[Federal Register Volume 75, Number 95 (Tuesday, May 18, 2010)]
[Notices]
[Pages 27708-27731]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-11860]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XV09


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Open Water Marine Survey Program in 
the Beaufort and Chukchi Seas, 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 Shell Offshore Inc. (Shell) 
for an Incidental Harassment Authorization (IHA) to take marine 
mammals, by harassment, incidental to a proposed open water marine 
survey program in the Beaufort and Chukchi Seas, Alaska, between July 
and October 2010. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an IHA to Shell to 
take, by Level B harassment only, eight species of marine mammals 
during the specified activity.

DATES: Comments and information must be received no later than June 17, 
2010.

ADDRESSES: Comments on the application should be addressed to Michael 
Payne, Chief, Permits, Conservation and Education Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910. The mailbox address for providing e-
mail comments is [email protected]. NMFS is not responsible for e-
mail comments sent to addresses other than the one provided here. 
Comments sent via e-mail, including all attachments, must not exceed a 
10-megabyte file size.
    Instructions: All comments received are a part of the public record 
and will

[[Page 27709]]

generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information 
(for example, name, address, etc.) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    A copy of the application used in this document may be obtained by 
writing to the address specified above, telephoning the contact listed 
below (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited 
in this notice may also be viewed, by appointment, during regular 
business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: 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 December 24, 2009, from Shell for 
the taking, by harassment, of marine mammals incidental to several 
marine surveys designed to gather data relative to site clearance and 
shallow hazards, ice gouge, and strudel scour in selected areas of the 
Beaufort Sea and ice gouge in the Chukchi Sea, Alaska. These surveys 
are continuations of those performed by Shell in the Beaufort Sea 
beginning in 2006, and in the Chukchi Sea in 2008. After addressing 
comments from NMFS, Shell modified its application and submitted a 
revised application on April 19, 2010. The April 19, 2009, application 
is the one available for public comment (see ADDRESSES) and considered 
by NMFS for this proposed IHA.
    Site clearance and shallow hazards surveys will evaluate the 
seafloor, and shallow sub seafloor at prospective exploration drilling 
locations, focusing on the depth to seafloor, topography, the potential 
for shallow faults or gas zones, and the presence of archaeological 
features. The types of equipment used to conduct these surveys use low 
level energy sources focused on limited areas in order to characterize 
the footprint of the seafloor and shallow sub seafloor at prospective 
drilling locations. Ice gouge surveys will determine the depth and 
distribution of ice gouges into the seabed. Ice gouge surveys use low-
level energy sources similar to the site clearance and shallow hazards.
    Shell intends to conduct these marine surveys during the 2010 
Arctic open-water season (July through October). Impacts to marine 
mammals may occur from noise produced by various active acoustic 
sources used in the surveys.

Description of the Specified Activity

    Shell plans to complete the following surveys during the 2010 open-
water season:

 Beaufort Sea Site Clearance and Shallow Hazards Surveys
 Beaufort Sea Marine Surveys
[cir] Ice Gouge Survey
[cir] Strudel Scour Survey
 Chukchi Sea Marine Surveys
[cir] Ice Gouge Survey
    Each of these individual surveys will require marine vessels to 
accomplish the work. Shell states that these marine surveys will be 
conducted between July and October 2010, however, ice and weather 
conditions will influence the exact dates and locations marine vessel 
survey operations can be conducted.

1. Beaufort Sea Site Clearance and Shallow Hazards Surveys

    Shell's proposed site clearance and shallow hazards surveys are to 
gather data on: (1) Bathymetry, (2) seabed topography and other seabed 
characteristics (e.g., boulder patches), (3) potential geohazards 
(e.g., shallow faults and shallow gas zones), and (4) the presence of 
any archeological features (e.g., shipwrecks). Site clearance and 
shallow hazards surveys can be accomplished by one vessel with acoustic 
sources. No other vessels are necessary to accomplish the proposed 
work.
    The focus of this activity will be on Shell's existing leases in 
Harrison Bay in the central Beaufort Sea. Actual locations of site 
clearance and shallow hazards surveys within Harrison Bay have not been 
definitively set as of this date, although these will occur on the 
Outer Continental Shelf (OCS) lease blocks in Harrison Bay located in 
the Beaufort Sea shown on Figure 1 of Shell's IHA application. The site 
clearance and shallow hazards surveys will be conducted within an area 
of approximately 216 mi \2\ (558 km \2\) north of Thetis Island more 
than 3 mi (4.8 km) to approximately 20 mi (33 km) offshore. 
Approximately 63 mi (162.7 km) of the data acquisition is planned 
within this general area. The survey track line is approximately 351.5 
mi \2\ (565 km \2\). The average depth of the survey area ranges from 
35 to 85 ft (10.7 to 26 m).
    Ice and weather permitting, Shell is proposing to conduct site 
clearance and shallow hazards surveys within the timeframe of July 2010 
through October 2010. The actual survey time is expected to take 30 
days.
    The vessel that will be conducting this activity has not been 
determined at this point, but will be similar to the R/V Mt. Mitchell 
which is the vessel that was used for surveys in the Chukchi Sea in 
2009. The R/V Mt. Mitchell is a diesel powered-vessel, 70 m (231 ft) 
long, 12.7 m (42 ft) wide, with a 4.5 m (15 ft) draft.

[[Page 27710]]

    It is proposed that the following acoustic instrumentation, or 
something similar, be used.
     Deep Penetration Profiler, (40 cu-in airgun source with 
48-channel streamer) and Medium Penetration Profiler, (40 cu-in airgun 
source with 24-channel streamer):
    The deep and medium penetration profiler and the medium penetration 
profiler are the major active acoustic sources used in the site 
clearance and shallow hazards surveys. The modeled source level is 
estimated at 217 dB re 1 [mu]Pa rms. The 120, 160, 180, and 190 dB re 1 
[mu]Pa rms received level isopleths are estimated at 14,900 m, 1,220 m, 
125 m, and 35 m from the source, respectively.
     Dual-frequency side scan sonar, (100-400 kHz or 300-600 
kHz):
    Based on the 2006 Shell's 90-day report, the source level of this 
active acoustic source when operated at 190 and 240 kHz is 
approximately 225 dB re 1 [mu]Pa rms. Due to its high frequency range, 
NMFS does not consider its acoustic energy would be strong enough to 
cause impacts to marine mammals beyond a couple of hundred meters from 
the source.
     Single beam Echo Sounder, (high: 100-340 kHz, low: 24-50 
kHz):
    This echo sounder is a typical ``fathometer'' or ``fish-finder'' 
that is widely used in most recreational or fishing vessels. Source 
levels for these types of units are typically in the range of 180-200 
dB re 1 [mu]Pa rms. Using a spherical spreading model, the 160 dB 
isopleth is estimated at 100 m from the source for the lower range of 
the acoustic signals. For the higher range of the signal, due to the 
higher absorption coefficients, the 160 dB isopleth is expected to be 
under 100 m from the source.
     Multi-beam Echo Sounder, (240 kHz):
    Since the output frequency from this echo sounder is above the 
upper limit of marine mammal hearing range, NMFS does not believe this 
equipment would affect marine mammals.
     Shallow Sub-Bottom Profiler, (2-12 kHz):
    Information regarding this active acoustic source on two vessels 
(Alpha Helix and Henry C.) was provided in Shell's 2008 90-day open 
water marine survey monitoring report. For the Alpha Helix measurement, 
at 3.5 kHz, the source level for the shallow sub-bottom profiler was 
193.8 dB re 1 [mu]Pa rms, and its 120, 160, 180, and 190 dB re 1 [mu]Pa 
rms isopleths were determined to be 310 m, 14 m, 3 m, and 1 m from the 
source, respectively. For the Henry C. measurement, at 3.5 kHz, the 
source level of the similar profiler was measured at 167.2 dB re 1 
[mu]Pa rms, and its 120 and 160 dB re 1 [mu]Pa rms isopleths were 
determined to be 980 m and 3 m, respectively.

2. Beaufort Sea Marine Surveys

    Two marine survey activities are proposed for the Beaufort Sea: (1) 
Ice gouge survey, and (2) strudel scour survey. Shell continues to 
conduct these types of marine surveys annually over a few years to 
enhance baseline and statistical understanding of the formation, 
longevity, and temporal distribution of sea floor features and baseline 
environmental and biologic conditions. Marine surveys for ice gouge and 
strudel scour surveys can be accomplished by one vessel for each. No 
other vessels are necessary to accomplish the proposed work.
    The proposed ice gouge surveys will be conducted in both State of 
Alaska waters including Camden Bay, and the Federal waters of the OCS 
in the Beaufort Sea near Pt. Thomson ranging from near shore to 
approximately 37 mi (59.5 km) offshore. The water depth in the ice 
gouging survey area ranges between 15 to 120 ft (4.5 to 36.6 m), and 
the surveys will be conducted within an area of 1,950 mi \2\ (5,036 km 
\2\) with a survey track line of approximately 1,276 mi (2,050 km, See 
Figure 2 of Shell's IHA application).
    The proposed strudel scour survey will occur in State of Alaska 
waters in Pt. Thomson ranging from near shore to 3 mi (4.8 km) 
offshore. The water depth ranges from 3 to 20 ft (0.9 to 6.1 m). The 
strudel scour survey will be conducted in an area of approximately 140 
mi \2\ (361.5 km \2\). The survey track line is approximately 124 mi 
(200 km).
    Ice and weather permitting, Shell is proposing to conduct this work 
within the timeframe of July 2010 through October 2010. The actual 
survey time is expected to take 45 days.

Ice Gouge Survey

    As part of the feasibility study for Shell's Alaskan prospects a 
survey is required to identify and evaluate seabed conditions. Ice 
gouging is created by ice keels, which project from the bottom of 
moving ice and gouge into seafloor sediment. Ice gouge features are 
mapped, and by surveying each year, new gouges can be identified. The 
ice gouge information is used to aid in predicting the prospect of, 
orientation, depth, and frequency of future ice gouges. Ice gouge 
information is required for the design of potential pipelines and for 
the design of pipeline trenching and installation equipment.
    The 2010 ice gouge surveys will be conducted using the conventional 
survey method where the acoustic instrumentation will be towed behind 
the survey vessel, or possibly with the use of an Autonomous Underwater 
Vehicle (AUV). The same acoustic instrumentation will be used during 
both AUV and the conventional survey methods. The AUV is a self-
propelled autonomous vehicle that will be equipped with acoustic 
instrumentation and programmed for remote operation over the seafloor 
where the ice gouge survey is to be conducted, and the vehicle is 
launched and retrieved from a marine vessel.
    For the survey operations, the AUV will be launched from the stern 
of a vessel and will survey the seafloor close to the vessel. The 
vessel will transit an area, with the AUV surveying the area behind the 
vessel. The AUV also has a Collision Avoidance System and operates 
without a towline that reduces potential impact to marine mammals (such 
as entanglement). Using bathymetric sonar or multibeam echo sounder the 
AUV can record the gouges on the seafloor surface caused by ice keels. 
The sub-bottom profiler can record layers beneath the surface to about 
20 feet (6 m). The AUV is more maneuverable and able to complete 
surveys quicker than a conventional survey. This reduces the duration 
that vessels producing sound must operate. The proposed ice gouge 
survey in the Beaufort Sea is expected to last for 45 days.
    The vessel that will be used for ice gouging surveys has not been 
selected, but it is anticipated that the vessel would be similar to the 
R/V Mt. Mitchell, which is 70 m (231 ft) long, 12.7 m (42 ft) wide, and 
4.5 m (15 ft) draft.
    It is proposed that the following acoustic instrumentation, or 
something similar, be used.
     Dual Frequency subbottom profiler; (2 to 7 kHz or 8 to 23 
kHz):
    Information regarding this active acoustic source on Henry C. was 
provided in Shell's 2006 and 2007 90-day open water marine survey 
monitoring reports. In the 2006 report, at 2-7 and 8-23 kHz, the source 
level was estimated at 184.6 dB re 1 [mu]Pa rms, and its 120, 160, and 
180 dB re 1 [mu]Pa rms isopleths were determined to be 456 m, 7 m, and 
2 m from the source, respectively. In the 2007 report, at 2-7 kHz, the 
source level was estimated at 161.1 dB re 1 [mu]Pa rms, and its 120 and 
160 dB re 1 [mu]Pa rms isopleths were determined to be 260 m and 1 m, 
respectively.
     Multibeam Echo Sounder (240 kHz) and Side-scan sonar 
system (190 to 210 kHz):

[[Page 27711]]

    Since the output frequencies from these acoustic instruments are 
above the upper-limits of marine mammal hearing range, NMFS does not 
believe they would affect marine mammals.
    Because of the low source levels of the sub-bottom profiler and the 
high-frequency nature of the multi-beam echo sounder used in the 
proposed ice gouge survey, NMFS believes it unlikely that a marine 
mammal would be taken by this activity.

Strudel Scour Survey

    During the early melt on the North Slope, the rivers begin to flow 
and discharge water over the coastal sea ice near the river deltas. 
That water flows down holes in the ice (``strudels'') and scours the 
seafloor. These areas are called ``strudel scours.'' Information on 
these features is required for prospective pipeline planning. Two 
proposed activities are required to gather this information: Aerial 
survey via helicopter overflights during the melt to locate the 
strudels; and strudel scour marine surveys to gather bathymetric data. 
The overflights investigate possible sources of overflood water and 
will survey local streams that discharge in the vicinity of Point 
Thomson including the Staines River, which discharges to the east into 
Flaxman Lagoon, and the Canning River, which discharges to the east 
directly into the Beaufort Sea. These helicopter overflights will occur 
during late May/early June 2010 and, weather permitting, should take no 
more than two days. There are no planned landings during these 
overflights other than at the Deadhorse or Kaktovik airports.
    Areas that have strudel scour identified during the aerial survey 
will be verified and surveyed with a marine vessel after the breakup of 
nearshore ice. The vessel has not been determined, however, it is 
anticipated that it will be the diesel-powered R/V Annika Marie which 
has been utilized 2006 through 2008 and measures 13.1 m (43 ft) long, 
or similar vessel.
    This proposed activity is not anticipated to take more than 5 days 
to conduct. The operation is conducted in the shallow water areas near 
the coast in the vicinity of Point Thomson. This vessel will use the 
following equipment:
     Multibeam Echo Sounder (240 kHz) and Side-scan sonar 
system (190 to 210 kHz):
    Since the output frequencies from these acoustic instruments are 
above the upper-limits of marine mammal hearing range, NMFS does not 
believe they would affect marine mammals.
     Single Beam Bathymetric Sonar:
    Source levels for these types of units are typically in the 180-230 
dB range, somewhat lower than multibeam or side scan sonars. A unit 
used during a previous survey had a source level (at high power) of 215 
dB re 1 [mu]Pa (0-peak) and a standard operating frequency of 200 kHz. 
Since the output frequencies from these acoustic instruments are above 
the upper-limits of marine mammal hearing range, NMFS does not believe 
they would affect marine mammals.

3. Chukchi Sea Marine Survey--Ice Gouge Survey

    Shell proposes one marine survey activity for the Chukchi Sea in 
2010. Shell intends to conduct ice gouge surveys annually over a few 
years to enhance baseline and statistical understanding of the 
formation, longevity, and temporal distribution of sea floor features 
and baseline environmental and biologic conditions. The ice gouge 
survey can be accomplished by one vessel. No other vessels are 
necessary to accomplish the proposed work.
    The proposed ice gouge surveys will be conducted in both State of 
Alaska waters and the Federal waters of the OCS in the Chukchi Sea. 
Actual locations of the ice gouge surveys have not been definitively 
set as of this date, although these will occur within the area outlined 
in Figure 4 of the IHA application. The water depth of the ice gouging 
survey ranges between 20 to 120 ft (6.1 to 36.6 m), and the surveys 
will take in an area of 21,954 mi \2\ (56,965 km \2\), with a survey 
track line of approximately 1,539 mi (2,473 km). This activity is 
proposed to be conducted within the timeframe of July through October 
2010. The total program will last a maximum of 60 days, excluding 
downtime due to ice, weather and other unforeseen delays, and should be 
complete by the end of October 2010.
    The equipment and method used to conduct the ice gouge survey in 
the Chukchi Sea will be the same as that used in the Beaufort Sea. 
Because of the low source levels of the sub-bottom profiler and the 
high-frequency nature of the multi-beam echo sounder used in the 
proposed ice gouge survey, NMFS believes it unlikely that a marine 
mammal would be taken by this activity.
Description of Marine Mammals in the Area of the Specified Activity
    Nine cetacean and four pinniped species under NMFS jurisdiction 
could occur in the general area of Shell's open water marine survey 
areas in the Beaufort and Chukchi Seas. The species most likely to 
occur in the general area near Harrison Bay in the Alaskan Beaufort Sea 
include two cetacean species: beluga (Delphinapterus leucas) and 
bowhead whales (Balaena mysticetus) and three seal species: ringed 
(Phoca hispida), spotted (P. largha), and bearded seals (Erignathus 
barbatus). Most encounters are likely to occur in nearshore shelf 
habitats or along the ice edge. The marine mammal species that is 
likely to be encountered most widely (in space and time) through-out 
the period of the planned shallow hazards surveys is the ringed seal. 
Encounters with bowhead and beluga whales are expected to be limited to 
particular regions and seasons, as discussed below.
    Other marine mammal species that have been observed in the Beaufort 
and Chukchi Seas but are less frequent or uncommon in the project area 
include harbor porpoise (Phocoena phocoena), narwhal (Monodon 
monoceros), killer whale (Orcinus orca), fin whale (Balaenoptera 
physalus), minke whale (B. acutorostrata), humpback whale (Megaptera 
novaeangliae), gray whale (Eschrichtius robustus), 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 marine surveys. 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). Point Barrow, 
Alaska, is the approximate northeastern extent of the harbor porpoise's 
regular range (Suydam and George 1992), though there are extralimital 
records east to the mouth of the Mackenzie River in the Northwest 
Territories, Canada, and recent sightings in the Beaufort Sea in the 
vicinity of Prudhoe Bay during surveys in 2007 and 2008 (Christie et 
al. 2009). Monnett and Treacy (2005) did not report any harbor porpoise 
sightings during aerial surveys in the Beaufort Sea from 2002 through 
2004. Humpback, fin, and minke whales have recently been sighted in the 
Chukchi Sea but very rarely in the Beaufort Sea. Greene et al. (2007) 
reported and photographed a humpback whale cow/calf pair east of Barrow 
near Smith Bay in 2007, which is the first known occurrence of 
humpbacks in the Beaufort Sea. Savarese et al. (2009) reported one 
minke whale sighting in

[[Page 27712]]

the Beaufort Sea in 2007 and 2008. Ribbon seals do not normally occur 
in the Beaufort Sea; however, two ribbon seal sightings were reported 
during vessel-based activities near Prudhoe Bay in 2008 (Savarese et 
al. 2009).
    The bowhead 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.
    Shell'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 2009 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2009.pdf.

Potential Effects of the Specified Activity on Marine Mammals

    Operating a variety of active acoustic sources such as airguns, 
side-scan sonars, echo-sounders, and sub-bottom profilers for site 
clearance and shallow hazard surveys, ice gouge, and strudel surveys 
can impact marine mammals in a variety of ways.

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 seismic vessels often show no 
apparent response. That is often true even in cases when the pulsed 
sounds must be readily audible to the animals based on measured 
received levels and the hearing sensitivity of 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 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

[[Page 27713]]

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 [micro]Pa rms. The established 180- 
and 190-dB re 1 [micro]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 to imply that TTS is 
unlikely to occur unless bow-riding odontocetes are exposed to airgun 
pulses much stronger than 180 dB re 1 [micro]Pa rms (Southall et al. 
2007).
    No cases of TTS are expected as a result of Shell'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 Beaufort and Chukchi Seas.
(5) Non-auditory Physical Effects
    Non-auditory physical effects might occur in marine mammals exposed 
to strong underwater pulsed sound. Possible types of non-auditory 
physiological effects or injuries that theoretically might occur in 
mammals close to a strong sound source include stress, neurological 
effects, bubble formation, and other types of organ or tissue damage. 
Some marine mammal species (i.e., beaked whales) may be especially 
susceptible to injury and/or stranding when exposed to strong pulsed 
sounds. However, there is no definitive evidence that any of these 
effects occur even for marine mammals in close proximity to large 
arrays of 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 Shell 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 
Shell'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;

[[Page 27714]]

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 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 proposed seismic 
survey.

Potential Effects From Active Sonar Equipment on Marine Mammals

    Several active acoustic sources other than the 40 cu-in airgun have 
been proposed for Shell's 2010 open water marine surveys in the 
Beaufort and Chukchi Seas. The specifications of these sonar equipments 
(source levels and frequency ranges) are provided above. In general, 
the potential effects of these equipments 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 and zones of influence 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 echo 
sounder: frequency at 240 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 vessels and support vessels. 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). 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.
    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. Icebreakers contribute greater sound 
levels during ice-breaking activities than ships of similar size during 
normal operation in open water (Richardson et al. 1995). This higher 
sound production results from the greater amount of power and propeller 
cavitation required when operating in thick ice. Source levels from 
various vessels would be empirically measured before the start of 
marine 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 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 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). Reactions of zooplanktoners to 
sound are, for the most part, not known. Their abilities to move 
significant distances

[[Page 27715]]

are limited or nil, depending on the type of animal. A reaction by 
zooplankton to sounds produced by the marine survey program 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 near the airgun source, which is 
expected to be a very small area. Impacts on zooplankton behavior are 
predicted to be negligible, and that would translate into negligible 
impacts on feeding mysticetes.

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 Shell open water marine surveys in the Beaufort 
and Chukchi Sea, Shell 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 survey activities.
    As part of the application, Shell submitted to NMFS a Marine Mammal 
Monitoring and Mitigation Program (4MP) for its shallow hazards survey 
activities in the Beaufort Sea during the 2010 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 Shell's IHA Application

    For the proposed mitigation measures, Shell listed the following 
protocols to be implemented during its marine surveys in the Beaufort 
Sea.
(1) Sound Source Measurements
    As described above, previous measurements of airguns in the 
Harrison Bay area were used to model the distances at which received 
levels are likely to fall below 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 2010 in the Beaufort Sea will be (1) to measure the 
distances in the broadside and endfire directions at which broadband 
received levels reach 190, 180, 170, 160, and 120 dB re 1 [mu]Pa (rms) 
for the energy source array combinations that may be used during the 
survey activities. The configurations will include at least the full 
array and the operation of a single source that will be used during 
power downs. The measurements of energy source array sounds will be 
made at the beginning of the survey and 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 dB re 1 [mu]Pa (rms) will be reported in increments of 10 dB.
    Data will be previewed in the field immediately after download from 
the ocean bottom hydrophone (OBH) instruments. An initial sound source 
analysis will be supplied to NMFS and the airgun operators within 120 
hours of completion of the measurements, if possible. The report will 
indicate the distances to sound levels between 190 dB re 1 [mu]Pa (rms) 
and 120 dB re 1 [mu]Pa (rms) based on fits of empirical transmission 
loss formulae to data in the endfire and broadside directions. The 120-
hour report findings will be based on analysis of measurements from at 
least three of the OBH systems. A more detailed report including 
analysis of data from all OBH systems will be issued to NMFS as part of 
the 90-day report following completion of the acoustic program.
    Airgun pressure waveform data from the OBH systems will be analyzed 
using JASCO's suite of custom signal processing software that 
implements the following data processing steps:
     Energy source pulses in the OBH recordings are identified 
using an automated detection algorithm. The algorithm also chooses the 
90% energy time window for rms sound level computations.
     Waveform data is converted to units of [mu]Pa using the 
calibrated acoustic response of the OBH system. Gains for frequency-
dependent hydrophone sensitivity, amplifier and digitizer are applied 
in this step.
     For each pulse, the distance to the airgun array is 
computed from GPS deployment positions of the OBH systems and the time 
referenced DGPS navigation logs of the survey vessel.
     The waveform data are processed to determine flat-weighted 
peak sound pressure level (PSPL), rms SPL and SEL.
     Each energy pulse is Fast Fourier Transformed (FFT) to 
obtain 1-Hz spectral power levels in 1-second steps.
     The spectral power levels are integrated in standard 1/3-
octave bands to obtain band sound pressure levels (BSPL) for bands from 
10 Hz to 20 kHz. Both un-weighted and M-weighted (frequency weighting 
based on hearing sensitivities of four marine mammal functional hearing 
groups, see Southall et al. (2007) for a review) SPL's for each airgun 
pulse may be computed in this step for species of interest.
    The output of the above data processing steps includes listings and 
graphs of airgun array narrow band and broadband sound levels versus 
range, and spectrograms of shot waveforms at specified ranges. Of 
particular importance are the graphs of level versus range that are 
used to compute representative radii to specific sound level 
thresholds.
(2) Safety and Disturbance Zones
    Under current NMFS guidelines, ``safety radii'' for marine mammals 
exposure to impulse sources are customarily defined as the distances 
within which received sound levels are >=180 dB re 1 [mu]Pa (rms) for 
cetaceans and >=190 dB re 1 [mu]Pa (rms) 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 SPL received at higher levels might have some such 
effects. Disturbance or behavioral effects to marine mammals from 
underwater sound may occur after exposure to sound at distances greater 
than the safety radii (Richardson et al. 1995).
    Initial safety and disturbance radii for the sound levels produced 
by the survey activities have been modeled. These

[[Page 27716]]

radii will be used for mitigation purposes until results of direct 
measurements are available early during the exploration activities. The 
planned survey will use an airgun source composed of either 40 in \3\ 
airguns or 1 x 20-in \3\ plus 2 x 10-in \3\ airguns. The total source 
volume will be 4 x 10 in \3\. Measurements of a 2 x 10-in \3\ airgun 
array used in 2007 were reported by Funk et al. (2008). These 
measurements were used as the basis for modeling both of the potential 
airgun arrays that may be used in 2010. The modeling results showed 
that the 40 in \3\ array is likely to produce sounds that propagate 
further than the alternative array, so those results were used to 
estimate ``takes by harassment'' in Shell's IHA application and will 
also be used during initial survey activities prior to in-field sound 
source measurements. The modeled 190 and 180 dB distances from a 40 
cubic inch array were 35 and 125 m, respectively. Because this is a 
modeled estimate, but based on similar measurements at the same 
location, the estimated distances for initial safety radii were only 
increased by a factor of 1.25 instead of a typical 1.5 factor. This 
results in a 190-dB distance of 44 m and a 180-dB distance of 156 m.
    A single 10-in \3\ airgun will be used as a mitigation gun during 
turns or if a power down of the full array is necessary due to the 
presence of a marine mammal close to the vessel. Underwater sound 
propagation of a 10-in \3\ airgun was measured near Harrison Bay in 
2007 and results were reported in Funk et al. (2008). The 190 dB and 
180 dB distances from those measurements, 5 m and 20 m respectively, 
will be used as the pre-sound source measurement safety zones during 
use of the single mitigation gun.
    An acoustics contractor will perform the direct measurements of the 
received levels of underwater sound versus distance and direction from 
the energy source arrays using calibrated hydrophones. The acoustic 
data will be analyzed as quickly as reasonably practicable in the field 
and used to verify (and if necessary adjust) the safety distances. The 
mitigation measures to be implemented at the 190 and 180 dB sound 
levels will include power downs and shut downs as described below.
(3) Power Downs and Shut Downs
    A power-down is the immediate reduction in the number of operating 
energy sources from all firing to some smaller number. A shutdown is 
the immediate cessation of firing of all energy sources. The arrays 
will be immediately powered down whenever a marine mammal is sighted 
approaching close to or within the applicable safety zone of the full 
arrays but is outside or about to enter the applicable safety zone of 
the single mitigation source. If a marine mammal is sighted within the 
applicable safety zone of the single mitigation airgun, the entire 
array will be shut down (i.e., no sources firing). Although MMOs will 
be located on the bridge ahead of the center of the airgun array, the 
shutdown criterion for animals ahead of the vessel will be based on the 
distance from the bridge (vantage point for MMOs) rather than from the 
airgun array--a precautionary approach. For marine mammals sighted 
alongside or behind the airgun array, the distance is measured from the 
array.
    Following a power-down or shutdown, operation of the airgun array 
will not resume until the marine mammal has cleared the applicable 
safety zone. The animal will be considered to have cleared the safety 
zone if it:
     Is visually observed to have left the safety zone;
     Has not been seen within the zone for 15 min in the case 
of small odontocetes and pinnipeds; or
     Has not been seen within the zone for 30 min in the case 
of mysticetes.
(4) Ramp Ups
    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a stepwise 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 potential injury 
or impairment of their hearing abilities.
    During the proposed shallow hazards 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. The minimum duration 
of a shut-down period, i.e., without air guns firing, which must be 
followed by a ramp up typically is the amount of time it would take the 
source vessel to cover the 180-dB safety radius. The actual time period 
depends on ship speed and the size of the 180-dB safety radius. That 
period is estimated to be about 1-2 minutes based on the modeling 
results described above and a survey speed of 4 knots.
    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 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 and transit between seismic transects, at least one 
airgun will remain operational. The ramp-up procedure still will be 
followed when increasing the source levels from one airgun to the full 
arrays. 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 operations can resume upon entry 
to a new transect without a full ramp up and the associated 30-minute 
lead-in observations. 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 out at night to observe prior to and during any ramp up. 
The seismic 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 Shell's proposed mitigation measures discussed above, NMFS 
proposes the following additional protective measures to address some 
uncertainties regarding the impacts to bowhead cow-calf pairs and 
aggregations of whales from seismic surveys. Specifically, NMFS 
proposes that:
     For seismic activities (including shallow hazards and site 
clearance and other marine surveys where active acoustic sources will 
be employed) in the Beaufort Sea after August 25, a 120-dB monitoring 
(safety) zone for bowhead whales will be established and monitored for 
the next 24 hours if four or more bowhead whale cow/calf pairs are 
observed at the surface during an aerial monitoring program within the 
area where an ensonified 120-dB zone around the vessel's track is 
projected. To the extent practicable, such

[[Page 27717]]

monitoring should focus on areas upstream (eastward) of the bowhead 
migration. No seismic surveying shall occur within the 120-dB safety 
zone around the area where these whale cow-calf pairs were observed, 
until two consecutive surveys (aerial or vessel) indicate they are no 
longer present within the 120-dB safety zone of seismic-surveying 
operations.
     A 160-dB vessel monitoring zone for bowhead and gray 
whales will be established and monitored in the Chukchi Sea and after 
August 25 in the Beaufort Sea during all seismic 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 nonmigratory, significant 
biological behavior (e.g., feeding, socializing)) are observed during 
an aerial or vessel monitoring program within the 160-dB safety zone 
around the seismic activity, the seismic operation will not commence or 
will shut down, until two consecutive surveys (aerial or vessel) 
indicate they are no longer present within the 160-dB safety zone of 
seismic-surveying operations.
     Survey information, especially information about bowhead 
whale cow-calf pairs or feeding bowhead or gray whales, shall be 
provided to NMFS as required in MMPA authorizations, and will form the 
basis for NMFS determining whether additional mitigation measures, if 
any, will be required over a given time period.
    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 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, where applicable, 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 Shell's IHA Application

    The monitoring plan proposed by Shell 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 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.
    Shell anticipates that there will be provision for crew rotation at 
least every six to eight weeks to avoid observer fatigue. During crew 
rotations detailed hand-over notes will be provided to the incoming 
crew leader by the outgoing leader. Other communications such as e-
mail, fax, and/or phone communication between the current and oncoming 
crew leaders during each rotation will also occur when possible. In the 
event of an unexpected crew change Shell will facilitate such 
communications to insure monitoring consistency among shifts.
    Crew leaders and most other biologists serving as observers in 2010 
will be individuals with experience as observers during one or more of 
the 1996-2009 seismic or shallow hazards monitoring projects in Alaska, 
the Canadian Beaufort, 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, familiar with the marine mammals of the 
area, and complete a NMFS approved observer training course designed to 
familiarize individuals with monitoring and data collection procedures. 
A marine mammal observers' handbook, adapted for the specifics of the 
planned survey program, will be prepared and distributed beforehand to 
all MMOs.
    Most observers, including Inupiat observers, will also complete a 
two-day training and refresher session on marine mammal monitoring, to 
be conducted shortly before the anticipated start of the 2010 open-
water season. Any exceptions will have or receive

[[Page 27718]]

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.
    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 and by MMS, or by other agreements in which Shell 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.
    MMOs will watch for marine mammals from the best available vantage 
point on the survey vessel, typically the bridge. MMOs will scan 
systematically with the unaided eye and 7 x 50 reticle binoculars, 
supplemented with 20 x 60 image-stabilized Zeiss Binoculars or Fujinon 
25 x 150 ``Big-eye'' binoculars and night-vision equipment when needed. 
Personnel on the bridge will assist the MMOs 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 of the MMO 
location.
    The ship's position, speed of support vessels, and water 
temperature, water depth, sea state, ice cover, visibility, and sun 
glare will also be recorded at the start and end of each observation 
watch, every 30 minutes during a watch, and whenever there is a change 
in any of those variables.
    Distances to nearby marine mammals will be estimated with 
binoculars (Fujinon 7 x 50 binoculars) containing a reticle to measure 
the vertical angle of the line of sight to the animal relative to the 
horizon. MMOs may use a laser rangefinder to test and improve their 
abilities for visually estimating distances to objects in the water. 
However, previous experience showed that a Class 1 eye-safe device was 
not able to measure distances to seals more than about 230 ft (70 m) 
away. The device was very useful in improving the distance estimation 
abilities of the observers at distances up to about 1968 ft (600 m)--
the maximum range at which the device could measure distances to highly 
reflective objects such as other vessels. Humans observing objects of 
more-or-less known size via a standard observation protocol, in this 
case from a standard height above water, quickly become able to 
estimate distances within about 20% when given immediate 
feedback about actual distances during training.
    For monitoring related to deployment of the AUV, MMOs will advise 
the vehicle operators prior to deployment if aggregations of marine 
mammals have been observed in the survey area which might increase the 
likelihood of the vehicle encountering an animal or otherwise 
disturbing a group of animals.
    Shell plans to conduct the site clearance and shallow hazards 
survey 24 hr/day. Regarding nighttime operations, note that there will 
be no periods of total darkness until mid-August. When operating under 
conditions of reduced visibility attributable to darkness or to adverse 
weather conditions, night-vision equipment (``Generation 3'' binocular 
image intensifiers, or equivalent units) will be available for use.
(2) Aerial Survey Program
    Shell proposes to conduct an aerial survey program in support of 
the shallow hazards program in the Beaufort Sea during the fall of 
2010. The shallow hazards survey program may start in the Beaufort Sea 
as early as July 2010, however, aerial surveys would not begin until 
the start of the bowhead whale migration, around August 20, 2010. The 
objectives of the aerial survey will be:
     To advise operating vessels as to the presence of marine 
mammals (primarily cetaceans) in the general area of operation;
     To collect and report data on the distribution, numbers, 
movement and behavior of marine mammals near the survey operations with 
special emphasis on migrating bowhead whales;
     To support regulatory reporting related to the estimation 
of impacts of survey operations on marine mammals;
     To investigate potential deflection of bowhead whales 
during migration by documenting how far east of survey operations a 
deflection may occur and where whales return to normal migration 
patterns west of the operations; and
     To monitor the accessibility of bowhead whales to Inupiat 
hunters.
    Specially-outfitted Twin Otter aircraft have an excellent safety 
record and are expected to be the survey aircraft. These aircraft will 
be specially modified for survey work and have been used extensively by 
NMFS, Alaska Department of Fish and Game, North Slope Borough, and LGL 
Limited during many marine mammal projects in Alaska, including 
industry funded projects as recent as the 2006-2008 seasons. The 
aircraft will be provided with a comprehensive set of survival 
equipment appropriate to offshore surveys in the Arctic. For safety 
reasons, the aircraft will be operated with two pilots.
    Aerial survey flights will begin around August 20, 2010. Surveys 
will then be flown daily during the shallow hazards survey operations, 
weather and flight conditions permitting, and continued for 5 to 7 days 
after all activities at the site have ended.
    The aerial survey procedures will be generally consistent with 
those used during earlier industry studies (Davis et al. 1985; Johnson 
et al. 1986; Evans et al. 1987; Miller et al. 1997, 1998, 1999, 2002; 
Patterson 2007). This will facilitate comparison and pooling of data 
where appropriate. However, the specific survey grids will be tailored 
to Shell's operations. During the 2010 open-water season Shell will 
coordinate and cooperate with the aerial surveys conducted by MMS/NMFS 
and any other groups conducting surveys in the same region.
    It is understood that shallow hazard survey timing and the specific 
location offshore of Harrison Bay are subject to change as a result of 
unpredictable weather and ice conditions. The aerial survey design is 
therefore intended to be flexible and able to adapt at short notice to 
changes in the operations.
    For marine mammal monitoring flights, aircraft will be flown at 
approximately 120 knots (138 mph) ground speed and usually at an 
altitude of 1,000 ft (305 m). Flying at a survey

[[Page 27719]]

speed of 120 knots (138 mph) greatly increases the amount of area that 
can be surveyed, given aircraft limitations, with minimal effect on the 
ability to detect bowhead whales. Surveys in the Beaufort Sea are 
directed at bowhead whales, and an altitude of 900-1,000 ft (274-305 m) 
is the lowest survey altitude that can normally be flown without 
concern about potential aircraft disturbance. Aerial surveys at an 
altitude of 1,000 ft (305 m) do not provide much information about 
seals but are suitable for both bowhead and beluga whales. The need for 
a 900-1000+ (274-305 m) ft cloud ceiling will limit the dates and times 
when surveys can be flown.
    Two primary observers will be seated at bubble windows on either 
side of the aircraft and a third observer will observe part time and 
record data the rest of the time. All observers need bubble windows to 
facilitate downward viewing. For each marine mammal sighting, the 
observer will dictate the species, number, size/age/sex class when 
determinable, activity, heading, swimming speed category (if 
traveling), sighting cue, ice conditions (type and percentage), and 
inclinometer reading to the marine mammal into a digital recorder. The 
inclinometer reading will be taken when the animal's location is 
90[deg] to the side of the aircraft track, allowing calculation of 
lateral distance from the aircraft trackline.
    Transect information, sighting data and environmental data will be 
entered into a GPS-linked computer by the third observer and 
simultaneously recorded on digital voice recorders for backup and 
validation. At the start of each transect, the observer recording data 
will record the transect start time and position, ceiling height (ft), 
cloud cover (in 10ths), wind speed (knots), wind direction ([deg]T) and 
outside air temperature ([deg]C). In addition, each observer will 
record the time, visibility (subjectively classified as excellent, 
good, moderately impaired, seriously impaired or impossible), sea state 
(Beaufort wind force), ice cover (in 10ths) and sun glare (none, 
moderate, severe) at the start and end of each transect, and at 2-min 
intervals along the transect. This will provide data in units suitable 
for statistical summaries and analyses of effects of these variables 
(and position relative to the survey vessel) on the probability of 
detecting animals (see Davis et al. 1982; Miller et al. 1999; Thomas et 
al. 2002). The data logger will automatically record time and aircraft 
position (latitude and longitude) for sightings and transect waypoints, 
and at pre-selected intervals along transects.
    Ice observations during aerial surveys will be recorded and 
satellite imagery may be used, where available, during post-season 
analysis to determine ice conditions adjacent to the survey area. These 
are standard practices for surveys of this type and are necessary in 
order to interpret factors responsible for variations in sighting 
rates.
    Shell will assemble the information needed to relate marine mammal 
observations to the locations of the survey vessel, and to the 
estimated received levels of industrial sounds at mammal locations. 
During the aerial surveys, Shell will record relevant information on 
other industry vessels, whaling vessels, low-flying aircraft, or any 
other human activities that are observed in the survey area.
    Shell will also consult with MMS/National Marine Mammal Laboratory 
regarding coordination during the survey activities and real-time 
sharing of data. The aims will be:
     To ensure aircraft separation when both crews conduct 
surveys in the same general region;
     to coordinate the 2010 aerial survey projects in order to 
maximize consistency and minimize duplication;
     To use data from MMS's broad-scale surveys to supplement 
the results of the more site specific Shell surveys for purposes of 
assessing the effects of shallow hazard survey activities on whales and 
estimating ``take by harassment'';
     To maximize consistency with previous years' efforts 
insofar as feasible.
    It is expected that raw bowhead sighting and flight-line data will 
be exchanged between MMS and Shell on a daily basis during the survey 
period, and that each team will also submit its sighting information to 
NMFS in Anchorage each day. After the Shell and MMS data files have 
been reviewed and finalized, they will be exchanged in digital form.
    Shell is not aware of any other related aerial survey programs 
presently scheduled to occur in the Alaskan Beaufort Sea in areas where 
Shell is anticipated to be conducting survey operations during July-
October 2010. However, one or more other programs are possible in 
support of other industry and research operations. If another aerial 
survey project were planned, Shell would seek to coordinate with that 
project to ensure aircraft separation, maximize consistency, minimize 
duplication, and share data.
    During the late summer and fall, bowhead whale is the primary 
species of concern, but belugas and gray whales are also present. To 
address concerns regarding deflection of bowheads at greater distances, 
the survey pattern around shallow hazards survey operations has been 
designed to document whale distribution from about 25 mi (40 km) east 
of Shell's vessel operations to about 37 mi (60 km) west of operations 
(see Figure 1 of Shell's 4MP).
    Bowhead whale movements during the late summer/autumn are generally 
from east to west, and transects should be designed to intercept rather 
than parallel whale movements. The transect lines in the grid will be 
oriented north-south, equally spaced at 5 mi (8 km) and randomly 
shifted in the east-west direction for each survey by no more than the 
transect spacing. The survey grid will total about 808 mi (1,300 km) in 
length, requiring approximately 6 hours to survey at a speed of 120 
knots (138 mph), plus ferry time. Exact lengths and durations will vary 
somewhat depending on the position of the survey operation and thus of 
the grid, the sequence in which lines are flown (often affected by 
weather), and the number of refueling/rest stops.
    Weather permitting, transects making up the grid in the Beaufort 
Sea will be flown in sequence from west to east. This decreases 
difficulties associated with double counting of whales that are 
(predominantly) migrating westward.
(3) Acoustic Monitoring
    As discussed earlier in this document, Shell will conduct SSV tests 
to establish the isopleths for the applicable safety radii. In 
addition, Shell proposes to use acoustic recorders to study bowhead 
deflections.
    Shell plans to deploy arrays of acoustic recorders in the Beaufort 
Sea in 2010, similar to that which was done in 2007 and 2008 using 
Directional Autonomous Seafloor Acoustic Recorders (DASARs) supplied by 
Greeneridge. These directional acoustic systems permit localization of 
bowhead whale and other marine mammal vocalizations. The purpose of the 
array will be to further understand, define, and document sound 
characteristics and propagation resulting from shallow hazards surveys 
that may have the potential to cause deflections of bowhead whales from 
their migratory pathway. Of particular interest will be the east-west 
extent of deflection, if any (i.e., how far east of a sound source do 
bowheads begin to deflect and how far to the west beyond the sound 
source does deflection persist). Of additional interest will be the 
extent of offshore (or towards shore) deflection that might occur.

[[Page 27720]]

    In previous work around seismic operations in the Alaskan Beaufort 
Sea, the primary method for studying this question has been aerial 
surveys. Acoustic localization methods will provide supplementary 
information for addressing the whale deflection question. Compared to 
aerial surveys, acoustic methods have the advantage of providing a 
vastly larger number of whale detections, and can operate day or night, 
independent of visibility, and to some degree independent of ice 
conditions and sea state--all of which prevent or impair aerial 
surveys. However, acoustic methods depend on the animals to call, and 
to some extent, assume that calling rate is unaffected by exposure to 
industrial noise. Bowheads call frequently in fall, but there is some 
evidence that their calling rate may be reduced upon exposure to 
industrial sounds, complicating interpretation. The combined use of 
acoustic and aerial survey methods will provide a suite of information 
that should be useful in assessing the potential effects of survey 
operations on migrating bowhead whales.
    Using passive acoustics with directional autonomous recorders, the 
locations of calling whales will be observed for a 6- to 10-week 
continuous monitoring period at five coastal sites (subject to 
favorable ice and weather conditions).
    Shell plans to conduct the whale migration monitoring using the 
passive acoustics techniques developed and used successfully since 2001 
for monitoring the migration past Northstar production island northwest 
of Prudhoe Bay and from Kaktovik to Harrison Bay during the 2007-2009 
migrations. Those techniques involve using DASARs to measure the 
arrival angles of bowhead calls at known locations, then triangulating 
to locate the calling whale.
    In attempting to assess the responses of bowhead whales to the 
planned industrial operations, it will be essential to monitor whale 
locations at sites both near and far from industry activities. Shell 
plans to monitor at five sites along the Alaskan Beaufort coast as 
shown in Figure 3 of Shell's 4MP. The eastern-most site (5 in 
Figure 3 of the 4MP) will be just east of Kaktovik and the western-most 
site (1 in Figure 3 of the 4MP) will be in the vicinity of 
Harrison Bay. Site 2 will be located west of Prudhoe Bay. Sites 4 and 3 
will be west of Camden Bay. These five sites will provide information 
on possible migration deflection well in advance of whales encountering 
an industry operation and on ``recovery'' after passing such operations 
should a deflection occur.
    The proposed geometry of DASARs at each site is comprised of seven 
DASARs oriented in a north-south pattern resulting in five equilateral 
triangles with 4.3-mi (7-km) element spacing. DASARs will be installed 
at planned locations using a GPS. However, each DASAR's orientation 
once it settles on the bottom is unknown and must be determined to know 
how to reference the call angles measured to the whales. Also, the 
internal clocks used to sample the acoustic data typically drift 
slightly, but linearly, by an amount up to a few seconds after 6 weeks 
of autonomous operation. Knowing the time differences within a second 
or two between DASARs is essential for identifying identical whale 
calls received on two or more DASARs.
    Bowhead migration begins in late August with the whales moving 
westward from their feeding sites in the Canadian Beaufort Sea. It 
continues through September and well into October. Shell will attempt 
to install the 21 DASARs at three sites (3, 4 and 5) in early August. 
The remaining 14 DASARs will be installed at sites 1 and 2 in late 
August. Thus, Shell proposes monitoring for whale calls from before 
August 15 until sometime before October 15, 2010.
    At the end of the season, the fourth DASAR in each array will be 
refurbished, recalibrated, and redeployed to collect data through the 
winter. The other DASARs in the arrays will be recovered. The 
redeployed DASARs will be programmed to record 35 min every 3 hours 
with a disk capacity of 10 months at that recording rate. This should 
be ample space to allow over-wintering from approximately mid-October 
2010, through mid-July 2011.
    Additional details on methodology and data analysis for the three 
types of monitoring described here (i.e., vessel-based, aerial, and 
acoustic) can be found in the 4MP in Shell's application (see 
ADDRESSES).

Additional Monitoring Measures Proposed by NMFS

    In addition to the vessel and aerial surveys and acoustic 
monitoring described above, NMFS proposes that Shell conduct vessel-
based monitoring in the Chukchi Seas during the fall bowhead whale 
migration period to detect bowhead whale cow/calf pairs within the 120-
dB isopleths (modeled at approximately 456 m or 1,496 ft) for 
mitigation purposes (See Proposed Mitigation section above).

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 Shell's 
4MP for Proposed Open Water Marine Survey Program in the Beaufort and 
Chukchi Seas, Alaska, during 2010. The panel met and reviewed the 4MP 
in late March 2010, and provided comments to NMFS in late April 2010. 
NMFS will consider all recommendations made by the panel, incorporate 
appropriate changes into the monitoring requirements of the IHA (if 
issued) and publish the panel's findings and recommendations in the 
final IHA notice of issuance or denial document.

Reporting Measures

(1) SSV Report
    A report on the preliminary results of the acoustic verification 
measurements, including as a minimum the measured 190-, 180-, 160-, and 
120-dB re 1 [mu]Pa (rms) radii of the source vessel(s) and the support 
vessels, will be submitted within 120 hr after collection and analysis 
of those measurements at the start of the field season. This report 
will specify the distances of the safety zones that were adopted for 
the marine survey activities.
(2) Technical Reports
    The results of Shell's 2010 open water marine survey monitoring 
program (i.e., vessel-based, aerial, and acoustic), including estimates 
of ``take'' by harassment, will be presented in the ``90-day'' and 
Final Technical reports. Shell proposes that 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

[[Page 27721]]

sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), group sizes, and ice cover; (d) analyses 
of the effects of survey operations; (e) sighting rates of marine 
mammals during periods with and without airgun activities (and other 
variables that could affect detectability); (f) initial sighting 
distances versus airgun activity state; (g) closest point of approach 
versus airgun activity state; (h) observed behaviors and types of 
movements versus airgun activity state; (i) numbers of sightings/
individuals seen versus airgun activity state; (j) distribution around 
the survey vessel versus airgun activity state; and (k) estimates of 
take by harassment. This information will be reported for both the 
vessel-based and aerial monitoring.
    Analysis of all acoustic data will be prioritized to address the 
primary questions. The primary data analysis questions are to (a) 
Determine when, where, and what species of animals are acoustically 
detected on each DASAR, (b) analyze data as a whole to determine 
offshore bowhead distributions as a function of time, (c) quantify 
spatial and temporal variability in the ambient noise, and (d) measure 
received levels of airgun activities. The bowhead detection data will 
be used to develop spatial and temporal animal distributions. 
Statistical analyses will be used to test for changes in animal 
detections and distributions as a function of different variables 
(e.g., time of day, time of season, environmental conditions, ambient 
noise, vessel type, operation conditions).
    The initial technical report is due to NMFS within 90 days of the 
completion of Shell's Beaufort and Chukchi Seas open water marine 
survey programs. The ``90-day'' report will 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.
(3) Comprehensive Report
    In November, 2007, Shell (in coordination and cooperation with 
other Arctic seismic IHA holders) released a final, peer-reviewed 
edition of the 2006 Joint Monitoring Program in the Chukchi and 
Beaufort Seas, July-November 2006 (LGL 2007). This report is available 
on the NMFS Protected Resources Web site (see ADDRESSES). In March, 
2009, Shell released a final, peer-reviewed edition of the Joint 
Monitoring Program in the Chukchi and Beaufort Seas, Open Water 
Seasons, 2006-2007 (Ireland et al. 2009). This report is also available 
on the NMFS Protected Resources Web site (see ADDRESSES). A draft 
comprehensive report for 2008 (Funk et al. 2009) was provided to NMFS 
and those attending the Arctic Stakeholder Open-water Workshop in 
Anchorage, Alaska, on April 6-8, 2009. The 2008 report provides data 
and analyses from a number of industry monitoring and research studies 
carried out in the Chukchi and Beaufort Seas during the 2008 open-water 
season with comparison to data collected in 2006 and 2007. Reviewers 
plan to provide comments on the 2008 report to Shell shortly. Once 
Shell is able to incorporate reviewer comments, the final 2008 report 
will be made available to the public. The 2009 draft comprehensive 
report is due to NMFS by mid-April 2010. NMFS will make this report 
available to the public upon receipt.
    Following the 2010 shallow hazards surveys a comprehensive report 
describing the vessel-based, aerial, and acoustic monitoring programs 
will be prepared. The comprehensive report will describe the methods, 
results, conclusions and limitations of each of the individual data 
sets in detail. The report will also integrate (to the extent possible) 
the studies into a broad based assessment of industry activities, and 
other activities that occur in the Beaufort and/or Chukchi seas, and 
their impacts on marine mammals during 2010. The report will help to 
establish long-term data sets that can assist with the evaluation of 
changes in the Chukchi and Beaufort Seas ecosystems. The report will 
attempt to provide a regional synthesis of available data on industry 
activity in offshore areas of northern Alaska that may influence marine 
mammal density, distribution and behavior. The comprehensive report 
will be due to NMFS within 240 days of the date of issuance of the IHA 
(if issued).
(4) Notification of Injured or Dead Marine Mammals
    Shell will 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. Shell will 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 
Shell that is not in the vicinity of the proposed open water marine 
survey program, Shell will 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 take of marine mammals is associated with 
noise propagation from the seismic airgun(s) used in the site clearance 
and shallow hazards 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: Tolerance; masking of 
natural sounds; behavioral disturbance; non-auditory physical effects; 
and, at least in theory, temporary or permanent hearing impairment 
(Richardson et al. 1995). As discussed earlier in this document, the 
most common impact will likely be from behavioral disturbance, 
including avoidance of the ensonified area or changes in speed, 
direction, and/or diving profile of the animal. For reasons discussed 
previously in this document, hearing impairment (TTS and PTS) is highly 
unlikely to occur based on the fact that most of the equipment to be 
used during Shell's proposed open water marine survey programs does not 
have received levels high enough to elicit even mild TTS beyond a short 
distance. For instance, for the airgun sources, the 180- and 190-dB re 
1 [mu]Pa (rms) isopleths extend to 125 m and 35 m from the source, 
respectively. None of the other active acoustic sources is expected to 
have received levels above 180 dB re 1 [mu]Pa (rms) within the 
frequency bands of marine mammal hearing sensitivity (below 180 kHz) 
beyond a few meters from the source. Finally, based on the proposed 
mitigation and monitoring measures described earlier in this document, 
no injury or mortality of marine mammals is anticipated as a result of 
Shell's

[[Page 27722]]

proposed open water marine survey programs.
    For impulse sounds, such as those produced by airgun(s) used for in 
the site clearance and shallow hazards surveys, NMFS uses the 160 dB re 
1 [mu]Pa (rms) isopleth to indicate the onset of Level B harassment. 
Shell provided calculations for the 160-dB isopleths produced by these 
active acoustic sources and then used those isopleths to estimate takes 
by harassment. NMFS used these calculations to make the necessary MMPA 
preliminary findings. Shell provides a full description of the 
methodology used to estimate takes by harassment in its IHA application 
(see ADDRESSES), which is also provided in the following sections.
    Shell has requested an authorization to take individuals of 11 
marine mammal species by Level B harassment. These 11 marine mammal 
species are: Beluga whale (Delphinapterus leucas), narwhal (Monodon 
monoceros), harbor porpoise (Phocoena phocoena), bowhead whale (Balaena 
mysticetus), gray whale (Eschrichtius robustus), humpback whale 
(Megaptera novaeangliae), minke whale (Balaenoptera acutorostrata), 
bearded seal (Erignathus barbatus), ringed seal (Phoca hispida), 
spotted seal (P. largha), and ribbon seal (Histriophoca fasciata). 
However, NMFS believes that narwhals, minke whales, and ribbon seals 
are not likely to occur in the proposed survey area during the time of 
the proposed site clearance and shallow hazards surveys. Therefore, 
NMFS believes that only the other eight of the 11 marine mammal species 
would likely be taken by Level B behavioral harassment as a result of 
the proposed marine surveys.

Basis for Estimating ``Take by Harassment''

    As stated previously, it is current NMFS policy to estimate take by 
Level B harassment for impulse sounds as occurring when an animal is 
exposed to a received level of 160 dB re 1[mu]Pa (rms). However, not 
all animals react to sounds at this low level, and many will not show 
strong reactions (and in some cases any reaction) until sounds are much 
stronger. Southall et al. (2007) provides a severity scale for ranking 
observed behavioral responses of both free-ranging marine mammals and 
laboratory subjects to various types of anthropogenic sound (see Table 
4 in Southall et al. (2007)). Tables 7, 9, and 11 in Southall et al. 
(2007) outline the numbers of low-frequency cetaceans, mid-frequency 
cetaceans, and pinnipeds in water, respectively, reported as having 
behavioral responses to multi-pulses in 10-dB received level 
increments. These tables illustrate that the more severe reactions did 
not occur until sounds were much higher than 160 dB re 1[mu]Pa (rms).
    The proposed open water marine surveys would use low energy active 
acoustic sources, including a total volume of 40 cu-in airgun or airgun 
array. Other active acoustic sources used for ice gouging and strudel 
score all have relatively low source levels and/or high frequencies 
beyond marine mammal hearing range. Table 1 depicts the modeled and/or 
measured source levels, and radii for the 120, 160, 180, and 190 dB re 
1[mu]Pa (rms) from various sources (or equivalent) that are proposed to 
be used in the marine mammal surveys by Shell.

     Table 1--A List of Active Acoustic Sources Proposed To Be Used for the Shell's 2010 Open Water Marine Surveys in the Chukchi and Beaufort Seas
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                               Radii (m) at modeled received levels  (dB
                                                                                                    Modeled                 re 1 [micro]Pa)
              Survey types                  Active acoustic sources             Frequency            source  -------------------------------------------
                                                                                                     level       190        180        160        120
--------------------------------------------------------------------------------------------------------------------------------------------------------
Site Clearance & Shallow Hazards........  40 cu-in airgun............  ..........................        217         35        125      1,220     14,900
                                         ---------------------------------------------------------------------------------------------------------------
                                          Dual frequency side scan...  190 & 240 kHz.............        225    Not modeled/measured because frequency
                                                                                                                 outputs beyond marine mammal hearing
                                                                                                                                range.
                                         ---------------------------------------------------------------------------------------------------------------
                                          Single beam echo sound.....  high: 100-340 kHz, low: 24-   180-200  Not modeled/measured because frequency
                                                                        50 kHz.                               outputs beyond marine mammal hearing
                                                                                                              range.
                                         ---------------------------------------------------------------------------------------------------------------
                                          Shallow sub-bottom profiler  3.5 kHz (Alpha Helix).....      193.8          1          3         14        310
                                                                       3.5 kHz (Henry C.)........      167.2         NA         NA          3        980
                                                                       400 Hz....................      176.8         NA         NA          9      1,340
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ice Gouging Surveys.....................  Dual freq sub-bottom         (2-7 kHz & 8-23 kHz.......      184.6         NA          2          7        456
                                           profiler.
                                         ---------------------------------------------------------------------------------------------------------------
                                          Multibeam Echo Sounder.....  240 kHz...................  Not modeled/measured because frequency outputs beyond
                                                                                                   marine mammal hearing range.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Strudel Scour Survey....................  Multibeam Echo Sounder.....  240 kHz...................  Not modeled/measured because frequency outputs beyond
                                                                                                   marine mammal hearing range.
                                         ---------------------------------------------------------------------------------------------------------------
                                          Single Beam Bathymetric      >200 kHz..................        215  Not modeled/measured because frequency
                                           Sonar.                                                             outputs beyond marine mammal hearing
                                                                                                              range.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    ``Take by Harassment'' is calculated in this section and Shell's 
application by multiplying the expected densities of marine mammals 
that may occur in the site clearance and shallow hazards survey area of 
water likely to be exposed to airgun impulses with received levels of 
>=160 dB re 1 [mu]Pa (rms). The single exception to this method is for 
the

[[Page 27723]]

estimation of exposures of bowhead whales during the fall migration 
where more detailed data were available allowing an alternate approach, 
described below, to be used. This section describes the estimated 
densities of marine mammals that may occur in the project area. The 
area of water that may be ensonified to the above sound levels is 
described further in the ``Potential Number of Takes by Harassment'' 
subsection.
    Marine mammal densities near the operation are likely to vary by 
season and habitat. However, sufficient published data allowing the 
estimation of separate densities during summer (July and August) and 
fall (September and October) are only available for beluga and bowhead 
whales. As noted above, exposures of bowhead whales during the fall are 
not calculated using densities (see below). Therefore, summer and fall 
densities have been estimated for beluga whales, and a summer density 
has been estimated for bowhead whales. Densities of all other species 
have been estimated to represent the duration of both seasons. The 
estimated 30 days of site clearance and shallow hazards survey activity 
will take place in eastern Harrison Bay at approximately five potential 
prospective future drill sites. The survey lines form a grid or survey 
``patch.'' It is expected that three of these patches will be surveyed 
during the summer and two during the fall. The areas of water exposed 
to sounds during surveys at the patches are separated by season in this 
manner and as described further below.
    Marine mammal densities are also likely to vary by habitat type. In 
the Alaskan Beaufort Sea, where the continental shelf break is 
relatively close to shore, marine mammal habitat is often defined by 
water depth. Bowhead and beluga occurrence within nearshore (0-131 ft, 
0-40 m), outer continental shelf (131-656 ft, 40-200 m), slope (656-
6,562 ft, 200-2,000 m), basin (>6,562 ft, 2,000 m), or similarly 
defined habitats have been described previously (Moore et al. 2000; 
Richardson and Thomson 2002). The presence of most other species has 
generally only been described relative to the entire continental shelf 
zone (0-656 ft, 0-200 m) or beyond. Sounds produced by the site 
clearance and shallow hazards surveys are expected to drop below 160 dB 
within the nearshore zone (0-131 ft, 0-40 m, water depth). Sounds >=160 
dB are not expected to occur in waters >656 ft (200 m). Because airgun 
sounds at the indicated levels would not be introduced to the outer 
continental shelf, separate beluga and bowhead densities for the outer 
continental shelf have not been used in the calculations.
    In addition to water depth, densities of marine mammals are likely 
to vary with the presence or absence of sea ice (see later for 
descriptions by species). At times during either summer or fall, pack-
ice may be present in some of the area near Harrison Bay. However, 
because some of the survey equipment towed behind the vessel may be 
damaged by ice, site clearance and shallow hazards survey activities 
will generally avoid sea-ice. Therefore, Shell has assumed that only 
10% of the area exposed to sounds >=160 dB by the survey will be near 
ice margin habitat. Ice-margin densities of marine mammals in both 
seasons have therefore been multiplied by 10% of the area exposed to 
sounds by the airguns, while open-water (nearshore) densities have been 
multiplied by the remaining 90% of the area (see area calculations 
below).
    To provide some allowance for the uncertainties, Shell calculated 
both ``maximum estimates'' as well as ``average estimates'' of the 
numbers of marine mammals that could potentially be affected. For a few 
marine mammal species, several density estimates were available, and in 
those cases the mean and maximum estimates were determined from the 
survey data. In other cases, no applicable estimate (or perhaps a 
single estimate) was available, so correction factors were used to 
arrive at ``average'' and ``maximum'' estimates. These are described in 
detail in the following subsections. NMFS has determined that the 
average density data of marine mammal populations will be used to 
calculate estimated take numbers because these numbers are based on 
surveys and monitoring of marine mammals in the vicinity of the 
proposed project area. For several species whose average densities are 
too low to yield a take number due to extra-limital distribution in the 
vicinity of the proposed survey area, but whose chance occurrence has 
been documented in the past, such as gray and humpback whales and 
harbor porpoises, NMFS allotted a few numbers of these species to allow 
unexpected takes of these species.
    Detectability bias, quantified in part by f(0), is associated with 
diminishing sightability with increasing lateral distance from the 
trackline. Availability bias [g(0)] refers to the fact that there is 
<100% probability of sighting an animal that is present along the 
survey trackline. Some sources of densities used below included these 
correction factors in their reported densities. In other cases the best 
available correction factors were applied to reported results when they 
had not been included in the reported data (e.g. Moore et al. 2000b).
(1) Cetaceans
    As noted above, the densities of beluga and bowhead whales present 
in the Beaufort Sea are expected to vary by season and location. During 
the early and mid-summer, most belugas and bowheads are found in the 
Canadian Beaufort Sea and Amundsen Gulf or adjacent areas. Low numbers 
are found in the eastern Alaskan Beaufort Sea. Belugas begin to move 
across the Alaskan Beaufort Sea in August, and bowheads do so toward 
the end of August.
    Beluga Whales--Beluga density estimates were derived from data in 
Moore et al. (2000). During the summer, beluga whales are most likely 
to be encountered in offshore waters of the eastern Alaskan Beaufort 
Sea or areas with pack ice. The summer beluga whale nearshore density 
was based on 11,985 km (7,749 mi) of on-transect effort and 9 
associated sightings that occurred in water <=50 m (164 ft) in Moore et 
al. (2000; Table 2). A mean group size of 1.63, a f(0) value of 2.841, 
and a g(0) value of 0.58 from Harwood et al. (1996) were also used in 
the calculation. Moore et al. (2000) found that belugas were equally 
likely to occur in heavy ice conditions as open water or very light ice 
conditions in summer in the Beaufort Sea, so the same density was used 
for both nearshore and ice-margin estimates (Table 2). The fall beluga 
whale nearshore density was based on 72,711 km (45,190 mi) of on-
transect effort and 28 associated sightings that occurred in water <=50 
m (164 ft) reported in Moore et al. (2000). A mean group size of 2.9 
(CV=1.9), calculated from all Beaufort Sea fall beluga sightings in 
<=50 m (164 ft) of water present in the MMS Bowhead Whale Aerial Survey 
Program (BWASP) database, along with the same f(0) and g(0) values from 
Harwood et al. (1996) were also used in the calculation. Moore et al. 
(2000) found that during the fall in the Beaufort Sea belugas occurred 
in moderate to heavy ice at higher rates than in light ice, so ice-
margin densities were estimated to be twice the nearshore densities. 
Based on the CV of group size maximum estimates in both season and 
habitats were estimated as four times the average estimates. ``Takes by 
harassment'' of beluga whales during the fall in the Beaufort Sea were 
not calculated in the same manner as described for bowhead whales 
(below) because of the relatively lower expected densities of beluga 
whales in nearshore habitat near the site clearance and shallow hazards 
surveys and the lack of

[[Page 27724]]

detailed data on the likely timing and rate of migration through the 
area (Table 3).

   Table 2--Expected Summer (Jul-Aug) Densities of Beluga and Bowhead
Whales in the Alaskan Beaufort Sea. Densities Are Corrected for f(0) and
                               g(0) Biases
------------------------------------------------------------------------
                                                 Nearshore    Ice Margin
                                                  Average      Average
                    Species                       Density      Density
                                                (/  (/
                                                   km\2\)       km\2\)
------------------------------------------------------------------------
Beluga whale..................................       0.0030       0.0030
Bowhead whale.................................       0.0186       0.0186
------------------------------------------------------------------------


 Table 3--Expected Fall (Sep-Nov) Densities of Beluga and Bowhead Whales
 in the Alaskan Beaufort Sea. Densities Are Corrected for f(0) and g(0)
                                 Biases
------------------------------------------------------------------------
                                                 Nearshore    Ice Margin
                                                  Average      Average
                    Species                       Density      Density
                                                (/  (/
                                                   km\2\)       km\2\)
------------------------------------------------------------------------
Beluga whale..................................       0.0027       0.0054
Bowhead whale*................................          N/A          N/A
------------------------------------------------------------------------
*See text for description of how bowhead whales estimates were made.

    Bowhead Whales--Industry aerial surveys of the continental shelf 
near Camden Bay in 2008 recorded eastward migrating bowhead whales 
until July 12 (Lyons and Christie 2009). No bowhead sightings were 
recorded again, despite continued flights, until August 19. Aerial 
surveys by industry operators did not begin until late August of 2006 
and 2007, but in both years bowheads were also recorded in the region 
before the end of August (Christie et al. 2009). The late August 
sightings were likely of bowheads beginning their fall migration so the 
densities calculated from those surveys were not used to estimate 
summer densities in this region. The three surveys in July 2008, 
resulted in density estimates of 0.0099, 0.0717, and 0.0186 whales/
km\2\, respectively. The estimate of 0.0186 whales/km\2\ was used as 
the average nearshore density, and the estimate of 0.0717 whales/km\2\ 
was used as the maximum (Table 2). Sea ice was not present during these 
surveys. Moore et al. (2000) reported that bowhead whales in the 
Alaskan Beaufort Sea were distributed uniformly relative to sea ice, so 
the same nearshore densities were used for ice-margin habitat.
    During the fall most bowhead whales will be migrating west past the 
site clearance and shallow hazards surveys, so it is less accurate to 
assume that the number of individuals present in the area from one day 
to the next will be static. However, feeding, resting, and milling 
behaviors are not entirely uncommon at this time and location either. 
In order to incorporate the movement of whales past the planned 
operations, and because the necessary data are available, Shell has 
developed an alternate method of calculating the number of individuals 
exposed to sounds produced by the site clearance and shallow hazards 
surveys. The method is founded on estimates of the proportion of the 
population that would pass within the >=160 dB rms zones on a given day 
in the fall during survey activities.
    Approximately 10 days of site clearance and shallow hazards survey 
activity are likely to occur during the fall period when bowheads are 
migrating through the Beaufort Sea. If the bowhead population has 
continued to grow at an annual rate of 3.4%, the current population 
size would be approximately 14,247 individuals based on a 2001 
population of 10,545 (Zeh and Punt 2005). Based on data in Richardson 
and Thomson (2002, Appendix 9.1), the number of whales expected to pass 
each day was estimated as a proportion of the population. Minimum and 
maximum estimates of the number of whales passing each day were not 
available, so a single estimate based on the 10-day moving average 
presented by Richardson and Thomson (2002) was used. Richardson and 
Thomson (2002) also calculated the proportion of animals within water 
depth bins (<20 m, 20-40 m, 40-200 m, >200 m; or <65 ft, 65-131 ft, 
131-656 ft, >656 ft). Using this information the total number of whales 
expected to pass the site clearance and shallow hazards surveys each 
day was multiplied by the proportion of whales that would be in each 
depth category to estimate how many individuals would be within each 
depth bin on a given day. The proportion of each depth bin falling 
within the >=160 dB rms zone was then multiplied by the number of 
whales within the respective bins to estimate the total number of 
individuals that would be exposed on each day. This was repeated for a 
total of 10 days (September 15-19 and October 1-4) and the results were 
summed to estimate the total number of bowhead whales that might be 
exposed to >=160 dB rms during the migration period in the Beaufort 
Sea.
    Other Cetaceans--For other cetacean species that may be encountered 
in the Beaufort Sea, densities are likely to vary somewhat by season, 
but differences are not expected to be great enough to require 
estimation of separate densities for the two seasons. Harbor porpoises 
and gray whales are not expected to be present in large numbers in the 
Beaufort Sea during the fall but small numbers may be encountered 
during the summer. They are most likely to be present in nearshore 
waters (Table 4). Narwhals are not expected to be encountered during 
the site clearance and shallow hazards surveys. However, there is a 
chance that a few individuals may be present if ice is nearby. The 
first record of humpback whales in the Beaufort Sea was documented in 
2007 so their presence cannot be ruled out. Since these species occur 
so infrequently in the Beaufort Sea, little to no data are available 
for the calculation of densities. Minimal densities have therefore been 
assigned for calculation purposes and to allow for chance encounters 
(Table 4).

 Table 4--Expected Densities of Cetaceans (Excluding Beluga and Bowhead
              Whale) and Seals in the Alaskan Beaufort Sea
------------------------------------------------------------------------
                                                 Nearshore    Ice Margin
                                                  Average      Average
                    Species                       Density      Density
                                                (/  (/
                                                   km\2\)       km\2\)
------------------------------------------------------------------------
Narwhal.......................................       0.0000       0.0000
Harbor porpoise...............................       0.0001       0.0000
Gray whale....................................       0.0001       0.0000
Bearded seal..................................       0.0181       0.0128
Ribbon seal...................................       0.0001       0.0001
Ringed seal...................................       0.3547       0.2510
Spotted seal..................................       0.0037       0.0001
------------------------------------------------------------------------

(2) Pinnipeds
    Extensive surveys of ringed and bearded seals have been conducted 
in the Beaufort Sea, but most surveys have been conducted over the 
landfast ice, and few seal surveys have occurred in open-water or in 
the pack ice. Kingsley (1986) conducted ringed seal surveys of the 
offshore pack ice in the central and eastern Beaufort Sea during late 
spring (late June). These surveys provide the most relevant information 
on densities of ringed seals in the ice margin zone of the Beaufort 
Sea. The density estimate in Kingsley (1986) was used as the average 
density of ringed seals that may be encountered in the ice margin 
(Table 6-3 in Shell's application and Table 4 here). The average ringed 
seal density in the nearshore zone of the Alaskan Beaufort Sea was 
estimated from results of ship-based surveys at times without seismic 
operations reported by Moulton and Lawson (2002; Table 6-3 in Shell's 
application and Table 4 here).

[[Page 27725]]

    Densities of bearded seals were estimated by multiplying the ringed 
seal densities by 0.051 based on the proportion of bearded seals to 
ringed seals reported in Stirling et al. (1982; Table 6-3 in Shell's 
application and Table 4 here). Spotted seal densities in the nearshore 
zone were estimated by summing the ringed seal and bearded seal 
densities and multiplying the result by 0.015 based on the proportion 
of spotted seals to ringed plus bearded seals reported in Moulton and 
Lawson (2002; Table 6-3 in Shell's application and Table 4 here). 
Minimal values were assigned as densities in the ice-margin zones 
(Table 6-3 in Shell's application and Table 4 here).

Potential Number of Takes by Harassment

    Numbers of marine mammals that might be present and potentially 
disturbed are estimated below based on available data about mammal 
distribution and densities at different locations and times of the year 
as described previously. The planned site clearance and shallow hazards 
survey would take place in the Beaufort Sea over two different seasons. 
The estimates of marine mammal densities have therefore been separated 
both spatially and temporarily in an attempt to represent the 
distribution of animals expected to be encountered over the duration of 
the site clearance and shallow hazards survey.
    The number of individuals of each species potentially exposed to 
received levels >=160 dB re 1[mu]Pa (rms) within each season and 
habitat zone was estimated by multiplying
     The anticipated area to be ensonified to the specified 
level in each season and habitat zone to which that density applies, by
     The expected species density.
    The numbers of potential individuals exposed were then summed for 
each species across the two seasons and habitat zones. Some of the 
animals estimated to be exposed, particularly migrating bowhead whales, 
might show avoidance reactions before being exposed to >=160 dB re 1 
[mu]Pa (rms). Thus, these calculations actually estimate the number of 
individuals potentially exposed to >=160 dB that would occur if there 
were no avoidance of the area ensonified to that level.
    The area of water potentially exposed to received levels >=160 dB 
re 1[mu]Pa (rms) by airgun operations was calculated by buffering a 
typical site clearance and shallow hazards survey grid of lines by the 
estimated >160 dB distance from the airgun source, including turns 
between lines during which a single mitigation airgun will be active. 
Measurements of a 2 x 10 in\3\ airgun array used in 2007 were reported 
by Funk et al. (2008). These measurements were used to model both of 
the potential airgun arrays that may be used in 2010, a 4 x 10 in\3\ 
array or a 2 x 10 in\3\ + 1 x 20 in\3\ array. The modeling results 
showed that the 40 cubic inch source is likely to produce sound that 
propagates further than the alternative array, so those results were 
used. The modeled 160 dB re 1[mu]Pa (rms) distance from a 40 cubic inch 
source was 1,220 m (4,003 ft) from the source. Because this is a 
modeled estimate, but based on similar measurements at the same 
location, the estimated distance was only increased by a factor of 1.25 
instead of a typical 1.5 factor. This results in a 160 dB distance of 
1,525 m (5,003 ft) which was added to both sides of survey lines in a 
typical site clearance and shallow hazards survey grid. The resulting 
area that may be exposed to airgun sounds >=160 dB re 1[mu]Pa (rms) is 
81.6 km\2\. In most cases the use of a single mitigation gun during 
turns will not appreciably increase the total area exposed to sounds 
>=160 dB re 1[mu]Pa (rms), but analysis of a similar survey pattern 
from the Chukchi Sea (but using the Beaufort sound radii) suggested use 
of the mitigation gun may increase this area to 82.3 km\2\. As 
described above, three patches (246.9 km\2\) are likely to be surveyed 
during the summer leaving two (164.6 km\2\) for the fall. During both 
seasons, 90% of the area has been multiplied by nearshore (open-water) 
densities, and the remaining 10% by the ice-margin densities.
    For analysis of potential effects on migrating bowhead whales we 
calculated the maximum distance perpendicular to the migration path 
ensonified to >=160 dB re 1[mu]Pa (rms) by a typical survey patch as 
11.6 km (7.2 mi). This distance represents approximately 21% of the 56 
km (34.8 mi) between the barrier islands and the 40-m (131-ft) 
bathymetry line so it was assumed that 21% of the bowheads migrating 
within the nearshore zone (water depth 0-40 m, or 0-131 ft) may be 
exposed to sounds >=160 dB re 1[mu]Pa (rms) if they showed no avoidance 
of the site clearance and shallow hazards survey activities.
    Cetaceans--Cetacean species potentially exposed to airgun sounds 
with received levels >=160 dB re 1[mu]Pa (rms) would involve bowhead, 
gray, humpback, and beluga whales and harbor porpoises. Shell also 
included some maximum exposure estimates for narwhal and minke whale. 
However, as stated previously in this document, NMFS has determined 
that authorizing take of these two cetacean species is not warranted 
given the highly unlikely potential of these species to occur in the 
open water marine survey area. The average estimates of the number of 
individual bowhead whales exposed to received sound levels >=160 dB re 
1[mu]Pa (rms) is 381 and belugas is 1 individual. However, since beluga 
whales often form small groups, therefore, it's likely that the 
exposure to the animals would be based on groups instead of individual 
animals. Therefore, NMFS proposes to make an adjustment to increase the 
number of beluga whale takes to 5 individuals to reflect the aggregate 
nature of these animals.
    The estimates show that one endangered cetacean species (the 
bowhead whale) is expected to be exposed to sounds >=160 dB re 1[mu]Pa 
(rms) unless bowheads avoid the area around the site clearance and 
shallow hazards survey areas (Tables 4). Migrating bowheads are likely 
to do so to some extent, though many of the bowheads engaged in other 
activities, particularly feeding and socializing, probably will not.
    As discussed before, although no take estimates of gray and 
humpback whales and harbor porpoises can be calculated due to their low 
density and extralimital distribution in the vicinity of the site 
clearance and shallow hazards survey area, their occurrence has been 
documented in the past. Therefore, to allow for chance encounters of 
these species, NMFS proposes to include two individuals of each of 
these three species as having the potential to be exposed to an area 
with received levels >=160 dB re 1[mu]Pa (rms).
    Pinnipeds--The ringed seal is the most widespread and abundant 
pinniped in ice-covered arctic waters, and there appears to be a great 
deal of year-to-year variation in abundance and distribution of these 
marine mammals. Ringed seals account for a large number of marine 
mammals expected to be encountered during the site clearance and 
shallow hazard survey activities, and hence exposed to sounds with 
received levels >=160 dB re 1[mu]Pa (rms). The average estimate is that 
567 ringed seals might be exposed to sounds with received levels >=160 
dB re 1[mu]Pa (rms) from airgun impulses.
    Two additional seal species are expected to be encountered. Average 
estimates for bearded seal exposures to sound levels >=160 dB re 
1[mu]Pa (rms) is 7 individuals. For spotted seal the exposure estimates 
is 1 individual.
    Table 5 summarizes the number of potential takes by harassment of 
all species.

[[Page 27726]]



 Table 5--Summary of the Number of Potential Exposures of Marine Mammals
to Received Sound Levels in the Water of >=160 dB During Shell's Planned
   Site Clearance and Shallow Hazards Surveys Near Harrison Bay in the
                Beaufort Sea, Alaska, July-October, 2010
------------------------------------------------------------------------
                                                     Total number of
                                                    exposures to sound
                    Species                        levels >=160 dB re 1
                                                       [mu]Pa (rms)
------------------------------------------------------------------------
Beluga whale...................................                        5
Harbor porpoise................................                        2
Bowhead whale..................................                      381
Gray whale.....................................                        2
Humpback whale.................................                        2
Bearded seal...................................                        7
Ringed seal....................................                      142
Spotted seal...................................                        1
------------------------------------------------------------------------

Estimated Take Conclusions

    Cetaceans--Effects on cetaceans are generally expected to be 
restricted to avoidance of an area around the site clearance and 
shallow hazards surveys and short-term changes in behavior, falling 
within the MMPA definition of ``Level B harassment.''
    Using the 160 dB criterion, the average estimates of the numbers of 
individual cetaceans exposed to sounds >=160 dB re 1 [mu]Pa (rms) 
represent varying proportions of the populations of each species in the 
Beaufort Sea and adjacent waters. For species listed as ``Endangered'' 
under the ESA, the estimates include approximately 381 bowheads. This 
number is approximately 2.7% of the Bering-Chukchi-Beaufort population 
of >14,247 assuming 3.4% annual population growth from the 2001 
estimate of >10,545 animals (Zeh and Punt 2005). The small numbers of 
other mysticete whales that may occur in the Beaufort Sea are unlikely 
to occur near the planned site clearance and shallow hazards surveys. 
The few that might occur would represent a very small proportion of 
their respective populations. The average estimate of the number of 
belugas that might be exposed to >=160 dB re 1 [mu]Pa (rms) (1, with 
adjustment to 5 considering group occurrence) represents <1% of its 
population.
    Seals--A few seal species are likely to be encountered in the study 
area, but ringed seal is by far the most abundant in this area. The 
average estimates of the numbers of individuals exposed to sounds at 
received levels >=160 dB re 1 [mu]Pa (rms) during the site clearance 
and shallow hazards surveys are as follows: ringed seals (142), bearded 
seals (7), and spotted seals (1), (representing <1% of their respective 
Beaufort Sea populations).

Negligible Impact and Small Numbers Analysis and Preliminary 
Determination

    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``. . . 
an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the takes occur.
    No injuries or mortalities are anticipated to occur as a result of 
Shell's proposed 2010 open water marine surveys in the Beaufort and 
Chukchi Seas, 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 the survey areas.
    Some studies have shown that bowhead whales will continue to feed 
in areas of seismic operations (e.g., Richardson, 2004). Therefore, it 
is reasonable to conclude that the marine surveys using active acoustic 
sources will not displace bowhead whales from their important feeding 
areas. Also, it is important to note that the sounds produced by the 
proposed Shell marine surveys are of much lower intensity than those 
produced by airgun arrays during a 3D or 2D seismic survey. Should 
bowheads choose to feed in the ensonified area instead of avoiding the 
sound, individuals may be exposed to sounds at or above 160 dB re 1 
[mu]Pa (rms) when the survey vessel passes by. Depending on the 
direction and speed of the survey vessel, the duration of exposure is 
not expected to be more than 15 minutes (assuming the survey vessel is 
traveling at 4 knots (7.5 km/hr) and heading directly towards the whale 
but without engaging the whale inside the safety zone). While feeding 
in an area of increased anthropogenic sound even below NMFS current 
threshold for behavioral harassment for impulse sound, i.e. 160 dB re 1 
[mu]Pa (rms), may potentially result in increased stress, it is not 
anticipated that the low received levels from marine surveys and the 
amount of time that an individual whale may remain in the area to feed 
would result in extreme physiological stress to the animal (see review 
by Southall et al. 2007). Additionally, if an animal is excluded from 
the area (such as Harrison Bay) for feeding because it decides to avoid 
the ensonified area, this may result in some extra energy expenditure 
for the animal to find an alternate feeding area. However, there are 
multiple feeding areas nearby in the Beaufort Sea for bowhead whales to 
choose from. The disruption to feeding is not anticipated to have more 
than a negligible impact on the affected species or stock.
    Beluga whales are less likely to occur in the proposed marine 
survey area than bowhead whales in Beaufort Sea. Should any belugas 
occur in the area of marine surveys, it is not expected that they would 
be exposed for a prolonged period of time, for the same reason 
discussed above due to the movement of survey vessel and animals. Gray 
whales, humpback whales, and harbor porpoises rarely occur in the 
Beaufort Sea, therefore, the potential effects to these species from 
the proposed open water marine surveys is expected to be close to none. 
The exposure of cetaceans to sounds produced by the proposed marine 
surveys is not expected to result in more than Level B harassment and 
is anticipated to have no more than a negligible impact on the affected 
species or stock.
    Some individual pinnipeds may be exposed to sound from the proposed 
marine surveys more than once during the time frame of the project. 
However, as discussed previously, due to the constant moving of the 
survey vessel, the probability of an individual pinniped being exposed 
to multiple times is much lower than if the source is stationary. 
Therefore, NMFS has preliminarily determined that the exposure of 
pinnipeds to sounds produced by the proposed marine surveys in the 
Beaufort and Chukchi Seas is not expected to result in more than Level 
B harassment and is anticipated to have no more than a negligible 
impact on the animals.
    Of the eight marine mammal species likely to occur in the proposed 
marine survey area, only the bowhead and humpback whales are listed as 
endangered under the ESA. The species are also designated as 
``depleted'' under the MMPA. Despite these designations, the Bering-
Chukchi-Beaufort stock of bowheads has been increasing at a rate

[[Page 27727]]

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 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 whale and humpback whale. The 
bearded and ringed seals are ``candidate species'' under the ESA, 
meaning they are currently being considered for listing but are not 
designated as depleted under the MMPA. None of the other three 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 0.01% of 
the Beaufort Sea population of approximately 39,258 beluga whales 
(Allen and Angliss 2010), 0.004% of Bering Sea stock of approximately 
48,215 harbor porpoises, 0.01% of the Eastern North Pacific stock of 
approximately 17,752 gray whales, 2.67% of the Bering-Chukchi-Beaufort 
population of 14,247 individuals assuming 3.4 percent annual population 
growth from the 2001 estimate of 10,545 animals (Zeh and Punt, 2005), 
and 0.21% of the Western North Pacific stock of approximately 938 
humpback whales. The take estimates presented for bearded, ringed, and 
spotted seals represent 0.003, 0.06, and 0.002 percent of U.S. Arctic 
stocks of each species, respectively. These estimates represent the 
percentage of each species or stock that could be taken by Level B 
behavioral harassment if each animal is taken only once. In addition, 
the mitigation and monitoring measures (described previously in this 
document) proposed for inclusion in the IHA (if issued) are expected to 
reduce even further any potential disturbance to marine mammals.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the mitigation and monitoring 
measures, NMFS preliminarily finds that Shell's proposed 2010 open 
water marine surveys in the Beaufort and Chukchi Seas may result in the 
incidental take of small numbers of marine mammals, by Level B 
harassment only, and that the total taking from the marine surveys will 
have a negligible impact on the affected species or stocks.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

Relevant Subsistence Uses

    The disturbance and potential displacement of marine mammals by 
sounds from the proposed marine surveys are the principal concerns 
related to subsistence use of the area. Subsistence remains the basis 
for Alaska Native culture and community. Marine mammals are legally 
hunted in Alaskan waters by coastal Alaska Natives. In rural Alaska, 
subsistence activities are often central to many aspects of human 
existence, including patterns of family life, artistic expression, and 
community religious and celebratory activities. Additionally, the 
animals taken for subsistence provide a significant portion of the food 
that will last the community throughout the year. The main species that 
are hunted include bowhead and beluga whales, ringed, spotted, and 
bearded seals, walruses, and polar bears. (As mentioned previously in 
this document, both the walrus and the polar bear are under the USFWS' 
jurisdiction.) The importance of each of these species varies among the 
communities and is largely based on availability.
    The subsistence communities in the Beaufort and Chukchi Seas that 
have the potential to be impacted by Shell's proposed open water marine 
surveys include Kaktovik, Nuiqsut, Barrow, Wainwright, and Point Lay. 
Kaktovik is a coastal community near the east boundary of the proposed 
ice gouging area. Nuiqsut is approximately 30 mi (50 km) inland from 
the proposed site clearance and shallow hazards survey area. Cross 
Island, from which Nuiqsut hunters base their bowhead whaling 
activities, is approximately 44 mi (70 km) east of the proposed site 
clearance and shallow hazards survey area. Barrow lies approximately 
168 mi (270 km) west of Shell's Harrison Bay site clearance and shallow 
hazards survey areas. Wainwright is a coastal community approximately 
12 mi (20 km) to the southeast boundary of the proposed ice gouging 
survey area in the Chukchi Sea. Point Lay is another coastal community 
boarding the southwest boundary of the proposed ice gouging survey area 
in the Chukchi Sea. Point Hope is the western tip of the North Slope 
and is approximately 124 mi (200 km) southwest of Shell's proposed ice 
gouge survey area in the Chukchi Sea.
(1) Bowhead Whales
    Of the three communities along the Beaufort Sea coast, Barrow is 
the only one that currently participates in a spring bowhead whale 
hunt. However, this hunt is not anticipated to be affected by Shell's 
activities, as the spring hunt occurs in late April to early May, and 
Shell's marine surveys in Beaufort Sea will not begin until July at the 
earliest.
    All three communities participate in a fall bowhead hunt. In 
autumn, westward-migrating bowhead whales typically reach the Kaktovik 
and Cross Island (Nuiqsut hunters) areas by early September, at which 
point the hunts begin (Kaleak 1996; Long 1996; Galginaitis and Koski 
2002; Galginaitis and Funk 2004, 2005; Koski et al. 2005). Around late 
August, the hunters from Nuiqsut establish camps on Cross Island from 
where they undertake the fall bowhead whale hunt. The hunting period 
starts normally in early September and may last as late as mid-October, 
depending mainly on ice and weather conditions and the success of the 
hunt. Most of the hunt occurs offshore in waters east, north, and 
northwest of Cross Island where bowheads migrate and not inside the 
barrier islands (Galginaitis 2007). Hunters prefer to take bowheads 
close to shore to avoid a long tow, but Braund and Moorehead (1995) 
report that crews may (rarely) pursue whales as far as 50 mi (80 km) 
offshore. Whaling crews use Kaktovik as their home base, leaving the 
village and returning on a daily basis. The core whaling area is within 
12 mi (19.3 km) of the village with a periphery ranging about 8 mi (13 
km) farther, if necessary. The extreme limits of the Kaktovik whaling 
hunt would be the middle of Camden Bay to the west. The timing of the 
Kaktovik bowhead whale hunt roughly parallels the Cross Island whale 
hunt (Impact Assessment Inc 1990b; SRB&A 2009: Map 64). In recent 
years, the hunts at Kaktovik and Cross Island have usually ended by 
mid- to late September.

[[Page 27728]]

    Westbound bowheads typically reach the Barrow area in mid-
September, and are in that area until late October (Brower 1996). 
However, over the years, local residents report having seen a small 
number of bowhead whales feeding off Barrow or in the pack ice off 
Barrow during the summer. Recently, autumn bowhead whaling near Barrow 
has normally begun in mid-September to early October, but in earlier 
years it began as early as August if whales were observed and ice 
conditions were favorable (USDI/BLM 2005). The recent decision to delay 
harvesting whales until mid-to-late September has been made to prevent 
spoilage, which might occur if whales were harvested earlier in the 
season when the temperatures tend to be warmer. Whaling near Barrow can 
continue into October, depending on the quota and conditions.
    Along the Chukchi Sea, the spring bowhead whale hunt for Wainwright 
occurs between April and June in leads offshore from the village. 
Whaling camps can be located up to 16-24 km (10-15 mi) from shore, 
depending on where the leads open up. Whalers prefer to be closer, 
however, and will sometimes go overland north of Wainwright to find 
closer leads (SRBA 1993). Residents of Point Lay have not hunted 
bowhead whales in the recent past, but were selected by the 
International Whaling Commission (IWC) to receive a bowhead whale quota 
in 2009, and began bowhead hunting again in 2009. In the more distant 
past, Point Lay hunters traveled to Barrow, Wainwright, or Point Hope 
to participate in the bowhead whale harvest activities. In Point Hope, 
the bowhead whale hunt occurs between March and June, when the pack-ice 
lead is usually 10-11 km (6-7 mi) offshore. Camps are set up along the 
landfast ice edge to the south and southeast of the village. Point Hope 
whalers took between one and seven bowhead whales per year between 1978 
and 2008, with the exception of 1980, 1989, 2002, and 2006, when no 
whales were taken (Suydam and George 2004; Suydam et al. 2008, 2007, 
2006, 2005). There is no fall bowhead hunt in Point Hope, as the whales 
migrate back down on the west side of the Bering Strait, out of range 
of the Point Hope whalers (Fuller and George 1997).
(2) Beluga Whales
    Beluga whales are not a prevailing subsistence resource in the 
communities of Kaktovik and Nuiqsut. Kaktovik hunters may harvest one 
beluga whale in conjunction with the bowhead hunt; however, it appears 
that most households obtain beluga through exchanges with other 
communities. Although Nuiqsut hunters have not hunted belugas for many 
years while on Cross Island for the fall hunt, this does not mean that 
they may not return to this practice in the future. Data presented by 
Braund and Kruse (2009) indicate that only one percent of Barrow's 
total harvest between 1962 and 1982 was of beluga whales and that it 
did not account for any of the harvested animals between 1987 and 1989.
    There has been minimal harvest of beluga whales in Beaufort Sea 
villages in recent years. Additionally, if belugas are harvested, it is 
usually in conjunction with the fall bowhead harvest. Shell will not be 
operating during the Kaktovik and Nuiqsut fall bowhead harvests.
    In the Chukchi communities, the spring beluga hunt by Wainwright 
residents is concurrent with the bowhead hunt, but belugas are 
typically taken only during the spring hunt if bowheads are not present 
in the area. Belugas are also hunted later in the summer, between July 
and August, along the coastal lagoon systems. Belugas are usually taken 
less than 16 km (10 mi) from shore. Beluga whales are harvested in June 
and July by Point Lay residents. They are taken in the highest numbers 
in Naokak and Kukpowruk Passes south of Point Lay, but hunters will 
travel north to Utukok Pass and south to Cape Beaufort in search of 
belugas. The whales are usually herded by hunters with their boats into 
the shallow waters of Kasegaluk Lagoon (MMS 2007). In Point Hope, 
belugas are also hunted in the spring, coincident with the spring 
bowhead hunt. A second hunt takes place later in the summer, in July 
and August, and can extend into September, depending on conditions and 
the IWC quota. The summer hunt is conducted in open water along the 
coastline on either side of Point Hope, as far north as Cape Dyer (MMS 
2007). Belugas are smaller than bowhead whales, but beluga whales often 
make up a significant portion of the total harvest for Point Hope 
(Fuller and George 1997; SRBA 1993). Ninety-eight belugas harvested in 
1992 made up 40.3% of the total edible harvest for that year. Three 
bowhead whales represented 6.9% of the total edible harvest for the 
same year (Fuller and George 1997).
(3) Ice Seals
    Ringed seals are available to subsistence users in the Beaufort Sea 
year-round, but they are primarily hunted in the winter or spring due 
to the rich availability of other mammals in the summer. Bearded seals 
are primarily hunted during July in the Beaufort Sea; however, in 2007, 
bearded seals were harvested in the months of August and September at 
the mouth of the Colville River Delta. An annual bearded seal harvest 
occurs in the vicinity of Thetis Island in July through August. 
Approximately 20 bearded seals are harvested annually through this 
hunt. Spotted seals are harvested by some of the villages in the summer 
months. Nuiqsut hunters typically hunt spotted seals in the nearshore 
waters off the Colville River delta, which drains into Harrison Bay, 
where Shell's proposed site clearance and shallow hazards surveys are 
planned.
    Although there is the potential for some of the Beaufort villages 
to hunt ice seals during the summer and fall months while Shell is 
conducting marine surveys, the primary sealing months occur outside of 
Shell's operating time frame.
    In the Chukchi Sea, seals are most often taken between May and 
September by Wainwright residents. Wainwright hunters will travel as 
far south as Kuchaurak Creek (south of Point Lay) and north to Peard 
Bay. Hunters typically stay within 72 km (45 mi) of the shore. Ringed 
and bearded seals are harvested all year by Point Lay hunters. Ringed 
seals are hunted 32 km (20 mi) north of Point Lay, as far as 40 km (25 
mi) offshore. Hunters travel up to 48 m (30 mi) north of the community 
for bearded seals, which are concentrated in the Solivik Island area. 
Bearded seals are also taken south of the community in Kasegaluk 
Lagoon, and as far as 40 km (25 mi) from shore. Seals are harvested 
throughout most of the year by the Point Hope community, although they 
tend to be taken in the greatest numbers in the winter and spring 
months. The exception is the bearded seal hunt, which peaks later in 
the spring and into the summer (Fuller and George 1997; MMS 2007). 
Species of seals harvested by Point Hope hunters include ringed, 
spotted, and bearded. Seals are hunted on the ice (Fuller and George 
1997). Hunters tend to stay close to the shore but will travel up to 24 
km (15 mi) offshore south of the point, weather dependent. Seals are 
hunted to the north of the community as well, but less often, as the 
ice is less stable and can be dangerous. Seals are taken between 
Akoviknak Lagoon to the south and Ayugatak Lagoon to the north (MMS 
2007).

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

[[Page 27729]]

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.

    Noise and general activity during Shell's proposed open water 
marine surveys have the potential to impact marine mammals hunted by 
Native Alaskans. In the case of cetaceans, the most common reaction to 
anthropogenic sounds (as noted previously in this document) is 
avoidance of the ensonified area. In the case of bowhead whales, this 
often means that the animals divert from their normal migratory path by 
several kilometers. Additionally, general vessel presence in the 
vicinity of traditional hunting areas could negatively impact a hunt.
    In the case of subsistence hunts for bowhead whales in the Beaufort 
and Chukchi Seas, there could be an adverse impact on the hunt if the 
whales were deflected seaward (further from shore) in traditional 
hunting areas. The impact would be that whaling crews would have to 
travel greater distances to intercept westward migrating whales, 
thereby creating a safety hazard for whaling crews and/or limiting 
chances of successfully striking and landing bowheads.

Plan of Cooperation (POC or Plan)

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a 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.
    Shell is preparing to implement a POC pursuant to MMS Lease Sale 
Stipulation No. 5, which requires that all exploration operations be 
conducted in a manner that prevents unreasonable conflicts between oil 
and gas activities and the subsistence activities and resources of 
residents of the North Slope.
    The POC will identify the measures that Shell has developed in 
consultation with North Slope subsistence communities and will 
implement during its planned 2010 site clearance and shallow hazards 
surveys and ice gouge surveys to minimize any adverse effects on the 
availability of marine mammals for subsistence uses. In addition, the 
POC will detail Shell's communications and consultations with local 
subsistence communities concerning its planned 2010 program, potential 
conflicts with subsistence activities, and means of resolving any such 
conflicts. Shell continues to document its contacts with the North 
Slope subsistence communities, as well as the substance of its 
communications with subsistence stakeholder groups.
    Shell states that the POC will be, and has been in the past, the 
result of numerous meetings and consultations between Shell, affected 
subsistence communities and stakeholders, and federal agencies. The POC 
identifies and documents potential conflicts and associated measures 
that will be taken to minimize any adverse effects on the availability 
of marine mammals for subsistence use. Outcomes of POC meetings are 
typically included in updates attached to the POC as addenda and 
distributed to federal, state, and local agencies as well as local 
stakeholder groups that either adjudicate or influence mitigation 
approaches for Shell's open water programs.
    Meetings for Shell's 2010 program in the Beaufort and Chukchi Seas 
are planned for Nuiqsut, Kaktovik, Barrow, Point Hope, Point Lay, 
Wainwright, and Kotzebue in the 1st quarter of 2010. Shell met with the 
marine mammal commissions and committees including the Alaska Eskimo 
Whaling Commission (AEWC), Eskimo Walrus Commission (EWC), Alaska 
Beluga Whale Committee (ABWC), Alaska Ice Seal Committee (AISC), and 
the Alaska Nanuuq Commission (ANC) on December 8, 2009 in co-management 
meeting. Throughout 2010 Shell anticipates continued engagement with 
the marine mammal commissions and committees active in the subsistence 
harvests and marine mammal research.
    Following the 2010 season, Shell intends to have a post-season co-
management meeting with the commissioners and committee heads to 
discuss results of mitigation measures and outcomes of the preceding 
season. The goal of the post-season meeting is to build upon the 
knowledge base, discuss successful or unsuccessful outcomes of 
mitigation measures, and possibly refine plans or mitigation measures 
if necessary.

Subsistence Mitigation Measures

    Shell plans to introduce the following mitigation measures, plans 
and programs to potentially affected subsistence groups and 
communities. These measures, plans, and programs have been effective in 
past seasons of work in the Arctic and were developed in past 
consultations with these communities. These measures, plans, and 
programs will be implemented by Shell during its 2010 program in both 
the Beaufort and Chukchi Seas to monitor and mitigate potential impacts 
to subsistence users and resources. The mitigation measures Shell has 
adopted and will implement during 2010 are listed and discussed below.
    Shell states that it will implement the following additional 
measures to ensure coordination of its activities with local 
subsistence users to minimize further the risk of impacting marine 
mammals and interfering with any subsistence hunts:
     To minimize impacts on marine mammals and subsistence 
hunting activities, the source vessel will transit through the Chukchi 
Sea along a route that lies offshore of the polynya zone. This entry 
into the Chukchi Sea will not occur before July 1, 2010. In the event 
the transit outside of the polynya zone results in Shell having to move 
away from ice, the source vessel may enter into the polynya zone. If it 
is necessary to move into the polynya zone, Shell will notify the local 
communities of the change in the transit route through the Com Centers.
     Shell has developed a Communication Plan and will 
implement the plan before initiating the 2010 program to coordinate 
activities with local subsistence users as well as Village Whaling 
Associations in order to minimize the risk of interfering with 
subsistence hunting activities, and keep current as to the timing and 
status of the bowhead whale migration, as well as the timing and status 
of other subsistence hunts. The Communication Plan includes procedures 
for coordination with Communication and Call Centers to be located in 
coastal villages along the Beaufort and Chukchi Seas during Shell's 
program in 2010.
     Shell will employ local Subsistence Advisors from the 
Beaufort and Chukchi Sea villages to provide consultation and guidance 
regarding the whale migration and subsistence hunt. There may be up 
nine subsistence advisor-liaison positions (one per village), to work 
approximately 8-hours per day and 40-hour weeks through Shell's 2010 
program. The subsistence advisor will use local knowledge (Traditional 
Knowledge) to gather data on subsistence lifestyle within the community 
and advise as to ways to minimize and mitigate potential impacts to 
subsistence resources during program activities. Responsibilities 
include reporting any subsistence concerns or conflicts; coordinating 
with subsistence users; reporting subsistence-related comments, 
concerns, and information;

[[Page 27730]]

and advising how to avoid subsistence conflicts. A subsistence advisor 
handbook will be developed prior to the operational season to specify 
position work tasks in more detail.
     Shell will also implement flight restrictions prohibiting 
aircraft from flying within 1,000 ft (300 m) of marine mammals or below 
1,500 ft (457 m) altitude (except during takeoffs and landings or in 
emergency situations) while over land or sea.

Unmitigable Adverse Impact Analysis and Preliminary Determination

    NMFS has preliminarily determined that Shell's proposed 2010 open 
water marine surveys in the Beaufort and Chukchi Seas 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 Shell's POC. 
Shell has adopted a spatial and temporal strategy for its Arctic open 
water marine surveys that should minimize impacts to subsistence 
hunters, which is discussed in detail below, broken into different 
subsistence activities.
(1) Bowhead Whales
    During the proposed period of activity (July through October) most 
marine mammals are expected to be dispersed throughout the area, except 
during the peak of the bowhead whale migration in the Beaufort Sea, 
which occurs from late August into October. Bowhead whales are expected 
to be in the Canadian Beaufort Sea during much of the time prior to 
subsistence whaling and, therefore, are not expected to be affected by 
the site clearance and shallow hazard surveys prior to then. Further, 
site clearance and shallow hazards surveys will be conducted over 50-
100 mi (80-160 km) west of the furthest west boundary of the 
traditional bowhead hunting waters used by Kaktovik hunters, 10-50 mi 
(16-80 km) west of Cross Island from where Nuiqsut hunters base their 
harvest, and over 35 miles east of the furthest east boundary of the 
traditional bowhead hunting waters used by Barrow hunters. In light of 
the small sound source for these surveys and resulting ensonified area 
> 160 dB (1,525 m) described previously in this document, the sheer 
distances from where these site clearance and shallow hazard surveys 
will occur from the areas of Kaktovik and Barrow bowhead hunts serve to 
mitigate any prospect of impact to the hunts. Site clearance and 
shallow hazard surveys will be timed to occur beyond the traditional 
boundary of Nuiqsut hunts, besides occurring 10-50 mi (16-80 km) west 
of Cross Island and ``downstream'' of this bowhead whale hunt, thereby 
mitigating the prospect of impact to Nuiqsut whaling. In addition, 
Shell will execute a communication plan and use communication and call 
centers located in coastal villages of the Beaufort Sea (see above) to 
communicate activities and routine vessel traffic with subsistence 
users throughout the period in which all surveys will be conducted. As 
a result of the distance and spatial location of site clearance and 
shallow hazard surveys from traditional bowhead whale subsistence 
harvest, any effects on the bowhead whale, as a subsistence resource, 
will be negligible.
    Activities associated with Shell's planned ice gouge surveys in 
Camden Bay would have no or negligible effect on the availability of 
bowhead whales for the Kaktovik, Nuiqsut, and Barrow subsistence 
whaling harvests. Mitigation of the impact from ice gouge surveys 
includes the possible use of either an AUV, or conventional survey 
method without airguns, and timing and location of surveys. The AUV 
will be launched from the stern of a vessel and will survey the 
seafloor close to the vessel. The vessel will transit an area, with the 
AUV surveying the area behind the vessel. Marine mammal observers 
onboard the vessel ensures the AUV has a minimal impact on the 
environment. The AUV also has a Collision Avoidance System and operates 
without a towline that reduces potential impact to marine mammals. 
Using bathymetric sonar or multi-beam echo sounder the AUV can record 
the gouges on the seafloor surface caused by ice keels. The Sub-bottom 
profiler can record layers beneath the surface to about 20 ft (6.1 m). 
The AUV is more maneuverable and able to complete surveys quicker than 
a conventional survey. This reduces the duration that vessels producing 
sound must operate. Also, the ice gouge surveys will be timed to avoid 
locations east of Mary Sachs Entrance in Camden Bay during the bowhead 
subsistence harvest of Kaktovik. The ice gouge survey locations through 
Mary Sachs Entrance and out into Camden Bay are more than 40 mi (64 km) 
east of Cross Island, and given this distance plus the low-level sound 
source of the ice gouge surveys, this will mitigate impact to the 
Nuiqsut bowhead whale subsistence harvest. Timing of activities will be 
coordinated via the nearest communication and call centers operating in 
the Beaufort Sea, presumably in Kaktovik and Deadhorse. As a result of 
the timing, location, and lack of an airgun source for the ice gouge 
surveys, any effects on the bowhead whale, as a subsistence resource, 
will be negligible.
    Ice gouge survey activities in the Chukchi Sea will be scheduled to 
avoid impact to bowhead whale subsistence harvests that could be 
conducted in the Chukchi Sea communities of Wainwright or Point Hope. 
Scheduling will be coordinated via the nearest communication and call 
center operating in the Chukchi Sea communities.
(2) Beluga Whales
    Beluga are not a prevailing subsistence resource in the communities 
of Kaktovik, Nuiqsut, or Barrow. Thus, given the location and timing of 
site clearance and shallow hazards and ice gouge surveys in the 
Beaufort Sea, any such behavioral response by beluga to these 
activities would have a no significant effect on them as a subsistence 
resource.
    Belugas are a prevailing subsistence resource in the Chukchi Sea 
community of Pt. Lay. The Point Lay beluga hunt is concentrated in the 
first two weeks of July (but sometimes continues into August), when 
belugas are herded by hunters with boats into Kasegaluk Lagoon and 
harvested in shallow waters. Ice gouge survey activities in the Chukchi 
Sea will be scheduled to avoid the traditional subsistence beluga hunt 
in the community of Pt. Lay. Timing of any ice gouge survey activities 
will be coordinated via the nearest communication and call centers 
operating in the Chukchi Sea, presumably in Wainwright and Barrow.
(3) Seals
    Seals are an important subsistence resource and ringed seals make 
up the bulk of the seal harvest of both Kaktovik and Nuiqsut. Seals can 
be hunted year-round, but are taken in highest numbers in the summer 
months in the Beaufort Sea (MMS 2008). Seal-hunting trips can take 
Nuiqsut hunters several miles offshore; however, the majority of seal 
hunting takes place closer to shore. The mouth of the Colville River is 
considered a productive seal hunting area (AES 2009), as well as the 
edge of the sea ice. Lease blocks where site clearance and shallow 
hazards surveys will occur are located over 15 mi (24 km) from the 
mouth of the Colville River, so there is less chance for impact on 
subsistence hunting for seals. Ice gouge surveys in Mary Sachs Entrance 
in Camden Bay will be conducted (AES 2009) over 30 miles from the 
westernmost extent of seal hunting by Kaktovik hunters (AES 2009). The 
remainder of ice gouge lines will be

[[Page 27731]]

much further offshore than where Kaktovik seal hunts typically occur 
which is inside the barrier islands (AES 2009). It is assumed that 
effects on subsistence seal harvests would be negligible given the 
distances between Shell's proposed site clearance and shallow hazards 
and ice gouge surveys and the subsistence seal hunting areas of Nuiqsut 
and Kaktovik.
    Seals are an important subsistence resource in the Chukchi Sea 
community of Wainwright. Ringed seals make up the bulk of the seal 
harvest. Most ringed and bearded seals are harvested in the winter or 
in the spring (May-July) which is before Shell's ice gouge survey would 
commence, but some harvest continues into the open water period. 
Hunting that does occur during the open water season generally occurs 
within 10 miles of the coastline (AES 2009), while the majority of ice 
gouge survey activity will be much further offshore. Timing of 
activities will be coordinated via the nearest communication and call 
centers operating in the Chukchi Sea, presumably in Wainwright and 
Barrow. It is assumed that effects on subsistence seal harvests would 
be negligible given the timing and distances between Shell's proposed 
ice gouge survey and the subsistence seal hunting area of Wainwright.
    All survey activities will be operated in accordance with the 
procedures of Shell's Marine Mammal Monitoring and Mitigation Plan 
(4MP) that accompanies this program. This potential impact is mitigated 
by application of the procedures established in the 4MP and to be 
detailed in the POC. Adaptive mitigation measures may be employed 
during times of active scouting, whaling, or other subsistence hunting 
activities that occur within the traditional subsistence hunting areas 
of the potentially affected communities.
    Shell states that it will continue its adopted spatial and temporal 
operational strategy that, when combined with its community outreach 
and engagement program, will provide effective protection to the 
bowhead migration and subsistence hunt.
    Based on the above analysis, measures described in Shell's Draft 
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 Shell's 2010 open water marine survey activities 
in the Beaufort and Chukchi Seas.

Endangered Species Act (ESA)

    There are two marine mammal species listed as endangered under the 
ESA with confirmed or possible occurrence in the proposed project area: 
the bowhead whale and the humpback whale. NMFS' Permits, Conservation 
and Education Division has begun consultation with NMFS' Endangered 
Species Division under section 7 of the ESA on the issuance of an IHA 
to Shell 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 Shell's 2010 open 
water marine surveys in the Beaufort and Chukchi Seas, Alaska, provided 
the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: May 12, 2010.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2010-11860 Filed 5-17-10; 8:45 am]
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