2012).
    There are no data on the behavioral response to vibracore activity 
of marine mammals in Cook Inlet. The closest analog to vibracoring 
might be exploratory drilling, although there is a notable difference 
in magnitude between an oil and gas drilling operation and collecting 
sediment samples with a vibracorer. Thomas et al. (1990) played back 
drilling sound to four captive beluga whales and found no statistical 
difference in swim patterns, social groups, respiration and dive rates, 
or stress hormone levels before and during playbacks. There is no 
reason to believe that beluga whales or any other marine mammal exposed 
to vibracoring sound would behave any differently, especially since 
vibracoring occurs for only one or two minutes.
    Hearing Impairment and Other Physical Effects: The vibracorer 
operates for only one or two minutes at a time with a 1-m source of 
187.4 dB re 1 [mu]Pa-

[[Page 51006]]

m (rms). It is neither loud enough nor does it operate for a long 
enough duration to induce either TTS or PTS.

Stranding and Mortality

    Stress, Stranding, and Mortality Safety zones will be established 
to prevent acoustical injury to local marine mammals, especially injury 
that could indirectly lead to mortality. Also, G&G sound is not 
expected to cause resonate effects to gas-filled spaces or airspaces in 
marine mammals based on the research of Finneran (2003) on beluga 
whales showing that the tissue and other body masses dampen any 
potential effects of resonance on ear cavities, lungs, and intestines. 
Chronic exposure to sound could lead to physiological stress eventually 
causing hormonal imbalances (NRC 2005). If survival demands are already 
high, and/or additional stressors are present, the ability of the 
animal to cope decreases, leading to pathological conditions or death 
(NRC 2005). Potential effects may be greatest where sound disturbance 
can disrupt feeding patterns including displacement from critical 
feeding grounds. However, all G&G exposure to marine mammals would be 
of duration measured in minutes.
    Specific sound-related processes that lead to strandings and 
mortality are not well documented, but may include (1) swimming in 
avoidance of a sound into shallow water; (2) a change in behavior (such 
as a change in diving behavior) that might contribute to tissue damage, 
gas bubble formation, hypoxia, cardiac arrhythmia, hypertensive 
hemorrhage, or other forms of trauma; (3) a physiological change such 
as a vestibular response leading to a behavioral change or stress-
induced hemorrhagic diathesis, leading in turn to tissue damage; and, 
(4) tissue damage directly from sound exposure, such as through 
acoustically mediated bubble formation and growth or acoustic resonance 
of tissues (Wood et al. 2012). Some of these mechanisms are unlikely to 
apply in the case of impulse G&G sounds, especially since airguns and 
sub-bottom profilers produce broadband sound with low pressure rise. 
Strandings to date which have been attributed to sound exposure related 
to date from military exercises using narrowband mid-frequency sonar 
with a much greater likelihood to cause physical damage (Balcomb and 
Claridge 2001, NOAA and USN, 2001, Hildebrand 2005).
    The low intensity, low frequency, broadband sound associated with 
airguns and sub-bottom profilers, combined with the shutdown safety 
zone mitigation measure for the airgun would prevent physical damage to 
marine mammals. The vibracoring would also be unlikely to have the 
capability of causing physical damage to marine mammals because of its 
low intensity and short duration.
3. Potential Effects of Vessel Movement and Collisions
    Vessel movement in the vicinity of marine mammals has the potential 
to result in either a behavioral response or a direct physical 
interaction. We discuss both scenarios here.
    Behavioral Responses to Vessel Movement: There are limited data 
concerning marine mammal behavioral responses to vessel traffic and 
vessel noise, and a lack of consensus among scientists with respect to 
what these responses mean or whether they result in short-term or long-
term adverse effects. In those cases where there is a busy shipping 
lane or where there is a large amount of vessel traffic, marine mammals 
may experience acoustic masking (Hildebrand, 2005) if they are present 
in the area (e.g., killer whales in Puget Sound; Foote et al., 2004; 
Holt et al., 2008). In cases where vessels actively approach marine 
mammals (e.g., whale watching or dolphin watching boats), scientists 
have documented that animals exhibit altered behavior such as increased 
swimming speed, erratic movement, and active avoidance behavior (Bursk, 
1983; Acevedo, 1991; Baker and MacGibbon, 1991; Trites and Bain, 2000; 
Williams et al., 2002; Constantine et al., 2003), reduced blow interval 
(Ritcher et al., 2003), disruption of normal social behaviors (Lusseau, 
2003; 2006), and the shift of behavioral activities which may increase 
energetic costs (Constantine et al., 2003; 2004). A detailed review of 
marine mammal reactions to ships and boats is available in Richardson 
et al. (1995). For each of the marine mammal taxonomy groups, 
Richardson et al. (1995) provides the following assessment regarding 
reactions to vessel traffic:
    Pinnipeds: Reactions by pinnipeds to vessel disturbance largely 
involve relocation. Harbor seals hauled out on mud flats have been 
documented returning to the water in response to nearing boat traffic. 
Vessels that approach haulouts slowly may also elicit alert reactions 
without flushing from the haulout. Small boats with slow, constant 
speed elicit the least noticeable reactions. However, in Alaska 
specifically, harbor seals are documented to tolerate fishing vessels 
with no discernable reactions, and habituation is common (Burns in 
Johnson et al., 1989).
    Porpoises: Harbor porpoises are often seen changing direction in 
the presence of vessel traffic. Avoidance has been documented up to 1km 
away from an approaching vessel, but the avoidance response is 
strengthened in closer proximity to vessels (Barlow, 1998; Palka, 
1993). This avoidance behavior is not consistent across all porpoises, 
as Dall's porpoises have been observed approaching boats.
    Toothed whales: In summary, toothed whales sometimes show no 
avoidance reaction to vessels, or even approach them. However, 
avoidance can occur, especially in response to vessels of types used to 
chase or hunt the animals. This may cause temporary displacement, but 
we know of no clear evidence that toothed whales have abandoned 
significant parts of their range because of vessel traffic.
    Behavioral responses to stimuli are complex and influenced to 
varying degrees by a number of factors, such as species, behavioral 
contexts, geographical regions, source characteristics (moving or 
stationary, speed, direction, etc.), prior experience of the animal and 
physical status of the animal. For example, studies have shown that 
beluga whales' reactions varied when exposed to vessel noise and 
traffic. In some cases, naive beluga whales exhibited rapid swimming 
from ice-breaking vessels up to 80 km (49.7 mi) away, and showed 
changes in surfacing, breathing, diving, and group composition in the 
Canadian high Arctic where vessel traffic is rare (Finley et al., 
1990). In other cases, beluga whales were more tolerant of vessels, but 
responded differentially to certain vessels and operating 
characteristics by reducing their calling rates (especially older 
animals) in the St. Lawrence River where vessel traffic is common 
(Blane and Jaakson, 1994). In Bristol Bay, Alaska, beluga whales 
continued to feed when surrounded by fishing vessels and resisted 
dispersal even when purposefully harassed (Fish and Vania, 1971).
    In reviewing more than 25 years of whale observation data, Watkins 
(1986) concluded that whale reactions to vessel traffic were ``modified 
by their previous experience and current activity: Habituation often 
occurred rapidly, attention to other stimuli or preoccupation with 
other activities sometimes overcame their interest or wariness of 
stimuli.'' Watkins noticed that over the years of exposure to ships in 
the Cape Cod area, minke whales changed from frequent positive interest 
(e.g., approaching vessels) to generally uninterested reactions; fin 
whales changed from mostly negative (e.g.,

[[Page 51007]]

avoidance) to uninterested reactions; right whales apparently continued 
the same variety of responses (negative, uninterested, and positive 
responses) with little change; and humpbacks dramatically changed from 
mixed responses that were often negative to reactions that were often 
strongly positive. Watkins (1986) summarized that ``whales near shore, 
even in regions with low vessel traffic, generally have become less 
wary of boats and their noises, and they have appeared to be less 
easily disturbed than previously. In particular locations with intense 
shipping and repeated approaches by boats (such as the whale-watching 
areas of Stellwagen Bank), more and more whales had positive reactions 
to familiar vessels, and they also occasionally approached other boats 
and yachts in the same ways.''

Vessel Strike

    Ship strikes of cetaceans can cause major wounds, which may lead to 
the death of the animal. An animal at the surface could be struck 
directly by a vessel, a surfacing animal could hit the bottom of a 
vessel, or a vessel's propeller could injure an animal just below the 
surface. The severity of injuries typically depends on the size and 
speed of the vessel (Knowlton and Kraus, 2001; Laist et al., 2001; 
Vanderlaan and Taggart, 2007).
    The most vulnerable marine mammals are those that spend extended 
periods of time at the surface in order to restore oxygen levels within 
their tissues after deep dives (e.g., the sperm whale). In addition, 
some baleen whales, such as the North Atlantic right whale, seem 
generally unresponsive to vessel sound, making them more susceptible to 
vessel collisions (Nowacek et al., 2004). These species are primarily 
large, slow moving whales. Smaller marine mammals (e.g., bottlenose 
dolphin) move quickly through the water column and are often seen 
riding the bow wave of large ships. Marine mammal responses to vessels 
may include avoidance and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records with known vessel speeds, Laist et al. 
(2001) found a direct relationship between the occurrence of a whale 
strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 24.1 km/h (14.9 mph; 13 kts). Given the slow vessel speeds 
necessary for data acquisition, ship strike is unlikely to occur during 
this survey.

Entanglement

    Entanglement can occur if wildlife becomes immobilized in survey 
lines, cables, nets, or other equipment that is moving through the 
water column. The proposed survey would require towing approximately 
150 ft of cables. This size of the array generally carries a lower risk 
of entanglement for marine mammals. Wildlife, especially slow moving 
individuals, such as large whales, have a low probability of 
entanglement due to the low amount of slack in the lines, slow speed of 
the survey vessel, and onboard monitoring. Pinnipeds and porpoises are 
the least likely to entangle in equipment, as most documented cases of 
entanglement involve fishing gear and prey species (Gales et al., 
2003). There are no reported cases of entanglement from geophysical 
equipment in the Cook Inlet area.

Anticipated Effects on Marine Mammal Habitat

    The G&G Program survey areas are primarily within upper Cook Inlet, 
although the Marine Terminal survey area is located near Nikiski just 
south of the East Foreland (technically in Lower Cook Inlet), which 
includes habitat for prey species of marine mammals, including fish as 
well as invertebrates eaten by Cook Inlet beluga whales. This area 
contains Critical Habitat for Cook Inlet belugas, is near the breeding 
grounds for the local harbor seal population, and serves as an 
occasional feeding ground for killer whales and harbor porpoises. Cook 
Inlet is a large subarctic estuary roughly 299 km (186 mi) in length 
and averaging 96 km (60 mi) in width. It extends from the city of 
Anchorage at its northern end and flows into the Gulf of Alaska at its 
southernmost end. For descriptive purposes, Cook Inlet is separated 
into unique upper and lower sections, divided at the East and West 
Forelands, where the opposing peninsulas create a natural waistline in 
the length of the waterway, measuring approximately 16 km (10 mi) 
across (Mulherin et al. 2001).
    Potential effects on beluga habitat would be limited to noise 
effects on prey; direct impact to benthic habitat from jack-up platform 
leg placement, and sampling with grabs, coring, and boring; and small 
discharges of drill cuttings and drilling mud associated with the 
borings. Portions of the survey areas include waters of Cook Inlet that 
are <9.1 m (30 ft) in depth and within 8.0 km (5.0 mi) of anadromous 
streams. Several anadromous streams (Three-mile Creek, Indian Creek, 
and two unnamed streams) enter the Cook Inlet within the survey areas. 
Other anadromous streams are located within 8.0 km (5.0 mi) of the 
survey areas. The survey program will not prevent beluga access to the 
mouths of these streams and will result in no short-term or long-term 
loss of intertidal or subtidal waters that are <9.1 m (30 ft) in depth 
and within 8.0 km (5.0 mi) of anadromous streams. Minor seafloor 
impacts will occur in these areas from grab samples, PCPTs, vibracores, 
or geotechnical borings but will have no effect on the area as beluga 
habitat once the vessel or jack-up platform has left. The survey 
program will have no effect on this habitat.
    Cook Inlet beluga whales may avoid areas ensonified by the 
geophysical or geotechnical activities that generate sound with 
frequencies within the beluga hearing range and at levels above 
threshold values. This includes the chirp sub-bottom profiler with a 
radius of 184 m (604 ft), the boomer sub-bottom profiler with a radius 
of 263 m (863 ft), the airgun with a radius of 300 m (984 ft) and the 
vibracores with a radius of 2.54 km (1.58 mi). The sub-bottom profilers 
and the airgun will be operated from a vessel moving at speeds of about 
4 kt. The operation of a vibracore has a duration of approximately 1-2 
minutes. All of these activities will be conducted in relatively open 
areas of the Cook Inlet within Critical Habitat Area 2. Given the size 
and openness of the Cook Inlet in the survey areas, and the relatively 
small area and mobile/temporary nature of the zones of ensonification, 
the generation of sound by the G&G activities is not expected to result 
in any restriction of passage of belugas within or between critical 
habitat areas. The jack-up platform from which the geotechnical borings 
will be conducted will be attached to the seafloor with legs, and will 
be in place at a given location for up to 4-5 days, but given its small 
size (Table 4 in the application) would not result in any obstruction 
of passage by belugas.
    Upper Cook Inlet comprises the area between Point Campbell 
(Anchorage) down to the Forelands, and is roughly 95 km (59 mi) in 
length and 24.9 km (15.5 mi) in width (Mulherin et al. 2001). Five 
major rivers (Knik, Matanuska, Susitna, Little Susitna, and Beluga) 
deliver freshwater to upper Cook Inlet, carrying a heavy annual 
sediment load of over 40 million tons of eroded materials and glacial 
silt (Brabets 1999). As a result, upper Cook Inlet is

[[Page 51008]]

relatively shallow, averaging 18.3 m (60 ft) in depth. It is 
characterized by shoals, mudflats, and a wide coastal shelf, less than 
17.9 m (59 ft) deep, extending from the eastern shore. A deep trough 
exists between Trading Bay and the Middle Ground Shoal, ranging from 35 
to 77 m (114-253 ft) deep (NOAA Nautical Chart 16660). The substrate 
consists of a mixture of coarse gravels, cobbles, pebbles, sand, clay, 
and silt (Bouma et al. 1978, Rappeport 1982).
    Upper Cook Inlet experiences some of the most extreme tides in the 
world, demonstrated by a mean tidal range from 4.0 m (13 ft) at the 
Gulf of Alaska end to 8.8 m (29 ft) near Anchorage (U.S. Army Corps of 
Engineers 2013). Tidal currents reach 3.9 kts per second (Mulherin et 
al. 2001) in upper Cook Inlet, increasing to 5.7-7.7 kts per second 
near the Forelands where the inlet is constricted. Each tidal cycle 
creates significant turbulence and vertical mixing of the water column 
in the upper inlet (U.S. Army Corps of Engineers 2013), and are 
reversing, meaning that they are marked by a period of slack tide 
followed an acceleration in the opposite direction (Mulherin et al. 
2001).
    Because of scouring, mixing, and sediment transport from these 
currents, the marine invertebrate community is very limited (Pentec 
2005). Of the 50 stations sampled by Saupe et al. 2005 for marine 
invertebrates in Southcentral Alaska, their upper Cook Inlet station 
had by far the lowest abundance and diversity. Further, the fish 
community of upper Cook Inlet is characterized largely by migratory 
fish--eulachon and Pacific salmon--returning to spawning rivers, or 
outmigrating salmon smolts. Moulton (1997) documented only 18 fish 
species in upper Cook Inlet compared to at least 50 species found in 
lower Cook Inlet (Robards et al. 1999).
    Lower Cook Inlet extends from the Forelands southwest to the inlet 
mouth demarked by an approximate line between Cape Douglas and English 
Bay. Water circulation in lower Cook Inlet is dominated by the Alaska 
Coastal Current (ACC) that flows northward along the shores of the 
Kenai Peninsula until it turns westward and is mixed by the combined 
influences of freshwater input from upper Cook Inlet, wind, topography, 
tidal surges, and the coriolis effect (Field and Walker 2003, MMS 
1996). Upwelling by the ACC brings nutrient-rich waters to lower Cook 
Inlet and contributes to a biologically rich and productive ecology 
(Sambrotto and Lorenzen 1986). Tidal currents average 2-3 kt per second 
and are rotary in that they do not completely go slack before rotating 
around into an opposite direction (Gatto 1976, Mulherin et al. 2001). 
Depths in the central portion of lower Cook Inlet are 60-80 m (197-262 
ft) and decrease steadily toward the shores (Muench 1981). Bottom 
sediments in the lower inlet are coarse gravel and sand that grade to 
finer sand and mud toward the south (Bouma 1978).
    Coarser substrate support a wide variety of invertebrates and fish 
including Pacific halibut, Dungeness crab, tanner crab, pandalid 
shrimp, Pacific cod, and rock sole, while the soft-bottom sand and silt 
communities are dominated by polychaetes, bivalves and other flatfish 
(Field and Walker 2003). These species constitute prey species for 
several marine mammals in Cook Inlet, including pinnipeds and Cook 
Inlet belugas. Sea urchins and sea cucumbers are important otter prey 
and are found in shell debris communities. Razor clams are found all 
along the beaches of the Kenai Peninsula. In general, the lower Cook 
Inlet marine invertebrate community is of low abundance, dominated by 
polychaetes, until reaching the mouth of the inlet (Saupe et al. 2005). 
Overall, the lower Cook Inlet marine ecosystem is fed by midwater 
communities of phytoplankton and zooplankton, with the latter composed 
mostly of copepods and barnacle and crab larvae (Damkaer 1977, English 
1980).
    G&G Program activities that could potentially impact marine mammal 
habitats include sediment sampling (vibracore, boring, grab sampling) 
on the sea bottom, placement of the jack-up platform spud cans, and 
acoustical injury of prey resources. However, there are few benthic 
resources in the survey area that could be impacted by collection of 
the small samples (Saupe et al. 2005).
    Acoustical effects to marine mammal prey resources are also 
limited. Christian et al. (2004) studied seismic energy impacts on male 
snow crabs and found no significant increases in physiological stress 
due to exposure to high sound pressure levels. No acoustical impact 
studies have been conducted to date on the above fish species, but 
studies have been conducted on Atlantic cod and sardine. Davis et al. 
(1998) cited various studies that found no effects to Atlantic cod 
eggs, larvae, and fry when received levels were 222 dB. Effects found 
were to larval fish within about 5.0 m (16 ft), and from air guns with 
volumes between 49,661 and 65,548 cm3 (3,000 and 4,000 in\3\). 
Similarly, effects to sardine were greatest on eggs and 2-day larvae, 
but these effects were greatest at 0.5 m (1.6 ft), and again confined 
to 5.0 m (16 ft). Further, Greenlaw et al. (1988) found no evidence of 
gross histological damage to eggs and larvae of northern anchovy 
exposed to seismic air guns, and concluded that noticeable effects 
would result only from multiple, close exposures. Based on these 
results, much lower energy impulsive geophysical equipment planned for 
this program would not damage larval fish or any other marine mammal 
prey resource.
    Potential damage to the Cook Inlet benthic community will be 
limited to the actual surface area of the four spud cans that form the 
``foot'' of each 0.762-m (30-in) diameter leg, the 42 0.1524-m (6-in) 
diameter borings, and the 55 0.0762-m (3-in) diameter vibracore 
samplings (plus several grab and PCPT samples). Collectively, these 
samples would temporarily damage about a hundred square meters of 
benthic habitat relative to the size (nearly 21,000 km2/8,108 mi2) of 
Cook Inlet. Overall, sediment sampling and acoustical effects on prey 
resources will have a negligible effect at most on the marine mammal 
habitat within the G&G Program survey area. Some prey resources might 
be temporarily displaced, but no long-term effects are expected.
    The Cook Inlet 2015 G&G Program will result in a number of minor 
discharges to the waters of Cook Inlet. Discharges associated with the 
geotechnical borings will include: (1) The discharge of drill cuttings 
and drilling fluids and (2) the discharge of deck drainage (runoff of 
precipitation and deck wash water) from the geotechnical drilling 
platform. Other vessels associated with the G&G surveys will discharge 
wastewaters that are normally associated with the operation of vessels 
in transit including deck drainage, ballast water, bilge water, non-
contact cooling water, and gray water.
    The discharges of drill cuttings, drilling fluids, and deck 
drainage associated with the geotechnical borings will be within 
limitations authorized by the Alaska Department of Environmental 
Conservation under the Alaska Pollutant Discharge Elimination System. 
The drill cuttings consist of natural geologic materials of the 
seafloor sediments brought to the surface via the drill bit/drill stem 
of the rotary drilling operation, will be relatively minor in volume, 
and deposit over a very small area of Cook Inlet seafloor. The drilling 
fluids which are used to lubricate the bit, stabilize the hole, and 
viscosify the slurry for transport of the solids to the surface will 
consist of seawater and guar gum. Guar gum is a high-molecular weight 
polysaccharide (galactose and

[[Page 51009]]

mannose units) derived from the ground seeds of the plant Cyampsis 
gonolobus. It is a non-toxic fluid also used as a food additive in 
soups, drinks, breads, and meat products.
    Vessel discharges will be authorized under the U.S. Environmental 
Protection Agency's (EPA's) National Pollutant Discharge Elimination 
System (NPDES) Vessel General Permit (VGP) for Discharges Incidental to 
the Normal Operation of Vessels. Each vessel will have obtained 
authorization under the VGP and will discharge according to the 
conditions and limitations mandated by the permit. As required by 
statute and regulation, the EPA has made a determination that such 
discharges will not result in any unreasonable degradation of the 
marine environment, including:
     significant adverse changes in ecosystem diversity, 
productivity and stability of the biological community within the area 
of discharge and surrounding biological communities,
     threat to human health through direct exposure to 
pollutants or through consumption of exposed aquatic organisms, or
     loss of aesthetic, recreational, scientific or economic 
values which is unreasonable in relation to the benefit derived from 
the discharge.

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 (where relevant).
    To mitigate potential acoustical impacts to local marine mammals, 
Protected Species Observers (PSOs) will operate aboard the vessels from 
which the chirper, boomer, airgun, and vibracorer will be deployed. The 
PSOs will implement the mitigation measures described in the Marine 
Mammal Monitoring and Mitigation Plan (Appendix A of the application). 
These mitigations include: (1) Establishing safety zones to ensure 
marine mammals are not injured by sound pressure levels exceeding Level 
A injury thresholds; (2) shutting down the airgun when required to 
avoid harassment of beluga whales approaching the 160-dB disturbance 
zone; and (3) timing survey activity to avoid concentrations of beluga 
whales on a seasonal basis.
    Before chirper, boomer, airgun, and vibracoring operations begin 
each day and before restarting operations after a shutdown of 15 
minutes or greater, the PSOs will ``clear'' both the Level A and Level 
B Zones of Influence (ZOIs--area from the source to the 160dB or 180/
190dB isopleths) of marine mammals by intensively surveying these ZOIs 
prior to activity to confirm that marine mammals are not seen in the 
applicable area. All three geophysical activities (boomer, chirp, 
airgun) will be shut down in mid-operation at the approach to any 
marine mammal to the Level A safety zone, and at the approach of an 
ESA-listed beluga whale to the Level B harassment zone for these 
sources. The geotechnical vibracoring lasts only one or two minutes and 
shutdowns are likely impossible. Finally, the G&G Program will be 
planned to avoid high beluga whale density areas. This would be 
achieved by conducting surveys at the Marine Terminal and the southern 
end of the pipeline survey area when beluga whales are farther north, 
feeding near the Susitna Delta, and completing activities in the 
northern portion of the pipeline survey area when the Cook Inlet beluga 
whales have begun to disperse from the Susitna Delta and other summer 
concentration areas.

Vessel-Based Visual Mitigation Monitoring

    EMALL will hire qualified and NMFS-approved PSOs. These PSOs will 
be stationed aboard the geophysical survey source or support vessels 
during sub-bottom profiling, air gun, and vibracoring operations. A 
single senior PSO will be assigned to oversee all Marine Mammal 
Mitigation and Monitoring Program mandates and function as the on-site 
person-in-chargeimplementing the 4MP.
    Generally, two PSOs will work on a rotational basis during daylight 
hours with shifts of 4 to 6 hours, and one PSO on duty on each source 
vessel at all times. Work days for an individual PSO will not exceed 12 
hours in duration. Sufficient numbers of PSOs will be available and 
provided to meet requirements.
    Roles and responsibilities of all PSOs include the following:
     Accurately observe and record sensitive marine mammal 
species;
     Follow monitoring and data collection procedures; and
     Ensure mitigation measures are followed.
    PSOs will be stationed at the best available vantage point on the 
source vessels. PSOs will scan systematically with the unaided eye and 
7x50 reticle binoculars. As necessary, new PSOs will be paired with 
experienced PSOs to ensure that the quality of marine mammal 
observations and data recording are consistent.
    All field data collected will be entered by the end of the day into 
a custom database using a notebook computer. Weather data relative to 
viewing conditions will be collected hourly, on rotation, and when 
sightings occur and include the following:
     Sea state;
     Wind speed and direction;
     Sun position; and
     Percent glare.
    The following data will be collected for all marine mammal 
sightings:
     Bearing and distance to the sighting;
     Species identification;
     Behavior at the time of sighting (e.g., travel, spy-hop, 
breach, etc.);
     Direction and speed relative to vessel;
     Reaction to activities--changes in behavior (e.g., none, 
avoidance, approach, paralleling, etc.);
     Group size;
     Orientation when sighted (e.g., toward, away, parallel, 
etc.);
     Closest point of approach;
     Sighting cue (e.g., animal, splash, birds, etc.);
     Physical description of features that were observed or 
determined not to be present in the case of unknown or unidentified 
animals;
     Time of sighting;
     Location, speed, and activity of the source and mitigation 
vessels, sea state, ice cover, visibility, and sun glare; and positions 
of other vessel(s) in the vicinity, and
     Mitigation measure taken--if any.
    All observations and shut downs will be recorded in a standardized 
format and data entered into a custom database using a notebook 
computer. Accuracy of all data will be verified daily by the PIC or 
designated PSO by a manual verification. These procedures will reduce 
errors, allow the preparation of short-term data summaries, and 
facilitate transfer of the data to statistical, graphical, or other 
programs for further processing and archiving. PSOs will conduct 
monitoring during daylight periods (weather permitting) during G&G 
activities, and during most daylight periods when G&G activities are 
temporarily suspended.

Shutdown Procedures

    If any marine mammal is seen approaching the Level A injury zone 
for the air gun, chirp, or boomer, these sources will be shut down. If 
ESA-listed marine mammals (e.g., beluga whales) are observed 
approaching the Level B

[[Page 51010]]

harassment zone for the air gun, chirp, or boomer, these sources will 
be shut down. The PSOs will ensure that the harassment zone is clear of 
marine mammal activity before vibracoring will occur. Given that 
vibracoring lasts only about a minute or two, shutdown actions are not 
practicable.

Resuming Airgun Operations After a Shutdown

    A full ramp-up after a shutdown will not begin until there has been 
a minimum of 30 minutes of observation of the applicable exclusion zone 
by PSOs to assure that no marine mammals are present. The entire 
exclusion zone must be visible during the 30-minute lead-in to a full 
ramp up. If the entire exclusion zone is not visible, then ramp-up from 
a cold start cannot begin. If a marine mammal(s) is sighted within the 
injury exclusion 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 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), or 30 minutes for large odontocetes (e.g., killer whales 
and beluga whales).

Speed and Course Alterations

    If a marine mammal is detected outside the Level A injury exclusion 
zone and, based on its position and the relative motion, is likely to 
enter that zone, the vessel's speed and/or direct course may, when 
practical and safe, be changed to also minimize the effect on the 
survey program. The marine mammal activities and movements relative to 
the sound source and support vessels will be closely monitored to 
ensure that the marine mammal does not approach within the applicable 
exclusion radius. If the mammal appears likely to enter the exclusion 
radius, further mitigative actions will be taken, i.e., either further 
course alterations or shut down of the active sound sources considered 
in this Authorization.

Mitigation Required by NMFS

Special Procedures for Situations or Species of Concern

    The following additional protective measures for beluga whales and 
groups of five or more killer whales and harbor porpoises are required. 
Specifically, a 160-dB vessel monitoring zone would be established and 
monitored in Cook Inlet during all seismic surveys. If a beluga whale 
or groups of five or more killer whales and/or harbor porpoises are 
visually sighted approaching or within the 160-dB disturbance zone, 
survey activity would not commence until the animals are no longer 
present within the 160-dB disturbance zone. Whenever Cook Inlet beluga 
whales or groups of five or more killer whales and/or harbor porpoises 
are detected approaching or within the 160-dB disturbance zone, the 
boomer, chirp, and airgun may be powered down before the animal is 
within the 160-dB disturbance zone, as an alternative to a complete 
shutdown. If the PSO determines a power down is not sufficient, the 
sound source(s) shall be shut-down until the animals are no longer 
present within the 160-dB zone.

Mitigation Exclusion Zones

    NMFS requires that EMALL will not operate the chirp, boomer, 
vibracore, or airgun within 10 miles (16 km) of the mean lower low 
water (MLLW) line of the Susitna Delta (Beluga River to the Little 
Susitna River) between April 15 and October 15. The purpose of this 
mitigation measure is to protect beluga whales in the designated 
critical habitat in this area that is important for beluga whale 
feeding and calving during the spring and fall months. The range of the 
setback required by NMFS was designated to protect this important 
habitat area and also to create an effective buffer where sound does 
not encroach on this habitat. This seasonal exclusion will be in effect 
from April 15th to October 15th annually. Activities can occur within 
this area from October 16th-April 14th.

Mitigation Conclusions

    NMFS has carefully evaluated EMALL's mitigation measures in the 
context of ensuring that we prescribe 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.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed here:
     Avoidance or minimization of injury or death of marine 
mammals wherever possible (goals 2, 3, and 4 may contribute to this 
goal).
     A reduction in the numbers of marine mammals (total number 
or number at biologically important time or location) exposed to airgun 
operations that we expect to result in the take of marine mammals (this 
goal may contribute to 1, above, or to reducing harassment takes only).
     A reduction in the number of times (total number or number 
at biologically important time or location) individuals would be 
exposed to airgun operations that we expect to result in the take of 
marine mammals (this goal may contribute to 1, above, or to reducing 
harassment takes only).
     A reduction in the intensity of exposures (either total 
number or number at biologically important time or location) to airgun 
operations that we expect to result in the take of marine mammals (this 
goal may contribute to a, above, or to reducing the severity of 
harassment takes only).
     Avoidance or minimization of adverse effects to marine 
mammal habitat, paying special attention to the food base, activities 
that block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
     For monitoring directly related to mitigation--an increase 
in the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on the evaluation of EMALL's measures, as well as other 
measures required 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. Measures to ensure availability of such species or stock 
for taking for certain subsistence uses are discussed later in this 
document (see ``Impact on Availability of Affected Species or Stock for 
Taking for Subsistence Uses'' section).

Monitoring and Reporting

Weekly Field Reports

    Weekly reports will be submitted to NMFS no later than the close of 
business (Alaska Time) each Thursday during the weeks when in-water G&G 
activities take place. The reports will cover information collected 
from Wednesday of the previous week through Tuesday of the current 
week.

[[Page 51011]]

The field reports will summarize species detected, in-water activity 
occurring at the time of the sighting, behavioral reactions to in-water 
activities, and the number of marine mammals exposed to harassment 
level noise.

Monthly Field Reports

    Monthly reports will be submitted to NMFS for all months during 
which in-water G&G activities take place. The reports will be submitted 
to NMFS no later than five business days after the end of the month. 
The monthly report will contain and summarize the following 
information:
     Dates, times, locations, heading, speed, weather, sea 
conditions (including Beaufort Sea state and wind force), and 
associated activities during the G&G Program and marine mammal 
sightings.
     Species, number, location, distance from the vessel, and 
behavior of any sighted marine mammals, as well as associated G&G 
activity (number of shut downs), observed throughout all monitoring 
activities.
     An estimate of the number (by species) of: (i) Pinnipeds 
that have been exposed to the authorized geophysical or geotechnical 
activity (based on visual observation) at received levels greater than 
or equal to 160 dB re 1 [micro]Pa (rms) and/or 190 dB re 1 [micro]Pa 
(rms) with a discussion of any specific behaviors those individuals 
exhibited; and (ii) cetaceans that have been exposed to the geophysical 
activity (based on visual observation) at received levels greater than 
or equal to 160 dB re 1 [micro]Pa (rms) and/or 180 dB re 1 [micro]Pa 
(rms) with a discussion of any specific behaviors those individuals 
exhibited.
     An estimate of the number (by species) of pinnipeds and 
cetaceans that have been exposed to the geotechnical activity (based on 
visual observation) at received levels greater than or equal to 120 dB 
re 1 [micro]Pa (rms) with a discussion of any specific behaviors those 
individuals exhibited.
     A description of the implementation and effectiveness of 
the: (i) Terms and conditions of the Biological Opinion's Incidental 
Take Statement; and (ii) mitigation measures of the IHA. For the 
Biological Opinion, the report shall confirm the implementation of each 
Term and Condition, as well as any conservation recommendations, and 
describe their effectiveness, for minimizing the adverse effects of the 
action on ESA-listed marine mammals.

90-Day Technical Report

    A report will be submitted to NMFS within 90 days after the end of 
the project or at least 60 days before the request for another IHA for 
the next open water season to enable NMFS to incorporate observation 
data into the next Authorization. The report will summarize all 
activities and monitoring results (i.e., vessel-based visual 
monitoring) conducted during in-water G&G surveys. The Technical Report 
will include the following:
     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).
     Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare).
     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.
     Analyses of the effects of survey operations.
     Sighting rates of marine mammals during periods with and 
without G&G survey activities (and other variables that could affect 
detectability), such as: (i) Initial sighting distances versus survey 
activity state; (ii) closest point of approach versus survey activity 
state; (iii) observed behaviors and types of movements versus survey 
activity state; (iv) numbers of sightings/individuals seen versus 
survey activity state; (v) distribution around the source vessels 
versus survey activity state; and (vi) estimates of Level B harassment 
based on presence in the 120 or 160 dB harassment zone.

Notification of Injured or Dead Marine Mammals

    In the unanticipated event that the specified activity leads to an 
injury of a marine mammal (Level A harassment) or mortality (e.g., 
ship-strike, gear interaction, and/or entanglement), EMALL would 
immediately cease the specified activities and immediately report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, and the Alaska Regional Stranding Coordinators 
at NMFS. The report would 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 would not resume until NMFS is able to review the 
circumstances of the event. EMALL would work with NMFS to minimize 
reoccurrence of such an event in the future. The G&G Program would not 
resume activities until formally notified by NMFS via letter, email, or 
telephone.
    In the event that the G&G Program 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), the Applicant would 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 would include 
the same information identified in the paragraph above. Activities 
would be able to continue while NMFS reviews the circumstances of the 
incident. NMFS would work with the Applicant to determine if 
modifications in the activities are appropriate.
    In the event that the G&G Program 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), EMALL would 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, within 24 hours of the 
discovery. EMALL would provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network.

[[Page 51012]]

Estimated Take by Incidental Harassment

    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].
    Acoustic stimuli (i.e., increased underwater sound) generated 
during the operation of the airgun or the sub-bottom profiler have the 
potential to result in the behavioral disturbance of some marine 
mammals. NMFS believes that take from the operation of the vibracore is 
unlikely but possible and is issuing take at the request of the 
applicant. Thus, NMFS proposes to authorize take by Level B harassment 
resulting from the operation of the sound sources for the proposed 
survey based upon the current acoustic exposure criteria shown in Table 
3.

            Table 3--NMFS' Current Acoustic Exposure Criteria
------------------------------------------------------------------------
                                       Criterion
            Criterion                 definition           Threshold
------------------------------------------------------------------------
Level A Harassment (Injury).....  Permanent           180 dB re 1
                                   Threshold Shift     microPa-m
                                   (PTS) (Any level    (cetaceans)/190
                                   above that which    dB re 1 microPa-m
                                   is known to cause   (pinnipeds) root
                                   TTS).               mean square (rms)
Level B Harassment..............  Behavioral          160 dB re 1
                                   Disruption (for     microPa-m (rms)
                                   impulse noises)     120 dB re 1
                                   Behavioral          microPa-m (rms)
                                   Disruption (for
                                   continuous
                                   noises).
------------------------------------------------------------------------

    NMFS' practice is to apply the 120 or 160 dB re: 1 [micro]Pa 
received level threshold (whichever is appropriate) for underwater 
impulse sound levels to determine whether take by Level B harassment 
occurs.
    All four types of survey equipment addressed in the application 
will be operated from the geophysical source vessels that will either 
be moving steadily across the ocean surface (chirper, boomer, airgun), 
or from station to station (vibracoring). The numbers of marine mammals 
that might be exposed to sound pressure levels exceeding NMFS Level B 
harassment threshold levels due to G&G surveys, without mitigation, 
were determined by multiplying the average raw density for each species 
by the daily ensonified area, and then multiplying that figure by the 
number of days each sound source is estimated to be in use. The chirp 
and boomer activities were combined into one calculation because they 
will be operating concurrently, using the daily ensonified area of the 
boomer, as it is a slightly larger isopleth. The exposure estimates for 
each activity were then summed to provide total exposures for the 
duration of the project. The exposure estimates for the activity are 
detailed below. Although NMFS believes that take of marine mammals from 
vibracore is extremely unlikely, it has been included in this 
authorization out of an abundance of caution and at the request of the 
applicant.

Ensonified Area

    The ZOI is the area ensonified by a particular sound source greater 
than threshold levels (120 dB for continuous and 160 dB for impulsive). 
The radius of the ZOI for a particular equipment was determined by 
applying the source sound pressure levels described in Table 6 of the 
application to Collins et al.'s (2007) attenuation model of 18.4 
Log(r)-0.00188 derived from Cook Inlet. For those equipment generating 
loud underwater sound within the audible hearing range of marine 
mammals (<200 kHz), the distance to threshold ranges between 184 m (604 
ft) and 2.54 km (1.58 mi), with ZOIs ranging between 0.106 and 20.26 
km2 (0.041-7.82 mi2) (Table 4).

                    Table 4--Summary of Distances to the NMFS Thresholds and Associated ZOIs
----------------------------------------------------------------------------------------------------------------
                                                    Distance to     Distance to
                                                      160 dB          120 dB        160 dB ZOI      120 dB ZOI
                Survey equipment                  isopleth \1\ m   isopleth \1\   km\2\  (mi\2\)  km\2\  (mi\2\)
                                                        (ft)         km  (mi)
----------------------------------------------------------------------------------------------------------------
Sub-bottom Profiler (Chirp).....................       184 (604)             N/A   0.106 (0.041)             N/A
Sub-bottom Profiler (Boomer)....................       263 (863)             N/A   0.217 (0.084)             N/A
Airgun..........................................       300 (984)             N/A   0.283 (0.109)             N/A
Vibracore.......................................             N/A     2.54 (1.58)             N/A    20.26 (7.82)
----------------------------------------------------------------------------------------------------------------
\1\ Calculated by applying Collins et al. (2007) spreading formula to source levels in Table 2.

Marine Mammal Densities

    Density estimates were derived for harbor porpoises, killer whales, 
and harbor seals from NMFS 2002-2012 Cook Inlet survey data as 
described below in Section 6.1.2.1 and shown in Table 8. The beluga 
whale exposure estimates were calculated using density estimates from 
Goetz et al. (2012) as described in Section 6.1.2.2.

Harbor Porpoise, Killer Whale, Harbor Seal

    Density estimates were calculated for all marine mammals (except 
beluga whales) by using aerial survey data collected by NMFS in Cook 
Inlet between 2002 and 2012 (Rugh et al. 2002, 2003, 2004a, 2004b, 
2005a, 2005b, 2005c, 2006, 2007; Shelden et al. 2008, 2009, 2010; Hobbs 
et al. 2011, Shelden et al. 2012) and compiled by Apache, Inc. (Apache 
IHA application 2014). To estimate the average raw densities of marine 
mammals, the total number of animals for each species observed over the 
11-year survey period was divided by the total area of 65,889 km\2\ 
(25,540 mi\2\) surveyed over the 11 years. The aerial survey marine 
mammal sightings, survey effort (area), and derived average raw 
densities are provided in Table 5.

[[Page 51013]]



            Table 5--Raw Density Estimates for Cook Inlet Marine Mammals Based on NMFS Aerial Surveys
----------------------------------------------------------------------------------------------------------------
                                                                                                Mean raw density
                        Species                              Number of       NMFS survey area    animals/km \2\
                                                              animals        km \2\  (mi \2\)   (animals/mi \2\)
----------------------------------------------------------------------------------------------------------------
Harbor Porpoise........................................                249    65,889 (25,440)    0.0033 (0.0098)
Killer Whale \1\.......................................                 42    65,889 (25,440)    0.0008 (0.0017)
Harbor Seal............................................             16,117    65,889 (25,440)      0.28 (0.6335)
----------------------------------------------------------------------------------------------------------------
\1\ Density is for all killer whales regardless of the stock although all killer whales in the upper Cook Inlet
  are thought to be transient.

    These raw densities were not corrected for animals missed during 
the aerial surveys as no accurate correction factors are currently 
available for these species; however, observer error may be limited as 
the NMFS surveyors often circled marine mammal groups to get an 
accurate count of group size. The harbor seal densities are probably 
biased upwards given that a large number of the animals recorded were 
of large groups hauled out at river mouths, and do not represent the 
distribution in the waters where the G&G activity will actually occur. 
However, these data are the most comprehensive available for Cook Inlet 
harbor seals and therefore constitute the best available science.

Beluga Whale

    Goetz et al. (2012) modeled aerial survey data collected by the 
NMFS between 1993 and 2008 and developed specific beluga summer 
densities for each 1-km2 cell of Cook Inlet. The results provide a more 
precise estimate of beluga density at a given location than simply 
multiplying all aerial observations by the total survey effort given 
the clumped distribution of beluga whales during the summer months. To 
develop a density estimate associated with planned action areas (i.e., 
Marine Terminal and pipeline survey areas), the ensonified area 
associated with each activity was overlain a map of the 1-km density 
cells, the cells falling within each ensonified area were quantified, 
and an average cell density was calculated. The summary of the density 
results is found in Table 9 in the application. The associated 
ensonified areas and beluga density contours relative to the action 
areas are shown in Table 6.

  Table 6--Mean Raw Densities of Beluga Whales Within the Action Areas Based on Goetz et al. (2012) Cook Inlet
                                       Beluga Whale Distribution Modeling
----------------------------------------------------------------------------------------------------------------
                                                                             Mean density        Density range
                     Action area                        Number of cells     (animals/km\2\)     (animals/km\2\)
----------------------------------------------------------------------------------------------------------------
Marine Terminal Survey Area.........................                 386            0.000166   0.000021-0.001512
Pipeline Survey Area................................                 571            0.011552   0.000275-0.156718
----------------------------------------------------------------------------------------------------------------

Activity Duration

    The Cook Inlet 2015 G&G Program is expected to require 
approximately 12 weeks (84 days) to complete. During approximately 63 
of these days, the chirp and boomer sub-bottom profiler will produce 
the loudest sound levels. Airgun use will occur during approximately 7 
days and will occur only near the proposed Marine Terminal. The airgun 
activity will occur during the summer when beluga whale use of Cook 
Inlet is primarily concentrated near the Susitna Delta, approximately 
65 km (40 mi) north of the airgun survey area. Vibracoring, with its 
large ZOI, will occur intermittently over approximately 14 days. The 
applicant provided an estimate of 50 miles per day that the survey 
vessel could travel.

Exposure Calculations

    The numbers of marine mammals that might be exposed to sound 
pressure levels exceeding NMFS Level B harassment threshold levels due 
to G&G surveys, without mitigation, were determined by multiplying the 
average raw density for each species by the daily ensonified area, then 
multiplying by the number of days each sound source is estimated to be 
in use. While this method produces a good estimate of the number of 
instances of take, it is likely an overestimate of the number of 
individual marine mammals taken because it assumes that entirely new 
individuals are taken on subsequent days and that no animals are taken 
more than once. The chirp and boomer activities were combined to 
calculate exposure from days of activities in the Upper Cook Inlet area 
and the Lower Cook Inlet area because they will be operating 
concurrently. The exposure estimates for each activity were then summed 
to provide total exposures for the duration of the project. The 
exposure estimates for the activity are detailed below.

                                                        Table 7--Exposure Estimates for Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
           Species                 Density     Boomer--Upper  Boomer--Lower     Airgun    Vibracore--Upper  Vibracore--Lower     Total     Authorization
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga.......................   0.0012 .00017         18.18           0.18         0.056            5.15              0.11          23.69             24
Killer whale.................         0.00082          1.29           0.91          0.28            0.37              0.55           3.39              5
Harbor seal..................            0.28        444.52         312.37         95.99          125.92            188.89       1,167.68          1,168
Harbor porpoise..............          0.0033          5.18           3.64          1.12            1.47              2.20          13.60             20
--------------------------------------------------------------------------------------------------------------------------------------------------------

    NMFS recognizes that in addition to what was mentioned above, there 
are other factors that contribute to an overestimate of exposures,, 
e.g., the fact that many of these technologies will be operating 
simultaneously, and not

[[Page 51014]]

exposing animals in separate instances for the duration of the survey 
period. Additionally, the beamwidth and tilt angle of the sub-bottom 
profiler are not factored into the characterization of the sound field, 
making it conservative and large, creating additional overestimates in 
take estimation.
    The possibility of Level A exposure was analyzed, however the 
distances to 180 dB/190 dB isopleths are incredibly small, ranging from 
0 to 26 meters. The number of exposures, without accounting for 
mitigation or likely avoidance of louder sounds, is small for these 
zones, and with mitigation and the likelihood of detecting marine 
mammals within this small area combined with the likelihood of 
avoidance, it is likely these takes can be avoided. The only technology 
that would not shutdown is the vibracore, which has a distance to Level 
A isopleth (180 dB) of 3 meters. Therefore, authorization of Level A 
take is not necessary.
    NMFS will authorize the following takes by Level B harassment:

                                                                 Table 8--Authorizations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Exposure          Take
                Species                     estimate       authorized         Percent of stock or population                 Population trend
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga.................................           23.69              24  7.06...................................  Decreasing.
Killer whale...........................            3.39               5  1.44 transient.........................  Transient--Stable.
Harbor seal............................        1,167.68           1,168  5.10...................................  Stable.
Harbor porpoise........................           13.60              20  0.064..................................  No reliable info.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Analysis and Determinations

Negligible Impact

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). The lack of 
likely adverse effects on annual rates of recruitment or survival 
(i.e., population level effects) forms the basis of a negligible impact 
finding. Thus, an estimate of the number of takes, alone, is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through behavioral harassment, NMFS must consider other 
factors, such as the likely nature of any responses (their intensity, 
duration, etc.), the context of any responses (critical reproductive 
time or location, migration, etc.), as well as the number and nature of 
estimated Level A harassment takes, the number of estimated 
mortalities, effects on habitat, and the status of the species.
    To avoid repetition, except where otherwise identified, the 
discussion of our analyses applies to all the species listed in Table 
8, given that the anticipated effects of this project on marine mammals 
are expected to be relatively similar in nature. Where there is 
information about specific impacts to, or about the size, status, or 
structure of, any species or stock that would lead to a different 
analysis for this activity, species-specific factors are identified and 
analyzed.
    In making a negligible impact determination, NMFS considers:
     The number of anticipated injuries, serious injuries, or 
mortalities;
     The number, nature, and intensity, and duration of Level B 
harassment; and
     The context in which the takes occur (e.g., impacts to 
areas of significance, impacts to local populations, and cumulative 
impacts when taking into account successive/contemporaneous actions 
when added to baseline data);
     The status of stock or species of marine mammals (i.e., 
depleted, not depleted, decreasing, increasing, stable, impact relative 
to the size of the population);
     Impacts on habitat affecting rates of recruitment/
survival; and
     The effectiveness of monitoring and mitigation measures to 
reduce the number or severity of incidental take.
    As discussed in the Potential Effects section, temporary or 
permanent threshold shift, non-auditory physical or physiological 
effects, ship strike, entanglement are not expected to occur. Given the 
required mitigation and related monitoring, no injuries or mortalities 
are anticipated to occur to any species as a result of EMALL's proposed 
survey in Cook Inlet, and none are authorized. Animals in the area are 
not expected to incur hearing impairment (i.e., TTS or PTS) or non-
auditory physiological effects due to low source levels and the fact 
that most marine mammals would more likely avoid a loud sound source 
rather than swim in such close proximity as to result in TTS or PTS. 
The most likely effect from the proposed action is localized, short-
term behavioral disturbance from active acoustic sources. The number of 
takes that are anticipated and authorized are expected to be limited to 
short-term Level B behavioral harassment for all stocks for which take 
is authorized. This is largely due to the short time scale of the 
proposed activity, the low source levels for many of the technologies 
proposed to be used, as well as the required mitigation. The 
technologies do not operate continuously over a 24-hour period. Rather, 
airguns are operational for a few hours at a time for 7 days, with the 
sub-bottom profiler chirp and boomer operating for 63 days, and the 
vibracore operating over 14 days.
    The addition of five vessels, and noise due to vessel operations 
associated with the survey, would not be outside the present experience 
of marine mammals in Cook Inlet, although levels may increase locally. 
Potential impacts to marine mammal habitat were discussed previously in 
this document (see the ``Anticipated Effects on Habitat'' section). 
Although some disturbance is possible to food sources of marine 
mammals, the impacts are anticipated to be minor enough as to not 
affect annual rates of recruitment or survival of marine mammals in the 
area. 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.
    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.'' Shut-downs are required for belugas and groups of killer 
whales or harbor porpoises when they approach the 160dB disturbance 
zone, to further reduce potential impacts to these populations. Visual 
observation by trained PSOs is also implemented to reduce the impact of 
the proposed

[[Page 51015]]

activity by informing operators of marine mammals approaching the 
relevant disturbance or injury zones. Animals are not expected to 
permanently abandon any area that is surveyed, and any behaviors that 
are interrupted during the activity are expected to resume once the 
activity ceases. Only a small portion of marine mammal habitat will be 
affected at any time, and other areas within Cook Inlet will be 
available for necessary biological functions.
    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. This 
information supports the idea that the numerated takes for odonotocetes 
are likely on the lower end of severity in the terms of responses that 
rise to the level of a take.

Beluga Whales

    Cook Inlet beluga whales are listed as endangered under the ESA. 
This stock is also considered depleted under the MMPA. The estimated 
annual rate of decline for Cook Inlet beluga whales was 0.6 percent 
between 2002 and 2012. The authorization of take by Level B harassment 
of 24 Cook Inlet beluga whales represents 7.06 percent of the 
population.
    Belugas in the Canadian Beaufort Sea in summer appear to be fairly 
responsive to seismic energy, with few being sighted within 10-20 km 
(6-12 mi) of seismic vessels during aerial surveys (Miller et al., 
2005). However, as noted above, Cook Inlet belugas are more accustomed 
to anthropogenic sound than beluga whales in the Beaufort Sea. 
Therefore, the results from the Beaufort Sea surveys do not directly 
translate to potential reactions of Cook Inlet beluga whales. Also, due 
to the dispersed distribution of beluga whales in Cook Inlet during 
winter and the concentration of beluga whales in upper Cook Inlet from 
late April through early fall, belugas would likely occur in small 
numbers in the majority of EMALL's proposed survey area during the 
majority of EMALL's annual operational timeframe of August through 
December. For the same reason, as well as the mitigation measure that 
requires shutting down for belugas seen approaching the 160dB 
disturbance zone, and the likelihood of avoidance at high levels, it is 
unlikely that animals would be exposed to received levels capable of 
causing injury.
    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 from the two source 
vessels, tug and jack-up rig and associated vessel noise is not 
expected to have effects that could cause significant or long-term 
consequences for individual marine mammals or their populations, given 
that vessels will operate for a maximum of 84 days.
    In addition, NMFS has seasonally restricted survey operations in 
the area known to be important for beluga whale feeding, calving, or 
nursing. The primary location for these biological life functions 
occurs in the Susitna Delta region of upper Cook Inlet. NMFS required 
EMALL to implement a 16 km (10 mi) seasonal exclusion from survey 
operations in this region from April 15-October 15. The highest 
concentrations of belugas are typically found in this area from early 
May through September each year. NMFS has incorporated a 2-week buffer 
on each end of this seasonal use timeframe to account for any anomalies 
in distribution and marine mammal usage.

Killer Whales

    The authorization of take by Level B harassment of 5 killer whales 
represents only 1.44 percent of the population. Killer whales are not 
encountered as frequently in Cook Inlet as some of the other species in 
this analysis, however when sighted they are usually in groups. The 
addition of a mitigation measure to shutdown if a group of 5 or more 
killer whales is seen approaching the 160 dB zone is intended to 
minimize any impact to an aggregation of killer whales if encountered. 
The killer whales in the survey area are also thought to be transient 
killer whales and therefore rely on the habitat in the EMALL survey 
area less than other resident species.

Harbor Porpoise

    The authorization of take by Level B harassment for 20 harbor 
porpoises represents only 0.064 percent of the population. Harbor 
porpoises are among the most sensitive marine mammal species with 
regard to behavioral response and anthropogenic noise. They are known 
to exhibit behavioral responses to operation of seismic airguns, 
pingers, and other technologies at low thresholds. However, they are 
abundant in Cook Inlet and therefore the authorized take is unlikely to 
affect recruitment or status of the population in any way. In addition, 
mitigation measures include shutdowns for groups of more than 5 harbor 
porpoises that will minimize the amount of take to the local harbor 
porpoise population. This mitigation as well as the short duration and 
low source levels of the proposed activity will reduce the impact to 
the harbor porpoises found in Cook Inlet.

Harbor Seal

    The authorization of take by Level B harassment for 1,168 harbor 
seals represents only 5.1% of a stable population. Observations during 
other anthropogenic activities in Cook Inlet have reported large 
congregations of harbor seals hauling out in upper Cook Inlet. However, 
mitigation measures, such as vessel speed, course alteration, and 
visual monitoring, and time-area restrictions will be implemented to 
help reduce impacts to the animals. Additionally, this activity does 
not encompass a large number of known harbor seal haulouts, 
particularly as this activity proposes operations traversing across the 
Inlet, as opposed to entirely nearshore activities. While some harbor 
seals will likely be exposed, the required mitigation along with their 
smaller aggregations in water than on shore should minimize impacts to 
the harbor seal population. Additionally, the short duration of the 
survey, and the use of visual observers to inform shutdowns and ramp up 
delays should further reduce the severity of behavioral reactions to 
Cook Inlet harbor seals. Therefore, the exposure of pinnipeds to sounds 
produced by this phase of EMALL's proposed survey is not anticipated to 
have an effect on annual rates of recruitment or survival on those 
species or stocks.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the required monitoring and 
mitigation measures, NMFS finds that the total annual marine mammal 
take from EMALL's proposed survey will have a negligible impact on the 
affected marine mammal species or stocks (see Table 8).
    Although NMFS believes it is unlikely the operation of the 
vibracore would result in the take of marine mammals and did not 
propose to authorize take by vibracore in the Federal Register notice 
of the proposed Authorization, we note here that take from vibracoring 
activities has been included in the Final Authorization out of an 
abundance of caution and at the request of the applicant. Take by Level 
B harassment from vibracoring accounts for approximately 25 percent of 
the take authorized for the entire survey, ranging from 0.9 killer 
whales to 313 harbor seals. The vibracoring activity is

[[Page 51016]]

proposed to occur at 55 locations across the Inlet from the Forelands, 
north to the upper end of Cook Inlet. However, the actual noise-
producing activity will only occur for only 90 seconds at a time, 
during which PSOs will be observing for marine mammals. The limited 
scope and duration of vibracoring makes it extremely unlikely that take 
by Level B harassment would occur during the vibracore portion of the 
operation. Nonetheless, we included the potential take from vibracore 
in our analysis above, and as we indicated, we found that there would 
be a negligible impact on the affect species or stocks from the total 
takes, including any that are authorized for vibracore.

Small Numbers Analysis

    The requested takes authorized annually represent 7.06 percent of 
the Cook Inlet beluga whale population of approximately 340 animals 
(Allen and Angliss, 2014), 1.44 percent of the Gulf of Alaska, Aleutian 
Island and Bering Sea stock of killer whales (345 transients), and 
0.064 percent of the Gulf of Alaska stock of approximately 31,046 
harbor porpoises. The take requests presented for harbor seals 
represent 5.02 percent of the Cook Inlet/Shelikof stock of 
approximately 22,900 animals. These take estimates represent small 
numbers relative to the affected species or stock sizes as shown in 
Table 8.
    In addition to the quantitative methods used to estimate take, NMFS 
also considered qualitative factors that further support the ``small 
numbers'' determination, including: (1) The seasonal distribution and 
habitat use patterns of Cook Inlet beluga whales, which suggest that 
for much of the time only a small portion of the population would be 
accessible to impacts from EMALL's activity, as most animals are found 
in the Susitna Delta region of Upper Cook Inlet from early May through 
September; (2) other cetacean species are not common in the survey 
area; (3) the required mitigation requirements, which provide spatio-
temporal limitations that avoid impacts to large numbers of belugas 
feeding and calving in the Susitna Delta; (4) the required monitoring 
requirements and mitigation measures described earlier in this document 
for all marine mammal species that will reduce the amount of takes; and 
(5) monitoring results from previous activities that indicated low 
numbers of beluga whale sightings within the Level B disturbance 
exclusion zone and low levels of Level B harassment takes of other 
marine mammals. Therefore, NMFS determined that the numbers of animals 
likely to be taken are small.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

Relevant Subsistence Uses

    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).
    The Cook Inlet beluga whale has traditionally been hunted by Alaska 
Natives for subsistence purposes. For several decades prior to the 
1980s, the Native Village of Tyonek residents were the primary 
subsistence hunters of Cook Inlet beluga whales. During the 1980s and 
1990s, Alaska Natives from villages in the western, northwestern, and 
North Slope regions of Alaska either moved to or visited the south 
central region and participated in the yearly subsistence harvest 
(Stanek, 1994). From 1994 to 1998, NMFS estimated 65 whales per year 
(range 21-123) were taken in this harvest, including those successfully 
taken for food and those struck and lost. NMFS concluded that this 
number was high enough to account for the estimated 14 percent annual 
decline in the population during this time (Hobbs et al., 2008). Actual 
mortality may have been higher, given the difficulty of estimating the 
number of whales struck and lost during the hunts. In 1999, a 
moratorium was enacted (Pub. L. 106-31) prohibiting the subsistence 
take of Cook Inlet beluga whales except through a cooperative agreement 
between NMFS and the affected Alaska Native organizations. Since the 
Cook Inlet beluga whale harvest was regulated in 1999 requiring 
cooperative agreements, five beluga whales have been struck and 
harvested. Those beluga whales were harvested in 2001 (one animal), 
2002 (one animal), 2003 (one animal), and 2005 (two animals). The 
Native Village of Tyonek agreed not to hunt or request a hunt in 2007, 
when no co-management agreement was to be signed (NMFS, 2008a).
    On October 15, 2008, NMFS published a final rule that established 
long-term harvest limits on 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 interval period if the average stock 
abundance of Cook Inlet beluga whales over the prior five-year interval 
is below 350 whales. Harvest levels for the current 5-year planning 
interval (2013-2017) are zero because the average stock abundance for 
the previous five-year period (2008-2012) was below 350 whales. Based 
on the average abundance over the 2002-2007 period, no hunt occurred 
between 2008 and 2012 (NMFS, 2008a). The Cook Inlet Marine Mammal 
Council, which managed the Alaska Native Subsistence fishery with NMFS, 
was disbanded by a unanimous vote of the Tribes' representatives on 
June 20, 2012. At this time, no harvest is expected in 2015 or, likely, 
in 2016.
    Data on the harvest of other marine mammals in Cook Inlet are 
lacking. Some data are available on the subsistence harvest of harbor 
seals, harbor porpoises, and killer whales in Alaska in the marine 
mammal stock assessments. However, these numbers are for the Gulf of 
Alaska including Cook Inlet, and they are not indicative of the harvest 
in Cook Inlet.
    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. Some detailed 
information on the subsistence harvest of harbor seals is available 
from past studies conducted by the Alaska Department of Fish & Game 
(Wolfe et al., 2009). In 2008, 33 harbor seals were taken for harvest 
in the Upper Kenai-Cook Inlet area. In the same study, reports from 
hunters stated that harbor seal populations in the area were increasing 
(28.6%) or remaining stable (71.4%). The specific hunting regions 
identified were Anchorage, Homer, Kenai, and Tyonek, and hunting 
generally peaks in March, September, and November (Wolfe et al., 2009).

Potential Impacts on Availability for Subsistence Uses

    Section 101(a)(5)(D) also requires NMFS to determine that the 
taking 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

[[Page 51017]]

be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    The primary concern is the disturbance of marine mammals through 
the introduction of anthropogenic sound into the marine environment 
during the proposed survey. Marine mammals could be behaviorally 
harassed and either become more difficult to hunt or temporarily 
abandon traditional hunting grounds. However, the proposed survey will 
not have any impacts to beluga harvests as none currently occur in Cook 
Inlet. Additionally, subsistence harvests of other marine mammal 
species are limited in Cook Inlet.

Plan of Cooperation or Measures To Minimize Impacts to Subsistence 
Hunts

    The entire upper Cook unit and a portion of the lower Cook unit 
falls north of 60[deg] N., or within the region NMFS has designated as 
an Arctic subsistence use area. EMALL provided detailed information in 
Section 8 of their application regarding their plan to cooperate with 
local subsistence users and stakeholders regarding the potential 
effects of their proposed activity. There are several villages in 
EMALL's proposed project area that have traditionally hunted marine 
mammals, primarily harbor seals. Tyonek is the only tribal village in 
upper Cook Inlet with a tradition of hunting marine mammals, in this 
case harbor seals and beluga whales. However, for either species the 
annual recorded harvest since the 1980s has averaged about one or fewer 
of either species (Fall et al. 1984, Wolfe et al. 2009, SRBA and HC 
2011), and there is currently a moratorium on subsistence harvest of 
belugas. Further, many of the seals that are harvested are done 
incidentally to salmon fishing or moose hunting (Fall et al. 1984, 
Merrill and Orpheim 2013), often near the mouths of the Susitna Delta 
rivers (Fall et al. 1984) north of EMALL's proposed seismic survey 
area.
    Villages in lower Cook Inlet adjacent to EMALL's proposed survey 
area (Kenai, Salamatof, and Nikiski) have either not traditionally 
hunted beluga whales, or at least not in recent years, and rarely do 
they harvest sea lions. These villages more commonly harvest harbor 
seals, with Kenai reporting an average of about 13 per year between 
1992 and 2008 (Wolfe et al. 2009). According to Fall et al. (1984), 
many of the seals harvested by hunters from these villages were taken 
on the west side of the inlet during hunting excursions for moose and 
black bears.
    Although marine mammals remain an important subsistence resource in 
Cook Inlet, the number of animals annually harvested is low, and are 
primarily harbor seals. Much of the harbor seal harvest occurs 
incidental to other fishing and hunting activities, and at areas 
outside of the EMALL's proposed survey areas such as the Susitna Delta 
or the west side of lower Cook Inlet. Also, EMALL is unlikely to 
conduct activity in the vicinity of any of the river mouths where large 
numbers of seals haul out.
    EMALL and NMFS recognize the importance of ensuring that Alaska 
Natives and federally recognized tribes are informed, engaged, and 
involved during the permitting process and will continue to work with 
the Alaska Natives and tribes to discuss operations and activities.
    Prior to offshore activities EMALL was to consult with nearby 
communities such as Tyonek, Salamatof, and the Kenaitze Indian Tribe to 
attend and present the program description prior to operations within 
those areas. These meetings were conducted and no issues related to 
subsistence use of marine mammals was raised.
    If a conflict does occur with project activities involving 
subsistence or fishing, the project manager will immediately contact 
the affected party to resolve the conflict.

Unmitigable Adverse Impact Analysis and Determination

    The project will not have any effect on beluga whale harvests 
because no beluga harvest will take place in 2015. Additionally, the 
proposed seismic survey area is not an important native subsistence 
site for other subsistence species of marine mammals thus, the number 
harvested is expected to be extremely low. The timing and location of 
subsistence harvest of Cook Inlet harbor seals may coincide with 
EMALL's project, but because this subsistence hunt is conducted 
opportunistically and at such a low level (NMFS, 2013c), EMALL's 
program is not expected to have an impact on the subsistence use of 
harbor seals. Moreover, the proposed survey would result in only 
temporary disturbances. Accordingly, the specified activity would not 
impact the availability of these other marine mammal species for 
subsistence uses.
    NMFS anticipates that any effects from EMALL's proposed survey on 
marine mammals, especially harbor seals and 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. Based on the description of the specified activity, the 
measures described to minimize adverse effects on the availability of 
marine mammals for subsistence purposes, and the required mitigation 
and monitoring measures, NMFS has determined that there will not be an 
unmitigable adverse impact on subsistence uses from EMALL's proposed 
activities.

Endangered Species Act

    There is one marine mammal species listed as endangered under the 
ESA with confirmed or possible occurrence in the project area: The Cook 
Inlet beluga whale. In addition, the action could occur within 10 miles 
of designated critical habitat for the Cook Inlet beluga whale. NMFS's 
Permits and Conservation Division has initiated consultation with NMFS' 
Alaska Region Protected Resources Division under section 7 of the ESA. 
This consultation concluded on August 13, 2015, when a Biological 
Opinion was issued. The Biological Opinion determined that the issuance 
of an IHA is not likely to jeapordize the continued existence of the 
Cook Inlet beluga whales or destroy or adversely modify Cook Inlet 
beluga whale critical habitat. Finally, the Alaska region issued an 
Incidental Take Statement (ITS) for Cook Inlet beluga whales. The ITS 
contains reasonable and prudent measures implemented by the terms and 
conditions to minimize the effect of this take.

National Environmental Policy Act

    NMFS prepared an EA that includes an analysis of potential 
environmental effects associated with NMFS' issuance of an IHA to EMALL 
to take marine mammals incidental to conducting a geophysical and 
geotechnical survey program in Cook Inlet, Alaska. NMFS has finalized 
the EA and prepared a Finding of No Significant Impact for this action. 
Therefore, preparation of an Environmental Impact Statement is not 
necessary.

[[Page 51018]]

Authorization

    As a result of these determinations, NMFS has issued an IHA to 
Exxon Mobil Alaska LNG LLC (EMALL) for taking marine mammals incidental 
to a geophysical and geotechnical survey in Cook Inlet, Alaska, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: August 17, 2015.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2015-20605 Filed 8-20-15; 8:45 am]
 BILLING CODE 3510-22-P