[Federal Register Volume 75, Number 156 (Friday, August 13, 2010)]
[Notices]
[Pages 49710-49758]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-19950]



[[Page 49709]]

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Part V





Department of Commerce





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National Oceanic and Atmospheric Administration



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 Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to Open Water Marine Seismic Survey in the 
Beaufort and Chukchi Seas, Alaska; Notice

  Federal Register / Vol. 75 , No. 156 / Friday, August 13, 2010 / 
Notices  

[[Page 49710]]


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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 Seismic Survey in 
the Beaufort and Chukchi Seas, Alaska

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

ACTION: Notice; issuance of an incidental take authorization.

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) 
regulations, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to Shell Offshore Inc. 
(Shell) to take, by harassment, small numbers of 8 species of marine 
mammals incidental to a marine survey program, which includes site 
clearance and shallow hazards, ice gouge, and strudel scour surveys, in 
the Beaufort and Chukchi Seas, Alaska, during the 2010 Arctic open 
water season.

DATES: Effective August 6, 2010, through November 30, 2010.

ADDRESSES: Inquiry for information on the incidental take authorization 
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. A 
copy of the application containing a list of the references used in 
this document, NMFS' Environmental Assessment (EA) and Finding of No 
Significant Impact (FONSI), and the IHA 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#applications.
    Documents cited in this notice may 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 or Brad Smith, NMFS, Alaska Region, 
(907) 271-3023.

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. 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''].

    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.

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, 2010, 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

[[Page 49711]]

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.
    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 profilers 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 Shell's 2006 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 believes it unlikely 
that a marine mammal would be taken by this activity.
     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

[[Page 49712]]

record layers beneath the surface to about 20 feet (6 m). The AUV is 
more maneuverable and able to complete surveys more quickly 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 sub-bottom 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):
    Since the output frequencies from these acoustic instruments are 
above the upper-limits of marine mammal hearing range, 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 believes it 
unlikely that a marine mammal would be taken by this activity.
     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 believes it 
unlikely that a marine mammal would be taken by this activity.

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.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to Shell published in 
the Federal Register on May 18, 2010 (75 FR 27708). That notice 
described, in detail, Shell's proposed activity, the marine mammal 
species that may be affected by the activity, and the anticipated 
effects on marine mammals. During the 30-day public comment period, 
NMFS received five comment letters from the following: the Marine 
Mammal Commission (Commission); the Alaska Eskimo Whaling Commission 
(AEWC); the Inupiat Community of the Arctic Slope (ICAS); the North 
Slope Borough Office of the Mayor (NSB); and Alaska Wilderness League 
(AWL), Audubon Alaska, Center for Biological Diversity, Defenders of 
Wildlife, Earthjustice, Greenpeace, Natural Resources Defense Council, 
Northern Alaska Environmental Center, Ocean Conservancy, Oceana, 
Pacific Environment, Sierra Club, and World Wildlife Fund (collectively 
``AWL''), along with an attached letter from Dr. David E. Bain, a 
contract scientist for NMFS.
    The AEWC submitted several journal articles as attachments to its 
comment letters. NMFS acknowledges receipt of these documents but does 
not intend to address the specific articles themselves in the responses 
to comments, since these journal articles are merely used as citations 
in AEWC's comments. AEWC also submitted an unsigned, final version of 
the 2010 Conflict Avoidance Agreement (CAA), since Shell declined to 
sign the CAA. Dr. Bain also attached

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an in-review journal article he coauthored. Any comments specific to 
Shell's application that address the statutory and regulatory 
requirements or findings NMFS must make to issue an IHA are addressed 
in this section of the Federal Register notice.

General Comments

    Comment 1: AEWC and ICAS believe that NMFS should not issue 
incidental take authorizations for oil and gas-related activities given 
the current suspension of offshore drilling in Alaska and pending 
reorganization of the Minerals Management Service (MMS). AEWC and ICAS 
point out that the harm caused by an oil spill is not the only risk to 
marine mammals posed by oil and gas activities on the OCS and that 
there are concerns regarding underwater noise from geophysical 
activities and the threats posed to marine mammals from noise and 
chemical pollution, as well as increased vessel traffic. AEWC further 
claims that many times, NMFS issued IHAs over the objections of the 
scientific and subsistence communities as well as the agencies' own 
scientists.
    Response: The legal requirements and underlying analysis for the 
issuance of an IHA concerning take associated with seismic activities 
are unrelated to the moratorium on offshore drilling and reorganization 
of the MMS. In order to issue an authorization pursuant to Section 
101(a)(5)(D) of the MMPA, NMFS must determine that the taking by 
harassment of small numbers of marine mammal species or stocks will 
have a negligible impact on affected species or stocks, and will not 
have an unmitigable adverse impact on the availability of affected 
species or stocks for taking for subsistence uses. If NMFS is able to 
make these findings, the Secretary is required to issue an IHA. In the 
case of Shell's activities for 2010 (as described in the application, 
the notice of proposed IHA (75 FR 27708; May 18, 2010) and this 
document), NMFS determined that it was able to make the required MMPA 
findings. Additionally, as described later in this section and 
throughout this document, NMFS has determined that Shell's activities 
will not result in injury or mortality of marine mammals, and no injury 
or mortality is authorized under the IHA.
    As discussed in detail in the proposed IHA (75 FR 27708; May 18, 
2010), the EA for the issuance of IHAs to Shell and Statoil for the 
proposed open water marine and seismic surveys, and this document, NMFS 
has conducted a thorough analysis of the potential impacts of 
underwater anthropogenic sound (especially sound from geophysical 
surveys) on marine mammals. We have cited multiple studies and research 
that support NMFS' MMPA and National Environmental Policy Act (NEPA) 
determinations that the localized and short-term disturbance from 
seismic surveys, with strict mitigation and monitoring measures 
implemented, is likely to result in negligible impacts to marine 
mammals and no significant impact to the human environment, 
respectively. Although issuance of the IHA may be of concern to certain 
members of the public, the proposed issuance of the IHA was carefully 
reviewed and analyzed by NMFS scientists both at headquarters, through 
an Endangered Species Act (ESA) section 7 consultation at NMFS Alaska 
Regional Office, and by an independent bioacoustics expert and NMFS' 
National Marine Mammal Laboratory. Based on those reviews, NMFS staff 
in the Office of Protected Resources made appropriate changes to this 
document.
    Comment 2: ICAS points out that Native communities in Alaska have 
long been ignored in the race to find and develop offshore oil and gas 
resources and that the U.S. Government has consistently failed to 
comply with legal requirements that require consultation with local 
Native communities as proposals are being developed that affect native 
environments. Instead, both Federal agencies and the entities they 
permit make only token gestures at consultations with Native groups 
offering them only the opportunity for involvement after proposals are 
developed and after local knowledge would serve a useful purpose.
    Response: Regulations at 50 CFR 216.104(a)(12) require applicants 
for IHAs in Arctic waters to submit a Plan of Cooperation (POC), which, 
among other things, requires the applicant to meet with affected 
subsistence communities to discuss the proposed activities. 
Additionally, for many years, NMFS has conducted the Arctic Open Water 
Meeting, which brings together the Federal agencies, the oil and gas 
industry, and affected Alaska Native organizations to discuss the 
proposed activities and monitoring plans. Local knowledge is considered 
at these times, and it is not too late for that knowledge to serve a 
useful purpose. These communities are also afforded the opportunity to 
submit comments on the application and proposed IHA notice, which are 
then considered by NMFS before making a final determination on whether 
or not to issue an IHA.
    Comment 3: Executive Order 13175 requires Federal agencies to 
conduct government-to-government consultation when undertaking to 
formulate and implement policies that have tribal implications. Despite 
this explicit requirement, ICAS believes that NMFS has failed to 
consult with governing bodies of Native people who will be and have 
been affected by the decisions NMFS is making under the MMPA. NMFS must 
meet with ICAS and local Native villages on a government-to-government 
basis to discuss the proposed IHA, as well as appropriate mitigation 
and monitoring requirements.
    Response: NMFS recognizes the importance of the government-to-
government relationship and has taken steps to ensure that Alaska 
Natives play an active role in the management of Arctic species. For 
example, NOAA and the AEWC co-manage bowhead whales pursuant to a 
cooperative agreement. This agreement has allowed the AEWC to play a 
significant role in the management of a valuable resource by affording 
Alaska Natives the opportunity to protect bowhead whales and the Eskimo 
culture and to promote scientific investigation, among other purposes.
    In addition, NMFS works closely with Alaska Natives when 
considering whether to permit the take of marine mammals incidental to 
oil and gas operations. NMFS has met repeatedly over the years with 
Alaska Native representatives to discuss concerns related to NMFS' MMPA 
program in the Arctic, and has also taken into account recommended 
mitigation measures to reduce the impact of oil and gas operations on 
bowhead whales and to ensure the availability of marine mammals for 
taking for subsistence uses. Finally, NMFS has participated in Alaska 
Native community meetings in the past and will continue to do so, when 
feasible. NMFS most recently met with ICAS at its May monthly meeting 
in Barrow to discuss NMFS' role in minimizing impacts to marine mammals 
from oil and gas industry activities and asked the ICAS membership for 
specific recommendations. NMFS will continue to ensure that it meets 
its government-to-government responsibilities and will work closely 
with Alaska Natives to address their concerns.

MMPA Concerns

    Comment 4: AEWC notes their disappointment in NMFS for releasing 
for public comment an incomplete application from Shell that fails to 
provide the mandatory information required by the MMPA and NMFS' 
implementing regulations. AEWC requests that NMFS return Shell's 
application as incomplete, or else the agency risks making arbitrary 
and

[[Page 49714]]

indefensible determinations under the MMPA. The following is the 
information that AEWC believes to be missing from Shell's application: 
(1) A description of the ``age, sex, and reproductive condition'' of 
the marine mammals that will be impacted, particularly in regard to 
bowhead whales (50 CFR 216.104(a)(6)); (2) the economic ``availability 
and feasibility * * * of equipment, methods, and manner of conducting 
such activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, their habitat, and on their 
availability for subsistence uses, paying particular attention to 
rookeries, mating grounds, and areas of similar significance'' (50 CFR 
216.104(a)(11)); and (3) suggested means of learning of, encouraging, 
and coordinating any research related activities (50 CFR 
216.104(a)(14)). NSB also notes its concern about the lack of 
specificity regarding the timing and location of the proposed surveys, 
as well as the lack of specificity regarding the surveys themselves.
    Response: NMFS does not agree that it released an incomplete 
application for review during the public comment period. After NMFS' 
initial review of the application, NMFS submitted questions and 
comments to Shell on its application. After receipt and review of 
Shell's responses, which were incorporated into the final version of 
the IHA application that was released to the public for review and 
comment, NMFS made its determination of completeness and released the 
application, addenda, and the proposed IHA notice (75 FR 27708; May 18, 
2010). Regarding the three specific pieces of information believed to 
be missing by AEWC, Shell's original application included a description 
of the pieces of information that are required pursuant to 50 CFR 
216.104(a)(12).
    Information required pursuant to 50 CFR 216.104(a)(6) requires that 
an applicant submit information on the ``age, sex, and reproductive 
condition (if possible)'' of the number of marine mammals that may be 
taken. In the application, Shell described the species expected to be 
taken by harassment and provided estimates of how many of each species 
were expected to be taken during their activities. In most cases, it is 
very difficult to estimate how many animals, especially cetaceans, of 
each age, sex, and reproductive condition will be taken or impacted by 
seismic or site clearance and shallow hazards surveys.
    Shell also provided information on economic ``availability and 
feasibility * * * of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, their habitat, and on their 
availability for subsistence uses, paying particular attention to 
rookeries, mating grounds, and areas of similar significance'' (50 CFR 
216.104(a)(11)) in its IHA application. In its application, Shell 
states that four main mitigations regarding site clearance and shallow 
hazards surveys in the Beaufort Sea are proposed: (1) Timing and 
locations for active survey acquisition work; (2) to configure airguns 
in a manner that directs energy primarily down to the seabed thus 
decreasing the range of horizontal spreading of noise; (3) using a 
energy source which is as small as possible while still accomplishing 
the survey objectives; and (4) curtailing active survey work when the 
marine mammal observers sight visually (from shipboard) the presence of 
marine mammals within identified ensonified zones. Details of these 
mitigation measures are discussed further in the 4MP that is included 
in Shell's IHA application. In addition to these measures, NMFS' Notice 
of Proposed IHA (75 FR 27708, May 18, 2010) described mitigation 
measures proposed to be implemented by Shell (outlined in the 
application), as well as additional measures proposed by NMFS for 
inclusion in an IHA.
    Lastly, information required pursuant to 50 CFR 216.104(a)(14) was 
also included in Shell's application. Shell provided a list of 
researchers who could potentially receive results of their research 
activities who may find the data useful in their own research. 
Additionally, Shell states that it plans to deploy arrays of acoustic 
recorders in the Beaufort Sea in 2010, similar to those deployed in 
2007 and 2008 using DASARs supplied by Greeneridge. These directional 
acoustic systems permit localization of bowhead whale and other marine 
mammal vocalizations, and 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. NMFS also determined that Shell's 
application provides descriptions of the specified activities and 
specified geographic region.
    In conclusion, NMFS believes that Shell provided all of the 
necessary information to proceed with publishing a proposed IHA notice 
in the Federal Register.
    Comment 5: AEWC and NSB state that NMFS failed to issue a draft 
authorization for public review and comment. The plain language of both 
the MMPA and NMFS' implementing regulations require that NMFS provide 
the opportunity for public comment on the ``proposed incidental 
harassment authorization'' (50 CFR 216.104(b)(1)(i); 16 U.S.C. 1371 
(a)(5)(D)(iii)) and not just on the application itself as NMFS has done 
here. Given Shell's refusal to sign the CAA and without a complete 
draft authorization and accompanying findings, AEWC states that it 
cannot provide meaningful comments on Shell's proposed activities, ways 
to mitigate the impacts of those activities on marine mammals, and 
measures that are necessary to protect subsistence uses and sensitive 
resources.
    Response: The May 18, 2010 proposed IHA notice (75 FR 27708) 
contained all of the relevant information needed by the public to 
provide comments on the proposed authorization itself. The notice 
contained the permissible methods of taking by harassment, means of 
effecting the least practicable impact on such species (i.e., 
mitigation), measures to ensure no unmitigable adverse impact on the 
availability of the species or stock for taking for subsistence use, 
requirements pertaining to the monitoring and reporting of such taking, 
including requirements for the independent peer review of the proposed 
monitoring plan. The notice provided detail on all of these points and, 
in NMFS view, allowed the public to comment on the proposed 
authorization and inform NMFS' final decision. Additionally, the notice 
contained NMFS' preliminary findings of negligible impact and no 
unmitigable adverse impact.
    The signing of a CAA is not a requirement to obtain an IHA. The CAA 
is a document that is negotiated between and signed by the industry 
participant, AEWC, and the Village Whaling Captains' Associations. NMFS 
has no role in the development or execution of this agreement. Although 
the contents of a CAA may inform NMFS' no unmitigable adverse impact 
determination for bowhead and beluga whales and ice seals, the signing 
of it is not a requirement. While a CAA has not been signed and a final 
version agreed to by industry participants, AEWC, and the Village 
Whaling Captains' Associations, NMFS was provided with a copy of the 
version ready for signature by AEWC. NMFS has reviewed the CAA and 
included several measures from the document which relate to marine 
mammals and avoiding conflicts with subsistence hunts in the IHA. Some 
of

[[Page 49715]]

the conditions which have been added to the IHA include: (1) Avoiding 
concentrations of whales and reducing vessel speed when near whales; 
(2) flying at altitudes above 457 m (1,500 ft) unless involved in 
marine mammal monitoring or during take-offs, landings, or in 
emergencies situations; (3) conducting sound source verification 
measurements; and (4) participating in the Communication Centers. 
Despite the lack of a signed CAA for 2010 activities, NMFS is confident 
that the measures contained in the IHA will ensure no unmitigable 
adverse impact to subsistence users.
    Comment 6: AEWC and NSB argue that Shell has not demonstrated that 
its proposed activities would take only ``small numbers of marine 
mammals of a species or population stock,'' resulting in no more than a 
``negligible impact'' on a species or stock. In addition, NSB argues 
that NMFS has not adequately analyzed harassment associated with 
received levels of noise below 160 dB.
    Response: NMFS believes that it provided sufficient information in 
its proposed IHA notice (75 FR 27708; May 18, 2010) to make the small 
numbers and negligible impact determinations and that the best 
scientific information available was used to make those determinations. 
While some published articles indicate that certain marine mammal 
species may avoid seismic vessels at levels below 160 dB, NMFS does not 
consider that these responses rise to the level of a take, as defined 
in the MMPA. While studies, such as Miller et al. (1999), have 
indicated that some bowhead whales may have started to deflect from 
their migratory path 35 km (21.7 mi) from the seismic vessel, it should 
be pointed out that these minor course changes are during migration 
and, as described in MMS' 2006 Final Programmatic Environmental 
Assessment (PEA), have not been seen at other times of the year and 
during other activities. To show the contextual nature of this minor 
behavioral modification, recent monitoring studies of Canadian seismic 
operations indicate that feeding, non-migratory bowhead whales do not 
move away from a noise source at an SPL of 160 dB. Therefore, while 
bowheads may avoid an area of 20 km (12.4 mi) around a noise source, 
when that determination requires a post-survey computer analysis to 
find that bowheads have made a 1 or 2 degree course change, NMFS 
believes that does not rise to a level of a ``take,'' as the change in 
bearing is due to animals sensing the noise and avoiding passage 
through the ensonified area during their migration, and should not be 
considered as being displaced from their habitat. NMFS therefore 
continues to estimate ``takings'' under the MMPA from impulse noises, 
such as seismic, as being at a distance of 160 dB (re 1 [mu]Pa). As 
explained throughout this Federal Register notice, it is highly 
unlikely that marine mammals would be exposed to SPLs that could result 
in serious injury or mortality. The best scientific information 
indicates that an auditory injury is unlikely to occur, as apparently 
sounds need to be significantly greater than 180 dB for injury to occur 
(Southall et al., 2007). The 180-dB radius for the airgun array to be 
used by Shell is 125 m (410 ft). Therefore, if injury were possible 
from Shell's activities, the animal would need to be closer than 125 m 
(410 ft). However, based on the configuration of the airgun array and 
streamers, it is highly unlikely that a marine mammal would be that 
close to the seismic vessel. Mitigation measures described later in 
this document will be implemented should a marine mammal enter this 
small zone around the airgun array.
    Regarding the ``small numbers'' issue raised by the AEWC and NSB, 
NMFS has provided estimates on the number of marine mammals that could 
be taken as a result of Shell's proposed marine surveys, and the 
estimated takes from these proposed activities are all under 3 percent 
for affected marine mammal populations (see Potential Number of Takes 
by Harassment section below).

Impacts to Marine Mammals

    Comment 7: AEWC notes that based on the density estimates, Shell is 
predicting that an average of 381 and a maximum of 394 Bering-Chukchi-
Beaufort (B-C-B) stock of bowhead whales may be exposed to seismic 
sounds at received levels above 160 dB. AEWC states that these are by 
no means ``small numbers'' of marine mammals that will be subjected to 
impacts as a result of Shell's operations.
    Response: NMFS determined that the small numbers requirement has 
been satisfied. Shell has predicted that an average of 381 individuals 
of the B-C-B stock of bowhead whales would be exposed to noise received 
levels above 160 dB as the result of Shell's proposed marine surveys, 
and NMFS assumes that animals exposed to received levels above 160 dB 
are taken. However, because of the tendency of whales to avoid the 
source to some degree, and the fact that both the whales and the source 
are both moving through an area, the majority of the exposures would 
likely occur at levels closer to 160 dB (not higher levels) and the 
impacts would be expected to be relatively low-level and not of a long 
duration. NMFS addresses ``small numbers'' in terms relative to the 
stock or population size. The Level B harassment take estimate of 381 
bowhead whales is a small number in relative terms, because of the 
nature of the anticipated responses and in that it represents only 2.67 
percent of the regional stock size of that species (14,247), if each 
``exposure'' at 160 dB represents an individual bowhead whale. 
Additionally, the percentage would be even lower if animals move out of 
the seismic area in a manner that does not result in a take at all.
    Comment 8: AWL, NSB, and AEWC noted that NMFS has acknowledged that 
permanent threshold shift (PTS) qualifies as a serious injury. 
Therefore, if an acoustic source at its maximum level has the potential 
to cause PTS and thus lead to serious injury, it would not be 
appropriate to issue an IHA for the activity (60 FR 28381, May 31, 
1995). AEWC states that therefore an LOA is required here. While the 
airguns proposed by Shell are smaller than those associated with 
typical 2D/3D deep marine surveys, the noise they produce is still 
considerable, as evidenced by the estimated 120 dB radius that extends 
out to 14,000 m.
    Response: In the proposed rule to implement the process to apply 
for and obtain an IHA, NMFS stated that authorizations for harassment 
involving the ``potential to injure'' would be limited to only those 
that may involve non-serious injury (60 FR 28379; May 31, 1995). While 
the Federal Register notice cited by the commenters states that NMFS 
considered PTS to be a serious injury (60 FR 28379; May 31, 1995), our 
understanding of anthropogenic sound and the way it impacts marine 
mammals has evolved since then, and NMFS no longer considers PTS to be 
a serious injury. NMFS has defined ``serious injury'' in 50 CFR 216.3 
as ``* * * any injury that will likely result in mortality.'' There are 
no data that suggest that PTS would be likely to result in mortality, 
especially the limited degree of PTS that could hypothetically be 
incurred through exposure of marine mammals to seismic airguns at the 
level and for the duration that are likely to occur in this action.
    Further, as stated several times in this document and previous 
Federal Register notices for seismic activities, 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). PTS is thought to occur several decibels above that inducing 
mild temporary threshold shift (TTS), the mildest form of hearing 
impairment (a non-injurious effect).

[[Page 49716]]

NMFS concluded that cetaceans and pinnipeds should not be exposed to 
pulsed underwater noise at received levels exceeding, respectively, 180 
and 190 dB re 1 [mu]Pa (rms). The established 180- and 190-dB re 1 
[mu]Pa (rms) criteria are 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 later in this document, 
data that are now available imply that TTS is unlikely to occur unless 
bow-riding odontocetes are exposed to airgun pulses much stronger than 
180 dB re 1 Pa rms (Southall et al. 2007). Additionally, NMFS has 
required monitoring and mitigation measures to negate the possibility 
of marine mammals being seriously injured as a result of Shell's 
activities. In the proposed IHA, NMFS determined that Shell's 
activities are unlikely to even result in TTS. Based on this 
determination and the explanation provided here, PTS is also not 
expected. Therefore, an IHA is appropriate.
    Comment 9: AWL, Dr. Bain, NSB, and AEWC state that NMFS has not 
adequately considered whether marine mammals may be harassed at 
received levels significantly lower than 160 dB and that NMFS did not 
use the best scientific evidence in setting the sound levels against 
which take was assessed. They state that NMFS calculated harassment 
from Shell's proposed surveying based on the exposure to marine mammals 
to sounds at or above 160 dB and that this uniform approach to 
harassment does not take into account known reactions of marine mammals 
in the Arctic to levels of noise far below 160 dB. These comments state 
that bowhead, gray, killer, and beluga whales and harbor porpoise react 
to sounds lower than 160 dB.
    Citing several papers on killer whales and harbor porpoise, Dr. 
Bain states that major behavioral changes of these animals appear to be 
associated with received levels of around 135 dB re 1 [mu]Pa, and that 
minor behavioral changes can occur at received levels from 90-110 dB re 
1 [mu]Pa or lower. He also states that belugas have been observed to 
respond to icebreakers by swimming rapidly away at distances up to 80 
km, where received levels were between 94 and 105 dB re 1 [mu]Pa. 
Belugas exhibited minor behavioral changes such as changes in 
vocalization, dive patterns, and group composition at distances up to 
50 km (NRC 2003), where received levels were likely around 120 dB.
    AEWC also states that in conducting scoping on its national 
acoustic guidelines for marine mammals, NMFS noted that the existing 
system for determining take (i.e., the 160 dB mark) ``considers only 
the sound pressure level of an exposure but not its other attributes, 
such as duration, frequency, or repetition rate, all of which are 
critical for assessing impacts on marine Mammals'' and ``also assumes a 
consistent relationship between rms (root-mean-square) and peak 
pressure values for impulse sounds, which is known to be inaccurate 
under certain (many) conditions'' (70 FR 1871, 1873; January 11, 2005). 
Thus, NMFS itself has recognized that 160 dB (rms) is not an adequate 
measure. AEWC argues that current scientific research establishes that 
120 dB (rms) is a more appropriate measure for impacts to marine 
mammals.
    Response: The best information available to date for reactions by 
bowhead whales to noise, such as seismic, is based on the results from 
the 1998 aerial survey (as supplemented by data from earlier years) as 
reported in Miller et al. (1999). In 1998, bowhead whales below the 
water surface at a distance of 20 km (12.4 mi) from an airgun array 
received pulses of about 117-135 dB re 1 [mu]Pa rms, depending upon 
propagation. Corresponding levels at 30 km (18.6 mi) were about 107-126 
dB re 1 [mu]Pa rms. Miller et al. (1999) surmise that deflection may 
have begun about 35 km (21.7 mi) to the east of the seismic operations, 
but did not provide SPL measurements to that distance and noted that 
sound propagation has not been studied as extensively eastward in the 
alongshore direction, as it has northward, in the offshore direction. 
Therefore, while this single year of data analysis indicates that 
bowhead whales may make minor deflections in swimming direction at a 
distance of 30-35 km (18.6-21.7 mi), there is no indication that the 
SPL where deflection first begins is at 120 dB; it could be at another 
SPL lower or higher than 120 dB. Miller et al. (1999) also note that 
the received levels at 20-30 km (12.4-18.6 mi) were considerably lower 
in 1998 than have previously been shown to elicit avoidance in bowheads 
exposed to seismic pulses. However, the seismic airgun array used in 
1998 was larger than the ones used in 1996 and 1997. Therefore, NMFS 
believes that it cannot scientifically support adopting any single SPL 
value below 160 dB and apply it across the board for all species and in 
all circumstances. Second, these minor course changes occurred during 
migration and, as indicated in MMS' 2006 PEA, have not been seen at 
other times of the year and during other activities. Third, as stated 
in the past, NMFS does not believe that minor course corrections during 
a migration equate to ``take'' under the MMPA. This conclusion is based 
on controlled exposure experiments conducted on migrating gray whales 
exposed to the U.S. Navy's low frequency sonar (LFA) sources (Tyack 
2009). When the source was placed in the middle of the migratory 
corridor, the whales were observed deflecting around the source during 
their migration. However, such minor deflection is considered not to be 
biologically significant. To show the contextual nature of this minor 
behavioral modification, recent monitoring studies of Canadian seismic 
operations indicate that when, not migrating, but involved in feeding, 
bowhead whales do not move away from a noise source at an SPL of 160 
dB. Therefore, while bowheads may avoid an area of 20 km (12.4 mi) 
around a noise source, when that determination requires a post-survey 
computer analysis to find that bowheads have made a 1 or 2 degree 
course change, NMFS believes that does not rise to a level of a 
``take.'' NMFS therefore continues to estimate ``takings'' under the 
MMPA from impulse noises, such as seismic, as being at a distance of 
160 dB (re 1 [mu]Pa). Although it is possible that marine mammals could 
react to any sound levels detectable above the ambient noise level 
within the animals' respective frequency response range, this does not 
mean that such animals would react in a biologically significant way. 
According to experts on marine mammal behavior, the degree of reaction 
which constitutes a ``take,'' i.e., a reaction deemed to be 
biologically significant that could potentially disrupt the migration, 
breathing, nursing, breeding, feeding, or sheltering, etc., of a marine 
mammal is complex and context specific, and it depends on several 
variables in addition to the received level of the sound by the 
animals. These additional variables include, but are not limited to, 
other source characteristics (such as frequency range, duty cycle, 
continuous vs. impulse vs. intermittent sounds, duration, moving vs. 
stationary sources, etc.); specific species, populations, and/or 
stocks; prior experience of the animals (naive vs. previously exposed); 
habituation or sensitization of the sound by the animals; and behavior 
context (whether the animal perceives the sound as predatory or simply 
annoyance), etc. (Southall et al. 2007).

[[Page 49717]]

    The references cited in the comment letters address different 
source characteristics (continuous sound rather than impulse sound that 
are planned for the proposed shallow hazard and site clearance surveys) 
or species (killer whales and harbor proposes) that rarely occur in the 
proposed Arctic action area. Some information about the responses of 
bowhead and gray whales to seismic survey noises has been acquired 
through dedicated research and marine mammal monitoring studies 
conducted during prior seismic surveys. Detailed descriptions regarding 
behavioral responses of these marine mammals to seismic sounds are 
available (e.g., Richardson et al. 1995; review by Southall et al. 
2007), and are also discussed in this document. Additionally, as Shell 
does not intend to use ice-breakers during its operations, statements 
regarding beluga reactions to icebreaker noise are not relevant to this 
activity.
    Regarding the last point raised in this comment by AEWC, NMFS 
recognizes the concern. However, NMFS does not agree with AEWC's 
statement that current scientific research establishes that 120 dB 
(rms) is a more appropriate measure for impacts to marine mammals for 
reasons noted above. Based on the information and data summarized in 
Southall et al. (2007), and on information from various studies, NMFS 
believes that the onset for behavioral harassment is largely context 
dependent, and there are many studies showing marine mammals do not 
show behavioral responses when exposed to multiple pulses at received 
levels above 160 dB re 1 [mu]Pa (e.g., Malme et al. 1983; Malme et al. 
1984; Richardson et al. 1986; Akamatsu et al. 1993; Madsen and 
M[oslash]hl 2000; Harris et al. 2001; Miller et al. 2005). Therefore, 
although using a uniform SPL of 160-dB for the onset of behavioral 
harassment for impulse noises may not capture all of the nuances of 
different marine mammal reactions to sound, it is an appropriately 
conservative way to manage and regulate anthropogenic noise impacts on 
marine mammals. Therefore, unless and until an improved approach is 
developed and peer-reviewed, NMFS will continue to use the 160-dB 
threshold for determining the level of take of marine mammals by Level 
B harassment for impulse noise (such as from airguns).
    Comment 10: NSB and AWL note that this IHA, as currently proposed, 
is based on uncertainties that are not allowed under the MMPA. Citing 
comments made by NMFS on recent MMS Lease Sale Environmental Impact 
Statements, NSB notes that NMFS stated that without more current and 
thorough data on the marine mammals in the Chukchi Sea and their use of 
these waters, it would be difficult to make the findings required by 
the MMPA. NSB notes that NMFS noted that the ``continued lack of basic 
audiometric data for key marine mammal species'' that occur throughout 
the Chukchi Sea inhibits the ``ability to determine the nature and 
biological significance of exposure to various levels of both 
continuous and impulsive oil and gas activity sounds.''
    Response: NMFS agrees that while there may be some uncertainty on 
the current status of some marine mammal species in the Chukchi Sea and 
on impacts to marine mammals from seismic surveys, the best available 
information supports our findings. NMFS is currently proposing to 
conduct new population assessments for Arctic pinniped species, and 
current information is available on-line through the Stock Assessment 
Reports (SARs). Moreover, NMFS has required the industry to implement a 
monitoring and reporting program to collect additional information 
concerning effects to marine mammals.
    In regard to impacts, there is no indication that seismic survey 
activities are having a long-term impact on marine mammals. For 
example, apparently, bowhead whales continued to increase in abundance 
during periods of intense seismic activity in the Chukchi Sea in the 
1980s (Raftery et al. 1995; Angliss and Outlaw 2007), even without 
implementation of current mitigation requirements. As a result, NMFS 
believes that seismic survey noise in the Arctic will affect only small 
numbers of and have no more than a negligible impact on marine mammals 
in the Chukchi Sea. As explained in this document and based on the best 
available information, NMFS has determined that Shell's activities will 
affect only small numbers of marine mammals, will have a negligible 
impact on affected species or stocks, and will not have an unmitigable 
adverse impact on subsistence uses of the affected species or stocks.
    Comment 11: AEWC notes that stranded marine mammals or their 
carcasses are also a sign of injury. NMFS states in its notice that it 
``does not expect any marine mammal will * * * strand as a result of 
the proposed survey'' (75 FR 27708; May 18, 2010). In reaching this 
conclusion, NMFS claims that strandings have not been recorded for the 
Beaufort and Chukchi Seas. AEWC states that the Department of Wildlife 
Management of NSB has completed a study documenting 25 years worth of 
stranding data and showing that five dead whales were reported in 2008 
alone in comparison with the five dead whales that were reported in the 
same area over the course of 25 years (Rosa 2009).
    In light of the increase in seismic operations in the Arctic since 
2006, AEWC says that NSB's study raises serious concerns about the 
impacts of these operations and their potential to injure marine 
mammals. AEWC states that while they think this study taken together 
with the June 2008 stranding of ``melon headed whales off Madagascar 
that appears to be associated with seismic surveys'' (75 FR 27708; May 
18, 2010) demonstrate that seismic operations have the potential to 
injure marine mammals beyond beaked whales (and that Shell needs to 
apply for an LOA for its operations), certainly NSB's study shows that 
direct injury of whales is on-going. AEWC states that these direct 
impacts must be analyzed and explanations sought out before additional 
activities with the potential to injure marine mammals are authorized, 
and that NMFS must explain how, in light of this new information, 
Shell's application does not have the potential to injure marine 
mammals.
    Response: NMFS has reviewed the information provided by AEWC 
regarding marine mammal strandings in the Arctic. The Rosa (2009) paper 
cited by AEWC does not provide any evidence linking the cause of death 
for the bowhead carcasses reported in 2008 to seismic operations. 
Additionally, the increased reporting of carcasses in the Arctic since 
2006 may also be a result of increased reporting effort and does not 
necessarily indicate that there were fewer strandings prior to 2008. 
Marine mammal observers (MMOs) aboard industry vessels in the Beaufort 
and Chukchi Seas have been required to report sightings of injured and 
dead marine mammals to NMFS as part of the IHA requirements only since 
2006.
    Regarding the June 2008 stranding of melon headed whales off 
Madagascar, information available to NMFS at this time indicates that 
the seismic airguns were not active around the time of the stranding. 
While the Rosa (2009) study does present information regarding the 
injury of whales in the Arctic, it does not link the cause of the 
injury to seismic survey operations. As NMFS has stated previously, the 
evidence linking marine mammal strandings and seismic surveys remains 
tenuous at best. Two papers, Taylor et al. (2004) and Engel et al. 
(2004) reference seismic signals as a possible cause for a marine 
mammal stranding.

[[Page 49718]]

    Taylor et al. (2004) noted two beaked whale stranding incidents 
related to seismic surveys. The statement in Taylor et al. (2004) was 
that the seismic vessel was firing its airguns at 1300 hrs on September 
24, 2004, and that between 1400 and 1600 hrs, local fishermen found 
live stranded beaked whales 22 km (12 nm) from the ship's location. A 
review of the vessel's trackline indicated that the closest approach of 
the seismic vessel and the beaked whales stranding location was 18 nm 
(33 km) at 1430 hrs. At 1300 hrs, the seismic vessel was located 25 nm 
(46 km) from the stranding location. What is unknown is the location of 
the beaked whales prior to the stranding in relation to the seismic 
vessel, but the close timing of events indicates that the distance was 
not less than 18 nm (33 km). No physical evidence for a link between 
the seismic survey and the stranding was obtained. In addition, Taylor 
et al. (2004) indicates that the same seismic vessel was operating 500 
km (270 nm) from the site of the Galapagos Island stranding in 2000. 
Whether the 2004 seismic survey caused the beaked whales to strand is a 
matter of considerable debate (see Cox et al. 2006). However, these 
incidents do point to the need to look for such effects during future 
seismic surveys. To date, follow up observations on several scientific 
seismic survey cruises have not indicated any beaked whale stranding 
incidents.
    Engel et al. (2004), in a paper presented to the IWC in 2004 (SC/
56/E28), mentioned a possible link between oil and gas seismic 
activities and the stranding of 8 humpback whales (7 off the Bahia or 
Espirito Santo States and 1 off Rio de Janeiro, Brazil). Concerns about 
the relationship between this stranding event and seismic activity were 
raised by the International Association of Geophysical Contractors 
(IAGC). The IAGC (2004) argues that not enough evidence is presented in 
Engel et al. (2004) to assess whether or not the relatively high 
proportion of adult strandings in 2002 is anomalous. The IAGC contends 
that the data do not establish a clear record of what might be a 
``natural'' adult stranding rate, nor is any attempt made to 
characterize other natural factors that may influence strandings. As 
stated previously, NMFS remains concerned that the Engel et al. (2004) 
article appears to compare stranding rates made by opportunistic 
sightings in the past with organized aerial surveys beginning in 2001. 
If so, then the data are suspect.
    Finally, if bowhead and gray whales react to sounds at very low 
levels by making minor course corrections to avoid seismic noise, and 
mitigation measures require Shell to ramp-up the seismic array to avoid 
a startle effect, strandings such as those observed in the Bahamas in 
2000 are highly unlikely to occur in the Arctic Ocean as a result of 
seismic activity. Therefore, NMFS does not expect any marine mammals 
will incur serious injury or mortality as a result of Shell's 2010 
survey operations, so an LOA is not needed.
    Lastly, Shell is required to report all sightings of dead and 
injured marine mammals to NMFS and to notify the Marine Mammal Health 
and Stranding Response Network. However, Shell is not permitted to 
conduct necropsies on dead marine mammals. Necropsies can only be 
performed by people authorized to do so under the Marine Mammal Health 
and Stranding Response Program MMPA permit. NMFS is currently 
considering different methods for marking carcasses to reduce the 
problem of double counting. However, a protocol has not yet been 
developed, so marking is not required in the IHA.
    Comment 12: AEWC and NSB state that research is increasingly 
showing that marine mammals may remain within dangerous distances of 
seismic operations rather than leave a valued resource such as a 
feeding ground (see Richardson 2004). The International Whaling 
Commission (IWC) scientific committee has indicated that the lack of 
deflection by feeding whales in Camden Bay (during Shell seismic 
activities) likely shows that whales will tolerate and expose 
themselves to potentially harmful levels of sound when needing to 
perform a biologically vital activity, such as feeding (mating, giving 
birth, etc.). Thus, the noise from Shell's proposed operations could 
injure marine mammals if they are close enough to the source. NSB 
further states that NMFS has not adequately analyzed the potential for 
serious injury.
    Response: If marine mammals, such as bowhead whales, remain near a 
seismic operation to perform a biologically vital activity, such as 
feeding, depending on the distance from the vessel and the size of the 
160-dB radius, the animals may experience some Level B harassment. A 
detailed analysis on potential impacts of anthropogenic noise 
(including noise from seismic airguns and other active acoustic sources 
used in geophysical surveys) is provided in the proposed IHA (75 FR 
27708; May 18, 2010) and in this document. Based on the analysis, NMFS 
believes that it is unlikely any animals exposed to noise from Shell's 
proposed marine surveys would be exposed to received levels that could 
cause TTS (a non-injurious Level B harassment). Therefore, it is even 
less likely that marine mammals would be exposed to levels of sound 
from Shell's activity that could cause PTS (a non-lethal Level A 
harassment).
    In addition, depending on the distance of the animals from the 
vessel and the number of individual whales present, certain mitigation 
measures are required to be implemented. If an aggregation of 12 or 
more mysticete whales are detected within the 160-dB radius, then the 
airguns must be shutdown until the aggregation is no longer within that 
radius. Additionally, if any whales are sighted within the 180-dB 
radius or any pinnipeds are sighted within the 190-dB radius of the 
active airgun array, then either a power-down or shutdown must be 
implemented immediately. For the reasons stated throughout this 
document, NMFS has determined that Shell's operations will not injure, 
seriously injure, or kill marine mammals.
    Comment 13: AEWC states that NMFS does little to assess whether 
Level A harassment is occurring as a result of the deflection of marine 
mammals as a result of Shell's proposed operations. Deflected marine 
mammals may suffer impacts due to masking of natural sounds including 
calling to others of their species, physiological damage from stress 
and other non-auditory effects, harm from pollution of their 
environment, tolerance, and hearing impacts (see Nieukirk et al. 2004). 
Not only do these operations disrupt the animals' behavioral patterns, 
but they also create the potential for injury by causing marine mammals 
to miss feeding opportunities, expend more energy, and stray from 
migratory routes when they are deflected. Dr. Bain also states that 
there are three main ways that minor behavioral changes, when 
experienced by numerous individuals for extended periods of time, can 
affect population growth: Increased energy expenditure, reduced food 
acquisition, and stress (Trites and Bain 2000).
    Response: See the response to comment 9 regarding the potential for 
injury. The paper cited by AEWC (Nieukirk et al. 2004) tried to draw 
linkages between recordings of fin, humpback, and minke whales and 
airgun signals in the western North Atlantic; however, the authors note 
the difficulty in assessing impacts based on the data collected. The 
authors also state that the effects of airgun activity on baleen whales 
is unknown and then cite to Richardson et al. (1995) for some possible 
effects, which AEWC lists in their comment. There is no statement in 
the cited study, however, about the

[[Page 49719]]

linkage between deflection and these impacts. While deflection may 
cause animals to expend extra energy, there is no evidence that this 
deflection is causing a significant behavioral change that will 
adversely impact population growth. In fact, bowhead whales continued 
to increase in abundance during periods of intense seismic activity in 
the Chukchi Sea in the 1980s (Raftery et al. 1995; Angliss and Outlaw 
2007). Therefore, NMFS does not believe that injury will occur as a 
result of Shell's activities. Additionally, Shell's total data 
acquisition activities would only ensonify 7.3 km\2\ to received levels 
above 160 dB of the Beaufort Sea (0.0016% of the entire Beaufort Sea). 
Therefore, based on the smaller radii associated with Shell's site 
clearance and shallow hazards surveys than the larger 2D or 3D seismic 
programs and the extremely small area of the Beaufort Sea where Shell 
will utilize airguns, it is unlikely that marine mammals will need to 
expend extra energy to locate prey or to have reduced foraging 
opportunities.
    Comment 14: Citing Erbe (2002), AEWC notes that any sound at some 
level can cause physiological damage to the ear and other organs and 
tissues. Placed in a context of an unknown baseline of sound levels in 
the Chukchi Sea, it is critically important that NMFS take a 
precautionary approach to permitting additional noise sources in this 
poorly studied and understood habitat. Thus, the best available science 
dictates that NMFS use a more cautious approach in addressing impacts 
to marine mammals from seismic operations.
    Response: The statement from Erbe (2002) does not take into account 
mitigation measures required in the IHA to reduce impacts to marine 
mammals. As stated throughout this document, based on the fact that 
Shell will be using a small airgun array (total discharge volume of 40 
in\3\) and will implement mitigation measures (i.e., ramp-up, power-
down, shutdown, etc.), NMFS does not believe that there will be any 
injury or mortality of marine mammals as a result of Shell's 
operations.
    Comment 15: AEWC states that in making its negligible impact 
determination, NMFS failed to consider several impacts: (1) Displacing 
marine mammals from feeding areas; (2) non-auditory, physiological 
effects, namely stress; (3) the possibility of vessel strikes needs to 
be considered in light of scientific evidence of harm from ship traffic 
to marine mammals; (4) impacts to marine mammal habitat, including 
pollution of the marine environment and the risk of oil spills, toxic, 
and nontoxic waste being discharged; (5) impacts to fish and other food 
sources upon which marine mammals rely; and (6) specific marine mammals 
that will be taken, including their age, sex, and reproductive 
condition. The first issue was also raised by Dr. Bain.
    Response: NMFS does not agree that these impacts were not 
considered. First, the area that would be ensonified by Shell's 
proposed open water marine surveys represents a small fraction of the 
total habitat of marine mammals in the Beaufort and Chukchi Seas. In 
addition, as the survey vessel is constantly moving, the ensonified 
zone where the received levels exceed 160 dB re 1 [micro]Pa (rms), 
which is estimated to be approximately 7.3 km\2\ at any given time, is 
constantly moving. Therefore, the duration during which marine mammals 
would potentially avoid the ensonified area would be brief. Therefore, 
NMFS does not believe marine mammals would be displaced from their 
customary feeding areas as a result of Shell's proposed marine surveys.
    Second, non-auditory, physiological effects, including stress, were 
analyzed in the Notice of Proposed IHA (75 FR 27708; May 18, 2010). No 
single marine mammal is expected to be exposed to high levels of sound 
for extended periods based on the size of the airgun array to be used 
by Shell and the fact that an animal would need to swim close to, 
parallel to, and at the same speed as the vessel to incur several high 
intensity pulses. This also does not take into account the mitigation 
measures described later in this document.
    Third, impacts resulting from vessel strikes and habitat pollution 
and impacts to fish were fully analyzed in NMFS' 2010 Final EA for 
Shell and Statoil's open water marine and seismic activities (NMFS 
2010). Additionally, the proposed IHA analyzed potential impacts to 
marine mammal habitat, including prey resources. That analysis noted 
that while mortality has been observed for certain fish species found 
in extremely close proximity to the airguns, S[aelig]tre and Ona (1996) 
concluded that mortality rates caused by exposure to sounds are so low 
compared to natural mortality that issues relating to stock recruitment 
should be regarded as insignificant.
    For the sixth point, please see the response to comment 4. The age, 
sex, and reproductive condition must be provided when possible. 
However, this is often extremely difficult to predict. Additional 
mitigation measures for bowhead cow/calf pairs, such as monitoring the 
120-dB radius and requiring shutdown when 4 or more cow/calf pairs 
enter that zone, were considered and required for this survey.
    Comment 16: AEWC states that in assessing the level of take and 
whether it is negligible, NMFS relied on flawed density estimates that 
call into question all of NMFS' preliminary conclusions. AEWC states 
that density data are lacking or outdated for almost all marine mammals 
that may be affected by Shell's operations in the Beaufort and Chukchi 
Seas, especially for the fall. AEWC provided a few species specific 
examples to show that NMFS failed to utilize the best available 
scientific studies in assessing Shell's application. AEWC argues that 
NMFS' guess at the number of beluga and bowhead whales relies on a 
study from Moore et al. that was published in 2000, that the density of 
bowhead whales was derived from limited aerial surveys conducted by 
industry operators, and that these estimates are contrary to the best 
available scientific information. AEWC also points out that NMFS makes 
no mention of the most recent Alaska Marine Mammal Stock Assessment 
Report (SAR) which was released this year, and that the Assessment 
cites to a 2003 study that documented bowheads ``in the Chukchi and 
Bering Seas in the summer'' that are ``thought to be a part of the 
expanding Western Arctic stock'' (Angliss and Allen 2009). While a 
study published in 2003 still is not a sufficient basis for a 2009 
density analysis, this study does show that additional information is 
available that indicates that the number of bowhead whales in the 
Chukchi may be higher than estimated by NMFS.
    Response: As required by the MMPA implementing regulations at 50 
CFR 216.102(a), NMFS has used the best scientific information available 
in assessing the level of take and whether it is negligible. Although 
most of the data NMFS depends on were collected over 10 years (1982-
1991) from aerial surveys offshore of northern Alaska (Moore et al. 
2000), these are the best scientific information available for bowhead 
and beluga whale density and distribution so far. Since approximately 
10 days of Shell's proposed shallow hazards and site clearance surveys 
are likely to occur during the fall period when bowheads are migrating 
through the Beaufort Sea, more conservative estimates were made to take 
account for this 10-day moving average presented by Richardson and 
Thomson (2002). Additionally, the 2003 study noted by AEWC in the 
bowhead whale Alaska Marine Mammal SAR discusses distribution, not 
density (Rugh et al. 2003). It was not cited because it is not useful 
for deriving density estimates.

[[Page 49720]]

Therefore, density estimates for bowhead and beluga whales using Moore 
et al. (2000) are based on the best available science.
    Comment 17: AEWC states that NMFS fails to explain how and why it 
reaches various conclusions in calculating marine mammal densities and 
what the densities are actually estimated to be once calculated. One 
example is NMFS' reliance on Moore et al. (2000) in making its density 
determinations. This study documented sightings of marine mammals but 
did not estimate the total number of animals present. AEWC states that 
NMFS's practices have resulted in entirely arbitrary calculations of 
the level of take of marine mammals and whether such takes constitute 
``small numbers'' or a ``negligible impact'' as a result of Shell's 
proposal.
    Response: All densities used in calculating estimated take of 
marine mammals based on the described operations are shown in Tables 6-
1 to 6-3 of Shell's application. Moore et al. (2000) provides line 
transect effort and sightings from aerial surveys for cetaceans in the 
Chukchi Sea. The kilometers of ``on-transect'' observer effort and 
number of sightings were used in the accepted line-transect density 
estimate equation described in Buckland et al. (2001). Species specific 
correction factors for animals that were not at the surface or that 
were at the surface but were not sighted [g(0)] and animals not sighted 
due to distance from the survey trackline [f(0)] used in the equation 
were taken from reports or publications on the same species or similar 
species if no values were available for a given species, that used the 
same survey platform. Additional explanations regarding the 
calculations of marine mammal densities are provided in the Shell's 
application and the Federal Register notice for the proposed IHA (75 FR 
27708; May 18, 2010). Therefore, NMFS believes the methodology used in 
calculations of the level of take of marine mammals is scientifically 
well supported.
    Comment 18: AEWC is opposed to NMFS using ``survey data'' gathered 
by industry while engaging in oil and gas related activities and 
efforts to document their take of marine mammals. AEWC points out that 
such industry ``monitoring'' is designed to document the level of take 
occurring from the operation (see 75 FR 27724 and Shell's 4MP). AEWC 
argues that putting aside whether the methodologies employed are 
adequate for this purpose, they certainly are not adequate for 
assessing the density or presence of marine mammals that typically 
avoid such operations.
    Response: In making its determinations, NMFS uses the best 
scientific information available, as required by the MMPA implementing 
regulations. For some species, density estimates from sightings 
surveys, as well as from ``industry surveys'', were provided in the 
text of Shell's application and the Notice of Proposed IHA for purposes 
of comparison. However, where information was available from sightings 
surveys (e.g., Moore et al. 2000; Bengtson et al. 2005), those 
estimates were used to calculate take. Data collected on industry 
vessels were only used when no other information was available. 
Additionally, while some Arctic marine mammal species have shown 
fleeing responses to seismic airguns, data is also collected on these 
vessels during periods when no active seismic data collection is 
occurring.
    Comment 19: AEWC states that as a general matter, when it comes to 
NMFS assessing the various stocks of marine mammals under the MMPA, it 
cannot use outdated data i.e., ``abundance estimates older than 8 
years'' because of the ``decline in confidence in the reliability of an 
aged abundance estimate'' (Angliss and Allen 2009) and the agency is 
thus unable to reach certain conclusions. Similarly, here, where data 
are outdated or nonexistent, NMFS should decide it cannot reach the 
necessary determinations. AEWC argues that these flaws in NMFS' 
analysis render the agency's preliminary determinations about the level 
of harassment and negligible impacts completely arbitrary.
    Response: The statements quoted by AEWC from Angliss and Allen 
(2009) are contained in species SARs where abundance estimates are 
older than 8 years. However, the full statement reads as follows: 
``However, the 2005 revisions to the SAR guidelines (NMFS 2005) state 
that abundance estimates older than 8 years should not be used to 
calculate PBR due to a decline in confidence in the reliability of an 
aged abundance estimate.'' Shell's activities are not anticipated to 
remove any individuals from the stock or population. Therefore, a 
recent estimate of PBR is not needed for NMFS to make the necessary 
findings under Section 101(a)(5)(D) of the MMPA. Additionally, Shell's 
application provides information (including data limitations) and 
references for its estimates of marine mammal abundance. Because AEWC 
has not provided information contrary to the data provided by Shell, 
and NMFS does not have information that these estimates are not 
reliable, NMFS considers these data to be the best available.
    Comment 20: AWL argues that the effects of ice gouge and strudel 
scour surveying should be considered. AWL states that NMFS' dismissal 
of potential effects based on marine mammal hearing is not adequately 
supported. AWL and Dr. Bain argue that NMFS' approach fails to take 
into consideration the fact that: (1) Juvenile whales, based on their 
smaller size, likely hear sounds of higher frequencies than adults of 
the same species; (2) that sound sources contain frequencies beyond the 
``normal'' frequency in the form of undertones, overtones, distortion, 
or noise; (3) NMFS failed to consider the beat frequency, that when a 
source simultaneously emits sound of more than one frequency, it will 
also emit energy at the difference between the two frequencies; (4) 
NMFS fails to take into account the fact that information about hearing 
abilities of bowhead whales is based on estimates since bowheads have 
not been the subject of direct testing and there is inherent 
uncertainty in these estimates; and (5) the Federal Register notice 
does not address the fact that toothed whales are sensitive to high-
frequency sounds including those over 100 kHz.
    Response: NMFS considered the potential effects of Shell's proposed 
ice gouge and strudel scour surveys in the Beaufort and Chukchi Seas 
(75 FR 27708; May 18, 2010). The reason NMFS does not think take of 
marine mammal is likely from ice gouge and strudel scour is because the 
active acoustic devices being used in these surveys are either in the 
frequency range above 180 kHz, which is beyond marine mammals 
functional hearing range, or with low source levels. In addition, due 
to their high-frequency nature, there is much absorption during sound 
propagation, which weakens much of the acoustic intensity within a 
relatively short range.
    Although NMFS recognizes much scientific information is still 
needed on marine mammal hearing capability and audiograms, studies over 
the past sixty years on key common species across several major 
taxonomy groups have provided overall hearing ranges of marine mammal 
species (see review in Richardson et al. 1995; Southall et al. 2007). 
These studies show that marine mammal hearing ranges follow certain 
patterns and can be divided into five functional hearing groups: low-
frequency cetacean (baleen whales), mid-frequency cetacean (mostly 
large to mid-size toothed whales, and delphinids), high-frequency 
cetacean (porpoises and river dolphins),

[[Page 49721]]

pinniped in water, and pinniped in air (Southall et al. 2007). Although 
it is possible that juvenile animals could have better hearing at high-
frequency ranges similar to humans, however, the overall sensitivity 
that defines hearing is based on species (or hearing groups) instead of 
age groups. Therefore, it is incorrect to assume that juvenile whales 
hear sounds of higher frequencies because of their small size, 
regardless of species and functional hearing groups. In addition, the 
reason that juvenile animals (including humans) have slightly better 
high-frequency hearing is related to age rather than size (the 
principle behind it is a biological phenomenon called presbycusis, or 
aging ear).
    Regarding point (2) concerning ``normal'' frequency, which was not 
defined in the comment, NMFS assumes that Dr. Bain refers to the 
frequenc(ies) outside the manufacturers' specs for their acoustic 
devices. Although these outlier noises could be a concern for high-
frequency acoustic sources, especially if the frequencies are within 
the sensitive hearing range of marine mammals, NMFS does not believe 
these noises have high acoustic intensities in most cases. 
Nevertheless, NMFS requested that Shell provide frequency spectra and 
source characteristics for all of its acoustic devices. Shell reported 
back that it was unable to obtain such specifications from 
manufacturers. However, Shell will be required to conduct measurements 
of power density spectra (frequency spectra) of its high frequency 
active acoustic sources (operating frequency >180 kHz) that will be 
used in its marine surveys against ambient background noise levels. The 
power density spectra of these high frequency active acoustic sources 
will be reported in 1/3-octave band and 1-Hz band from 10 Hz to 180 
kHz. The purpose for this measurement is to determine whether there is 
any acoustic energy within marine mammal hearing ranges that would be 
generated from operating these high frequency acoustic sources.
    If significant acoustic energy (broadband source level >160 dB re 1 
[mu]Pa @ 1 m in frequency band below 180 kHz) from these high frequency 
active acoustic sources exists within marine mammal hearing ranges, 
Shell is required to implement mitigation measures (such as 
establishing disturbance zones). Therefore, NMFS believes it unlikely 
that a marine mammal would be taken by this activity.
    In regard to point (3), in order to produce ``beat frequency,'' not 
only do the two sources have to be very close to each other, they also 
have to be perfectly synchronized. In the case of Shell's high-
frequency sonar, these two interfering frequencies will need to be 
produced by one device to use the non-linearity of water to 
purposefully generate the different frequency between two high 
frequencies. Even so, it is a very inefficient way to generate the beat 
frequency, with only a low percentage of the original intensity with 
very narrow beamwidth. Therefore, NMFS does not consider this to be an 
issue of concern.
    NMFS is aware that no direct measurements of hearing exist for 
these animals, and theories regarding their sensory capabilities are 
consequently speculative (for a detailed assessment by species using 
the limited available information, see Erbe 2002). In these species, 
hearing sensitivity has been estimated from behavioral responses (or 
lack thereof) to sounds at various frequencies, vocalization 
frequencies they use most, body size, ambient noise levels at the 
frequencies they use most, and cochlear morphometry and anatomical 
modeling (Richardson et al. 1995; Wartzok and Ketten 1999; Houser et 
al. 2001; Erbe 2002; Clark and Ellison 2004; Ketten et al. 2007). 
Though detailed information is lacking on the species level, the 
combined information strongly suggests that mysticetes are likely most 
sensitive to sound from perhaps tens of Hz to ~10 kHz (Southall et al. 
2007). Although hearing ranges for toothed whales (mid- and high-
frequency cetaceans) fall between 100s Hz to over 100 kHz, their most 
sensitive frequency lie between 10 to 90 kHz, and sensitivity falls 
sharply above 100 kHz.
    Comment 21: Dr. Bain states that changes in behavior resulting from 
noise exposure could lead to indirect injury in marine mammals in the 
wild. He presented several examples to suggest that marine mammals 
repeatedly exposed to Level B harassment could result in Level A takes: 
(1) Harbor porpoise were observed traveling at high speeds during 
exposure to mid-frequency sonar in Haro Strait in 2003 and that 
exhaustion from rapid flight could lead to mortality; (2) citing MMS' 
(2004) Environmental Assessment on Proposed Oil and Gas Lease Sale 195 
in the Beaufort Sea Planning Area (OCS EIS/EA MMS 2004-028) that 
feeding requires a prey density of 800 mg/m\3\ and his own observation, 
Dr. Bain is concerned displacement from highly productive feeding areas 
would negatively affect individual whales and that small cetaceans such 
as harbor porpoise would face a risk of death if they are unable to 
feed for periods as short as 48-72 hours, or they may move into habitat 
where they face an increased risk of predation; and (3) individual 
killer whales have been observed splitting from their pod when 
frightened by sonar and that other killer whales' separation from their 
social units has resulted in death.
    Response: NMFS agrees that it is possible that changes in behavior 
or auditory masking resulting from noise exposure could lead to injury 
in marine mammals under certain circumstances in the world, such as 
those examples/hypotheses raised by Dr. Bain. However, the assumption 
that Dr. Bain made that ``exhaustion from rapid flight leading to heart 
or other muscle damage'' could account for mortality merely because of 
exposure to airgun noise has no scientific basis. Also, it is not 
likely that received SPLs from the site clearance and shallow hazards 
surveys would cause drastic changes in behavior or auditory masking in 
marine mammals in the vicinity of the action area. First, marine 
mammals in the aforementioned examples and hypotheses were exposed to 
high levels of non-pulse intermittent sounds, such as military sonar, 
which has been shown to cause flight activities (e.g., Haro Strait 
killer whales); and continuous sounds such as the vessel, which could 
cause auditory masking when animals are closer to the source. The 
sources produced by the acoustic equipment and airguns for Shell's site 
clearance and shallow hazards surveys are impulse sounds used in 
seismic profiling, bathymetry, and seafloor imaging. Unlike military 
sonar, seismic pulses have an extremely short duration (tens to 
hundreds of milliseconds) and relatively long intervals (several 
seconds) between pulses. Therefore, the sound energy levels from these 
acoustic sources and small airguns are far lower in a given time 
period. Second, the intervals between each short pulse would allow the 
animals to detect any biologically significant signals, and thus avoid 
or prevent auditory masking. Although airgun pulses at long distances 
(over kilometers) may be ``stretched'' in duration and become non-pulse 
due to multipath propagation, the intervals between the non-pulse 
noises would still allow biologically important signals to be detected 
by marine mammals. Especially due to the relatively small source being 
used for the site clearance and shallow hazard surveys, the received 
levels at such long distances would be even lower (e.g., modeled 
received levels at 15 km are expected to be under 120 dB re 1 [mu]Pa). 
In addition, NMFS requires mitigation measures to ramp-up acoustic 
sources at a rate of no more than 6 dB per 5 min.

[[Page 49722]]

This ramp-up would prevent marine mammals from being exposed to high 
level noises without warning, thereby eliminating the possibility that 
animals would dramatically alter their behavior (i.e. from a 
``startle'' reaction). NMFS also believes that long-term displacement 
of marine mammals from a feeding area is not likely because the seismic 
vessel is constantly moving, and the maximum 160-dB ensonified radius 
is about 1.22 km, which would create an area of ensonification of 
approximately 7.3 km\2\ at any given moment, which constitutes a very 
small portion of the Beaufort Sea (0.0016 percent). In reality, NMFS 
expects the 160-dB ensonified zone to be smaller due to absorption and 
attenuation of acoustic energy in the water column.
    Comment 22: Citing research on long term adverse effects to whales 
and dolphins from whale watching activities (Trites and Bain 2000; Bain 
2002; Lusseau et al. 2009), Dr. Bain states that Level B behavioral 
harassment could be the primary threat to cetacean populations.
    Response: Although NMFS agrees that long-term, persistent, and 
chronic exposure to Level B harassment could have a profound and 
significant impact on marine mammal populations, such as described in 
the references cited by Dr. Bain, those examples do not reflect the 
impacts of seismic surveys to marine mammals for Shell's project. 
First, whale watching vessels are intentionally targeting and making 
close approaches to cetacean species so the tourists onboard can have a 
better view of the animals. Some of these whale/dolphin watching 
examples cited by Dr. Bain occurred in the coastal waters of the 
Northwest Pacific between April and October and for extended periods of 
time (``[r]ecreational and scientific whale watchers were active by 
around 6 a.m., and some commercial whale watching continued until 
around sunset''). Thus multiple vessels have been documented to be in 
relatively close proximity to whales for about 12 hours a day, six 
months a year, not counting some ``out of season'' whale watching 
activities and after dark commercial filming efforts. In addition, 
noise exposures to whales and dolphins from whale watching vessels are 
probably significant due to the vessels' proximity to the animals. To 
the contrary, Shell's proposed open-water shallow hazard and site 
clearance surveys, along with existing industrial operations in the 
Arctic Ocean, do not intentionally approach marine mammals in the 
project areas. Shell's survey locations are situated in a much larger 
Arctic Ocean Basin, which is far away from most human impacts. 
Therefore, the effects from each activity are remote and spread farther 
apart, as analyzed in NMFS' 2010 EA, as well as the MMS 2006 PEA. 
Shell's site clearance and shallow hazards activities would only be 
conducted between July and October for 60 days, weather permitting. In 
addition, although studies and monitoring reports from previous seismic 
surveys have detected Level B harassment of marine mammals, such as 
avoidance of certain areas by bowhead and beluga whales during the 
airgun firing, no evidence suggests that such behavioral modification 
is biologically significant or non-negligible (Malme et al. 1986; 1988; 
Richardson et al. 1987; 1999; Miller et al. 1999; 2005), as compared to 
marine mammals exposed to chronic sound from whale watching vessels, as 
cited by Dr. Bain. Therefore, NMFS believes that potential impacts to 
marine mammals in the Chukchi Sea by site clearance and shallow hazards 
surveys would be limited to Level B harassment only, and due to the 
limited scale and remoteness of the project in relation to a large 
area, such adverse effects would not accumulate to the point where 
biologically significant effects would be realized.
    Comment 23: Dr. Bain notes that NMFS uses different thresholds for 
continuous and pulsed sounds. Dr. Bain thus assumes that the motivation 
for this was to tie impact to SEL measurements of sound (as opposed to 
RMS or peak-to-peak measurements), which correlated well with TTS. Dr. 
Bain states that there is no evidence linking SEL to behavioral 
changes, and citing his paper (Bain and Williams, in review), Mr. Bain 
claims he found peak-to-peak level measurements correlated best with 
behavioral changes.
    Response: First, Dr. Bain's assumption regarding NMFS' use of 
different behavioral thresholds for impulse and non-impulse noises are 
incorrect. The reason for the difference is not to tie impact to SEL 
measurements of sound to behavioral change, rather, this difference 
(received level at 160 dB re 1 [mu]Pa for pulse and 120 dB re 1 [mu]Pa 
for non-pulse) came from many field observations and analyses (see 
review by Richardson et al. 1995; Southall et al. 2007) on measured 
avoidance responses in whales in the wild. Specifically, the 160 dB re 
1 [mu]Pa (rms) threshold was derived from data for mother-calf pairs of 
migrating gray whales (Malme et al. 1983; 1984) and bowhead whales 
(Richardson et al. 1985; Richardson et al. 1986) responding when 
exposed to seismic airguns (impulsive sound source). The 120 dB re 
1[mu]Pa (rms) threshold also originates from research on baleen whales, 
specifically migrating gray whales (Malme et al. 1984; predicted 50% 
probability of avoidance) and bowhead whales reacting when exposed to 
industrial (i.e., drilling and dredging) activities (non-impulsive 
sound source) (Richardson et al. 1990).
    Dr. Bain's attached paper (Bain and Williams, in review) reports 
the results of an examination of effects of large airgun arrays on 
behavior of marine mammals in the waters of British Columbia, Canada 
and Washington State, USA, using a small boat to monitor out to long 
ranges (1 to > 70 km from the seismic source vessel). The paper 
concludes that a significant relationship was observed between the 
magnitude of behavioral response and peak-to-peak received level and 
the long distances at which behavioral responses were observed (> 60 km 
for harbor porpoise), along with counter-productive behavior that 
occasionally brought individuals into higher-intensity acoustic zones. 
However, there are potential design flaws in the study. First, the 
paper states a launch carried aboard the seismic receiver vessel was 
placed in the water to perform received level measurements near marine 
mammals. When making acoustic measurements, the launch ``travelled 
along a line at approximately 20 km/h until either marine mammals were 
closely approached, or the launch had travelled 10 km.'' Therefore, it 
is highly likely that behavioral reactions from observed marine mammals 
were caused by the high-speed, close-approach of the launch, rather 
than from distant seismic airguns. This experiment design may explain 
the authors' observation of ``counter-productive behavioral responses'' 
that animals are moving into higher-intensity acoustic zones, which 
probably indicates that behavioral changes caused by Bain's launch 
greatly exceeded any behavioral change resulting from exposure to 
seismic airgun noise. Second, the authors of the paper also expressed 
``methodological concerns due to the subjectivity of observers.'' 
Nevertheless, this study concludes that harbor seal individuals were 
generally moving away from the airguns at exposure levels above 170 dB 
re 1 [mu]Pa (p-p) and that gray whales were observed at received levels 
up to approximately 170 dB re 1 [mu]Pa (p-p) exhibiting no obvious 
behavioral response. These observations contradict Mr. Bain's earlier 
comments that major behavioral effects result from noise in the 105-125 
dB range.
    Finally, Bain and Williams (in review) also state that the study 
``found that while airguns concentrated their sound output at low 
frequencies, substantial

[[Page 49723]]

high frequency energy (to at least 100 kHz) was also present.'' 
However, the paper provides no explanation as to how this conclusion 
was made. The accompanying power density spectrum (Figure 2 in Bain and 
Williams, in review) of the paper fails to show evidence that the 
frequencies above 1 kHz were mostly contributed from seismic airguns, 
and there was no indication at what distance this recording was made.

Subsistence Issues

    Comment 24: AEWC states that the nondiscretionary congressional 
directive that there will be no more than a negligible impact to marine 
mammals and no unmitigable adverse impact to the availability of marine 
mammals for subsistence taking is consistent with the MMPA's overall 
treatment of both marine mammal and subsistence protections. AEWC 
further states that Congress has set a ``moratorium on the taking * * * 
of marine mammals,'' 16 U.S.C. 1371(a), with the sole exemption 
provided for the central role of subsistence hunting by Alaska Natives. 
Thus, AEWC concludes that Congress has given priority to subsistence 
takes of marine mammals over all other exceptions to the moratorium, 
which may be applied for and obtained only if certain statutory and 
regulatory requirements are met. However, AEWC states that incidental 
harassment authorizations are available only for specified activities 
for which the Secretary makes the mandated findings. Thus, the pursuit 
of those activities is subordinated, by law, to the critical 
subsistence uses that sustain Alaska's coastal communities. NSB further 
states that NMFS has not adequately demonstrated that the proposed 
activities will not have ``an unmitigable adverse impact on the 
availability of such species or stock for taking for subsistence 
uses.''
    Response: The MMPA does not prohibit an activity from having an 
adverse impact on the availability of marine mammals for subsistence 
uses; rather, the MMPA requires NMFS to ensure the activity does not 
have an unmitigable adverse impact on the availability of such species 
or stocks for taking for subsistence uses. NMFS has defined 
``unmitigable adverse impact'' in 50 CFR 216.103 as an impact resulting 
from the specified activity: (1) That is likely to reduce the 
availability of the species to a level insufficient for a harvest to 
meet subsistence needs by: (i) Causing the marine mammals to abandon or 
avoid hunting areas; (ii) directly displacing subsistence users; or 
(iii) placing physical barriers between the marine mammals and the 
subsistence hunters; and (2) that cannot be sufficiently mitigated by 
other measures to increase the availability of marine mammals to allow 
subsistence needs to be met.
    For the determination of the unmitigable adverse impact analysis, 
NMFS, other government agencies, and affected stakeholder agencies and 
communities were provided a copy of the draft POC in March 2010, which 
outlined measures Shell would implement to ensure no unmitigable 
adverse impact to subsistence uses. The POC specifies times and areas 
to avoid in order to minimize possible conflicts with traditional 
subsistence hunts by North Slope villages for transit and open-water 
activities. Shell waited to begin activities until the close of the 
spring beluga hunt in the village of Point Lay. Shell has also 
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.
    Based on the measures contained in the IHA (and described later in 
this document), NMFS has determined that mitigation measures are in 
place to ensure that Shell's operations do not have an unmitigable 
adverse impact on the availability of marine mammal species or stocks 
for subsistence uses.

Mitigation and Monitoring Concerns

    Comment 25: NSB is concerned that MMOs cannot see animals at the 
surface when it is dark or during the day because of fog, glare, rough 
seas, the small size of animals such as seals, and the large portion of 
time that animals spend submerged. NSB also notes that Shell has 
acknowledged that reported sightings are only ``minimum'' estimates of 
the number of animals potentially affected by surveying.
    Response: NMFS recognizes the limitations of visual monitoring in 
darkness and other inclement weather conditions. Therefore, in the IHA 
to Shell, NMFS requires that no seismic airgun can be ramped up when 
the entire safety zones are not visible. However, Shell's operations 
will occur in an area where periods of darkness do not begin until 
early September. Beginning in early September, there will be 
approximately 1-3 hours of darkness each day, with periods of darkness 
increasing by about 30 min each day. By the end of the survey period, 
there will be approximately 8 hours of darkness each day. These 
conditions provide MMOs favorable monitoring conditions for most of the 
time.
    Comment 26: AEWC notes that Shell intends to employ marine mammal 
observers (``MMO'') and a ``190 and 180 dB safety radii for pinnipeds 
and cetaceans, respectively, and the 160 dB disturbance radii'' to 
mitigate these effects. However, AEWC states that the safety radii 
proposed by Shell do not negate these impacts. The safety radii only 
function as well as the observers on the vessels can see and report 
marine mammals within the radii or the general vicinity of the vessel. 
AEWC notes that MMOs are human and suffer from human flaws, and that 
observers are bad at judging distances in the water--i.e., whether a 
marine mammal is within the radii or not. AEWC further states that at 
night and during storms MMOs are particularly ineffective. Thus, AEWC 
concludes that Shell's proposed MMO program is not sufficient 
mitigation to prevent Shell from engaging in Level A harassment.
    Response: NMFS does not agree with AEWC's observation and 
conclusion, although AEWC is right that distance judging in the water 
is a challenging issue for MMOs. However, as noted in Shell's Marine 
Mammal Monitoring and Mitigation Plan (4MP), distances to nearby marine 
mammals will be estimated with binoculars (Fujinon 7 x 50) containing a 
reticle to measure the vertical angle of the line of sight to the 
animal relative to the horizon. In addition, MMOs may use a laser 
rangefinder to test and improve their abilities for visually estimating 
distances to objects in the water. The device was very useful in 
improving the distance estimation abilities of the observers at 
distances up to about 600 m (1,968 ft)--the maximum range at which the 
device could measure distances to highly reflective objects such as 
other vessels--while the isopleth to the 180 dB received level is 
expected to be at 125 m (410 ft) from the source vessel. Therefore, 
NMFS believes that marine mammal monitoring efforts that would be 
employed by Shell during its marine surveys are adequate.
    In addition, mitigation measures such as ramp-up of airguns would 
warn any marine mammals that are missed during the pre-survey period to 
leave the survey vicinity. Lastly, recent studies show that it is 
unlikely a marine

[[Page 49724]]

mammal would experience TTS when exposed to a seismic pulse at a 
received level of 190 dB (see Finneran et al. 2002). In order for a 
marine mammal to experience even a mild TTS, the animal has to be in a 
zone with intense noise for a certain duration to and be exposed to a 
sound level much greater than a single seismic impulse, and research on 
marine mammal behavior during TTS experiments indicates that animals 
will try to avoid areas where receive levels are high enough to cause 
TTS (see Finneran et al. 2002).
    Comment 27: NSB and AEWC note that Shell asserts that mitigation 
measures are designed to protect animals from injurious takes, but it 
is not clear that these mitigation measures are effective in protecting 
marine mammals or subsistence hunters. AEWC states that data previously 
presented by Shell and ConocoPhillips from their seismic activities 
made clear that MMOs failed to detect many marine mammals that 
encroached within the designated safety zones. AEWC further notes that 
Shell admits that night vision devices ``are not nearly as effective as 
visual observation during daylight hours.''
    Response: NMFS believes that the required monitoring and mitigation 
measures are effective and are an adequate means of effecting the least 
practicable impact to marine mammals and their habitat. Moreover, the 
safety zones for Shell's 2010 surveys are much smaller than those for 
the larger 3D seismic surveys in past years. The 180- and 190-dB safety 
zones are 125 m (410 ft) and 35 m (115 ft), respectively. The 
monitoring reports from 2006, 2007, 2008, and 2009 do not note any 
instances of serious injury or mortality (Patterson et al. 2007; Funk 
et al. 2008; Ireland et al. 2009; Reiser et al. 2010). Additionally, 
the fact that a power-down or shutdown is required does not indicate 
that marine mammals are not being detected or that they are incurring 
serious injury. As discussed elsewhere in this document and in the 
Notice of Proposed IHA (75 FR 27708; May 18, 2010), the received level 
of a single seismic pulse (with no frequency weighting) might need to 
be approximately 186 dB re 1 [mu]Pa\2\-s (i.e., 186 dB sound exposure 
level [SEL]) in order to produce brief, mild TTS (a non-injurious, 
Level B harassment) in odontocetes. Exposure to several strong seismic 
pulses that each have received levels near 175-180 dB SEL might result 
in slight TTS in a small odontocete, assuming the TTS threshold is (to 
a first approximation) a function of the total received pulse energy. 
For Shell's proposed survey activities, the distance at which the 
received energy level (per pulse) would be expected to be >=175-180 dB 
SEL is the distance to the 190 dB re 1 [mu]Pa (rms) isopleth (given 
that the rms level is approximately 10-15 dB higher than the SEL value 
for the same pulse). Seismic pulses with received energy levels >=175-
180 dB SEL (190 dB re 1 [mu]Pa (rms)) are expected to be restricted to 
a radius of approximately 35 m (115 ft) around the airgun array.
    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 background noise levels at 
those low frequencies tend to be higher. 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.
    In pinnipeds, TTS thresholds associated with exposure to brief 
pulses (single or multiple) of underwater sound have not been measured. 
Initial evidence from prolonged exposures suggested that some pinnipeds 
may incur TTS at somewhat lower received levels than do small 
odontocetes exposed for similar durations (Kastak et al. 1999; 2005). 
However, more recent indications are that TTS onset in the most 
sensitive pinniped species studied (harbor seal, which is closely 
related to the ringed seal) may occur at a similar SEL as in 
odontocetes (Kastak et al. 2004).
    NMFS concluded that cetaceans and pinnipeds should not be exposed 
to pulsed underwater noise at received levels exceeding, respectively, 
180 and 190 dB re 1 [mu]Pa (rms). The established 180- and 190-dB re 1 
[mu]Pa (rms) criteria are not considered to be the levels above which 
TTS might occur. Rather, they are the received levels above which, in 
the view of a panel of bioacoustics specialists convened by NMFS before 
TTS measurements for marine mammals started to become available, one 
could not be certain that there would be no injurious effects, auditory 
or otherwise, to marine mammals. As summarized above, data that are now 
available imply that TTS is unlikely to occur unless bow-riding 
odontocetes are exposed to airgun pulses much stronger than 180 dB re 1 
[mu]Pa rms (Southall et al. 2007). No cases of TTS are expected as a 
result of 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). PTS might occur at a received sound 
level at least several decibels above that inducing mild TTS if the 
animal is exposed to the strong sound pulses with very rapid rise time.
    It is highly unlikely that marine mammals could receive sounds 
strong enough (and over a sufficient duration) to cause permanent 
hearing impairment during a project employing the airgun sources 
planned here (i.e., an airgun array with a total discharge volume of 40 
in\3\). In the proposed project, marine mammals are unlikely to be 
exposed to received levels of seismic pulses strong enough to cause 
more than slight TTS. Given the higher level of sound necessary to 
cause PTS, it is even less likely that PTS could occur. In fact, even 
the levels immediately adjacent to the airgun may not be sufficient to 
induce PTS, especially because a mammal would not be exposed to more 
than one strong pulse unless it swam immediately alongside the airgun 
for a period longer than the inter-pulse interval. Baleen whales, and 
belugas as well, generally avoid the immediate area around operating 
seismic vessels. The planned monitoring and mitigation measures, 
including visual monitoring, power-downs, and shutdowns of the airguns 
when mammals are seen within the safety radii, will minimize the 
already-minimal probability of exposure of marine mammals to sounds 
strong enough to induce PTS.
    NMFS acknowledges that night-time monitoring by using night vision 
devices is not nearly as effective as visual observation during 
daylight hours. Therefore, the IHA to Shell prohibits start up of 
seismic airguns when the entire safety zone can not be effectively 
monitored during the night-time hours. If Shell has a shutdown of its 
seismic airgun array during low-light hours, it will have to wait till 
daylight to start ramping up the airguns.
    Comment 28: The Commission believes that absent an evaluation by 
the oil and gas industry of its monitoring and mitigation measures, the 
effects of the industry's activities will remain uncertain. The 
Commission recommends that NMFS require Shell to collect information 
necessary to evaluate the effectiveness of the

[[Page 49725]]

mitigation measures adopted and to review and modify mitigation 
measures accordingly. The Commission notes that mitigation measures 
required for Shell's proposed marine surveys should be useful to a 
degree, but in some cases they are not sufficiently specific. For 
example, the Commission raised questions about the ``power-down'' and 
asks NMFS to specify what speed of reduction would be required when a 
marine mammal is observed within 274 m (300 yards) of a vessel. The 
Commission considers it vital that NMFS and the industry make every 
reasonable effort to evaluate the mitigation measures whenever 
possible, and that the evaluation should provide a basis for (1) 
Distinguishing between measures that do and do not have protective 
value, (2) improving those that are useful, and (3) finding 
alternatives for those that are not. Citing a report from the Joint 
Subcommittee on Ocean Science and Technology, NSB also questions the 
effectiveness of ramp-up measures.
    Response: In order to issue an incidental take authorization (ITA) 
under Sections 101(a)(5)(A) and (D) of the MMPA, NMFS must, where 
applicable, set forth the permissible methods of taking pursuant to 
such activity, and other means of effecting the least practicable 
impact on such species or stock and its habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stock for 
taking for certain subsistence uses (where relevant). For Shell's 
proposed open water marine surveys, a series of mitigation and 
monitoring measures are required under the IHA. These mitigation 
measures include: (1) Sound source measurements to determine safety 
zones more accurately, (2) establishment of safety and disturbance 
zones to be monitored by MMOs on the seismic vessel, (3) a power-down 
when a marine mammal is detected approaching a safety zone and a 
shutdown when a marine mammal is observed within a zone, (4) ramp-up of 
the airgun array, (5) establishing a 120-dB safety zone and prohibition 
of seismic surveys within that zone whenever it encompasses four or 
more bowhead whale mother-calf pairs, (6) establishing a 160-dB safety 
zone that would prohibit firing of the seismic airguns within the zone 
whenever it encompasses 12 or more bowhead or gray whales involved in 
non-migratory behavior (e.g., feeding), and (7) a requirement that 
vessels reduce speed when within 274 m (300 yards) of whales and steer 
around those whales if possible.
    The basic rational for these mitigation measures is (a) To avoid 
exposing marine mammals to intense seismic airgun noises at received 
levels that could cause TTS (for mitigation measures listed as (1) 
through (4)), (b) to avoid exposing large aggregations of bowhead 
whales and bowhead whale calves to elevated noise received levels 
(mitigation measures (5) and (6)), and (c) to avoid vessel strike of 
marine mammals (mitigation measure (7)). Although limited research in 
recent years shows that noise levels that could induce TTS in 
odontocetes and pinnipeds are much higher than current NMFS safety 
thresholds (i.e., 180 dB and 190 dB re 1 [mu]Pa (rms) for cetaceans and 
pinnipeds, respectively), mitigation measures listed in (1) through (3) 
provide very conservative measures to ensure that no marine mammals are 
exposed to noise levels that would result in TTS. The power-down 
measure listed in (3) requires Shell to reduce the firing airguns 
accordingly so that a marine mammal that is detected approaching the 
safety zone will be further away from the reduced safety radius (as a 
result of power-down).
    Regarding mitigation measures requiring ramp-ups, while scientific 
research built around the question on whether ramp-up is effective has 
not been conducted, several studies on the effects of anthropogenic 
noise on marine mammals indicate that many marine mammals will move 
away from a sound source that they find annoying (e.g. Malme et al. 
1984; Miller et al. 1999; others reviewed in Richardson et al. 1995). 
In particular, three species of baleen whales have been the subject of 
tests involving exposure to sounds from a single airgun, which is 
equivalent to the first stage of ramp-up. All three species were shown 
to move away at the onset of a single airgun operation (Malme et al. 
1983; 1984; 1985; 1986; Richardson et al. 1986; McCauley et al. 1998; 
2000). From this research, it can be presumed that if a marine mammal 
finds a noise source annoying or disturbing, it will move away from the 
source prior to sustaining an injury, unless some other over-riding 
biological activity keeps the animal from vacating the area. This is 
the premise supporting NMFS' and others' belief that ramp-up is 
effective in preventing injury to marine mammals. However, to what 
degree ramp-up protects marine mammals from exposure to intense noises 
is unknown. Thus, NMFS will require industry applicants that will 
conduct marine or seismic surveys in the 2010 open water season to 
collect, record, analyze, and report MMO observations during any ramp-
up period, as recommended by the independent peer review panel convened 
in March 2010, to review Shell's monitoring plan (more information is 
available later in this document).
    Mitigation measures (5) and (6) regarding four cow-calf pairs and 
an aggregation of 12 bowhead and/or gray whales, which were proposed in 
MMS' 2006 programmatic EA and were required in NMFS IHAs issued between 
2006 to 2008, need to be further analyzed for their effectiveness and 
efficacy. NMFS is currently conducting a review of these mitigation 
measures through the Environmental Impact Statement process for the 
Arctic oil and gas activities.
    Finally, regarding the speed reduction for vessels in the vicinity 
of marine mammals, NMFS clarifies that vessel speed must be reduced to 
less than 10 knots when a marine mammal is detected within 274 m (300 
yards) of the vessel. This mitigation measure is to avoid vessel strike 
of marine mammals and is based on NMFS' ship strike rule for the north 
Atlantic right whale. NMFS will evaluate the efficacy of this 
mitigation. Although there has never been a vessel strike of marine 
mammals by vessels involved in seismic activities in the Arctic, NMFS 
is still taking this precaution.
    Comment 29: The Commission recommends that Shell be required to 
supplement its mitigation measures by using passive acoustic monitoring 
(PAM) to provide a more reliable estimate of the number of marine 
mammals taken during the course of the proposed seismic survey.
    Response: NMFS' 2010 EA for this action contains an analysis of why 
PAM is not required to be used by Shell to implement mitigation 
measures. Shell will deploy acoustic recorders to collect data on 
vocalizing animals. However, this information will not be used in a 
real-time or near-real-time capacity. Along with the fact that marine 
mammals may not always vocalize while near the PAM device, another 
impediment is that flow noise generated by a towed PAM will interfere 
with low frequency whale calls and make their detection difficult and 
unreliable. MMS sponsored a workshop on the means of acoustic detection 
of marine mammals in November 2009 in Boston, MA. The workshop reviewed 
various available acoustic monitoring technology (passive and active), 
its feasibility and applicability for use in MMS-authorized activities, 
and what additional developments need to take place to

[[Page 49726]]

improve its effectiveness. The conclusion is that at this stage, using 
towed passive acoustics to detect marine mammals is not a mature 
technology. NMFS may consider requirements for PAM in the future 
depending on information received as the technology develops further. 
Additionally, NMFS recommended to Shell that the company work to help 
develop and improve this type of technology for use in the Arctic.
    Comment 30: AWL states that NMFS should consider time and space 
limitations on surveying in order to reduce harm, and that there is a 
general consensus that spatial-temporal avoidance of high value habitat 
represents one of the best means to diminish potential impacts. In this 
case, AWL requests NMFS to evaluate the possibility of avoiding 
activities during the peak of the bowhead migration within the Beaufort 
migratory corridor before issuing an IHA. In addition, AWL requests 
NMFS to require Shell to complete its 30 days of shallow hazard 
surveying in July and August in an effort to avoid--as much as 
possible--the bulk of the bowhead migration.
    Response: In making its negligible determination for the issuance 
of an IHA to Shell for open water marine surveys, NMFS has conducted a 
thorough review and analysis on how to reduce any adverse effects to 
marine mammals from the proposed action, including the consideration of 
time and space limitations that could reduce impacts to the bowhead 
migration. As Shell indicates in its IHA application, the majority of 
the site clearance and shallow hazards surveys will be conducted during 
August and September to avoid the peak of the bowhead whale migration 
through the Beaufort Sea, which typically occurs in mid-September and 
October.
    In addition, bowhead whales migrating west across the Alaskan 
Beaufort Sea in autumn, in particular, are unusually responsive to 
airgun noises, with avoidance occurring out to distances of 20-30 km 
from a medium-sized airgun source (Miller et al. 1999; Richardson et 
al. 1999). However, while bowheads may avoid an area of 20 km (12.4 mi) 
around a noise source, when that determination requires a post-survey 
computer analysis to find that bowheads have made a 1 or 2 degree 
course change, NMFS believes that does not rise to a level of a 
``take'' and that such minor behavioral modification is not likely to 
be biologically significant.
    Comment 31: The Commission recommends that NMFS (1) Review the 
proposed monitoring measures to ensure that Shell is required to gather 
information on all the potentially important sources of noise and the 
complex sound field that the seismic survey activities create; (2) work 
with Shell and its contractors to engage acknowledged survey experts to 
review the survey design and planned analyses to ensure that Shell will 
provide relatively unbiased and reliable results; (3) work with Shell 
to coordinate a comparative analysis of the results of vessel-based, 
aerial, and passive acoustic monitoring methods to evaluate their 
relative strengths and weaknesses and determine if and how they could 
be improved for use with future surveys; (4) develop a plan for 
collecting meaningful baseline information--that is, information that 
provides a reliable basis for evaluating long-term effects on the 
marine mammal species and stocks that may be affected by oil and gas 
development and production in the Beaufort Sea area; and (5) work with 
Shell to determine how the data collected during the proposed 
activities can be made available to other scientific purposes.
    Response: NMFS largely agrees with the Commission's recommendations 
and has been working with the seismic survey applicants and their 
contractors on gathering information on acoustic sources, survey design 
review, and monitoring analyses. NMFS has contacted Shell and received 
information on all the active acoustic sources that would be used for 
its proposed open water marine surveys. The information includes source 
characteristics such as frequency ranges and source levels, as well as 
estimated propagation loss. In addition, at NMFS' request, Shell has 
provided power density spectra for all of its high-frequency sonar 
equipments.
    Regarding the remaining points, NMFS convened an independent peer 
review panel to review Shell's 4MP for the Open Water Marine Survey 
Program in the Beaufort and Chukchi Seas, Alaska. The panel met on 
March 25 and 26, 2010, and provided their final report to NMFS on April 
22, 2010. NMFS has reviewed the report and evaluated all 
recommendations made by the panel. NMFS has determined that there are 
several measures that Shell can incorporate into its 2010 open water 
Marine Survey Program 4MP to improve it, and is requiring those 
measures in the IHA. Additionally, there are other recommendations that 
NMFS has determined would also result in better data collection, and 
could potentially be implemented by oil and gas industry applicants, 
but which likely could not be implemented for the 2010 open-water 
season due to technical issues (see below). A detailed discussion about 
the panel review is presented later in this document. While it may not 
be possible to implement those changes this year, NMFS believes that 
they are worthwhile and appropriate suggestions that may require a bit 
more time to implement, and Shell should consider incorporating them 
into future monitoring plans should Shell decide to apply for IHAs in 
the future. Nevertheless, despite these recommendations, NMFS believes 
that Shell's 4MP will be sufficient for purposes of data gathering in 
2010.
    Comment 32: The Commission recommends that the IHA require Shell to 
halt its seismic survey and consult with NMFS regarding any seriously 
injured or dead marine mammal when the injury or death may have 
resulted from Shell's activities.
    Response: NMFS concurs with the Commission's recommendation. NMFS 
has included a condition in the IHA which requires Shell to immediately 
shutdown the seismic airguns if a dead or injured marine mammal has 
been sighted within an area where the seismic airguns were operating 
within the past 24 hours so that information regarding the animal can 
be collected and reported to NMFS. In addition, Shell must report the 
events to the Marine Mammal Stranding Network within 24 hours of the 
sighting, as well as to the NMFS staff person designated by the 
Director, Office of Protected Resources, or to the staff person 
designated by the Alaska Regional Administrator. The lead MMO is 
required to complete a written certification, which must include the 
following information: species or description of the animal(s); the 
condition of the animal(s) (including carcass condition if the animal 
is dead); location and time of first discovery; observed behaviors (if 
alive); and photographs or video (if available). In the event that the 
marine mammal injury or death was determined to have been a direct 
result of Shell's activities, then operations will cease, NMFS and the 
Stranding Network will be notified immediately, and operations will not 
be permitted to resume until NMFS has had an opportunity to review the 
written certification and any accompanying documentation, make 
determinations as to whether modifications to the activities are 
appropriate and necessary, and has notified Shell that activities may 
be resumed.
    If NMFS determines that further investigation is appropriate, once 
investigations are completed and determinations made, NMFS would use 
available information to help reduce the

[[Page 49727]]

likelihood that a similar event would happen in the future and move 
forward with necessary steps to ensure environmental compliance for oil 
and gas related activities under the MMPA.

Cumulative Impact Concerns

    Comment 33: NSB, AEWC, ICAS, and AWL state that NMFS must also 
consider the effects of disturbances in the context of other activities 
occurring in the Arctic. NSB states that NMFS should ascertain the 
significance of multiple exposures to underwater noise, ocean 
discharge, air pollution, and vessel traffic--all of which could impact 
bowhead whales and decrease survival rates or reproductive success. NSB 
notes that the cumulative impacts of all industrial activities must be 
factored into any negligible impact determination. NSB, AEWC, ICAS, and 
AWL list a series of reasonably foreseeable activities in the Arctic 
Ocean as: (1) GX Technology's Beaufort Sea seismic surveys; (2) 
Statoil's Chukchi Sea seismic surveys; (3) Seismic surveys planned in 
the Canadian Arctic; (4) U.S. Geological Survey's (USGS') seismic 
surveys; (5) BP's production operations at Northstar; and (6) 
Dalmorneftegeophysica (DMNG) Russian Far East offshore seismic surveys.
    Response: Under section 101(a)(5)(D) of the MMPA, NMFS is required 
to determine whether the taking by the applicant's specified activity 
will take only small numbers of marine mammals, will have a negligible 
impact on the affected marine mammal species or population stocks, and 
will not have an unmitigable impact on the availability of affected 
species or stocks for subsistence uses. Cumulative impact assessments 
are NMFS' responsibility under the National Environmental Policy Act 
(NEPA), not the MMPA. In that regard, MMS' 2006 Final PEA, NMFS' 2007 
and 2008 Supplemental EAs, NMFS' 2009 EA, and NMFS' 2010 EA address 
cumulative impacts. The most recent NMFS' 2010 EA addresses cumulative 
activities and the cumulative impact analysis focused on oil and gas 
related and non-oil and gas related activities in both Federal and 
State of Alaska waters that were likely and foreseeable. The oil and 
gas related activities in the U.S. Arctic in 2010 include this 
activity; Statoil's proposed seismic survey in Chukchi Sea; ION 
Geophysical's proposed seismic survey in Beaufort Sea; and BP's 
production operations at Northstar. GX Technology's Beaufort Sea 
seismic surveys have been cancelled by the company. Seismic survey 
activities in the Canadian and Russian Arctic occur in different 
geophysical areas, therefore, they are not analyzed under the NMFS 2010 
EA. Other appropriate factors, such as Arctic warming, military 
activities, and noise contributions from community and commercial 
activities were also considered in NMFS' 2010 EA. Please refer to that 
document for further discussion of cumulative impacts.
    Comment 34: Citing the peer review panel created for this year's 
open water meeting that Shell's activities ``will create a complex 
sound field with potential effects beyond those that the applicant 
proposes to monitor,'' and NRC's advice on assessing cumulative effects 
to the population from multiple effects to multiple individuals, the 
AWL recommends NMFS create a sound budget for the Arctic, limiting the 
total amount of sound introduced into the water. The AWL further states 
that instead of dismissing the impacts of relatively smaller sources of 
sound, NMFS should account for and regulate those sources, and a sound 
budget may be the most appropriate tool for doing so. The AWL states 
that even without a comprehensive sound budget, NMFS could impose 
limits on the total number of activities permitted in the Arctic during 
the open water season. Allowing only one or two noise generating 
activities each year could reduce the potential for take and would 
facilitate additional monitoring of the impacts of noise, since 
multiple noise sources make it very difficult to study the effect of 
specific sound sources.
    Response: NMFS agrees that assessing cumulative effects to the 
population from multiple effects to multiple individual marine mammals 
is an important approach to understanding overall impacts of industry 
activities to the species and the environment. NMFS is also considering 
the peer review panel's recommendation and is addressing sound budget 
issues in the marine environment through a series of workshops and a 
working group. In addition, Shell is required to provide sound source 
verification (SSV) tests before they start marine surveys. These 
acoustic measurements will be analyzed and provided in the 90-day 
report for Shell's marine surveys. Additional information on Arctic 
sound budget data are being collected by many researchers, including 
underwater recordings made by some of the passive acoustic arrays 
deployed on the Alaska north slope. These data will hopefully be 
analyzed to address overall ambient sound levels and a sound budget for 
the Arctic Ocean.
    Further, NMFS also requested that Shell provide source 
characteristics for all active acoustic sources that are planned to be 
used in the proposed open water marine surveys. NMFS has reviewed these 
data and analyzed overall ambient sound levels in the Arctic Ocean 
based on current knowledge. The review and analysis showed that the 
short-term ensonification of a small region in the Beaufort and Chukchi 
Seas during the open water season is not likely to appreciably increase 
the ambient noise level and alter the local ocean soundscape. A 
description of the analysis is provided in NMFS' 2010 EA for Shell and 
Statoil's proposed open water marine and seismic surveys (NMFS 2010).
    Finally, as NMFS is working on its Arctic EIS, limits on the total 
of oil and gas related activities to be allowed in the Arctic are being 
considered under separate alternatives. Nevertheless, NMFS does not 
agree with AWL's notion of ``[a]llowing only one or two noise 
generating activities each year'' as monitoring reports and studies 
from prior year industrial activities (e.g., there were five seismic 
survey activities in the open water season of 2008) indicate that 
multiple activities can be authorized in the Arctic while still 
reaching a finding of no significant impact, provided that appropriate 
mitigation and monitoring measures are prescribed and implemented.
    Comment 35: In addressing cumulative effects, Dr. Bain points out a 
number of ways he believes that Statoil's seismic surveys in the 
Chukchi Sea could interact with Shell's marine surveys: (1) If the same 
individuals are exposed to both projects, this would increase the 
duration of exposure beyond those considered in the applications. 
Further, individuals would potentially be exposed multiple times, and 
multiple exposures are likely to result in increased stress levels; (2) 
if both projects operate in the Chukchi at the same time, individuals 
would be forced to simultaneously respond to both noise sources. 
Avoidance of one noise source could result in a marine mammal 
approaching the other noise source, resulting in unexpectedly high 
noise exposure. This negates the safety assumption that animals will 
move away prior to receiving harmful exposure; and (3) different 
individuals may be exposed to the two projects, which would put NMFS' 
assumption that its policies only allow small takes to occur into 
question.
    Response: In assessing the cumulative effects, NMFS has considered 
that animals could be exposed to multiple activities, multiple times. 
As described in detail in the proposed IHA (75 FR

[[Page 49728]]

27708; May 18, 2010), Shell's ice gouge survey in the Chukchi Sea is 
not expected to result in takes of marine mammals due to its high 
frequency and the low energy acoustic sources being used. In addition, 
even if marine mammals would be affected by the presence of the ice 
gouge survey activities being conducted concurrently with Statoil's 3D 
marine seismic survey, the affected areas represent a small fraction of 
the total habitat of the Chukchi Sea, therefore, it is not likely that 
marine mammals avoiding one source would run into the other, as 
suggested by Dr. Bain. The ensonified area with received levels above 
160 dB in the Chukchi Sea is 531 km\2\ (or 0.089 percent of the entire 
Chukchi Sea). Finally, considering different individuals may be exposed 
to two projects in both the Beaufort and Chukchi Seas, NMFS has 
provided the total number of individuals that could be taken by Level B 
harassment from both activities and concludes that the total take 
numbers are small, with the most potential takes being: 184 Eastern 
Chukchi Sea beluga whales (4.95% of the population), 539 B-C-B bowhead 
whales (3.78% population), and 6,629 Alaska ringed seals (2.87% 
population). Potential takes of all other species are estimated to be 
under 1% of the populations. Therefore, NMFS believes Dr. Bain's 
concerns are not warranted.

ESA Concerns

    Comment 36: AWL states that NMFS section 7 consultation under the 
ESA must consider the potential impact of potential future oil and gas 
activities, including (1) Shell's strudel scour and ice gouge surveying 
to enable pipeline construction for production on its proposed Chukchi 
and Beaufort drill sites; and (2) a shallow hazard survey in Harrison 
Bay to allow for later exploration drilling. AWL states that in both 
instances, NMFS must consider the effects of the entire agency action.
    Response: Under section 7 of the ESA, NMFS Office of Protected 
Resources has completed consultation with NMFS Alaska Regional Office 
on ``Authorization of Small Takes under the Marine Mammal Protection 
Act for Certain Oil and Gas Exploration Activities in the U.S. Beaufort 
and Chukchi Seas, Alaska for 2010.'' In a Biological Opinion issued on 
July 13, 2010, NMFS concluded that the issuance of the incidental take 
authorizations under the MMPA for seismic surveys are not likely to 
jeopardize the continued existence of the endangered humpback or 
bowhead whale. As no critical habitat has been designated for these 
species, none will be affected. The 2010 Biological Opinion takes into 
consideration all oil and gas related seismic survey activities that 
would occur in the 2010 open water season. This Biological Opinion does 
not include impacts from exploratory drilling and production 
activities, which are subject to a separate consultation. In addition, 
potential future impacts from oil and gas activities will be subject to 
consultation in the future when activities are proposed. NMFS has 
reviewed Shell's proposed action and has determined that the findings 
in the 2010 Biological Opinion apply to its 2010 Beaufort Sea site 
clearance and shallow hazards surveys. In addition, NMFS has issued an 
Incidental Take Statement (ITS) under this Biological Opinion for 
Shell's survey activities, which contains reasonable and prudent 
measures with implementing terms and conditions to minimize the effects 
of take of bowhead and humpback whales.
    Comment 37: AWL argues that NMFS' existing regional biological 
opinion is inadequate. AWL states that NMFS' 2008 Biological Opinion 
does not adequately consider site-specific information related to 
Shell's proposed drilling. AWL points out that Shell has proposed 
exploration drilling in Camden Bay in the Beaufort Sea, and that Camden 
Bay has been repeatedly identified as a resting and feeding area for 
migrating bowheads, which has been reaffirmed by the recent monitoring. 
AWL states that NMFS should re-examine the potential impacts of Shell's 
proposed drilling in light of its long-standing policy and the 
cautionary language contained in its 2008 opinion.
    Response: NMFS initiated a section 7 consultation under the ESA for 
the potential impacts to ESA-listed marine mammal species that could be 
adversely affected as a result of several oil and gas related 
activities in the 2010 open-water season. The 2010 Biological Opinion 
covered the activities by Shell, Statoil, and ION's proposed open water 
marine and seismic survey activities. However, as far as Shell's 
drilling activities are concerned, Shell has withdrawn these actions 
due to the moratorium on offshore drilling.
    Comment 38: AWL argues that NMFS' 2008 Biological Opinion does not 
adequately consider oil spills. AWL states that in the 2008 Biological 
Opinion, NMFS recognized the potential dangers of a large oil spill, 
and that whales contacting oil, particularly freshly-spilled oil, 
``could be harmed and possibly killed.'' Citing NMFS's finding in its 
2008 Biological Opinion that several ``coincidental events'' would have 
to take place for such harm to occur: (1) A spill; (2) that coincides 
with the whales' seasonal presence; (3) that is ``transported to the 
area the whales occupy (e.g., the migrational corridor or spring lead 
system)''; and (4) is not successfully cleaned up. AWL points out that 
this combination of events is not as remote as NMFS appears to have 
assumed because NMFS' analysis of whether a spill may occur relies in 
part on statistical probabilities based on past incidents. AWL states 
that there appears to have been a significant breakdown in the system 
that was intended to both prevent spills from occurring and require 
adequate oil spill response capabilities to limit the harm. AWL states 
that NMFS must take into account that there are likely gaps in the 
current regulatory regime, and that given those flaws, an analysis that 
relies on the safety record of previous drilling is doubtful as a 
predictive tool.
    Response: As discussed in the previous Response to Comment, no 
drilling is planned for Shell during the 2010 open water season, 
therefore, these activities will be considered in a separate 
consultation if and when Shell proposes to conduct exploratory drilling 
because seismic activities do not raise an oil-spill concern.

NEPA Concerns

    Comment 39: AEWC believes that NMFS, in direct contravention of the 
law, excluded the public from the NEPA process since NMFS did not 
release a draft EA for the public to review and provide comments prior 
to NMFS taking its final action.
    Response: Neither NEPA nor the Council on Environmental Quality's 
(CEQ) regulations explicitly require circulation of a draft EA for 
public comment prior to finalizing the EA. The Federal courts have 
upheld this conclusion, and in one recent case, the Ninth Circuit 
squarely addressed the question of public involvement in the 
development of an EA. In Bering Strait Citizens for Responsible 
Resource Development v. U.S. Army Corps of Engineers (524 F.3d 938, 9th 
Cir. 2008), the court held that the circulation of a draft EA is not 
required in every case; rather, Federal agencies should strive to 
involve the public in the decision-making process by providing as much 
environmental information as is practicable prior to completion of the 
EA so that the public has a sufficient opportunity to weigh in on 
issues pertinent to the agency's decision-making process. In the case 
of Shell's 2010 MMPA IHA request, NMFS involved the public in the 
decision-making process by distributing Shell's IHA application and 
addenda for a 30-

[[Page 49729]]

day notice and comment period. However, at that time, a draft EA was 
not available to provide to the public for comment. The IHA application 
and NMFS' Notice of Proposed IHA (75 FR 27708; May 18, 2010) contained 
information relating to the project. For example, the application 
included a project description, its location, environmental matters 
such as species and habitat to be affected, and measures designed to 
minimize adverse impacts to the environment and the availability of 
affected species or stocks for subsistence uses.
    Comment 40: AEWC notes that Shell's IHA application warrants review 
in an environmental impact statement (EIS) given the potential for 
significant impacts.
    Response: NMFS' 2010 EA was prepared to evaluate whether 
significant environmental impacts may result from the issuance of an 
IHA to Shell, which is an appropriate application of NEPA. After 
completing the EA, NMFS determined that there would not be significant 
impacts to the human environment and accordingly issued a FONSI. 
Therefore, an EIS is not needed for this action.
    Comment 41: AEWC, AWL, and NSB note that NMFS is preparing a 
Programmatic EIS (PEIS). Although MMS published a draft PEIS (PEIS; MMS 
2007) in the summer of 2007, to date, a Final PEIS has not been 
completed. AWL also notes that NMFS and MMS have reaffirmed their 
previous determination that a programmatic EIS process is necessary to 
address the overall, cumulative impacts of increased oil and gas 
activity in the Arctic Ocean and intend to incorporate into that 
analysis new scientific information as well as new information about 
projected seismic and exploratory drilling activity in both seas. 
However, AWL and AEWC argue that NEPA regulations make clear that NMFS 
should not proceed with authorizations for individual projects like 
Shell's surveying until its programmatic EIS is complete. NSB states 
that it would be regretful for Shell to proceed on a one-year IHA when 
the impact of those activities could have a catastrophic impact on 
Arctic resources and foreclose management options to be developed in 
the forthcoming EIS.
    Response: While the Final PEIS will analyze the affected 
environment and environmental consequences from seismic surveys in the 
Arctic, the analysis contained in the Final PEIS will apply more 
broadly to Arctic oil and gas operations. NMFS' issuance of an IHA to 
Shell for the taking of several species of marine mammals incidental to 
conducting its open-water marine survey program in the Chukchi and 
Beaufort Seas in 2010, as analyzed in the EA, is not expected to 
significantly affect the quality of the human environment. Shell's 
surveys are not expected to significantly affect the quality of the 
human environment because of the limited duration and scope of Shell's 
operations. Additionally, the EA contained a full analysis of 
cumulative impacts.

Miscellaneous Issues

    Comment 42: The AEWC states that Shell was unable to reach an 
accord on the annual CAA with AEWC. AEWC states that the CAA has 
historically formed the basis for NMFS' statutorily required 
determination of no unmitigable adverse impacts to subsistence 
activities. Specifically, AEWC states that Shell was not able to reach 
agreement with AEWC on (1) provisions for zero discharge and (2) on the 
sound threshold for activities that should be subject to sound source 
verification procedures. AEWC requests NMFS to fulfill its 
Congressional mandate and ensure that Shell's activities do not have 
more than a negligible impact on marine mammal stocks or an unmitigable 
adverse impact on the subsistence activities. The Commission also 
recommends that NMFS require Shell to engage in consultations with 
Alaska Native communities that may be affected by the company's 
activities and, to the extent feasible, seek to resolve any Alaska 
Native concerns through negotiation of a CAA.
    Response: AEWC states that the CAA has historically formed the 
basis for NMFS' statutorily required determination of no unmitigable 
adverse impacts to subsistence activities, which is incorrect. Under 
sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.), an 
IHA or LOA shall be granted to U.S. citizens who engage in a specified 
activity (other than commercial fishing) within a specified 
geographical region if NMFS finds that the taking of marine mammals 
will have a negligible impact on the species or stock(s) and will not 
have an unmitigable adverse impact on the availability of the species 
or stock(s) for certain subsistence uses, and if the permissible 
methods of taking and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth. In other words, 
no marine mammal take authorizations may be issued if NMFS has reason 
to believe that the proposed exploration or development activities 
would have an unmitigable adverse impact on the availability of marine 
mammal species or stock(s) for Alaskan native subsistence uses. 
Although Federal laws do not require consultation with the native 
coastal communities until after offshore exploration and development 
plans have been finalized, permitted, and authorized, pre-permitting 
consultations between the oil and gas industry and the Alaskan coastal 
native communities are considered by NMFS when the agency makes a 
determination whether such activities would have an unmitigable adverse 
impact on the availability of marine mammal species or stock(s) for 
subsistence uses. For the proposed marine surveys, Shell has conducted 
POC meetings for its seismic operations in the Beaufort and Chukchi 
Seas in the communities and villages of Nuiqsut, Kaktovik, Barrow, 
Kotzebue, Wainwright, Point Lay, and Point Hope.
    Shell has not signed the 2010 CAA with Alaska Natives and has 
informed NMFS that it does not intend to do so. NMFS has scrutinized 
all of the documents submitted by Shell (e.g., IHA application, Plan of 
Cooperation and other correspondence to NMFS and affected stakeholders) 
and documents submitted by other affected stakeholders and concluded 
that harassment of marine mammals incidental to Shell's activities will 
not have more than a negligible impact on marine mammal stocks or an 
unmitigable adverse impact on the availability of marine mammals for 
taking for subsistence uses. This finding was based in large part on 
NMFS' definition of ``negligible impact,'' ``unmitigable adverse 
impact,'' the proposed mitigation and monitoring measures, the scope of 
activities proposed to be conducted, including time of year, location 
and presence of marine mammals in the project area, and Shell's Plan of 
Cooperation.
    As described in Shell's IHA application, 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

[[Page 49730]]

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 to 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 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; 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.
    Besides bowhead whale hunting, beluga whales are hunted for 
subsistence at Barrow, Wainwright, Point Lay, and Point Hope, with the 
most taken by Point Lay (Fuller and George 1997). Harvest at all of 
these villages generally occurs between April and July with most taken 
in April and May when pack-ice conditions deteriorate and leads open 
up. Ringed, bearded, and spotted seals are hunted by all of the 
villages bordering the project area (Fuller and George 1997). Ringed 
and bearded seals are hunted throughout the year, but most are taken in 
May, June, and July when ice breaks up and there is open water instead 
of the more difficult hunting of seals at holes and lairs. Spotted 
seals are only hunted in spring through summer.
    Therefore, the scheduling of the proposed marine surveys is 
expected to have minimum conflict between the industries and marine 
mammal harvests.
    Finally, the required mitigation and monitoring measures are 
expected to reduce any adverse impacts on marine mammals for taking for 
subsistence uses to the extent practicable. These measures include, but 
are not limited to, the 180 dB and 190 dB safety (shut-down/power-down) 
zones; a requirement to monitor the 160 dB isopleths for aggregations 
of 12 or more non-migratory balaenidae whales and when necessary shut 
down seismic airguns; reducing vessel speed to 10 knots or less when a 
vessel is within 300 yards of whales to avoid a collision; utilizing 
communication centers to avoid any conflict with subsistence hunting 
activities; and the use of marine mammal observers.
    Measures related to ``zero volume discharge'' do not affect NMFS' 
negligible determination on impacts of the species or stock(s) or the 
unmitigable adverse impact determination on the availability of the 
species or stock(s) for certain subsistence uses, as long as Shell's 
emission discharge is within the guidelines set by the Environmental 
Protection Agency (EPA). Regarding the sound source verification (SSV), 
NMFS requires Shell to conduct SSV tests for all its airgun and active 
acoustic sources and seismic and support vessels that will be involved 
in the proposed marine surveys.
    Over the past several months, NMFS has worked with both Alaska 
Native communities and the industry, to the extent feasible, to resolve 
any Alaska Native concerns from the proposed open water marine and 
seismic surveys. These efforts include convening an open water 
stakeholders' meeting in Anchorage, AK, in March 2010, and multiple 
conference meetings with representatives of the Alaska Native 
communities and the industry. Lastly, as mentioned previously in this 
document, NMFS has included several measures from the CAA in the IHA 
issued to Shell.
    Comment 43: AEWC notes that, in 2009, NMFS did not publish its 
response to comments on proposed IHAs activities conducted during the 
open water season until well after the fall subsistence hunt at Cross 
Island had concluded and geophysical operations had already taken 
place. AEWC states that NMFS' failure to release its response to 
comments until after the activities had taken place casts serious doubt 
on the validity of NMFS' public involvement process and the underlying 
analysis of impacts to subsistence activities and marine mammals.
    Response: NMFS does not agree with AEWC's statement that NMFS' 
failure to release its response to comments until after the activities 
had taken place casts doubt on the validity of NMFS' public involvement 
process, or the underlying analysis of impacts to subsistence 
activities and marine mammals. As stated earlier, the decision to issue 
an IHA to Shell for its proposed marine surveys in the Beaufort and 
Chukchi Seas is based in large part on NMFS' definition of ``negligible 
impact,'' ``unmitigable adverse impact,'' the proposed mitigation and 
monitoring measures, the scope of activities proposed to be conducted, 
including time of year, location and presence of marine mammals in the 
project area, extensive research and studies on potential impacts of 
anthropogenic sounds to marine mammals, marine mammal behavior, 
distribution, and movements in the vicinity of Shell's proposed project 
areas, Shell's Plan of Cooperation, and on public comments received 
during the commenting period and peer-review recommendations by an 
independent review panel. The reason that NMFS was not able to publish 
its response to comments on proposed IHA activities in 2009 for Shell's 
shallow hazards and site clearance surveys until the end of the survey 
activities was due to the large amount of comments NMFS received. NMFS 
was able to review and analyze all comments it received and address 
their validity for the issuance of the IHA. However, due to the large 
volume of comments, NMFS was not able to organize them into publishable 
format to be incorporated into the Federal Register notice for 
publication on a timely basis. NMFS will strive to make sure that all 
comments are addressed in full and published by the time IHAs or LOAs 
are issued.
    Comment 44: AEWC states that Shell failed to provide plans for 
community engagement. AEWC states that Shell is required to include in 
its application a ``schedule for meeting with affected subsistence 
communities to discuss proposed activities and to resolve potential 
conflicts regarding any aspects of either the operation or the plan of 
cooperation.'' (50 CFR 216.104(a)(12)(ii)). However, AEWC notes that in 
its application, Shell only just mentions that it held a few meetings 
and ``anticipates continued engagement.'' AEWC argues that this vague 
intention to participate in more meetings with the affected communities 
is insufficient and does not satisfy the regulatory requirement. AEWC 
points out that Shell is also required to provide its plans for 
continuing to meet with communities. AEWC notes that while Shell 
mentions communicating with communities via its SA and Com and

[[Page 49731]]

Call Center program, which allows for the availability of back and 
forth communication, the company has described no actual, planned 
communication with the affected communities.
    Response: The information AEWC contained in the comment is 
outdated. Since the submission of Shell's IHA application, Shell 
indicated that it completed its pre-season Plan of Cooperation meetings 
for the 2010 season in early April 2010. Through the Subsistence 
Advisor (SA) and Com and Call Center (Com Center) program for 2010, 
Shell's SA and Shell representatives in the Com Centers will be 
available daily to the communities throughout the 2010 season. The SA 
and Com Center programs provide residents of the nearest affected 
communities a way to communicate where and when subsistence activities 
occur so that industry may avoid conflicts with planned subsistence 
activities.
    Comment 45: NSB states that NMFS should consider and address 
disproportionate impacts in analyzing the IHA application, that Federal 
agencies must ``make achieving environmental justice part of * * * 
[their] mission[s].'' Compared to many United States residents, NSB 
states that Alaskan Natives face significant impacts from oil and gas 
activities in the OCS. NSB requests that NMFS thus specifically address 
issues of environmental justice in considering this application and 
that NMFS must also work to ensure effective public participation and 
access to information, and must ``ensure that public documents, 
notices, and hearings relating to human health or the environment are 
concise, understandable, and readily accessible to the public.''
    Response: Under section 101(a)(5)(D) of the MMPA, NMFS is required 
to determine whether the taking by the applicant's specified activity 
will take only small numbers of marine mammals, will have a negligible 
impact on the affected marine mammal species or population stocks, and 
will not have an unmitigable impact on the availability of affected 
species or stocks for subsistence uses. Environmental justice and other 
impacts to the human environment are NMFS' responsibility under the 
NEPA and applicable executive orders, not the MMPA. In that regard, 
NMFS' 2010 EA addresses the potential cumulative impacts to the 
socioeconomic environment, including traditional knowledge, community 
and economy of the Alaskan Arctic, subsistence harvesting, and coastal 
and marine use issues. Please refer to NMFS' 2010 EA for these 
assessments.
    In addition, NMFS has been working with the public to ensure public 
participation, which includes the public review and comments on Shell's 
IHA application and the proposed IHA. All documents related to this 
action are available through the NMFS Office of Protected Resources Web 
site at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.

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) throughout 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 Beaufort Sea 
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 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.

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,

[[Page 49732]]

schedule a workshop to review the plan'' (50 CFR 216.108(d)).
    NMFS convened an independent peer review panel to review Shell's 
Marine Mammal Monitoring and Mitigation Plan (4MP) for the Open Water 
Marine Survey Program in the Beaufort and Chukchi Seas, Alaska, during 
2010. The panel met on March 25 and 26, 2010, and provided their final 
report to NMFS on April 22, 2010. The full panel report can be viewed 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    NMFS provided the panel with Shell's 4MP and asked the panel to 
address the following questions and issues for Shell's plan:
    (1) The monitoring program should document the effects (including 
acoustic) on marine mammals and document or estimate the actual level 
of take as a result of the activity. Does the monitoring plan meet this 
goal?
    (2) Ensure that the monitoring activities and methods described in 
the plan will enable the applicant to meet the requirements listed in 
(1) above;
    (3) Are the applicant's objectives achievable based on the methods 
described in the plan?
    (4) Are the applicant's objectives the most useful for 
understanding impacts on marine mammals?
    (5) Should the applicant consider additional monitoring methods or 
modifications of proposed monitoring methods for the proposed activity? 
And
    (6) What is the best way for an applicant to report their data and 
results to NMFS?
    Section 3 of the report contains recommendations that the panel 
members felt were applicable to all of the monitoring plans reviewed 
this year. Section 4.4 of the report contains recommendations specific 
to Shell's Open Water Marine Survey Program 4MP. Specifically, for the 
general recommendations, the panel commented on issues related to: (1) 
Acoustic effects of oil and gas exploration--assessment and mitigation; 
(2) aerial surveys; (3) MMOs; (4) visual near-field monitoring; (5) 
visual far-field monitoring; (6) baseline biological and environmental 
information; (7) comprehensive ecosystem assessments and cumulative 
impacts; (8) duplication of seismic survey effort; and (9) whale 
behavior.
    NMFS has reviewed the report and evaluated all recommendations made 
by the panel. NMFS has determined that there are several measures that 
Shell can incorporate into its 2010 Open Water Marine Survey Program 
4MP to improve it. Additionally, there are other recommendations that 
NMFS has determined would also result in better data collection, and 
could potentially be implemented by oil and gas industry applicants, 
but which likely could not be implemented for the 2010 open water 
season due to technical issues (see below). While it may not be 
possible to implement those changes this year, NMFS believes that they 
are worthwhile and appropriate suggestions that may require a bit more 
time to implement, and Shell should consider incorporating them into 
future monitoring plans should Shell decide to apply for IHAs in the 
future.
    The following subsections lay out measures that NMFS recommends for 
implementation as part of the 2010 Open Water Marine Survey Program 4MP 
and those that are recommended for future programs.

Recommendations for Inclusion in the 2010 4MP and IHA

    Section 3.3 of the panel report contains several recommendations 
regarding MMOs, which NMFS agrees that Shell should incorporate:
     Observers should be trained using visual aids (e.g., 
videos, photos), to help them identify the species that they are likely 
to encounter in the conditions under which the animals will likely be 
seen.
     Observers should understand the importance of classifying 
marine mammals as ``unknown'' or ``unidentified'' if they cannot 
identify the animals to species with confidence. In those cases, they 
should note any information that might aid in the identification of the 
marine mammal sighted. For example, for an unidentified mysticete 
whale, the observers should record whether the animal had a dorsal fin.
     Observers should attempt to maximize the time spent 
looking at the water and guarding the safety radii. They should avoid 
the tendency to spend too much time evaluating animal behavior or 
entering data on forms, both of which detract from their primary 
purpose of monitoring the safety zone.
     `Big eye' binoculars (25 x 150) should be used from high 
perches on large, stable platforms. They are most useful for monitoring 
impact zones that extend beyond the effective line of sight. With two 
or three observers on watch, the use of `big eyes' should be paired 
with searching by naked eye, the latter allowing visual coverage of 
nearby areas to detect marine mammals. When a single observer is on 
duty, the observer should follow a regular schedule of shifting between 
searching by naked-eye, low-power binoculars, and big-eye binoculars 
based on the activity, the environmental conditions, and the marine 
mammals of concern.
     Observers should use the best possible positions for 
observing (e.g., outside and as high on the vessel as possible), taking 
into account weather and other working conditions.
     Whenever possible, new observers should be paired with 
experienced observers to avoid situations where lack of experience 
impairs the quality of observations. If there are Alaska Native MMOs, 
the MMO training that is conducted prior to the start of the survey 
activities should be conducted with both Alaska Native MMOs and 
biologist MMOs being trained at the same time in the same room. There 
should not be separate training courses for the different MMOs.
    In Section 3.4, panelists recommend collecting some additional data 
to help verify the utility of the ``ramp-up'' requirement commonly 
contained in IHAs. To help evaluate the utility of ramp-up procedures, 
NMFS will require observers to record and report their observations 
during any ramp-up period. An analysis of these observations may lead 
to the conclusion regarding the effectiveness of ramp-up and should be 
included in the monitoring report.
    Among other things, Section 3.5 of the panel report recommends 
recording visibility data because of the concern that the line-of-sight 
distance for observing marine mammals is reduced under certain 
conditions. MMOs should ``carefully document visibility during 
observation periods so that total estimates of take can be corrected 
accordingly''.
    Section 4.4 of the report contains recommendations specific to 
Shell's Open Water Marine Survey Program 4MP. Of the recommendations 
presented in this section, NMFS has determined that the following 
should be implemented for the 2010 season:
     Summarize observation effort and conditions, the number of 
animals seen by species, the location and time of each sighting, 
position relative to the survey vessel, the company's activity at the 
time, each animal's response, and any adjustments made to operating 
procedures. Provide all spatial data on charts (always including vessel 
location).
     Make all data available in the report or (preferably) 
electronically for integration with data from other companies.
     Accommodate specific requests for raw data, including 
tracks of all vessels and aircraft associated with the operation and 
activity logs documenting when and what types of sounds are

[[Page 49733]]

introduced into the environment by the operation.
    NMFS spoke with Shell about the inclusion of these recommendations 
into the 2010 4MP and IHA. Shell indicated to NMFS that they will 
incorporate these recommendations into the 4MP, and NMFS has made 
several of these recommendations requirements in the IHA.

Recommendations for Inclusion in Future Monitoring Plans

    Section 3.5 of the report recommends methods for conducting 
comprehensive monitoring of a large-scale seismic operation. One method 
for conducting this monitoring recommended by panel members is the use 
of passive acoustic devices. Additionally, Section 3.2 of the report 
encourages the use of such systems if aerial surveys will not be used 
for real-time mitigation monitoring. NMFS acknowledges that there are 
challenges involved in using this technology to detect bowhead whale 
vocalizations in conjunction with seismic airguns in this environment, 
especially in real time. However, NMFS recommends that Shell work to 
help develop and improve this type of technology for use in the Arctic 
(and use it once it is available and effective), as it could be 
valuable both for real-time mitigation implementation, as well as 
archival data collection. Shell indicated to NMFS that they have been 
working for several years to aid in the development of such technology 
and will continue to do so.
    The panelists also recommend adding a tagging component to 
monitoring plans. ``Tagging of animals expected to be in the area where 
the survey is planned also may provide valuable information on the 
location of potentially affected animals and their behavioral responses 
to industrial activities. Although the panel recognized that such 
comprehensive monitoring might be difficult and expensive, such an 
effort (or set of efforts) reflects the complex nature of the challenge 
of conducting reliable, comprehensive monitoring for seismic or other 
relatively-intense industrial operations that ensonify large areas of 
ocean.'' While this particular recommendation is not feasible for 
implementation in 2010, NMFS recommends that Shell consider adding a 
tagging component to future seismic survey monitoring plans should 
Shell decide to conduct such activities in future years. Shell 
currently helps to fund the U.S. Geological Survey's walrus tagging 
project in the Arctic and is open to the idea of helping to fund other 
marine mammal tagging projects in the Arctic.
    To the extent possible, NMFS recommends implementing the 
recommendation contained in Section 4.4.6 for the 2010 season: 
``Integrate all observer data with information from tagging and 
acoustic studies to provide a more comprehensive description of the 
acoustic environment during its survey.'' However, NMFS recognizes that 
this integration process may take time to implement. Therefore, Shell 
should begin considering methods for the integration of the observer 
data now if Shell intends to apply for IHAs in the future.
    In Section 3.4, panelists recommend collecting data to evaluate the 
efficacy of using forward-looking infrared devices (FLIR) vs. night-
vision binoculars. The panelists note that while both of these devices 
may increase detection capabilities by MMOs of marine mammals, the 
reliability of these technologies should be tested under appropriate 
conditions and their efficacy evaluated. NMFS recommends that Shell 
design a study to explore using both FLIR and night-vision binoculars 
and collect data on levels of detection of marine mammals using each 
type of device.

Other Recommendations in the Report

    The panel also made several recommendations, which are not 
discussed in the two preceding subsections. NMFS determined that many 
of the recommendations were made beyond the bounds of what the panel 
members were tasked to do. For example, the panel recommended that NMFS 
begin a transition away from using a single metric of acoustic exposure 
to estimate the potential effects of anthropogenic sound on marine 
living resources. This is not a recommendation about monitoring but 
rather addresses a NMFS policy issue. NMFS is currently in the process 
of revising its acoustic guidelines on a national scale. A 
recommendation was also made regarding the training and oversight of 
MMOs. NMFS is currently working on a national policy for this as well 
Section 3.7 of the report contains several recommendations regarding 
comprehensive ecosystem assessments and cumulative impacts. These are 
good, broad recommendations, however, the implementation of these 
recommendations would not be the responsibility solely of oil and gas 
industry applicants. The recommendations require the cooperation and 
input of several groups, including Federal, state, and local government 
agencies, members of other industries, and members of the scientific 
research community. NMFS will encourage the industry and others to 
build the relationships and infrastructure necessary to pursue these 
goals, and incorporate these recommendations into future MMPA 
authorizations, as appropriate. Lastly, Section 3.8 of the report makes 
a recommendation regarding data sharing and reducing the duplication of 
seismic survey effort. While this is a valid recommendation, it does 
not relate to monitoring or address any of the six questions with which 
the panel members were tasked to answer.
    For some of the recommendations, NMFS felt that additional 
clarification was required by the panel members before NMFS could 
determine whether or not applicants should incorporate them into the 
monitoring plans. Section 3.2 of the report discusses the use of and 
methods for conducting aerial surveys. Industry applicants have not 
conducted aerial surveys in Chukchi Sea lease sale areas for several 
years because of the increased risk for flying there (as noted by the 
panel report). To that end, NMFS has asked the panel to provide 
recommendations on whether or not similar surveys could be conducted 
from dedicated vessel-based platforms. NMFS also asked for additional 
clarification on some of the recommendations regarding data collection 
and take estimate calculations. In addition, NMFS asked the panel 
members for clarification on the recommendation contained in Section 
3.6 regarding baseline studies. Lastly, NMFS asked the panel members 
for clarification on the recommendation specific to Shell contained in 
Section 4.4 regarding estimating statistical power for all methods 
intended to detect adverse impacts. Once NMFS hears back from the panel 
and is clear with these recommendations, NMFS will follow up with Shell 
and discuss the implementation of these additional measures in future 
years.

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 and Sonar 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

[[Page 49734]]

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.
    Mysticete: Baleen whales generally tend to avoid operating airguns, 
but avoidance radii are quite variable. Whales are often reported to 
show no overt reactions to airgun pulses at distances beyond a few 
kilometers, even though the airgun pulses remain well above ambient 
noise levels out to much longer distances (reviewed in Richardson et 
al. 1995; Gordon et al. 2004). However, studies done since the late 
1990s of migrating humpback and migrating bowhead whales show 
reactions, including avoidance, that sometimes extend to greater 
distances than documented earlier. Avoidance distances often exceed the 
distances at which boat-based observers can see whales, so observations 
from the source vessel can be biased. Observations over broader areas 
may be needed to determine the range of potential effects of some 
large-source seismic surveys where effects on cetaceans may extend to 
considerable distances (Richardson et al. 1999; Moore and Angliss 
2006). Longer-range observations, when required, can sometimes be 
obtained via systematic aerial surveys or aircraft-based observations 
of behavior (e.g., Richardson et al. 1986, 1999; Miller et al. 1999, 
2005; Yazvenko et al. 2007a, 2007b) or by use of observers on one or 
more support vessels operating in coordination with the seismic vessel 
(e.g., Smultea et al. 2004; Johnson et al. 2007). However, the presence 
of other vessels near the source vessel can, at least at times, reduce 
sightability of cetaceans from the source vessel (Beland et al. 2009), 
thus complicating interpretation of sighting data.
    Some baleen whales show considerable tolerance of seismic pulses. 
However, when the pulses are strong enough, avoidance or other 
behavioral changes become evident. Because the responses become less 
obvious with diminishing received sound level, it has been difficult to 
determine the maximum distance (or minimum received sound level) at 
which reactions to seismic become evident and, hence, how many whales 
are affected.
    Studies of gray, bowhead, and humpback whales have determined that 
received levels of pulses in the 160-170 dB re 1 [mu]Pa (rms) range 
seem to cause obvious avoidance behavior in a substantial fraction of 
the animals exposed (see review in Southall et al. 2007). In many 
areas, seismic pulses diminish to these levels at distances ranging 
from 4-15 km from the source. A substantial proportion of the baleen 
whales within such distances may show avoidance or other strong 
disturbance reactions to the operating airgun array. However, in other 
situations, various mysticetes tolerate exposure to full-scale airgun 
arrays operating at even closer distances, with only localized 
avoidance and minor changes in activities. At the other extreme, in 
migrating bowhead whales, avoidance often extends to considerably 
larger distances (20-30 km) and lower received sound levels (120-130 dB 
re 1 [mu]Pa (rms)). Also, even in cases where there is no conspicuous 
avoidance or change in activity upon exposure to sound pulses from 
distant seismic operations, there are sometimes subtle changes in 
behavior (e.g., surfacing-respiration-dive cycles) that are only 
evident through detailed statistical analysis (e.g., Richardson et al. 
1986; Gailey et al. 2007).
    Data on short-term reactions by cetaceans to impulsive noises are 
not necessarily indicative of long-term or biologically significant 
effects. It is not known whether impulsive sounds affect reproductive 
rate or distribution and habitat use in subsequent days or years. 
However, gray whales have continued to migrate annually along the west 
coast of North America despite intermittent seismic exploration (and 
much ship traffic) in that area for decades (Appendix A in Malme et al. 
1984; Richardson et al. 1995), and there has been a substantial 
increase in the population over recent decades (Allen and Angliss 
2010). The western Pacific gray whale population did not seem affected 
by a seismic survey in its feeding ground during a prior year (Johnson 
et al. 2007). Similarly, bowhead whales have continued to travel to the 
eastern Beaufort Sea each summer despite seismic exploration in their 
summer and autumn range for many years (Richardson et al. 1987), and 
their numbers have increased

[[Page 49735]]

notably (Allen and Angliss 2010). Bowheads also have been observed over 
periods of days or weeks in areas ensonified repeatedly by seismic 
pulses (Richardson et al. 1987; Harris et al. 2007). However, it is 
generally not known whether the same individual bowheads were involved 
in these repeated observations (within and between years) in strongly 
ensonified areas. In any event, in the absence of some unusual 
circumstances, the history of coexistence between seismic surveys and 
baleen whales suggests that brief exposures to sound pulses from any 
single seismic survey are unlikely to result in prolonged effects.
    Odontocete: Little systematic information is available about 
reactions of toothed whales to airgun pulses. Few studies similar to 
the more extensive baleen whale/seismic pulse work summarized above 
have been reported for toothed whales. However, there are recent 
systematic data on sperm whales (e.g., Gordon et al. 2006; Madsen et 
al. 2006; Winsor and Mate 2006; Jochens et al. 2008; Miller et al. 
2009). There is also an increasing amount of information about 
responses of various odontocetes to seismic surveys based on monitoring 
studies (e.g., Stone 2003; Smultea et al. 2004; Moulton and Miller 
2005; Bain and Williams 2006; Holst et al. 2006; Stone and Tasker 2006; 
Potter et al. 2007; Hauser et al. 2008; Holst and Smultea 2008; Weir 
2008; Barkaszi et al. 2009; Richardson et al. 2009).
    Dolphins and porpoises are often seen by observers on active 
seismic vessels, occasionally at close distances (e.g., bow riding). 
However, some studies near the U.K., Newfoundland and Angola, in the 
Gulf of Mexico, and off Central America have shown localized avoidance. 
Also, belugas summering in the Canadian Beaufort Sea showed larger-
scale avoidance, tending to avoid waters out to 10-20 km from operating 
seismic vessels. In contrast, recent studies show little evidence of 
conspicuous reactions by sperm whales to airgun pulses, contrary to 
earlier indications.
    There are almost no specific data on responses of beaked whales to 
seismic surveys, but it is likely that most if not all species show 
strong avoidance. There is increasing evidence that some beaked whales 
may strand after exposure to strong noise from tactical military mid-
frequency sonars. Whether they ever do so in response to seismic survey 
noise is unknown. Northern bottlenose whales seem to continue to call 
when exposed to pulses from distant seismic vessels.
    For delphinids, and possibly the Dall's porpoise, the available 
data suggest that a >=170 dB re 1 [mu]Pa (rms) disturbance criterion 
(rather than >=160 dB) would be appropriate. With a medium-to-large 
airgun array, received levels typically diminish to 170 dB within 1-4 
km, whereas levels typically remain above 160 dB out to 4-15 km (e.g., 
Tolstoy et al. 2009). Reaction distances for delphinids are more 
consistent with the typical 170 dB re 1 [mu]Parms distances.
    Due to their relatively higher frequency hearing ranges when 
compared to mysticetes, odontocetes may have stronger responses to mid- 
and high-frequency sources such as sub-bottom profilers, side scan 
sonar, and echo sounders than mysticetes (Richardson et al. 1995; 
Southall et al. 2007). Although the mid- and high-frequency active 
acoustic sources with operating frequency between 2 and 50 kHz planned 
to be used by Shell have much lower power outputs (167-200 dB re 1 
[mu]Pa @ 1 m at source level) than those from the airguns, they could 
cause mild behavior reactions to odontocete whales because their 
operating frequencies fall within the sensitive hearing range of these 
animals. However, scientific information is lacking on specific 
behavioral responses by odontocetes to mid- and high-frequency sources. 
Nevertheless, based on our current knowledge on mysticete reaction 
towards low-frequency airgun pulses, we could induce that more or less 
similar reactions could be exhibited by odontocete whales towards mid- 
and high-frequency sources.
    Pinnipeds: Few studies of the reactions of pinnipeds to noise from 
open-water seismic exploration have been published (for review of the 
early literature, see Richardson et al. 1995). However, pinnipeds have 
been observed during a number of seismic monitoring studies. Monitoring 
in the Beaufort Sea during 1996-2002 provided a substantial amount of 
information on avoidance responses (or lack thereof) and associated 
behavior. Additional monitoring of that type has been done in the 
Beaufort and Chukchi Seas in 2006-2009. Pinnipeds exposed to seismic 
surveys have also been observed during seismic surveys along the U.S. 
west coast. Some limited data are available on physiological responses 
of pinnipeds exposed to seismic sound, as studied with the aid of radio 
telemetry. Also, there are data on the reactions of pinnipeds to 
various other related types of impulsive sounds.
    Early observations provided considerable evidence that pinnipeds 
are often quite tolerant of strong pulsed sounds. During seismic 
exploration off Nova Scotia, gray seals exposed to noise from airguns 
and linear explosive charges reportedly did not react strongly (J. 
Parsons in Greene et al. 1985). An airgun caused an initial startle 
reaction among South African fur seals but was ineffective in scaring 
them away from fishing gear. Pinnipeds in both water and air sometimes 
tolerate strong noise pulses from non-explosive and explosive scaring 
devices, especially if attracted to the area for feeding or 
reproduction (Mate and Harvey 1987; Reeves et al. 1996). Thus, 
pinnipeds are expected to be rather tolerant of, or to habituate to, 
repeated underwater sounds from distant seismic sources, at least when 
the animals are strongly attracted to the area.
    In summary, visual monitoring from seismic vessels has shown only 
slight (if any) avoidance of airguns by pinnipeds, and only slight (if 
any) changes in behavior. These studies show that many pinnipeds do not 
avoid the area within a few hundred meters of an operating airgun 
array. However, based on the studies with large sample size, or 
observations from a separate monitoring vessel, or radio telemetry, it 
is apparent that some phocid seals do show localized avoidance of 
operating airguns. The limited nature of this tendency for avoidance is 
a concern. It suggests that one cannot rely on pinnipeds to move away, 
or to move very far away, before received levels of sound from an 
approaching seismic survey vessel approach those that may cause hearing 
impairment.
(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 animal utilizes) 
overlap at both spectral and temporal scales. For the airgun noise 
generated from the proposed marine seismic survey, these are low 
frequency (under 1 kHz) pulses with extremely short durations (in the 
scale of milliseconds). Lower frequency man-made noises are more likely 
to affect detection of communication calls and other potentially 
important natural sounds such as surf and prey noise.

[[Page 49736]]

There is little concern regarding masking due to the brief duration of 
these pulses and relatively longer silence between airgun shots (9-12 
seconds) near the noise source, however, at long distances (over tens 
of kilometers away) in deep water, due to multipath propagation and 
reverberation, the durations of airgun pulses can be ``stretched'' to 
seconds with long decays (Madsen et al. 2006; Clark and Gagnon 2006). 
Therefore it could affect communication signals used by low frequency 
mysticetes when they occur near the noise band and thus reduce the 
communication space of animals (e.g., Clark et al. 2009a, 2009b) and 
cause increased stress levels (e.g., Foote et al. 2004; Holt et al. 
2009). Further, in areas of shallow water, multipath propagation of 
airgun pulses could be more profound, thus affecting communication 
signals from marine mammals even at close distances. Nevertheless, the 
intensity of the noise is also greatly reduced at such long distances.
    Although masking effects of pulsed sounds on marine mammal calls 
and other natural sounds are expected to be limited, there are few 
specific studies on this. Some whales continue calling in the presence 
of seismic pulses and whale calls often can be heard between the 
seismic pulses (e.g., Richardson et al. 1986; McDonald et al. 1995; 
Greene et al. 1999a, 1999b; Nieukirk et al. 2004; Smultea et al. 2004; 
Holst et al. 2005a, 2005b, 2006; Dunn and Hernandez 2009). However, 
there is one recent summary report indicating that calling fin whales 
distributed in one part of the North Atlantic went silent for an 
extended period starting soon after the onset of a seismic survey in 
the area (Clark and Gagnon 2006). It is not clear from that preliminary 
paper whether the whales ceased calling because of masking, or whether 
this was a behavioral response not directly involving masking. Also, 
bowhead whales in the Beaufort Sea may decrease their call rates in 
response to seismic operations, although movement out of the area might 
also have contributed to the lower call detection rate (Blackwell et 
al. 2009a; 2009b).
    Among the odontocetes, there has been one report that sperm whales 
ceased calling when exposed to pulses from a very distant seismic ship 
(Bowles et al. 1994). However, more recent studies of sperm whales 
found that they continued calling in the presence of seismic pulses 
(Madsen et al. 2002; Tyack et al. 2003; Smultea et al. 2004; Holst et 
al. 2006; Jochens et al. 2008). Madsen et al. (2006) noted that airgun 
sounds would not be expected to mask sperm whale calls given the 
intermittent nature of airgun pulses. Dolphins and porpoises are also 
commonly heard calling while airguns are operating (Gordon et al. 2004; 
Smultea et al. 2004; Holst et al. 2005a, 2005b; Potter et al. 2007). 
Masking effects of seismic pulses are expected to be negligible in the 
case of the smaller odontocetes, given the intermittent nature of 
seismic pulses plus the fact that sounds important to them are 
predominantly at much higher frequencies than are the dominant 
components of airgun sounds.
    Pinnipeds have best hearing sensitivity and/or produce most of 
their sounds at frequencies higher than the dominant components of 
airgun sound, but there is some overlap in the frequencies of the 
airgun pulses and the calls. However, the intermittent nature of airgun 
pulses presumably reduces the potential for masking.
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior such as shifting call frequencies, 
increasing call volume and vocalization rates. For example, blue whales 
are found to increase call rates when exposed to seismic survey noise 
in the St. Lawrence Estuary (Di Iorio and Clark 2009). The North 
Atlantic right whales (Eubalaena glacialis) exposed to high shipping 
noise increase call frequency (Parks et al. 2007), while some humpback 
whales respond to low-frequency active sonar playbacks by increasing 
song length (Miller et al. 2000).
(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.
    TTS: TTS is the mildest form of hearing impairment that can occur 
during exposure to a strong sound (Kryter 1985). While experiencing 
TTS, the hearing threshold rises and a sound must be stronger in order 
to be heard. It is a temporary phenomenon, and (especially when mild) 
is not considered to represent physical damage or ``injury'' (Southall 
et al. 2007). Rather, the onset of TTS is an indicator that, if the 
animal is exposed to higher levels of that sound, physical damage is 
ultimately a possibility.
    The magnitude of TTS depends on the level and duration of noise 
exposure, and to some degree on frequency, among other considerations 
(Kryter 1985; Richardson et al. 1995; Southall et al. 2007). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
recovers rapidly after exposure to the noise ends. In terrestrial 
mammals, TTS can last from minutes or hours to (in cases of strong TTS) 
days. Only a few data have been obtained on sound levels and durations 
necessary to elicit mild TTS in marine mammals (none in mysticetes), 
and none of the published data concern TTS elicited by exposure to 
multiple pulses of sound during operational seismic surveys (Southall 
et al. 2007).
    For toothed whales, experiments on a bottlenose dolphin (Tursiops 
truncates) and beluga whale showed that exposure to a single watergun 
impulse at a received level of 207 kPa (or 30 psi) peak-to-peak (p-p), 
which is equivalent to 228 dB re 1 [mu]Pa (p-p), resulted in a 7 and 6 
dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. Thresholds 
returned to within 2 dB of the pre-exposure level within 4 minutes of 
the exposure (Finneran et al. 2002). No TTS was observed in the 
bottlenose dolphin.
    Finneran et al. (2005) further examined the effects of tone 
duration on TTS in bottlenose dolphins. Bottlenose dolphins were 
exposed to 3 kHz tones (non-impulsive) for periods of 1, 2, 4 or 8 
seconds (s), with hearing tested at 4.5 kHz. For 1-s exposures, TTS 
occurred with SELs of 197 dB, and for exposures >1 s, SEL >195 dB 
resulted in TTS (SEL is equivalent to energy flux, in dB re 1 
[mu]Pa\2\-s). At an SEL of 195 dB, the mean TTS (4 min after exposure) 
was 2.8 dB. Finneran et al. (2005) suggested that an SEL of 195 dB is 
the likely threshold for the onset of TTS in dolphins and belugas 
exposed to tones of durations 1-8 s (i.e., TTS onset occurs at a near-
constant SEL, independent of exposure duration). That implies that, at 
least for non-impulsive tones, a doubling of exposure time results in a 
3 dB lower TTS threshold.
    However, the assumption that, in marine mammals, the occurrence and 
magnitude of TTS is a function of cumulative acoustic energy (SEL) is 
probably an oversimplification. Kastak et al. (2005) reported 
preliminary

[[Page 49737]]

evidence from pinnipeds that, for prolonged non-impulse noise, higher 
SELs were required to elicit a given TTS if exposure duration was short 
than if it was longer, i.e., the results were not fully consistent with 
an equal-energy model to predict TTS onset. Mooney et al. (2009a) 
showed this in a bottlenose dolphin exposed to octave-band non-impulse 
noise ranging from 4 to 8 kHz at SPLs of 130 to 178 dB re 1 [mu]Pa for 
periods of 1.88 to 30 minutes (min). Higher SELs were required to 
induce a given TTS if exposure duration was short than if it was 
longer. Exposure of the aforementioned bottlenose dolphin to a sequence 
of brief sonar signals showed that, with those brief (but non-impulse) 
sounds, the received energy (SEL) necessary to elicit TTS was higher 
than was the case with exposure to the more prolonged octave-band noise 
(Mooney et al. 2009b). Those authors concluded that, when using (non-
impulse) acoustic signals of duration ~0.5 s, SEL must be at least 210-
214 dB re 1 [mu]Pa2-s to induce TTS in the bottlenose dolphin. The most 
recent studies conducted by Finneran et al. also support the notion 
that exposure duration has a more significant influence compared to SPL 
as the duration increases, and that TTS growth data are better 
represented as functions of SPL and duration rather than SEL alone 
(Finneran et al. 2010a, 2010b). In addition, Finneran et al. (2010b) 
conclude that when animals are exposed to intermittent noises, there is 
recovery of hearing during the quiet intervals between exposures 
through the accumulation of TTS across multiple exposures. Such 
findings suggest that when exposed to multiple seismic pulses, partial 
hearing recovery also occurs during the seismic pulse intervals.
    For baleen whales, there are no data, direct or indirect, on levels 
or properties of sound that are required to induce TTS. The frequencies 
to which baleen whales are most sensitive are lower than those to which 
odontocetes are most sensitive, and natural ambient noise levels at 
those low frequencies tend to be higher (Urick 1983). As a result, 
auditory thresholds of baleen whales within their frequency band of 
best hearing are believed to be higher (less sensitive) than are those 
of odontocetes at their best frequencies (Clark and Ellison 2004). From 
this, it is suspected that received levels causing TTS onset may also 
be higher in baleen whales. However, no cases of TTS are expected given 
the small size of the airguns proposed to be used and the strong 
likelihood that baleen whales (especially migrating bowheads) would 
avoid the approaching airguns (or vessel) before being exposed to 
levels high enough for there to be any possibility of TTS.
    In pinnipeds, TTS thresholds associated with exposure to brief 
pulses (single or multiple) of underwater sound have not been measured. 
Initial evidence from prolonged exposures suggested that some pinnipeds 
may incur TTS at somewhat lower received levels than do small 
odontocetes exposed for similar durations (Kastak et al. 1999; 2005). 
However, more recent indications are that TTS onset in the most 
sensitive pinniped species studied (harbor seal, which is closely 
related to the ringed seal) may occur at a similar SEL as in 
odontocetes (Kastak et al. 2004).
    Most cetaceans show some degree of avoidance of seismic vessels 
operating an airgun array (see above). It is unlikely that these 
cetaceans would be exposed to airgun pulses at a sufficiently high 
level for a sufficiently long period to cause more than mild TTS, given 
the relative movement of the vessel and the marine mammal. TTS would be 
more likely in any odontocetes that bow- or wake-ride or otherwise 
linger near the airguns. However, while bow- or wake-riding, 
odontocetes would be at the surface and thus not exposed to strong 
sound pulses given the pressure release and Lloyd Mirror effects at the 
surface. But if bow- or wake-riding animals were to dive intermittently 
near airguns, they would be exposed to strong sound pulses, possibly 
repeatedly.
    If some cetaceans did incur mild or moderate TTS through exposure 
to airgun sounds in this manner, this would very likely be a temporary 
and reversible phenomenon. However, even a temporary reduction in 
hearing sensitivity could be deleterious in the event that, during that 
period of reduced sensitivity, a marine mammal needed its full hearing 
sensitivity to detect approaching predators, or for some other reason.
    Some pinnipeds show avoidance reactions to airguns, but their 
avoidance reactions are generally not as strong or consistent as those 
of cetaceans. Pinnipeds occasionally seem to be attracted to operating 
seismic vessels. There are no specific data on TTS thresholds of 
pinnipeds exposed to single or multiple low-frequency pulses. However, 
given the indirect indications of a lower TTS threshold for the harbor 
seal than for odontocetes exposed to impulse sound (see above), it is 
possible that some pinnipeds close to a large airgun array could incur 
TTS.
    Current NMFS' noise exposure standards require 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). 
These criteria were taken from recommendations by an expert panel of 
the High Energy Seismic Survey (HESS) Team that performed an assessment 
on noise impacts by seismic airguns to marine mammals in 1997, although 
the HESS Team recommended a 180-dB limit for pinnipeds in California 
(HESS 1999). The 180 and 190 dB re 1 [mu]Pa (rms) levels have not been 
considered to be the levels above which TTS might occur. Rather, they 
were the received levels above which, in the view of a panel of 
bioacoustics specialists convened by NMFS before TTS measurements for 
marine mammals started to become available, one could not be certain 
that there would be no injurious effects, auditory or otherwise, to 
marine mammals. As summarized above, data that are now available imply 
that TTS is unlikely to occur in various odontocetes (and probably 
mysticetes as well) unless they are exposed to a sequence of several 
airgun pulses stronger than 190 dB re 1 [mu]Pa (rms). On the other 
hand, for the harbor seal, harbor porpoise, and perhaps some other 
species, TTS may occur upon exposure to one or more airgun pulses whose 
received level equals the NMFS ``do not exceed'' value of 190 dB re 1 
[mu]Pa (rms). That criterion corresponds to a single-pulse SEL of 175-
180 dB re 1 [mu]Pa\2\-s in typical conditions, whereas TTS is suspected 
to be possible in harbor seals and harbor porpoises with a cumulative 
SEL of ~171 and ~164 dB re 1 [mu]Pa\2\-s, respectively.
    It has been shown that most large whales and many smaller 
odontocetes (especially the harbor porpoise) show at least localized 
avoidance of ships and/or seismic operations. Even when avoidance is 
limited to the area within a few hundred meters of an airgun array, 
that should usually be sufficient to avoid TTS based on what is 
currently known about thresholds for TTS onset in cetaceans. In 
addition, ramping up airgun arrays, which is standard operational 
protocol for many seismic operators, should allow cetaceans near the 
airguns at the time of startup (if the sounds are aversive) to move 
away from the seismic source and to avoid being exposed to the full 
acoustic output of the airgun array. Thus, most baleen whales likely 
will not be exposed to high levels of airgun sounds provided the ramp-
up procedure is applied. Likewise, many odontocetes close to the

[[Page 49738]]

trackline are likely to move away before the sounds from an approaching 
seismic vessel become sufficiently strong for there to be any potential 
for TTS or other hearing impairment. Hence, there is little potential 
for baleen whales or odontocetes that show avoidance of ships or 
airguns to be close enough to an airgun array to experience TTS. 
Therefore, it is not likely that marine mammals in the vicinity of the 
proposed open water marine and seismic surveys by Shell and Statoil 
would experience TTS as a result of these activities.
    PTS: When PTS occurs, there is physical damage to the sound 
receptors in the ear. In some cases, there can be total or partial 
deafness, whereas in other cases, the animal has an impaired ability to 
hear sounds in specific frequency ranges (Kryter 1985). Physical damage 
to a mammal's hearing apparatus can occur if it is exposed to sound 
impulses that have very high peak pressures, especially if they have 
very short rise times. (Rise time is the interval required for sound 
pressure to increase from the baseline pressure to peak pressure.)
    There is no specific evidence that exposure to pulses of airgun 
sound can cause PTS in any marine mammal, even with large arrays of 
airguns. However, given the likelihood that some mammals close to an 
airgun array might incur at least mild TTS (see above), there has been 
further speculation about the possibility that some individuals 
occurring very close to airguns might incur PTS (e.g., Richardson et 
al. 1995; Gedamke et al. 2008). Single or occasional occurrences of 
mild TTS are not indicative of permanent auditory damage, but repeated 
or (in some cases) single exposures to a level well above that causing 
TTS onset might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, but are assumed to be similar to those in humans and 
other terrestrial mammals (Southall et al. 2007). Based on data from 
terrestrial mammals, a precautionary assumption is that the PTS 
threshold for impulse sounds (such as airgun pulses as received close 
to the source) is at least 6 dB higher than the TTS threshold on a 
peak-pressure basis, and probably >6 dB higher (Southall et al. 2007). 
The low-to-moderate levels of TTS that have been induced in captive 
odontocetes and pinnipeds during controlled studies of TTS have been 
confirmed to be temporary, with no measurable residual PTS (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005; Nachtigall 
et al. 2003; 2004). However, very prolonged exposure to sound strong 
enough to elicit TTS, or shorter-term exposure to sound levels well 
above the TTS threshold, can cause PTS, at least in terrestrial mammals 
(Kryter 1985). In terrestrial mammals, the received sound level from a 
single non-impulsive sound exposure must be far above the TTS threshold 
for any risk of permanent hearing damage (Kryter 1994; Richardson et 
al. 1995; Southall et al. 2007). However, there is special concern 
about strong sounds whose pulses have very rapid rise times. In 
terrestrial mammals, there are situations when pulses with rapid rise 
times (e.g., from explosions) can result in PTS even though their peak 
levels are only a few dB higher than the level causing slight TTS. The 
rise time of airgun pulses is fast, but not as fast as that of an 
explosion.
    Some factors that contribute to onset of PTS, at least in 
terrestrial mammals, are as follows:
     Exposure to single very intense sound,
     Fast rise time from baseline to peak pressure,
     Repetitive exposure to intense sounds that individually 
cause TTS but not PTS, and
     Recurrent ear infections or (in captive animals) exposure 
to certain drugs.
    Cavanagh (2000) reviewed the thresholds used to define TTS and PTS. 
Based on this review and SACLANT (1998), it is reasonable to assume 
that PTS might occur at a received sound level 20 dB or more above that 
inducing mild TTS. However, for PTS to occur at a received level only 
20 dB above the TTS threshold, the animal probably would have to be 
exposed to a strong sound for an extended period, or to a strong sound 
with rather rapid rise time.
    More recently, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB, on an 
SEL basis, for there to be risk of PTS. Thus, for cetaceans exposed to 
a sequence of sound pulses, they estimate that the PTS threshold might 
be an M-weighted SEL (for the sequence of received pulses) of ~198 dB 
re 1 [mu]Pa\2\-s. Additional assumptions had to be made to derive a 
corresponding estimate for pinnipeds, as the only available data on 
TTS-thresholds in pinnipeds pertained to nonimpulse sound (see above). 
Southall et al. (2007) estimated that the PTS threshold could be a 
cumulative SEL of ~186 dB re 1 [mu]Pa\2\-s in the case of a harbor seal 
exposed to impulse sound. The PTS threshold for the California sea lion 
and northern elephant seal would probably be higher given the higher 
TTS thresholds in those species. Southall et al. (2007) also note that, 
regardless of the SEL, there is concern about the possibility of PTS if 
a cetacean or pinniped received one or more pulses with peak pressure 
exceeding 230 or 218 dB re 1 [mu]Pa, respectively. Thus, PTS might be 
expected upon exposure of cetaceans to either SEL >=198 dB re 1 
[mu]Pa2-s or peak pressure >=230 dB re 1 [mu]Pa. Corresponding proposed 
dual criteria for pinnipeds (at least harbor seals) are >=186 dB SEL 
and >= 218 dB peak pressure (Southall et al. 2007). These estimates are 
all first approximations, given the limited underlying data, 
assumptions, species differences, and evidence that the ``equal 
energy'' model may not be entirely correct.
    Sound impulse duration, peak amplitude, rise time, number of 
pulses, and inter-pulse interval are the main factors thought to 
determine the onset and extent of PTS. Ketten (1994) has noted that the 
criteria for differentiating the sound pressure levels that result in 
PTS (or TTS) are location and species specific. PTS effects may also be 
influenced strongly by the health of the receiver's ear.
    As described above for TTS, in estimating the amount of sound 
energy required to elicit the onset of TTS (and PTS), it is assumed 
that the auditory effect of a given cumulative SEL from a series of 
pulses is the same as if that amount of sound energy were received as a 
single strong sound. There are no data from marine mammals concerning 
the occurrence or magnitude of a potential partial recovery effect 
between pulses. In deriving the estimates of PTS (and TTS) thresholds 
quoted here, Southall et al. (2007) made the precautionary assumption 
that no recovery would occur between pulses.
    It is unlikely that an odontocete would remain close enough to a 
large airgun array for sufficiently long to incur PTS. There is some 
concern about bowriding odontocetes, but for animals at or near the 
surface, auditory effects are reduced by Lloyd's mirror and surface 
release effects. The presence of the vessel between the airgun array 
and bow-riding odontocetes could also, in some but probably not all 
cases, reduce the levels received by bow-riding animals (e.g., Gabriele 
and Kipple 2009). The TTS (and thus PTS) thresholds of baleen whales 
are unknown but, as an interim measure, assumed to be no lower than 
those of odontocetes. Also, baleen whales generally avoid the immediate 
area around operating seismic vessels, so it is unlikely that a baleen 
whale could incur PTS from exposure to airgun pulses. The TTS (and thus 
PTS) thresholds of some pinnipeds (e.g., harbor seal) as well as the 
harbor

[[Page 49739]]

porpoise may be lower (Kastak et al. 2005; Southall et al. 2007; Lucke 
et al. 2009). If so, TTS and potentially PTS may extend to a somewhat 
greater distance for those animals. Again, Lloyd's mirror and surface 
release effects will ameliorate the effects for animals at or near the 
surface.
(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 intense sounds. 
However, there is no definitive evidence that any of these effects 
occur even for marine mammals in close proximity to large arrays of 
airguns, and beaked whales do not occur in the proposed project area. 
In addition, marine mammals that show behavioral avoidance of seismic 
vessels, including most baleen whales, some odontocetes (including 
belugas), and some pinnipeds, are especially unlikely to incur non-
auditory impairment or other physical effects. 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; Ketten 1995). 
Airgun pulses are less energetic and their peak amplitudes have slower 
rise times, while stranding and mortality events would include other 
energy sources (acoustical or shock wave) far beyond just seismic 
airguns. To date, there is no evidence that serious injury, death, or 
stranding by marine mammals can occur from exposure to airgun pulses, 
even in the case of large airgun arrays.
    However, in numerous past IHA notices for seismic surveys, 
commenters have referenced two stranding events allegedly associated 
with seismic activities, one off Baja California and a second off 
Brazil. NMFS has addressed this concern several times, and, without new 
information, does not believe that this issue warrants further 
discussion. For information relevant to strandings of marine mammals, 
readers are encouraged to review NMFS' response to comments on this 
matter found in 69 FR 74906 (December 14, 2004), 71 FR 43112 (July 31, 
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 
2006). 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, use of the equipment is not expected to cause any take of 
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 have been 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

[[Page 49740]]

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 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.

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) are 
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 do 
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 proposed open water marine survey programs.
    For impulse sounds, such as those produced by airgun(s) used for 
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 
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

[[Page 49741]]

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 
scour 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

     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 re 1
                                                                                           Modeled                        [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      190 & 240 kHz..........          225    Not modeled/measured because frequency outputs
                                        scan.                                                                 beyond marine mammal hearing range.
                                      ------------------------------------------------------------------------------------------------------------------
                                       Single beam echo sound.  100-340 kHz............      180-200  Not modeled/measured because majority of frequency
                                                                                                          outputs beyond marine mammal hearing range.
                                      ------------------------------------------------------------------------------------------------------------------
                                       Shallow sub-bottom       3.5 kHz (Alpha Helix)..        193.8            1            3           14          310
                                        profiler.
                                                               -----------------------------------------------------------------------------------------
                                                                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 outputs
                                        Sonar.                                                                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 by 
the area of water body 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 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.

[[Page 49742]]

    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 Beaufort Sea 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 
of bowhead whales, some of which are in feeding aggregations, are found 
in the eastern Alaskan Beaufort Sea and the northeastern Chukchi Sea. 
Belugas begin to move across the Alaskan Beaufort Sea in August, and 
the majority of 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 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
----------------------------------------------------------------------------------------------------------------
Species...........................  Average Density (/km\2\)....  Average Density (/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
----------------------------------------------------------------------------------------------------------------
Species...........................  Average Density (/km \2\)...  Average Density (/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.


[[Page 49743]]

    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 density (/km  Average density (/km
                      Species                                    \2\)                           \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).
    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;

[[Page 49744]]

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 array 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 array 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 the 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, it is 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 in the Beaufort Sea, 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 49745]]



 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 exposure to
                Species                     sound 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).

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. (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.
    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

[[Page 49746]]

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 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

[[Page 49747]]

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's POC is also subject 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 identifies 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 details 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 states that through its Subsistence Advisor (SA) and 
Com and Call Center (Com Center) program for 2010, Shell's SA and Shell 
representatives in the Com Centers will be available daily to the 
communities throughout the 2010 season. The SA and Com Center programs 
provide residents of the nearest affected communities a way to 
communicate where and when subsistence activities so that industry may 
avoid conflicts with planned subsistence activities. 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 
attached to the POC as addenda and were 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 
were conducted 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, Eskimo Walrus Commission, Alaska Beluga Whale 
Committee, Alaska Ice Seal Committee, and the Alaska Nanuuq Commission 
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.

Mitigation Measures

    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 Shell's proposed 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.
    For the proposed Shell's 2010 open water marine survey program in 
the Beaufort and Chukchi Seas, the following mitigation measures are 
required.

(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 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

[[Page 49748]]

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.
    Power density spectra (frequency spectra) of high frequency active 
acoustic sources (operating frequency >180 kHz) that will be used in 
Shell's marine surveys will also be measured against ambient background 
noise levels and reported in 1/3-octave band and 1-Hz band from 10 Hz 
to 180 kHz. The purpose for this measurement is to determine whether 
there is any acoustic energy within marine mammal hearing ranges that 
would be generated from operating these high frequency acoustic 
sources.

(2) Safety and Disturbance Zones

    Under current NMFS guidelines, ``safety radii'' for marine mammal 
exposure to impulse sources are customarily defined as the distances 
within which received sound levels are >=180 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 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:

[[Page 49749]]

     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.
    In the unanticipated event that an injured or dead marine mammal is 
sighted within an area where Shell deployed and utilized seismic 
airguns within the past 24 hours, Shell will immediately shutdown the 
seismic airgun array and notify the Marine Mammal Stranding Network 
within 24 hours of the sighting.
    In the event that the marine mammal has been determined to have 
been deceased for at least 72 hours, as certified by the lead MMO 
onboard the source vessel, and no other marine mammals have been 
reported injured or dead during that same 72 hour period, the airgun 
array may be restarted (by conducting the necessary ramp-up procedures 
described elsewhere in this section of the document) upon completion of 
a written certification by the MMO. The certification must include the 
following: species or description of the animal(s); the condition of 
the animal(s) (including carcass condition if the animal is dead); 
location and time of first discovery; observed behaviors (if alive); 
and photographs or video (if available). Within 24 hours after the 
event specified herein, Shell must notify NMFS by telephone or email of 
the event and ensure that the written certification is provided to 
NMFS.
    In the event that the marine mammal injury resulted from something 
other than seismic airgun operations (e.g., gunshot wound, polar bear 
attack), as certified by the lead MMO onboard the seismic vessel, the 
airgun array may be restarted (by conducting the necessary ramp-up 
procedures described elsewhere in this section of the document) upon 
completion of a written certification by the MMO. The certification 
must include the following: species or description of the animal(s); 
the condition of the animal(s) (including carcass condition if the 
animal is dead); location and time of first discovery; observed 
behaviors (if alive); and photographs or video (if available). Within 
24 hours after the event specified herein, Shell must notify NMFS by 
telephone or email of the event and ensure that the written 
certification is provided to NMFS.
    In the event the animal has not been dead for a period greater than 
72 hours or the cause of the injury or death cannot be immediately 
determined by the lead MMO, Shell shall immediately report the incident 
to either the NMFS staff person designated by the Director, Office of 
Protected Resources or to the staff person designated by the Alaska 
Regional Administrator. The lead MMO must complete written 
certification and provide it to the NMFS staff person. The 
certification must include the following: species or description of the 
animal(s); the condition of the animal(s) (including carcass condition 
if the animal is dead); location and time of first discovery; observed 
behaviors (if alive); and photographs or video (if available). The 
airgun array may be restarted (by conducting the necessary ramp-up 
procedures described elsewhere in this section of the document) upon 
completion of the written certification.
    In the event that the marine mammal death or injury was directly 
caused by the seismic airgun operations (e.g., struck by a vessel, 
entangled in gear), Shell shall immediately report the incident to the 
designated NMFS staff person by telephone or email and the Marine 
Mammal Stranding Network of the event and ensure that written 
certification is provided to the NMFS staff person. The certification 
must include the following: species or description of the animal(s); 
the condition of the animal(s) (including carcass condition if the 
animal is dead); location and time of first discovery; observed 
behaviors (if alive); and photographs or video (if available). The 
airguns may not be restarted until NMFS has had an opportunity to 
review the written certification and any accompanying documentation, 
make determinations as to whether modifications to the activities are 
appropriate and necessary, and has notified Shell that activities may 
be resumed. Approval to resume operations may be provided via letter, 
e-mail, or telephone.

(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 
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.
    To help evaluate the utility and effectiveness of ramp-up 
procedures, MMOs are required to record and report their observations 
during any ramp-up period.

(5) Mitigation Measures Concerning Bowhead Cow/Calf Pairs and Whale 
Aggregations

    For seismic activities (including shallow hazards and site 
clearance and

[[Page 49750]]

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 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 whale aggregations, 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.

(6) Mitigation Measures Concerning Vessel Speed and Directions

    Furthermore, the following measures concerning vessel speed and 
directions are required for Shell's 2010 open water marine survey 
program in the Beaufort and Chukchi Seas:
     All vessels should reduce speed to below 10 knots 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;
     Avoid multiple changes in direction and speed when within 
300 yards (274 m) of whales; and
     When weather conditions require, such as when visibility 
drops, support vessels must adjust speed accordingly to avoid the 
likelihood of injury to whales.

(7) Subsistence Mitigation Measures

    The following mitigation measures, plans, and programs shall be 
implemented to reduce impacts from Shell's marine surveys that could 
potentially affect 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.
    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:
     For the purposes of reducing or eliminating conflicts 
between subsistence whaling activities and Shell's survey program, 
Shell will participate with other operators in the Communication and 
Call Centers (Com-Center) Program. The Com-Centers will be operated 24 
hours/day during the 2010 fall subsistence bowhead whale hunt.
     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 Com-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 to 
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; 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.
     Upon notification by a Com-Center operator of an at-sea 
emergency, Shell will provide such assistance as necessary to prevent 
the loss of life, if conditions allow the holder of this Authorization 
to safely do so.
     Upon request for emergency assistance made by a 
subsistence whale hunting organization, or by a member of such an 
organization, in order to prevent the loss of a whale, the holder of 
this Authorization shall assist towing of a whale taken in a 
traditional subsistence whale hunt, if conditions allow Shell to safely 
do so.
     Post-season Review: Following completion of the 2010 
Beaufort and Chukchi Seas open water marine survey program, Shell will 
conduct a 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.

[[Page 49751]]

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 evaluations and analyses of the aforementioned 
mitigation measures, NMFS has determined that the 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, and 
will have no unmitigable impact to subsistence hunt.

Monitoring and Reporting Measures

    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

    The following monitoring measures are required for Shell's 2010 
open water marine survey program in the Beaufort and Chukchi Seas.
(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. New observers shall be paired with 
experienced observers to avoid situations where lack of experience 
impairs the quality of observations. 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 email, 
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 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. Observers should be 
trained using visual aids (e.g., videos, photos), to help them identify 
the species that they are likely to encounter in the conditions under 
which the animals will likely be seen.
    If there are Alaska Native MMOs, the MMO training that is conducted 
prior to the start of the survey activities should be conducted with 
both Alaska Native MMOs and biologist MMOs being trained at the same 
time in the same room. There should not be separate training courses 
for the different MMOs.
    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; and
     Review of the specific tasks of the Inupiat Communicator.
    Observers should understand the importance of classifying marine 
mammals as ``unknown'' or ``unidentified'' if they cannot identify the 
animals to species with confidence. In those cases, they should note 
any information that might aid in the identification of the marine 
mammal sighted. For example, for an unidentified mysticete whale, the 
observers should record whether the animal had a dorsal fin.
    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

[[Page 49752]]

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. With two or three observers on watch, the 
use of big eyes should be paired with searching by naked eye, the 
latter allowing visual coverage of nearby areas to detect marine 
mammals. Personnel on the bridge will assist the MMOs in watching for 
marine mammals.
    Observers should attempt to maximize the time spent looking at the 
water and guarding the safety radii. They should avoid the tendency to 
spend too much time evaluating animal behavior or entering data on 
forms, both of which detract from their primary purpose of monitoring 
the safety zone.
    Observers should use the best possible positions for observing 
(e.g., outside and as high on the vessel as possible), taking into 
account weather and other working conditions. MMOs shall carefully 
document visibility during observation periods so that total estimates 
of take can be corrected accordingly.
    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;
    (C) The positions of other vessel(s) in the vicinity of the MMO 
location; and
    (D) Whether adjustments were made to Shell's activity status.
    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 1,968 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 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

[[Page 49753]]

but are suitable for both bowhead and beluga whales. The need for a 
900-1,000+ (374-305 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.
    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

[[Page 49754]]

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).

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. The Technical Reports will include: (a) 
Summaries of monitoring effort (e.g., total hours, total distances, and 
marine mammal distribution through the study period, accounting for sea 
state and other factors affecting visibility and detectability of 
marine mammals); (b) analyses of the effects of various factors 
influencing detectability of marine mammals (e.g., sea state, number of 
observers, and fog/glare); (c) species composition, occurrence, and 
distribution of marine mammal sightings, including date, water depth, 
numbers, age/size/gender categories (if determinable), group sizes, and 
ice cover; (d) 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. In addition, Shell 
shall provide all spatial data on charts (always including vessel 
location) and make all data available in the report, preferably 
electronically, for integration with data from other companies. Shell 
shall also accommodate specific requests for raw data, including tracks 
of all vessels and aircraft associated with the operation and activity 
logs documenting when and what types of sounds are introduced into the 
environment by the operation.
    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.

[[Page 49755]]

(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.
Negligible Impact and Small Numbers Analysis and 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, as 
discussed previously in this document, 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.
    The proposed marine survey areas in the Beaufort and Chukchi Seas 
are not known habitat for breeding or calving for marine mammals during 
the time of the proposed marine survey activities.
    Although bowhead whales are observed feeding in the Beaufort and 
Chukchi Seas during the summer, some studies have shown that bowhead 
whales will continue to feed in areas of seismic operations (e.g., 
Richardson et al. 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

[[Page 49756]]

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 sound multiple times is much lower than if the source is stationary. 
Therefore, NMFS has 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 affected 
species or stock.
    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 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 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.

Unmitigable Adverse Impact Analysis and Determination

    NMFS has 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 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

[[Page 49757]]

vessel. The vessel will transit an area, with the AUV surveying the 
area behind the vessel. Marine mammal observers onboard the vessel will 
help to ensure the AUV has a minimal impact on the environment. The AUV 
also has a Collision Avoidance System and operates without a towline, 
thereby reducing 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 more quickly 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 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 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 POC, the 
proposed mitigation and monitoring measures, and the project design, 
NMFS has determined 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 consulted with NMFS' Alaska Regional Office 
Division of Protected Resources 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. A Biological Opinion was issued on July 13, 2010, which 
concludes that issuance of an IHA is not likely to jeopardize the 
continued existence of the fin, humpback, or bowhead whale. NMFS has 
issued an Incidental Take Statement under this Biological Opinion which 
contains reasonable and prudent measures with implementing terms and 
conditions to minimize the effects of take of listed species.

National Environmental Policy Act (NEPA)

    NMFS prepared an EA that includes an analysis of potential 
environmental effects associated with NMFS' issuance of an IHA to Shell 
to take marine mammals incidental to conducting its marine survey 
program in the Beaufort and Chukchi Seas during 2010 open water season. 
NMFS has finalized the

[[Page 49758]]

EA and prepared a FONSI for this action. Therefore, preparation of an 
EIS is not necessary.

Authorization

    As a result of these determinations, NMFS has issued an IHA to 
Shell to take marine mammals incidental to its 2010 open water marine 
surveys in the Beaufort and Chukchi Seas, Alaska, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: August 6, 2010.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2010-19950 Filed 8-12-10; 8:45 am]
BILLING CODE 3510-22-P