Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Marine Seismic Survey in the Beaufort Sea, Alaska, 35851-35874 [2013-14188]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 78, Number 115 (Friday, June 14, 2013)]
[Notices]
[Pages 35851-35874]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-14188]



[[Page 35851]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC564


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Marine Seismic Survey in the 
Beaufort Sea, 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 SAExploration, Inc. (SAE) 
for an Incidental Harassment Authorization (IHA) to take marine 
mammals, by harassment only, incidental to a marine 3-dimensional (3D) 
ocean bottom cable (OBC) seismic surveys program in the state and 
federal waters of the Beaufort Sea, Alaska, during the open water 
season of 2013. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an IHA to SAE to 
take, by Level B harassment, nine species of marine mammals during the 
specified activity.

DATES: Comments and information must be received no later than July 15, 
2013.

ADDRESSES: Comments on the application should be addressed to P. 
Michael Payne, Chief, Permits and Conservation Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910. The mailbox address for providing 
email comments is ITP.guan@noaa.gov. NMFS is not responsible for email 
comments sent to addresses other than the one provided here. Comments 
sent via email, 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 https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications 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.
    The application used in this document may be obtained by visiting 
the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Documents cited in this notice may also be 
viewed, by appointment, during regular business hours, at the 
aforementioned address.

FOR FURTHER INFORMATION CONTACT: Shane Guan, 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

    On December 12, 2012, NMFS received an application from SAE 
requesting an authorization for the harassment of small numbers of 
marine mammals incidental to conducting an open water 3D OBC seismic 
survey in the Beaufort Sea off Alaska. After addressing comments from 
NMFS, SAE modified its application and submitted a revised application 
on April 14, 2013. SAE's proposed activities discussed here are based 
on its April 14, 2013, IHA application.

Description of the Specified Activity

    The planned 3D seismic survey would occur in the nearshore waters 
of the Colville River Delta in the Alaskan Beaufort Sea (Figure 1-1 of 
SAE's IHA application). The components of the project include laying 
nodal recording sensors (nodes) on the ocean floor, operating seismic 
source vessels towing active airgun arrays, and retrieval of nodes. 
There will also be additional boat activity associated with crew 
transfer, recording support, and additional monitoring for marine 
mammals.
    A total of 210 nodal (receiver) lines will be laid perpendicular 
from the shoreline spaced 200 to 268 m (660 to 880 ft) apart. Receiver 
line lengths range between 20 and 32 km (13 and 20 mi) long. The total 
receiver area is 1,225 km\2\ (473 mi\2\). Sixty-five source (shot) 
transect lines will run perpendicular to the receiver nodal lines, each 
spaced 300 to 335 m (990 to 1,100 ft) apart. These lines will be 
approximately 51 km (32 mi) long. The total source survey area is 995 
km\2\ (384 mi\2\).
    The receiver layout and seismic survey data will be acquired using 
the stroke technique--multiple strokes with 6 receiver lines per 
stroke. Source lines will be acquired perpendicular to the receiver 
lines for each stroke, only 6 receiver lines will be laid at a time, 
with enough associated source survey to fully acquisition data for that 
stroke. Once data is acquired for a given stroke, the nodal lines 
(strings of individual nodes tethered together by rope) will be 
retrieved and repositioned into a second 6 line stroke, and the seismic 
survey operations begin anew. This will allow the most rapid 
acquisition of data using the minimum number of active nodes.

Acoustical Sources

    The acoustic sources of primary concern are the airguns that will 
be deployed from the seismic source

[[Page 35852]]

vessels. However, there are other noise sources to be addressed 
including the pingers and transponders associated with locating 
receiver nodes, as well as propeller noise from the vessel fleet.
    The seismic sources to be used will include using 880 and 1,760 
cubic inch (in\3\) sleeve airgun arrays for use in the deeper waters, 
and a 440 in\3\ array in the very shallow (<1.5 m) water locations. The 
arrays will be towed approximately 15 to 22 m (50 to 75 ft) behind the 
source vessel stern, at a depth of 4 m (12 ft), and towed along 
predetermined source lines at speeds between 4 and 5 knots. Two vessels 
with full arrays will be operating simultaneously in an alternating 
shot mode; one vessel shooting while the other is recharging. Shot 
intervals are expected to be about 8 to 10 seconds for each array 
resulting in an overall shot interval of 4 to 5 seconds considering the 
two arrays. Operations are expected to occur 24 hours a day.
    Based on the manufacturer's specifications, the 440 in\3\ array has 
a peak-peak estimated 1-meter sound source of 239.1 dB re 1 [mu]Pa, and 
root mean square (rms) at 221.1 dB re 1 [mu]Pa. The 880 in\3\ array 
produces sound levels at source estimated at peak-peak 244.86 dB re 1 
[mu]Pa @ 1 m, and rms at 226.86 dB re 1 [mu]Pa. The 1,760 in\3\ array 
has a peak-peak estimated sound source of 254.55 dB re 1 [mu]Pa @ 1 m, 
with an rms sound source of 236.55 dB re 1 [mu]Pa. The 1,760 in\3\ 
array has a sound source level approximately 10 dB higher than the 880 
in\3\ array.

Pingers and Transponders

    An acoustical pinger system will be used to position and 
interpolate the location of the nodes. Pingers will be positioned at 
predetermined intervals throughout the shoot patch and signals 
transmitted by the pingers will be received by a transponder mounted on 
a recording and retrieving vessel. The pingers and transponder 
communicate via sonar and, therefore, each generates underwater sounds 
potentially disturbing to marine mammals. The exact model of pinger 
system to be used is yet to be determined, but available pingers 
transmit short pulses at between 19 to 55 kHz and have published source 
levels between 185 and 193 dB (rms) re 1 [mu]Pa @ 1 m. Available 
transponders generally transmit at between 7 and 50 kHz, with similar 
source levels also between 185 and 193 dB re 1 [mu]Pa @ 1 m. Aerts et 
al. (2008) measured the sound source signature of the same pingers and 
transponders to be used in this survey and found the pinger to have a 
source level of 185 dB re 1 [mu]Pa and the transponder at 193 dB re 1 
[mu]Pa.
    Both the pingers and the transponders produce noise levels within 
the most sensitive hearing range of seals (10 to 30 kHz; Schusterman 
1981) and beluga whales (12 to ~100 kHz; Wartzok and Ketten 1999), and 
the functional hearing range of baleen whales (20 Hz to 30 kHz; NRC 
2003), although baleen whale hearing is probably most sensitive nearer 
1 kHz (Richardson et al. 1995). However, given the low acoustical 
output, the range of acoustical harassment to marine mammals is between 
about 24 to 61 m (80 and 200 ft), or significantly less than the output 
from the airgun arrays (see below).

Vessels

    Several offshore vessels will be required to support recording, 
shooting, and housing in the marine and transition zone environments. 
The exact vessels that will be used have not yet been determined. 
However, the types of vessels that will be used to fulfill these roles 
are listed in Table 1.
    Source Vessels--Source vessels will have the ability to deploy two 
arrays off the stern using large A-frames and winches and have a draft 
shallow enough to operate in waters less than 1.5 m (5 ft) deep. On the 
source vessels the airgun arrays are typically mounted on the stern 
deck with an umbilical that allow the arrays to be deployed and towed 
from the stern without having to re-rig or move arrays. A large bow 
deck will allow for sufficient space for source compressors and 
additional airgun equipment to be stored. The two marine vessels likely 
to be used are the Peregrine and Miss Diane. Both were acoustically 
measured by Aerts et al. (2008). The Peregrine was found to have a 
source level of 179.0 dB re 1 [mu]Pa, while the smaller Miss Diane has 
a source level of 165.7 dB re 1 [mu]Pa.

                         Table 1--Vessels To Be Used During SAE's 3D OBC Seismic Surveys
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                                                                                                   Source level
                   Vessel                       Size (ft)           Activity and frequency             (dB)
----------------------------------------------------------------------------------------------------------------
Source vessel 1............................        120 x 25  Seismic data acquisition; 24 hr                 179
                                                              operation.
Source vessel 2............................         80 x 25  Seismic data acquisition; 24 hr                 166
                                                              operation.
Node equipment vessel 1....................         80 x 20  Deploying and retrieving nodes; 24              165
                                                              hr operation.
Node equipment vessel 2....................         80 x 20  Deploying and retrieving nodes; 24              165
                                                              hr operation.
Mitigation/housing vessel..................         90 x 20  House crew; 24 hr operation........             200
Crew transport vessel......................         30 x 20  Transport crew; intermittent 8 hrs.             192
Bow picker 1...............................         30 x 20  Deploying & retrieving nodes;                   172
                                                              intermittent operation.
Bow picker 2...............................         30 x 20  Deploying & retrieving nodes;                   172
                                                              intermittent operation.
----------------------------------------------------------------------------------------------------------------

    Recording Deployment and Retrieval--Jet driven shallow draft 
vessels and bow pickers will be used for the deployment and retrieval 
of the offshore recording equipment. These vessels will be rigged with 
hydraulically driven deployment and retrieval squirters allowing for 
automated deployment and retrieval from the bow or stern of the vessel. 
These vessels will also carry the recording equipment on the deck in 
fish totes. Aerts et al. (2008) found the recording and deployment 
vessels to have a source level of approximately 165.3 dB re 1 [mu]Pa, 
while the smaller bow pickers produce more cavitation resulting in 
source levels of 171.8 dB re 1 [mu]Pa.
    Housing and Transfer Vessels--Housing vessel(s) will be larger with 
sufficient berthing to house crews and management. The housing vessel 
will have ample office and bridge space to facilitate the role as the 
mother ship and central operations. Crew transfer vessels will be 
sufficiently large to safely transfer crew between vessels as needed. 
Aerts et al. (2008) found the housing vessel to produce the loudest 
propeller noise of all the vessels in the fleet (200.1 dB re 1 [mu]Pa), 
but this vessel is mostly anchored up once it gets on site. The crew 
transfer vessel also travels only infrequently relative to other 
vessels, and is usually operated at different speeds. During higher 
speed runs the vessel produces source noise levels of about 191.8 dB re 
1 [mu]Pa, while during slower on-site movements the vessel source 
levels are only 166.4 dB re 1 [mu]Pa (Aerts et al. 2008).

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    Mitigation Vessel--To facilitate marine mammal monitoring of the 
Level B harassment zone, one dedicated vessel will be deployed a few 
kilometers northeast of the active seismic source vessels to provide a 
survey platform for 2 or 3 Protected Species Observers (PSOs). These 
PSOs will work in concert with PSOs stationed aboard the source 
vessels, and will provide an early warning of the approach of any 
bowhead whale, beluga, or other marine mammal. It is assumed that the 
vessel will be of similar size and acoustical signature as a bowpicker.

Acoustic Footprint

    SAE used the JASCO model provided in Aerts et al. (2008) to predict 
its source levels for the 880 and 1,760 in\3\ airgun array, corrected 
with the measured or manufacture's source levels. For the 440-in\3\ and 
880-in\3\ arrays, the choices were to either use the radii values 
already determined by Aerts et al. (2008), further choosing between the 
50th or 100th percentile values, or applying factory-measured sound 
source levels to the model. Aerts et al. (2008) did not measure the 
1,760-in\3\ array, so the former choice is not available for this 
array.
    While NMFS and SAE considered using the 100th percentile values 
generated by Aerts et al. (2008) to estimate the airgun array source 
would have the benefit of being the most protective approach, it was 
not used because the estimated value from this model is very unlikely 
to represent the actual source level as the model is based on far-field 
measurements. In addition, a close examination of the endfire 
measurements in Figure 3.4 provided by Aerts et al. (2008) show that 
the measured values within 600 m of the source nearly all fall along or 
below the 50th percentile line, while the 100th percentile is 
influenced by values between 600 and 1,000 m. Therefore, NMFS believes 
that the 50th percentile or 230.9 dB is closer to the actual source 
level of the 880-in\3\ airgun array, which was also supported by the 
550 m of measurements (between 50 and 600 m) during the BP's sound 
source verification (SSV) measurements reported by Aerts et al. (2008). 
The modeled source levels of 230.9 dB for the 880-in\3\ array is still 
higher than the manufacture source value for the SeaScan 880-in\3\ 
array (peak to peak 17.5 bar-m, which is roughly equivalent to 226.86 
dB rms).
    Applying the 230.9 dB modeled source level for the 880 in\3\ array 
to JASCO's modeled propagation equation for the same volume of airgun 
array,

18 Log(R)-0.0047(R)

(where R is the range in meter from the source), which was based on 
BP's SSV measurements (Aerts et al. 2008), results in exclusion zone 
radii of 167 m (190 dB) and 494 m (180 dB).
    Similar modeling effects were done on the 440-in\3\ array, which 
results inexclusion zone radii of 126 m (190 dB) and 325 m (180 dB).
    However, this approach does not work for establishing safety radii 
for the 1,760-in\3\ array as Aerts et al. (2008) did not measure such 
an array. Using the manufacturer source value of 236.6 dB rms and the 
JASCO model, 18 Log(R)-0.0047(R), yields safety radii of 321 m (190 dB) 
and 846 m (180 dB).
    A similar method was used to calculate the estimated 160 dB radii 
for the three different volumes of airgun arrays. A summary of airgun 
array modeled source levels and their respective exclusion zones are 
listed in Table 2.

           Table 2--Modeled Airgun Array Source Levels and Exclusion Zone and Zones of Influence Radii
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                                                   Source level    190 dB radius   180 dB radius   160 dB radius
               Array size  (in\3\)                     (dB)             (m)             (m)             (m)
----------------------------------------------------------------------------------------------------------------
440.............................................          221.10             126             325           1,330
880.............................................          226.86             167             494           1,500
1,760...........................................          236.55             321             842           2,990
----------------------------------------------------------------------------------------------------------------

    While the pingers and transponders that will be used to relocate 
nodes generate sound source levels at approximately 185 to 193 dB re 1 
[micro]Pa, the associated exclusion zones are estimated at about 0 to 6 
m from the source.

Dates and Duration of the Proposed Seismic Survey

    SAE's proposed 3D OBC seismic survey is for the 2013 open water 
season between July 1 and October 15. All associated activities, 
including mobilization, survey activities, and demobilization of survey 
and support crews, would occur inclusive of the above dates. The actual 
data acquisition is expected to take approximately 70 days (July 25 to 
September 30), dependent of weather. Based on past similar seismic 
shoots in the Beaufort Sea, it is expected that effective shooting 
would occur over about 70 percent of the 70 days (or about 1,176 
hours). If required in the Conflict Avoidance Agreement (CAA), surveys 
will temporarily cease during the fall bowhead whale hunt to avoid 
acoustical interference with the Cross Island, Kaktovik, or Barrow 
based hunts. Still, seismic surveys will begin in the more offshore 
areas first with the intention of completing survey of the bowhead 
whale migration corridor (waters >15 meters deep) region prior to the 
arrival of the fall migration. It is expected that by September 1, the 
northernmost 8 to 10 kilometers of the survey box will have been shot, 
with the remaining area to be surveyed found 5 to 8 kilometers south of 
the southern edge of the bowhead migration corridor (the 15-meter 
isobath).

Description of Marine Mammals in the Area of the Specified Activity

    The marine mammal species under NMFS jurisdiction most likely to 
occur in the seismic survey area include five cetacean species, beluga 
whale (Delphinapterus leucas), narwhal (Monodon monoceros), bowhead 
whale (Balaena mysticetus), gray whale (Eschrichtius robustus), and 
humpback whale (Megaptera novaeangliae), and four pinniped species, 
ringed (Phoca hispida), spotted (P. largha), bearded (Erignathus 
barbatus), and ribbon seals (Histriophoca fasciata).
    The bowhead and humpback whales are listed as ``endangered'', and 
the ringed and bearded seals are listed as ``threatened'' under the 
Endangered Species Act (ESA) and as depleted under the MMPA. Certain 
stocks or populations of gray and beluga whales and spotted seals are 
also listed under the ESA, however, none of those stocks or populations 
occur in the proposed activity area.
    SAE'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

[[Page 35854]]

ADDRESSES). Additional information can also be found in the NMFS Stock 
Assessment Reports (SAR). The Alaska 2012 SAR is available at: https://www.nmfs.noaa.gov/pr/sars/pdf/ak2012.pdf.

Potential Effects of the Specified Activity on Marine Mammals

    Operating active acoustic sources such as airgun arrays, 
navigational sonars, and vessel activities have the potential for 
adverse effects on marine mammals.

Potential Effects of Airgun Sounds on Marine Mammals

    The effects of sounds from airgun pulses might include one or more 
of the following: tolerance, masking of natural sounds, behavioral 
disturbance, and temporary or permanent hearing impairment or non-
auditory effects (Richardson et al. 1995). As outlined in previous NMFS 
documents, the effects of noise on marine mammals are highly variable, 
and can be categorized as follows (based on Richardson et al. 1995):
(1) 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 could be expected to be biologically significant if the 
change affects growth, survival, and reproduction. Some of these 
potential 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 160 dB re 1 [mu]Pa (rms) at received level for 
impulse noises (such as airgun pulses) as the threshold for the onset 
of marine mammal behavioral harassment.
    In addition, behavioral disturbance is also expressed as the change 
in vocal activities of animals. For example, there is one recent 
summary report indicating that calling fin whales distributed in one 
part of the North Atlantic went silent for an extended period starting 
soon after the onset of a seismic survey in the area (Clark and Gagnon 
2006). It is not clear from that preliminary paper whether the whales 
ceased calling because of masking, or whether this was a behavioral 
response not directly involving masking (i.e., important biological 
signals for marine mammals being ``masked'' by anthropogenic noise; see 
below). Also, bowhead whales in the Beaufort Sea may decrease their 
call rates in response to seismic operations, although movement out of 
the area might also have contributed to the lower call detection rate 
(Blackwell et al. 2009a; 2009b). Some of the changes in marine mammal 
vocal communication are thought to be used to compensate for acoustic 
masking resulting from increased anthropogenic noise (see below). 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 
2009). The North Atlantic right whales (Eubalaena glacialis) exposed to 
high shipping noise increase call frequency (Parks et al. 2007) and 
intensity (Parks et al. 2010), while some humpback whales respond to 
low-frequency active sonar playbacks by increasing song length (Miller 
el al. 2000). These behavioral responses could also have adverse 
effects on marine mammals.
    Mysticetes: Baleen whales generally tend to avoid operating 
airguns, but avoidance radii are quite variable. Whales are often 
reported to show no overt reactions to airgun pulses at distances 
beyond a few kilometers, even though the airgun pulses remain well 
above ambient noise levels out to much longer distances (reviewed in 
Richardson et al. 1995; Gordon et al. 2004). However, studies done 
since the late 1990s of migrating humpback and migrating bowhead whales 
show reactions, including avoidance, that sometimes extend to greater 
distances than documented earlier. Therefore, it appears that 
behavioral disturbance can vary greatly depending on context, and not 
just received levels alone. Avoidance distances often exceed the 
distances at which boat-based observers can see whales, so observations 
from the source vessel can be biased. Observations over broader areas 
may be needed to determine the range of potential effects of some 
large-source seismic surveys where effects on cetaceans may extend to 
considerable distances (Richardson et al. 1999; Moore and Angliss 
2006). Longer-range observations, when required, can sometimes be 
obtained via systematic aerial surveys or aircraft-based observations 
of behavior (e.g., Richardson et al. 1986, 1999; Miller et al. 1999, 
2005; Yazvenko et al. 2007a, 2007b) or by use of observers on one or 
more support vessels operating in coordination with the seismic vessel 
(e.g., Smultea et al. 2004; Johnson et al. 2007). However, the presence 
of other vessels near the source vessel can, at least at times, reduce 
sightability of cetaceans from the source vessel (Beland et al. 2009), 
thus complicating interpretation of sighting data.
    Some baleen whales show considerable tolerance of seismic pulses. 
However, when the pulses are strong enough, avoidance or other 
behavioral changes become evident. Because the responses become less 
obvious with diminishing received sound level, it has been difficult to 
determine the maximum distance (or minimum received sound level) at 
which reactions to seismic activity become evident and, hence, how many 
whales are affected.
    Studies of gray, bowhead, and humpback whales have determined that 
received levels of pulses in the 160-170 dB re 1 [mu]Pa (rms) range 
seem to cause obvious avoidance behavior in a substantial fraction of 
the animals exposed (McCauley et al. 1998, 1999, 2000). In many areas, 
seismic pulses diminish to these levels at distances ranging from 4-15 
km from the source. A substantial proportion of the baleen whales 
within such distances may show avoidance or other strong disturbance 
reactions to the operating airgun array. Some extreme examples 
including migrating bowhead whales avoiding considerably larger 
distances (20-30 km) and lower received sound levels

[[Page 35855]]

(120-130 dB re 1 [mu]Pa (rms)) when exposed to airguns from seismic 
surveys. Also, even in cases where there is no conspicuous avoidance or 
change in activity upon exposure to sound pulses from distant seismic 
operations, there are sometimes subtle changes in behavior (e.g., 
surfacing-respiration-dive cycles) that are only evident through 
detailed statistical analysis (e.g., Richardson et al. 1986; Gailey et 
al. 2007).
    Data on short-term reactions by cetaceans to impulsive noises are 
not necessarily indicative of long-term or biologically significant 
effects. It is not known whether impulsive sounds affect reproductive 
rate or distribution and habitat use in subsequent days or years. 
However, gray whales have continued to migrate annually along the west 
coast of North America despite intermittent seismic exploration (and 
much ship traffic) in that area for decades (Appendix A in Malme et al. 
1984; Richardson et al. 1995), and there has been a substantial 
increase in the population over recent decades (Allen and Angliss 
2010). The western Pacific gray whale population did not seem affected 
by a seismic survey in its feeding ground during a prior year (Johnson 
et al. 2007). Similarly, bowhead whales have continued to travel to the 
eastern Beaufort Sea each summer despite seismic exploration in their 
summer and autumn range for many years (Richardson et al. 1987), and 
their numbers have increased notably (Allen and Angliss 2010). Bowheads 
also have been observed over periods of days or weeks in areas 
ensonified repeatedly by seismic pulses (Richardson et al. 1987; Harris 
et al. 2007). However, it is generally not known whether the same 
individual bowheads were involved in these repeated observations 
(within and between years) in strongly ensonified areas.
    Odontocete: Relatively little systematic information is available 
about reactions of toothed whales to airgun pulses. A few studies 
similar to the more extensive baleen whale/seismic pulse work 
summarized above have been reported for toothed whales. However, there 
are recent systematic data on sperm whales (e.g., Gordon et al. 2006; 
Madsen et al. 2006; Winsor and Mate 2006; Jochens et al. 2008; Miller 
et al. 2009) and beluga whales (e.g., Miller et al. 2005). There is 
also an increasing amount of information about responses of various 
odontocetes to seismic surveys based on monitoring studies (e.g., Stone 
2003; Smultea et al. 2004; Moulton and Miller 2005; Holst et al. 2006; 
Stone and Tasker 2006; Potter et al. 2007; Hauser et al. 2008; Holst 
and Smultea 2008; Weir 2008; Barkaszi et al. 2009; Richardson et al. 
2009).
    Dolphins and porpoises are often seen by observers on active 
seismic vessels, occasionally at close distances (e.g., bow riding). 
Marine mammal monitoring data during seismic surveys often show that 
animal detection rates drop during the firing of seismic airguns, 
indicating that animals may be avoiding the vicinity of the seismic 
area (Smultea et al. 2004; Holst et al. 2006; Hauser et al. 2008; Holst 
and Smultea 2008; Richardson et al. 2009). Also, belugas summering in 
the Canadian Beaufort Sea showed larger-scale avoidance, tending to 
avoid waters out to 10-20 km from operating seismic vessels (Miller et 
al. 2005). In contrast, recent studies show little evidence of 
conspicuous reactions by sperm whales to airgun pulses, contrary to 
earlier indications (e.g., Gordon et al. 2006; Stone and Tasker 2006; 
Winsor and Mate 2006; Jochens et al. 2008), except the lower buzz 
(echolocation signals) rates that were detected during exposure of 
airgun pulses (Miller et al. 2009).
    There are almost no specific data on responses of beaked whales to 
seismic surveys, but it is likely that most if not all species show 
strong avoidance. There is increasing evidence that some beaked whales 
may strand after exposure to strong noise from tactical military mid-
frequency sonars. Whether they ever do so in response to seismic survey 
noise is unknown. Northern bottlenose whales seem to continue to call 
when exposed to pulses from distant seismic vessels.
    For delphinids, and possibly the Dall's porpoise, the available 
data suggest that a >=170 dB re 1 [mu]Pa (rms) disturbance criterion 
(rather than >=160 dB) would be appropriate. With a medium-to-large 
airgun array, received levels typically diminish to 170 dB within 1-4 
km, whereas levels typically remain above 160 dB out to 4-15 km (e.g., 
Tolstoy et al. 2009). Reaction distances for delphinids are more 
consistent with the typical 170 dB re 1 [mu]Pa (rms) distances. Stone 
(2003) and Stone and Tasker (2006) reported that all small odontocetes 
(including killer whales) observed during seismic surveys in UK waters 
remained significantly further from the source during periods of 
shooting on surveys with large volume airgun arrays than during periods 
without airgun shooting.
    Due to their relatively higher frequency hearing ranges when 
compared to mysticetes, odontocetes may have stronger responses to mid- 
and high-frequency sources such as sub-bottom profilers, side scan 
sonar, and echo sounders than mysticetes (Richardson et al. 1995; 
Southall et al. 2007).
    Pinnipeds: Few studies of the reactions of pinnipeds to noise from 
open-water seismic exploration have been published (for review of the 
early literature, see Richardson et al. 1995). However, pinnipeds have 
been observed during a number of seismic monitoring studies. Monitoring 
in the Beaufort Sea during 1996-2002 provided a substantial amount of 
information on avoidance responses (or lack thereof) and associated 
behavior. Additional monitoring of that type has been done in the 
Beaufort and Chukchi Seas in 2006-2009. Pinnipeds exposed to seismic 
surveys have also been observed during seismic surveys along the U.S. 
west coast. Also, there are data on the reactions of pinnipeds to 
various other related types of impulsive sounds.
    Early observations provided considerable evidence that pinnipeds 
are often quite tolerant of strong pulsed sounds. During seismic 
exploration off Nova Scotia, gray seals exposed to noise from airguns 
and linear explosive charges reportedly did not react strongly (J. 
Parsons in Greene et al. 1985). An airgun caused an initial startle 
reaction among South African fur seals but was ineffective in scaring 
them away from fishing gear. Pinnipeds in both water and air sometimes 
tolerate strong noise pulses from non-explosive and explosive scaring 
devices, especially if attracted to the area for feeding or 
reproduction (Mate and Harvey 1987; Reeves et al. 1996). Thus, 
pinnipeds are expected to be rather tolerant of, or to habituate to, 
repeated underwater sounds from distant seismic sources, at least when 
the animals are strongly attracted to the area.
    In summary, visual monitoring from seismic vessels has shown only 
slight (if any) avoidance of airguns by pinnipeds, and only slight (if 
any) changes in behavior. These studies show that many pinnipeds do not 
avoid the area within a few hundred meters of an operating airgun 
array. However, based on the studies with large sample size, or 
observations from a separate monitoring vessel, or radio telemetry, it 
is apparent that some phocid seals do show localized avoidance of 
operating airguns. The limited nature of this tendency for avoidance is 
a concern. It suggests that one cannot rely on pinnipeds to move away, 
or to move very far away, before received levels of sound from an 
approaching seismic survey vessel approach those that may cause hearing 
impairment.

[[Page 35856]]

(2) Masking
    Masking occurs when noise and signals (that animal utilizes) 
overlap at both spectral and temporal scales. Chronic exposure to 
elevated sound levels could cause masking at particular frequencies for 
marine mammals, which utilize sound for important biological functions. 
Masking can interfere with detection of acoustic signals used for 
orientation, communication, finding prey, and avoiding predators. 
Marine mammals that experience severe (high intensity and extended 
duration) acoustic masking could potentially suffer reduced fitness, 
which could lead to adverse effects on survival and reproduction.
    For the airgun noise generated from the proposed marine seismic 
survey, these are low frequency (under 1 kHz) pulses with extremely 
short durations (in the scale of milliseconds). 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 due to the brief 
duration of these pulses and relatively longer silence between airgun 
shots (9-12 seconds) near the noise source, however, at long distances 
(over tens of kilometers away) in deep water, due to multipath 
propagation and reverberation, the durations of airgun pulses can be 
``stretched'' to seconds with long decays (Madsen et al. 2006; Clark 
and Gagnon 2006). Therefore it 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. 
2009a, 2009b) and affect their vocal behavior (e.g., Foote et al. 2004; 
Holt et al. 2009). Further, in areas of shallow water, multipath 
propagation of airgun pulses could be more profound, thus affecting 
communication signals from marine mammals even at close distances. 
Average ambient noise in areas where received seismic noises are heard 
can be elevated. At long distances, however, the intensity of the noise 
is greatly reduced. Nevertheless, partial informational and energetic 
masking of different degrees could affect signal receiving in some 
marine mammals within the ensonified areas. Additional research is 
needed to further address these effects.
    Although masking effects of pulsed sounds on marine mammal calls 
and other natural sounds are expected to be limited, there are few 
specific studies on this. Some whales continue calling in the presence 
of seismic pulses and whale calls often can be heard between the 
seismic pulses (e.g., Richardson et al. 1986; McDonald et al. 1995; 
Greene et al. 1999a, 1999b; Nieukirk et al. 2004; Smultea et al. 2004; 
Holst et al. 2005a, 2005b, 2006; Dunn and Hernandez 2009).
    Among the odontocetes, there has been one report that sperm whales 
ceased calling when exposed to pulses from a very distant seismic ship 
(Bowles et al. 1994). However, more recent studies of sperm whales 
found that they continued calling in the presence of seismic pulses 
(Madsen et al. 2002; Tyack et al. 2003; Smultea et al. 2004; Holst et 
al. 2006; Jochens et al. 2008). Madsen et al. (2006) noted that airgun 
sounds would not be expected to mask sperm whale calls given the 
intermittent nature of airgun pulses. Dolphins and porpoises are also 
commonly heard calling while airguns are operating (Gordon et al. 2004; 
Smultea et al. 2004; Holst et al. 2005a, 2005b; Potter et al. 2007). 
Masking effects of seismic pulses are expected to be negligible in the 
case of the smaller odontocetes, given the intermittent nature of 
seismic pulses plus the fact that sounds important to them are 
predominantly at much higher frequencies than are the dominant 
components of airgun sounds.
    Pinnipeds have best hearing sensitivity and/or produce most of 
their sounds at frequencies higher than the dominant components of 
airgun sound, but there is some overlap in the frequencies of the 
airgun pulses and the calls. However, the intermittent nature of airgun 
pulses presumably reduces the potential for masking.
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior such as shifting call frequencies, 
and increasing call volume and vocalization rates, as discussed earlier 
(e.g., Miller et al. 2000; Parks et al. 2007; Di Iorio and Clark 2009; 
Parks et al. 2010); the biological significance of these modifications 
is still unknown.
(3) 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). Marine mammals 
that experience TTS or PTS will have reduced sensitivity at the 
frequency band of the TS, which may affect their capability of 
communication, orientation, or prey detection. The degree of TS depends 
on the intensity of the received levels the animal is exposed to, and 
the frequency at which TS occurs depends on the frequency of the 
received noise. It has been shown that in most cases, TS occurs at the 
frequencies approximately one-octave above that of the received noise. 
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.
    TTS:
    TTS is the mildest form of hearing impairment that can occur during 
exposure to a strong sound (Kryter 1985). While experiencing TTS, the 
hearing threshold rises and a sound must be stronger in order to be 
heard. It is a temporary phenomenon, and (especially when mild) is not 
considered to represent physical damage or ``injury'' (Southall et al. 
2007). Rather, the onset of TTS is an indicator that, if the animal is 
exposed to higher levels of that sound, physical damage is ultimately a 
possibility.
    The magnitude of TTS depends on the level and duration of noise 
exposure, and to some degree on frequency, among other considerations 
(Kryter 1985; Richardson et al. 1995; Southall et al. 2007). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
recovers rapidly after exposure to the noise ends. In terrestrial 
mammals, TTS can last from minutes or hours to (in cases of strong TTS) 
days. Only a few data have been obtained on sound levels and durations 
necessary to elicit mild TTS in marine mammals (none in mysticetes), 
and none of the published data concern TTS elicited by exposure to 
multiple pulses of sound during operational seismic surveys (Southall 
et al. 2007).
    For toothed whales, experiments on a bottlenose dolphin (Tursiops 
truncates) and beluga whale showed that exposure to a single watergun 
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.
    Finneran et al. (2005) further examined the effects of tone 
duration on TTS in bottlenose dolphins. Bottlenose dolphins were 
exposed to 3 kHz tones (non-impulsive) for periods of 1, 2, 4 or

[[Page 35857]]

8 seconds (s), with hearing tested at 4.5 kHz. For 1-s exposures, TTS 
occurred with SELs of 197 dB, and for exposures >1 s, SEL >195 dB 
resulted in TTS (SEL is equivalent to energy flux, in dB re 1 
[mu]Pa\2\-s). At an SEL of 195 dB, the mean TTS (4 min after exposure) 
was 2.8 dB. Finneran et al. (2005) suggested that an SEL of 195 dB is 
the likely threshold for the onset of TTS in dolphins and belugas 
exposed to tones of durations 1-8 s (i.e., TTS onset occurs at a near-
constant SEL, independent of exposure duration). That implies that, at 
least for non-impulsive tones, a doubling of exposure time results in a 
3 dB lower TTS threshold.
    However, the assumption that, in marine mammals, the occurrence and 
magnitude of TTS is a function of cumulative acoustic energy (SEL) is 
probably an oversimplification. Kastak et al. (2005) reported 
preliminary evidence from pinnipeds that, for prolonged non-impulse 
noise, higher SELs were required to elicit a given TTS if exposure 
duration was short than if it was longer, i.e., the results were not 
fully consistent with an equal-energy model to predict TTS onset. 
Mooney et al. (2009a) showed this in a bottlenose dolphin exposed to 
octave-band non-impulse noise ranging from 4 to 8 kHz at SPLs of 130 to 
178 dB re 1 [mu]Pa for periods of 1.88 to 30 minutes (min). Higher SELs 
were required to induce a given TTS if exposure duration was short than 
if it was longer. Exposure of the aforementioned bottlenose dolphin to 
a sequence of brief sonar signals showed that, with those brief (but 
non-impulse) sounds, the received energy (SEL) necessary to elicit TTS 
was higher than was the case with exposure to the more prolonged 
octave-band noise (Mooney et al. 2009b). Those authors concluded that, 
when using (non-impulse) acoustic signals of duration ~0.5 s, SEL must 
be at least 210-214 dB re 1 [mu]Pa\2\-s to induce TTS in the bottlenose 
dolphin. The most recent studies conducted by Finneran et al. also 
support the notion that exposure duration has a more significant 
influence compared to SPL as the duration increases, and that TTS 
growth data are better represented as functions of SPL and duration 
rather than SEL alone (Finneran et al. 2010a, 2010b). In addition, 
Finneran et al. (2010b) conclude that when animals are exposed to 
intermittent noises, there is recovery of hearing during the quiet 
intervals between exposures through the accumulation of TTS across 
multiple exposures. Such findings suggest that when exposed to multiple 
seismic pulses, partial hearing recovery also occurs during the seismic 
pulse intervals.
    For baleen whales, there are no data, direct or indirect, on levels 
or properties of sound that are required to induce TTS. The frequencies 
to which baleen whales are most sensitive are lower than those to which 
odontocetes are most sensitive, and natural ambient noise levels at 
those low frequencies tend to be higher (Urick 1983). As a result, 
auditory thresholds of baleen whales within their frequency band of 
best hearing are believed to be higher (less sensitive) than are those 
of odontocetes at their best frequencies (Clark and Ellison 2004). From 
this, it is suspected that received levels causing TTS onset may also 
be higher in baleen whales. However, no cases of TTS are expected given 
the small size of the airguns proposed to be used and the strong 
likelihood that baleen whales (especially migrating bowheads) would 
avoid the approaching airguns (or vessel) before being exposed to 
levels high enough for there to be any possibility of TTS.
    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). 
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).
    Most cetaceans show some degree of avoidance of seismic vessels 
operating an airgun array (see above). It is unlikely that these 
cetaceans would be exposed to airgun pulses at a sufficiently high 
level for a sufficiently long period to cause more than mild TTS, given 
the relative movement of the vessel and the marine mammal. TTS would be 
more likely in any odontocetes that bow- or wake-ride or otherwise 
linger near the airguns. However, while bow- or wake-riding, 
odontocetes would be at the surface and thus not exposed to strong 
sound pulses given the pressure release and Lloyd Mirror effects at the 
surface. But if bow- or wake-riding animals were to dive intermittently 
near airguns, they would be exposed to strong sound pulses, possibly 
repeatedly.
    If some cetaceans did incur mild or moderate TTS through exposure 
to airgun sounds in this manner, this would very likely be a temporary 
and reversible phenomenon. However, even a temporary reduction in 
hearing sensitivity could be deleterious in the event that, during that 
period of reduced sensitivity, a marine mammal needed its full hearing 
sensitivity to detect approaching predators, or for some other reason.
    Some pinnipeds show avoidance reactions to airguns, but their 
avoidance reactions are generally not as strong or consistent as those 
of cetaceans. Pinnipeds occasionally seem to be attracted to operating 
seismic vessels. There are no specific data on TTS thresholds of 
pinnipeds exposed to single or multiple low-frequency pulses. However, 
given the indirect indications of a lower TTS threshold for the harbor 
seal than for odontocetes exposed to impulse sound (see above), it is 
possible that some pinnipeds close to a large airgun array could incur 
TTS.
    NMFS currently typically includes mitigation requirements to ensure 
that cetaceans and pinnipeds are not exposed to pulsed underwater noise 
at received levels exceeding, respectively, 180 and 190 dB re 1 
[micro]Pa (rms). The 180/190 dB acoustic criteria were taken from 
recommendations by an expert panel of the High Energy Seismic Survey 
(HESS) Team that performed an assessment on noise impacts by seismic 
airguns to marine mammals in 1997, although the HESS Team recommended a 
180-dB limit for pinnipeds in California (HESS 1999). The 180 and 190 
dB re 1 [mu]Pa (rms) levels have not been considered to be the levels 
above which TTS might occur. Rather, they were 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 in various odontocetes (and probably mysticetes as 
well) unless they are exposed to a sequence of several airgun pulses 
stronger than 190 dB re 1 [mu]Pa (rms). On the other hand, for the 
harbor seal, harbor porpoise, and perhaps some other species, TTS may 
occur upon exposure to one or more airgun pulses whose received level 
equals the NMFS ``do not exceed'' value of 190 dB re 1 [mu]Pa (rms). 
That criterion corresponds to a single-pulse SEL of 175-180 dB re 1 
[mu]Pa\2\-s in typical conditions, whereas TTS is suspected to be 
possible in harbor seals and harbor porpoises with a cumulative SEL of 
~171 and ~164 dB re 1 [mu]Pa\2\-s, respectively.
    It has been shown that most large whales and many smaller 
odontocetes

[[Page 35858]]

(especially the harbor porpoise) show at least localized avoidance of 
ships and/or seismic operations. Even when avoidance is limited to the 
area within a few hundred meters of an airgun array, that should 
usually be sufficient to avoid TTS based on what is currently known 
about thresholds for TTS onset in cetaceans. In addition, ramping up 
airgun arrays, which is standard operational protocol for many seismic 
operators, may allow cetaceans near the airguns at the time of startup 
(if the sounds are aversive) to move away from the seismic source and 
to avoid being exposed to the full acoustic output of the airgun array. 
Thus, most baleen whales likely will not be exposed to high levels of 
airgun sounds provided the ramp-up procedure is applied. Likewise, many 
odontocetes close to the trackline are likely to move away before the 
sounds from an approaching seismic vessel become sufficiently strong 
for there to be any potential for TTS or other hearing impairment. 
Hence, there is little potential for baleen whales or odontocetes that 
show avoidance of ships or airguns to be close enough to an airgun 
array to experience TTS. Nevertheless, even if marine mammals were to 
experience TTS, the magnitude of the TTS is expected to be mild and 
brief, only in a few decibels for minutes.
    PTS:
    When PTS occurs, there is physical damage to the sound receptors in 
the ear. In some cases, there can be total or partial deafness, whereas 
in other cases, the animal has an impaired ability to hear sounds in 
specific frequency ranges (Kryter 1985). Physical damage to a mammal's 
hearing apparatus can occur if it is exposed to sound impulses that 
have very high peak pressures, especially if they have very short rise 
times. (Rise time is the interval required for sound pressure to 
increase from the baseline pressure to peak pressure.)
    There is no specific evidence that exposure to pulses of airgun 
sound can cause PTS in any marine mammal, even with large arrays of 
airguns. However, given the likelihood that some mammals close to an 
airgun array might incur at least mild TTS (see above), there has been 
further speculation about the possibility that some individuals 
occurring very close to airguns might incur PTS (e.g., Richardson et 
al. 1995; Gedamke et al. 2008). Single or occasional occurrences of 
mild TTS are not indicative of permanent auditory damage, but repeated 
or (in some cases) single exposures to a level well above that causing 
TTS onset might elicit PTS.
    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 (Southall et al. 2007). Based on data from 
terrestrial mammals, a precautionary assumption is that the PTS 
threshold for impulse sounds (such as airgun pulses as received close 
to the source) is at least 6 dB higher than the TTS threshold on a 
peak-pressure basis, and probably >6 dB higher (Southall et al. 2007). 
The low-to-moderate levels of TTS that have been induced in captive 
odontocetes and pinnipeds during controlled studies of TTS have been 
confirmed to be temporary, with no measurable residual PTS (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005; Nachtigall 
et al. 2003; 2004). However, very prolonged exposure to sound strong 
enough to elicit TTS, or shorter-term exposure to sound levels well 
above the TTS threshold, can cause PTS, at least in terrestrial mammals 
(Kryter 1985). In terrestrial mammals, the received sound level from a 
single non-impulsive sound exposure must be far above the TTS threshold 
for any risk of permanent hearing damage (Kryter 1994; Richardson et 
al. 1995; Southall et al. 2007). However, there is special concern 
about strong sounds whose pulses have very rapid rise times. In 
terrestrial mammals, there are situations when pulses with rapid rise 
times (e.g., from explosions) can result in PTS even though their peak 
levels are only a few dB higher than the level causing slight TTS. The 
rise time of airgun pulses is fast, but not as fast as that of an 
explosion.
    Some factors that contribute to onset of PTS, at least in 
terrestrial mammals, are as follows:
     Exposure to a single very intense sound,
     Fast rise time from baseline to peak pressure,
     Repetitive exposure to intense sounds that individually 
cause TTS but not PTS, and
     Recurrent ear infections or (in captive animals) exposure 
to certain drugs.
    Cavanagh (2000) reviewed the thresholds used to define TTS and PTS. 
Based on this review and SACLANT (1998), it is reasonable to assume 
that PTS might occur at a received sound level 20 dB or more above that 
inducing mild TTS. However, for PTS to occur at a received level only 
20 dB above the TTS threshold, the animal probably would have to be 
exposed to a strong sound for an extended period, or to a strong sound 
with a rather rapid rise time.
    More recently, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB, on an 
SEL basis, for there to be risk of PTS. Thus, for cetaceans exposed to 
a sequence of sound pulses, they estimate that the PTS threshold might 
be an M-weighted SEL (for the sequence of received pulses) of ~198 dB 
re 1 [mu]Pa\2\-s. Additional assumptions had to be made to derive a 
corresponding estimate for pinnipeds, as the only available data on 
TTS-thresholds in pinnipeds pertained to nonimpulse sound (see above). 
Southall et al. (2007) estimated that the PTS threshold could be a 
cumulative SEL of ~186 dB re 1 [mu]Pa\2\-s in the case of a harbor seal 
exposed to impulse sound. The PTS threshold for the California sea lion 
and northern elephant seal would probably be higher given the higher 
TTS thresholds in those species. Southall et al. (2007) also note that, 
regardless of the SEL, there is concern about the possibility of PTS if 
a cetacean or pinniped received one or more pulses with peak pressure 
exceeding 230 or 218 dB re 1 [mu]Pa, respectively. Thus, PTS might be 
expected upon exposure of cetaceans to either SEL >=198 dB re 1 
[mu]Pa\2\-s or peak pressure >=230 dB re 1 [mu]Pa. Corresponding 
proposed dual criteria for pinnipeds (at least harbor seals) are >=186 
dB SEL and >=218 dB peak pressure (Southall et al. 2007). These 
estimates are all first approximations, given the limited underlying 
data, assumptions, species differences, and evidence that the ``equal 
energy'' model may not be entirely correct.
    Sound impulse duration, peak amplitude, rise time, number of 
pulses, and inter-pulse interval are the main factors thought to 
determine the onset and extent of PTS. Ketten (1994) has noted that the 
criteria for differentiating the sound pressure levels that result in 
PTS (or TTS) are location and species specific. PTS effects may also be 
influenced strongly by the health of the receiver's ear.
    As described above for TTS, in estimating the amount of sound 
energy required to elicit the onset of TTS (and PTS), it is assumed 
that the auditory effect of a given cumulative SEL from a series of 
pulses is the same as if that amount of sound energy were received as a 
single strong sound. There are no data from marine mammals concerning 
the occurrence or magnitude of a potential partial recovery effect 
between pulses. In deriving the estimates of PTS (and TTS) thresholds 
quoted here, Southall et al. (2007) made the precautionary assumption 
that no recovery would occur between pulses.
    It is unlikely that an odontocete would remain close enough to a 
large airgun array for sufficiently long to

[[Page 35859]]

incur PTS. There is some concern about bowriding odontocetes, but for 
animals at or near the surface, auditory effects are reduced by Lloyd's 
mirror and surface release effects. The presence of the vessel between 
the airgun array and bow-riding odontocetes could also, in some but 
probably not all cases, reduce the levels received by bow-riding 
animals (e.g., Gabriele and Kipple 2009). The TTS (and thus PTS) 
thresholds of baleen whales are unknown but, as an interim measure, 
assumed to be no lower than those of odontocetes. Also, baleen whales 
generally avoid the immediate area around operating seismic vessels, so 
it is unlikely that a baleen whale could incur PTS from exposure to 
airgun pulses. The TTS (and thus PTS) thresholds of some pinnipeds 
(e.g., harbor seal) as well as the harbor porpoise may be lower (Kastak 
et al. 2005; Southall et al. 2007; Lucke et al. 2009). If so, TTS and 
potentially PTS may extend to a somewhat greater distance for those 
animals. Again, Lloyd's mirror and surface release effects will 
ameliorate the effects for animals at or near the surface.
(4) 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 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 intense sounds. 
However, there is no definitive evidence that any of these effects 
occur even for marine mammals in close proximity to large arrays of 
airguns, 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.
    Therefore, it is unlikely that such effects would occur during 
SAE's proposed seismic surveys given the brief duration of exposure, 
the small sound sources, and the planned monitoring and mitigation 
measures described later in this document.
    Additional non-auditory effects include elevated levels of stress 
response (Wright et al. 2007; Wright and Highfill 2007). Although not 
many studies have been done on noise-induced stress in marine mammals, 
extrapolation of information regarding stress responses in other 
species seems applicable because the responses are highly consistent 
among all species in which they have been examined to date (Wright et 
al. 2007). Therefore, it is reasonable to conclude that noise acts as a 
stressor to marine mammals. Furthermore, given that marine mammals will 
likely respond in a manner consistent with other species studied, 
repeated and prolonged exposures to stressors (including or induced by 
noise) could potentially be problematic for marine mammals of all ages. 
Wright et al. (2007) state that a range of issues may arise from an 
extended stress response including, but not limited to, suppression of 
reproduction (physiologically and behaviorally), accelerated aging and 
sickness-like symptoms. However, as mentioned above, SAE's proposed 
activity is not expected to result in these severe effects due to the 
nature of the potential sound exposure.
(5) Stranding and Mortality
    Marine mammals close to underwater detonations can be killed or 
severely injured, and the auditory organs are especially susceptible to 
injury (Ketten et al. 1993; Ketten 1995). Airgun pulses are less 
energetic and their peak amplitudes have slower rise times, while 
stranding and mortality events would include other energy sources 
(acoustical or shock wave) far beyond just seismic airguns. To date, 
there is no evidence that serious injury, death, or stranding by marine 
mammals can occur from exposure to airgun pulses, even in the case of 
large airgun arrays.
    However, in numerous past IHA notices for seismic surveys, 
commenters have referenced two stranding events allegedly associated 
with seismic activities, one off Baja California and a second off 
Brazil. NMFS has addressed this concern several times, and, without new 
information, does not believe that this issue warrants further 
discussion. For information relevant to strandings of marine mammals, 
readers are encouraged to review NMFS' response to comments on this 
matter found in 69 FR 74906 (December 14, 2004), 71 FR 43112 (July 31, 
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 
2006).
    It should be noted that strandings related to sound exposure have 
not been recorded for marine mammal species in the Chukchi or Beaufort 
seas. NMFS notes that in the Beaufort and Chukchi seas, aerial surveys 
have been conducted by BOEM (previously MMS) and industry during 
periods of industrial activity (and by BOEM during times with no 
activity). No strandings or marine mammals in distress have been 
observed during these surveys and none have been reported by North 
Slope Borough inhabitants. In addition, there are very few instances 
that seismic surveys in general have been linked to marine mammal 
strandings, other than those mentioned above. As a result, NMFS does 
not expect any marine mammals will incur serious injury or mortality in 
the Arctic Ocean or strand as a result of the proposed marine survey.

Potential Effects of Sonar Signals

    Industrial standard navigational sonars would be used during SAE's 
proposed 3D seismic surveys program for navigation safety. Source 
characteristics of the representative generic equipment are discussed 
in the ``Description of Specific Activity'' section above. In general, 
the potential effects of this equipment on marine mammals are similar 
to those from the airgun, except the magnitude of the impacts is 
expected to be much less due to the lower intensity, higher 
frequencies, and with downward narrow beam patterns. In some cases, due 
to the fact that the operating frequencies of some of this equipment 
(e.g., Kongsberg EA600 with frequencies up to 200 kHz) are above the 
hearing ranges of marine mammals, they are not expected to have any 
impacts to marine mammals.

Vessel Sounds

    In addition to the noise generated from seismic airguns and active 
sonar systems, two vessels would be involved in the operations, 
including a source vessel and a support vessel that provides marine 
mammal monitoring and logistic support. Sounds from boats and vessels 
have been reported extensively (Greene and Moore 1995; Blackwell and 
Greene 2002; 2005; 2006). Numerous measurements of underwater vessel 
sound have been performed in support of recent industry activity in the 
Chukchi and Beaufort Seas. Results of these measurements were reported 
in various 90-day and comprehensive reports since 2007 (e.g., Aerts et 
al. 2008; Hauser et al. 2008; Brueggeman 2009; Ireland et al. 2009; 
O'Neill and McCrodan 2011; Chorney et al. 2011; McPherson and Warner 
2012). For example, Garner and Hannay (2009) estimated sound pressure 
levels of 100 dB at distances ranging from approximately 1.5 to 2.3 mi 
(2.4 to 3.7 km) from various types of barges. MacDonald et al. (2008) 
estimated higher underwater SPLs from the

[[Page 35860]]

seismic vessel Gilavar of 120 dB at approximately 13 mi (21 km) from 
the source, although the sound level was only 150 dB at 85 ft (26 m) 
from the vessel. Compared to airgun 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. Source levels from various vessels would 
be empirically measured before the start of the seismic surveys.

Anticipated Effects on Habitat

    The primary potential impacts to marine mammals and other marine 
species are associated with elevated sound levels produced by airguns 
and vessels operating in the area. However, other potential impacts to 
the surrounding habitat from physical disturbance are also possible.
    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 non-pulse signals (such as noise from vessels) 
(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).
    Further, during the seismic survey only a small fraction of the 
available habitat would be ensonified at any given time. Disturbance to 
fish species would be short-term and fish would return to their pre-
disturbance behavior once the seismic activity ceases (McCauley et al. 
2000a, 2000b; Santulli et al. 1999; Pearson et al. 1992). Thus, the 
proposed survey would have little, if any, impact on the abilities of 
marine mammals to feed in the area where seismic work is planned.
    Some mysticetes, including bowhead whales, feed on concentrations 
of zooplankton. Some feeding bowhead whales may occur in the Alaskan 
Beaufort Sea in July and August, and others feed intermittently during 
their westward migration in September and October (Richardson and 
Thomson [eds.] 2002; Lowry et al. 2004). A reaction by zooplankton to a 
seismic impulse would only be relevant to whales if it caused 
concentrations of zooplankton to scatter. Pressure changes of 
sufficient magnitude to cause that type of reaction would probably 
occur only very close to the source. Impacts on zooplankton behavior 
are predicted to be negligible, and that would translate into 
negligible impacts on feeding mysticetes. Thus, the proposed activity 
is not expected to have any habitat-related effects on prey species 
that could cause significant or long-term consequences for individual 
marine mammals or their populations.

Potential Impacts on Availability of Affected Species or Stock for 
Taking for Subsistence Uses

    Subsistence hunting is an essential aspect of Inupiat Native life, 
especially in rural coastal villages. The Inupiat participate in 
subsistence hunting activities in and around the Beaufort Sea. The 
animals taken for subsistence provide a significant portion of the food 
that will last the community through the year. Marine mammals represent 
on the order of 60-80% of the total subsistence harvest. Along with the 
nourishment necessary for survival, the subsistence activities 
strengthen bonds within the culture, provide a means for educating the 
young, provide supplies for artistic expression, and allow for 
important celebratory events.
    The proposed seismic activities will occur within the marine 
subsistence area used by the village of Nuiqsut. Nuiqsut was 
established in 1973 at a traditional location on the Colville River 
providing equal access to upland (e.g., caribou, Dall sheep) and marine 
(e.g., whales, seals, and eiders) resources (Brown 1979).

Potential Impacts to Subsistence Uses

    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.''
(1) Bowhead Whales
    Ten primary coastal Alaskan villages deploy whaling crews during 
whale migrations. Around SAE's proposed project areas in the Beaufort 
Sea, the primary bowhead hunting villages that could be affected are 
Barrow and Nuiqsut.
    Whaling crews in Barrow hunt in both the spring and the fall (Funk 
and Galginaitis 2005). The primary bowhead whale hunt in Barrow occurs 
during spring, while the fall hunt is used to meet the quota and seek 
strikes that can be transferred from other communities. In the spring, 
the whales are hunted along leads that occur when the pack ice starts 
deteriorating. This tends to occur between the first week of April 
through May in Barrow, well before the proposed 3D OBC seismic survey 
would be conducted. The survey will start after all the ice melts, 
which would occur around mid-July.
    Although Nuiqsut is located 40 km (25 mi) inland, bowhead whales 
are still a major fall subsistence resource. Although bowhead whales 
have been harvested in the past all along the barrier islands, Cross 
Island is the site currently used as the fall whaling base as it 
includes cabins and equipment for butchering whales. However, whalers

[[Page 35861]]

must travel about 160 km (100 mi) annually to reach the Cross Island 
whaling camp which is located over 110 direct km (70 mi) from Nuiqsut. 
Whaling activity usually begins in late August with the arrival of 
whales migrating from the Canadian Beaufort Sea, and may occur as late 
as early October depending on ice conditions and quota fulfillment. 
Most whaling occurs relatively near (<16 km; <10 mi) the island, 
largely to prevent meat spoilage that can occur with a longer tow back 
to Cross Island. Since 1993, Cross Island hunters have harvested one to 
four whales annually, averaging three.
    Cross Island is located 70 km (44 mi) east of the eastern boundary 
of the seismic survey box, while Barrow is located approximately 350 km 
(217 mi) west of the western boundary of the seismic survey box. At 
this far distance, seismic activities are unlikely to affect Barrow or 
Cross Island based whaling, especially if the seismic operations 
temporarily cease during the fall bowhead whale hunt.
(2) Beluga Whales
    Belugas typically do not represent a large proportion of the 
subsistence harvests by weight in the communities of Nuiqsut and 
Barrow. Barrow residents hunt beluga in the spring (normally after the 
bowhead hunt) in leads between Point Barrow and Skull Cliffs in the 
Chukchi Sea primarily in April-June, and later in the summer (July-
August) on both sides of the barrier island in Elson Lagoon/Beaufort 
Sea (MMS 2008), but harvest rates indicate the hunts are not frequent. 
Although Nuiqsut whalers may incidentally harvest beluga whales while 
hunting bowheads, these whales are rarely seen and are not actively 
pursued. Any harvest would occur most likely in association with Cross 
Island.
    For the same reason discussed above, the great distances from 
Barrow and Cross Island to either of the boundaries of the seismic 
survey box prompt NMFS to preliminarily determine that the proposed 
seismic activities would not adversely affect subsistence beluga whale 
hunt.
(3) Seals
    The potential seismic survey area is also used by Nuiqsut villagers 
for hunting seals. All three seal species--ringed, spotted, and 
bearded--are taken. Sealing begins in April and May when villagers hunt 
seals at breathing holes in Harrison Bay. In early June, hunting is 
concentrated at the mouth of the Colville River where ice breakup 
flooding results in the ice thinning and seals becoming more visible. 
Once the ice is clear of the Delta (late June), hunters will hunt in 
open boats along the ice edge from Harrison Bay to Thetis Island in a 
route called ``round the world''. Thetis Island is important as it 
provides a weather refuge and a base for hunting bearded seals. During 
the July and August ringed and spotted seals are hunted in the lower 65 
km (40 mi) of the Colville River proper.
    In terms of pounds, approximately one-third of the village of 
Nuiqsut's annual subsistence harvest is marine mammals (fish and 
caribou dominate the rest), of which bowhead whales contribute by far 
the most (Fuller and George 1999). Seals contribute only 2 to 3 percent 
of annual subsistence harvest (Brower and Opie 1997, Brower and Hepa 
1998, Fuller and George 1999). Fuller and George (1999) estimated that 
46 seals were harvested in 1992. The more common ringed seals appear to 
dominate the harvest although the larger and thicker skinned bearded 
seals are probably preferred. Spotted seals occur in the Colville River 
Delta in small numbers, which is reflected in the harvest.
    Available harvest records suggest that most seal harvest occurs in 
the months preceding the July start of seismic survey when waning ice 
conditions provide the best opportunity to approach and kill hauled out 
seals. Much of the late summer seal harvest occurs in the Colville 
River as the seals follow fish runs upstream. Still, open water seal 
hunting could occur coincident with the seismic surveys, especially 
bearded seal hunts based from Thetis Island. In general, however, given 
the relatively low contribution of seals to the Nuiqsut subsistence, 
and the greater opportunity to hunt seals earlier in the season, the 
seismic survey impact to seal hunting is likely remote. Impacts to seal 
populations in general are also very small.
    As stated earlier, the proposed seismic survey would take place 
between July and October. The timing of the surveys activities would 
mostly avoid any spring hunting activities in Beaufort Sea villages. In 
addition, the proposed seismic surveys would occur in areas great 
distances from the places where subsistence activities occur. 
Therefore, due to the time and spatial separation of SAE's proposed 3D 
seismic surveys and the subsistent harvest by the local communities, it 
is anticipated to have no effects on spring harvesting and little or no 
effects on the occasional summer harvest of beluga whale, subsistence 
seal hunts (ringed and spotted seals are primarily harvested in winter 
while bearded seals are hunted during July-September in the Beaufort 
Sea), or the fall bowhead hunt.
    In addition, SAE has developed and proposes to implement a number 
of mitigation measures (described in the next section) which include a 
proposed Marine Mammal Monitoring and Mitigation Plan (4MP), employment 
of subsistence advisors in the villages, and implementation of a 
Communications Plan (with operation of Communication Centers). SAE has 
also prepared a Plan of Cooperation (POC) under 50 CFR 216.104 Article 
12 of the MMPA that addresses potential impacts on subsistent seal 
hunting activities.
    Finally, to ensure that there will be no conflict from SAE's 
proposed open-water seismic surveys to subsistence activities, SAE 
stated that it will maintain communications with subsistence 
communities via the communication centers (Com and Call Centers) and 
signed the Conflict Avoidance Agreement (CAA) with Alaska whaling 
communities.

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 SAE open-water 3D OBC seismic surveys in the 
Beaufort Sea, SAE 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 marine seismic survey 
activities. The primary purpose of these mitigation measures is to 
detect marine mammals within, or about to enter designated exclusion 
zones and to initiate immediate shutdown or power down of the 
airgun(s), therefore it's very unlikely potential injury or TTS to 
marine mammals would occur, and Level B behavioral of marine mammals 
would be reduced to the lowest level practicable.

(1) Establishing Exclusion and Disturbance Zones

    Under current NMFS guidelines, the ``exclusion zone'' for marine 
mammal exposure to impulse sources is customarily defined as the area 
within which received sound levels are >=180 dB (rms) re 1 [mu]Pa for 
cetaceans and >=190

[[Page 35862]]

dB (rms) re 1 [mu]Pa for pinnipeds. These 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 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 exclusion zones 
(Richarcdson et al. 1995). Currently, NMFS uses 160 dB (rms) re 1 
[mu]Pa as the threshold for Level B behavioral harassment from impulses 
noise.
    As discussed above, the acoustic propagation of the proposed 440-
in\3\, 880-in\3\, and 1,760-in\3\ airgun arrays were predicted using 
JASCO's model provided in Aerts et al. (2008), corrected with the 
measured or manufacture's source levels. The resulting isopleths 
modeled for the 190, 180, and 160 dB (rms) re 1 [mu]Pa exclusion zones 
and zones of influence are listed in Table 2.
    These safety distances will be implemented at the commencement of 
2013 airgun operations to establish marine mammal exclusion zones used 
for mitigation. SAE will conduct sound source measurements of the 
airgun array at the beginning of survey operations in 2013 to verify 
the size of the various marine mammal exclusion zones. The acoustic 
data will be analyzed as quickly as reasonably practicable in the field 
and used to verify and adjust the marine mammal exclusion zone 
distances. The mitigation measures to be implemented at the 190 and 180 
dB (rms) sound levels will include power downs and shut downs as 
described below.

(2) Vessel Related Mitigation Measures

    This proposed mitigation measures apply to all vessels that are 
part of the Beaufort Sea seismic survey activities, including 
supporting vessels.
     Avoid concentrations or groups of whales by all vessels 
under the direction of SAE. Operators of vessels should, at all times, 
conduct their activities at the maximum distance possible from such 
concentrations of whales.
     Vessels in transit shall be operated at speeds necessary 
to ensure no physical contact with whales occurs. If any vessel 
approaches within 1.6 km (1 mi) of observed bowhead whales, except when 
providing emergency assistance to whalers or in other emergency 
situations, the vessel operator will take reasonable precautions to 
avoid potential interaction with the bowhead whales by taking one or 
more of the following actions, as appropriate:
    [cir] Reducing vessel speed to less than 5 knots within 300 yards 
(900 feet or 274 m) of the whale(s);
    [cir] Steering around the whale(s) if possible;
    [cir] Operating the vessel(s) in such a way as to avoid separating 
members of a group of whales from other members of the group;
    [cir] Operating the vessel(s) to avoid causing a whale to make 
multiple changes in direction; and
    [cir] Checking the waters immediately adjacent to the vessel(s) to 
ensure that no whales will be injured when the propellers are engaged.
     When weather conditions require, such as when visibility 
drops, adjust vessel speed accordingly to avoid the likelihood of 
injury to whales.

(3) Mitigation Measures for Airgun Operations

    The primary role for airgun mitigation during the seismic surveys 
is to monitor marine mammals near the airgun array during all daylight 
airgun operations and during any nighttime start-up of the airguns. 
During the seismic surveys PSOs will monitor the pre-established 
exclusion zones for the presence of marine mammals. When marine mammals 
are observed within, or about to enter, designated safety zones, PSOs 
have the authority to call for immediate power down (or shutdown) of 
airgun operations as required by the situation. A summary of the 
procedures associated with each mitigation measure is provided below.
Ramp Up Procedure
    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of airguns firing until the full volume is achieved. The purpose 
of a ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds 
in the vicinity of the airguns and to provide time for them to leave 
the area and thus avoid any potential injury or impairment of their 
hearing abilities.
    During the proposed open-water survey program, the seismic operator 
will ramp up the airgun arrays 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 (i.e., the mitigation airgun). A 
full ramp up, after a shut down, will not begin until there has been a 
minimum of 30 min of observation of the safety zone by PSOs to assure 
that no marine mammals are present. The entire exclusion zone must be 
visible during the 30-minute lead-in to a full ramp up. If the entire 
exclusion zone is not visible, then ramp up from a cold start cannot 
begin. If a marine mammal(s) is sighted within the 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 exclusion zone or the 
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for 
small odontocetes (harbor porpoise) and pinnipeds, or 30 minutes for 
baleen whales and large odontocetes (including beluga and killer whales 
and narwhal).
Use of a Small-Volume Airgun During Turns and Transits
    Throughout the seismic survey, particularly during turning 
movements, and short transits, SAE will employ the use of the smallest 
volume airgun (i.e., ``mitigation airgun'') to deter marine mammals 
from being within the immediate area of the seismic operations. The 
mitigation airgun would be operated at approximately one shot per 
minute and would not be operated for longer than three hours in 
duration (turns may last two to three hours for the proposed project).
    During turns or brief transits (e.g., less than three hours) 
between seismic tracklines, one mitigation airgun will continue 
operating. The ramp-up procedure will still be followed when increasing 
the source levels from one airgun to the full airgun array. However, 
keeping one airgun firing will avoid the prohibition of a ``cold 
start'' during darkness or other periods of poor visibility. Through 
use of this approach, seismic surveys using the full array may resume 
without the 30 minute observation period of the full exclusion zone 
required for a ``cold start''. PSOs will be on duty whenever the 
airguns are firing during daylight, during the 30 minute periods prior 
to ramp-ups.
Power-Down and Shut-Down Procedures
    A power down is the immediate reduction in the number of operating 
energy sources from all firing to some smaller number (e.g., single 
mitigation airgun). A shut down is the immediate cessation of firing of 
all energy sources. 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 source. If a marine mammal is 
sighted within or about to enter the applicable safety zone of the 
single mitigation airgun, the entire array will be shut down (i.e., no 
sources firing).

[[Page 35863]]

Poor Visibility Conditions
    SAE plans to conduct 24-hour operations. PSOs will not be on duty 
during ongoing seismic operations during darkness, given the very 
limited effectiveness of visual observation at night (there will be no 
periods of darkness in the survey area until mid-August). The proposed 
provisions associated with operations at night or in periods of poor 
visibility include the following:
     If during foggy conditions, heavy snow or rain, or 
darkness (which may be encountered starting in late August), the full 
180 dB exclusion zone is not visible, the airguns cannot commence a 
ramp-up procedure from a full shut-down.
     If one or more airguns have been operational before 
nightfall or before the onset of poor visibility conditions, they can 
remain operational throughout the night or poor visibility conditions. 
In this case ramp-up procedures can be initiated, even though the 
exclusion zone may not be visible, on the assumption that marine 
mammals will be alerted by the sounds from the single airgun and have 
moved away.

(4) Mitigation Measures for Subsistence Activities

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a Plan of 
Cooperation (POC) or information that identifies what measures have 
been taken and/or will be taken to minimize adverse effects on the 
availability of marine mammals for subsistence purposes.
    SAE has prepared a draft POC, which was developed based on 
identifying and evaluating any potential effects on seasonal abundance 
that is relied upon for subsistence use. For the proposed project SAE 
states that it will work closely with the North Slope Borough (NSB) and 
its partner Kuukpik Corporation, to identify subsistence communities 
and activities that may take place within or near the project area.
    The scheduling of seismic activities will be discussed with 
representatives of all those concerned with the subsistence hunts. SAE 
presented the seismic project at the Alaska Eskimo Whaling Commission 
(AEWC) conference in December 2012 in Anchorage, Alaska. SAE also had 
presented the project at the open-water meeting in March 2013 in 
Anchorage, Alaska.
    In addition, SAE plans to hold additional meeting(s) the NSB and 
the villages of Nuiqsut, Barrow, and Kaktovik to discuss the proposed 
activities and monitoring and mitigation plans to minimize impacts. 
These discussions are scheduled for June/July and will include:
     A description of the proposed marine seismic survey, 
documentation of the crew's activities;
     documentation of consultation with local communities and 
tribal governments;
     project maps showing project boundaries;
     ongoing scheduling updates for information on the 
subsistence marine activities; and
     a plan for meetings and communication with post project 
subsistence communities.
    A final POC that documents all meetings and consultations with 
community leaders and subsistence users will be submitted to NMFS.
    In addition, SAE is planning to sign a CAA with the Alaska whaling 
communities to further ensure that its proposed open-water seismic 
survey activities in the Beaufort Sea will not have unmitigable impacts 
to subsistence activities. NMFS has included appropriate measures 
identified in the CAA in the IHA.
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; 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.

I. Proposed Monitoring Measures

    The monitoring plan proposed by SAE is included in its IHA 
application and can be found in its Marine Mammal Monitoring and 
Mitigation Plan (4MP). 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.
    Monitoring will provide information on the numbers of marine 
mammals potentially affected by the exploration operations and 
facilitate real time mitigation to prevent injury of marine mammals by 
industrial sounds or activities. These goals will be accomplished in 
the Beaufort Sea during 2013 by conducting vessel-based monitoring from 
both source vessels and the mitigation vessel and an acoustic 
monitoring program using a bottom-mounted hydrophone array to document 
marine mammal presence and distribution in the vicinity of the survey 
area.
    Visual monitoring by Protected Species Observers (PSOs) during 
active marine survey operations, and periods when these surveys are not 
occurring, will provide information on the numbers of marine mammals 
potentially affected by these activities and facilitate real time 
mitigation to prevent impacts to marine mammals by industrial sounds or 
operations. Vessel-based PSOs onboard the survey vessels and mitigation 
vessel will record the numbers and species of marine mammals observed 
in the area and any observable reaction of marine mammals to the survey 
activities in the Beaufort Sea.

Visual-Based Protected Species Observers (PSOs)

    The visual-based marine mammal monitoring will be implemented by a 
team of experienced PSOs, including both biologists and Inupiat 
personnel. PSOs will be stationed aboard the survey vessels and 
mitigation vessel through the duration of the project. The vessel-based 
marine mammal monitoring will provide the basis for

[[Page 35864]]

real-time mitigation measures as discussed in the Proposed Mitigation 
section. In addition, monitoring results of the vessel-based monitoring 
program will include the estimation of the number of ``takes'' as 
stipulated in the IHA.

(1) Protected Species Observers

    Vessel-based monitoring for marine mammals will be done by trained 
PSOs throughout the period of survey activities. The observers will 
monitor the occurrence of marine mammals near the survey vessel during 
all daylight periods during operation, and during most daylight periods 
when 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''.
    A sufficient number of PSOs will be required onboard the survey 
vessel to meet the following criteria:
     100% monitoring coverage during all periods of survey 
operations in daylight;
     maximum of 4 consecutive hours on watch per PSO; and
     maximum of 12 hours of watch time per day per PSO.
    PSO teams will consist of Inupiat observers and experienced field 
biologists. Each vessel will have an experienced field crew leader to 
supervise the PSO team. The total number of PSOs may decrease later in 
the season as the duration of daylight decreases.

(2) Observer Qualifications and Training

    Crew leaders and most PSOs will be individuals with experience as 
observers during recent seismic, site clearance and shallow hazards, 
and other monitoring projects in Alaska or other offshore areas in 
recent years.
    Biologist-observers will have previous marine mammal observation 
experience, and field crew leaders will be highly experienced with 
previous vessel-based marine mammal monitoring and mitigation projects. 
Resumes for those individuals will be provided to NMFS for review and 
acceptance of their qualifications. Inupiat observers will be 
experienced in the region and familiar with the marine mammals of the 
area. All observers will complete a NMFS-approved observer training 
course designed to familiarize individuals with monitoring and data 
collection procedures.
    PSOs will complete a two or three-day training and refresher 
session on marine mammal monitoring, to be conducted shortly before the 
anticipated start of the 2013 open-water season. Any exceptions will 
have or receive equivalent experience or training. The training 
session(s) will be conducted by qualified marine mammalogists with 
extensive crew-leader experience during previous vessel-based seismic 
monitoring programs.

(3) Marine Mammal Observer Protocol

    The PSOs will watch for marine mammals from the best available 
vantage point on the survey vessels, typically the bridge. The PSOs 
will scan systematically with the unaided eye and 7 x 50 reticle 
binoculars, supplemented with 20 x 60 image-stabilized binoculars or 25 
x 150 binoculars, and night-vision equipment when needed. Personnel on 
the bridge will assist the marine mammal observer(s) in watching for 
marine mammals.
    The observer(s) aboard the survey and mitigation vessels will give 
particular attention to the areas within the marine mammal exclusion 
zones around the source vessel. These zones are the maximum distances 
within which received levels may exceed 180 dB (rms) re 1 [mu]Pa (rms) 
for cetaceans, or 190 dB (rms) re 1 [mu]Pa for pinnipeds.
    Distances to nearby marine mammals will be estimated with 
binoculars (7 x 50 binoculars) containing a reticle to measure the 
vertical angle of the line of sight to the animal relative to the 
horizon. Observers may use a laser rangefinder to test and improve 
their abilities for visually estimating distances to objects in the 
water.
    When a marine mammal is seen approaching or within the exclusion 
zone applicable to that species, the marine survey crew will be 
notified immediately so that mitigation measures called for in the 
applicable authorization(s) can be implemented.
    Night-vision equipment (Generation 3 binocular image intensifiers 
or equivalent units) will be available for use when/if needed. Past 
experience with night-vision devices (NVDs) in the Beaufort Sea and 
elsewhere has indicated that NVDs are not nearly as effective as visual 
observation during daylight hours (e.g., Harris et al. 1997, 1998; 
Moulton and Lawson 2002).

Pinniped Surveys Before, During and After Seismic Surveys

    SAE will also conduct a pinniped survey in the proposed seismic 
survey area before, during, and after the seismic surveys to provide a 
basis for determining whether ringed and bearded seals alter their 
habitat use patterns during the seismic survey. At the moment, SAE is 
in the process of developing a survey design using a combination of 
shipboard and aerial survey of the seismic survey block. This design 
will focus on resident ringed and spotted seals, spotted seal haul out 
use in the Colville River delta, and migrating and perhaps resident 
bearded seals. Both vessels and aircraft surveys will follow standard 
line transect methods.

Field Data-Recording

    The PSOs aboard the vessels will maintain a digital log of seismic 
surveys, noting the date and time of all changes in seismic activity 
(ramp-up, power-down, changes in the active seismic source, shutdowns, 
etc.) and any corresponding changes in monitoring radii in a project-
customized Mysticetus\TM\ observation software spreadsheet. In 
addition, PSOs will utilize this standardized format to record all 
marine mammal observations and mitigation actions (seismic source 
power-downs, shut-downs, and ramp-ups). Information collected during 
marine mammal observations will include the following:
     Vessel speed, position, and activity
     Date, time, and location of each marine mammal sighting
     Number of marine mammals observed, and group size, sex, 
and age categories
     Observer's name and contact information
     Weather, visibility, and ice conditions at the time of 
observation
     Estimated distance of marine mammals at closest approach
     Activity at the time of observation, including possible 
attractants present
     Animal behavior
     Description of the encounter
     Duration of encounter
     Mitigation action taken
    Data will preferentially be recorded directly into handheld 
computers or as a back-up, transferred from hard-copy data sheets into 
an electronic database. A system for quality control and verification 
of data will be facilitated by the pre-season training, supervision by 
the lead PSOs, in-season data checks. Computerized data validity checks 
will also be conducted, and the data will be managed in such a way that 
it is easily summarized during and after the field program and 
transferred into statistical, graphical, or other programs for further 
processing.

Passive Acoustic Monitoring

(1) Sound Source Measurements

    Prior to or at the beginning of the seismic survey, sound levels 
will be measured as a function of distance and direction from the 
proposed seismic

[[Page 35865]]

source array (full array and reduced to a single mitigation airgun). 
Results of the acoustic characterization and SSV will be used to 
empirically refine the modeled distance estimates of the pre-season 190 
dB, 180 dB, and 160 dB isopleths. The refined SSV exclusion zones will 
be used for the remainder of the seismic survey. Distance estimates for 
the 120 dB isopleth will also be modeled. The results of the SSV will 
be submitted to NMFS within five days after completing the 
measurements, followed by a report in 14 days. A more detailed report 
will be provided to NMFS as part of the 90-day report following 
completion of the acoustic program.

(2) Passive Acoustic Monitoring Using Bottom-Mounted Hydrophones

    SAE also plans to contract a hydroacoustic firm to conduct passive 
acoustic monitoring (PAM) with bottom-mounted hydrophones. The exact 
PAM methodology will depend on the firm selected, and the coordination 
that can be established with existing acoustical monitoring programs, 
but it will involve strategically placing bottom-anchored receivers 
near the survey area. The purpose will be to record seismic noise 
levels and marine mammal vocalizations before, during, and after the 
seismic survey. The PAM will provide additional information on marine 
mammal distribution and movement beyond what are observed by PSOs 
during the proposed seismic survey.
Monitoring Plan Peer Review
    The MMPA requires that monitoring plans be independently peer 
reviewed ``where the proposed activity may affect the availability of a 
species or stock for taking for subsistence uses'' (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 
regulations state, ``Upon receipt of a complete monitoring plan, and at 
its discretion, [NMFS] will either submit the plan to members of a peer 
review panel for review or within 60 days of receipt of the proposed 
monitoring plan, schedule a workshop to review the plan'' (50 CFR 
216.108(d)).
    NMFS convened an independent peer review panel to review SAE's 
mitigation and monitoring plan in its IHA application for taking marine 
mammals incidental to the proposed open-water marine surveys and 
equipment recovery and maintenance in the Beaufort Sea during 2013. The 
panel initially met on January 8 and 9, 2013, in Seattle, Washington. 
However, the panel decided that SAE's IHA application and its 4MP did 
not contain adequate information for the panel to provide meaningful 
recommendations. After SAE revised its IHA application with additional 
information, on April 29, 2013, NMFS convened a new 2-person panel to 
conduct additional review of SAE's 4MP. Both panel members provided 
their final reports to NMFS in May 2013. The reports from both panel 
members can be viewed at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    NMFS provided the panel with SAE's monitoring and mitigation plan 
and asked the panel to address the following questions and issues for 
SAE's plan:
     Will the applicant's stated objectives effectively further 
the understanding of the impacts of their activities on marine mammals 
and otherwise accomplish the goals stated below? If not, how should the 
objectives be modified to better accomplish the goals above?
     Can the applicant achieve the stated objectives based on 
the methods described in the plan?
     Are there technical modifications to the proposed 
monitoring techniques and methodologies proposed by the applicant that 
should be considered to better accomplish their stated objectives?
     Are there techniques not proposed by the applicant (i.e., 
additional monitoring techniques or methodologies) that should be 
considered for inclusion in the applicant's monitoring program to 
better accomplish their stated objectives?
     What is the best way for an applicant to present their 
data and results (formatting, metrics, graphics, etc.) in the required 
reports that are to be submitted to NMFS (i.e., 90-day report and 
comprehensive report)?
    The peer review panel reports contain recommendations that the 
panel members felt were applicable to SAE's monitoring plans. The panel 
agrees that the objective of vessel-based monitoring to implement 
mitigation measures to prevent or limit Level A takes is appropriate. 
In addition, at the time the panel reviewed SAE's proposed marine 
mammal monitoring and mitigation plan, SAE only proposed vessel-based 
visual monitoring, and there was no pinniped survey being proposed to 
document pinniped habitat usage before, during, and after the seismic 
surveys.
    Specific recommendations provided by the peer review panel to 
enhance marine mammal monitoring and information sharing include:
    (1) Passive acoustic monitoring for marine mammals in their study 
area before, during, and after operations to provide further 
understanding of the spatiotemporal distribution and acoustics of the 
marine mammal community in the area, and to provide a method of far-
field monitoring;
    (2) pinniped survey in the proposed seismic survey area before, 
during, and after the seismic surveys to provide a basis for 
determining whether ringed and bearded seals alter their habitat use 
patterns during the seismic survey;
    (3) consultation and coordination with other oil and gas companies 
and with federal, state, and borough agencies to ensure that they have 
the most up-to-date information and can take advantage of other 
monitoring efforts; and
    (4) providing a database of the information collected, plus a 
number of summary analyses and graphics to help NMFS assess the 
potential impacts of their survey. Specific summaries/analyses/graphics 
would include:
     Sound verification results including isopleths of sound 
pressure levels plotted geographically;
     A table or other summary of survey activities (i.e., did 
the survey proceed as planned);
     A table of sightings by time, location, species, and 
distance from the survey vessel;
     A geographic depiction of sightings for each species by 
area and month;
     A table and/or graphic summarizing behaviors observed by 
species;
     A table and/or graphic summarizing observed responses to 
the survey by species;
     A table of mitigation measures (e.g., powerdowns, 
shutdowns) taken by date, location, and species;
     A graphic of sightings by distance for each species and 
location;
     A table or graphic illustrating sightings during the 
survey versus sightings when the airguns were silent; and
     A summary of times when the survey was interrupted because 
of interactions with marine mammals.
    NMFS worked with SAE on implementing the panel members' 
recommendations and suggestions. As a result, SAE agreed that all the 
above recommendations are reasonable and can be incorporated into its 
4MP, and be included in the monitoring and mitigation measures.

II. Reporting Measures

Sound Source Verification Reports
    A report on the preliminary results of the sound source 
verification measurements, including the measured 190, 180, and 160 dB 
(rms) radii of the airgun sources, would be submitted

[[Page 35866]]

within 14 days after collection of those measurements at the start of 
the field season. This report will specify the distances of the 
exclusion zones that were adopted for the survey.
Technical Reports
    The results of SAE's 2013 vessel-based monitoring, including 
estimates of ``take'' by harassment, would be presented in the ``90-
day'' and Final Technical reports, if the IHA is issued. The Technical 
Reports should be submitted to NMFS within 90 days after the end of the 
seismic survey. The Technical Reports 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) To better assess impacts to marine mammals, data analysis 
should be separated into periods when a seismic airgun array (or a 
single mitigation airgun) is operating and when it is not. Final and 
comprehensive reports to NMFS should summarize and plot:
     Data for periods when a seismic array is active and when 
it is not; and
     The respective predicted received sound conditions over 
fairly large areas (tens of km) around operations;
    (e) sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability), such as:
     Initial sighting distances versus airgun activity state;
     Closest point of approach versus airgun activity state;
     Observed behaviors and types of movements versus airgun 
activity state;
     Numbers of sightings/individuals seen versus airgun 
activity state;
     Distribution around the survey vessel versus airgun 
activity state; and
     Estimates of take by harassment;
    (f) Reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable;
    (g) Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available;
    (h) The report should clearly compare authorized takes to the level 
of actual estimated takes; and
    (i) Methodology used to estimate marine mammal takes and relative 
abundance on towed PAM.
Notification of Injured or Dead Marine Mammals
    In addition, NMFS would require SAE to notify NMFS' Office of 
Protected Resources and NMFS' Stranding Network within 48 hours of 
sighting an injured or dead marine mammal in the vicinity of marine 
survey operations. SAE shall provide NMFS with the species or 
description of the animal(s), the condition of the animal(s) (including 
carcass condition if the animal is dead), location, time of first 
discovery, observed behaviors (if alive), and photo or video (if 
available).
    In the event that an injured or dead marine mammal is found by SAE 
that is not in the vicinity of the proposed open-water marine survey 
program, SAE would report the same information as listed above as soon 
as operationally feasible to NMFS.

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 open water marine 
survey program. Anticipated impacts to marine mammals are associated 
with noise propagation from the survey airgun(s) used in the seismic 
surveys.
    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 open water marine survey programs 
might include one or more of the following: 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) is highly unlikely to occur based on 
the proposed mitigation and monitoring measures that would preclude 
marine mammals from being exposed to noise levels high enough to cause 
hearing impairment.
    For impulse sounds, such as those produced by airgun(s) used in the 
3D OBC seismic surveys, NMFS uses the 160 dB (rms) re 1 [mu]Pa isopleth 
to indicate the onset of Level B harassment. SAE provided calculations 
for the 160-dB isopleths produced by the proposed seismic surveys and 
then used those isopleths to estimate takes by harassment. NMFS used 
the calculations to make the necessary MMPA preliminary findings. SAE 
provided a full description of the methodology used to estimate takes 
by harassment in its IHA application, which is also provided in the 
following sections.

Basis for Estimating ``Take by Harassment''

    The estimate of the numbers of each species of marine mammals that 
could be ``taken'' by exposure to OBC seismic survey noise levels is 
determined by multiplying the maximum seasonal density of each species 
by the area that will be ensonified by greater than 160 dB (rms) re 1 
[mu]Pa.
    The areas ensonified by NMFS current Level B harassment exposure 
guideline levels was determined by assuming that the entire survey area 
is ensonified (given that the distance to the 160 dB isopleth during 
seismic survey is greater than the distance spacing between seismic 
source lines), plus a buffer area around the survey box corresponding 
to the distance to the 160 dB isopleth. The estimated distance to the 
160 dB isopleth is 3 km (1.86 mi) based on a sound source of 236.55 dB 
(rms) re 1 [mu]Pa for the 1,760-in\3\ seismic array and JASCO's 
spreading model of 18 log r + 0.0047 estimated for similar Beaufort 
nearshore waters (BP Liberty) by Aerts et al. (2008). Placing a 3 km 
buffer around the 995 km\2\ (384 mi\2\) seismic source area expands the 
ensonification (or Zone of Influence [ZOI]) area to approximately 1,476 
km\2\ (570 mi\2\).
    Within the 1,476 km\2\ ensonified area, 10 percent (148 km\2\) 
falls within the 0 to 1.5 m depth range, 25 percent (362 km\2\) falls 
within the 1.5 to 5 m depth

[[Page 35867]]

range, 54 percent (793 km\2\) with the 5 to 15 m depth range, and 12 
percent (177 km\2\) within waters greater than 15 m deep (bowhead 
migration corridor).

Marine Mammal Density Estimates

    Density estimates were derived for bowhead whales, beluga whales, 
ringed seals, spotted seals, and bearded seals as described below. 
There are no available Beaufort Sea density estimates for gray whales, 
or extralimital species such as humpback whales, narwhals, and ribbon 
seals.
    Bowhead Whale:
    Summer density estimates for bowhead whales are based on surveys 
conducted by Brandon et al. (2011) in Harrison Bay during July and 
August of 2010. Their estimate, corrected for observer and availability 
bias (Thomas et al. 2002), was 0.004 whales per square kilometer. A 
maximum density (0.016/km\2\) was derived by multiplying this value by 
4 to account for variability.
    Fall density estimates were based on Clarke and Ferguson's (2010) 
summarization of the 2000-2009 Bowhead Whale Aerial Survey Program 
(BWASP) conducted annually by the Bureau of Ocean and Energy Management 
(BOEM). The center of the potential survey box occurs between 150\0\ 
and 151\0\ longitude, and the survey area occurs in waters between 1 
and 20 meters deep. Based on these same locations and water depths, 
LAMA Ecological and OASIS Environmental (2011) applied Thomas et al.'s 
(2002) bias correction factors to the number of whales and transect 
survey effort from September (96 animals, 9,933 km) and October (42 
animals, 6,143 km) summarized in Clarke and Ferguson (2010) and 
calculated a September density of 0.1381 whales/km\2\ and an October 
density of 0.0977 whales/km\2\. LAMA Ecological and OASIS Environmental 
(2011) also derived a mean density (0.1226 whales/km\2\) by averaging 
the September and October densities, and used the higher September 
value as the maximum density. Recognizing the validity of this 
approach, these same values are used in the calculations for this 
proposed IHA.
    Beluga Whale:
    The best data available for estimating summer beluga whale 
densities in the Alaskan Beaufort Sea is from Moore et al. (2000) based 
on aerial survey data collected 1982-1986. The best fall data is from 
Clarke et al.'s (2011) compilation of beluga records collected during 
the 2006-2008 BWASP surveys. Using these sighting records (summer 9; 
fall 7) and associated survey effort (summer 7,447 mi; fall 8,808 mi), 
average group size (summer 1.63, fall 2.9), and f(0) and g(0) values 
from Harwood et al. (1996), Shell Offshore, Inc. (2011), estimated 
summer and fall average density values for nearshore Beaufort Sea 
belugas. The estimates were multiplied by 4 to derive a maximum 
density.
    Ringed Seal:
    Surveys for ringed seals have been recently conducted in the 
Beaufort Sea by Kingsley (1986), Frost et al. (2002), Moulton and 
Lawson (2002), Green and Negri (2005), and Green et al. (2006, 2007). 
The shipboard monitoring surveys by Green and Negri (2005) and Green et 
al. (2006, 2007) were not systematically based, but are useful in 
estimating the general composition of pinnipeds in the Beaufort 
nearshore, including the Colville River Delta. Frost et al.'s aerial 
surveys were conducted during ice coverage and don't fully represent 
the summer and fall conditions under which the Beaufort surveys will 
occur. Moulton and Lawson (2002) conducted summer shipboard-based 
surveys for pinnipeds along the nearshore Beaufort Sea coast and 
developed seasonal average and maximum densities representative of 
SAE's Beaufort summer seismic project, while the Kingsley (1986) 
conducted surveys along the ice margin representing fall conditions.
    Spotted Seal:
    Green and Negri (2005) and Green et al. (2006, 2007) recorded 
pinnipeds during barging activity between West Dock and Cape Simpson, 
and found high numbers of ringed seal in Harrison Bay, and peaks in 
spotted seal numbers off the Colville River Delta where a haulout site 
is located. Approximately 5% of all phocid sightings recorded by Green 
and Negri (2005) and Green et al. (2006, 2007) were spotted seals, 
which provide a suitable estimate of the proportion of ringed seals 
versus spotted seals in the Colville River Delta and Harrison Bay. 
Thus, the estimated densities of spotted seals in the seismic survey 
area were derived by multiplying the ringed seal densities from Moulton 
and Lawson (2002) and Kingsley (1986) by 0.05.
    Bearded Seal:
    Bearded seals were also recorded in Harrison Bay and the Colville 
River Delta by Green and Negri (2005) and Green et al. (2006, 2007), 
but at lower proportions to ringed seals than spotted seals. However, 
estimating bearded seal densities based on the proportion of bearded 
seals observed during the barge-based surveys results in density 
estimates that appear unrealistically low given density estimates from 
other studies, especially given that nearby Thetis Island is used as a 
base for annually hunting this seal (densities are seasonally high 
enough for focused hunting). For protective purposes, the bearded seal 
density values used in this application are derived from Stirling et 
al.'s (1982) observations that the proportion of eastern Beaufort Sea 
bearded seals is 5 percent that of ringed seals, similar as was done 
for spotted seals.

Exposure Calculation Methods

    The estimated potential harassment take of local marine mammals by 
SAE's Beaufort seismic project was determined by multiplying the animal 
densities with the area ensonified by seismic-generated noise greater 
than 160 dB (rms) re 1 [mu]Pa that constitutes habitat for each 
respective species. For pinnipeds, which occupy all water depths, this 
includes the entire seismic survey area plus the additional 3 km (1.86 
mi) buffer of noise exceeding 160 dB, or 1,476 km\2\ (570 mi\2\).
    Although the vast majority of bowhead whales migrate through the 
Beaufort sea in waters greater than 15 m (50 ft) deep (Miller et al. 
2002), feeding and migrating bowheads have been found in waters as 
shallow as 5 m (16 ft) (Clarke et al. 2011). Thus, the seismic survey 
area potentially inhabitable by bowhead whales is all waters greater 
than 5 m deep. This area, including the 3 km buffer, is 970 km\2\ (375 
mi\2\).
    Beluga whales have been observed inside the barrier islands where 
they would have to traverse water depths as low as 1.8 meters, but 
these whales are unlikely to inhabit the shallowest water (<1.5 m deep) 
inside the barrier islands where stranding risk can be high. Therefore, 
the area of beluga habitat potentially ensonified (>160 dB) by the 
seismic operations is the waters greater than 1.5 m (5 ft) deep with 
the 3 km buffer, or approximately 1,332 km\2\ (514 mi\2\).
    Bowhead whale take estimates were calculated both for waters >5 and 
>15 m deep. Because the seismic surveys are expected to be operating 5 
to 8 km south of the edge of the migration corridor by the time the 
fall migration commences, the fall exposure numbers (fall maximum of 24 
whales) for waters greater than 15 m deep do not apply, and should be 
subtracted from the exposure estimate for waters greater than 5 m deep 
leaving an exposure estimate of 110 whales. However, even this fall 
maximum estimate is likely very protective given the fall density 
estimate is skewed by higher whale numbers in the deeper waters.
    The take estimates also include species in which the estimated 
exposure is zero, but for which records for the

[[Page 35868]]

Alaskan Beaufort Sea occur (i.e., humpback whale, gray whale, narwhal, 
and ribbon seal).
    The take estimates also do not account for mitigation measures that 
will be implemented including shutting down operations during the fall 
bowhead hunt (thereby avoiding any noise exposure during the peak of 
fall bowhead whale migration) and completing the seismic survey in 
waters greater than 15 m (50 ft) deep in August (thereby avoiding 
seismic survey within the bowhead whale migration corridor after the 
fall hunt). These measures, coupled with ramping up of airguns, should 
reduce the estimated take from seismic survey operations.

Potential Number of ``Take by Harassment''

    As stated earlier, the estimates of potential Level B takes of 
marine mammals by noise exposure are based on a consideration of the 
number of marine mammals that might be present during operations in the 
Beaufort Sea and the anticipated area exposed to those sound pressure 
levels (SPLs) above 160 dB re 1 [micro]Pa for impulse sources (seismic 
airgun during 3D seismic surveys).

   Table 3--Estimated Take of Marine Mammals From the Proposed SAE's 3D OBC Seismic Survey in the Beaufort Sea
                                          During 2013 Open-Water Season
----------------------------------------------------------------------------------------------------------------
                                                                     Estimated                        Percent
              Species                         Population               take          Abundance      population
----------------------------------------------------------------------------------------------------------------
Bowhead whale......................  Bering-Chukchi-Beaufort....             126          10,545            1.19
Gray whale.........................  Eastern North Pacific......               2          19,126            0.01
Humpback whale.....................  Western North Pacific......               2             939            0.21
Beluga whale.......................  Beaufort Sea...............              35          39,258            0.09
Narwhal............................  Baffin Bay.................               2          45,000           0.004
Ringed seal........................  Alaska.....................           3,476         208,857            1.71
Bearded seal.......................  Alaska.....................             179         250,000            0.07
Spotted seal.......................  Alaska.....................             179          59,214            0.30
Ribbon seal........................  Alaska.....................               2          49,000           0.004
----------------------------------------------------------------------------------------------------------------

Estimated Take Conclusions

    Effects on marine mammals are generally expected to be restricted 
to avoidance of the area around the planned activities and short-term 
changes in behavior, falling within the MMPA definition of ``Level B 
harassment''.
    Cetaceans--The take calculation estimates suggest a total of 126 
bowhead whales may be exposed to sounds at or above 160 dB (rms) re 1 
[micro]Pa (Table 3). This number is approximately 1.19% of the Bering-
Chukchi-Beaufort (BCB) population of 10,545 assessed in 2001 (Allen and 
Angliss 2011) and is assuming to be increasing at an annual growth rate 
of 3.4% (Zeh and Punt 2005), which is supported by a 2004 population 
estimate of 12,631 by Koski et al. (2010). The total estimated number 
of beluga whales that may be exposed to sounds from the activities is 
35 (Table 3). The small numbers of other whale species that may occur 
in the Beaufort Sea are unlikely to be present around the planned 
operations but chance encounters may occur. The few individuals would 
represent a very small proportion of their respective populations.
    Pinnipeds--Ringed seal is by far the most abundant species expected 
to be encountered during the planned operations. The best estimate of 
the numbers of ringed seals exposed to sounds at the specified received 
levels during the planned activities is 3,476, which represent up to 
1.71% of the Alaska population. Fewer individuals of other pinniped 
species are estimated to be exposed to sounds at Level B behavioral 
harassment level, also representing small proportions of their 
populations (Table 3).
Negligible Impact and Small Numbers Analysis and Preliminary 
Determination
    As a preliminary matter, we typically include our negligible impact 
and small numbers analysis and determination under the same section 
heading of our Federal Register Notices. Despite co-locating these 
terms, we acknowledge that negligible impact and small numbers are 
distinct standards under the MMPA and treat them as such. The analysis 
presented below does not conflate the two standards; instead, each has 
been considered independently and we have applied the relevant factors 
to inform our negligible impact and small numbers determinations.
    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 
SAE's proposed 2013 open-water 3D OBC seismic survey in the Beaufort 
Sea, and none are proposed to be authorized. Additionally, animals in 
the area are not expected to incur hearing impairment (i.e., TTS or 
PTS) or non-auditory physiological effects. 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 marine 
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.
    Most of the bowhead whales encountered will likely show overt 
disturbance (avoidance) only if they receive airgun sounds with levels 
>= 160 dB re 1 [mu]Pa. Odontocete reactions to seismic airgun 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 the Beaufort Sea during the survey period

[[Page 35869]]

and few will likely be affected by the survey activity.
    As noted, elevated background noise level from the seismic airgun 
reverberant field could cause acoustic masking to marine mammals and 
reduce their communication space. However, even though the decay of the 
signal is extended, the fact that pulses are separated by approximately 
8 to 10 seconds (or 4 to 5 seconds by two separate source vessels 
stationed 300 to 335 m (990 to 1,100 ft) apart) means that overall 
received levels at distance are expected to be much lower, thus 
resulting in less acoustic masking.
    Taking into account the mitigation measures that are planned, 
effects on marine mammals are generally expected to be restricted to 
avoidance of a limited area around SAE's proposed open-water activities 
and short-term changes in behavior, falling within the MMPA definition 
of ``Level B harassment''. 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.
    Of the nine marine mammal species likely to occur in the proposed 
marine survey area, bowhead and humpback whales and ringed and bearded 
seals are listed as endangered or threatened under the ESA. These 
species are also designated as ``depleted'' under the MMPA. Despite 
these designations, the BCB stock of bowheads has been increasing at a 
rate of 3.4 percent annually for nearly a decade (Allen and Angliss 
2010). Additionally, during the 2001 census, 121 calves were counted, 
which was the highest yet recorded. The calf count provides 
corroborating evidence for a healthy and increasing population (Allen 
and Angliss 2010). The occurrence of fin and humpback whales in the 
proposed marine survey areas is considered very rare. There is no 
critical habitat designated in the U.S. Arctic for the bowhead and 
humpback whales. The Alaska stock of bearded seals, part of the 
Beringia distinct population segment (DPS), and the Arctic stock of 
ringed seals, have recently been listed by NMFS as threatened under the 
ESA. 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 vast size of the Arctic Ocean 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 estimated takes proposed to be authorized represent 0.09% of 
the Beaufort Sea population of approximately 39,258 beluga whales, 
0.01% of the Eastern North Pacific stock of approximately 19,126 gray 
whales, 1.19% of the Bering-Chukchi-Beaufort population of 10,545 
bowhead whales, 0.21% of the Western North Pacific stock of 
approximately 938 humpback whales, and 0.004% of the Baffin Bay stock 
of approximately 45,000 narwhals. The take estimates presented for 
ringed, bearded, spotted, and ribbon seals represent 1.71, 0.07, 0.30, 
and 0.004% of U.S. Arctic stocks of each species, respectively. 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.
    In addition, no important feeding and reproductive areas are known 
in the vicinity of SAE's proposed seismic surveys at the time the 
proposed surveys are to take place. No critical habitat of ESA-listed 
marine mammal species occurs in the Beaufort Sea.
    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 SAE's proposed 2013 open-water 
3D OBC seismic surveys in the Beaufort Sea 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.
Unmitigable Adverse Impact Analysis and Preliminary Determination
    NMFS has preliminarily determined that SAE's proposed 2013 open-
water 3D OBC seismic surveys in the Beaufort Sea will not have an 
unmitigable adverse impact on the availability of species or stocks for 
taking for subsistence uses. This preliminary determination is 
supported by information contained in this document and SAE's POC. SAE 
has adopted a spatial and temporal strategy for its Beaufort Sea open-
water seismic surveys that should minimize impacts to subsistence 
hunters. Due to the timing of the project and the distance from the 
surrounding communities, it is anticipated to have no effects on spring 
harvesting and little or no effects on the occasional summer harvest of 
beluga whale, subsistence winter seal hunts, or the fall bowhead hunt.
    In addition, based on the measures described in SAE's POC, the 
proposed mitigation and monitoring measures (described earlier in this 
document), and the project design itself, NMFS has determined 
preliminarily that there will not be an unmitigable adverse impact on 
subsistence uses from SAE's 2013 open-water 3D OBC seismic surveys in 
the Beaufort Sea.

Proposed Incidental Harassment Authorization

    This section contains a draft of the IHA itself. The wording 
contained in this section is proposed for inclusion in the IHA (if 
issued).
    (1) This Authorization is valid from July 15, 2013, through October 
31, 2013.
    (2) This Authorization is valid only for activities associated with 
open-water 3D seismic surveys and related activities in the Beaufort 
Sea. The specific areas where SAE's surveys will be conducted are 
within the Beaufort Sea, Alaska, as shown in Figure 1-1 of SAE's IHA 
application.
    (3)(a) The species authorized for incidental harassment takings, 
Level B harassment only, are: Beluga whales (Delphinapterus leucas); 
narwhals (Monodon monoceros); bowhead whales (Balaena mysticetus); gray 
whales (Eschrichtius robustus); humpback whales (Megaptera 
novaeangliae); bearded seals (Erignathus barbatus); spotted seals 
(Phoca largha); ringed seals (P. hispida); and ribbon seals (P. 
fasciata).
    (3)(b) The authorization for taking by harassment is limited to the 
following acoustic sources and from the following activities:
    (i) 440-in\3\, 880-in\3\, and 1,760-in\3\ airgun arrays and other 
acoustic sources for 3D open-water seismic surveys; and

[[Page 35870]]

    (ii) Vessel activities related to open-water seismic surveys listed 
in (i).
    (3)(c) The taking of any marine mammal in a manner prohibited under 
this Authorization must be reported within 24 hours of the taking to 
the Alaska Regional Administrator (907-586-7221) or his designee in 
Anchorage (907-271-3023), National Marine Fisheries Service (NMFS) and 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, at (301) 427-8401, or his designee (301-427-8418).
    (4) The holder of this Authorization must notify the Chief of the 
Permits and Conservation Division, Office of Protected Resources, at 
least 48 hours prior to the start of collecting seismic data (unless 
constrained by the date of issuance of this Authorization in which case 
notification shall be made as soon as possible).
    (5) Prohibitions
    (a) The taking, by incidental harassment only, is limited to the 
species listed under condition 3(a) above and by the numbers listed in 
Table 3. The taking by Level A harassment, injury or death of these 
species or the taking by harassment, injury or death of any other 
species of marine mammal is prohibited and may result in the 
modification, suspension, or revocation of this Authorization.
    (b) The taking of any marine mammal is prohibited whenever the 
required source vessel protected species observers (PSOs), required by 
condition 7(a)(i), are not onboard in conformance with condition 
7(a)(i) of this Authorization.
    (6) Mitigation
    (a) Establishing Exclusion and Disturbance Zones
    (i) Establish and monitor with trained PSOs a preliminary exclusion 
zones for cetaceans surrounding the airgun array on the source vessel 
where the received level would be 180 dB (rms) re 1 [micro]Pa. For 
purposes of the field verification test, described in condition 
7(e)(i), these radii are estimated to be 325, 494, and 842 m from the 
seismic source for the 440-in\3\, 880-in\3\, and 1,760-in\3\ airgun 
arrays, respectively.
    (ii) Establish and monitor with trained PSOs a preliminary 
exclusion zones for pinnipeds surrounding the airgun array on the 
source vessel where the received level would be 190 dB (rms) re 1 
[micro]Pa. For purposes of the field verification test, described in 
condition 7(e)(i), these radii are estimated to be 126, 167, and 321 m 
from the seismic source for the 440-in\3\, 880-in\3\, and 1,760-in\3\ 
airgun arrays, respectively.
    (iii) Establish a zone of influence (ZOIs) for cetaceans and 
pinnipeds surrounding the airgun array on the source vessel where the 
received level would be 160 dB (rms) re 1 [micro]Pa. For purposes of 
the field verification test described in condition 7(e)(i), these radii 
are estimated to be 1,330, 1,500, and 2,990 m from the seismic source 
for the 440-in\3\, 880-in\3\, and 1,760-in\3\ airgun arrays, 
respectively.
    (iv) Immediately upon completion of data analysis of the field 
verification measurements required under condition 7(e)(i) below, the 
new 160-dB, 180-dB, and 190-dB marine mammal ZOIs and exclusion zones 
shall be established based on the sound source verification.
    (b) Vessel Movement Mitigation:
    (i) Avoid concentrations or groups of whales by all vessels under 
the direction of SAE. Operators of support vessels should, at all 
times, conduct their activities at the maximum distance possible from 
such concentrations of whales.
    (ii) Vessels in transit shall be operated at speeds necessary to 
ensure no physical contact with whales occurs. If any vessel approaches 
within 1.6 km (1 mi) of observed bowhead whales, except when providing 
emergency assistance to whalers or in other emergency situations, the 
vessel operator will take reasonable precautions to avoid potential 
interaction with the bowhead whales by taking one or more of the 
following actions, as appropriate:
    (A) Reducing vessel speed to less than 5 knots within 300 yards 
(900 feet or 274 m) of the whale(s);
    (B) Steering around the whale(s) if possible;
    (C) Operating the vessel(s) in such a way as to avoid separating 
members of a group of whales from other members of the group;
    (D) Operating the vessel(s) to avoid causing a whale to make 
multiple changes in direction; and
    (E) Checking the waters immediately adjacent to the vessel(s) to 
ensure that no whales will be injured when the propellers are engaged.
    (iii) When weather conditions require, such as when visibility 
drops, adjust vessel speed accordingly to avoid the likelihood of 
injury to whales.
    (c) Mitigation Measures for Airgun Operations
    (i) Ramp-up:
    (A) A ramp up, following a cold start, can be applied if the 
exclusion zone has been free of marine mammals for a consecutive 30-
minute period. The entire exclusion zone must have been visible during 
these 30 minutes. If the entire exclusion zone is not visible, then 
ramp up from a cold start cannot begin.
    (B) If a marine mammal(s) is sighted within the exclusion zone 
during the 30-minute watch prior to ramp up, ramp up will be delayed 
until the marine mammal(s) is sighted outside of the exclusion zone or 
the animal(s) is not sighted for at least 15-30 minutes: 15 minutes for 
pinnipeds, or 30 minutes for cetaceans.
    (C) If, for any reason, electrical power to the airgun array has 
been discontinued for a period of 10 minutes or more, ramp-up 
procedures shall be implemented. Only if the PSO watch has been 
suspended, a 30-minute clearance of the exclusion zone is required 
prior to commencing ramp-up. Discontinuation of airgun activity for 
less than 10 minutes does not require a ramp-up.
    (D) The seismic operator and PSOs shall maintain records of the 
times when ramp-ups start and when the airgun arrays reach full power.
    (ii) Power-down/Shutdown:
    (A) The airgun array shall be immediately powered down whenever a 
marine mammal is sighted approaching close to or within the applicable 
exclusion zone of the full array, but is outside the applicable 
exclusion zone of the single mitigation airgun.
    (B) If a marine mammal is already within the exclusion zone when 
first detected, the airguns shall be powered down immediately.
    (C) Following a power-down, firing of the full airgun array shall 
not resume until the marine mammal has cleared the exclusion. The 
animal will be considered to have cleared the exclusion zone if it is 
visually observed to have left the exclusion zone of the full array, or 
has not been seen within the zone for 15 minutes (pinnipeds) or 30 
minutes (cetaceans).
    (D) If a marine mammal is sighted within or about to enter the 190 
or 180 dB (rms) applicable exclusion zone of the single mitigation 
airgun, the airgun array shall be shutdown.
    (E) Firing of the full airgun array or the mitigation gun shall not 
resume until the marine mammal has cleared the exclusion zone of the 
full array or mitigation gun, respectively. The animal will be 
considered to have cleared the exclusion zone as described above under 
ramp up procedures.
    (iii) Poor Visibility Conditions:
    (A) If during foggy conditions, heavy snow or rain, or darkness, 
the full 180 dB exclusion zone is not visible, the airguns cannot 
commence a ramp-up procedure from a full shut-down.
    (B) If one or more airguns have been operational before nightfall 
or before the onset of poor visibility conditions, they can remain 
operational throughout the night or poor visibility conditions. In this 
case ramp-up procedures can be

[[Page 35871]]

initiated, even though the exclusion zone may not be visible, on the 
assumption that marine mammals will be alerted by the sounds from the 
single airgun and have moved away.
    (iv) Use of a Small-Volume Airgun during Turns and Transits
    (A) Throughout the seismic survey, particularly during turning 
movements, and short transits, SAE will employ the use of the smallest 
volume airgun (i.e., ``mitigation airgun'') to deter marine mammals 
from being within the immediate area of the seismic operations. The 
mitigation airgun would be operated at approximately one shot per 
minute and would not be operated for longer than three hours in 
duration (turns may last two to three hours for the proposed project).
    (B) During turns or brief transits (e.g., less than three hours) 
between seismic tracklines, one mitigation airgun will continue 
operating. The ramp-up procedure will still be followed when increasing 
the source levels from one airgun to the full airgun array. However, 
keeping one airgun firing will avoid the prohibition of a ``cold 
start'' during darkness or other periods of poor visibility. Through 
the use of this approach, seismic surveys using the full array may 
resume without the 30 minute observation period of the full exclusion 
zone required for a ``cold start''. PSOs will be on duty whenever the 
airguns are firing during daylight, during the 30 minute periods prior 
to ramp-ups.
    (d) Mitigation Measures for Subsistence Activities:
    (i) For the purposes of reducing or eliminating conflicts between 
subsistence whaling activities and SAE's survey program, the holder of 
this Authorization will participate with other operators in the 
Communication and Call Centers (Com-Center) Program. The Com-Centers 
will be operated 24 hours/day during the 2013 fall subsistence bowhead 
whale hunt.
    (ii) The appropriate Com-Center shall be notified if there is any 
significant change in plans.
    (iii) Upon notification by a Com-Center operator of an at-sea 
emergency, the holder of this Authorization shall provide such 
assistance as necessary to prevent the loss of life, if conditions 
allow the holder of this Authorization to safely do so.
    (7) Monitoring:
    (a) Vessel-based Visual Monitoring:
    (i) Vessel-based visual monitoring for marine mammals shall be 
conducted by NMFS-approved protected species observers (PSOs) 
throughout the period of survey activities.
    (ii) PSOs shall be stationed aboard the seismic survey vessels and 
mitigation vessel through the duration of the surveys.
    (iii) A sufficient number of PSOs shall be onboard the survey 
vessel to meet the following criteria:
    (A) 100% monitoring coverage during all periods of survey 
operations in daylight;
    (B) maximum of 4 consecutive hours on watch per PSO; and
    (C) maximum of 12 hours of watch time per day per PSO.
    (iv) The vessel-based marine mammal monitoring shall provide the 
basis for real-time mitigation measures as described in (6)(c) above.
    (v) Results of the vessel-based marine mammal monitoring shall be 
used to calculate the estimation of the number of ``takes'' from the 
marine surveys and equipment recovery and maintenance program.
    (b) Protected Species Observers and Training
    (i) PSO teams shall consist of Inupiat observers and NMFS-approved 
field biologists.
    (ii) Experienced field crew leaders shall supervise the PSO teams 
in the field. New PSOs shall be paired with experienced observers to 
avoid situations where lack of experience impairs the quality of 
observations.
    (iii) Crew leaders and most other biologists serving as observers 
in 2013 shall be individuals with experience as observers during recent 
seismic or shallow hazards monitoring projects in Alaska, the Canadian 
Beaufort, or other offshore areas in recent years.
    (iv) Resumes for PSO candidates shall be provided to NMFS for 
review and acceptance of their qualifications. Inupiat observers shall 
be experienced in the region and familiar with the marine mammals of 
the area.
    (v) All observers shall complete a NMFS-approved observer training 
course designed to familiarize individuals with monitoring and data 
collection procedures. The training course shall be completed before 
the anticipated start of the 2013 open-water season. The training 
session(s) shall be conducted by qualified marine mammalogists with 
extensive crew-leader experience during previous vessel-based 
monitoring programs.
    (vi) Training for both Alaska native PSOs and biologist PSOs shall 
be conducted at the same time in the same room. There shall not be 
separate training courses for the different PSOs.
    (vii) Crew members should not be used as primary PSOs because they 
have other duties and generally do not have the same level of 
expertise, experience, or training as PSOs, but they could be stationed 
on the fantail of the vessel to observe the near field, especially the 
area around the airgun array and implement a power down or shutdown if 
a marine mammal enters the safety zone (or exclusion zone).
    (viii) If crew members are to be used as PSOs, they shall go 
through some basic training consistent with the functions they will be 
asked to perform. The best approach would be for crew members and PSOs 
to go through the same training together.
    (ix) PSOs shall be trained using visual aids (e.g., videos, 
photos), to help them identify the species that they are likely to 
encounter in the conditions under which the animals will likely be 
seen.
    (x) SAE shall train its PSOs to follow a scanning schedule that 
consistently distributes scanning effort according to the purpose and 
need for observations. All PSOs should follow the same schedule to 
ensure consistency in their scanning efforts.
    (xi) PSOs shall be trained in documenting the behaviors of marine 
mammals. PSOs should simply record the primary behavioral state (i.e., 
traveling, socializing, feeding, resting, approaching or moving away 
from vessels) and relative location of the observed marine mammals.
    (c) Marine Mammal Observation Protocol
    (i) PSOs shall watch for marine mammals from the best available 
vantage point on the survey vessels, typically the bridge.
    (ii) Observations by the PSOs on marine mammal presence and 
activity shall begin a minimum of 30 minutes prior to the estimated 
time that the seismic source is to be turned on and/or ramped-up.
    (iii) PSOs shall scan systematically with the unaided eye and 7 x 
50 reticle binoculars, supplemented with 20 x 60 image-stabilized 
binoculars or 25 x 150 binoculars, and night-vision equipment when 
needed.
    (iv) Personnel on the bridge shall assist the marine mammal 
observer(s) in watching for marine mammals.
    (v) PSOs aboard the marine survey vessel shall give particular 
attention to the areas within the marine mammal exclusion zones around 
the source vessel, as noted in (6)(a)(i) and (ii). They shall avoid the 
tendency to spend too much time evaluating animal behavior or entering 
data on forms, both of which detract from their primary purpose of 
monitoring the exclusion zone.
    (vi) Monitoring shall consist of recording of the following 
information:
    (A) the species, group size, age/size/sex categories (if 
determinable), the

[[Page 35872]]

general behavioral activity, heading (if consistent), bearing and 
distance from seismic vessel, sighting cue, behavioral pace, and 
apparent reaction of all marine mammals seen near the seismic vessel 
and/or its airgun array (e.g., none, avoidance, approach, paralleling, 
etc);
    (B) the time, location, heading, speed, and activity of the vessel 
(shooting or not), along with sea state, visibility, cloud cover and 
sun glare at (I) any time a marine mammal is sighted (including 
pinnipeds hauled out on barrier islands), (II) at the start and end of 
each watch, and (III) during a watch (whenever there is a change in one 
or more variable);
    (C) the identification of all vessels that are visible within 5 km 
of the seismic vessel whenever a marine mammal is sighted and the time 
observed;
    (D) any identifiable marine mammal behavioral response (sighting 
data should be collected in a manner that will not detract from the 
PSO's ability to detect marine mammals);
    (E) any adjustments made to operating procedures; and
    (F) visibility during observation periods so that total estimates 
of take can be corrected accordingly.
    (vii) Distances to nearby marine mammals will be estimated with 
binoculars (7 x 50 binoculars) containing a reticle to measure the 
vertical angle of the line of sight to the animal relative to the 
horizon. Observers may use a laser rangefinder to test and improve 
their abilities for visually estimating distances to objects in the 
water.
    (viii) PSOs shall understand the importance of classifying marine 
mammals as ``unknown'' or ``unidentified'' if they cannot identify the 
animals to species with confidence. In those cases, they shall note any 
information that might aid in the identification of the marine mammal 
sighted. For example, for an unidentified mysticete whale, the 
observers should record whether the animal had a dorsal fin.
    (ix) Additional details about unidentified marine mammal sightings, 
such as ``blow only'', mysticete with (or without) a dorsal fin, ``seal 
splash'', etc., shall be recorded.
    (x) When a marine mammal is seen approaching or within the 
exclusion zone applicable to that species, the marine survey crew shall 
be notified immediately so that mitigation measures described in (6) 
can be promptly implemented.
    (xi) SAE shall use the best available technology to improve 
detection capability during periods of fog and other types of inclement 
weather. Such technology might include night-vision goggles or 
binoculars as well as other instruments that incorporate infrared 
technology.
    (d) Field Data-Recording and Verification
    (A) PSOs aboard the vessels shall maintain a digital log of seismic 
surveys, noting the date and time of all changes in seismic activity 
(ramp-up, power-down, changes in the active seismic source, shutdowns, 
etc.) and any corresponding changes in monitoring radii in a software 
spreadsheet.
    (B) PSOs shall utilize standardized format to record all marine 
mammal observations and mitigation actions (seismic source power-downs, 
shut-downs, and ramp-ups).
    (C) Information collected during marine mammal observations shall 
include the following:

(I) Vessel speed, position, and activity
(II) Date, time, and location of each marine mammal sighting
(III) Number of marine mammals observed, and group size, sex, and age 
categories
(IV) Observer's name and contact information
(V) Weather, visibility, and ice conditions at the time of observation
(VI) Estimated distance of marine mammals at closest approach
(VII) Activity at the time of observation, including possible 
attractants present
(VIII) Animal behavior
(IX) Description of the encounter
(X) Duration of encounter
(XI) Mitigation action taken

    (D) Data shall be recorded directly into handheld computers or as a 
back-up, transferred from hard-copy data sheets into an electronic 
database.
    (E) A system for quality control and verification of data shall be 
facilitated by the pre-season training, supervision by the lead PSOs, 
in-season data checks, and shall be built into the software.
    (F) Computerized data validity checks shall also be conducted, and 
the data shall be managed in such a way that it is easily summarized 
during and after the field program and transferred into statistical, 
graphical, or other programs for further processing.
    (e) Passive Acoustic Monitoring
    (i) Sound Source Measurements: Using a hydrophone system, the 
holder of this Authorization is required to conduct sound source 
verification tests for seismic airgun array(s) and other marine survey 
equipment that are involved in the open-water seismic surveys.
    (A) Sound source verification shall consist of distances where 
broadside and endfire directions at which broadband received levels 
reach 190, 180, 170, and 160 dB (rms) re 1 [mu]Pa for the airgun 
array(s). The configurations of airgun arrays shall include at least 
the full array and the operation of a single source that will be used 
during power downs.
    (B) The test results shall be reported to NMFS within 5 days of 
completing the test.
    (ii) Passive Acoustic Monitoring (PAM)
    (A) SAE shall conduct passive acoustic monitoring using fixed 
hydrophone(s) to (I) collect information on the occurrence and 
distribution of marine mammals (including beluga whale, bowhead whale, 
walrus and other species) that may be available to subsistence hunters 
near villages located on the Beaufort Sea coast and to document their 
relative abundance, habitat use, and migratory patterns; and (II) 
measure the ambient soundscape throughout the Beaufort Sea coast and to 
record received levels of sounds from industry and other activities.
    (f) Pinniped Surveys Before, During and After Seismic Surveys
    (i) SAE shall conduct a pinniped survey in the proposed seismic 
survey area before, during, and after the seismic surveys to provide a 
basis for determining whether ringed and bearded seals alter their 
habitat use patterns during the seismic survey.
    (ii) The design of the pinniped survey will focus on resident 
ringed and spotted seals, spotted seal haul out use in the Colville 
River delta.
    (g) SAE shall engage in consultation and coordination with other 
oil and gas companies and with federal, state, and borough agencies to 
ensure that they have the most up-to-date information and can take 
advantage of other monitoring efforts; and
    (8) Data Analysis and Presentation in Reports:
    (a) Estimation of potential takes or exposures shall be improved 
for times with low visibility (such as during fog or darkness) through 
interpolation or possibly using a probability approach. Those data 
could be used to interpolate possible takes during periods of 
restricted visibility.
    (b) SAE shall provide a database of the information collected, plus 
a number of summary analyses and graphics to help NMFS assess the 
potential impacts of their survey. Specific summaries/analyses/graphics 
would include:
    (i) sound verification results including isopleths of sound 
pressure levels plotted geographically;

[[Page 35873]]

    (ii) a table or other summary of survey activities (i.e., did the 
survey proceed as planned);
    (iii) a table of sightings by time, location, species, and distance 
from the survey vessel;
    (iv) a geographic depiction of sightings for each species by area 
and month;
    (v) a table and/or graphic summarizing behaviors observed by 
species;
    (vi) a table and/or graphic summarizing observed responses to the 
survey by species;
    (vii) a table of mitigation measures (e.g., powerdowns, shutdowns) 
taken by date, location, and species;
    (viii) a graphic of sightings by distance for each species and 
location;
    (ix) a table or graphic illustrating sightings during the survey 
versus sightings when the airguns were silent; and
    (x) a summary of times when the survey was interrupted because of 
interactions with marine mammals.
    (c) To help evaluate the effectiveness of PSOs and more effectively 
estimate take, if appropriate data are available, SAE shall perform 
analysis of sightability curves (detection functions) for distance-
based analyses.
    (d) SAE shall collaborate with other organizations operating in the 
Beaufort Sea and share visual and acoustic data to improve 
understanding of impacts from single and multiple operations and 
efficacy of mitigation measures.
    (9) Reporting:
    (a) Sound Source Verification Report: A report on the preliminary 
results of the sound source verification measurements, including the 
measured 190, 180, and 160 dB (rms) radii of the airgun sources and 
other acoustic survey equipment, shall be submitted within 14 days 
after collection of those measurements at the start of the field 
season. This report will specify the distances of the exclusion zones 
that were adopted for the survey.
    (b) Throughout the survey program, PSOs shall prepare a report each 
day or at such other intervals, summarizing the recent results of the 
monitoring program. The reports shall summarize the species and numbers 
of marine mammals sighted. These reports shall be provided to NMFS.
    (c) Seismic Vessel Monitoring Program: A draft report will be 
submitted to the Director, Office of Protected Resources, NMFS, within 
90 days after the end of SAE's 2013 open-water seismic surveys in the 
Beaufort Sea. The report will describe in detail:
    (i) 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);
    (ii) analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    (iii) 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;
    (iv) to better assess impacts to marine mammals, data analysis 
should be separated into periods when an airgun array (or a single 
airgun) is operating and when it is not. Final and comprehensive 
reports to NMFS should summarize and plot: (A) Data for periods when a 
seismic array is active and when it is not; and (B) The respective 
predicted received sound conditions over fairly large areas (tens of 
km) around operations.
    (v) sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability), such as: (A) initial sighting distances versus airgun 
activity state; (B) closest point of approach versus airgun activity 
state; (C) observed behaviors and types of movements versus airgun 
activity state; (D) numbers of sightings/individuals seen versus airgun 
activity state; (E) distribution around the survey vessel versus airgun 
activity state; and (F) estimates of take by harassment.
    (vi) reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable.
    (vii) estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available.
    (viii) The report should clearly compare authorized takes to the 
level of actual estimated takes.
    (d) The draft report shall be subject to review and comment by 
NMFS. Any recommendations made by NMFS must be addressed in the final 
report prior to acceptance by NMFS. The draft report will be considered 
the final report for this activity under this Authorization if NMFS has 
not provided comments and recommendations within 90 days of receipt of 
the draft report.
    (10) (a) In the unanticipated event that survey operations clearly 
cause the take of a marine mammal in a manner prohibited by this 
Authorization, such as an injury (Level A harassment), serious injury 
or mortality (e.g., ship-strike, gear interaction, and/or 
entanglement), SAE shall immediately cease survey operations and 
immediately report the incident to the Supervisor of the Incidental 
Take Program, Permits and Conservation Division, Office of Protected 
Resources, NMFS, at 301-427-8401 and/or by email to 
Jolie.Harrison@noaa.gov and Shane.Guan@noaa.gov and the Alaska Regional 
Stranding Coordinators (Aleria.Jensen@noaa.gov and 
Barbara.Mahoney@noaa.gov). The report must include the following 
information:
    (i) time, date, and location (latitude/longitude) of the incident;
    (ii) the name and type of vessel involved;
    (iii) the vessel's speed during and leading up to the incident;
    (iv) description of the incident;
    (v) status of all sound source use in the 24 hours preceding the 
incident;
    (vi) water depth;
    (vii) environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (viii) description of marine mammal observations in the 24 hours 
preceding the incident;
    (ix) species identification or description of the animal(s) 
involved;
    (x) the fate of the animal(s); and
    (xi) photographs or video footage of the animal (if equipment is 
available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with SAE to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. SAE may not resume their 
activities until notified by NMFS via letter, email, or telephone.
    (b) In the event that SAE discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
SAE will immediately report the incident to the Supervisor of the 
Incidental Take Program, Permits and Conservation Division, Office of 
Protected Resources, NMFS, at 301-427-8401, and/or by email to 
Jolie.Harrison@noaa.gov and Shane.Guan@noaa.gov and the NMFS Alaska 
Stranding Hotline (1-877-925-7773) and/or by email to the Alaska 
Regional Stranding Coordinators (Aleria.Jensen@noaa.gov and 
Barabara.Mahoney@noaa.gov). The report must include the same

[[Page 35874]]

information identified in Condition 10(a) above. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
will work with SAE to determine whether modifications in the activities 
are appropriate.
    (c) In the event that SAE discovers an injured or dead marine 
mammal, and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in Condition 3 
of this Authorization (e.g., previously wounded animal, carcass with 
moderate to advanced decomposition, or scavenger damage), SAE shall 
report the incident to the Supervisor of the Incidental Take Program, 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
at 301-427-8401, and/or by email to Jolie.Harrison@noaa.gov and 
Shane.Guan@noaa.gov and the NMFS Alaska Stranding Hotline (1-877-925-
7773) and/or by email to the Alaska Regional Stranding Coordinators 
(Aleria.Jensen@noaa.gov and Barbara.Mahoney@noaa.gov), within 24 hours 
of the discovery. SAE shall provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network. SAE can continue its 
operations under such a case.
    (11) Activities related to the monitoring described in this 
Authorization do not require a separate scientific research permit 
issued under section 104 of the Marine Mammal Protection Act.
    (12) The Plan of Cooperation outlining the steps that will be taken 
to cooperate and communicate with the native communities to ensure the 
availability of marine mammals for subsistence uses, must be 
implemented.
    (13) This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein or if the 
authorized taking is having more than a negligible impact on the 
species or stock of affected marine mammals, or if there is an 
unmitigable adverse impact on the availability of such species or 
stocks for subsistence uses.
    (14) A copy of this Authorization and the Incidental Take Statement 
must be in the possession of each seismic vessel operator taking marine 
mammals under the authority of this Incidental Harassment 
Authorization.
    (15) SAE is required to comply with the Terms and Conditions of the 
Incidental Take Statement corresponding to NMFS' Biological Opinion.

Endangered Species Act (ESA)

    The bowhead and humpback whales and ringed and bearded seals are 
the only marine mammal species currently listed as endangered or 
threatened under the ESA that could occur during SAE's proposed seismic 
surveys during the Arctic open-water season. NMFS' Permits and 
Conservation Division has initiated consultation with NMFS' Protected 
Resources Division under section 7 of the ESA on the issuance of an IHA 
to SAE 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 SAE's 2013 open-
water 3D OBC seismic surveys in the Alaskan Beaufort Sea, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: June 10, 2013.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2013-14188 Filed 6-11-13; 4:15 pm]
BILLING CODE 3510-22-P