Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Seismic Surveys in Cook Inlet, Alaska, 29161-29189 [2015-12091]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 97 (Wednesday, May 20, 2015)]
[Notices]
[Pages 29161-29189]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-12091]



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Vol. 80

Wednesday,

No. 97

May 20, 2015

Part II





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 Seismic Surveys in Cook Inlet, Alaska; 
Notices

Federal Register / Vol. 80 , No. 97 / Wednesday, May 20, 2015 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD830


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Seismic Surveys 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 Incidental Harassment Authorization in 
response to a request from SAExploration Inc. (SAE) for authorization 
to take marine mammals incidental to an oil and gas exploration seismic 
survey program in Cook Inlet, Alaska between May 13, 2015 and May 12, 
2016.

DATES: Effective: May 13, 2015 through May 12, 2016.

ADDRESSES: Electronic copies of the IHA, 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) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to 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 October 28, 2014, we received a request from SAE for 
authorization to take marine mammals incidental to seismic surveys in 
Cook Inlet, Alaska. After further correspondence and revisions by the 
applicant, we determined that the application was adequate and complete 
on January 12, 2015. On March 20, 2015, NMFS published a notice in the 
Federal Register of our proposal to issue an IHA with preliminary 
determinations (80 FR 14913). The filing of the notice initiated a 30-
day public comment period. The comments and our responses are discussed 
later in this document.
    SAE proposes to conduct oil and gas exploration seismic surveys. 
The activity will occur between May 13, 2015 and May 12, 2016, for a 
period of 160 days. The following specific aspects of the activity are 
likely to result in the take of marine mammals: Operation of seismic 
airguns in arrays of 440 in\3\ and 1,760 in\3\. Take, by Level B 
Harassment only, of individuals of beluga whale, humpback whale, minke 
whale, gray whale, harbor porpoise, Dall's porpoise, killer whale, 
harbor seal, and Steller sea lion is anticipated to result from the 
specified activity.

Description of the Specified Activity

Overview

    SAE plans to conduct 3D seismic surveys over multiple years in the 
marine waters of both upper and lower Cook Inlet. This authorization 
will cover activities occurring between May 13, 2015 and May 12, 2016. 
The ultimate survey area is divided into two units (upper and lower 
Cook Inlet). The total potential survey area is 3,934 square kilometers 
(1,519 square miles); however, only a portion (currently unspecified) 
of this area will ultimately be surveyed, and no more than 777 square 
kilometers (300 square miles) in a given year. The exact location of 
where the 2015 survey will be conducted is not known at this time, and 
probably will not be known until late spring 2015 when SAE's clients 
have finalized their data acquisition needs.
    The components of the project include laying recording sensors 
(nodes) on the ocean floor, operating seismic source vessels towing 
active air gun arrays, and retrieval of nodes. There will also be 
additional boat activity associated with crew transfer, recording 
support, and additional monitoring for marine mammals. The primary 
seismic source for offshore recording consists of a 2 x 880-cubic-inch 
tri-cluster array for a total of 1,760-cubic-inches (although a 440-
cubic-inch array may be used in very shallow water locations as 
necessary). Each of the arrays will be deployed in a configuration 
outlined in Appendix A of the application. The arrays will be centered 
approximately 15 meters (50 feet) behind the source vessel stern, at a 
depth of 4 meters (12 feet), and towed along predetermined source lines 
at speeds between 7.4 and 9.3 kilometers per hour (4 and 5 knots). Two 
vessels with full arrays will be operating simultaneously in an 
alternating shot mode; one vessel shooting while the other is 
recharging. Shot intervals are expected to be about 16 seconds for each 
array resulting in an overall shot interval of 8 seconds considering 
the two alternating arrays. Operations are expected to occur 24 hours a 
day, with actual daily shooting to total about 12 hours. An acoustical 
positioning (or pinger) system will be used to position and interpolate 
the location of the nodes. A vessel-mounted transceiver calculates the 
position of the nodes by measuring the range and bearing from the 
transceiver to a small acoustic transponder fitted to every third node. 
The transceiver uses sonar to interrogate the transponders, which 
respond with short pulses that are used in measuring the range and 
bearing.

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Several offshore vessels will be required to support recording, 
shooting, and housing in the marine and transition zone environments. 
Exact vessels to be used have not been determined.

Dates and Duration

    The request for incidental harassment authorization is primarily 
for the 2015 Cook Inlet open water season. The plan is to conduct 
seismic surveys in the Upper Cook unit sometime between May 13, 2015 
through May 12, 2016. The northern border of the seismic survey area 
depicted in Figure 1 takes into account the restriction that no 
activity occur between April 15 to October 15 in waters within 16 
kilometers (10 miles) of the Susitna Delta (defined as the nearshore 
area between the mouths of the Beluga and the Little Susitna rivers). A 
small wedge of the upper Cook unit falls within 16 kilometers of the 
Beluga River mouth, but survey here will occur after October 15, taking 
into account any timing restrictions with nearshore beluga habitat. The 
seismic acquisition in lower Cook unit will initially begin in late 
August or mid-September, and run until December 15 taking into account 
any self-imposed location/timing restrictions to avoid encounters with 
sea otters or Steller's eiders. The exact survey dates in a given unit 
will depend on ice conditions, timing restrictions, and other factors. 
If the upper Cook Inlet seismic surveys are delayed by spring ice 
conditions, some survey may occur in lower Cook Inlet from March to May 
to maximize use of the seismic fleet. Actual data acquisition is 
expected to occur for only 2 to 3 hours at a time during each of the 3 
to 4 daily slack tides. Thus, it is expected that the air guns will 
operate an average of about 8 to 10 total hours per day. It is 
estimated that it will take 160 days to complete both the upper and 
lower Cook units, and that no more than 777 square kilometers (300 
square miles) of survey area will be shot in 2015.

Specified Geographic Region

    The area of Cook Inlet that SAE plans to operate in has been 
divided into two subsections: Upper and Lower Cook Inlet. Upper Cook 
(2,126 square kilometers; 821 square miles) begins at the line 
delineating Cook Inlet beluga whale (Delphinapterus leucas) Critical 
Habitat Area 1 and 2, south to a line approximately 10 kilometers (6 
miles) south of both the Lower Cook (1,808 square kilometer; 698 square 
mile) begins east of Kalgin Island and running along the east side of 
lower Cook Inlet to Anchor Point (Figure 2 in SAE application).

Detailed Description of Activities

    The Notice of Proposed IHA (80 FR 14913, March 20, 2015) contains a 
full detailed description of the 3D seismic survey, including the 
recording system, sensor positioning, and seismic source. 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 
March 20, 2015 (80 FR 14913) for public comment. During the 30-day 
public comment period, NMFS received four comment letters from the 
following: The Natural Resource Defense Council (NRDC); the Marine 
Mammal Commission (MMC); Furie Operating Alaska LLC (Furie); and one 
private citizen.
    All of the public comment letters received on the Notice of 
Proposed IHA (80 FR 14913, March 20, 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: Extensive analysis of the proposed 3D seismic 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 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 analyses 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. Moreover, this activity is 
not expected to result in the death of any marine mammal species, and 
no such take is authorized.
    Comment 2: Furie supports issuance of this IHA in a timely manner 
and urge NMFS to recognize the benefits of seismic surveys and 
subsequent development of energy resources.
    Response: After careful evaluation of all comments and the data and 
information available regarding potential impacts to marine mammals and 
their habitat and to the availability of marine mammals for subsistence 
uses, NMFS has issued the final authorization to SAE to take marine 
mammals incidental to conducting a 3D seismic survey program in Cook 
Inlet for the period May 13, 2015 through May 12, 2016.
    Comment 3: The MMC recommends that NMFS defer issuance of the IHA 
until such time as NMFS can, with reasonable confidence, support a 
conclusion that the activities would affect no more than a small number 
of Cook Inlet beluga whales and have no more than a negligible impact 
on the population. The MMC recommends that NMFS defer issuance until we 
have better information on the cause or causes of ongoing decline of 
the population and a reasonable basis for determining that authorizing 
additional takes would not contribute to or exacerbate that decline. 
The MMC continues to believe that any activity that may contribute to 
or that may worsen the observed decline should not be viewed as having 
a negligible impact on the population. The NRDC states that NMFS failed 
to meet both the ``small numbers'' and ``negligible impact'' standards.
    Response: In accordance with our implementing regulations at 50 CFR 
216.104(c), we use the best available scientific evidence 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 scientific 
evidence available, NMFS determined that the impacts of the 3D seismic 
survey program, which are primarily acoustic in nature, would meet 
these standards. Moreover, SAE 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 power down or shutdown airguns 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

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exclusion (minimizing adverse effects to foraging), is expected to 
reduce both the scope and severity of potential harassment takes, 
ensuring that there are no energetic 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 the western distinct 
population segment of Steller sea lions or destroy 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 
seismic survey, and the rigorous mitigation and monitoring program, 
NMFS determined that the activity would have a negligible impact on the 
population.
    Moreover, the seismic survey would take only small numbers of 
marine mammals relative to their population sizes. The number of 
belugas likely to be taken represent less than 9.6% of the population. 
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 to calculate an estimated number of takes 
for belugas, which was estimated to be less than 10% of the stock 
abundance, 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 SAE'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 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 5 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 4: The MMC recommends that NMFS develop a policy that sets 
forth clear criteria and/or thresholds for determining what constitutes 
``small numbers'' and ``negligible impact'' for the purpose of 
authorizing incidental takes of marine mammals. The MMC understands 
that NMFS has been working on developing a policy and would welcome an 
opportunity to discuss this policy further before it is finalized.
    Response: NMFS is in the process of developing both a clearer 
policy to outline the criteria for determining what constitutes ``small 
numbers'' and an improved 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 5: The NRDC pointed by reference to the other proposed 
activities in Cook Inlet during the 2015 open water season. The NRDC 
and the MMC both note that NMFS must address the cumulative effects of 
activities in Cook Inlet on Cook Inlet beluga whales and whether the 
cumulative impacts of all the activities are having ``either 
individually or in combination'' a greater than negligible impact on 
marine mammals.
    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).
    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.
    Comment 6: The NRDC states that NMFS failed to account for survey 
duration in the estimation of beluga whale takes and that NMFS based 
beluga takes using a predictive habitat density model (Goetz et al., 
2012) that is based on data from summer months and confined to summer 
distribution when belugas are generally concentrated in the Upper 
Inlet, even though activity could occur year round.
    Response: The numerical estimation of take for beluga whales does 
consider survey duration in the calculation. The Goetz et al 2012 model 
is the best available data for beluga density in Cook Inlet. The method 
used by NMFS to estimate take uses the best available data to most 
accurately estimate the number of belugas taken. This is done by 
multiplying the density of the area surveyed on a given day by the area 
ensonified on that day of surveying to yield the number of belugas that 
were likely exposed during that day of surveying. This is then added to 
the next day of surveying and so forth in an additive model until the 
number of 30 belugas is reached. If the number of 30 belugas is reached 
using this calculation before SAE has completed their 160 days of 
proposed surveying, survey activity must cease. Additionally, if they 
finish their 160 days without reaching the limit of 30 belugas their 
activity must still cease. The model, by being additive in nature for 
each day of surveying, accounts for the duration of the survey, as well 
as capturing a more specific density value than using an Inlet-wide 
density estimate.
    Moreover, the model (or other numerical methods for estimating 
take) does not take into consideration the rigorous mitigation 
protocols that will be implemented by SAE to reduce the number of 
actual Level B harassment takes of Cook Inlet beluga whales. As 
mentioned previously, the IHA contains a condition restricting SAE's 
airgun operations within 10 mi (16 km) of the mean higher high water 
line of the Susitna Delta from April 15 through October 15. During this 
time, a significant portion of the Cook Inlet beluga whale population 
occurs in this area for feeding and calving. This setback distance 
includes the entire 160 dB radius of 5.9 mi (9.5 km) predicted for the 
full airgun array plus an additional 4.1 mi (6.5 km) of buffer, thus 
reducing the number of animals that may be exposed to Level B 
harassment thresholds. SAE is also required to shut down the airguns if 
any beluga whale is

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sighted approaching or entering the Level B harassment zone to avoid 
take. NMFS combined use of the National Marine Mammal Laboratory (NMML) 
model, which we determined to be the best available data upon which to 
base density estimates, with consideration of all of the mitigation 
measures required to be implemented to authorize 30 beluga whale takes. 
This approach is reasonable and does not contradict available science 
and data of beluga whale distribution and local abundance during the 
period of operations.
    Comment 7: The NRDC states that in the case of marine mammals other 
than beluga whales, NMFS repeated past errors associated with its use 
of raw NMML survey data. Errors in the density calculations include the 
failure to incorporate correction factors for missed marine mammals in 
the analysis and the failure to fully account for survey duration by 
multiplying densities (which are calculated on an hourly basis) by the 
number of survey days but not the number of hours in a day.
    Response: Correction factors for marine mammal surveys, with the 
exception of beluga whales, are not available for Cook Inlet. The 
primary purpose and focus of the NMFS aerial surveys in Cook Inlet for 
the past decade has been to monitor the beluga whale population. 
Although incidental observations of other marine mammals are noted 
during these surveys, they are focused on beluga whales. With the 
exception of the beluga whale, no detailed statistical analysis of Cook 
Inlet marine mammal survey results has been conducted, and no 
correction factors have been developed for Cook Inlet marine mammals. 
The only published Cook Inlet correction factor is for beluga whales. 
Developing correction factors for other marine mammals would have 
required different survey data collection and consideration of 
unavailable data such as Cook Inlet sight ability, movement patterns, 
tidal correlations and detailed statistical analyses. For example, 
other marine mammal numbers are often rounded to the nearest 10 or 100 
during the NMFS aerial survey; resulting in unknown observation bias. 
Therefore, the data from the NMFS surveys are the best available and 
number of animals taken are still likely overestimated because of the 
assumption that there is a 100% turnover rate of marine mammals each 
day.
    Survey duration was appropriately considered in the estimations by 
multiplying density by area of ensonification by number of survey days. 
NMFS does not calculate takes on an hourly basis, and, additionally, 
the multiple hours surveyed within a day are reflected in the area of 
ensonification, which considers the distance they can move within a day 
and is therefore larger than what would be covered in one hour. 
Additionally, as NMFS has used the density estimate from NMFS aerial 
surveys, multiplied by the area ensonified per day, multiplied by the 
number of days, this calculation produces the number instances of 
exposure during the survey. This is likely an overestimate of 
individuals taken by Level B harassment, as a single individual can be 
exposed on multiple days over the course of the survey, especially when 
a small patch of area is shot over a duration of five days. While 
protected species observers (PSOs) cannot detect every single animal 
within the Level B harassment zone, monitoring reports from similar 
activities indicate that sightings did not exceed anticipated 
estimates.
    Comment 8: The NRDC commented that NMFS underestimated the size of 
SAE's impact area by: (1) Using an outdated and incorrect threshold for 
behavioral take; and (2) disregarding the best available evidence on 
the potential for temporary and permanent threshold shift on mid- and 
high-frequency cetaceans and on pinnipeds.
    Response: The 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 Level B harassment takes 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). We acknowledge there is more 
recent information bearing on behavioral reactions to seismic airguns, 
but those data only illustrate how complex and context-dependent the 
relationship is between the two. See 75 FR 49710, 49716 (August 13, 
2010) (IHA for Shell seismic survey in Alaska). Accordingly, 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.
    The comment that NMFS disregarded the best available evidence on 
the potential for temporary and permanent threshold shift on mid- and 
high-frequency cetaceans and on pinnipeds does not contain any specific 
recommendations. We acknowledge there is more recent information 
available bearing on the relevant exposure levels for assessing 
temporary and permanent hearing impacts. (See NMFS' Federal Register 
notice (78 FR 78822, December 27, 2013) for NMFS' draft guidance for 
assessing the onset of permanent and temporary threshold shift.) Again, 
NMFS will be issuing guidance, but that process is not complete, so we 
did not use it to assign new thresholds for calculating take estimates 
for hearing impacts. However, we did consider the information, and it 
suggests the current 180 and 190 dB thresholds are appropriate and that 
they likely overestimate potential for hearing impacts. See 75 FR 
49710, 49715, 49724 (August 13, 2010) (IHA for Shell seismic survey in 
Alaska; responses to comment 8 and comment 27). Moreover, the required 
mitigation is designed to ensure there are no exposures at levels 
thought to cause hearing impairment, and, for several of the marine 
mammal species in the project area, mitigation measures are designed to 
reduce or eliminate exposure to Level B harassment thresholds.
    Comment 9: The NRDC comments that the proposed mitigation measures 
fail to meet the MMPA's ``least practicable adverse impact'' standard. 
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 14913, March 20, 
2015), which are repeated in the ``Mitigation'' section of this notice. 
The measures that NMFS allegedly failed to consider or

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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: SAE 
requested takes of marine mammals incidental to the seismic survey 
operations described in the IHA application, which identified airgun 
arrays as the technique SAE would employ to acquire seismic data. It 
would be inappropriate for NMFS to change the specified activity and it 
is beyond the scope of the request for takes incidental to SAE's 
operation of airguns and other active acoustic sources.
    SAE knows of no current technology scaled for industrial use that 
is reliable enough to meet the environmental challenges of operating in 
Cook Inlet. SAE is aware that many prototypes are currently in 
development, and may ultimately incorporate these new technologies into 
their evaluation process as they enter commercial viability. However, 
none of these technologies are currently ready for use on a large scale 
in Cook Inlet. As this technology is developed, SAE will evaluate its 
utility for operations in the Cook Inlet environment.
    (2) Required use of the lowest practicable source level in 
conducting airgun activity: SAE determined that the 1760 in\3\ array 
provides the data required for SAE's operations.
    (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. This 
mitigation mirrors a measure in the Incidental Take Statement for the 
2012 and 2013 Biological Opinions. Seismic survey operations involving 
the use of airguns 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. (In addition, the Alaska Department of Fish and Game (ADF&G) 
prohibits the use of airguns within 1 mi (1.6 km) of the mouth of any 
stream listed by the ADF&G on the Catalogue of Waters Important for the 
Spawning, Rearing, or Migration of Anadromous Fishes. See additional 
explanation in ``Mitigation Measures Considered but not Required'' 
section, later in this document.)
    (4) Limitation of the mitigation airgun to the longest shot 
interval necessary to carry out its intended purpose: This general 
comment contained no specific recommendations. SAE requires shot 
intervals of 50m at a speed of 4-5 knots to obtain the information from 
their survey. However NMFS has added a mitigation measure that SAE 
reduce the shot interval for the mitigation gun to one shot per minute.
    (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 SAE 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 SAE'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. SAE 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 SAE 
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 notice and the issued IHA contain a 
requirement for SAE to delay the start of airgun use or shutdown the 
airguns if a beluga whale is visually sighted or detected by passive 
acoustic monitoring 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 sightings 
of groups or cow-calf pairs.
    Comment 10: The MMC suggests additional mitigation measures are 
used including: (1) Aerial surveys, (2) passive acoustic monitoring, as 
well as (3) a 30 minute post-activity monitoring period.
    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 14913, March 20, 
2015), which are repeated in the ``Mitigation'' section of this notice. 
The measures that NMFS allegedly failed to consider or adequately 
consider are identified and discussed below:
    (1) Use of advance aerial surveys to redirect activity is not 
required for this action. Aerial surveys for this project could be used 
for monitoring the disturbance zone to the 160dB level (6.83 km). 
However, exposures that occur in this zone, or Level B takes, are 
already accounted for in the take estimation section below. Visual 
observers, which are already known to be effective in this environment, 
will adhere to strict standards for preventing animals from entering 
the 180dB/190dB injury exclusion zone, as well as monitoring for 
animals that may be traveling in the direction of or approaching the 
injury exclusion zone. The prohibitive cost of daily aerial surveys for 
a survey area of only 777km\2\, combined with the limited added value 
given the general effectiveness of vessel and land-based observers, and 
considering the fact that we believe that the activity will have a 
negligible impact even in the absence of mitigation make the suite of 
mitigation measures we have included adequate to achieve the least 
practicable adverse impact.
    (2) The passive acoustic monitoring plan for Apache Alaska 
Corporation's 2012 survey anticipated the use of a bottom-mounted 
telemetry buoy to broadcast acoustic measurements using a radio-system 
link back to a monitoring vessel. Although a buoy was deployed during 
the first week of surveying under the 2012 IHA, it was not successful. 
Upon deployment, the buoy immediately turned upside down due to the 
strong current in Cook Inlet. After retrieval, the buoy was not 
redeployed and the survey used a single omni-directional hydrophone 
lowered from the side of the mitigation vessel. During the entire 2012 
survey season, Apache's PAM equipment yielded only six confirmed marine 
mammal detections, one of which was a Cook Inlet beluga whale. The 
single Cook Inlet beluga whale detection did not, however, result in a 
shutdown procedure.
    Additionally, Joint Base Elmendorf-Fort Richardson, the National 
Marine Mammal Laboratory, and Alaska Department of Fish & Game 
conducted a 2012 study (Gillespie et al., 2013) to determine if beluga 
whale observations at the mouth of Eagle River corresponded with 
acoustic detections received by a PAMBuoy data collection system. The 
PAMBuoy data collection system was deployed in the mouth of

[[Page 29167]]

Eagle River from 12-31 August 2012. This study was a trial period 
conducted with one hydrophone at the mouth of the river. Overall, it 
was successful in detecting beluga whale echolocation clicks and 
whistles, but came with several limitations:
     The PAM system was able to reliably detect all whales 
approaching or entering the river but still performs less well than a 
human observer;
     Sounds from vessels in Cook Inlet (e.g. vessel noise) have 
a large chance of interfering with detections from PAM. The mouth of 
Eagle River has very little vessel traffic, which is likely why the 
study was successful there and not likely to be successful in Cook 
Inlet;
     PAMbouys could be a navigational hazard in Cook Inlet for 
commercial, subsistence, and sport fishing, as well as the commercial 
vessel traffic traveling through Cook Inlet;
     The limited testing in a very small area should not become 
the new standard of monitoring in the entire Cook Inlet. The tide, 
vessel traffic, bathymetry, and substrate of Cook Inlet are far more 
complex than the study area;
     It appears the hydrophone must be hardwired to the shore 
which is not practical for mobile marine seismic operations;
     Currently, deployment of the system is done by walking 
tripods onto the mudflats. This is not feasible for the vast majority 
of the SAE project area. Walking onto the mudflats in parts of Cook 
Inlet also poses a safety risk;
     The study found considerable investment would be necessary 
to develop an ice and debris proof mounting system. Other issues with 
hydrophone configuration include: At extreme low tides, the hydrophone 
was uncovered and therefore not usable; the hydrophone had to be 
located in such a position so that it could be occasionally visually 
inspected; hydrophone battery supply has to constantly be checked; the 
costs and practicalities of long-term hydrophone mounting and data 
transmission have not been determined.; and only one hydrophone was 
tested, and SAE would need several hydrophones;
     Observer sightings and acoustic detections of belugas 
generally corresponded with one another. Thus PAMBuoys would be simply 
duplicating PSO and aerial efforts;
     The wireless modem that transmits the acoustic data to the 
``base station'' was only tested to 3.2 km; and
     The study did not conclude anything about the detection 
range of the system, except that it was greater than 400 m.
    NMFS has been made aware of an over-the-side hydrophone that has 
successfully detected belugas in Eagle River, Alaska. Upon beginning 
operations, SAE has 30 days to acquire a hydrophone that covers a 
frequency range of 0.1-160 kHz to allow detecting both social and 
echolocation signals, with a system sensitivity in the range -165 to -
185 dB re1 V/[mu]Pa, and floor noise spectra similar to Beaufort Sea 
State 0. SAE will use this hydrophone during nighttime ramp-ups from 
the mitigation airgun to detect beluga whales, humpbacks, and Steller 
sea lions that may be within the 160dB disturbance zone.
    (3) A post-activity monitoring period of 30 minutes has been added 
as a requirement for this activity. This monitoring period after the 
cessation of airgun 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 11: The MMC notes that NMFS is reviewing two other IHA 
applications for proposed seismic surveys in Cook Inlet in 2015 and 
that it is not clear whether these applications are seeking separate 
authorizations for some or all of the same activities. NMFS needs to 
adopt policies and institute procedures to ensure that separate 
applications to conduct essentially the same activities in the same 
areas are considered more holistically. If indeed the applicants are 
proposing to conduct multiple seismic surveys within the same area, it 
would increase the numbers of marine mammals taken and expose beluga 
whales and other marine mammals to unnecessary, avoidable risks. 
Section 101(a)(5)(D)(ii)(I) of the MMPA directs NMFS to structure IHAs 
so that they prescribe ``other means of effecting the least practicable 
impact on such species or stock and its habitat.'' Allowing multiple 
operators to obtain separate IHAs to conduct duplicative surveys is 
inconsistent with that mandate. Data sharing and collaboration is 
critical in habitat areas used by endangered populations, such as Cook 
Inlet beluga whales. The MMC recommends that NMFS encourage SAE and 
other applicants proposing to conduct seismic surveys in Cook Inlet in 
2015 to collaborate on those surveys and, to the extent possible, 
submit a single application seeking authorization for incidental 
harassment of marine mammals.
    In a similar comment, the NRDC expressed concern over the number of 
activities proposed in the same area for the same season referencing 
applications for: Furie, Bluecrest, Buccaneer, and Apache.
    Response: We agree and have encouraged SAE to cooperate with other 
interested parties to minimize the impacts of new seismic surveys in 
the region. Apache has told NMFS that their proposed activities are a 
separate project to that of SAE. Currently, SAE works with other oil 
and gas operators in the area to enter into cooperative agreements. 
Sometimes these negotiations are successful, but at other times the 
companies cannot reach an agreement acceptable to both parties. SAE 
will continue its discussions with other operators in Cook Inlet to 
find opportunities to joint venture in oil and gas operations, 
including seismic data acquisition.
    The portion of the statute cited by the MMC refers to the need to 
require mitigation measures to ensure that the specified activity for 
which take is authorized in that particular authorization ``effects the 
least practicable impact.'' SAE proposed and NMFS has required a 
rigorous mitigation and monitoring plan to ensure that SAE's program 
meets that standard. Moreover, NMFS will not issue IHAs to other 
applicants if the negligible impact standard cannot be met.
    Lastly, there are no applications being processed for Furie or 
Buccaneer. Apache does not anticipate conducting seismic activity in 
the 2015 season. Additionally, the activities proposed by Bluecrest are 
not seismic surveys and in a far southerly portion of the Inlet, with 
no overlap with SAE's activities.
    Comment 12: Both the NRDC and the MMC comment that authorization 
should not be issued until the Cook Inlet Beluga Whale Take Recovery 
Plan is finalized and published.
    Response: The Cook Inlet Beluga Whale Recovery Plan is still under 
development and will not be available in time to authorize activities 
for the 2015 open water season. It is possible the Recovery Plan will 
be available for next season. It is not necessary to have the Recovery 
Plan finalized to authorize SAE's activity, as NMFS is still able to 
make a negligible impact determination for beluga whales.
    Comment 13: The MMC comments that various applicants in the Cook 
Inlet region have used differing density estimates for calculating take 
of marine mammal species in the Inlet and that all applicants should 
use the same densities.
    Response: The density estimates used by SAE specifically for harbor 
porpoises, harbor seals, and killer whales are the best available 
science at

[[Page 29168]]

this time. The data are from NMFS aerial surveys over a ten year period 
(2000-2012). NMFS is working with applicants to incorporate these 
density estimates into future applications and take authorizations. 
However, where applicable, density estimates and derived take 
estimation may vary based on site-specific knowledge of abundance, 
density, seasonality, or other qualities that could allow for a more 
nuanced assessment of the presence of a particular stock in a given 
location.
    Comment 14: The MMC also comments that in the application, SAE 
states it will only survey in an area of 777km\2\ but that the proposed 
action area is much larger. The MMC requests that SAE specify the area 
in which they expect to operate so that take estimations more 
accurately reflect the scope of the project.
    Response: Due to the nature of SAE's work, contracts are awarded 
throughout the season and the exact locations of operation are not 
known to SAE at the time of the application. However, SAE has provided 
how much area they plan to survey and NMFS has calculated take 
estimation using the number of survey days requested and daily 
ensonified area to calculate take instead of the 777km\2\ unique area 
specified in the application to ensure a robust calculation of 
exposures to the 160dB level.
    Comment 15: The MMC comments that SAE should be required to 
investigate and report on detection probabilities from various 
observation platforms for differing sea states and light conditions.
    Response: NMFS acknowledges that collecting detection probabilities 
from various platforms under different conditions would be very useful 
information and could better inform monitoring reports by discerning 
how many animals were likely taken. However, constructing a study to 
investigate detection probabilities requires a great deal of planning 
and many more observers than are involved in this survey. NMFS would 
like to work with the MMC in the future to discuss how best to conduct 
this work and refine detection probabilities for seismic surveys.
    Comment 16: The NRDC comments on several issues under NEPA, related 
to cumulative effects and the suite of alternatives. These comments 
are: (1) NEPA mandates that NMFS may not authorize activities while a 
programmatic EIS is underway; (2) The No Action alternative must assume 
SAE will not conduct the proposed activity; and (3) The third 
alternative with additional mitigation measures is not sufficiently 
analyzed and defined.
    Response: The NEPA analysis is an important component of our 
process. Our responses to the issues raised by the NRDC are as follows:
    (1) The regulatory text referenced by NRDC in their comments, 40 
CFR 1506.1, states that ``While work on a required program 
environmental impact statement is in progress and the action is not 
covered by an existing program statement, agencies shall not undertake 
in the interim any major Federal action covered by the program which 
may significantly affect the quality of the human environment.'' NRDC 
is likely referencing NMFS' Federal Register Notice of Intent to 
Prepare an EIS for Cook Inlet (79 FR 61616; October 14, 2014). That 
provision is not applicable here as NMFS' decision to prepare an EIS is 
not required, but rather voluntary. The programmatic EIS is meant to 
address hypothetical increasing future levels of activity in Cook 
Inlet, not a specific proposed project. Lastly, the regulatory text 
references activities that are expected to have a significant impact on 
the human environment, and NMFS has determined that this activity will 
not have such an impact, as specified in the Finding of No Significant 
Impact (FONSI). At this time, NMFS is evaluating each activity 
individually, taking into consideration cumulative impacts, with an EA, 
to determine if the action under consideration can support a FONSI.
    (2) The No Action alternative in NMFS' draft EA for this activity 
was written to reflect a situation in which NMFS did not authorize the 
activity and the survey went forward without mitigation and monitoring. 
However, after further consideration, NMFS has decided to modify the No 
Action alternative to represent a situation in which NMFS did not issue 
an authorization and the applicant did not conduct their proposed 
activity. These changes are reflected in the Final EA.
    (3) The third alternative in the EA is a scenario that includes all 
of the mitigation measures of the preferred alternative, as well as 
additional cutting edge technologies that have been suggested by 
commenters in previous authorizations, including NRDC. However, this 
alternative does not contain the more detailed analysis requested by 
NRDC because many of the included technologies are not viable at this 
time. Many are still in the developmental or preliminary testing phase, 
or do not currently have guidelines pertaining to appropriate operating 
conditions around marine mammals, such as unmanned aerial vehicles. The 
No Action alternative and the Preferred alternative both contain more 
in-depth analyses as appropriate.
    Comment 17: The NRDC comments that the dates in the proposed IHA 
suggest a curtailing of public review in violation of the 
Administrative Procedure Act.
    Response: The date provided in the proposed IHA was the date 
proposed by the applicant originally for this work. Due to the time 
required to analyze and respond to comments sufficiently, this date was 
postponed and the authorization will be effective on: May 13, 2015.
    Comment 18: The MMC comments that the use of a 2.5 turnover factor 
in take estimation of harbor seals is inappropriate. The MMC requests 
that NMFS use the same density x daily ensonified area x number of days 
formula used for the other species. The MMC also notes that if NMFS 
uses a turnover factor that it should consult the literature to create 
a more biologically relevant turnover factor than Wood et al. 2012.
    Response: After reviewing the Commission's comment, NMFS decided to 
adjust the method used to estimate take for harbor seals in Cook Inlet. 
The daily ensonified area x number of survey days x density method 
yields an estimate of instances of take that is 19,315. Not only is 
this likely an overestimate of instances, but it is also significantly 
higher than the number of individual harbor seals expected to be 
exposed, as described in more details in the Estimated Take section. 
NMFS applied the survey method used by SAE, patch shooting, and applied 
the number of days required to shoot a patch to estimate the number of 
days an animal at a given haulout could be exposed. This is an average 
of 3 days, but no more than 5. When this factor is applied to the 
overestimate of exposures by using the ensonified daily area method, 
the number of exposed seals is much lower, at 6,438. This number may be 
reduced even further as individuals could be exposed at multiple 
patches. Separately, NMFS then considered the harbor seal densities 
alongside monitoring reports from Apache's work in 2012. NMFS looked at 
the monitoring reports from Apache's aerial surveys in June and used 
correction factors from the literature to determine the number of seals 
in the water. This number was also multiplied to match the number of 
SAE's proposed survey days (160) to yield a number of 8,250 instances 
of take, notably lower than 19,315. Additionally, in their 147 days of 
surveying, Apache reported sightings of 285 seals. While it is 
understood that

[[Page 29169]]

this is lower than the actual number of exposures, as all seals in the 
160dB range are not visible, this number is 131 times smaller than the 
calculated number of exposures using the daily ensonified area method. 
These methods are discussed in greater detail in the Takes Estimation 
section of this document, but in summary we concluded that not more 
than 25% of the population of harbor seals would be taken.

Description of Marine Mammals in the Area of the Specified Activity

    Marine mammals most likely to be found in the upper Cook activity 
area are the beluga whale (Delphinapterus leucas), harbor porpoise 
(Phocoena phocoena), and harbor seal (Phoca vitulina). However, these 
species are found there in low numbers, and generally only during the 
summer fish runs (Nemeth et al. 2007, Boveng et al. 2012). These 
species are also found in the Lower Cook Inlet survey area along with 
humpback whales (Megaptera novaeangliae), minke whales (Balaenoptera 
acutorostra), gray whales (Eschrichtius robustus), killer whales 
(Orcinus orca), Dall's porpoise (Phocoenoides dalli), and Steller sea 
lions (Eumetopia jubatus). Minke whales have been considered migratory 
in Alaska (Allen and Angliss, 2014) but have recently been observed off 
Cape Starichkof and Anchor Point year-round (Owl Ridge, 2014). Humpback 
and gray whales are seasonal in Lower Cook, while the remaining species 
could be encountered at any time of the year. During marine mammal 
monitoring conducted off Cape Starichkof between May and August 2013, 
observers recorded small numbers of humpback whales, minke whales, gray 
whales, killer whales, and Steller sea lions, and moderate numbers of 
harbor porpoises and harbor seals (Owl Ridge, 2014). This survey also 
recorded a single beluga observed 6 kilometers north of Cape Starichkof 
in August 2013. The stock sizes for marine mammals found in the project 
area in Cook Inlet are shown in Table 1.

                          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
----------------------------------------------------------------------------------------------------------------
Humpback whale.................  Central North       E/D;Y..............  7,469 (0.095;       Occasionally seen
                                  Pacific.                                 5,833; 2000).       in Lower Inlet,
                                                                                               summer.
Minke whale....................  Alaska............  -;N................  1,233 (0.034; N/A;  Infrequently occur
                                                                           2003).              but reported year-
                                                                                               round.
Gray whale.....................  Eastern North       -;N................  19,126 (0.071;      Rare migratory
                                  Pacific.                                 18,017; 2007).      visitor; late
                                                                                               winter.
Killer whale...................  Alaska Resident...  -;N................  2,347 (N/A; 2,084;  Occasionally
                                                                           2009).              sighted in Lowe
                                                                                               Cook Inlet.
                                 Alaska Transient..  -:N................  345 (N/A; 303;
                                                                           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).
Dall's porpoise................  Alaska............  ...................  ..................  Infrequently found
                                                                                               in Lower Inlet.
Steller sea lion...............  Western DPS.......  E/D;Y..............  79,300 (N/A;        Primarily found in
                                                                           45,659; 2012).      lower Inlet.
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).
----------------------------------------------------------------------------------------------------------------
Source: Allen and Angliss (20142, 2013), Carretta et al. (2013), Zerbini et al. (2006)

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 Endangered Species Act (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). Humpbacks might be encountered in the vicinity of Anchor Point 
if seismic operations were to occur off the point during the summer. 
However, SAE plans, for the most part, to limit seismic activity along 
the Kenai Peninsula to during the spring and fall.

Minke Whale (Balaenoptera acutorostra)

    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. A minke whale was also 
reported off Cape Starichkof in 2011 (A. Holmes, pers. comm.) and 2013 
(E. Fernandez and C. Hesselbach, pers. comm.), suggesting this location 
is regularly used by minke whales, including during the winter. 
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 a chance 
of encountering this

[[Page 29170]]

whale during seismic operations along the Kenai Peninsula in lower Cook 
Inlet.

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 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 there are no records, but might be encountered during seismic 
operations along the Kenai Peninsula south of Ninilchik. However, 
seismic surveys are not planned in this region during the summer months 
when gray whales are most expected.

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 
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 more than 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 percent which was attributed to 
overharvesting by subsistence hunting. Subsistence hunting was 
estimated to annually remove 10 to 15 percent of the population during 
this period. Only five belugas have been harvested since 1999, yet the 
population has continued to decline, with the most recent estimate at 
only 312 animals (Allen and Angliss 2014). NMFS listed the population 
as ``depleted'' in 2000 as a consequence of the decline, and as 
``endangered'' under the Endangered Species Act (ESA) in 2008 when the 
population failed to recover following a moratorium on subsistence 
harvest. In April 2011, NMFS designated critical habitat for the beluga 
under the ESA (Figure 3). The most recent aerial survey, conducted in 
2014, suggests that the Cook Inlet population of belugas is comprised 
of 340 individuals (Shelden et al, 2015).
    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 paci[filig]cus) and 
salmon (Onchorhyncus spp.) (Moore et al. 2000). Critical Habitat Area 1 
reflects this summer distribution (Figure 5 in SAE 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 (Critical Habitat Area 2; Figure 5 in SAE 
Application). Some whales may also winter in and near Kachemak Bay.

Harbor Porpoise (Phocoena phocoena)

    Harbor porpoise are small (1.5 meters 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 meters (100 meters) 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 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. 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 could be encountered during seismic 
operations in upper Cook Inlet.

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. There is a 
remote chance that Dall's porpoise might be encountered during seismic 
operations along the Kenai Peninsula.

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 
resident stock is estimated at

[[Page 29171]]

2,347 animals and occurs from Southeast Alaska to the Bering Sea (Allen 
and Angliss 2014). Resident whales feed exclusively on fish and are 
genetically distinct from transient whales (Saulitis et al. 2000). The 
transient 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 et al. 2003, Rugh et al. 
2005a). A concentration of sightings near Homer and inside Kachemak Bay 
may represent high use or may reflect high observer-effort, given most 
records are from a whale-watching venture based in Homer. 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 
whales into beluga summering grounds have been implicated as a possible 
contributor to 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 both seismic operations in both 
upper and lower Cook Inlet.

Steller Sea Lion (Eumetopia 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 (Theragra 
chalcogramma), salmon (Onchorhyncus spp.), and arrowtooth flounder 
(Atheresthes stomias) during the summer, and walleye pollock and 
Pacific cod (Gadus macrocephalus) 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 seismic operations in upper Cook 
Inlet, but they could possibly be encountered along the Kenai 
Peninsula, especially closer to Anchor Point.

Harbor Seal (Phoca vitulina)

    With more than 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 a 
walleye 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 dozens 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 in concert 
with the spring eulachon and summer salmon runs (Nemeth et al. 2007, 
Boveng et al. 2012). In 2012, up to 100 harbor seals were observed 
hauled out at the mouths of the Theodore and Lewis rivers during 
monitoring activity associated with SAE's (with Apache) 2012 Cook Inlet 
seismic program. Montgomery et al. (2007) also found seals elsewhere in 
Cook Inlet to move in response to local steelhead (Onchorhynchus 
mykiss) and salmon runs. Harbor seals may be encountered during seismic 
operations in both upper and lower Cook Inlet.

Potential Effects of the Specified Activity on Marine Mammals

    This section includes a summary and discussion of the ways that 
components (e.g., seismic airgun operations, vessel movement) of the 
specified activity, including mitigation, 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 are expected to be taken by this activity. The 
``Negligible Impact Analysis'' section will include the analysis of how 
this specific activity will 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.
    Operating active acoustic sources, such as airgun arrays, has the 
potential for adverse effects on marine mammals. The majority of 
anticipated impacts will be from the use of 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. Based 
on available behavioral data, audiograms have been

[[Page 29172]]

derived using auditory evoked potentials, anatomical modeling, and 
other data. Southall et al. (2007) designated ``functional hearing 
groups'' for marine mammals and estimate the lower and upper 
frequencies of functional hearing of the groups. The functional groups 
and the associated frequencies are indicated below (note that animals 
are less sensitive to sounds at the outer edge of their functional 
range and most sensitive to sounds of frequencies within a smaller 
range somewhere in the middle of their functional hearing range) and 
have been modified slightly from Southall et al. 2007 to incorporate 
some newer information:
     Low frequency cetaceans (13 species of mysticetes): 
functional hearing is estimated to occur between approximately 7 Hz and 
30 kHz; (Ketten and Mountain 2009; Tubelli et al. 2012)
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz; (Southall et al. 2007)
     High frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): Functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz; (Southall et al 2007)
     Phocid pinnipeds in Water: Functional hearing is estimated 
to occur between approximately 75 Hz and 100 kHz; (Hemil[auml] et al. 
2006; Mulsow et al. 2011; Reichmuth et al. 2013) and
     Otariid pinnipeds in Water: Functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz. (Reichmuth 
et al. 2013)
    As mentioned previously in this document, nine marine mammal 
species (seven cetacean and two pinniped species) are likely to occur 
in the seismic survey area. Of the seven cetacean species likely to 
occur in SAE's project area, three classified as a low-frequency 
cetaceans (humpback, minke, gray whale), two are classified as mid-
frequency cetaceans (beluga and killer whales), and two are classified 
as a high-frequency cetaceans (Dall's and harbor porpoise) (Southall et 
al., 2007). Of the two pinniped species likely to occur in SAE's 
project area, one is classified as a phocid (harbor seal), and one is 
classified as an otariid (Steller sea lion). A species' functional 
hearing group is a consideration when we analyze the effects of 
exposure to sound on marine mammals.

1. Potential Effects of Airgun Sounds on Marine Mammals

    The effects of sounds from airgun pulses might include one or more 
of the following: Tolerance, masking of natural sounds, behavioral 
disturbance, and temporary or permanent hearing impairment or non-
auditory effects (Richardson et al., 1995). As outlined in previous 
NMFS documents, the effects of noise on marine mammals are highly 
variable, often depending on species and contextual factors (based on 
Richardson et al., 1995).
    Tolerance: Numerous studies have shown that pulsed sounds from air 
guns are often readily detectable in the water at distances of many 
kilometers. Numerous studies have also shown that marine mammals at 
distances more than a few kilometers from operating survey 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 that mammal 
group. In general, pinnipeds and small odontocetes (toothed whales) 
seem to be more tolerant of exposure to air gun pulses than baleen 
whales. Although various toothed whales, and (less frequently) 
pinnipeds have been shown to react behaviorally to airgun pulses under 
some conditions, at other times, mammals of both types have shown no 
overt reactions. 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 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/hr) for humpback and sperm whales according to the 
airgun array's operational status (i.e., active versus silent).
    Behavioral Disturbance: Marine mammals may behaviorally respond 
when exposed to anthropogenic noise. These behavioral reactions are 
often shown as: 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. The consequences of behavioral 
modification to individual fitness can range from none up to potential 
changes to growth, survival, or reproduction, depending on the context, 
duration, and degree of behavioral modification. Examples of behavioral 
modifications that could impact growth, survival or reproduction 
include: Drastic changes in diving/surfacing/swimming patterns that 
lead to stranding (such as those associated with beaked whale 
strandings related to exposure to military mid-frequency tactical 
sonar); longer-term abandonment of habitat that is specifically 
important for feeding, reproduction, or other critical needs, or 
significant disruption of feeding or social interaction resulting in 
substantive energetic costs, inhibited breeding, or prolonged or 
permanent 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 (Southall et 
al., 2007).
    Toothed whales. Few systematic data are available describing 
reactions of toothed whales to noise pulses. However, systematic work 
on sperm whales (Tyack et al., 2003) has yielded an increasing amount 
of information about responses of various odontocetes to seismic 
surveys based on monitoring studies (e.g., Stone, 2003; Smultea et al., 
2004; Moulton and Miller, 2005). Stone et al., 2003 reported reduced 
sighting rates of small odontoceter during periods of shooting during 
seismic surveys with large airgun arryas. Moulton and Miller (2004) 
also found that the range of audibility of seismic pules for mid-sized 
odontecetes was largely underestimated by models.
    Seismic operators and marine mammal observers sometimes see 
dolphins and other small toothed whales near operating airgun arrays, 
but, in general, there seems to be a tendency for most delphinids to 
show some limited avoidance of seismic vessels operating large airgun 
systems. However, 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. 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 airguns is operating than when it is

[[Page 29173]]

silent (e.g., Goold, 1996a,b,c; Calambokidis and Osmek, 1998; Stone, 
2003). 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).
    Captive bottlenose dolphins and (of more relevance in this project) 
beluga whales exhibit changes in behavior when exposed to strong pulsed 
sounds similar in duration to those typically used in seismic surveys 
(Finneran et al., 2002, 2005). However, the animals tolerated high 
received levels of sound (pk-pk level >200 dB re 1 [mu]Pa) before 
exhibiting aversive behaviors.
    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). Killer whales were found to be 
significantly farther from large airgun arrays during periods of 
shooting compared with periods of no shooting. 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.
    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. However, based on the limited 
existing evidence, belugas should not necessarily generally be grouped 
with delphinids in the ``less responsive'' category.
    Pinnipeds. Pinnipeds are not likely to show a strong avoidance 
reaction to the airgun sources used. 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 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. 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., 1995a). 
However, initial telemetry work suggests that avoidance and other 
behavioral reactions by two other species of seals, grey and harbor 
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). Even if reactions of the species occurring in the activity 
area are as strong as those evident in the telemetry study, reactions 
are expected to be confined to relatively small distances and 
durations, with no long-term effects on pinniped individuals or 
populations.
    Masking: Masking is the obscuring of sounds of interest by other 
sounds, often at similar frequencies. 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). Masking, or auditory 
interference, generally occurs when sounds in the environment are 
louder than, and of a similar frequency to, auditory signals an animal 
is trying to receive. Masking is a phenomenon that affects animals 
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, or entire populations.
    Masking occurs when anthropogenic sounds and signals (that the 
animal utilizes) overlap at both spectral and temporal scales. For the 
airgun sound generated from the seismic surveys, sound will consist of 
low frequency (under 500 Hz) pulses with extremely short durations 
(less than one second). Lower frequency man-made sounds are more likely 
to affect detection of potentially important natural sounds such as 
surf and prey noise, or communication calls for low frequency 
specialists. There is little concern regarding masking near the sound 
source due to the brief duration of these pulses and relatively longer 
silence between air gun shots (approximately 12 seconds). However, at 
long distances (over tens of kilometers away), due to multipath 
propagation and reverberation, the durations of airgun pulses can be 
``stretched'' to seconds with long decays (Madsen et al., 2006), 
although the intensity of the sound is greatly reduced.
    This could affect communication signals used by low frequency 
mysticetes when they occur near the noise band and thus reduce the 
communication space of animals (e.g., Clark et al., 2009) and cause 
increased stress levels (e.g., Foote et al., 2004; Holt et al., 2009); 
however, no baleen whales are expected to occur within the action area. 
Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior by shifting call frequencies, and/or 
increasing call volume and vocalization rates. For example, blue whales 
were found to increase call rates when exposed to seismic survey noise 
in the St. Lawrence Estuary (Di Iorio and Clark, 2010). The North 
Atlantic right whales (Eubalaena glacialis) exposed to high shipping 
noise increase call frequency (Parks et al., 2007), while some humpback 
whales respond to low-frequency active sonar playbacks by increasing 
song length (Miller et al., 2000). Additionally, beluga whales have 
been known to 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). Although some degree of 
masking is inevitable when high levels of manmade broadband sounds are 
introduced into the sea, marine mammals have evolved systems and 
behavior that function to reduce the impacts of masking. Structured 
signals, such as the echolocation click sequences of small toothed 
whales, may be readily detected 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.

[[Page 29174]]

    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 are 
known to 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, 2009; 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. Directional hearing has been demonstrated 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.
    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). In the case of the seismic survey, animals are 
not expected to be exposed to levels high enough or durations long 
enough to result in PTS.
    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 nonhuman animals. 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).
    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

[[Page 29175]]

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. Similarly, 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 we 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 seismic surveys in Cook Inlet. 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 as 
those of cetaceans, and occasionally they seem to be attracted to 
operating seismic vessels (NMFS, 2010).
    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 
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, virtually all 
neuroendocrine functions that are affected by stress--including immune 
competence, reproduction, metabolism, and behavior--are regulated by 
pituitary hormones. 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. 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 can be quickly replenished once the stress is alleviated. 
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, energy resources must be diverted 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. 
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 
which is 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 due to 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 effects of sensory impairment 
(TTS, PTS, and acoustic masking) on marine mammals remains limited, we 
assume

[[Page 29176]]

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, we 
assume that acoustic exposures sufficient to trigger onset PTS or TTS 
would be accompanied by physiological stress responses. However, marine 
mammals also 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. Additionally, no beaked whale species occur in the seismic 
survey area.
    In general, very little is known 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 belugas and some pinnipeds, are 
especially unlikely to incur non-auditory impairment or other physical 
effects. Therefore, it is unlikely that such effects would occur during 
SAE's surveys given the brief duration of exposure and the planned 
monitoring and mitigation measures described later in this document.
    Stranding and Mortality: Marine mammals close to underwater 
detonations of high explosive can be killed or severely injured, and 
the auditory organs are especially susceptible to injury (Ketten et al. 
1993; Ketten 1995). Airgun pulses are less energetic and their peak 
amplitudes have slower rise times. To date, there is no evidence that 
serious injury, death, or stranding by marine mammals can occur from 
exposure to air gun pulses, even in the case of large air gun arrays.
    However, in past IHA notices for seismic surveys, commenters have 
referenced two stranding events allegedly associated with seismic 
activities, one off Baja California and a second off Brazil. NMFS has 
addressed this concern several times, including in the Federal Register 
notice announcing the IHA for Apache Alaska's first seismic survey in 
2012. Readers are encouraged to review NMFS's response to comments on 
this matter found in 69 FR 74905 (December 14, 2004), 71 FR 43112 (July 
31, 2006), 71 FR 50027 (August 24, 2006), 71 FR 49418 (August 23, 
2006), and 77 FR 27720 (May 11, 2012).
    Beluga whale strandings in Cook Inlet are not uncommon; however, 
these events often coincide with extreme tidal fluctuations (``spring 
tides'') or killer whale sightings (Shelden et al., 2003). For example, 
in August 2012, a group of Cook Inlet beluga whales stranded in the mud 
flats of Turnagain Arm during low tide and were able to swim free with 
the flood tide. No strandings or marine mammals in distress were 
observed during the 2D test survey conducted by Apache in March 2011, 
and none were reported by Cook Inlet inhabitants. As a result, NMFS 
does not expect any marine mammals will incur serious injury or 
mortality in Cook Inlet or strand as a result of the seismic survey.

2. Potential Effects From Pingers on Marine Mammals

    Active acoustic sources other than the airguns will be used for 
SAE's oil and gas exploration seismic survey program in Cook Inlet. The 
specifications for the pingers (source levels and frequency ranges) 
were provided earlier in this document. In general, pingers are known 
to cause behavioral disturbance and are commonly used to deter marine 
mammals from commercial fishing gear or fish farms. Due to the 
potential to change marine mammal behavior, shut downs described for 
airguns will also be applied to pinger use.

Vessel Impacts

    Vessel activity and noise associated with vessel activity will 
temporarily increase in the action area during SAE's seismic survey as 
a result of the operation of nine vessels. To minimize the effects of 
vessels and noise associated with vessel activity, SAE will follow 
NMFS's Marine Mammal Viewing Guidelines and Regulations and will alter 
heading or speed if a marine mammal gets too close to a vessel. In 
addition, vessels will be operating at slow speed (4-5 knots) when 
conducting surveys and in a purposeful manner to and from work sites in 
as direct a route as possible. Marine mammal monitoring observers and 
passive acoustic devices will alert vessel captains as animals are 
detected to ensure safe and effective measures are applied to avoid 
coming into direct contact with marine mammals. Therefore, NMFS neither 
anticipates nor authorizes takes of marine mammals from ship strikes.
    Odontocetes, such as beluga whales, killer whales, and harbor 
porpoises, often show tolerance to vessel activity; however, they may 
react at long distances if they are confined by ice, shallow water, or 
were previously harassed by vessels (Richardson et al., 1995). Beluga 
whale response to vessel noise varies greatly from tolerance to extreme 
sensitivity depending on the activity of the whale and previous 
experience with vessels (Richardson et al., 1995). Reactions to vessels 
depend 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., 1999; Scheifele et al., 2005); and changes in dive, 
surfacing, and respiration patterns.
    There are few data published on pinniped responses to vessel 
activity, and most of the information is anecdotal (Richardson et al., 
1995). Generally, sea lions in water show tolerance to close and 
frequently approaching vessels and sometimes show interest in fishing 
vessels. They are less tolerant when hauled out on land; however, they 
rarely react unless the vessel approaches within 100-200 m (330-660 ft; 
reviewed in Richardson et al., 1995).

Entanglement

    Although some of SAE's equipment contains cables or lines, the risk 
of entanglement is extremely remote. Additionally, mortality from 
entanglement is not anticipated. The

[[Page 29177]]

material used by SAE and the amount of slack is not anticipated to 
allow for marine mammal entanglements.

Anticipated Effects on Marine Mammal Habitat

    The primary potential impacts to marine mammal habitat and other 
marine species are associated with elevated sound levels produced by 
airguns and other active acoustic sources. However, other potential 
impacts to the surrounding habitat from physical disturbance are also 
possible. This section describes the potential impacts to marine mammal 
habitat from the specified activity. Because the marine mammals in the 
area feed on fish and/or invertebrates there is also information on the 
species typically preyed upon by the marine mammals in the area. As 
noted earlier, upper Cook Inlet is an important feeding and calving 
area for the Cook Inlet beluga whale and critical habitat has been 
designated for this species in the seismic survey area.

Common Marine Mammal Prey in the Project Area

    Fish are the primary prey species for marine mammals in upper Cook 
Inlet. Beluga whales feed on a variety of fish, shrimp, squid, and 
octopus (Burns and Seaman, 1986). Common prey species in Knik Arm 
include salmon, eulachon and cod. Harbor seals feed on fish such as 
pollock, cod, capelin, eulachon, Pacific herring, and salmon, as well 
as a variety of benthic species, including crabs, shrimp, and 
cephalopods. Harbor seals are also opportunistic feeders with their 
diet varying with season and location. The preferred diet of the harbor 
seal in the Gulf of Alaska consists of pollock, octopus, capelin, 
eulachon, and Pacific herring (Calkins, 1989). Other prey species 
include cod, flat fishes, shrimp, salmon, and squid (Hoover, 1988). 
Harbor porpoises feed primarily on Pacific herring, cod, whiting 
(hake), pollock, squid, and octopus (Leatherwood et al., 1982). In the 
upper Cook Inlet area, harbor porpoise feed on squid and a variety of 
small schooling fish, which would likely include Pacific herring and 
eulachon (Bowen and Siniff, 1999; NMFS, unpublished data). Killer 
whales feed on either fish or other marine mammals depending on genetic 
type (resident versus transient respectively). Killer whales in Knik 
Arm are typically the transient type (Shelden et al., 2003) and feed on 
beluga whales and other marine mammals, such as harbor seal and harbor 
porpoise. The Steller sea lion diet consists of a variety of fishes 
(capelin, cod, herring, mackerel, pollock, rockfish, salmon, sand 
lance, etc.), bivalves, squid, octopus, and gastropods.

Potential Impacts on Prey Species

    With regard to fish as a prey source for cetaceans and pinnipeds, 
fish are known to hear and react to sounds and to use sound to 
communicate (Tavolga et al., 1981) and possibly avoid predators (Wilson 
and Dill, 2002). Experiments have shown that fish can sense both the 
strength and direction of sound (Hawkins, 1981). Primary factors 
determining whether a fish can sense a sound signal, and potentially 
react to it, are the frequency of the signal and the strength of the 
signal in relation to the natural background sound level.
    Fishes produce sounds that are associated with behaviors that 
include territoriality, mate search, courtship, and aggression. It has 
also been speculated that sound production may provide the means for 
long distance communication and communication under poor underwater 
visibility conditions (Zelick et al., 1999), although the fact that 
fish communicate at low-frequency sound levels where the masking 
effects of ambient noise are naturally highest suggests that very long 
distance communication would rarely be possible. Fishes have evolved a 
diversity of sound generating organs and acoustic signals of various 
temporal and spectral contents. Fish sounds vary in structure, 
depending on the mechanism used to produce them (Hawkins, 1993). 
Generally, fish sounds are predominantly composed of low frequencies 
(less than 3 kHz).
    Since objects in the water scatter sound, fish are able to detect 
these objects through monitoring the ambient noise. Therefore, fish are 
probably able to detect prey, predators, conspecifics, and physical 
features by listening to environmental sounds (Hawkins, 1981). There 
are two sensory systems that enable fish to monitor the vibration-based 
information of their surroundings. The two sensory systems, the inner 
ear and the lateral line, constitute the acoustico-lateralis system.
    Although the hearing sensitivities of very few fish species have 
been studied to date, it is becoming obvious that the intra- and inter-
specific variability is considerable (Coombs, 1981). Nedwell et al. 
(2004) compiled and published available fish audiogram information. A 
noninvasive electrophysiological recording method known as auditory 
brainstem response is now commonly used in the production of fish 
audiograms (Yan, 2004). Popper and Carlson (1998) and the Navy (2001) 
found that fish generally perceive underwater sounds in the frequency 
range of 50-2,000 Hz, with peak sensitivities below 800 Hz. Even though 
some fish are able to detect sounds in the ultrasonic frequency range, 
the thresholds at these higher frequencies tend to be considerably 
higher than those at the lower end of the auditory frequency range.
    Fish are sensitive to underwater impulsive sounds due to swim 
bladder resonance. As the pressure wave passes through a fish, the swim 
bladder is rapidly squeezed as the high pressure wave, and then the 
under pressure component of the wave, passes through the fish. The swim 
bladder may repeatedly expand and contract at the high sound pressure 
levels, creating pressure on the internal organs surrounding the swim 
bladder.
    Literature relating to the impacts of sound on marine fish species 
can be divided into the following categories: (1) Pathological effects; 
(2) physiological effects; and (3) behavioral effects. Pathological 
effects include lethal and sub-lethal physical damage to fish; 
physiological effects include primary and secondary stress responses; 
and behavioral effects include changes in exhibited behaviors of fish. 
Behavioral changes might be a direct reaction to a detected sound or a 
result of the anthropogenic sound masking natural sounds that the fish 
normally detect and to which they respond. The three types of effects 
are often interrelated in complex ways. For example, some physiological 
and behavioral effects could potentially lead to the ultimate 
pathological effect of mortality. Hastings and Popper (2005) reviewed 
what is known about the effects of sound on fishes and identified 
studies needed to address areas of uncertainty relative to measurement 
of sound and the responses of fishes. Popper et al. (2003/2004) also 
published a paper that reviews the effects of anthropogenic sound on 
the behavior and physiology of fishes.
    The level of sound at which a fish will react or alter its behavior 
is usually well above the detection level. Fish have been found to 
react to sounds when the sound level increased to about 20 dB above the 
detection level of 120 dB (Ona, 1988); however, the response threshold 
can depend on the time of year and the fish's physiological condition 
(Engas et al., 1993). In general, fish react more strongly to pulses of 
sound rather than a continuous signal (Blaxter et al., 1981), and a 
quicker alarm response is elicited when the sound signal intensity 
rises rapidly compared to sound rising more slowly to the same level.

[[Page 29178]]

    Investigations of fish behavior in relation to vessel noise (Olsen 
et al., 1983; Ona, 1988; Ona and Godo, 1990) have shown that fish react 
when the sound from the engines and propeller exceeds a certain level. 
Avoidance reactions have been observed in fish such as cod and herring 
when vessels approached close enough that received sound levels are 110 
dB to 130 dB (Nakken, 1992; Olsen, 1979; Ona and Godo, 1990; Ona and 
Toresen, 1988). However, other researchers have found that fish such as 
polar cod, herring, and capelin are often attracted to vessels 
(apparently by the noise) and swim toward the vessel (Rostad et al., 
2006). Typical sound source levels of vessel noise in the audible range 
for fish are 150 dB to 170 dB (Richardson et al., 1995).
    Carlson (1994), in a review of 40 years of studies concerning the 
use of underwater sound to deter salmonids from hazardous areas at 
hydroelectric dams and other facilities, concluded that salmonids were 
able to respond to low-frequency sound and to react to sound sources 
within a few feet of the source. He speculated that the reason that 
underwater sound had no effect on salmonids at distances greater than a 
few feet is because they react to water particle motion/acceleration, 
not sound pressures. Detectable particle motion is produced within very 
short distances of a sound source, although sound pressure waves travel 
farther.

Potential Impacts to the Benthic Environment

    SAE's seismic survey requires the deployment of a submersible 
recording system in the inter-tidal and marine zones. An autonomous 
``nodal'' (i.e., no cables) system would be placed on the seafloor by 
specific vessels in lines parallel to each other with a node line 
spacing of 402 m (0.25 mi). Each nodal ``patch'' will have 32 node 
lines parallel to each other. The lines generally run perpendicular to 
the shoreline. An entire patch will be placed on the seafloor prior to 
airgun activity. As the patches are surveyed, the node lines will be 
moved either side to side or inline to the next location. Placement and 
retrieval of the nodes may cause temporary and localized increases in 
turbidity on the seafloor. The substrate of Cook Inlet consists of 
glacial silt, clay, cobbles, pebbles, and sand (Sharma and Burrell, 
1970). Sediments like sand and cobble dissipate quickly when suspended, 
but finer materials like clay and silt can create thicker plumes that 
may harm fish; however, the turbidity created by placing and removing 
nodes on the seafloor will settle to background levels within minutes 
after the cessation of activity.
    In addition, seismic noise will radiate throughout the water column 
from airguns and pingers until it dissipates to background levels. No 
studies have demonstrated that seismic noise affects the life stages, 
condition, or amount of food resources (fish, invertebrates, eggs) used 
by marine mammals, except when exposed to sound levels within a few 
meters of the seismic source or in few very isolated cases. NMFS has 
also required a seasonal closure near the Susitna River Delta from 
April 15 to October 15, which is an essential foraging location for 
Cook Inlet belugas. Where fish or invertebrates did respond to seismic 
noise, the effects were temporary and of short duration. Consequently, 
disturbance to fish species due to the activities associated with the 
seismic survey (i.e, placement and retrieval of nodes and noise from 
sound sources) will be short term and fish will be expected to return 
to their pre-disturbance behavior once seismic survey activities cease.
    Based on the preceding discussion, the activity is not expected to 
have any habitat-related effects that could cause significant or long-
term consequences for individual marine mammals or their populations.

Mitigation

    In order to issue an incidental take authorization (ITA) 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 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).

Mitigation Measures in SAE's Application

    For the mitigation measures, SAE listed the following protocols to 
be implemented during its seismic survey program in Cook Inlet.
1. Operation of Mitigation Airgun at Night
    SAE will conduct both daytime and nighttime operations. Nighttime 
operations will be initiated only if a ``mitigation airgun'' (typically 
the 10 in\3\) has been continuously operational from the time that PSO 
monitoring has ceased for the day. Seismic activity will not ramp up 
from an extended shut-down (i.e., when the airgun has been down with no 
activity for at least 10 minutes) during nighttime operations, and 
survey activities will be suspended until the following day. At night, 
the vessel captain and crew will maintain lookout for marine mammals 
and will order the airgun(s) to be shut down if marine mammals are 
observed in or about to enter the established exclusion zones.
2. Exclusion and Disturbance Zones
    SAE will establish exclusion zones to avoid Level A harassment 
(``injury exclusion zone'') of all marine mammals and to avoid Level B 
harassment (``disturbance exclusion zone'') of any beluga whales or 
groups of five or more killer whales or harbor porpoises detected 
within the designated zones. The injury exclusion zone will correspond 
to the area around the source within which received levels equal or 
exceed 180 dB re 1 [micro]Pa [rms] for cetaceans and 190 dB re 1 
[micro]Pa [rms] for pinnipeds, and SAE will shut down or power down 
operations if any marine mammals are seen approaching or entering this 
zone (more detail below). The disturbance exclusion zone will 
correspond to the area around the source within which received levels 
equal or exceed 160 dB re 1 [micro]Pa [rms] and SAE will implement 
power down and/or shutdown measures, as appropriate, if any beluga 
whales, humpback whales, Steller sea lions, or group of five or more 
killer whales or harbor porpoises are seen entering or approaching the 
disturbance exclusion zone.
3. Power Down and Shutdown Procedures
    A power down is the immediate reduction in the number of operating 
energy sources from a full array firing to a mitigation airgun. A 
shutdown is the immediate cessation of firing of all energy sources. 
The arrays will be immediately powered down whenever a marine mammal is 
sighted approaching close to or within the applicable exclusion zone of 
the full arrays but is outside the applicable exclusion zone of the 
single source. If a marine mammal is sighted within the applicable 
exclusion zone of the single energy source, the entire array will be 
shutdown (i.e., no sources firing). Following a power down or a 
shutdown, airgun activity will not resume until the marine mammal has 
clearly left the applicable injury or disturbance exclusion zone. The 
animal will be considered to have cleared the zone if it: (1) Is 
visually observed to have left the zone; (2) has not been seen within 
the zone for 15 minutes in the case of pinnipeds and small odontocetes; 
or (3)

[[Page 29179]]

has not been seen within the zone for 30 minutes in the case of large 
odontocetes, including killer whales and belugas.
    Visual monitoring by qualified PSOs will continue for 30 minutes 
after a shutdown or at the end of a period of seismic surveying to 
monitor for animals returning to the previously ensonified area.
4. Ramp-Up Procedures
    A ramp-up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of air guns firing until the full volume is achieved. The 
purpose of a ramp-up (or ``soft start'') is to ``warn'' cetaceans and 
pinnipeds in the vicinity of the airguns and to provide the time for 
them to leave the area and thus avoid any potential injury or 
impairment of their hearing abilities.
    During the seismic survey, the seismic operator will ramp up the 
airgun array slowly at a rate of no more than 6 dB per 5-minute period. 
Ramp-up is used at the start of airgun operations, after a power- or 
shut-down, and after any period of greater than 10 minutes in duration 
without airgun operations (``extended 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, and Steller sea lions), or 30 minutes for large 
odontocetes (e.g., killer whales and beluga whales).
5. Speed or Course Alteration
    If a marine mammal is detected outside the 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 avoid the marine mammal and also minimize the 
effect on the seismic program. This can be used in coordination with a 
power down procedure. The marine mammal activities and movements 
relative to the seismic 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, power down, or shut down of the 
airgun(s).
6. Measures for Beluga Whales and Groups of Killer Whales and Harbor 
Porpoises
    The following are additional protective measures for beluga whales 
and groups of five or more killer whales and harbor porpoises. 
Specifically, a 160-dB vessel monitoring zone will 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 will not commence until the animals are no longer 
present within the 160-dB disturbance zone. Whenever any 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 airguns 
may be powered down before the animal is within the 160-dB disturbance 
zone, as an alternative to a complete shutdown. If a power down is not 
sufficient, the sound source(s) will be shut-down until the animals are 
no longer present within the 160-dB zone.

Additional Mitigation Measures Required by NMFS

    In addition to the mitigation measures above, NMFS requires 
implementation of the following mitigation measures.
    SAE will not operate airguns within 10 miles (16 km) of the mean 
higher high water (MHHW) 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 15-October 15. Activities may occur within this area from 
October 16-April 14.
    A ``mitigation airgun'' (10in\3\) will be operated at approximately 
one shot per minute, only during daylight and when there is good 
visibility, and will not be operated for longer than 3 hours in 
duration. In cases when the next start-up after the turn is expected to 
be during lowlight or low visibility, use of the mitigation airgun may 
be initiated 30 minutes before darkness or low visibility conditions 
occur and may be operated until the start of the next seismic 
acquisition line. The mitigation gun must still be operated at 
approximately one shot per minute.
    When nighttime operations ramp up from the mitigation airgun, SAE 
will be required to use passive acoustic monitoring for at least 30 
minutes prior to ramp-up to detect beluga whales, humpback whales, and 
Steller sea lions that may be within the 160dB disturbance zone. The 
support vessel must remain sufficiently distant from the seismic source 
vessel to ensure that beluga whales, if present and vocalizing, can be 
detected. Passive acoustic monitoring must continue throughout seismic 
operations occurring between local sunset and sunrise.
    NMFS requires that SAE must suspend seismic operations if a live 
marine mammal stranding is reported in Cook Inlet coincident to, or 
within 72 hours of, seismic survey activities involving the use of 
airguns (regardless of any suspected cause of the stranding). The 
shutdown must occur if the animal is within a distance two times that 
of the 160 dB isopleth of the largest airgun array configuration in 
use. This distance was chosen to create an additional buffer beyond the 
distance at which animals would typically be considered harassed, as 
animals involved in a live stranding event are likely compromised, with 
potentially increased susceptibility to stressors, and the goal is to 
decrease the likelihood that they are further disturbed or impacted by 
the seismic survey, regardless of what the original cause of the 
stranding event was. Shutdown procedures will remain in effect until 
NMFS determines and advises SAE that all live animals involved in the 
stranding have left the area (either of their own volition or following 
herding by responders).
    Finally, NMFS requires that if any marine mammal species are 
encountered during seismic activities for which take is not authorized, 
and are likely to be exposed to sound pressure levels (SPLs) greater 
than or equal to 160 dB re 1 [micro]Pa (rms), then SAE must alter speed 
or course, power down or shut down the sound source to avoid take of 
those species.
Mitigation Conclusions
    NMFS has carefully evaluated SAE's mitigation measures and 
considered a range of other measures in the context of ensuring that 
NMFS prescribes the

[[Page 29180]]

means of aeffecting the least practicable adverse impact on the 
affected marine mammal species and stocks and their habitat. Our 
evaluation of mitigation 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 measures are 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 below:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of seismic airguns, or other activities expected to result in 
the take of marine mammals (this goal may contribute to 1, above, or to 
reducing harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of seismic airguns or other activities expected to 
result in the take of marine mammals (this goal may contribute to 1, 
above, or to reducing harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of seismic airguns or other activities expected to result in the 
take of marine mammals (this goal may contribute to 1, above, or to 
reducing the severity of harassment takes only).
    5. 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.
    6. 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 our evaluation of the applicant's mitigation measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means of effecting the least 
practicable adverse impact on marine mammals species or stocks and 
their habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance.

Monitoring and Reporting

Monitoring Measures

1. Visual Vessel-based Monitoring
    Vessel-based monitoring for marine mammals will be done by 
experienced PSOs throughout the period of marine survey activities. 
PSOs will monitor the occurrence and behavior of marine mammals near 
the survey vessel during all daylight periods (nautical dawn to 
nautical dusk) during operation and during most daylight periods when 
airgun operations are not occurring. PSO duties will include watching 
for and identifying marine mammals, recording their numbers, distances, 
and reactions to the survey operations, and documenting observed ``take 
by harassment'' as defined by NMFS.
    A minimum number of seven PSOs (two per source vessel and two per 
support vessel, with one additional PSO on the mitigation vessel to 
operate the hydrophone) will be required onboard the survey vessel to 
meet the following criteria: (1) 100 percent monitoring coverage during 
all periods of survey operations in daylight (nautical twilight-dawn to 
nautical twilight-dusk; (2) maximum of 4 consecutive hours on watch per 
PSO; and (3) maximum of 12 hours of watch time per day per PSO.
    PSO teams will consist of NMFS-approved field biologists. An 
experienced field crew leader will supervise the PSO team onboard the 
survey vessel. SAE will have PSOs aboard three vessels: the two source 
vessels and one support vessel (M/V Dreamcatcher). Two PSOs will be on 
the source vessels, and three PSOs will be on the support vessel to 
observe and implement the exclusion, power down, and shut down areas. 
When marine mammals are about to enter or are sighted within designated 
harassment and exclusion zones, airgun or pinger operations will be 
powered down (when applicable) or shut down immediately. The vessel-
based observers will watch for marine mammals during all periods when 
sound sources are in operation and for a minimum of 30 minutes prior to 
the start of airgun or pinger operations after an extended shut down as 
well as 30 minutes after the end of airgun operation.
    The observer(s) will watch for marine mammals from the best 
available vantage point on the source and support vessels, typically 
the flying bridge. The observer(s) will scan systematically with the 
unaided eye and 7x50 reticle binoculars, assisted by 40x80 long-range 
binoculars.
    All observations will be recorded in a standardized format. When a 
mammal sighting is made, the following information about the sighting 
will be recorded:
     Species, group size, age/size/sex categories (if 
determinable), sighting cue, behavior when first sighted and after 
initial sighting, time of sighting, heading (if consistent), bearing 
and distance from the PSO, direction and speed relative to vessel, 
apparent reaction to activities (e.g., none, avoidance, approach, 
paralleling, etc.), closest point of approach, and behavioral pace;
     Time, location, speed, activity of the vessel (e.g., 
seismic airguns off, pingers on, etc.), sea state, ice cover, 
visibility, and sun glare; and
     The positions of other vessel(s) in the vicinity of the 
PSO location.
    The ship's position, speed of support vessels, and water 
temperature, water depth, sea state, ice cover, visibility, and sun 
glare will also be recorded at the start and end of each observation 
watch, every 30 minutes during a watch, and whenever there is a change 
in any of those variables.
2. Visual Shore-Based Monitoring
    In addition to the vessel-based PSOs, SAE will utilize shore-based 
monitoring daily in the event of summer seismic activity occurring 
nearshore to Cook Inlet beluga Critical Habitat Area 1, to visually 
monitor for marine mammals. The shore-based PSOs will scan the area 
prior to, during, and after the airgun operations and will be in 
contact with the vessel-based PSOs via radio to communicate sightings 
of marine mammals approaching or within the project area. This 
communication will allow the vessel-based observers to go on a 
``heightened'' state of alert regarding occurrence of marine mammals in 
the area and aid in timely implementation of mitigation measures.

Reporting Measures

    Immediate reports will be submitted to NMFS if 25 belugas are 
detected in the Level B disturbance exclusion zone to evaluate and make 
necessary adjustments to monitoring and mitigation. If the number of 
detected

[[Page 29181]]

takes for any marine mammal species is met or exceeded, SAE will 
immediately cease survey operations involving the use of active sound 
sources (e.g., airguns and pingers) and notify NMFS.
1. Weekly Reports
    SAE will submit a weekly field report to NMFS Headquarters as well 
as the Alaska Regional Office, no later than close of business each 
Thursday during the weeks when in-water seismic survey activities take 
place. The weekly field reports will summarize species detected 
(number, location, distance from seismic vessel, behavior), in-water 
activity occurring at the time of the sighting (discharge volume of 
array at time of sighting, seismic activity at time of sighting, visual 
plots of sightings, and number of power downs and shutdowns), 
behavioral reactions to in-water activities, and the number of marine 
mammals exposed.
2. Monthly Reports
    Monthly reports will be submitted to NMFS for all months during 
which in-water seismic activities take place. 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 all seismic operations and marine mammal 
sightings.
     Species, number, location, distance from the vessel, and 
behavior of any sighted marine mammals, as well as associated seismic 
activity (number of power-downs and shutdowns), observed throughout all 
monitoring activities.
     An estimate of the number (by species) of: (i) Pinnipeds 
that have been exposed to the seismic 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 seismic 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.
     A description of the implementation and effectiveness of 
the: (i) Terms and conditions of the Biological Opinion's Incidental 
Take Statement (ITS); 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.
3. Annual Reports
    SAE will submit an annual report to NMFS's Permits and Conservation 
Division within 90 days after the end of operations on the water or at 
least 90 days prior to requiring a subsequent authorization, whichever 
comes first. The annual report will include:
     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 seismic 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) numbers of animals 
detected in the 160 dB harassment (disturbance exclusion) zone.
    NMFS will review the draft annual report. SAE must then submit a 
final annual report to the Chief, Permits and Conservation Division, 
Office of Protected Resources, NMFS, within 30 days after receiving 
comments from NMFS on the draft annual report. If NMFS has no comment 
on the draft annual report, the draft report shall be considered to be 
the final report.
4. Notification of Injured or Dead Marine Mammals
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this 
Authorization, such as an injury (Level A harassment), serious injury 
or mortality (e.g., ship-strike, gear interaction, and/or 
entanglement), SAE shall immediately cease the specified activities and 
immediately report the incident to the Chief of the Permits and 
Conservation Division, Office of Protected Resources, NMFS, her 
designees, and the Alaska Regional Stranding Coordinators. The report 
must include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with SAE to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. SAE may not resume their 
activities until notified by NMFS via letter or email, or telephone.
    In the event that SAE 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), 
SAE will immediately report the incident to the Chief of the Permits 
and Conservation Division, Office of Protected Resources, NMFS, her 
designees, and the NMFS Alaska Stranding Hotline. The report must 
include the same information identified in the paragraph above. 
Activities may continue while NMFS reviews the circumstances of the 
incident. NMFS will work with SAE to determine whether modifications in 
the activities are appropriate.
    In the event that SAE 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 authorized activities (e.g., previously wounded 
animal, carcass with moderate to advanced decomposition, or scavenger 
damage), SAE shall report the incident to the Chief of the Permits and 
Conservation Division, Office of Protected Resources, NMFS, her 
designees, the NMFS Alaska Stranding Hotline, and the Alaska

[[Page 29182]]

Regional Stranding Coordinators within 24 hours of the discovery. SAE 
shall provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Network. Activities may continue while NMFS reviews 
the circumstances of the incident.

Monitoring Results From Previously Authorized Activities

    While SAE has previously applied for Authorizations for work in 
Cook Inlet, Alaska, work was not conducted upon receiving the 
Authorization. SAE has previously conducted work under Incidental 
Harassment Authorizations in the Beaufort Sea.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, 
section 3(18) of 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; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment]. Only take by Level B behavioral 
harassment is anticipated as a result of the seismic survey program 
with mitigation measures. Anticipated impacts to marine mammals are 
associated with noise propagation from the sound sources (e.g., airguns 
and pingers) used in the seismic survey; no take is expected to result 
from vessel strikes because of the slow speed of the vessels (4-5 
knots).
    SAE requests authorization to take nine marine mammal species by 
Level B harassment. These nine marine mammal species are: Cook Inlet 
beluga whale; humpback whale; minke whale; killer whale; harbor 
porpoise; Dall's porpoise; gray whale; harbor seal; and Steller sea 
lion.
    For impulse sounds, such as those produced by airgun(s) used in the 
seismic survey, NMFS uses the 160 dB re 1 [mu]Pa (rms) isopleth to 
indicate the onset of Level B harassment. The current Level A (injury) 
harassment threshold is 180 dB (rms) for cetaceans and 190 dB (rms) for 
pinnipeds. The NMFS annual aerial survey data from 2002-2012 was used 
to derive density estimates for each species (number of individuals/
km\2\), and is a large source of the data in the Goetz et al 2012 model 
used for beluga density estimation in this Authorization.

Applicable Zones for Estimating ``Take by Harassment''

    To estimate potential takes by Level B harassment for this 
Authorization, as well as for mitigation radii to be implemented by 
PSOs, ranges to the 160 dB (rms), 180 dB, and 190 dB isopleths were 
estimated at three different water depths (5 m, 25 m, and 45 m) . The 
distances to this threshold for the nearshore survey locations are 
provided in Table 4 in SAE's application. The distances to the 
thresholds provided in Table 4 in SAE's application correspond to the 
broadside and endfire directions.
    Compared to the airguns, the relevant isopleths for the positioning 
pinger are quite small. The distances to the 190, 180, and 160 dB (rms) 
isopleths are 1 m, 3 m, and 25 m (3.3, 10, and 82 ft), respectively.

Estimates of Marine Mammal Density

    SAE used one method to estimate densities for Cook Inlet beluga 
whales and another method for the other marine mammals in the area 
expected to be taken by harassment. Both methods are described in this 
document.
1. Beluga Whale Density Estimates
    In similar fashion to a previous IHA issued to Apache, SAE used a 
habitat-based model developed by Goetz et al. (2012a). Information from 
that model has once again been used to estimate densities of beluga 
whales in Cook Inlet and we consider it to be the best available 
information on beluga density. A summary of the model is provided here, 
and additional detail can be found in Goetz et al. (2012a). To develop 
NMML's estimated densities of belugas, Goetz et al. (2012a) developed a 
model based on aerial survey data, depth soundings, coastal substrate 
type, environmental sensitivity index, anthropogenic disturbance, and 
anadromous fish streams to predict beluga densities throughout Cook 
Inlet. The result of this work is a beluga density map of Cook Inlet, 
which easily sums the belugas predicted within a given geographic area. 
NMML developed its predictive habitat model from the distribution and 
group size of beluga whales observed between 1994 and 2008. A 2-part 
``hurdle'' model (a hurdle model in which there are two processes, one 
generating the zeroes and one generating the positive values) was 
applied to describe the physical and anthropogenic factors that 
influence (1) beluga presence (mixed model logistic regression) and (2) 
beluga count data (mixed model Poisson regression). Beluga presence was 
negatively associated with sources of anthropogenic disturbance and 
positively associated with fish availability and access to tidal flats 
and sandy substrates. Beluga group size was positively associated with 
tidal flats and proxies for seasonally available fish. Using this 
analysis, Goetz et al. (2012) produced habitat maps for beluga 
presence, group size, and the expected number of belugas in each 1 
km\2\ cell of Cook Inlet. The habitat-based model developed by NMML 
uses a Geographic Information System (GIS). A GIS is a computer system 
capable of capturing, storing, analyzing, and displaying geographically 
referenced information; that is, data identified according to location. 
However, the Goetz et al. (2012) model does not incorporate seasonality 
into the density estimates. Rather, SAE factors in seasonal 
considerations of beluga density into the design of the survey 
tracklines and locations (as discussion in more detail later in this 
document) in addition to other factors such as weather, ice conditions, 
and seismic needs.
2. Non-Beluga Whale Species Density Estimates
    Densities of other marine mammal species in the project area were 
estimated from the annual aerial surveys conducted by NMFS for Cook 
Inlet beluga whale between 2000 and 2012 in June (Rugh et al., 2000, 
2001, 2002, 2003, 2004b, 2005b, 2006, 2007; Shelden et al., 2008, 2009, 
2010, 2012; Hobbs et al., 2011). These surveys were flown in June to 
collect abundance data of beluga whales, but sightings of other marine 
mammals were also reported. Although these data were only collected in 
one month each year, these surveys provide the best available 
relatively long term data set for sighting information in the project 
area. The general trend in marine mammal sighting is that beluga whales 
and harbor seals are the species seen most frequently in upper Cook 
Inlet, with concentrations of harbor seals near haul out sites on 
Kalgin Island and of beluga whales near river mouths, particularly the 
Susitna River. The other marine mammals of interest for this 
authorization (humpback whales, gray whales, minke whales, killer 
whales, harbor porpoises, Dall's porpoises, Steller sea lions) are 
observed infrequently in upper Cook Inlet and more commonly in lower 
Cook Inlet. In addition, these densities are calculated based on a 
relatively large area that was surveyed, much larger than the proposed 
area for a given year of seismic data acquisition. Furthermore, these 
annual aerial surveys are conducted only in June (numbers from August 
surveys were not used because the area

[[Page 29183]]

surveyed was not provided), so it does not account for seasonal 
variations in distribution or habitat use of each species.
    Table 5 in SAE's application provides a summary of the results of 
NMFS aerial survey data collected in June from 2000 to 2012. To 
estimate density of marine mammals, total number of individuals (other 
species) observed for the entire survey area by year (surveys usually 
last several days) was divided by the approximate total area surveyed 
for each year (density = individuals/km\2\). As noted previously, the 
total number of animals observed for the entire survey includes both 
lower and upper Cook Inlet, so the total number reported and used to 
calculate density is higher than the number of marine mammals 
anticipated to be observed in the project area. In particular, the 
total number of harbor seals observed on several surveys is very high 
due to several large haul outs in lower and middle Cook Inlet. The 
table below (Table 2) provides average density estimates for gray 
whales, harbor seals, harbor porpoises, killer whales, and Steller sea 
lions over the 2000-2012 period.

                 Table 2--Animal Densities in Cook Inlet
------------------------------------------------------------------------
                                             Average density  (animals/
                  Species                              km\2\)
------------------------------------------------------------------------
Humpback whale............................  0.0024
Gray whale................................  9.45E-05
Minke whale...............................  1.14E-05
Killer whale..............................  0.0008
Dall's porpoise...........................  0.0002
Harbor porpoise...........................  0.0033
Harbor seal...............................  0.28
Steller sea lion..........................  0.008
------------------------------------------------------------------------

Calculation of Takes by Harassment

1. Beluga Whales
    As a result of discussions with NMFS, SAE has used the NMML model 
(Goetz et al., 2012a) for the estimate of takes in this Authorization. 
SAE has established two zones (Zone 1 and Zone 2) and proposes to 
conduct seismic surveys within all, or part of these zones; to be 
determined as weather, ice, and priorities dictate, which can be found 
in the attached figure which will be posted at https://www.nmfs.noaa.gov/pr/permits/incidental/oilgas.htm
    Based on information using Goetz et al. model (2012a), SAE derived 
one density estimate for beluga whales in Upper Cook Inlet (i.e., north 
of the Forelands) and another density estimate for beluga whales in 
Lower Cook Inlet (i.e., south of the Forelands). The density estimate 
for Upper Cook Inlet is 0.0212 and is 0.0056 for Lower Cook Inlet. 
SAE's seismic operational area will be determined as weather, ice, and 
priorities dictate. SAE has requested a maximum allowed take for Cook 
Inlet beluga whales of 30 individuals. SAE will operate in a portion of 
the total seismic operation area of 3,934 km\2\ (1,519 mi\2\), such 
that when one multiplies the anticipated beluga whale density based on 
the seismic survey operational area times the area to be ensonified to 
the 160-dB isopleth of 9.5 km (5.9 mi) and takes the number of days 
into consideration, estimated takes will not exceed 30 beluga whales.
    In order to estimate when that level is reached, SAE is using a 
formula based on the total potential area of each seismic survey 
project zone (including the 160 dB buffer) and the average density of 
beluga whales for each zone. Daily take is calculated as the product of 
a daily ensonified area times the density in that area. Then daily take 
is summed across all the days of the survey until the survey approaches 
30 takes.

      Table 3--Expected Beluga Whale Takes, Total Area of Zone, and Average Beluga Whale Density Estimates
----------------------------------------------------------------------------------------------------------------
                                           Expected Beluga
                                           takes from  NMML    Total area of
                                          model  (including      zone (km2)         Average take density (dx)
                                             the  160 dB       (including the
                                               buffer)         160 dB buffer)
----------------------------------------------------------------------------------------------------------------
Zone 1--Upper Inlet.....................                 28              2,126  d1 = 0.0212
Zone 2--Lower Inlet.....................                 29              1,808  d2 = 0.0056
----------------------------------------------------------------------------------------------------------------

    SAE will limit surveying in the seismic survey area (Zones 1 and 2 
presented in Figures 1 and 2 of SAE's application) to ensure a maximum 
of 30 beluga takes during the open water season. In order to ensure 
that SAE does not exceed 30 beluga whale takes, the following equation 
is being used:
[GRAPHIC] [TIFF OMITTED] TN20MY15.000

    This formula also allows SAE to have flexibility to prioritize 
survey locations in response to local weather, ice, and operational 
constraints. SAE may choose to survey portions of a zone or a zone in 
its entirety, and the analysis in this Authorization takes this into 
account. Using this formula, if SAE surveys the entire area of Zone 1 
(1,319 km\2\), then essentially none of Zone 2 will be surveyed because 
the input in the calculation denoted by d2A2 will 
essentially need to be zero to ensure that the total allotted take of 
beluga whales is not exceeded. The use of this formula will ensure that 
SAE's seismic survey will not exceed 30 calculated beluga takes.
    Operations are required to cease once SAE has conducted seismic 
data acquisition in an area where multiplying the applicable density by 
the total ensonified area out to the 160-dB isopleth equaled 30 beluga 
whales, using the equation provided above. If 30 belugas are visually 
observed before the calculation reaches 30 belugas, SAE is also 
required to cease survey activity.
2. Humpback Whales
    Although the density for humpback whales in Cook Inlet according to 
NMML surveys is 0.0024 animals per km\2\, it is widely known that 
humpbacks occur with greater frequency in the lower inlet, and are 
rarely sighted in the upper inlet. Apache data has indicated that take 
of two humpback whales is possible, but existing observation data of 
humpback whales in Cook Inlet

[[Page 29184]]

supports that this is extremely unlikely. No more than two humpback 
whales have ever been recorded in a single season by NMFS observers or 
PSOs on board seismic vessels in Cook Inlet. Therefore, while the 
occurrence of two humpbacks is rare but possible, it is unlikely that 
more than five humpbacks will be exposed by Level B harassment based on 
known distribution of humpbacks in Cook Inlet.
3. Steller Sea Lions
    The density estimate used in the Authorization for Steller sea 
lions included NMFS data that includes animals at sea lion haulouts 
that are within Cook Inlet, but are well south of the action area. An 
anomalous sighting of 20 animals occurred along the southern edge of 
the action area, far from any known haulouts or rookeries (such a large 
congregation of Steller sea lions far from haulouts or rookeries is 
unusual) which is included in NMFS' revised estimate of Steller sea 
lion take, but does not include animals observed outside of the action 
area. Based on monitoring reports of other seismic activities in Cook 
Inlet, there are typically one or two Steller sea lions within the 
action area per year. Two individuals were observed by Apache PSOs in 
2014 and three groups totaling about four animals were observed in 
2012. Because of this data, NMFS has revised its take estimate to 25 
individuals, which will account for what one may expect seismic vessels 
implementing mitigation measures to encounter in a year, but allows for 
the possibility that the survey may encounter an anomalously large 
group such as was observed by NMFS aerial observers near the southern 
portion of the action area in 2006.
    While the NMML survey data reports an average density of 0.008281 
Steller sea lions per km\2\ in the action area, NMFS aerial survey data 
indicate a maximum density of 0.003518 Steller sea lions per km\2\ with 
in the action area (20 animals/5,684 km\2\). Given the size and 
location of the action area, we have determined that authorizing take 
of 25 Steller sea lions is most appropriate and reflects appropriate 
use of the best available scientific data.
4. Harbor seals
    As noted above, using the daily ensonified area x number of survey 
days x density method results in a reasonable estimate of the instances 
of take, but likely significantly overestimates the number of 
individual animals expected to be taken. With most species, even this 
overestimated number is still very small, and additional analysis is 
not really necessary to ensure minor impacts. However, because of the 
number and density of harbor seals in the area, a more accurate 
understanding of the number of individuals likely taken is necessary to 
fully analyze the impacts and ensure that the total number of harbor 
seals taken is small.
    As described below, we believe that the modeled number of estimated 
instances of take referenced above may actually be high, based on 
monitoring results from the area. The density estimate from NMFS aerial 
surveys includes harbor seal haulouts far south of the action area that 
may never move to an ensonified area. Further, we believe that we can 
reasonably estimate the comparative number of individual harbor seals 
that will likely be taken, based both on monitoring data, operational 
information, and an a general understanding of harbor seal habitat use.
    Using the daily ensonified area x number of survey days x density 
formula (based on surveying 6.7 source lines per day), the number of 
instances of exposure above the 160-dB threshold estimated for SAE's 
activity in Cook Inlet is 19,315. However, when we examine monitoring 
data from previous activities, it is clear this number is an 
overestimate--compared to both aerial and vessel based observation 
efforts. Apache's monitoring report from 2012 details that they saw 
2,474 harbor seals from 29 aerial flights (over 29 days) in the 
vicinity of the survey during the month of June, which is the peak 
month for harbor seal haulout. In surveying the literature, correction 
factors to account for harbor seals in water based on land counts vary 
from 1.2 to 1.65 (CITE). Using the most conservative factor of 1.65 
(allowing us to consider that some of the other individuals on land may 
have entered the water at other points in day), if Apache saw 2,474 
seals hauled out then there were an estimated 1,500 seals in the water 
during those 29 days. If, because there were only 29 surveys, we 
conservatively multiply by 5.5 to estimate the number of seals that 
might have been seen if the aerial surveys were conducted for 160 days, 
this yields an estimate of 8,250 instances of seal exposure in the 
water, which is far less than the estimated 19,315. That the number of 
potential instances of exposure is likely less than 19,315 is also 
supported by the visual observations from PSOs on board vessels. PSOs 
sighted a total of 285 seals in water over 147 days of activity which 
would rise to about 310 is adjusted to reflect 160 days of effort. 
Given the size of the disturbance zone for these activities, it is 
likely that not all harbor seals that were exposed were seen by PSOs, 
however 310 is still far less than the estimate of 19,315 given by the 
density calculations.
    Further, based on the residential nature of harbor seals and the 
number of patches SAE plans to shoot, it is possible to reasonably 
estimate the number of individual harbor seals exposed, given the 
instances of exposures. Based on an estimate of 32 patches in 160 days, 
SAE will shoot one patch in 5 days. If seals are generally returning to 
haulouts in the survey area over the 5 days of any given patch shoot, 
than any given seal in the area could be exposed a minimum of one day 
and a maximum of all five days, with an average of 3 days. If the 
original exposure estimate using density is 19,315 exposures, then when 
divided by three (the average number of times an animal could be 
exposed during the shooting of one patch), the expected number of 
individuals exposed is 6,438, which is approximately 28% of the 
population. This number is also likely an overestimate given that 
adjoining patches may be shot, meaning the same seals could be exposed 
over multiple patches. Given these multiple methods, as well as the 
behavioral preferences of harbor seals for haulouts in certain parts of 
the Inlet (Montgomery et al., 2007), and high concentrations at 
haulouts in the lower Inlet (Boveng et al.), it is unreasonable to 
expect that more than 25% of the population, or 5,725 individuals, will 
be taken by Level B harassment during SAE's activity.
5. Other Marine Mammal Species
    The estimated takes of other Cook Inlet marine mammals that may be 
potentially harassed during the seismic surveys was calculated by 
multiplying the following:
     Average density estimates (derived from NMFS aerial 
surveys from 2000-2012 and presented in Table 3 in this document)
     the area ensonified by levels >=160 dB re [mu]Pa rms in 
one day (calculated using the total ensonified area per day of 414.92 
km\2\, which is derived by applying the buffer distance to the 160 dB 
isopleth to the area of 6 survey tracklines),
     the number of potential survey days (160).
    This equation provides the number of instances of take that will 
occur in the duration of the survey, but overestimates the number of 
individual animals taken because not every exposure on every successive 
day is expected to be a new individual. Especially with resident 
species, re-

[[Page 29185]]

exposures of individuals are expected across the months of the survey.
    SAE anticipates that a crew will collect seismic data for 8-10 
hours per day over approximately 160 days over the course of 8 to 9 
months each year. It is assumed that over the course of these 160 days, 
no more than 777 km\2\ will be surveyed in total, but areas can be 
surveyed more than once. It is important to note that environmental 
conditions (such as ice, wind, fog) will play a significant role in the 
actual operating days; therefore, these estimates are conservative in 
order to provide a basis for probability of encountering these marine 
mammal species in the project area.

Summary of Level B Harassment Takes

    Table 4 outlines the density estimates used to estimate Level B 
harassment takes, the requested Level B harassment take levels, the 
abundance of each species in Cook Inlet, the percentage of each species 
or stock estimated to be taken, and current population trends.

Table 4--Density Estimates, Level B Harassment Take Levels, Species or Stock Abundance, Percentage of Population
                                      To Be Taken, and Species Trend Status
----------------------------------------------------------------------------------------------------------------
                               Average density
           Species              (#individuals/   Level B take      Abundance      Percentage of       Trend
                                    km\2\)                                         population
----------------------------------------------------------------------------------------------------------------
Beluga whale.................  Upper=0.0212;                30  312............             9.6  Decreasing.
                                Lower=0.0056.
Humpback whale...............  0.0024.........               5  7,469..........           0.067  Southeast
                                                                                                  Alaska
                                                                                                  increasing.
Minke whale..................  1.14E-05.......               1  1,233..........            0.06  No reliable
                                                                                                  information.
Gray whale...................  5.33E-05.......               7  19,126.........           0.033  Stable/
                                                                                                  increasing.
Killer whale.................  0.00082........              55  2,347                      2.34  Resident stock
                                                                 (resident).               15.9   possibly
                                                                345 (transient)                   increasing.
                                                                                                 Transient stock
                                                                                                  stable.
Harbor porpoise..............  0.0033.........             219  31,046.........            0.70  No reliable
                                                                                                  information.
Dall's porpoise..............  0.0002.........              14  83,400.........           0.016  No reliable
                                                                                                  information.
Harbor seal..................  0.28...........           5,725  22,900.........              25  Stable.
Steller sea lion.............  0.0082.........              25  45,649.........           0.055  Decreasing but
                                                                                                  with regional
                                                                                                  variability
                                                                                                  (some stable
                                                                                                  or
                                                                                                  increasing).
----------------------------------------------------------------------------------------------------------------

Analyses and Determinations

Negligible Impact Analysis

    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). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment 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, feeding, 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, the discussion of our analyses applies to all 
the species listed in Table 4, divided in some places by group, given 
than the anticipated effects of the seismic survey on marine mammals 
are expected to be relatively similar in nature. Where there is 
information about the size, status, or structure of any species or 
stock that would lead to a different analysus (e.g. beluga whales), 
species-specific factors have been identified. In some cases however, 
we add species-specific information regarding effects (including on 
habitat) that also informed our analysis.
    Given the required mitigation and related monitoring, no injuries 
or mortalities are anticipated to occur as a result of SAE's seismic 
survey in Cook Inlet, and none are authorized. Additionally, animals in 
the area are not expected to incur hearing impairment (i.e., TTS or 
PTS) or non-auditory physiological effects. The number of takes that 
are authorized are expected to be limited to short-term Level B 
behavioral harassment. The seismic airguns do not operate continuously 
over a 24-hour period. Rather airguns are operational for a few hours 
at a time totaling about 10 hours a day.
    The addition of nine vessels, and noise due to vessel operations 
associated with the seismic survey, is not outside the present 
experience of marine mammals in Cook Inlet, although levels may 
increase locally. Given the large number of vessels in Cook Inlet and 
the apparent habituation to vessels by Cook Inlet beluga whales and the 
other marine mammals that may occur in the area, vessel activity and 
noise is not expected to have effects that could cause significant or 
long-term consequences for individual marine mammals or their 
populations.
    Cook Inlet beluga whales, the western DPS of Steller sea lions, and 
Central North Pacific humpback whales are listed as endangered under 
the ESA. These stocks are 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. Steller sea lion trends for the western 
stock are variable throughout the region with some decreasing and 
others remaining stable or even indicating slight increases. The 
Central North Pacific population of humpbacks is known to be 
increasing, with different techniques predicting abundance increases 
between 4.9 to 7 percent annually. The other seven species that may be 
taken by harassment during SAE's seismic survey program are not listed 
as threatened or endangered under the ESA nor as depleted under the 
MMPA.
    Cetaceans. Odontocete (including Cook Inlet beluga whales, killer 
whales, and harbor porpoises) reactions to seismic energy pulses are 
usually thought 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. 
Belugas in the Canadian Beaufort Sea in summer appear to be

[[Page 29186]]

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, 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 will likely occur in small numbers in the 
majority of SAE's survey area during the majority of SAE's annual 
operational timeframe of April through December. For the same reason, 
as well as mitigation measures, it is unlikely that animals will be 
exposed to received levels capable of causing injury.
    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 
will 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''. 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.
    In addition, of specific importance to belugas, NMFS seasonally 
restricts seismic 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 proposes to implement a 16 km (10 mi) seasonal 
exclusion from seismic 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. 
Additionally, in the event that a beluga is seen outside of the 
seasonal restricted area and buffer, seismic operations are required to 
shut down if a beluga is seen anywhere in the 160dB disturbance zone.
    Mitigation measures such as controlled vessel speed, dedicated 
marine mammal observers, speed and course alterations, and shutdowns or 
power downs when marine mammals are seen within defined ranges designed 
both to avoid injury and disturbance will further reduce short-term 
reactions and minimize any effects on hearing sensitivity. In all 
cases, the effects of the seismic survey are expected to be short-term, 
with no lasting biological consequence. Therefore, the exposure of 
cetaceans to SAE's seismic survey activity, operation is not 
anticipated to have an adverse effect on annual rates of recruitment or 
survival of the affected species or stocks of cetaceans, and therefore 
will have a negligible impact on them.
    Pinnipeds (harbor seals, Steller sea lions). Some individual 
pinnipeds may be exposed to sound from the seismic surveys more than 
once during the timeframe of the project. Taking into account the 
mitigation measures that are planned, effects on pinnipeds are 
generally expected to be restricted to avoidance of a limited area 
around the survey operation and short-term changes in behavior, falling 
within the MMPA definition of ``Level B harassment.'' Animals are not 
expected to permanently abandon 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 pinniped 
habitat will be affected at any time, and other areas within Cook Inlet 
will be available for necessary biological functions. In addition, the 
area where the survey will take place is not known to be an important 
location where pinnipeds haul out. The closest known haul-out site is 
located on Kalgin Island, which is about 22 km from the McArther River. 
More recently, some large congregations of harbor seals have been 
observed hauling out in upper Cook Inlet. However, mitigation measures, 
such as vessel speed, course alteration, and visual monitoring, and 
restrictions will be implemented to help reduce impacts to the animals. 
Therefore, the exposure of pinnipeds to sounds produced by this phase 
of SAE's seismic survey is not anticipated to have an adverse effect on 
annual rates of recruitment or survival on those pinniped species or 
stocks, and therefore will have a negligible impact.
    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 monitoring and mitigation 
measures, NMFS finds that SAE's seismic survey will have a negligible 
impact on the affected marine mammal species or stocks.

Small Numbers Analysis

    The requested takes authorized annually represent 9.6 percent of 
the Cook Inlet beluga whale population of approximately 312 animals 
(Allen and Angliss, 2014), 2.34 percent of the Alaska resident stock 
and 15.9 percent of the Gulf of Alaska, Aleutian Island and Bering Sea 
stock of killer whales (1,123 residents and 345 transients), 0.70 
percent of the Gulf of Alaska stock of approximately 31,046 harbor 
porpoises, 0.067 percent of the 7,469 Central North Pacific humpback 
whales, 0.06 percent of the 1,233 Alaska minke whales, 0.016 percent of 
the 83,400 Gulf of Alaska Dall's porpoise, and 0.033 percent of the 
eastern North Pacific stock of approximately 19,126 gray whales. The 
take requests presented for harbor seals represent 25 percent of the 
Cook Inlet/Shelikof stock of approximately 22,900 animals. The 
requested takes for Steller sea lions represent 0.055 percent of the 
U.S. portion of the western stock of approximately 45,649 animals. 
These take estimates represent the percentage of each species or stock 
that could be taken by Level B behavioral harassment.
    NMFS finds that any incidental take reasonably likely to result 
from the effects of the activity, as authorized to be mitigated through 
this IHA, will be limited to small numbers relative to the affected 
species or stocks. 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 will be accessible to impacts from SAE'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 and 
Steller sea lions are not common in the seismic survey area; (3) the 
mitigation requirements, which provide spatio-temporal

[[Page 29187]]

limitations that avoid impacts to large numbers of belugas feeding and 
calving in the Susitna Delta and limit exposures to sound levels 
associated with Level B harassment; (4) the monitoring requirements and 
mitigation measures described earlier in this document for all marine 
mammal species that will further 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 River. 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. 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 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 seismic survey. Marine mammals could be behaviorally 
harassed and either become more difficult to hunt or temporarily 
abandon traditional hunting grounds. The other anthropogenic activities 
proposed for Cook Inlet in the 2015 open water season that require an 
Authorization are spread throughout the Inlet and not concentrated in 
the area of SAE's activity, lessening the concern about spatial 
overlap. However, the seismic 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

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a Plan of 
Cooperation or information that identifies what measures have been 
taken and/or will be taken to minimize adverse effects on the 
availability of marine mammals for subsistence purposes. 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. There are several villages in SAE's 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

[[Page 29188]]

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 SAE's seismic 
survey area.
    Villages in lower Cook Inlet adjacent to SAE's seismic area (Kenai, 
Salamatof, and Ninilchik) have either not traditionally hunted beluga 
whales, or at least not in recent years, and rarely do they harvest sea 
lions. Between 1992 and 2008, the only reported sea lion harvests from 
this area were two Steller sea lions taken by hunters from Kenai (Wolfe 
et al. 2009). 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 (or 
outside SAE's lower Cook unit). Although marine mammals remain an 
important subsistence resource in Cook Inlet, the number of animals 
annually harvested are 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 SAE's seismic areas such as the 
Susitna Delta or the west side of lower Cook Inlet. Also, SAE is 
unlikely to conduct seismic activity in the vicinity of any of the 
river mouths where large numbers of seals haul out.
    SAE has identified the following features that are intended to 
reduce impacts to subsistence users:
     In-water seismic activities will follow mitigation 
procedures to minimize effects on the behavior of marine mammals and, 
therefore, opportunities for harvest by Alaska Native communities.
    SAE and NMFS recognize the importance of ensuring that ANOs and 
federally recognized tribes are informed, engaged, and involved during 
the permitting process and will continue to work with the ANOs and 
tribes to discuss operations and activities.
    From mid-March through April 2015, SAE met with the following 
communities and organizations: Nikiski, Ninilchik Native Association 
Inc., Tyonek Native Corporation, Tyonek Village, Ninilchik, Nikiski 
Facilities Group, and United Cook Inlet Drift Association. These 
meetings were meant to inform the audience about the project as well as 
listen to concerns and comments. There will also be a review of permit 
stipulations and a permit matrix developed for the crews. The means of 
communications and contacts list is developed and implemented into the 
project, found in SAE's Plan of Cooperation. The use of PSOs/MMO's on 
board the vessels will ensure that appropriate precautions are taken to 
avoid harassment of marine mammals. 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. If avoidance is not possible, the project manager will 
initiate communication with the Operations Supervisor to resolve the 
issue and plan an alternative course of action. The communications will 
involve the Permits Manager and the Anchorage Office of SAE.

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 
seismic survey area is not an important native subsistence site for 
other subsistence species of marine mammals, and Cook Inlet contains a 
relatively small proportion of marine mammals utilizing Cook Inlet; 
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 SAE's project, but because this subsistence hunt is 
conducted opportunistically and at such a low level (NMFS, 2013c), 
SAE's program is not expected to have an impact on the subsistence use 
of harbor seals. Moreover, the survey will result in only temporary 
disturbances. Accordingly, the specified activity will not impact the 
availability of these other marine mammal species for subsistence uses.
    NMFS anticipates that any effects from SAE's seismic survey on 
marine mammals, especially harbor seals and Cook Inlet beluga whales, 
which are or have been taken for subsistence uses, will 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 SAE's activities.

Endangered Species Act (ESA)

    There are three marine mammal species listed as endangered under 
the ESA with confirmed or possible occurrence in the project area: The 
Cook Inlet beluga whale, the western DPS of Steller sea lion, and the 
Central North Pacific humpback 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 May 7, 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, Central North Pacific 
humpback whales, or western distinct population segment of Steller sea 
lions 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, humpback whales, and Steller sea 
lions. The ITS contains reasonable and prudent measures implemented by 
the terms and conditions to minimize the effect of this take.

[[Page 29189]]

National Environmental Policy Act (NEPA)

    NMFS prepared an EA that includes an analysis of potential 
environmental effects associated with NMFS' issuance of an IHA to SAE 
to take marine mammals incidental to conducting a 3D seismic survey 
program in Cook Inlet, Alaska. NMFS has finalized the EA and prepared a 
FONSI for this action. Therefore, preparation of an Environmental 
Impact Statement is not necessary.

Authorization

    As a result of these determinations, NMFS has issued an IHA to SAE 
for the take of marine mammals incidental to conducting a seismic 
survey program in Cook Inlet, Alaska, from May 13, 2015 through May 12, 
2016, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated.

    Dated: May 12, 2015.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2015-12091 Filed 5-19-15; 8:45 am]
 BILLING CODE 3510-22-P