[Federal Register Volume 76, Number 183 (Wednesday, September 21, 2011)]
[Notices]
[Pages 58473-58487]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-24241]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XA691


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

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS received an application from Apache Alaska Corporation 
(Apache) for an Incidental Harassment Authorization (IHA) to take 
marine mammals, by harassment, incidental to a proposed 3D seismic 
survey in Cook Inlet, Alaska, between November 2011 and November 2012. 
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS requests 
comments on its proposal to issue an IHA to Apache to take, by Level B 
harassment only, five species of marine mammals during the specified 
activity.

DATES: Comments and information must be received no later than October 
21, 2011.

ADDRESSES: Comments on the application should be addressed to Michael 
Payne, Chief, Permits, Conservation and Education Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910. The mailbox address for providing e-
mail comments is [email protected]. NMFS is not responsible for e-
mail comments sent to addresses other than the one provided here. 
Comments sent via e-mail, including all attachments, must not exceed a 
10-megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information 
(for example, name, address, etc.) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    A copy of the application used in this document may be obtained by 
writing to the address specified above, telephoning the contact listed 
below (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited 
in this notice may also be viewed, by appointment, during regular 
business hours, at the aforementioned address.

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

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to 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.
    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.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as:

any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild [``Level A harassment'']; or (ii) has the potential to disturb 
a marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, breeding, feeding, or sheltering 
[``Level B harassment''].

Summary of Request

    NMFS received an application on June 15, 2011, from Apache for the 
taking, by harassment, of marine mammals incidental to a 3D seismic 
survey program in Cook Inlet, Alaska. After addressing comments from 
NMFS, Apache modified its application and submitted a revised 
application on July 19, 2011. The July 19, 2011, application is the one 
available for public comment (see ADDRESSES) and considered by NMFS for 
this proposed IHA.
    The proposed 3D seismic surveys would employ the use of two source 
vessels. Each source vessel will be equipped with compressors and 2400 
in\3\ air gun arrays, as well as additional lower-powered and higher 
frequency survey equipment for collecting bathymetric and shallow sub-
bottom data. In addition, one source vessel will be equipped with a 440 
in\3\ shallow water air gun array, which it can deploy at high tide in 
the intertidal area in less than 1.8 m of water. The proposed survey 
will take place on Apache's leases in Cook Inlet, and during the first 
year Apache anticipates completing ~829 km\2\ of seismic acquisition 
along the west coast of Cook Inlet from the McArthur River up and to 
the south of the Beluga river, in water depths of 0-128 m (0-420 ft).
    Apache intends to conduct offshore/transition (intertidal) zone 
marine surveys during November and December 2011 and March 2012. 
Nearshore areas adjacent to uplands and offshore areas will be acquired 
in open water periods

[[Page 58474]]

between April and September 2012. Impacts to marine mammals may occur 
from noise produced from active acoustic sources (primarily air guns) 
used in the surveys.

Description of the Specified Activity

    In 2010, Apache acquired over 300,000 acres of oil and gas leases 
in Cook Inlet with the primary objective to explore for and develop oil 
fields. In the spring of 2011, Apache conducted a seismic test program 
to evaluate the feasibility of using new nodal (i.e., no cables) 
technology seismic recording equipment for operations in the Cook Inlet 
environment and to test various seismic acquisition parameters to 
finalize the design for a 3D seismic program in Cook Inlet. The test 
program took place in late March 2011 and results indicated that the 
nodal technology was feasible in the Cook Inlet environment. Apache 
proposes to conduct a phased 3D seismic survey program throughout Cook 
Inlet over the course of the next three to five years. The first area 
proposed to be surveyed--and the subject of this proposed IHA--is 
located along the western coast of upper Cook Inlet.
    The proposed operations will be performed from multiple vessels. 
Apache will employ the use of two source vessels. Each source vessel 
will be equipped with compressors and 2400 in\3\ air gun arrays. In 
addition, one source vessel will be equipped with a 440 in\3\ shallow 
water air gun array, which it can deploy at high tide in the intertidal 
area in less than 1.8 m of water. Three shallow draft vessels will 
support cable/nodal deployment and retrieval operations, and one 
mitigation/chase vessel will be used, which will also provide berthing 
for the Protected Species Observers (PSOs). Finally, two smaller jet 
boats will be used for personnel transport and node support in the 
extremely shallow water of the intertidal area. For additional 
information, such as vessel specifications, see Apache's application.
    The actual survey duration to acquire ~829 km\2\ will take 
approximately 160 days to complete over the course of 8-9 months. 
Apache anticipates conducting survey operations 24 hours per day. 
During each 24 hour period, seismic operations will be active; however, 
in-water air guns will only be used for approximately 2.5 hours during 
each of the slack tide periods. There are approximately four slack tide 
periods in a 24-hour day, therefore, air gun operations will be active 
during approximately 10-12 hours per day, if weather conditions allow.

3D Seismic Surveys

    Seismic surveys are designed to collect bathymetric and sub-
seafloor data that allow the evaluation of potential shallow faults, 
gas zones, and archeological features at prospective exploration 
drilling locations. Data are typically collected using multiple types 
of acoustic equipment. During the surveys, Apache proposes to use the 
following in-water acoustic sources: two 2400 in\3\ air gun arrays; a 
single 440 in\3\ air gun array; a 10 in\3\ air gun; a Scout Ultra-Short 
Baseline (USBL) Transceiver; and a Lightweight Release (LR) USBL 
Transponder. In addition, Apache plans to detonate 4 kg of Orica OSX 
Pentolite explosives onshore to acquire data. Except for the 
explosives, the operating frequencies and estimated source levels of 
the survey equipment are provided below.
(1) Airguns
    The 2400 in\3\ air gun arrays and the 440 in\3\ air gun array will 
be used to obtain geological data during the survey. The acoustic 
source level of the 2400 in\3\ air gun array was predicted using an air 
gun array source model (AASM) developed by JASCO. The AASM simulates 
the expansion and oscillation of the air bubbles generated by each air 
gun within a seismic array, taking into account pressure interaction 
effects between bubbles from different air guns. It includes effects 
from surface-reflected pressure waves, heat transfer from the bubbles 
to the surrounding water, and the movements of bubbles due to their 
buoyancy. The model outputs high-resolution air gun pressure signatures 
for each air gun, which are superimposed with the appropriate time 
delays to yield the overall array source signature in any direction. 
The 190, 180, and 160 dBrms re 1 [mu]Pa isopleths were 
estimated at three different water depths (5 m, 25 m, and 45 m) for 
nearshore surveys and at 80 m for channel surveys. The distances to 
these thresholds for the nearshore survey locations are provided in 
Table 1 and correspond to the three transects modeled at each site in 
the onshore, nearshore, and parallel to shore directions. The distances 
to the thresholds for the channel survey locations are provided in 
Table 2 and correspond to the broadside and endfire directions. The 
areas ensonified to the 160 dB isopleth for the nearshore survey are 
provided in Table 3. The area ensonifed to the 160 dB isopleth for the 
channel survey is 389 km\2\.

                        Table 1--Distances to Sound Thresholds for the Nearshore Surveys
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                                    Water depth at      Distance in the     Distance in the     Distance in the
  Threshold (dB re 1 [micro]Pa)     source location    onshore direction  offshore direction   parallel to shore
                                          (m)                (km)                (km)            direction (km
----------------------------------------------------------------------------------------------------------------
160.............................                   5                0.85                3.91                1.48
                                                  25                4.70                6.41                6.34
                                                  45                5.57                4.91                6.10
180.............................                   5                0.46                0.60                0.54
                                                  25                1.06                1.07                1.42
                                                  45                0.70                0.83                0.89
190.............................                   5                0.28                0.33                0.33
                                                  25                0.35                0.36                0.44
                                                  45                0.10                0.10                0.51
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                          Table 2--Distance to Sound Thresholds for the Channel Surveys
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                                                        Water depth at      Distance in the     Distance in the
            Threshold (dB re 1 [micro]Pa)               source location        broadside       endfire direction
                                                              (m)           direction (km)           (km)
----------------------------------------------------------------------------------------------------------------
160.................................................                  80                4.24                4.89

[[Page 58475]]

 
180.................................................                  80                0.91                0.98
190.................................................                  80                0.15                0.18
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        Table 3--Areas Ensonified to 160 dB for Nearshore Surveys
------------------------------------------------------------------------
      Nearshore survey depth                           Area ensonifed to
          classification             Depth range (m)     160 dB (km\2\)
------------------------------------------------------------------------
Shallow...........................               5-21                346
Mid-Depth.........................              21-38                458
Deep..............................              38-54                455
------------------------------------------------------------------------

(2) Pingers
    These instruments will be operated during survey operations to 
determine the exact position of the nodes after they have been placed 
on the seafloor. One device, the Scout Ultra-Short Baseline 
Transceiver, operates at frequencies between 33 and 55 kHz with a 
source level of 188 dB re 1 [mu]Pa at 1 m. The other device, an LR 
Ultra-Short Baseline Transponder, operates at a frequency of 35-50 kHz 
at a source level of 185 dB re 1 [mu]Pa at 1 m. With respect to these 
two sources, Apache provided and NMFS will rely on the distances to the 
Level B harassment thresholds estimated for the ``louder'' of the two; 
therefore, assuming a simple spreading loss of 20 log R (where R is 
radius), with a source level of 188 dB the distance to the 190, 180, 
and 160 dB isopleths would be 1, 3, and 25 m, respectively. Another 
technique for locating the nodes in deeper water is called Ocean Bottom 
Receiver Location, which uses a small volume air gun (10 in\3\) firing 
parallel to the node line.
(3) Detonations of Explosives
    The onshore areas will be surveyed using explosives as the sound 
source. Seismic surveys on land use ``shot holes'' that are drilled 
every 50 m along source lines and are oriented perpendicular to the 
receiver lines and parallel to the coast. At each source location, 
Apache will drill to the prescribed hole depth of approximately 10 m 
and load it with 4 kg of explosives. The hole is then capped with a 
``smart cap'' that makes it impossible to detonate the explosive 
without the proper detonator. During the 2D test program conducted in 
March 2011, Apache deployed acoustic recorders to measure underwater 
sound produced by land-based explosives; however, the resulting 
measurements were inconclusive and Apache has proposed a sound source 
verification study to characterize the underwater received sound levels 
and determine if marine mammal monitoring will be required for future 
onshore operations.
    Apache successfully measured the sounds produced by the air guns 
and pingers during the 2D test program conducted in March 2011 and 
found levels to be consistent with the modeled mitigation threshold 
levels (180 dB for cetaceans, 190 dB for pinnipeds); therefore, except 
for the measurements of in-water sound produced by detonations of 
explosives on shore, a sound source verification study will not be 
included in the proposed 3D seismic survey.

Description of Marine Mammals in the Area of the Specified Activity

    The marine mammal species under NMFS's jurisdiction that could 
occur near operations in Cook Inlet include three cetacean species: 
beluga whale (Delphinapterus leucas), killer whale (Orcinus orca), and 
harbor porpoise (Phocoena phocoena), and two pinniped species: harbor 
seal (Phoca vitulina richardsi) and Steller sea lions (Eumetopias 
jubatus). The marine mammal species that is likely to be encountered 
most widely (in space and time) throughout the period of the planned 
surveys is the harbor seal.
    The Cook Inlet beluga whale and western population of Steller sea 
lion are listed as ``endangered'' under the Endangered Species Act 
(ESA) and as depleted under the MMPA. The site of the proposed survey 
is within designated critical habitat for Cook Inlet beluga whales.
    Apache's application contains information on the status, 
distribution, seasonal distribution, and abundance of each of the 
species under NMFS jurisdiction mentioned in this document. Please 
refer to the application for that information (see ADDRESSES). 
Additional information can also be found in the NMFS Stock Assessment 
Reports (SAR). The Alaska 2010 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2010.pdf.

Potential Effects of the Specified Activity on Marine Mammals

    Operating active acoustic sources, such as air gun arrays, has the 
potential for adverse effects on marine mammals.

Potential Effects of Air Gun Sounds on Marine Mammals

    The effects of sounds from air gun 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, 
and can be categorized as follows (based on Richardson et al. 1995):
(1) 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. 
Although various toothed whales, and (less frequently) pinnipeds have 
been shown to react behaviorally to air gun pulses under some 
conditions, at other times, mammals of both types have shown no overt 
reactions. In general, pinnipeds and

[[Page 58476]]

small odontocetes seem to be more tolerant of exposure to air gun 
pulses than baleen whales.
(2) Behavioral Disturbance
    Marine mammals may behaviorally react to sound 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, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification have the potential to be biologically significant if the 
change affects growth, survival, and reproduction. Examples of 
significant behavioral modifications include:
     Drastic change in diving/surfacing patterns (such as those 
thought to be causing beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cease feeding or social interaction.
    For example, at the Guerreo Negro Lagoon in Baja California, 
Mexico, which is one of the important breeding grounds for Pacific gray 
whales, shipping and dredging associated with a salt works may have 
induced gray whales to abandon the area through most of the 1960s 
(Bryant et al. 1984). After these activities stopped, the lagoon was 
reoccupied, first by single whales and later by cow-calf pairs.
    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).
    Currently NMFS uses a received level of 160 dB re 1 [mu]Pa for 
impulse noises (such as air gun pulses) as the onset threshold for 
marine mammal behavioral harassment.
(3) Masking
    Chronic exposure to excessive, though not high-intensity, noise 
could cause masking at particular frequencies for marine mammals that 
utilize sound for vital biological functions. Masking can interfere 
with detection of acoustic signals such as communication calls, 
echolocation sounds, and environmental sounds important to marine 
mammals. Since marine mammals depend on acoustic cues for vital 
biological functions, such as orientation, communication, finding prey, 
and avoiding predators, marine mammals that experience severe acoustic 
masking (e.g., of a high-intensity level over a long period of time 
throughout a biologically important behavior) could experience 
biologically significant effects that could potentially adversely 
impact survival or reproductive success.
    Masking occurs when noise and signals (that the animal utilizes) 
overlap at both spectral and temporal scales. For the air gun noise 
generated from the proposed seismic surveys, noise will consist of low 
frequency (under 500 Hz) pulses with extremely short durations (less 
than one second). Lower frequency man-made noises are more likely to 
affect detection of communication calls and other potentially important 
natural sounds such as surf and prey noise. There is little concern 
regarding masking near the noise 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 air gun pulses can be ``stretched'' to seconds with long 
decays (Madsen et al. 2006), although the intensity of the noise 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 
are 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 el al. 2000).
(4) Hearing Impairment
    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift (TS), which is 
the loss of hearing sensitivity at certain frequency ranges (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be 
permanent (PTS), in which case the loss of hearing sensitivity is 
unrecoverable, or temporary (TTS), in which case the animal's hearing 
threshold will recover over time (Southall et al. 2007). Just like 
masking, marine mammals that suffer from PTS or TTS will have reduced 
fitness in survival and reproduction, either permanently or 
temporarily. Repeated noise exposure that leads to TTS could cause PTS. 
For transient sounds, the sound level necessary to cause TTS is 
inversely related to the duration of the sound.
    Experiments on a bottlenose dolphin (Tursiops truncatus) and beluga 
whale showed that exposure to a single water gun impulse at a received 
level of 207 kPa (or 30 psi) peak-to-peak (p-p), which is equivalent to 
228 dB re 1 [mu]Pa (p-p), resulted in a 7 and 6 dB TTS in the beluga 
whale at 0.4 and 30 kHz, respectively. Thresholds returned to within 2 
dB of the pre-exposure level within 4 minutes of the exposure (Finneran 
et al. 2002). No TTS was observed in the bottlenose dolphin. Although 
the source level of pile driving from one hammer strike is expected to 
be much lower than the single water gun impulse cited here, animals 
being exposed for a prolonged period to repeated hammer strikes could 
receive more noise exposure in terms of SEL than from the single water 
gun impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the 
aforementioned experiment (Finneran et al. 2002).
    In pinnipeds, TTS thresholds associated with exposure to brief 
pulses (single or multiple) of underwater sound have not been measured. 
Initial evidence from prolonged exposures suggested that some pinnipeds 
may incur TTS at somewhat lower received levels than do small 
odontocetes exposed for similar durations (Kastak et al. 1999, 2005; 
Ketten et al. 2001). However, more recent indications are that TTS 
onset in the most sensitive pinniped species studied (harbor seal, 
which is closely related to the ringed seal) may occur at a similar SEL 
as in odontocetes (Kastak et al., 2004).
    NMFS (1995, 2000) concluded that cetaceans and pinnipeds should not 
be exposed to pulsed underwater noise at received levels exceeding 180 
and 190 dB re 1 [mu]Pa rms, respectively. The

[[Page 58477]]

established 180- and 190-dB re 1 [mu]Pa rms criteria are not considered 
to be the levels above which TTS might occur. Rather, they are the 
received levels above which, in the view of a panel of bioacoustics 
specialists convened by NMFS before TTS measurements for marine mammals 
started to become available, one could not be certain that there would 
be no injurious effects, auditory or otherwise, to marine mammals. As 
summarized above, data that are now available imply that TTS is 
unlikely to occur unless bow-riding odontocetes are exposed to air gun 
pulses much stronger than 180 dB re 1 [micro]Pa rms (Southall et al. 
2007).
    No cases of TTS are expected as a result of Apache's proposed 
activities given the strong likelihood that marine mammals would avoid 
the approaching air guns (or vessel) before being exposed to levels 
high enough for there to be any possibility of TTS, and the mitigation 
measures proposed to be implemented during the survey described later 
in this document.
    There is no empirical evidence that exposure to pulses of air gun 
sound can cause PTS in any marine mammal, even with large arrays of air 
guns (see Southall et al., 2007). However, given the possibility that 
mammals close to an air gun array might incur TTS, there has been 
further speculation about the possibility that some individuals 
occurring very close to air guns might incur PTS. Single or occasional 
occurrences of mild TTS are not indicative of permanent auditory damage 
in terrestrial mammals. Relationships between TTS and PTS thresholds 
have not been studied in marine mammals, but are assumed to be similar 
to those in humans and other terrestrial mammals. That is, PTS might 
occur at a received sound level magnitudes higher than the level of 
onset TTS, or by repeated exposure to the levels that cause TTS. 
Therefore, by means of preventing the onset of TTS, it is highly 
unlikely that marine mammals could receive sounds strong enough (and 
over a sufficient duration) to cause permanent hearing impairment 
during the proposed marine surveys in Cook Inlet.
(5) 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. However, there is no definitive evidence that any of these 
effects occur even for marine mammals in close proximity to large 
arrays of air guns, and beaked whales do not occur in the proposed 
project area. In addition, marine mammals that show behavioral 
avoidance of seismic vessels, including most baleen whales, some 
odontocetes (including belugas), and some pinnipeds, are especially 
unlikely to incur non-auditory impairment or other physical effects. 
The distances to the 180 and 190 dB thresholds for the air gun array 
proposed to be used by Apache are provided above in Tables 1 and 2.
    Therefore, it is unlikely that such effects would occur during 
Apache's proposed surveys given the brief duration of exposure and the 
planned monitoring and mitigation measures described later in this 
document.
(6) 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). Air 
gun pulses are less energetic and their peak amplitudes have slower 
rise times. To date, there is no evidence that serious injury, death, 
or stranding by marine mammals can occur from exposure to air gun 
pulses, even in the case of large air gun arrays.
    However, in numerous past IHA notices for seismic surveys, 
commenters have referenced two stranding events allegedly associated 
with seismic activities, one off Baja California and a second off 
Brazil. NMFS has addressed this concern several times, and, without new 
information, does not believe that this issue warrants further 
discussion. For information relevant to strandings of marine mammals, 
readers are encouraged to review NMFS' response to comments on this 
matter found in 69 FR 74905 (December 14, 2004), 71 FR 43112 (July 31, 
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 
2006). In addition, a May-June 2008, stranding of 100-200 melon-headed 
whales (Peponocephala electra) off Madagascar that appears to be 
associated with seismic surveys is currently under investigation (IWC 
2009).
    It should be noted that strandings related to sound exposure have 
not been recorded for marine mammal species in Cook Inlet. NMFS notes 
that beluga whale strandings in Cook Inlet are not uncommon; however, 
these events often coincide with extreme tidal fluctuations (``spring 
tides'') or killer whale sightings (Shelden et al., 2003). No 
strandings or marine mammals in distress were observed during the 2D 
test survey conducted by Apache in March 2011 and none were reported by 
Cook Inlet inhabitants. As a result, NMFS does not expect any marine 
mammals will incur serious injury or mortality in Cook Inlet or strand 
as a result of the proposed seismic survey.

Potential Effects From Other Sound Sources on Marine Mammals

    Active acoustic sources other than the air gun arrays have been 
proposed for Apache's seismic survey in Cook Inlet. The specifications 
for this equipment (source levels and frequency ranges) are provided 
above. In general, the potential effects of this equipment on marine 
mammals are similar to those from the air gun, except the magnitude of 
the impacts is expected to be much less due to the lower intensity and 
higher frequencies. Estimated source levels from these devices are 
discussed above.

Vessel Sounds

    In addition to the noise generated from seismic air guns and active 
sonar systems, various types of vessels will be used in the operations, 
including source vessels and the vessel used for placing and retrieving 
the nodal recording system. Sounds from boats and vessels have been 
reported extensively (Greene and Moore 1995; Blackwell and Greene 2002; 
2005; 2006). Measurements of underwater vessel sound have been 
performed in upper Cook Inlet. For example, Blackwell and Greene (2002) 
conducted a survey that measured in-water noise from various sources in 
Cook Inlet, including a tug boat docking a barge. The highest SPL 
recorded for the working tug under load was 149 dB re 1 [micro]Pa, at a 
distance of about 90 m, with an extrapolated SPL at 0.9 m of 178.9 dB 
re 1 [micro]Pa. Compared to air gun pulses, underwater sound from 
vessels is generally at relatively low frequencies.
    The primary sources of sounds from all vessel classes are propeller 
cavitation, propeller singing, and propulsion or other machinery. 
Propeller cavitation is usually the dominant noise source for vessels 
(Ross 1976). Propeller cavitation and singing are produced outside the 
hull, whereas propulsion or other machinery noise originates inside the 
hull. There are additional sounds produced by vessel activity, such as 
pumps, generators, flow noise from water passing over the hull, and 
bubbles breaking in the wake.

[[Page 58478]]

Land-Based Explosives

    The onshore component of the seismic survey involves the 
underground detonation of explosive devices to acquire seismic data on 
land. Because underwater sound levels associated with the land-based 
explosives are currently unknown, Apache proposes to conduct a sound 
source verification (SSV) study to ensure that marine mammals are not 
exposed to underwater sound levels that exceed the NMFS injury or 
harassment thresholds. This study is expected to take two days to 
complete and a report will be submitted to NMFS prior to making a final 
determination on whether to issue or deny the IHA. The study will 
include a robust marine mammal monitoring plan to ensure that marine 
mammals are not harassed or injured. For example, Apache proposes to 
conduct visual monitoring using vessel-based and aerial platforms. In 
addition, the SSV will only take place during daylight hours with good 
visibility. Following the completion of the study, a SSV report will be 
submitted to NMFS. The report will describe the operations that were 
conducted and the marine mammals that were observed. The report will 
provide full documentation of the methods, results, and interpretations 
pertaining to all monitoring and will contain information on the need 
to implement marine mammal monitoring during land-based operations.

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 and are discussed below.

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 noise level.
    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.
    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 capeline 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).

Potential Impacts to the Benthic Environment

    Apache'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 will be placed on the seafloor by 
specific vessels in lines parallel to each other with a node line 
spacing of 402 m. Each nodal ``patch'' will have six to eight 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 
air gun 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.
    Based on the preceding discussion, the proposed 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.

Proposed Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses.
    For the proposed seismic survey in Cook Inlet, Apache worked with 
NMFS and proposed the following mitigation measures to minimize the 
potential impacts to marine mammals in the project vicinity as a result 
of the survey activities.

Mitigation Measures Proposed in Apache's IHA Application

    For the proposed mitigation measures, Apache listed the following 
protocols to be implemented during its seismic survey in Cook Inlet.
(1) Operation of Mitigation Air Gun at Night
    Apache proposes to conduct both daytime and nighttime operations. 
Nighttime operations will only be initiated if a mitigation air gun 
(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 during nighttime operations 
because dedicated PSOs will not be on duty and any unseen animals may 
be exposed to injurious levels of sound from the full array. At night, 
the vessel captain and crew will maintain lookout for marine mammals 
and will order the air gun(s) to be shut down if marine mammals are 
observed in or about to enter the safety radii. If a shut-down occurs 
during nighttime operations, seismic survey activity will be suspended 
until the following day and will only be resumed if the full safety 
zone is visible.
 (2) Safety and Disturbance Zones
    Under current NMFS guidelines, ``safety radii'' for marine mammal 
exposure to impulse sources are customarily defined as the distances 
within which received sound levels are >=180 dBrms re 1 
[mu]Pa for cetaceans and >=190 dBrms re 1 [mu]Pa for 
pinnipeds. These

[[Page 58479]]

safety criteria are based on an assumption that SPL received at levels 
lower than these will not injure these animals or impair their hearing 
abilities, but that SPL received at higher levels might have some such 
effects. Disturbance or behavioral effects to marine mammals from 
underwater sound may occur after exposure to sound at distances greater 
than the safety radii (Richardson et al. 1995).
    The proposed surveys will use an air gun sources composed of two 
2400 in\3\ air guns, a single 440 in\3\ air gun, and a single 10 in\3\ 
air gun. Safety and disturbance radii for the sound levels produced by 
the planned airgun configurations have been estimated (Tables 1 and 2) 
and will be used for mitigation purposes during the seismic survey 
activities.
    In addition to the marine mammal monitoring radii described above, 
pursuant to Alaska Department of Fish and Game restrictions, there will 
be a 1.6 km setback of sound source points from the mouths of any 
anadromous streams.
    Apache also plans to use dedicated vessels to deploy and retrieve 
the nodal recording system. Sounds produced by the vessels are not 
expected to exceed 180 dB (rms). Therefore, mitigation related to 
acoustic impacts from these activities is not expected to be necessary.
    An acoustics contractor will perform direct measurements of the 
received levels of underwater sound versus distance and direction from 
the detonation of explosives onshore using calibrated hydrophones. The 
acoustic data will be analyzed as quickly as reasonably practicable in 
the field and used to determine whether the detonation of explosives 
onshore exposes marine mammals to underwater sound levels that may 
result in Level B harassment. The field report will be made available 
to NMFS prior to the final determination on whether to issue or deny 
the IHA. If necessary, mitigation measures similar to those proposed 
for the other sound sources (i.e., establishment of 160, 180, and 190 
dB isopleths with dedicated monitoring and detonation delay procedures) 
will be implemented for this aspect of the seismic survey.
(3) Speed and Course Alterations
    If a marine mammal is detected outside the applicable safety radius 
and, based on its position and the relative motion, is likely to enter 
the safety radius, changes of the vessel's speed and/or direct course 
will be considered if this does not compromise operational safety. For 
marine seismic surveys using large arrays, course alterations are not 
typically possible. However, for the smaller air gun arrays planned 
during the proposed site surveys, such changes may be possible. After 
any such speed and/or course alteration is begun, the marine mammal 
activities and movements relative to the survey vessel will be closely 
monitored to ensure that the marine mammal does not approach within the 
safety radius. If the mammal appears likely to enter the safety radius, 
further mitigative actions will be taken, including a power down or 
shut down of the airgun(s).
(4) Power-Downs
    A power-down for mitigation purposes is the immediate reduction in 
the number of operating airguns such that the radii of the 190 dB rms 
and 180 dB rms zones are decreased to the extent that an observed 
marine mammal(s) are not in the applicable safety zone of the full 
array. During a power-down, one air gun, typically the 10 in\3\, 
continues firing. Operation of the 10 in\3\ air gun decreases the 
safety radii to 10 m, 33 m, and 330 m for the 190 dB, 180 dB, and 160 
dB, respectively. The continued operation of one airgun is intended to 
(a) alert marine mammals to the presence of the survey vessel in the 
area, and (b) retain the option of initiating a ramp up to full 
operations under poor visibility conditions.
    The array will be immediately powered down whenever a marine mammal 
is sighted approaching close to or within the applicable safety zone of 
the full array, but is outside the applicable safety zone of the single 
mitigation airgun. Likewise, if a mammal is already within the safety 
zone when first detected, the airguns will be powered down immediately. 
If a marine mammal is sighted within or about to enter the applicable 
safety zone of the single mitigation airgun, it too will be shut down 
(see following section).
    Following a power-down, operation of the full airgun array will not 
resume until the marine mammal has cleared the safety zone. The animal 
will be considered to have cleared the safety zone if it
     Is visually observed to have left the safety zone of the 
full array, or
     Has not been seen within the zone for 15 min in the case 
of pinnipeds or small odontocetes, or
     Has not been seen within the zone for 30 min in the case 
of large odontocetes.
(5) Shut-Downs
    The operating air gun(s) will be shut down completely if a marine 
mammal approaches or enters the safety radius and a power-down is not 
practical or adequate to reduce exposure to less than 190 or 180 dB 
rms, as appropriate. In most cases, this means the mitigation airgun 
will be shut down completely if a marine mammal approaches or enters 
the estimated safety radius around the single 10 in\3\ air gun while it 
is operating during a power down. Air gun activity will not resume 
until the marine mammal has cleared the safety radius. The animal will 
be considered to have cleared the safety radius as described above 
under power down procedures.
 (6) Ramp Ups
    A ramp up of an air gun 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 air guns 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 proposed seismic survey, the seismic operator will ramp 
up the airgun cluster slowly. Full ramp-ups (i.e., from a cold start 
after a shut-down, when no airguns have been firing) will begin by 
firing a single airgun in the array. The minimum duration of a shut-
down period, i.e., without air guns firing, which must be followed by a 
ramp-up is typically the amount of time it would take the source vessel 
to cover the 180-dB safety radius. Given the size of the planned air 
gun arrays, that period is estimated to be about 1-2 minutes based on 
the modeling results described above and a survey speed of 2-4 kts.
    A full ramp up, after a shut down, will not begin until there has 
been a minimum of 30 minutes of observation of the safety zone by PSOs 
to assure that no marine mammals are present. The entire safety zone 
must be visible during the 30-minute lead-in to a full ramp up. If the 
entire safety zone is not visible, then ramp up from a cold start 
cannot begin. If a marine mammal(s) is sighted within the safety zone 
during the 30-minute watch prior to ramp up, ramp up will be delayed 
until the marine mammal(s) is sighted outside of the safety zone or the 
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for 
small odontocetes and pinnipeds, or 30 minutes for large odontocetes.

[[Page 58480]]

Additional Mitigation Measures Proposed by NMFS

    Besides Apache's proposed mitigation measures discussed above, NMFS 
proposes the following additional protective measures to address some 
uncertainties regarding the impacts of seismic surveys on beluga whale 
cow-calf pairs and aggregations of whales. Specifically, NMFS proposes 
that a 160-dB vessel monitoring zone will be established and monitored 
in Cook Inlet during all seismic surveys. Whenever an aggregation of 
beluga whales, killer whales, or harbor porpoises (five or more whales 
of any age/sex class that appear to be engaged in a non-migratory, 
significant biological behavior (e.g., feeding, socializing)) are 
observed approaching the 160-dB safety zone around the survey 
operations, the survey activity will not commence or will shut down, 
until they are no longer present within the 160-dB safety zone of 
seismic surveying operations.
    Furthermore, NMFS proposes the following measures be included in 
the IHA, if issued, in order to ensure the least practicable impact on 
the affected species or stocks:
    (1) All vessels should reduce speed when within 300 yards (274 m) 
of whales, and those vessels capable of steering around such groups 
should do so. Vessels may not be operated in such a way as to separate 
members of a group of whales from other members of the group;
    (2) Avoid multiple changes in direction and speed when within 300 
yards (274 m) of whales; and
    (3) When weather conditions require, such as when visibility drops, 
support vessels must adjust speed (increase or decrease) and direction 
accordingly to avoid the likelihood of injury to whales.

Mitigation Conclusions

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

Proposed Monitoring and Reporting

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

Monitoring Measures Proposed in Apache's IHA Application

    The monitoring plan proposed by Apache can be found in section 13 
of the IHA application. The plan may be modified or supplemented based 
on comments or new information received from the public during the 
public comment period. A summary of the primary components of the plan 
follows.
(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 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 ``take by harassment'' as defined by NMFS.
    A sufficient number of PSOs 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; (2) 
maximum of 4 consecutive hours on watch per PSO; and (3) maximum of 12 
hours of watch time per day per PSO.
    PSO teams will consist of experienced field biologists. An 
experienced field crew leader will supervise the PSO team onboard the 
survey vessel. Apache currently plans to have PSOs aboard the three 
vessels: the two source vessels (M/V Peregrine Falcon and M/V Arctic 
Wolf) and one support vessel (M/V Dreamcatcher). Two PSOs will be on 
the source vessels and two PSOs will be on the support vessel to 
observe the safety, power down, and shut down areas. When marine 
mammals are about to enter or are sighted within designated safety 
zones, air gun 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 air gun 
or pinger operations after an extended shut down.
    Crew leaders and most other biologists serving as observers will be 
individuals with experience as observers during seismic surveys in 
Alaska or other areas in recent years.
    The observer(s) will watch for marine mammals from the best 
available vantage point on the source and support vessels, typically 
the flying bridge. The observer(s) will scan systematically with the 
unaided eye and 7 x 50 reticle binoculars. Laser range finders will be 
available to assist with estimating distance. Personnel on the bridge 
will assist the observer(s) in watching for marine mammals.
    All observations will be recorded in a standardized format. Data 
will be entered into a custom database using a notebook computer. The 
accuracy of the data will be verified by computerized validity data 
checks as the data are entered and by subsequent manual checks of the 
database. These procedures will allow for initial summaries of the data 
to be prepared during and shortly after the completion of the field 
program, and will facilitate transfer of the data to statistical, 
geographical, or other programs for future processing and achieving. 
When a mammal sighting is made, the following information about the 
sighting will be recorded:
    (A) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from the PSO, apparent reaction to 
activities (e.g., none, avoidance, approach, paralleling, etc.), 
closest point of approach, and behavioral pace;
    (B) Time, location, speed, activity of the vessel, sea state, ice 
cover, visibility, and sun glare; and
    (C) The positions of other vessel(s) in the vicinity of the PSO 
location.

[[Page 58481]]

    The ship's position, speed of support vessels, and water 
temperature, water depth, sea state, ice cover, visibility, and sun 
glare will also be recorded at the start and end of each observation 
watch, every 30 minutes during a watch, and whenever there is a change 
in any of those variables.
(2) Visual Shore-Based Monitoring
    In addition to the vessel-based PSOs, Apache proposes to utilize a 
shore-based station to visually monitor for marine mammals. The shore-
based station will follow all safety procedures, including bear safety. 
The location of the shore-based station will need to be sufficiently 
high to observe marine mammals; the PSOs would be equipped with 
pedestal mounted ``big eye'' (20 x 110) binoculars. The shore-based 
PSOs would scan the area prior to, during, and after the air gun 
operations, and would be in contact with the vessel-based PSOs via 
radio to communicate sightings of marine mammals approaching or within 
the project area.
(3) Aerial-Based Monitoring
    When practicable, Apache proposes to utilize the crew helicopter to 
conduct aerial surveys near river mouths prior to the commencement of 
air gun operations in order to identify locations where beluga whales 
congregate. The helicopter will not be used every day, but will be used 
when survey operations occur near a river mouth. The types of 
helicopters currently planned for use by Apache include a Bell 407, 
Bell UH1B, and ASB3. Weather and scheduling permitting, aerial surveys 
will fly at an altitude of 305 m (1,000 ft). In the event of a marine 
mammal sighting, aircraft will attempt to maintain a radial distance of 
457 m (1,500 ft) from the marine mammal(s). Aircraft will avoid 
approaching marine mammals from head-on, flying over or passing the 
shadow of the aircraft over the marine mammal(s). By following these 
operational requirements, sound levels underwater are not expected to 
meet or exceed NMFS harassment thresholds (Richardson et al., 1995; 
Blackwell et al., 2002).
 (4) Acoustic Monitoring
    To further enhance detection of cetaceans, Apache proposes to 
deploy passive acoustic monitoring (PAM) devices during the seismic 
survey. According to Apache's IHA application, the actual PAM system 
has not been identified; however, Apache anticipates utilizing the same 
system that was deployed during the 2D test program in March 2011 in 
Cook Inlet. Apache expects to deploy two PAM devices that will send 
real-time acoustic data via digital UHF radio-broadcast systems to the 
PAM operators aboard the M/V Dreamcatcher. The PAM operators will use 
specialized real-time detection software and audio playback to detect 
marine mammal sounds. If the PAM operators detect marine mammals, 
Apache will initiate a temporary shut-down of the air gun arrays to 
avoid takes. Following a shut-down, the air guns may be restarted in 
accordance with the ramp-up procedure described earlier.

Reporting Measures

(1) SSV Report on In-Water Noise From Explosives Onshore
    A report on the preliminary results of the acoustic verification 
measurements, including as a minimum the measured 190-, 180-, and 160-
dBrms re 1 [mu]Pa radii of the onshore explosive 
detonations, will be submitted prior to the publication of a Federal 
Register notice announcing the issuance or denial of the IHA. If 
applicable, this report will specify the distances of the safety zones 
that will be adopted and monitored for the marine survey activities.
(2) Field Reports
    During the proposed survey program, the PSOs will prepare a report 
each day or at such other interval as the IHA (if issued), or Apache 
may require, summarizing the recent results of the monitoring program. 
The field reports will summarize the species and numbers of marine 
mammals sighted. These reports will be provided to NMFS and to the 
survey operators.
(3) Technical Report
    The results of Apache's 2011 monitoring program, including 
estimates of ``take'' by harassment, will be presented in the ``90-
day'' and Final Technical reports. The Technical Report will include:
    (a) Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
    (b) Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    (c) Species composition, occurrence, and distribution of marine 
mammal sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), group sizes, and ice cover;
    (d) Analyses of the effects of survey operations;
     Sighting rates of marine mammals during periods with and 
without seismic survey activities (and other variables that could 
affect detectability), such as:
     Initial sighting distances versus survey activity state;
     Closest point of approach versus survey activity state;
     Observed behaviors and types of movements versus survey 
activity state;
     Numbers of sightings/individuals seen versus survey 
activity state;
     Distribution around the source vessels versus survey 
activity state; and
     Estimates of take by harassment.
(4) Comprehensive Report
    Following the survey season, a comprehensive report describing the 
vessel-based, shore-based, aerial-based, and acoustic monitoring 
programs will be prepared. The comprehensive report will describe the 
methods, results, conclusions and limitations of each of the individual 
data sets in detail. The report will also integrate (to the extent 
possible) the studies into a broad based assessment of industry 
activities, and other activities that occur in Cook Inlet, and their 
impacts on marine mammals. The report will help to establish long-term 
data sets that can assist with the evaluation of changes in the Cook 
Inlet ecosystem. The report will attempt to provide a regional 
synthesis of available data on industry activity in this part of Alaska 
that may influence marine mammal density, distribution and behavior.
(5) Notification of Injured or Dead Marine Mammals
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury (Level A harassment), serious injury or 
mortality (e.g., ship-strike, gear interaction, and/or entanglement), 
Apache will immediately cease the specified activities and immediately 
report the incident to the Chief of the Permits, Conservation, and 
Education Division, Office of Protected Resources, NMFS, and the Alaska 
Regional Stranding Coordinators. The report must include the following 
information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;

[[Page 58482]]

     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).

Activities will not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with Apache to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Apache may not resume their 
activities until notified by NMFS via letter, e-mail, or telephone.

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

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment]. Only take by Level B behavioral 
harassment is anticipated as a result of the proposed marine survey 
program. Anticipated impacts to marine mammals are associated with 
noise propagation from the airgun(s) used in the seismic survey; 
however, Level B harassment may also result from the detonation of 
explosives onshore if supported by the proposed SSV study.
    The full suite of potential impacts to marine mammals was described 
in detail in the ``Potential Effects of the Specified Activity on 
Marine Mammals'' section found earlier in this document. The potential 
effects of sound from the proposed seismic survey might include one or 
more of the following: tolerance; masking of natural sounds; behavioral 
disturbance; non-auditory physical effects; and, at least in theory, 
temporary or permanent hearing impairment (Richardson et al. 1995). As 
discussed earlier in this document, the most common impact will likely 
be from behavioral disturbance, including avoidance of the ensonified 
area or changes in speed, direction, and/or diving profile of the 
animal. For reasons discussed previously in this document, hearing 
impairment (TTS and PTS) are highly unlikely to occur based on the 
proposed mitigation and monitoring measures that would preclude marine 
mammals being exposed to noise levels high enough to cause hearing 
impairment.
    For impulse sounds, such as those produced by airgun(s) used in the 
seismic survey, NMFS uses the 160 dBrms re 1 [mu]Pa isopleth 
to indicate the onset of Level B harassment. Apache provided 
calculations for the 160-dB isopleths and then used those isopleths to 
estimate takes by harassment. NMFS used the calculations to make the 
necessary MMPA preliminary findings. Apache provided a full description 
of the methodology used to estimate takes by harassment in its IHA 
application (see ADDRESSES), which is also provided in the following 
sections.
    Apache requests authorization to take five marine mammal species by 
Level B harassment. These five marine mammal species are: Cook Inlet 
beluga whale (Delphinapterus leucas); killer whale (Orcinus orca); 
harbor porpoise (Phocoena phocoena); harbor seal (Phoca vitulina 
richardsi), and Steller sea lion (Eumetopias jubatus).

Basis for Estimating ``Take by Harassment''

    As stated previously, it is current NMFS policy to estimate take by 
Level B harassment for impulse sounds at a received level of 160 
dBrms re 1 [mu]Pa. However, not all animals react to sounds 
at this low level, and many will not show strong reactions (and in some 
cases any reaction) until sounds are much stronger. Southall et al. 
(2007) provide a severity scale for ranking observed behavioral 
responses of both free-ranging marine mammals and laboratory subjects 
to various types of anthropogenic sound (see Table 4 in Southall et al. 
(2007)). Tables 7, 9, and 11 in Southall et al. (2007) outline the 
numbers of low-frequency cetaceans, mid-frequency cetaceans, and 
pinnipeds in water, respectively, reported as having behavioral 
responses to multi-pulses in 10-dB received level increments. These 
tables illustrate that for the studies summarized the more severe 
reactions did not occur until sounds were much higher than 160 
dBrms re 1 [mu]Pa.
    As described earlier in the document, air gun arrays will be used 
to obtain geological data during the surveys. For use in estimating 
potential harassment takes in this application, as well as for 
mitigation radii to be implemented by PSOs, ranges to the 160 
dBrms re 1 [mu]Pa isopleths were estimated at three 
different water depths (5 m, 25 m, and 45 m) for nearshore surveys and 
at 80 m for channel surveys. The distances to this threshold for the 
nearshore survey locations are provided in Table 1 and correspond to 
the three transects modeled at each site in the onshore, nearshore, and 
parallel to shore directions. The distances to the thresholds for the 
channel survey locations are provided in Table 2 and correspond to the 
broadside and endfire directions. The areas ensonified to the 160 dB 
isopleth for the nearshore survey are provided in Table 3. The area 
ensonifed to the 160 dB isopleth for the channel survey is 389 km\2\.
    The following subsections describe the estimated densities of 
marine mammals that may occur in the areas where activities are 
planned, and areas of water that may be ensonified by pulsed sounds to 
>=160 dB.
    Marine mammal densities near the planned activities in Cook Inlet 
were estimated from the annual aerial surveys conducted by NMFS between 
2000 and 2010 for Cook Inlet beluga whales (Rugh et al. 2000, 2001, 
2002, 2003, 2004, 2005, 2006, 2007; Shelden et al. 2008,

[[Page 58483]]

2009, 2010). These surveys are flown in June to collect abundance data 
for beluga whales, but sightings of other marine mammals are also 
reported. Although these data are only collected in one month each 
year, these surveys provide the best available relatively long-term 
data set for sighting information in the proposed action area, but do 
not account for seasonal variations in distribution or habitat use of 
each species. Therefore, the use of these data to estimate density is 
considered to be extremely conservative with respect to the probability 
of observing these animals in the action area. The maximum and average 
densities over the course of the total survey years (2000-2010) are 
provided in Table 4. As discussed below, beluga whales are observed in 
higher concentrations near river mouths, particularly the Susitna 
River, due to feeding. Therefore, to account for the higher 
concentrations near river mouths, the highest number of beluga whales 
observed for each year was used to provide a density for river mouths. 
To account for the lower concentrations away from river mouths, the 
average number of beluga whales observed for each year was used to 
provide a density away from river mouths. A maximum and average density 
are provided to account for the inherent level of uncertainty in using 
aerial surveys conducted for a few days once a year in order to 
estimate density for the entire year. These densities will be used to 
estimate the number of Level B takes incidental to the proposed 
activity.

               Table 4--Summary of Marine Mammal Densities
------------------------------------------------------------------------
                                            Density (number/km \2\)
               Species               -----------------------------------
                                           Maximum           Average
------------------------------------------------------------------------
Beluga whale (average number                   0.00103           0.00026
 observed)..........................
Beluga whale (maximum number                   0.00770           0.00154
 observed--rivers)..................
Harbor seal (total number observed).           0.00776           0.00290
Harbor porpoise (total number                  0.00037           0.00004
 observed)..........................
Killer whale (total number observed)           0.00011           0.00001
Steller sea lion (total number                 0.00035           0.00007
 observed)..........................
------------------------------------------------------------------------

    Fifteen species of marine mammals are known to occur in Cook Inlet, 
but only five of these (Cook Inlet beluga whales, killer whales, harbor 
porpoises, harbor seals, and Steller sea lions) are likely to be 
encountered during the proposed survey activities in the upper inlet. 
Two of the five species (Cook Inlet beluga whales and western 
population of Steller sea lions) are listed as endangered under the 
ESA.
(1) Cetaceans
    Beluga Whales--Cook Inlet beluga whales reside in Cook Inlet year-
round although their distribution and density changes seasonally. 
Factors that are likely to influence beluga whale distribution within 
the inlet include prey availability, predation pressure, sea-ice cover, 
and other environmental factors, reproduction, sex and age class, and 
human activities (Rugh et al., 2000; NMFS 2008). Seasonal movement and 
density patterns as well as site fidelity appear to be closely linked 
to prey availability, coinciding with seasonal salmon and eulachon 
concentrations (Moore et al., 2000). For example, during spring and 
summer, beluga whales are generally concentrated near the warmer waters 
of river mouths where prey availability is high and predator occurrence 
in low (Huntington 2000; Moore et al., 2000). Beluga whales use several 
areas of the upper Cook Inlet for repeated summer and fall feeding. The 
primary hotspots for beluga feeding include the Big and Little Susitna 
rivers, Eagle Bay to Eklutna River, Ivan Slough, Theodore River, Lewis 
River, and Chickaloon River and Bay (NMFS 2008). Availability of prey 
species appears to be the most influential environmental variable 
affecting Cook Inlet beluga whale distribution and relative abundance 
(Moore et al. 2000). The patterns and timing of eulachon and salmon 
runs have a strong influence on beluga whale feeding behavior and their 
seasonal movements (Nemeth et al., 2007; NMFS 2008). The presence of 
prey species may account for the seasonal changes in beluga group size 
and composition (Moore et al., 2000). Aerial and vessel-based 
monitoring conducted by Apache during the March 2011 2D test program in 
Cook Inlet reported 33 beluga sightings. One of the sightings was of a 
large group (~25 individuals on March 27, 2011) of feeding/milling 
belugas near the mouth of the Drift River. Also on March 27, 2011, PSOs 
onboard the M/V Dreamcatcher reported a group of seven beluga whales 
approximately 0.5 nm from the vessel. Land-based PSOs were able to 
observe this group of beluga whales for approximately 2.5 hrs. A single 
beluga whale was observed near the mouth of the Drift River by the 
aerial-based monitors on March 28, 2011, prior to the seismic ramp-up 
period. If belugas are present during the late summer/early fall, they 
are more likely to occur in shallow areas near river mouths in upper 
Cook Inlet. As discussed earlier, expected densities were calculated 
from the annual aerial surveys conducted by NMFS between 2000 and 2010 
(Rugh et al. 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007; Shelden et 
al. 2008, 2009, 2010). Those densities are presented above in Table 4.
    Killer Whales--In general, killer whales are rare in upper Cook 
Inlet, where transient killer whales are known to feed on beluga whales 
and resident killer whales are known to feed on anadromous fish 
(Shelden et al., 2003). The availability of these prey species largely 
determines the likeliest times for killer whales to be in the area. 
Between 1993 and 2004, 23 sightings of killer whales were reported in 
the lower Cook Inlet during aerial surveys by Rugh et al. (2005). 
Surveys conducted over a span of 20 years by Shelden et al. (2003) 
reported 11 sightings in upper Cook Inlet between Turnagain Arm, 
Susitna Flats, and Knik Arm. No killer whales were spotted during 
recent surveys by Funk et al. (2005), Ireland et al. (2005), Brueggeman 
et al. (2007a, 2007b, 2008), or Prevel Ramos et al. (2006, 2008). 
Eleven killer whale strandings have been reported in Turnagain Arm, six 
in May 1991 and five in August 1993. Therefore, very few killer whales, 
if any, are expected to approach or be in the vicinity of the action 
area.
    Harbor Porpoise--The most recent estimated density for harbor 
porpoises in Cook Inlet is 7.2 per 1,000 km\2\ (Dahlheim et al., 2000) 
indicating that only a small number use Cook Inlet. Harbor porpoise 
have been reported in lower Cook Inlet from Cape Douglas to the West 
Foreland, Kachemak Bay, and offshore (Rugh et al., 2005). Small numbers 
of harbor porpoises have been

[[Page 58484]]

consistently reported in upper Cook Inlet between April and October, 
except for a recent survey that recorded higher than usual numbers. 
Prevel Ramos et al. (2008) reported 17 harbor porpoises from spring to 
fall 2006, while other studies reported 14 in the spring of 2007 
(Brueggeman et al. 2007) and 12 in the fall (Brueggeman et al. 2008). 
During the spring and fall of 2007, 129 harbor porpoises were reported 
between Granite Point and the Susitna River; however, the reason for 
the increase in numbers of harbor porpoise in the upper Cook Inlet 
remains unclear and the disparity with the result of past sightings 
suggests that it may be an anomaly. The spike in reported sightings 
occurred in July, which was followed by sightings of 79 harbor 
porpoises in August, 78 in September, and 59 in October, 2007. It is 
important to note that the number of porpoises counted more than once 
was unknown, which suggests that the actual numbers are likely smaller 
than those reported. In addition, recent passive acoustic research in 
Cook Inlet by the Alaska Department of Fish and Game and the National 
Marine Mammal Laboratory have indicated that harbor porpoises occur in 
the area more frequently than previously thought, particularly in the 
West Foreland area in the spring (NMFS 2011); however overall numbers 
are still unknown at this time.
 (2) Pinnipeds
    Two species of pinnipeds may be encountered in Cook Inlet: Harbor 
seal and Steller sea lion.
    Harbor Seals--Harbor seals inhabit the coastal and estuarine waters 
of Cook Inlet. In general, harbor seals are more abundant in lower Cook 
Inlet than in upper Cook Inlet, but they do occur in the upper inlet 
throughout most of the year (Rugh et al. 2005). Harbor seals are non-
migratory; their movements are associated with tides, weather, season, 
food availability, and reproduction. The major haulout sites for harbor 
seals are located in lower Cook Inlet and their presence in the upper 
inlet coincides with seasonal runs of prey species. For example, harbor 
seals are commonly observed along the Susitna River and other 
tributaries along upper Cook Inlet during the eulachon and salmon 
migrations (NMFS 2003). During aerial surveys of upper Cook Inlet in 
2001, 2002, and 2003, harbor seals were observed 24 to 96 km south-
southwest of Anchorage at the Chickaloon, Little Susitna, Susitna, 
Ivan, McArthur, and Beluga Rivers (Rugh et al., 2005). During the 2D 
test program in March 2011, two harbor seals were observed by vessel-
based PSOs. On March 25, 2011, one harbor seal was observed 
approximately 400 m from the M/V Miss Diane. At the time of the 
observation, the vessel was operating the positioning pinger and PSOs 
instructed the operator to implement a shut-down. The pinger was shut 
down for 30 minutes while PSO monitored the area and re-started the 
device when the animal was not sighted again during the 30 minute site 
clearing protocol. No unusual behaviors were reported during the time 
the animal was observed. The second harbor seal was observed on March 
26, 2011, by vessel-based PSO onboard the M/V Dreamcatcher 
approximately 4260 m from the source vessel, which was operating the 10 
in\3\ air gun at the time. The animal was well outside of the 160 dB 
zone (330 m for the 10 in\3\ air gun) and no unusual behaviors were 
observed. The closest haulout site to the action area is located on 
Kalgin Island, which is approximately 22 km away from the McArthur 
River.
    Steller Sea Lion--Two separate stocks of Steller sea lions are 
recognized within U.S. waters: an eastern U.S. stock, which includes 
animals east of Cape Suckling, Alaska; and a western U.S. stock, which 
includes animals west of Cape Suckling (NMFS 2008). Individuals in Cook 
Inlet are considered part of the western U.S. stock, which is listed as 
endangered under the ESA. Steller sea lions primarily occur in lower, 
rather than upper Cook Inlet and are rarely sighted north of Nikiski on 
the Kenai Peninsula. Haul-outs and rookeries are located near Cook 
Inlet at Gore Point, Elizabeth Island, Perl Island, and Chugach Island 
(NMFS 2008). No Steller seal lion haul-outs or rookeries are located in 
the vicinity of the proposed seismic survey. Furthermore, no sightings 
of Steller sea lions were reported by Apache during the 2D test program 
in March 2011. Although Apache has requested takes of Steller sea 
lions, it is unlikely that any Steller sea lions would occur in the 
action are during seismic survey operations.

Potential Number of Takes by Harassment

    This subsection provides estimates of the number of individuals 
potentially exposed to sound levels >=160 dBrms re 1 [mu]Pa 
during seismic survey operations. The estimates were calculated by 
multiplying the expected densities by the anticipated area ensonified 
by levels >=160 dBrms re 1 [mu]Pa by the number of expected 
days that will be subject to seismic survey activities in the action 
area. According to section 2 in Apache's IHA application, a survey crew 
will collect seismic data 10-12 hours per day over approximately 160 
days over the course of 8 to 9 months. Apache assumes that over the 
course of these 160 days, 100 days would be working in the offshore 
region and 60 days would be working in the shallow, intermediate, and 
deep nearshore region. Of those 60 days in the nearshore region, 20 
days would be spent working in each of the three depths. Because 
operations would occur over 12 hours per day, the total number of days 
for each region was divided by two (or half a day) for purposes of 
calculating takes. It is important to note that environmental 
conditions (such as ice, wind, and fog) will play a significant role in 
the actual number of operating days; therefore, these estimates are 
conservative in order to provide a basis for the probability of 
encountering these marine mammal species in the action area.
    The number of estimated takes by Level B harassment was calculated 
using the following assumptions:
     The number of nearshore and shallow water survey days is 
10 (20 days/12 hours) and daily acoustic footprint is 356 km\2\.
     The number of nearshore and intermediate water depth 
survey days is 10 (20 days/12 hours) and daily acoustic footprint is 
468 km\2\.
     The number of nearshore and deep water depth survey days 
is 10 (20 days/12 hours) and daily acoustic footprint is 455 km\2\.
     The number of offshore survey days is 50 (100 days/12 
hours) and daily acoustic footprint is 389 km\2\.
    Table 5 shows the estimated maximum and average takes by species 
for the first year of seismic surveys in Cook Inlet with the methods 
and assumptions outlined above. As noted earlier, the use of the NMML 
aerial survey data has inherent weaknesses that need to be discussed 
further. For example, the estimated number of takes by Level B 
harassment of harbor seals is higher than what is anticipated because 
there are no haul-out sites within the action area. Seals in some 
numbers are expected to be observed in the Susitna River delta, but not 
in the large numbers that are observed in lower Cook Inlet. These 
density estimates are skewed by the numbers observed in large haul outs 
during aerial surveys. Seals in the water usually travel in small 
groups or as single individuals; therefore, although Table 5 indicates 
an average of 102 and maximum of 207 seals exposed to sounds likely to 
result in Level B harassment, it is highly unlikely that those number 
of seals will actually be taken during the proposed seismic survey.
    Similarly, and for many of the same reasons, the number of actual 
takes by

[[Page 58485]]

Level B harassment of Steller sea lions is expected to be much lower 
than the average of four and maximum of 11. During the NMFS aerial 
surveys, no Steller sea lions were observed in upper Cook Inlet. Less 
than five Steller sea lions have been observed by the Port of Anchorage 
monitoring program, and those observed have been juvenile animals 
(likely male). Apache anticipates that there will be less than five 
Steller sea lions in the proposed action area during the one-year 
effective period of the IHA, if issued.
    The average and maximum take estimates for harbor porpoise and 
killer whales shown in Table 5 appear to be reasonable based on the 
NMFS aerial surveys, although the actual number of animals is expected 
to be low.
    The average and maximum estimated number of takes by Level B 
harassment for Cook Inlet beluga whales away from river mouths is two 
and five, respectively. Given that beluga are usually transiting from 
one feeding area to another in lower concentrations, these estimates 
appear to be reasonable in assessing the probability for potentially 
observing beluga whales in the action area. However, it is important to 
note that a combination of visual and acoustic monitoring will be used 
extensively throughout this project, particularly for sighting beluga 
whales approaching the area, so the actual number of takes is expected 
to be lower than these estimates.
    The average and maximum estimated number of takes by Level B 
harassment for Cook Inlet beluga whales near river mouths is 16 and 41 
animals, respectively. The total number of days surveying will actually 
occur near river mouths is much lower than the 160 days used to 
estimate takes in the different water depths; therefore, this take 
estimate is likely to be extremely conservative. As a result, due to 
the actual number of days and hours Apache is likely to be operating 
air guns near river mouths and taking into account the monitoring and 
mitigation measures applicable when operating seismic survey equipment 
near rivers, Apache expects the actual number of takes by Level B 
harassment estimated for Cook Inlet beluga whales to be much lower than 
the numbers provided in Table 5.

                                                     Table 5--Estimated Takes per Species for Year 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Shallow          Mid-depth           Deep            Offshore            Total
                            Species                            -----------------------------------------------------------------------------------------
                                                                  max      avg      max      avg      max      avg      max      avg      max      avg
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga whales--away from river mouths.........................      0.5      0.3      0.7      0.3      0.7      0.3      2.8      1.5      4.7      2.4
Beluga whales--near river mouths..............................      4.5      1.8      5.8      2.3      5.8      2.3     24.8      9.9       41     16.3
Harbor seals..................................................     22.9     11.3     29.5     14.5     29.3     14.4    125.3     61.7      207    101.9
Harbor porpoises..............................................      1.3      0.2      1.7      0.3      1.7      0.3      7.2      1.2     11.9      2.0
Killer whales.................................................      0.4      0.1      0.5      0.1      0.5      0.1      2.2      0.3      3.6      0.5
Steller sea lions.............................................      1.2      0.4      1.6      0.5      1.6      0.5      6.8      2.2     11.3      3.7
--------------------------------------------------------------------------------------------------------------------------------------------------------

Estimated Take Conclusions

    Cetaceans--Effects on cetaceans are generally expected to be 
restricted to avoidance of an area around the seismic survey and short-
term changes in behavior, falling within the MMPA definition of ``Level 
B harassment''.
    Using the 160 dB criterion, the requested take numbers of 
individual cetaceans exposed to sounds [gteqt]160 dBrms re 1 
[mu]Pa represent varying proportions of the populations of each species 
in Cook Inlet (Table 6). For species listed as ``Endangered'' under the 
ESA, the number of takes requested includes 30 Cook Inlet beluga 
whales. This number is approximately 8.5 percent of the population of 
approximately 355 animals (Allen and Angliss 2010). For other cetaceans 
that might occur in the vicinity of the seismic survey in Cook Inlet, 
the requested takes also represent a very small proportion of their 
respective populations. The requested takes of 10 killer whales and 20 
harbor porpoises represent 0.89 percent and 0.06 percent of their 
respective populations in the proposed action area.
    Pinnipeds--Two pinniped species may be encountered in the proposed 
action area, but the harbor seal is likely to be the more abundant 
species in this area. The number of takes requested for individuals 
exposed to sounds at received levels [gteqt]160 dBrms re 1 
[mu]Pa during the proposed seismic survey are as follows: harbor seals 
(50) and Steller sea lions (20). These numbers represent 0.17 percent 
and 0.12 percent of their respective populations in the proposed action 
area.

                                       Table 6--Requested Number of Takes
----------------------------------------------------------------------------------------------------------------
                                                                Number of        Population        Percent of
                          Species                            requested takes      abundance        population
----------------------------------------------------------------------------------------------------------------
Beluga whales.............................................                30               355              8.45
Harbor seals..............................................                50            29,175              0.17
Harbor porpoises..........................................                20            31,406              0.06
Killer whales.............................................                10             1,123              0.89
Steller sea lions.........................................                20            41,197              0.12
----------------------------------------------------------------------------------------------------------------

Negligible Impact and Small Numbers Analysis and Preliminary 
Determination
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``* * * 
an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the takes occur.
    No injuries or mortalities are anticipated to occur as a result of 
Apache's proposed seismic survey in Cook Inlet, and none are proposed 
to be authorized. Additionally, animals in the

[[Page 58486]]

area are not expected to incur hearing impairment (i.e., TTS or PTS) or 
non-auditory physiological effects. Takes will be limited to Level B 
behavioral harassment. Although it is possible that some individuals of 
marine mammals may be exposed to sounds from seismic survey activities 
more than once, the expanse of these multi-exposures are expected to be 
less extensive since both the animals and the survey vessels will be 
moving constantly in and out of the survey areas.
    Odontocete reactions to seismic energy pulses are usually assumed 
to be limited to shorter distances from the airgun(s) than are those of 
mysticetes, probably in part because odontocete low-frequency hearing 
is assumed to be less sensitive than that of mysticetes. However, at 
least when in the Canadian Beaufort Sea in summer, belugas appear to be 
fairly responsive to seismic energy, with few being sighted within 6-12 
mi (10-20 km) of seismic vessels during aerial surveys (Miller et al. 
2005). Belugas will likely occur in small numbers in Cook Inlet during 
the survey period and few will likely be affected by the survey 
activity. In addition, due to the constant moving of the survey vessel, 
the duration of the noise exposure by cetaceans to seismic impulse 
would be brief. For the same reason, it is unlikely that any individual 
animal would be exposed to high received levels multiple times.
    Taking into account the mitigation measures that are planned, 
effects on cetaceans are generally expected to be restricted to 
avoidance of a limited area around the survey operation and short-term 
changes in behavior, falling within the MMPA definition of ``Level B 
harassment''.
    Furthermore, the estimated numbers of animals potentially exposed 
to sound levels sufficient to cause appreciable disturbance are very 
low percentages of the population sizes in Cook Inlet, as described 
above.
    The many reported cases of apparent tolerance by cetaceans of 
seismic exploration, vessel traffic, and some other human activities 
show that co-existence is possible. Mitigation measures such as 
controlled vessel speed, dedicated marine mammal observers, non-
pursuit, and shut downs or power downs when marine mammals are seen 
within defined ranges will further reduce short-term reactions and 
minimize any effects on hearing sensitivity. In all cases, the effects 
are expected to be short-term, with no lasting biological consequence.
    Some individual pinnipeds may be exposed to sound from the proposed 
marine surveys more than once during the time frame of the project. 
However, as discussed previously, due to the constant moving of the 
survey vessel, the probability of an individual pinniped being exposed 
to sound multiple times is much lower than if the source is stationary. 
Therefore, NMFS has preliminarily determined that the exposure of 
pinnipeds to sounds produced by the proposed seismic survey in Cook 
Inlet is not expected to result in more than Level B harassment and is 
anticipated to have no more than a negligible impact on the animals.
    Of the five marine mammal species likely to occur in the proposed 
marine survey area, only Cook Inlet beluga whales and Steller sea lions 
are listed as endangered under the ESA. These species are also 
designated as ``depleted'' under the MMPA. Despite these designations, 
Cook Inlet beluga whales and the western population of Steller sea 
lions have not made significant progress towards recovery. The Cook 
Inlet population of beluga whales has been decreasing at a rate of 1.5 
percent annually for nearly a decade (Allen and Angliss 2010). With 
respect to Steller sea lions, results of aerial surveys conducted in 
2008 (Fritz et al., 2008) confirmed that the recent (2004-2008) overall 
trend in the western population of adult and juvenile Steller sea lions 
in Alaska is stable or possibly in decline; however, there continues to 
be considerable regional variability in recent trends. Pursuant to the 
ESA, critical habitat has been designated for Cook Inlet beluga whales 
and Steller sea lions. The proposed action falls within critical 
habitat designated in Cook Inlet for beluga whales, but is not within 
critical habitat designated for Steller sea lions. None of the other 
species that may occur in the project area are listed as threatened or 
endangered under the ESA or designated as depleted under the MMPA.
    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 rates of recruitment or survival of marine mammals in the 
area. Based on the size of Cook Inlet where feeding by marine mammals 
occurs versus the localized area of the marine survey activities, any 
missed feeding opportunities in the direct project area would be minor 
based on the fact that other feeding areas exist elsewhere.
    The requested takes proposed to be authorized represent 8.5 percent 
of the Cook Inlet beluga whale population of approximately 355 animals 
(Allen and Angliss 2010), 0.89 percent of the combined Alaska resident 
stock and Gulf of Alaska, Aleutian Island and Bering Sea stock of 
killer whales (1,123 residents and 314 transients), and 0.06 percent of 
the Gulf of Alaska stock of approximately 31,046 harbor porpoises. The 
take requests presented for harbor seals represent 0.17 percent of the 
Gulf of Alaska stock of approximately 29,175 animals. Finally, the 
requested takes proposed for Steller sea lions represent 0.12 percent 
of the western stock of approximately 41,197 animals. These estimates 
represent the percentage of each species or stock that could be taken 
by Level B behavioral harassment if each animal is taken only once. In 
addition, the mitigation and monitoring measures (described previously 
in this document) proposed for inclusion in the IHA (if issued) are 
expected to reduce even further any potential disturbance to marine 
mammals.
    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 mitigation and monitoring 
measures, NMFS preliminarily finds that Apache's proposed seismic 
survey in Cook Inlet may result in the incidental take of small numbers 
of marine mammals, by Level B harassment only, and that the total 
taking from the marine surveys will have a negligible impact on the 
affected species or stocks.
Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses
    Section 101(a)(5)(D) also requires NMFS to determine that the 
authorization will not have an unmitigable adverse effect on the 
availability of marine mammal species or stocks for subsistence use. 
NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 as:

    * * * an impact resulting from the specified activity: (1) That 
is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.

    The subsistence harvest of beluga whales transcends the nutritional 
and economic value attributed to the whale and is an integral part of 
the cultural identity of the region's Alaska Native

[[Page 58487]]

communities. Inedible parts of the whale provide Native artisans with 
materials for cultural handicrafts, and the hunting itself perpetuates 
Native traditions by transmitting traditional skills and knowledge to 
younger generations (NOAA 2007). However, due to dramatic declines in 
the Cook Inlet beluga whale population, on May 21, 1999, a temporary 
moratorium on beluga whale harvest was established (Pub. L. 106-31, 
section 3022, 113 Statute (Stat.) 57,100) from 1999 until October 1, 
2000. This moratorium was extended indefinitely on December 21, 2000 
(Pub. L. 106-553, section 1(a)(2), 114 Stat. 2762). NMFS has entered 
into a co-management agreement for beluga whale subsistence harvest. 
Pursuant to that agreement, no hunt has been conducted since 2005 and 
on October 15, 2008, NMFS published a final rule establishing long-term 
limits on the maximum number of Cook Inlet beluga whales that may be 
taken by Alaska Natives for subsistence and handicraft purposes (73 FR 
60976). These rules effectively state that no harvest will be conducted 
until 2012, at which time the possibility of a harvest will be re-
evaluated based on beluga whale population trends.
    With respect to the proposed action, Apache met with the Cook Inlet 
Marine Mammal Council (CIMMC)--a group of Native Alaskans with 
traditional subsistence hunting rights--on March 29, 2011, to discuss 
the proposed activities and discuss any subsistence concerns. In 
addition, Apache met with the Tyonek Native Corporation on November 9, 
2010 and the Salamatof Native Corporation on November 22, 2010. During 
these meetings, no concerns were raised regarding potential conflict 
with subsistence harvest of marine mammals. Apache 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;
     Regional subsistence representatives may support recording 
marine mammal observations along with marine mammal biologists during 
the monitoring programs and will be provided with annual reports; and
     The size of the affected area, mitigation measures, and 
input from the CIMMC should result in the proposed action having no 
effect on the availability of marine mammals for subsistence uses.
    NMFS anticipates that any harassment to marine mammals, including 
Cook Inlet beluga whales, would be short-term, site specific, and 
limited to inconsequential changes in behavior and mild stress 
responses. NMFS does not anticipate that the authorized taking of 
affected species or stocks will result in changes in reproduction, 
survival, or longevity rates, impact population levels, or result in 
changes in distribution. Therefore, NMFS has preliminarily determined 
that the proposed regulations will not have an unmitigable adverse 
impact on the availability of marine mammal stocks for subsistence 
uses.

Endangered Species Act (ESA)

    There are two marine mammal species listed as endangered under the 
ESA with confirmed or possible occurrence in the proposed project area: 
the Cook Inlet beluga whale and Steller sea lion. NMFS' Permits, 
Conservation and Education Division has initiated consultation with 
NMFS' Protected Resources Division under section 7 of the ESA on the 
issuance of an IHA to Apache under section 101(a)(5)(D) of the MMPA for 
this activity. Consultation will be concluded prior to a determination 
on the issuance of an IHA.

National Environmental Policy Act (NEPA)

    NMFS is currently preparing an Environmental Assessment, pursuant 
to NEPA, to determine whether or not this proposed activity may have a 
significant effect on the human environment. This analysis will be 
completed prior to the issuance or denial of the IHA.
Proposed Authorization
    As a result of these preliminary determinations, NMFS proposes to 
authorize the take of marine mammals incidental to Apache's seismic 
survey in Cook Inlet, Alaska, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated.

    Dated: September 15, 2011.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2011-24241 Filed 9-20-11; 8:45 am]
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