Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Shallow Hazards Survey in the Chukchi Sea, Alaska, 30110-30130 [2011-12666]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 76, Number 100 (Tuesday, May 24, 2011)]
[Notices]
[Pages 30110-30130]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-12666]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XA396


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Shallow Hazards Survey in the 
Chukchi 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 Statoil USA E&P Inc. 
(Statoil) for an Incidental Harassment Authorization (IHA) to take 
marine mammals, by harassment, incidental to a proposed open water 
shallow hazards survey in the Chukchi Sea, Alaska, between July through 
November 2011. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an IHA to Statoil 
to take, by Level B harassment only, thirteen species of marine mammals 
during the specified activity.

DATES: Comments and information must be received no later than June 23, 
2011.

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

[[Page 30111]]

FURTHER INFORMATION CONTACT), or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited in this 
notice may also be viewed, by appointment, during regular business 
hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected 
Resources, NMFS, (301) 713-2289, ext 137.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``* * * an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as:

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

Summary of Request

    NMFS received an application on March 1, 2011, from Statoil for the 
taking, by harassment, of marine mammals incidental to shallow hazards 
site surveys and soil investigations (geotechnical boreholes) in the 
Chukchi Sea, Alaska, during the 2011 open-water season. After 
addressing comments from NMFS, Statoil modified its application and 
submitted a revised application on April 19, 2011. The April 19, 2011, 
application is the one available for public comment (see ADDRESSES) and 
considered by NMFS for this proposed IHA.
    The proposed shallow hazards and site clearance surveys would use a 
towed airgun cluster consisting of four, 10-in\3\ airguns with a ~600 m 
towed hydrophone streamer, as well as additional lower-powered and 
higher frequency survey equipment for collecting bathymetric and 
shallow sub-bottom data. The proposed survey will take place on and 
near Statoil's leases in the Chukchi Sea, covering a total area of ~665 
km\2\ located ~240 km (150 mi) west of Barrow and ~165 km (103 mi) 
northwest of Wainwright, in water depths of ~30-50 m (100-165 ft).
    The proposed geotechnical soil investigations will take place at 
prospective drilling locations on Statoil's leases and leases jointly 
owned with ConocoPhillips Alaska Inc. (CPAI). All cores will be either 
2.1 in. or 2.8 in. in diameter (depending on soil type) and those 
collected at prospective drilling locations will be up to 100 m in 
depth. The maximum total number of samples collected as part of the 
drilling location and site survey program will be ~29.
    Statoil intends to conduct these marine surveys during the 2011 
Arctic open-water season (July through November). Impacts to marine 
mammals may occur from noise produced from active acoustic sources 
(including airguns) used in the surveys.

Description of the Specified Activity

    Statoil acquired 16 leases in the Chukchi Sea during Lease Sale 193 
held in February 2008. The leased areas are located ~240 km (150 mi) 
west of Barrow and ~160 km (~100 mi) northwest of Wainwright. During 
the open-water season of 2010, Statoil conducted a 3D seismic survey 
over its lease holdings and the surrounding area. The data gathered 
during that survey are currently being analyzed in order to determine 
potential well locations on the leases. These analyses will be 
completed prior to commencement of the site survey program. During the 
open-water season of 2011, Statoil proposes to conduct shallow hazards 
and site clearance surveys (site surveys) and soil investigations 
(geotechnical boreholes).
    The proposed operations will be performed from two different 
vessels. Shallow hazards surveys will be conducted from the M/V Duke, 
while geotechnical soil investigations will be conducted from the M/V 
Fugro Synergy (see Statoil's application for vessel specifications). 
Both vessels will mobilize from Dutch Harbor in late July and arrive in 
the Chukchi Sea to begin work on or after 1 August. Allowing for poor 
weather days, operations are expected to continue into late September 
or early October. However, if weather permits and all planned 
activities have not been completed, operations may continue as late as 
15 November.
    The site survey work on Statoil's leases will require approximately 
23 days to complete. Geotechnical soil investigations on Statoil leases 
and on leases jointly held with CPAI will require ~14 days of 
operations.

Shallow Hazards and Site Clearance Surveys

    Shallow hazards site surveys are designed to collect bathymetric 
and shallow sub-seafloor data that allow the evaluation of potential 
shallow faults, gas zones, and archeological features at prospective 
exploration drilling locations, as required by the Bureau of Ocean 
Energy Management, Regulation, and Enforcement (BOEMRE). Data are 
typically collected using multiple types of acoustic equipment. During 
the site surveys, Statoil proposes to use the following acoustic 
sources: 4x10 in\3\ airgun cluster, single 10 in\3\ airgun, Kongsberg 
SBP3000 sub-bottom profiler, GeoAcoustics 160D side-scan sonar, and a 
Kongsberg EM2040 multi-beam echosounder. The operating frequencies and 
estimated source levels of this equipment are provided below.
1. Airguns
    A 4x10 in\3\ airgun cluster will be used to obtain geological data 
during the shallow hazards survey. A similar airgun cluster was 
measured by Shell in 2009 during shallow hazards surveys on their 
nearby Burger prospect (Reiser et al. 2010). The measurements resulted 
in 90th percentile propagation loss equations of RL =

[[Page 30112]]

218.0-17.5LogR-0.00061R for a 4x10 in\3\ airgun cluster and RL = 204.4-
16.0LogR-0.00082R for a single 10 in\3\ airgun (where RL = received 
level and R = range). The estimated 190, 180, and 160 dBrms 
re 1 [mu]Pa isopleths are estimated at 39 m, 150 m, and 1,800 m from 
the source. More accurate isopleths at these received levels will be 
established prior to Statoil's shallow hazards survey (see below).
2. Kongsberg SBP300 Sub-Bottom Profiler
    This instrument will be operated from the M/V Duke during site 
survey operations. This sub-bottom profiler operates at frequencies 
between 2 and 7 kHz with a manufacturer specified source level of ~225 
dB re 1 [mu]Pa-m. The sound energy is projected downwards from the hull 
in a maximum 15[deg] cone. However, field measurements of similar 
instruments in previous years have resulted in much lower actual source 
levels (range 161-186 dB) than specified by the manufacturers (i.e. the 
manufacturer source level of one instrument was reported as 214 dB, and 
field measurements resulted in a source level estimate of 186.2 dB) 
(Reiser et al. 2010). Although it is not known whether these field 
measurements captured the narrow primary beam produced by the 
instruments, Statoil will measure the sounds produced by this 
instrument (and all other survey equipment) at the start of operations 
and if sounds from the instrument are found to be above mitigation 
threshold levels (180 dB for cetaceans, 190 dB for seals) at a distance 
beyond the footprint of the vessel, then the same power-down and shut-
down mitigation measures used during airgun operations will be employed 
during use of the sub-bottom profiler.
3. GeoAcoustics 160D Side-Scan Sonar
    The side-scan sonar will be operated from the M/V Duke during site 
survey operations. This unit operates at 114 kHz and 410 kHz with a 
source level of ~233 dB re 1 [mu]Pa-m. The sound energy is emitted in a 
fan shaped pattern that is narrow (0.3-1.0[deg]) in the fore/aft 
direction of the vessel and broad (40-50[deg]) in the port/starboard 
direction.
4. Kongsberg EM2040 Multi-Beam Echosounder
    Multi-beam echosounders also emit energy in a fan-shaped pattern, 
similar to the side-scan sonar described above. This unit operates at 
200 to 400 kHz with a source level of ~210 dB re 1 [mu]Pa-m. The beam 
width is 1.5[deg] in the fore/aft direction. The multi-beam echosounder 
will be operated from the M/V Duke during site surveys operations.

Geotechnical Soil Investigations

    Geotechnical soil investigations are performed to collect detailed 
data on seafloor sediments and geological structure to a maximum depth 
of 100 m. These data are then evaluated to help determine the 
suitability of the site as a drilling location. Statoil has contracted 
with Fugro who will use the vessel M/V Fugro Synergy to complete the 
planned soil investigations. Three to four bore holes will be collected 
at each of up to 5 prospective drilling locations on Statoil's leases 
and up to 3 boreholes may be completed at each of up to 3 potential 
drilling locations on leases jointly owned with CPAI. This would result 
in a maximum total of 29 bore holes to be completed as part of the 
geotechnical soil investigation program. The Fugro Synergy operates a 
Kongsberg EA600 Echosounder and uses a Kongsberg 500 high precision 
acoustic positioning (HiPAP) system for precise vessel positioning 
while completing the boreholes. The operating frequencies and estimated 
source levels of the acoustic equipment, as well as the sounds produced 
during soil investigation sampling, are provided in the sub-section 
below.
1. Kongsberg EA600 Echosounder
    This echosounder will be operated from the M/V Fugro Synergy 
routinely as a fathometer to provide depth information to the bridge 
crew. This model is capable of simultaneously using 4 transducers, each 
with a separate frequency. However, only 2 transducers will be mounted 
and used during this project. These transducers will operate at 18 kHz 
and 200 kHz and have similar or slightly lower source levels than the 
multi-beam echosounder described above. The energy from these 
transducers is emitted in a conical beam from the hull of the vessel 
downward to the seafloor.
2. Kongsberg HiPAP 500
    The Kongsberg high precision acoustic positioning system (HiPAP) 
500 is used to aid the positioning of the M/V Fugro Synergy during soil 
investigation operations. An acoustic signal is sent and received by a 
transponder on the hull of the vessel and a transponder lowered to the 
seafloor near the borehole location. The two transponders communicated 
via signals with a frequency of between 21-30.5 kHz with source levels 
expected to be in the 200-210 dB range.
3. Geotechnical Soil Investigation Sounds
    In-water sounds produced during soil investigation operations by 
the M/V Fugro Synergy have not previously been measured and estimates 
of such activities vary. Measurements of another Fugro vessel that 
often conducts soil investigations were made in the Gulf of Mexico in 
2009. However, because measurements were taken using a towed hydrophone 
system, recordings of soil investigation related sounds could not be 
made while the vessel was stationary. Therefore, sounds recorded while 
the vessel was in transit were compared to sounds recorded while the 
vessel also operated generators and mechanical equipment associated 
with soil investigation operations while in transit. The difference in 
sound levels during transit alone and during transit with soil 
investigation equipment operating was negligible and this was 
attributed to the fact that transit noise was dominant up to at least 7 
kHz and likely masked the lower frequency sounds produced by the 
simulated soil investigation activities.
4. Dynamic Positioning Sound
    During soil investigation operations, the M/V Fugro Synergy will 
remain stationary relative to the seafloor by means of a dynamic 
positioning (DP) system that automatically controls and coordinates 
vessel movements using bow and/or stern thrusters as well as the 
primary propeller(s). The sounds produced by soil investigation 
equipment are not likely to substantially increase overall source 
levels beyond those produced by the various thrusters while in DP mode. 
Measurements of a vessel in DP mode with an active bow thruster were 
made in the Chukchi Sea in 2010 (Chorney et al. 2011). The resulting 
source level estimate was 175.9 dBrms re 1 [mu]Pa-m. Using 
the transmission loss equation from measurements of a single 60 in\3\ 
airgun on Statoil's lease in 2010 (RL = 205.6-13.9LogR-0.00093R; 
O'Neill et al. 2011) and replacing the constant term with the 175.9 
results in an estimated range of 4.97 km to the 120 dB level. To allow 
for uncertainties and some additional sound energy being contributed by 
the operating soil investigation equipment, an inflation factor of 1.5 
was applied to arrive at an estimated >= 120 dB radius of 7.5 km for 
soil investigation activities.

Description of Marine Mammals in the Area of the Specified Activity

    Nine cetacean and four seal species could occur in the general area 
of the

[[Page 30113]]

site clearance and shallow hazards survey. The marine mammal species 
under NMFS's jurisdiction most likely to occur near operations in the 
Chukchi and Beaufort seas include four cetacean species: Beluga whale 
(Delphinapterus leucas), bowhead whale (Balaena mysticetus), gray whale 
(Eschrichtius robustus), and harbor porpoise (Phocoena phocoena), and 
three seal species: ringed (Phoca hispida), spotted (P. largha), and 
bearded seals (Erignathus barbatus). The marine mammal species that is 
likely to be encountered most widely (in space and time) throughout the 
period of the planned site clearance and shallow hazards surveys is the 
ringed seal.
    Other marine mammal species that have been observed in the Chukchi 
Sea but are less frequent or uncommon in the project area include 
narwhal (Monodon monoceros), killer whale (Orcinus orca), fin whale 
(Balaenoptera physalus), minke whale (B. acutorostrata), humpback whale 
(Megaptera novaeangliae), and ribbon seal (Histriophoca fasciata). 
These species could occur in the project area, but each of these 
species is uncommon or rare in the area and relatively few encounters 
with these species are expected during the proposed shallow hazards 
survey. The narwhal occurs in Canadian waters and occasionally in the 
Beaufort Sea, but it is rare there and is not expected to be 
encountered. There are scattered records of narwhal in Alaskan waters, 
including reports by subsistence hunters, where the species is 
considered extralimital (Reeves et al. 2002).
    The bowhead, fin, and humpback whales are listed as ``endangered'' 
under the Endangered Species Act (ESA) and as depleted under the MMPA. 
Certain stocks or populations of gray, beluga, and killer whales and 
spotted seals are listed as endangered or proposed for listing under 
the ESA; however, none of those stocks or populations occur in the 
proposed activity area. Additionally, the ribbon seal is considered a 
``species of concern'' under the ESA, and the bearded and ringed seals 
are ``candidate species'' under the ESA, meaning they are currently 
being considered for listing.
    Statoil's application contains information on the status, 
distribution, seasonal distribution, and abundance of each of the 
species under NMFS jurisdiction mentioned in this document. Please 
refer to the application for that information (see ADDRESSES). 
Additional information can also be found in the NMFS Stock Assessment 
Reports (SAR). The Alaska 2010 SAR is available at: https://www.nmfs.noaa.gov/pr/pdfs/sars/ak2010.pdf.

Potential Effects of the Specified Activity on Marine Mammals

    Operating active acoustic sources such as an airgun array has 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) Tolerance
    Numerous studies have shown that pulsed sounds from airguns are 
often readily detectable in the water at distances of many kilometers. 
Numerous studies have also shown that marine mammals at distances more 
than a few kilometers from operating survey vessels often show no 
apparent response. That is often true even in cases when the pulsed 
sounds must be readily audible to the animals based on measured 
received levels and the hearing sensitivity of that mammal group. 
Although various baleen whales, toothed whales, and (less frequently) 
pinnipeds have been shown to react behaviorally to airgun pulses under 
some conditions, at other times, mammals of all three types have shown 
no overt reactions. In general, pinnipeds and small odontocetes seem to 
be more tolerant of exposure to airgun pulses than baleen whales.
(2) Behavioral Disturbance
    Marine mammals may behaviorally react to sound when exposed to 
anthropogenic noise. These behavioral reactions are often shown as: 
changing durations of surfacing and dives, number of blows per 
surfacing, or moving direction and/or speed; reduced/increased vocal 
activities; changing/cessation of certain behavioral activities (such 
as socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where noise sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haulouts or rookeries).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, and reproduction. Some of these 
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 at received level for 
impulse noises (such as airgun pulses) as the onset of marine mammal 
behavioral harassment.
(3) Masking
    Chronic exposure to excessive, though not high-intensity, noise 
could cause masking at particular frequencies for marine mammals that 
utilize sound for vital biological functions. Masking can interfere 
with detection of acoustic signals such as communication calls, 
echolocation sounds, and environmental sounds important to marine 
mammals. Since marine mammals depend on acoustic cues for vital 
biological functions, such as orientation, communication, finding prey, 
and avoiding predators, marine mammals that experience severe acoustic 
masking will have reduced fitness in survival and reproduction.
    Masking occurs when noise and signals (that the animal utilizes) 
overlap at both spectral and temporal scales. For the airgun noise 
generated from the proposed site clearance and shallow hazards surveys, 
noise will consist of 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

[[Page 30114]]

sounds such as surf and prey noise. There is little concern regarding 
masking near the noise source due to the brief duration of these pulses 
and relatively longer silence between airgun shots (9-12 seconds). 
However, at long distances (over tens of kilometers away), due to 
multipath propagation and reverberation, the durations of airgun pulses 
can be ``stretched'' to seconds with long decays (Madsen et al. 2006). 
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. 2009) and cause 
increased stress levels (e.g., Foote et al. 2004; Holt et al. 2009). 
Nevertheless, the intensity of the noise is also greatly reduced at 
such long distances (for example, the modeled received level drops 
below 120 dB re 1 [mu]Pa rms at 14,900 m from the source).
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior such as shifting call frequencies, 
increasing call volume and vocalization rates. For example, blue whales 
are found to increase call rates when exposed to seismic survey noise 
in the St. Lawrence Estuary (Di Iorio and Clark 2010). The North 
Atlantic right whales (Eubalaena glacialis) exposed to high shipping 
noise increase call frequency (Parks et al. 2007), while some humpback 
whales respond to low-frequency active sonar playbacks by increasing 
song length (Miller el al. 2000).
(4) Hearing Impairment
    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift (TS), which is 
the loss of hearing sensitivity at certain frequency ranges (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be 
permanent (PTS), in which case the loss of hearing sensitivity is 
unrecoverable, or temporary (TTS), in which case the animal's hearing 
threshold will recover over time (Southall et al. 2007). Just like 
masking, marine mammals that suffer from PTS or TTS will have reduced 
fitness in survival and reproduction, either permanently or 
temporarily. Repeated noise exposure that leads to TTS could cause PTS. 
For transient sounds, the sound level necessary to cause TTS is 
inversely related to the duration of the sound.
    Experiments on a bottlenose dolphin (Tursiops 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. Although 
the source level of pile driving from one hammer strike is expected to 
be much lower than the single watergun impulse cited here, animals 
being exposed for a prolonged period to repeated hammer strikes could 
receive more noise exposure in terms of SEL than from the single 
watergun impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the 
aforementioned experiment (Finneran et al. 2002).
    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; 
Ketten et al. 2001). However, more recent indications are that TTS 
onset in the most sensitive pinniped species studied (harbor seal, 
which is closely related to the ringed seal) may occur at a similar SEL 
as in odontocetes (Kastak et al., 2004).
    NMFS (1995, 2000) concluded that cetaceans and pinnipeds should not 
be exposed to pulsed underwater noise at received levels exceeding, 
respectively, 180 and 190 dB re 1 [mu]Pa rms. The established 180- and 
190-dB re 1 [mu]Pa rms criteria are not considered to be the levels 
above which TTS might occur. Rather, they are the received levels above 
which, in the view of a panel of bioacoustics specialists convened by 
NMFS before TTS measurements for marine mammals started to become 
available, one could not be certain that there would be no injurious 
effects, auditory or otherwise, to marine mammals. As summarized above, 
data that are now available imply that TTS is unlikely to occur unless 
bow-riding odontocetes are exposed to airgun pulses much stronger than 
180 dB re 1 [mu]Pa rms (Southall et al. 2007).
    No cases of TTS are expected as a result of Statoil's proposed 
activities given the small size of the source, 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, and the mitigation 
measures proposed to be implemented during the survey described later 
in this document.
    There is no empirical evidence that exposure to pulses of airgun 
sound can cause PTS in any marine mammal, even with large arrays of 
airguns (see Southall et al., 2007). However, given the possibility 
that mammals close to an airgun array might incur TTS, there has been 
further speculation about the possibility that some individuals 
occurring very close to airguns might incur PTS. Single or occasional 
occurrences of mild TTS are not indicative of permanent auditory damage 
in terrestrial mammals. Relationships between TTS and PTS thresholds 
have not been studied in marine mammals, but are assumed to be similar 
to those in humans and other terrestrial mammals. That is, PTS might 
occur at a received sound level magnitudes higher than the level of 
onset TTS, or by repeated exposure to the levels that cause TTS. 
Therefore, by means of preventing the onset of TTS, it is highly 
unlikely that marine mammals could receive sounds strong enough (and 
over a sufficient duration) to cause permanent hearing impairment 
during the proposed marine surveys in the Chukchi Sea.
(5) Non-Auditory Physical Effects
    Non-auditory physical effects might occur in marine mammals exposed 
to strong underwater pulsed sound. Possible types of non-auditory 
physiological effects or injuries that theoretically might occur in 
mammals close to a strong sound source include stress, neurological 
effects, bubble formation, and other types of organ or tissue damage. 
Some marine mammal species (i.e., beaked whales) may be

[[Page 30115]]

especially susceptible to injury and/or stranding when exposed to 
strong pulsed sounds. However, there is no definitive evidence that any 
of these effects occur even for marine mammals in close proximity to 
large arrays of 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. 
The small airgun array proposed to be used by Statoil would only have 
190 and 180 dB distances of 35 and 125 m (115 and 410 ft), 
respectively.
    Therefore, it is unlikely that such effects would occur during 
Statoil's proposed surveys given the brief duration of exposure and the 
planned monitoring and mitigation measures described later in this 
document.
(6) Stranding and Mortality
    Marine mammals close to underwater detonations of high explosive 
can be killed or severely injured, and the auditory organs are 
especially susceptible to injury (Ketten et al. 1993; Ketten 1995). 
Airgun pulses are less energetic and their peak amplitudes have slower 
rise times. To date, there is no evidence that serious injury, death, 
or stranding by marine mammals can occur from exposure to airgun 
pulses, even in the case of large airgun arrays.
    However, in numerous past IHA notices for seismic surveys, 
commenters have referenced two stranding events allegedly associated 
with seismic activities, one off Baja California and a second off 
Brazil. NMFS has addressed this concern several times, and, without new 
information, does not believe that this issue warrants further 
discussion. For information relevant to strandings of marine mammals, 
readers are encouraged to review NMFS' response to comments on this 
matter found in 69 FR 74905 (December 14, 2004), 71 FR 43112 (July 31, 
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 
2006). In addition, a May-June 2008, stranding of 100-200 melon-headed 
whales (Peponocephala electra) off Madagascar that appears to be 
associated with seismic surveys is currently under investigation (IWC 
2009).
    It should be noted that strandings related to sound exposure have 
not been recorded for marine mammal species in the Beaufort and Chukchi 
seas. NMFS notes that in the Beaufort Sea, aerial surveys have been 
conducted by BOEMRE (formerly the Minerals Management Service or MMS) 
and industry during periods of industrial activity (and by MMS 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. 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 shallow hazards survey.

Potential Effects From Active Sonar Equipment on Marine Mammals

    Several active acoustic sources other than the four 10 in\3\ airgun 
have been proposed for Statoil's 2011 open water shallow hazards survey 
in the Chukchi Sea. The specifications of this sonar equipment (source 
levels and frequency ranges) are provided above. In general, the 
potential effects of this equipment on marine mammals are similar to 
those from the airgun, except the magnitude of the impacts is expected 
to be much less due to the lower intensity and higher frequencies. 
Estimated source levels from sonar equipment are discussed above. In 
some cases, due to the fact that the operating frequencies of some of 
this equipment (e.g., Multi-beam echosounder: Frequency at 200-400 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, various types of vessels will be used in the operations, 
including source vessel and vessel used for geotechnical soil 
investigations. 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). 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 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. However, noise from 
the vessel during geophysical soil investigation while operating the DP 
system using thrusters as well as the primary propeller(s) could 
produce noise levels higher than during normal operation of the vessel. 
Measurements of a vessel in DP mode with an active bow thruster were 
made in the Chukchi Sea in 2010 (Chorney et al. 2011). The resulting 
source level estimate was 175.9 dBrms re 1 [mu]Pa-m. Noise 
at this high level is not expected to be emitted continuously. It is 
emitted intermittently as the pitch is engaged to position the vessel.
    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 marine surveys, and during 
geotechnical soil investigation while operating the DP system.

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 other active acoustic sources. However, other potential impacts to 
the surrounding habitat from physical disturbance are also possible.

Potential Impacts on Prey Species

    With regard to fish as a prey source for cetaceans and pinnipeds, 
fish are known to hear and react to sounds and to use sound to 
communicate (Tavolga et al. 1981) and possibly avoid predators (Wilson 
and Dill 2002). Experiments have shown that fish can sense both the 
strength and direction of sound (Hawkins 1981). Primary factors 
determining whether a fish can sense a sound signal, and potentially 
react to it, are the frequency of the signal and the strength of the 
signal in relation to the natural background noise level.
    The level of sound at which a fish will react or alter its behavior 
is usually well above the detection level. Fish have been found to 
react to sounds when the sound level increased to about 20 dB above the 
detection level of 120

[[Page 30116]]

dB (Ona 1988); however, the response threshold can depend on the time 
of year and the fish's physiological condition (Engas et al. 1993). In 
general, fish react more strongly to pulses of sound rather than a 
continuous signal (Blaxter et al. 1981), and a quicker alarm response 
is elicited when the sound signal intensity rises rapidly compared to 
sound rising more slowly to the same level.
    Investigations of fish behavior in relation to vessel noise (Olsen 
et al. 1983; Ona 1988; Ona and Godo 1990) have shown that fish react 
when the sound from the engines and propeller exceeds a certain level. 
Avoidance reactions have been observed in fish such as cod and herring 
when vessels approached close enough that received sound levels are 110 
dB to 130 dB (Nakken 1992; Olsen 1979; Ona and Godo 1990; Ona and 
Toresen 1988). However, other researchers have found that fish such as 
polar cod, herring, and capeline are often attracted to vessels 
(apparently by the noise) and swim toward the vessel (Rostad et al. 
2006). Typical sound source levels of vessel noise in the audible range 
for fish are 150 dB to 170 dB (Richardson et al. 1995).
    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). However, by the time most 
bowhead whales reach the Chukchi Sea (October), they will likely no 
longer be feeding, or if it occurs it will be very limited. 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 that could cause 
significant or long-term consequences for individual marine mammals or 
their populations.

Proposed Mitigation

    In order to issue an incidental take authorization under Section 
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses.
    For the proposed Statoil open water shallow hazards survey in the 
Chukchi Sea, Statoil 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 shallow hazards survey 
activities.
    As part of the application, Statoil submitted to NMFS a Marine 
Mammal Monitoring and Mitigation Program (4MP) for its open water 
shallow hazards survey in the Chukchi Sea during the 2011 open-water 
season. The objectives of the 4MP are:
     To ensure that disturbance to marine mammals and 
subsistence hunts is minimized and all permit stipulations are 
followed,
     To document the effects of the proposed survey activities 
on marine mammals, and
     To collect baseline data on the occurrence and 
distribution of marine mammals in the study area.
    The 4MP may be modified or supplemented based on comments or new 
information received from the public during the public comment period 
or from the peer review panel (see the ``Monitoring Plan Peer Review'' 
section later in this document).

Mitigation Measures Proposed in Statoil's IHA Application

    For the proposed mitigation measures, Statoil listed the following 
protocols to be implemented during its shallow hazards survey in the 
Chukchi Sea.
(1) Sound Source Measurements
    As described above, previous measurements of similar airgun arrays 
in the Chukchi Sea were used to model the distances at which received 
levels are likely to fall below 120, 160, 180, and 190 dB re 1 [mu]Pa 
(rms) from the planned airgun sources. These modeled distances will be 
used as temporary safety radii until measurements of the airgun sound 
source are conducted. The measurements will be made at the beginning of 
the field season and the measured radii used for the remainder of the 
survey period.
    The objectives of the sound source verification measurements 
planned for 2011 in the Chukchi Sea will be to measure the distances at 
which broadband received levels reach 190, 180, 170, 160, and 120 
dBrms re 1 [mu]Pa for the airgun configurations that may be 
used during the survey activities. The configurations will include at 
least the full array (4 x 10 in\3\) and the operation of a single 10 
in\3\ airgun that will be used during power downs or very shallow 
penetration surveys. The measurements of airgun sounds will be made by 
an acoustics contractor at the beginning of the survey. The distances 
to the various radii will be reported as soon as possible after 
recovery of the equipment. The primary radii of concern will be the 190 
and 180 dB safety radii for pinnipeds and cetaceans, respectively, and 
the 160 dB disturbance radii. In addition to reporting the radii of 
specific regulatory concern, nominal distances to other sound isopleths 
down to 120 dBrms will be reported in increments of 10 dB. 
Sound levels during soil investigation operations will also be 
measured. However, source levels are not expected to be strong enough 
to require mitigation actions at the 190 dB or 180 dB levels.
    Data will be previewed in the field immediately after download from 
the hydrophone instruments. An initial sound source analysis will be 
supplied to NMFS and the vessel within 120 hours of completion of the 
measurements, if possible. The report will indicate the distances to 
sound levels based on fits of empirical transmission loss formulae to 
data in the endfire and broadside directions. A more detailed report 
will be issued to NMFS as part of the 90-day report following 
completion of the acoustic program.
(2) Safety and Disturbance Zones
    Under current NMFS guidelines, ``safety radii'' for marine mammal 
exposure to impulse sources are customarily defined as the distances 
within which received sound levels are >= 180 dBrms re 1 
[mu]Pa for cetaceans and >= 190 dBrms re 1 [mu]Pa for 
pinnipeds. These 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 safety radii (Richardson et al. 1995).
    Initial safety and disturbance radii for the sound levels produced 
by the planned airgun configurations have been estimated (Table 1). 
These radii will be used for mitigation purposes until results of 
direct measurements are available early during the exploration 
activities. The proposed surveys will use an airgun source composed of 
four

[[Page 30117]]

10-in\3\ airguns (total discharge volume of 40 in\3\) and a single 10 
in\3\ airgun. Underwater sound propagation from a similar 4 x 10-in\3\ 
airgun cluster and single 10 in\3\ was measured in 2009 (Reiser et al. 
2010). Those measurements resulted in 90th percentile propagation loss 
equations of RL = 218.0-17.5LogR-0.00061R for the 4 x 10 in\3\ airgun 
cluster and RL = 204.4-16.0LogR-0.00082R for the single 10 in\3\ airgun 
(where RL = received level and R = range). The estimated distances for 
the proposed 2011 activities are based on a 25% increase over 2009 
results (Table 1).
    In addition to the site surveys, Statoil plans to use a dedicated 
vessel to conduct geotechnical soil investigations. Sounds produced by 
the vessel and soil investigation equipment are not expected to be 
above 180 dB (rms). Therefore, mitigation related to acoustic impacts 
from these activities is not expected to be necessary.
    An acoustics contractor will perform direct measurements of the 
received levels of underwater sound versus distance and direction from 
the airguns and soil investigation vessel using calibrated hydrophones. 
The acoustic data will be analyzed as quickly as reasonably practicable 
in the field and used to verify and adjust the safety distances. The 
field report will be made available to NMFS and the MMOs within 120 hrs 
of completing the measurements. The mitigation measures to be 
implemented at the 190 and 180 dB sound levels will include power downs 
and shut downs as described below.

  Table 1--Distances to Specified Received Levels Measured From a 4 x 10 in\3\ Airgun Cluster and a Single 10-
 in\3\ Airgun on the Burger Prospect in 2009 as Reported by Reiser et al. (2010). The 2011 ``Pre-SSV'' Distances
    Are a Precautionary 25% Increase Above the Reported 2009 Results and Will Be Used by MMOs for Mitigation
                                   Purposes Until an SSV Is Completed in 2011
----------------------------------------------------------------------------------------------------------------
                                                                       Distance (m)
                                         -----------------------------------------------------------------------
  Received Levels (dB re 1 [mu]Pa rms)       Airgun cluster (4 x 10 in\3\)       Single airgun (1 x 10 in\3\)
                                         -----------------------------------------------------------------------
                                            2009 Results      2011 pre-SSV      2009 Results      2011 pre-SSV
----------------------------------------------------------------------------------------------------------------
190.....................................                39                50                 8                10
180.....................................               150               190                34                45
160.....................................             1,800             2,250               570               715
120.....................................            31,000            39,000            19,000            24,000
----------------------------------------------------------------------------------------------------------------

(3) Speed and Course Alterations
    If a marine mammal is detected outside the applicable safety radius 
and, based on its position and the relative motion, is likely to enter 
the safety radius, changes of the vessel's speed and/or direct course 
will be considered if this does not compromise operational safety. For 
marine seismic surveys using large streamer arrays, course alterations 
are not typically possible. However, for the smaller airgun array and 
streamer planned during the proposed site surveys, such changes may be 
possible. After any such speed and/or course alteration is begun, the 
marine mammal activities and movements relative to the survey vessel 
will be closely monitored to ensure that the marine mammal does not 
approach within the safety radius. If the mammal appears likely to 
enter the safety radius, further mitigative actions will be taken, 
including a power down or shut down of the airgun(s).
(4) Power Downs
    A power down for immediate mitigation purposes is the immediate 
reduction in the number of operating airguns such that the radii of the 
190 dBrms and 180 dBrms zones are decreased to 
the extent that an observed marine mammal(s) are not in the applicable 
safety zone of the full array. Power downs are also used while the 
vessel turns from the end of one survey line to the start of the next. 
During a power down, one airgun (or some other number of airguns less 
than the full airgun array) continues firing. The continued operation 
of one airgun is intended to (a) alert marine mammals to the presence 
of the survey vessel in the area, and (b) retain the option of 
initiating a ramp up to full operations under poor visibility 
conditions.
    The array will be immediately powered down whenever a marine mammal 
is sighted approaching close to or within the applicable safety zone of 
the full array, but is outside the applicable safety zone of the single 
mitigation airgun. Likewise, if a mammal is already within the safety 
zone when first detected, the airguns will be powered down immediately. 
If a marine mammal is sighted within or about to enter the applicable 
safety zone of the single mitigation airgun, it too will be shut down 
(see following section).
    Following a power down, operation of the full airgun array will not 
resume until the marine mammal has cleared the safety zone. The animal 
will be considered to have cleared the safety zone if it:
     Is visually observed to have left the safety zone of the 
full array, or
     Has not been seen within the zone for 15 min in the case 
of pinnipeds or small odontocetes, or
     Has not been seen within the zone for 30 min in the case 
of mysticetes or large odontocetes.
(5) Shut Downs
    The operating airgun(s) will be shut down completely if a marine 
mammal approaches or enters the then-applicable safety radius and a 
power down is not practical or adequate to reduce exposure to less than 
190 or 180 dBrms, as appropriate. In most cases, this means 
the mitigation airgun will be shut down completely if a marine mammal 
approaches or enters the estimated safety radius around the single 10 
in\3\ airgun while it is operating during a power down. Airgun activity 
will not resume until the marine mammal has cleared the safety radius. 
The animal will be considered to have cleared the safety radius as 
described above under power down procedures.
    A shut down of the borehole drilling equipment may be requested by 
MMOs if an animal is sighted approaching the vessel close enough to 
potentially interact with and be harmed by the soil investigation 
operation.
(6) Ramp Ups
    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of airguns firing until the full volume is achieved. The purpose 
of a ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds 
in the vicinity of the airguns and to provide the time for them to 
leave the area and thus avoid any

[[Page 30118]]

potential injury or impairment of their hearing abilities.
    During the proposed site survey program, the seismic operator will 
ramp up the airgun cluster slowly. Full ramp ups (i.e., from a cold 
start after a shut down, when no airguns have been firing) will begin 
by firing a single airgun in the array. The minimum duration of a shut-
down period, i.e., without air guns firing, which must be followed by a 
ramp up is typically the amount of time it would take the source vessel 
to cover the 180-dB safety radius. Given the small size of the planned 
airgun array, it is estimated that period to be about 1-2 minutes based 
on the modeling results described above and a survey speed of 4 kts.
    A full ramp up, after a shut down, will not begin until there has 
been a minimum of 30 minutes of observation of the safety zone by MMOs 
to assure that no marine mammals are present. The entire safety zone 
must be visible during the 30-minute lead-in to a full ramp up. If the 
entire safety zone is not visible, then ramp up from a cold start 
cannot begin. If a marine mammal(s) is sighted within the safety zone 
during the 30-minute watch prior to ramp up, ramp up will be delayed 
until the marine mammal(s) is sighted outside of the safety zone or the 
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for 
small odontocetes and pinnipeds, or 30 minutes for baleen whales and 
large odontocetes.
    During turns or brief transits between survey transects, one airgun 
will continue operating. The ramp-up procedure will still be followed 
when increasing the source levels from one airgun to the full 4-airgun 
cluster. 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, survey operations can resume upon entry 
to a new transect without the 30-minute watch period of the full safety 
radius required for a cold start. MMOs will be on duty whenever the 
airguns are firing during daylight, and during the 30-min periods prior 
to ramp-ups as well as during ramp-ups. Daylight will occur for 24 h/
day until mid-August, so until that date MMOs will automatically be 
observing during the 30-minute period preceding a ramp up. Later in the 
season, MMOs will be called to duty at night to observe prior to and 
during any ramp ups. The survey operator and MMOs will maintain records 
of the times when ramp-ups start, and when the airgun arrays reach full 
power.

Additional Mitigation Measures Proposed by NMFS

    Besides Statoil's proposed mitigation measures discussed above, 
NMFS proposes the following additional protective measures to address 
some uncertainties regarding the impacts of bowhead cow-calf pairs and 
aggregations of whales from shallow hazards surveys. Specifically, NMFS 
proposes that
     A 160-dB vessel monitoring zone for large whales will be 
established and monitored in the Chukchi Sea during all shallow hazards 
surveys. Whenever an aggregation of bowhead whales or gray whales (12 
or more whales of any age/sex class that appear to be engaged in a non-
migratory, significant biological behavior (e.g., feeding, 
socializing)) are observed during a vessel monitoring program within 
the 160-dB safety zone around the survey operations, the survey 
activity will not commence or will shut down, until they are no longer 
present within the 160-dB safety zone of shallow hazards surveying 
operations.
    Furthermore, NMFS proposes the following measures be included in 
the IHA, if issued, in order to ensure the least practicable impact on 
the affected species or stocks:
    (1) All vessels should reduce speed when within 300 yards (274 m) 
of whales, and those vessels capable of steering around such groups 
should do so. Vessels may not be operated in such a way as to separate 
members of a group of whales from other members of the group;
    (2) Avoid multiple changes in direction and speed when within 300 
yards (274 m) of whales; and
    (3) When weather conditions require, such as when visibility drops, 
support vessels must adjust speed (increase or decrease) and direction 
accordingly to avoid the likelihood of injury to whales.

Mitigation Conclusions

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

Proposed Monitoring and Reporting

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

Monitoring Measures Proposed in Statoil's IHA Application

    The monitoring plan proposed by Statoil can be found in the 4MP. 
The plan may be modified or supplemented based on comments or new 
information received from the public during the public comment period 
or from the peer review panel (see the ``Monitoring Plan Peer Review'' 
section later in this document). A summary of the primary components of 
the plan follows.
(1) Vessel-Based MMOs
    Vessel-based monitoring for marine mammals will be done by trained 
MMOs throughout the period of marine survey activities. MMOs will 
monitor the occurrence and behavior of marine mammals near the survey 
vessel during all daylight periods during operation and during most 
daylight periods when airgun operations are not occurring. MMO duties 
will include watching for and identifying marine mammals, recording 
their numbers, distances, and reactions to the survey operations, and 
documenting ``take by harassment'' as defined by NMFS.
    A sufficient number of MMOs will be required onboard the survey 
vessel to meet the following criteria: (1) 100% monitoring coverage 
during all periods of survey operations in daylight; (2) maximum of 4 
consecutive hours on watch per MMO; and (3) maximum of

[[Page 30119]]

12 hours of watch time per day per MMO.
    MMO teams will consist of Inupiat observers and experienced field 
biologists. An experienced field crew leader will supervise the MMO 
team onboard the survey vessel. The total number of MMOs may decrease 
later in the season as the duration of daylight decreases. Statoil 
currently plans to have 5 MMOs aboard the site survey vessel and 3 MMOs 
aboard the soil investigation vessel, with the potential of reducing 
the number of MMOs later in the season as daylight periods decrease in 
length.
    Crew leaders and most other biologists serving as observers in 2011 
will 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.
    Observers will complete a two or three-day training session on 
marine mammal monitoring, to be conducted shortly before the 
anticipated start of the 2011 open-water season. The training 
session(s) will be conducted by qualified marine mammalogists with 
extensive crew-leader experience during previous vessel-based 
monitoring programs. A marine mammal observers' handbook, adapted for 
the specifics of the planned survey program will be reviewed as part of 
the training.
    Primary objectives of the training include:
     Review of the marine mammal monitoring plan for this 
project, including any amendments specified by NMFS in the IHA (if 
issued), by USFWS or Bureau of Ocean Energy Management, Regulation and 
Enforcement (BOEMRE), or by other agreements in which Statoil may elect 
to participate;
     Review of marine mammal sighting, identification, and 
distance estimation methods;
     Review of operation of specialized equipment (reticle 
binoculars, night vision devices, and GPS system);
     Review of, and classroom practice with, data recording and 
data entry systems, including procedures for recording data on marine 
mammal sightings, monitoring operations, environmental conditions, and 
entry error control. These procedures will be implemented through use 
of a customized computer database and laptop computers;
     Review of the specific tasks of the Inupiat Communicator.
    The observer(s) will watch for marine mammals from the best 
available vantage point on the survey vessels, typically the bridge. 
The observer(s) will scan systematically with the unaided eye and 7x50 
reticle binoculars, supplemented with 20x60 image-stabilized Zeiss 
Binoculars or Fujinon 25x150 ``Big-eye'' binoculars, and night-vision 
equipment when needed (see below). Personnel on the bridge will assist 
the marine mammal observer(s) in watching for marine mammals.
    Information to be recorded by marine mammal observers will include 
the same types of information that were recorded during recent 
monitoring programs associated with Industry activity in the Arctic 
(e.g., Ireland et al. 2009). When a mammal sighting is made, the 
following information about the sighting will be recorded:
    (A) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from the MMO, apparent reaction to 
activities (e.g., none, avoidance, approach, paralleling, etc.), 
closest point of approach, and behavioral pace;
    (B) Time, location, speed, activity of the vessel, sea state, ice 
cover, visibility, and sun glare; and
    (C) The positions of other vessel(s) in the vicinity o