Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to an Exploration Drilling Program in the Chukchi Sea, Alaska, 27322-27356 [2012-11094]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 77, Number 90 (Wednesday, May 9, 2012)]
[Notices]
[Pages 27322-27356]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-11094]



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Vol. 77

Wednesday,

No. 90

May 9, 2012

Part III





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 an Exploration Drilling Program in the 
Chukchi Sea, Alaska; Notice

Federal Register / Vol. 77 , No. 90 / Wednesday, May 9, 2012 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XA811


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to an Exploration Drilling Program in 
the Chukchi Sea, Alaska

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

ACTION: Notice; issuance of an incidental harassment 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 Gulf of Mexico Inc. 
(Shell) to take marine mammals, by harassment, incidental to offshore 
exploration drilling on Outer Continental Shelf (OCS) leases in the 
Chukchi Sea, Alaska.

DATES: Effective July 1, 2012, through October 31, 2012.

ADDRESSES: A copy of the issued IHA, application with associated 
materials, and NMFS' Environmental Assessment (EA) and Finding of No 
Significant Impact (FONSI) may be obtained by writing to Tammy Adams, 
Acting Chief, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service, 1315 East-West Highway, 
Silver Spring, MD 20910, telephoning the contact listed below (see FOR 
FURTHER INFORMATION CONTACT), or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited in this 
notice may also be viewed, by appointment, during regular business 
hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Candace Nachman, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

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

Summary of Request

    NMFS received an application on June 30, 2011, from Shell for the 
taking, by harassment, of marine mammals incidental to offshore 
exploration drilling on OCS leases in the Chukchi Sea, Alaska. NMFS 
reviewed Shell's application and identified a number of issues 
requiring further clarification. After addressing comments from NMFS, 
Shell modified its application and submitted a revised application on 
September 12, 2011. NMFS carefully evaluated Shell's application, 
including their analyses, and deemed the application complete. The 
September 12, 2011, application is the one available for public comment 
(see ADDRESSES) and considered by NMFS for this IHA. NMFS published a 
Notice of Proposed IHA in the Federal Register on November 9, 2011 (76 
FR 69958). That notice contained in depth descriptions and analyses 
that are generally not repeated in this document. Only in cases where 
descriptions or analyses changed is that information updated here. The 
most notable changes include: (1) Modifications to the aerial 
monitoring program presented in the marine mammal monitoring plan; and 
(2) updated information regarding Shell's Oil Spill Response Plan 
(OSRP).
    Shell plans to drill up to three exploration wells at three 
possible drill sites and potentially a partial well at a fourth drill 
site on OCS leases offshore in the Chukchi Sea, Alaska, during the 2012 
Arctic open-water season (July through October). Impacts to marine 
mammals may occur from noise produced by the drillship, zero-offset 
vertical seismic profile (ZVSP) surveys, and supporting vessels 
(including icebreakers) and aircraft. Shell requested authorization to 
take 13 marine mammal species by Level B harassment. However, the 
narwhal (Monodon monoceros) is not expected to be found in the activity 
area. Therefore, NMFS has authorized take of 12 marine mammal species, 
by Level B harassment, incidental to Shell's offshore exploration 
drilling in the Chukchi Sea. These species include: beluga whale 
(Delphinapterus leucas); bowhead whale (Balaena mysticetus); gray whale 
(Eschrichtius robustus); killer whale (Orcinus orca); minke whale 
(Balaenoptera acutorostrata); fin whale (Balaenoptera physalus); 
humpback whale (Megaptera novaeangliae); harbor porpoise (Phocoena 
phocoena); bearded seal (Erignathus barbatus); ringed seal (Phoca 
hispida); spotted seal (P. largha); and ribbon seal (Histriophoca 
fasciata).

Description of the Specified Activity and Specified Geographic Region

    Shell plans to conduct an offshore exploration drilling program on 
U.S. Department of the Interior, Bureau of Ocean Energy Management 
(BOEM, formerly the Minerals Management Service) Alaska OCS leases 
located greater than 64 mi (103 km) from the Chukchi Sea coast during 
the 2012 open-water season. The leases were acquired during the Chukchi 
Sea Oil and Gas Lease Sale 193 held in February 2008. During the 2012 
drilling program, Shell plans to drill up to three exploration wells at 
three drill sites and potentially a partial well at a fourth drill site 
at the prospect known as Burger. See Figure 1-1 in Shell's application 
for the lease block and drill site locations

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(see ADDRESSES). All drilling is planned to be vertical.
    The Notice of Proposed IHA (76 FR 69958, November 9, 2011) 
contained a full description of Shell's planned operations. That notice 
describes the equipment to be used for the different operational 
activities, the timeframe of activities, and the sound characteristics 
of the associated equipment. Except to clarify changes to the 
information contained in the proposed IHA notice, the information is 
not repeated here; therefore, please refer to the proposed IHA for the 
full description of the specified activity and specified geographic 
region.

Drilling Vessel

    Shell intends to use the ice strengthened drillship Discoverer to 
drill the wells. The Notice of Proposed IHA (76 FR 69958, November 9, 
2011) included the incorrect maximum anchor radius for the 8-point 
anchored mooring system. While on location at the Burger prospect drill 
sites, the maximum anchor radius is anticipated to be 2,609-2,904 ft 
(795-885 m).

Comments and Responses

    A Notice of Proposed IHA published in the Federal Register on 
November 9, 2011 (76 FR 69958) for public comment. During the 30-day 
public comment period, NMFS received 10 comment letters from the 
following: the Alaska Eskimo Whaling Commission (AEWC); Inupiat 
Community of the Arctic Slope (ICAS); the Marine Mammal Commission 
(MMC); State of Alaska Department of Natural Resources; Consumer Energy 
Alliance; Resource Development Council; the North Slope Borough (NSB); 
BOEM; Shell; and Alaska Wilderness League (AWL), Audubon Alaska, Center 
for Biological Diversity, Defenders of Wildlife, Earthjustice, Natural 
Resources Defense Council, Northern Alaska Environmental Center, Ocean 
Conservancy, Oceana, Pacific Environment, Resisting Environmental 
Destruction on Indigenous Lands, Sierra Club, the Wilderness Society, 
and World Wildlife Fund (collectively ``AWL''), along with an attached 
letter from David E. Bain, Ph.D.
    AWL submitted several journal articles and documents as attachments 
to their comment letter. NMFS acknowledges receipt of these articles 
and documents but does not intend to address each one specifically in 
the responses to comments. All of the public comment letters received 
on the Notice of Proposed IHA (76 FR 69958, November 9, 2011) are 
available on the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Following are the public comments and NMFS' responses.

General Comments

    Comment 1: Shell notes that the proposed IHA states that the IHA 
application was submitted by Shell Offshore Inc. when in fact it was 
submitted by Shell Gulf of Mexico Inc.
    Response: NMFS has corrected this error. It does not change any 
analyses.
    Comment 2: Shell notes that the proposed IHA contained the wrong 
anchor radius information for the Discoverer at the Burger prospect.
    Response: NMFS has updated that information in the description 
found earlier in this document. Because the radius is smaller than what 
was contained in the proposed IHA, it does not alter the analysis.
    Comment 3: Shell notes that the community of Point Hope is located 
approximately 206 mi (332 km) from the Burger prospect, not 180 mi (290 
km) as indicated in the proposed IHA.
    Response: NMFS has updated that information in this notice. Because 
the distance is farther, it does not alter the analysis.
    Comment 4: The State of Alaska Department of Natural Resources, 
Consumer Energy Alliance, and Resource Development Council all urge 
NMFS to finalize Shell's IHA since NMFS has issued the proposed IHA.
    Response: After careful evaluation of all comments and the data and 
information available regarding potential impacts to marine mammals and 
their habitat and to the availability of marine mammals for subsistence 
uses, NMFS has issued the final authorization to Shell to take marine 
mammals incidental to conducting an exploration drilling program in the 
Chukchi Sea during the 2012 Arctic open-water season.
    Comment 5: ICAS incorporates the comments made by the AEWC into its 
letter by reference and urges NMFS to address the concerns of AEWC and 
its whaling captains.
    Response: All comments made by the AEWC are addressed in this 
document.
    Comment 6: The NSB stated in their letter that comments made 
previously on Shell's IHA applications for seismic and drilling are 
still applicable and are incorporated by reference into their letter 
dated December 9, 2011.
    Response: NMFS has responded to comments on Shell's seismic IHA 
requests in previous Federal Register notices. Those responses are 
incorporated into this document by reference (e.g., 73 FR 66106, 
November 6, 2008; 74 FR 55368, October 27, 2009; 75 FR 49710, August 
13, 2010). The NSB submitted letters regarding Shell's proposed Camden 
Bay exploration drilling programs for the years 2007, 2008, and 2010. 
Shell did not request (and NMFS did not propose to issue or issue) IHAs 
for exploratory drilling programs in the Chukchi Sea in 2007 and 2008. 
Shell did request an IHA (and NMFS published a Notice of Proposed IHA) 
for a 2010 exploratory drilling program in the Chukchi Sea. However, 
the NSB did not submit a letter regarding that program. NMFS has only 
provided responses to comments contained in the 2007, 2008, and 2010 
letters that are different from comments in the NSB's 2011 letter on 
this IHA. Additionally, some of the comments in those three earlier 
letters are no longer relevant to Shell's program as currently proposed 
in this document.

MMPA Statutory Concerns

    Comment 7: The NSB states that the proposed IHA does not 
demonstrate that Shell's activities will take only a small number and 
have only a negligible impact on the species or stock. Additionally, 
the proposed IHA fails to distinguish between these two standards.
    Response: NMFS is required to authorize the take of ``small 
numbers'' of a species or stock if the taking by harassment will have a 
negligible impact on the affected species or stocks and will not have 
an unmitigable adverse impact on the availability of such species or 
stock for taking for subsistence purposes. See 16 U.S.C. 1371(a)(5)(D). 
In determining whether to authorize ``small numbers'' of a species or 
stock, NMFS determines that the taking will be small relative to the 
estimated population size and relevant to the behavior, physiology, and 
life history of the species or stock. With the exception of killer and 
minke whales, less than 1% of each species stock or population would be 
taken by Level B harassment incidental to Shell's activities. The 
modeling results indicate that only 1.2-1.85% of the minke whale 
population and 2.3% of the killer whale population would be taken by 
Level B harassment. NMFS is confident that takes resulting from Shell's 
activities will constitute only a ``small number'' of affected species 
or stocks for the following reasons:
    (1) In all of the modeling submitted by Shell, a 1.5x correction 
factor was included;
    (2) The estimated take levels do not mean that those numbers will 
actually be ``taken'' by Level B behavioral harassment. Some marine 
mammal species, such as bowheads, may engage

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in avoidance behavior preventing their exposure to these levels of 
sound, and, even if exposed, may not exhibit a behavioral reaction; and
    (3) The modeling results do not take into account the 
implementation of mitigation measures, which will lower the number of 
animals taken even further.
    In making a negligible impact determination, NMFS considers a 
variety of factors, including: (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. NMFS has determined that Shell's 
activities will not result in injury or mortality of marine mammals. 
The proposed IHA analyzed the number, nature, intensity, and duration 
of the Level B harassment that may occur and the context in which it 
may occur. That analysis led us to make a negligible impact finding.
    Comment 8: The AEWC and AWL state that NMFS cannot make a 
negligible impact determination without considering other activities 
planned for this year and future years in the U.S. Arctic Ocean and 
Russian and Canadian waters. AWL states that NMFS should also evaluate 
the potential impacts of future activities in both oceans and the 
acknowledged uncertainty regarding the effects of noise in the marine 
environment in the context of subsistence hunting.
    Response: NMFS considered the cumulative effects analysis contained 
in NMFS' Draft Environmental Impact Statement (EIS) on the ``Effects of 
Oil and Gas Activities in the Arctic Ocean'' (NMFS, 2011), NMFS' EA for 
the ``Issuance of Incidental Harassment Authorizations for the Take of 
Marine Mammals by Harassment Incidental to Conducting Exploratory 
Drilling Programs in the U.S. Beaufort and Chukchi Seas,'' and other 
relevant data to inform its MMPA determination here. Pursuant to the 
National Environmental Policy Act (NEPA), those documents contained a 
cumulative impacts assessment, as well as an assessment of the impacts 
of the proposed exploratory drilling program on marine mammals and 
other protected resources.
    Section 101(a)(5)(D) of the MMPA and its implementing regulations 
require NMFS to consider a request for the taking of marine mammals 
incidental to a specified activity within a specified geographical 
region and, assuming certain findings can be made, to authorize the 
taking of small numbers of marine mammals while engaged in that 
activity. NMFS has defined ``specified activity'' in 50 CFR 216.103 as 
``any activity, other than commercial fishing, that takes place in a 
specified geographical region and potentially involves the taking of 
small numbers of marine mammals.'' When making a negligible impact 
determination, NMFS considers the total impact during each 1-year 
period resulting from the specified activity only and supports its 
determination by relying on factors such as: (1) The number of 
anticipated mortalities from the activity; (2) the number and nature of 
anticipated injuries from the activity; (3) the number, nature, 
intensity, and duration of Level B harassment resulting from the 
activity; (4) the context in which the takes occur; (5) the status of 
the species or stock; (6) environmental features that may significantly 
increase the potential severity of impacts from the proposed action; 
(7) effects on habitat that could affect rates of recruitment or 
survival; and (8) how the mitigation measures are expected to reduce 
the number or severity of takes or the impacts to habitat. When making 
its finding that there will be no unmitigable adverse impact on the 
availability of the affected species or stock for taking for 
subsistence uses, NMFS analyzes the measures contained in the 
applicant's Plan of Cooperation (POC). Additionally, Shell signed the 
2012 Conflict Avoidance Agreement (CAA) with the AEWC. NMFS included 
all necessary measures from both documents in the IHA to ensure no 
unmitigable adverse impacts to subsistence.
    NMFS considered the impacts analyses (i.e., direct, indirect, and 
cumulative) contained in the previously mentioned EIS and EA in 
reaching its conclusion that any marine mammals exposed to the sounds 
produced by the drillship, ice management/icebreaking vessels, support 
vessels and aircraft, and airguns would be disturbed for only a short 
period of time and would not be harmed or killed. Furthermore, the 
required mitigation and monitoring measures are expected to reduce the 
likelihood or severity of any impacts to marine mammals or their 
habitats over the course of the activities.
    Moreover, NMFS gave careful consideration to a number of other 
issues and sources of information. In particular, NMFS relied upon a 
number of scientific reports, including the 2010 U.S. Alaska Marine 
Mammal Stock Assessment Reports (SARs) to support its findings. The 
SARs contain a description of each marine mammal stock, its geographic 
range, a minimum population estimate, current population trends, 
current and maximum net productivity rates, optimum sustainable 
population levels and allowable removal levels, and estimates of annual 
human-caused mortality and serious injury through interactions with 
commercial fisheries and subsistence harvest data. NMFS also used data 
from the annual and final Bowhead Whale Aerial Survey Program (BWASP) 
and Chukchi Offshore Monitoring in Drilling Area (COMIDA) reports.
    After careful consideration of the proposed activities, the context 
in which Shell's proposed activities would occur, the best available 
scientific information, and all effects analyses (including cumulative 
effects), NMFS has determined that the specified activities: (1) Would 
not result in more than the behavioral harassment (i.e., Level B 
harassment) of small numbers of marine mammal species or stocks; (2) 
the taking by harassment would not result in more than a negligible 
impact on affected species or stocks; and (3) the taking by harassment 
would not have an unmitigable adverse impact on the availability of 
such species or stocks for taking for subsistence uses. Therefore NMFS 
has decided to issue an IHA to Shell to take, by no more than Level B 
harassment, small numbers of marine mammals incidental to its Chukchi 
Sea exploratory drilling program.
    Comment 9: The MMC recommends that NMFS require Shell to evaluate 
the source levels of the Discoverer at the proposed drilling location 
and recalculate the 120-dB re 1 [micro]Pa harassment zone and estimated 
takes, as appropriate.
    Response: As conditioned in the IHA, Shell is required to conduct 
sound source verification and characterization of the equipment to be 
used, including the drilling rig. Shell is required to report received 
levels down to 120 dB re 1 [micro]Pa. Upon completion of those tests, 
Shell will then use the new sound radii for estimating take throughout 
the season. While new take estimates will not be calculated to replace 
those in the application, Shell will use the new radii for reporting 
estimated take levels in the 90-day report.
    Comment 10: The NSB and AWL state that NMFS must consider whether 
the increase in vessel presence and vessel noise around the drill sites 
and during transit across the Arctic have the potential to disturb 
marine mammals.
    Response: Shell's application and NMFS' Notice of Proposed IHA (76 
FR 69958, November 9, 2011) outline all of the vessels intended for use 
to support the exploratory drilling program. While the application and 
proposed IHA do not include source levels or take estimates for those 
vessels, their

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presence is considered and accounted for in several of the mitigation 
measures. For example, vessel speed and maneuvering conditions apply to 
all vessels, not just the drill ship and icebreakers. Therefore, while 
NMFS contemplated the use of all vessels during activities and has 
included mitigation measures during operation of these vessels to 
reduce potentially disturbing marine mammals in the vicinity, NMFS does 
not consider the transit or operation of these vessels to rise to a 
level that would result in take.
    Comment 11: The NSB (in its 2008 letter) and AWL state that a lack 
of adequate information precludes NMFS from complying with the MMPA 
standards. AWL states that NMFS should defer all oil and gas-related 
IHAs while the necessary information is gathered.
    Response: As required by the MMPA implementing regulations at 50 
CFR 216.102(a), NMFS has used the best scientific information available 
in assessing potential impacts and whether the activity will have no 
more than a negligible impact on the affected marine mammal species or 
stock (see response to Comment 7). However, while NMFS agrees that 
there may be some uncertainty regarding behavior of animals that have 
been previously exposed to industrial sounds and how that may impact 
survival and reproduction, the best available information supports our 
findings.
    Industrial activities have been occurring (at varying rates) in the 
U.S. Arctic Ocean for decades, and the available measurable indicators 
do not suggest that these activities are having long-term impacts. For 
example, 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. Additionally, 
industry has been collecting data and conducting monitoring in the 
region for many years and will continue to do so under this IHA. 
Therefore, NMFS has determined that a negligible impact finding is 
rational.
    Comment 12: AWL and the NSB (in its 2008 letter) note that Shell's 
activities have the potential to result in serious injury. AWL also 
states that in the proposed IHA, NMFS conflated two different 
regulatory provisions governing the issuance of IHAs when it stated 
that for there to be the potential for serious injury or mortality an 
activity must be ``reasonably expected or likely'' to result in serious 
injury or mortality. AWL's letter states: ``There is no indication that 
NMFS considered the dire consequences of a spill when determining 
whether the `potential' for serious harm exists * * * Applying the 
proper standard, NMFS cannot conclude that Shell may proceed with an 
IHA.''
    Response: As analyzed in the proposed IHA, NMFS has determined that 
Shell's activities are not likely to result in injury, serious injury, 
or mortality. The activities for which Shell is authorized to take 
marine mammals would most likely result in behavioral harassment. The 
mitigation and monitoring measures analyzed in the proposed IHA and 
required in the authorization are designed to ensure the least 
practicable impact on marine mammals and their habitat and the 
availability of marine mammals for subsistence uses.
    AWL cites to NMFS' definition of ``negligible impact'' to argue 
that the agency has improperly conflated separate regulatory standards. 
``Negligible impact is 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'' (50 CFR 216.103).
    NMFS believes its decision-making should be informed by whether 
impacts are actually reasonably likely to occur. This principle is 
recognized in multiple contexts, and this does not represent the 
conflation of separate regulatory standards (in this instance, 
``negligible impact'' and ``potential to result in serious injury or 
mortality''). It is well recognized in the cases interpreting NEPA. For 
example see Ground Zero Ctr. for Non-Violent Action v. United States 
Dept of the Navy, 383 F.3d 1082, 1090-91 (9th Cir. 2004) (concluding 
that where Navy had concluded that risk was extremely remote, ``such 
remote possibilities do not in law require environmental evaluation.'') 
As explained later in this document, this interpretation reflects NMFS' 
longstanding practice of issuing IHAs in cases where the agency found 
that the potential for serious injury or mortality was ``highly 
unlikely'' (See 73 FR 40512, 40514, July 15, 2008; 73 FR 45969, 45971, 
August 7, 2008; 73 FR 46774, 46778, August 11, 2008; 73 FR 66106, 
66109, November 6, 2008; 74 FR 55368, 55371, October 27, 2009). 
Interpreting ``potential'' to include impacts with any probability of 
occurring (i.e., speculative or extremely low probability events) would 
be administratively unworkable and inconsistent with Congressional 
intent. NMFS' proposed IHA considered the risks of an oil spill in its 
analysis and used that analysis to make the final determinations here.
    Comment 13: BOEM asks that NMFS clarify how Shell will avoid 
violating condition 3(b) in the IHA, which specifies that take of any 
species not listed in the IHA is prohibited and that such take ``may 
result in the modification, suspension or revocation'' of the IHA, 
given that Shell will be flying marine mammal monitoring flights below 
1,500 ft (457 m) in areas where walrus or polar bears might be present.
    Response: NMFS only has the authority to prescribe IHA conditions 
on species for which it has jurisdiction. Both the walrus and the polar 
bear are managed by the U.S. Fish and Wildlife Service (USFWS). 
Therefore, condition 3(b) does not refer to those two species. 
Moreover, NMFS' requirement to conduct marine mammal monitoring aerial 
surveys does not preclude Shell from complying with more stringent 
restrictions and conditions imposed by other Federal agencies. NMFS' 
IHA states that flights cannot be flown below 1,500 ft (457 m) except 
in certain circumstances. The IHA does not require that the flights 
must be flown below 1,500 ft (457 m) in those circumstances.
    Comment 14: BOEM notes that the draft IHA does not provide limits 
of incidental take to species nor require Shell to not exceed those 
limits. BOEM recommends that NMFS clarify to what extent Shell would or 
should monitor/report their incidental take on a more regular basis so 
to not exceed a specified authorized incidental take prior to 
submission of the draft 90-day report.
    Response: Table 8 in the Notice of Proposed IHA (76 FR 69958, 
November 9, 2011) outlined the levels of proposed take. The final table 
of the authorized take levels is included as an attachment to the 
issued IHA. Additionally, the IHA also includes a condition requiring 
Shell to submit daily marine mammal observation logs to NMFS.

Marine Mammal Impact Concerns

    Comment 15: The MMC recommends that NMFS require Shell to collect 
all new and used drilling muds and cuttings and either reinject them or 
transport them to an Environmental Protection Agency licensed 
treatment/disposal site outside the Arctic. The NSB and AWL also note 
that Shell should be required to have a near zero discharge policy in 
the Chukchi Sea, similar to what Shell will employ in the Beaufort Sea, 
in order to ensure the least practicable impact to marine mammals, 
their habitat, and subsistence hunters.

[[Page 27326]]

    Response: Shell's collection of drilling mud and cuttings and 
certain other waste streams is a voluntary decision on the part of the 
company for its Beaufort Sea exploratory drilling program. Shell will 
not be conducting such a program in the Chukchi Sea, a practice that is 
consistent with both the current Arctic Oil and Gas Exploration General 
Permit and the draft General Permit being considered by the U.S. 
Environmental Protection Agency. The discharge of drilling related 
effluents has been extensively studied in both temperate and Arctic 
regions (Neff, 2010) and, when employing water based muds, is generally 
considered to be of slight environmental impact. The removal of muds, 
cuttings, and other effluent streams from exploration drilling requires 
additional vessels, which results in additional vessel traffic and 
related noise (which can in turn increase the potential for vessel-
marine mammal interactions and vessel-related air emissions). Given the 
concerns raised with respect to the cumulative impacts of vessel 
traffic in the Arctic, the speculative benefits of waste stream removal 
do not warrant imposing such a requirement on Shell in the Chukchi Sea. 
Shell will, however, collect water and other samples in both seas 
before, during, and after the drilling programs in order to study 
sediment and water chemistry, the biotic community, deposition, and 
bioaccumulation. The collection of these samples will repeat 
evaluations at the localized drill sites that have been conducted as 
part of the Joint Industry Monitoring Program for several years. NMFS 
has determined that even without requiring such a measure, Shell's 
activities will have a negligible impact on marine mammal species or 
stocks and will not have an unmitigable adverse impact on the 
availability of marine mammals for taking for subsistence uses.
    Comment 16: AWL states that NMFS' uniform marine mammal harassment 
thresholds do not consider documented reactions of specific species in 
the Arctic to much lower received levels. The letter notes reactions of 
bowhead and gray whales to certain activities emitting impulse sounds 
below 160 dB and of beluga and bowhead whales and harbor porpoise 
reacting to other sound sources below 120 dB. The letter also states: 
``At a minimum, any final IHA cannot apply thresholds that fail to 
accurately capture potential marine mammal harassment, as required by 
the standards imposed by the MMPA.'' Similarly, Dr. Bain notes marine 
mammal reactions, and especially those of beluga whales and harbor 
porpoises, to sounds below NMFS' 160 dB and 120 dB thresholds.
    Response: For continuous sounds, such as those produced by drilling 
operations and during icebreaking activities, NMFS uses a received 
level of 120-dB (rms) to indicate the onset of Level B harassment. For 
impulsive sounds, such as those produced by the airgun array during the 
ZVSP surveys, NMFS uses a received level of 160-dB (rms) to indicate 
the onset of Level B harassment. Therefore, while a level of 160-dB was 
used to estimate take for a portion of the operations that will only 
occur for a total of 10-56 hours, depending on how many wells are 
drilled, during the entire 4-month open-water season, a threshold of 
120-dB was used to estimate potential takes for all species from the 
drilling operations and ice management/icebreaking activities.
    While some published articles indicate that certain marine mammal 
species may avoid seismic airguns (an impulsive sound source) 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 21.7 mi (35 km) from the seismic 
source vessel, it should be pointed out that these minor course changes 
are during migration and 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 a sound pressure level (SPL) of 
160 dB. Therefore, while bowheads may avoid an area of 12.4 mi (20 km) 
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 does not consider that deviation to 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).
    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 reaction would be considered a take. According to experts on 
marine mammal behavior, whether a particular stressor could potentially 
disrupt the migration, breathing, nursing, breeding, feeding, or 
sheltering, etc., of a marine mammal, i.e., whether it would result in 
a take, 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: 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). The 120-dB and 160-dB acoustic 
criteria are generalized thresholds based on the available data that is 
intended to assist in the accurate assessment of take while 
acknowledging that sometimes animals will respond at received levels 
below that and sometimes they will not respond in a manner considered a 
take at received levels above 120 dB.
    Comment 17: AWL notes that there is a lack of information regarding 
bowhead aggregations and feeding in the area. ``Given the lack of 
information, the proposed IHA should not simply assume that the 
`closest primary feeding ground' is near Point Barrow.'' They state 
that there is evidence of bowheads frequenting the area around Point 
Franklin. Dr. Bain also states that excluding whales from feeding areas 
effectively reduces the carrying capacity, which in turn reduces the 
rate of population increase and is equivalent to removing individuals 
from the population; therefore, a shift in feeding locations would not 
be harmless.
    Response: Most bowhead whales will be in the Canadian Beaufort Sea 
when Shell begins operations in July. The fall westward migration 
begins in late August/early September through the Beaufort Sea and then 
into the Chukchi Sea. The Barrow area is commonly used as a feeding 
area during spring and fall, with a higher proportion of photographed 
individuals displaying evidence of feeding in fall rather than spring 
(Mocklin, 2009). A bowhead whale feeding ``hotspot'' (Okkonen et al., 
2011) commonly forms on the western Beaufort Sea shelf off Point Barrow 
in late summer and fall. Favorable conditions concentrate euphausiids 
and copepods, and bowhead whales congregate to exploit the dense prey 
(Ashjian et al., 2010,

[[Page 27327]]

Moore et al., 2010; Okkonen et al., 2011). Bowheads will reach this 
feeding ground in the fall prior to entering the area ensonified by 
Shell's Chukchi Sea operations. Although Shell will be conducting a 
similar operation in the Camden Bay area of the Beaufort Sea, whales 
that begin their migration into U.S. waters earlier in the season, will 
avoid sounds from Shell's operations, as activities will cease in the 
Beaufort Sea on August 25 until the close of the fall hunts at Kaktovik 
and Cross Island.
    The COMIDA 2008-2010 Final Report (Clarke et al., 2011) notes 
sightings of bowhead whales in the Chukchi Sea in all months that 
surveys were flown (June through November), except November. Sighting 
rates were highest in October; however, there were no specific areas 
where whales were concentrated each year (Clarke et al., 2011). All 
feeding was observed close to shore between Point Franklin and Barrow, 
Alaska, in June, July, and September of 2009 (Clarke et al., 2011), 
which is more than 65 mi (105 km) from Shell's Burger prospect. There 
were no observations of feeding in the areas near Shell's proposed 
drill sites.
    Moreover, while some whales may avoid the area around Shell's 
drilling program because of the increased sound levels while operations 
are ongoing, there has also been evidence that some bowheads continued 
feeding in close proximity to seismic sources (e.g., Richardson, 2004). 
The sounds produced by the drillship are of lower intensity than those 
produced by seismic airguns. Therefore, if animals remain in ensonified 
areas to feed, their feeding opportunity would not be missed, and they 
would be in areas where the sound levels are not high enough to cause 
injury (as discussed in greater detail later in this document). In 
accordance with NMFS' implementing regulations at 50 CFR 216.102(a), 
NMFS used the best available science to make the requisite findings for 
issuance of the IHA. That information indicates that there will not be 
concentrated feeding at the Burger prospect and that Shell's activities 
will not negatively affect bowhead feeding in the vicinity of Shell's 
proposed activities.
    Comment 18: Dr. Bain states that the increase in vessel traffic 
associated with Shell's project increases the risk of ship strike. AWL 
also notes that the risk of a vessel strike or the effects of a large 
oil spill could lead to serious injury. Additionally, missing 
information precludes full assessment of the effects of a large oil 
spill on bowheads may alter how NMFS assesses the potential for serious 
injury or death.
    Response: NMFS acknowledges that there is always some risk of a 
ship strike whenever a vessel transits the ocean. However, the IHA 
requires Shell to implement several mitigation measures applicable to 
vessel operation (e.g., speed restrictions in the presence of marine 
mammals or in inclement weather, avoiding multiple changes in direction 
when within 300 yards [274 m] of whales) to reduce further the low 
probability of a ship strike.
    Again, in accordance with NMFS implementing regulations, we used 
the best information available to assess potential impacts from an oil 
spill in the proposed IHA. NMFS' EA also assesses impacts from a large 
oil spill and incorporates information by reference from other recently 
released NEPA documents by BOEM regarding the potential for and impacts 
of a large oil spill on the marine environment. Also, please see the 
response to Comment 12 regarding the ``potential'' impact from 
activities. NMFS determined that there is not a risk of serious injury 
or death to occur from Shell's specified activity and therefore 
issuance of an IHA under the MMPA is appropriate.
    Comment 19: AWL and Dr. Bain note that potential impacts on females 
and calves merit ``special consideration,'' as they will migrate 
through the Chukchi Sea during the fall migration. NMFS must examine 
whether bowhead cow/calf pairs will suffer from Shell's activities and 
whether that could result in a greater degree of harm that would 
warrant specific mitigation measures.
    Response: NMFS discussed potential impacts to bowhead whales, 
including cow/calf pairs in the Notice of Proposed IHA (76 FR 69958, 
November 9, 2011). In the section that discussed potential impacts to 
marine mammals from the specified activity, NMFS described data from 
studies that included observations and reactions (or lack thereof) of 
cow/calf pairs to different anthropogenic activities. Mitigation 
measures are required in the IHA during vessel transits (e.g., speed 
restrictions, avoiding multiple changes in direction when within 300 
yards [274 m] of whales) through the Chukchi Sea and from shore to the 
drill sites. These measures will ensure that potential impacts are 
reduced to the lowest level practicable. Moreover, Shell will not enter 
the Chukchi Sea prior to July 1, after the conclusion of the spring 
bowhead whale migration.
    As noted earlier in this document, the fall migration westward 
through the Beaufort Sea and into the Chukchi Sea does not begin until 
late August/early September. Koski and Miller (2004) found that mother/
calf bowhead pairs were the last to enter the U.S. Beaufort Sea during 
the fall migration (typically arriving in September and lasting into 
October). Therefore, if mother/calf pairs are not arriving in the 
central Beaufort Sea until later in the migration, they would not reach 
the Chukchi Sea lease sale area until later in the season. Therefore, 
it is likely that Shell's activities will be nearing completion, if not 
already completed for the season before the majority of the mother/calf 
pairs reach that area of the Chukchi Sea.
    AWL cites to previous NMFS and BOEM documents, which include 
mitigation measures specifically applicable to bowhead cow/calf pairs. 
However, these pertained to seismic surveys or other programs in the 
Beaufort Sea. As has been noted elsewhere in this document and the 
proposed IHA, sounds produced during seismic surveys are different than 
those produced during drilling operations. It was determined that such 
measures were not necessary for these operations. Additionally, as has 
been noted for previous actions in the Chukchi Sea lease sale area, 
conducting such mitigation measures is impracticable for applicant 
implementation. Based on the fact that few cow/calf pairs are likely to 
occur within the 120-dB ensonified area of Shell's operations and the 
protection afforded by the already required mitigation measures, 
additional measures are not necessary to ensure the least practicable 
impact on bowhead cow/calf pairs.
    Comment 20: AWL states that NMFS must consider potential effects on 
beluga mothers and calves and must evaluate whether enough is known 
about beluga habitat use to accurately predict the degree of harm 
expected from Shell's operations. The proposed IHA's negligible impact 
assessment provides very little discussion of beluga whales. Moreover, 
the proposed IHA appears to rely on a population estimate for the 
Beaufort Sea stock rather than the significantly smaller Chukchi Sea 
stock even though both stocks are found in the Chukchi Sea during the 
fall. Dr. Bain also notes that work will be underway while belugas are 
nursing and caring for calves.
    Response: As noted in responses to earlier comments in this 
document, as required by the MMPA implementing regulations at 50 CFR 
216.102(a), NMFS has used the best scientific information available in 
assessing potential impacts and whether the activity will have no more 
than a negligible impact on the affected marine mammal species or 
stock. While NMFS agrees that there may be some uncertainty regarding 
spatial and temporal habitat needs of

[[Page 27328]]

belugas, the best available information supports our findings.
    While Shell's exploratory drilling program will overlap temporally 
with the beluga calving season, it will not overlap spatially. Tagging 
data from the 1990s indicates that belugas from the eastern Beaufort 
Sea stock will be in Canadian waters (i.e., Mackenzie Delta and 
Amundsen Gulf) in the summer (July and August) and do not start 
migrating through the Beaufort Sea until September but do so far 
offshore (Richard et al., 2001; DFO, 2000). In the summer months, 
belugas from the eastern Chukchi Sea stock are typically found in 
Kasegaluk Lagoon and Kotzebue Sound (Suydam et al., 2001), locations 
that are approximately 100 mi (161 km) or more south of the Burger 
prospect. Shell will transit far offshore so as not to disturb the 
summer beluga hunts conducted in Kasegaluk Lagoon and therefore will 
avoid interactions with mothers and calves. Tagging data of belugas 
from this stock have also indicated that they travel far offshore in 
the Beaufort Sea to Canadian waters later in the summer (Suydam et al., 
2001). Based on this information, it is unlikely that many beluga 
mother/calf pairs will pass within the 120-dB isopleths of Shell's 
Chukchi Sea exploratory drilling program. Mitigation and monitoring 
measures will ensure that impacts to any belugas that do occur in the 
vicinity of the program will be at the lowest level practicable.
    Comment 21: AWL states that NMFS must consider whether Shell's ice 
management efforts have the potential to seriously injure or kill 
ringed seals resting on pack ice.
    Response: NMFS considered the potential impacts of Shell's ice 
management efforts to ringed seals resting on pack ice in the Notice of 
Proposed IHA (76 FR 69958, November 9, 2011) in the section regarding 
anticipated effects on marine mammal habitat. AWL also references the 
MMS 2008 Draft EIS for the Beaufort Sea and Chukchi Sea Planning Areas 
Oil and Gas Lease Sales 209, 212, 217, and 221 (MMS, 2008), which 
includes a reference to Reeves (1998). Reeves (1998) noted that some 
ringed seals have been killed by icebreakers moving through fast-ice 
breeding areas. In the proposed IHA analysis, NMFS considered this 
information and noted that since Shell's use of the icebreakers would 
occur outside of the ringed seal breeding and pupping seasons in the 
Chukchi Sea, serious injury or mortality from use of the icebreakers 
would not occur.
    Limited ice breaking might be needed to assist the fleet in 
accessing/exiting the project area if large amounts of ice pose a 
navigational hazard. Ice seals have variable responses to ice 
management activity. Alliston (1980, 1981) reported icebreaking 
activities did not adversely affect ringed seal abundance in the 
Northwest Territories and Labrador. Brueggeman et al. (1992) reported 
ringed seals and bearded seals diving into the water when an icebreaker 
was 0.58 mi (0.93 km) away. However, Kanik et al. (1980) reported that 
ringed seals remained on sea ice when an icebreaker was 0.62-1.24 mi 
(1-2 km) away.
    The drill site is expected to be mostly ice-free during July, 
August, and September, and the need for ice management should be 
infrequent. The presence of an icebreaker is primarily a safety 
precaution to protect the drill ship from damage. Ice seals could be on 
isolated floes that may need to be managed for safety. Any ice seals on 
floes approaching the drill ship may be disturbed by ice management 
activities. Ringed seals on an ice floe are anticipated to enter the 
water before the icebreaker contacts the ice, remain in the water as 
the ice moves past the drill ship, and could reoccupy ice after it has 
moved safely past the drill ship. As was discussed in the proposed IHA, 
NMFS determined that this activity and these reactions would result in 
Level B harassment. NMFS did not determine that there was a potential 
for serious injury or morality to occur from Shell's ice management 
efforts.
    Comment 22: Dr. Bain states that noise exposure can lead to stress, 
which can impair the immune system and result in an increase in 
mortality from disease. He also notes that impairing the energy balance 
can slow growth, delay onset of sexual maturity, and increase the 
interval between successful births, all of which can cause a reduction 
in the number of animals recruited to the population.
    Response: While deflection may cause animals to expend extra 
energy, there is no evidence that deflecting around oil and gas 
exploration activities (or other anthropogenic activities) 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; Allen and Angliss, 2011). Additionally, as 
mentioned in the response to Comment 17, all feeding was observed close 
to shore between Point Franklin and Barrow, Alaska, in June, July, and 
September of 2009 (Clarke et al., 2011), which is more than 65 mi (105 
km) from Shell's Burger prospect. There were no observations of feeding 
in the areas near Shell's proposed drill sites. Regarding recruitment 
of calves to the population, the count of 121 calves during the 2001 
census was the highest yet recorded and was likely caused by a 
combination of variable recruitment and the large population size 
(George et al., 2004). The calf count provides corroborating evidence 
for a healthy and increasing population. Based on this information, 
NMFS does not expect Shell's activities to impact annual rates of 
recruitment or survival within the Western Arctic bowhead stock.
    Comment 23: Dr. Bain states that hearing loss or masking from 
exposure to high levels of noise would impair bowhead whales' ability 
to hear vocalizations. He also states that hearing loss and masking 
would increase vulnerability to predation or ship strike, which in turn 
could increase mortality.
    Response: As noted in the proposed IHA, the source level of the 
Discoverer is lower than the thresholds used by NMFS for the onset of 
auditory injury. Shutdown and power-down measures are required in the 
IHA when the airguns are in use to help reduce further the extremely 
low likelihood of temporary threshold shift (a Level B harassment). As 
noted in the proposed IHA, masking effects are anticipated to be 
limited. Annual acoustic monitoring near BP's Northstar production 
facility during the fall bowhead migration westward through the 
Beaufort Sea has recorded thousands of calls each year (for examples, 
see Richardson et al., 2007; Aerts and Richardson, 2008). To compensate 
for and reduce masking, some mysticetes may alter the frequencies of 
their communication sounds (Richardson et al., 1995a; Parks et al., 
2007). Additionally, if some individuals avoid the drilling area, 
impacts from masking will be even lower. There is no evidence to 
suggest that any masking would increase the likelihood of death.
    Comment 24: Dr. Bain states that even though the bowhead population 
increased in the face of industry activity in the 1990s, an increase in 
disturbance now (while it appears close to carrying capacity) could 
result in slowed growth or a loss of individuals.
    Response: Based on information provided in the responses to other 
comments in this section, NMFS does not agree that population growth 
would be slowed as a result of Shell's proposed activity or increase 
the numbers of individuals lost. There are no data indicating that the 
population cannot continue to grow (as it has for over a decade) in the 
face of such activities.

[[Page 27329]]

Shell's activities will occur in a small portion of the bowheads' 
range.
    Comment 25: Dr. Bain notes that masking of beluga whale 
echolocation signals by noise, and temporary and permanent threshold 
shifts will impair the ability of belugas to find food. This mechanism 
is in addition to impaired abilities to find food due to displacement 
from high quality feeding areas.
    Response: As noted in the proposed IHA, beluga whale echolocation 
signals have peak frequencies from 40-120 kHz, which are far above the 
frequency range of the sounds produced by the devices to be used by 
Shell during the Chukchi Sea exploratory drilling program. Therefore, 
those industrial sounds are not expected to interfere with 
echolocation. Additionally, the source level of the drillship is lower 
than the thresholds used by NMFS for the onset of auditory injury. 
Shutdown and power-down measures are required in the IHA when the 
airguns are in use to help reduce further the extremely low likelihood 
of temporary threshold shift (a Level B harassment). Lastly, there are 
no data indicating that the area surrounding Shell's Burger prospect is 
an important feeding area for beluga whales.

Acoustic Issues/Concerns

    Comment 26: The MMC states that it is not clear which specific 
source level was used to model the size of the corrected 120-dB re 1 
[mu]Pa harassment zone for the Discoverer, as the reported source 
levels for the Discoverer ranged from 177-185 re 1 [mu]Pa at 1 m. It 
also is not clear how the source level measurements taken in the South 
China Sea were incorporated in the model to estimate the 120-dB re 1 
[mu]Pa harassment zone in the Chukchi Sea.
    Response: The modeling analysis considered 1/3-octave band levels 
to account for frequency-dependent propagation effects that cannot 
adequately be characterized with broadband analysis. The 1/3-octave 
band source levels were obtained from dedicated measurements of the 
Frontier Discover (now Noble Discoverer) during drilling activities in 
the South China Sea. A plot showing these levels is provided in the 
response to Comment 27, and the corresponding broadband levels could be 
computed by summing those if required. The modeling approach applied by 
JASCO Applied Science was the MONM parabolic equation acoustic 
propagation model in each 1/3-octave band from 10 Hz to 2 kHz. The 
resulting received band levels were summed to compute the broadband 
received levels at many depths, distances and directions from the 
planned drillship location. Representative sound level threshold radii 
were determined by calculating the 95th percentile distance, over all 
azimuths, at which the maximum threshold over all depths was received. 
This approach considers that animals may sample multiple depths as they 
pass by the drilling operation.
    Comment 27: Dr. Bain notes that sound propagation efficiency 
depends on conditions and that the modeling used by Shell does not 
capture the most efficient mode of propagation. He also states that 
there is great uncertainty with source levels based on single 
measurement locations, as was done for the Discoverer.
    Response: The concern raised here about variability of profiles is 
addressed in the response to Comment 29. With regard to the question on 
which source levels were used for modeling, this study considered 1/3-
octave band source levels from the Discoverer drillship obtained during 
dedicated measurements performed in 2009 in the South China Sea (Austin 
and Warner, 2010). The specific levels are representative of the 
drilling operation since that activity will occur for the majority of 
time. The source levels used for the ice management vessel are from 
surrogate measurements of the Maersk Rover transiting at 25% power.
    Comment 28: Dr. Bain states that noise sources associated with 
thruster use may result in a significant increase in the ensonified 
area; however, it is unclear from the IHA application how often the 
thrusters would be used.
    Response: Shell does not intend to use thrusters as part of its 
standard operating procedure throughout the drilling season. The 
Discoverer will be anchored in place. The only time thrusters would be 
used would be in the unlikely event that the Discoverer is blown off 
location and the drillship needs to be repositioned.
    Comment 29: Dr. Bain states that the correction factor of 1.5 
applied to the distance to the 120 dB contour is inadequate to 
conservatively account for the variability.
    Response: The concern raised here is that the sound speed profile 
used for acoustic modeling of drill rig noise may not account for 
changes to the salinity and temperature profile that could influence 
and create variability in sound propagation, and the resulting 
variability might lead to conditions in which model estimates would not 
be conservative. The location-specific sound speed profiles considered 
for this modeling study were obtained from the GDEM database for 
conditions in July and October. A modeling study (Johnston et al., 
2009) investigated the difference in sound propagation for both months 
and showed longer-range sound propagation using the October profile. To 
be precautionary and to avoid underestimating the propagation, the 
modeling at the Burger prospect that was used for marine mammal effects 
assessment was conducted using the October profile (see Figure 2). 
Therefore, a correction factor of 1.5 is appropriate in this 
circumstance.
BILLING CODE 3510-22-P

[[Page 27330]]

[GRAPHIC] [TIFF OMITTED] TN09MY12.000

BILLING CODE 3510-22-C
    Comment 30: Dr. Bain notes that when multiple sources are involved, 
such as an ice management vessel and drillship, accurate 
characterization of the sound fields will be necessary to determine 
whether their sound fields overlap and whether marine mammals are 
likely to deflect around one or both sources. NMFS should perform a 
sensitivity analysis using a variety of propagation conditions.
    Response: NMFS agrees that a modeling sensitivity analysis would 
provide a measure of expected variability. However, the acoustic 
modeling study that was performed to estimate Shell's drilling noise 
effects on marine mammals relied on environmental parameters that were 
expected to lead to better sound propagation, thereby providing 
overestimates of the generated noise field. That study considered the 
combined noise emissions of a support vessel and the drillship, and it 
would be representative of drilling operations during the vast majority 
of time while active ice management was not in progress. To better 
define the true noise levels and variability, Shell designed a field 
measurement program that monitors actual drilling sounds at several 
distances and at multiple directions over the full duration of drilling 
of the first well at Shell's Burger prospect in the Chukchi Sea. This 
monitoring will continuously sample the temporal variability of noise 
propagation due to changing oceanographic conditions over approximately 
one month. NMFS determined that this approach will

[[Page 27331]]

provide a better sampling of variability than a modeling sensitivity 
study.
    Unlike the eastern Beaufort Sea, where the fall bowhead migration 
tends to occur across a relatively narrow depth/distance-from-shore 
corridor and where feeding concentrations are sometimes apparent, 
tagged bowhead whales migrate across the Chukchi over a broad area with 
little indication of concentration aside from offshore Barrow and the 
Chukotka coast (Quakenbush et al., 2010). Because the 487 active leases 
in the Chukchi Sea contain only 2% of the total probable habitat used 
by bowheads in September and only 1% in both October and November, 
there are very limited indications of significant use of the few lease 
blocks involved in this exploration drilling program. As such, the 
number of potential exposures and deflections are expected to be both 
low in number and of limited biological consequence.

Marine Mammal Biology Concerns

    Comment 31: AWL states that the Bering Sea stock of harbor porpoise 
is based on ``arbitrarily set geographic boundaries.'' AWL and Dr. Bain 
both note that the stock size is likely smaller than what is currently 
estimated and that smaller stocks tend to be more vulnerable to harm 
from human activities.
    Response: Currently, there are insufficient samples to draw 
conclusions about stock structure of harbor porpoise within Alaska. 
While NMFS acknowledges that perhaps smaller stocks should be 
recognized in Alaska, the best available science indicates that take 
from Shell's activities will potentially impact only small numbers of 
harbor porpoise and will not have a negligible impact on the affected 
species or stock. Using the current estimated stock size of 48,215 
individuals for the Bering Sea stock, only 0.03% is estimated to be 
taken by harassment. If the number should be 16,271 (as suggested by 
AWL), this would still represent less than 0.1% of the stock size. NMFS 
does not agree that just because a stock contains fewer individuals 
than originally estimated that it is far less able to tolerate takes 
than expected. Dr. Bain does not provide any scientific evidence for 
this statement.
    Comment 32: AWL and Dr. Bain note that gray whales use Hanna Shoal 
for feeding and that Shell's operations may block gray whales' access 
to this habitat or cause them to abandon their feeding. Additionally, 
they note that since its Endangered Species Act (ESA) delisting in 
1994, numbers have declined.
    Response: The COMIDA 2008-2010 Final Report (Clarke et al., 2011) 
notes 504 sightings of 835 gray whales during that time period, which 
were seen in every month of surveys each of the 3 years (i.e., June to 
November) between Wainwright and Barrow within 31 mi (50 km) of shore. 
Clarke et al. (2011) note that sightings were also scattered throughout 
the study area more than 31 mi (50 km) offshore. The relative lack of 
gray whale sightings (and mud plumes, which are indicative of the 
presence of feeding gray whales) offshore was markedly different from 
that documented during surveys conducted from 1982-1991, when gray 
whales were frequently seen on Hanna Shoal (Moore and Clarke, 1992 
cited in Clarke et al., 2011). Gray whale sightings were most common in 
the survey blocks closer to shore in all months (Clarke et al., 2011). 
Based on this information, it appears that currently nearshore 
locations are being used more frequently than Hanna Shoal for feeding 
by gray whales. Shell's operations (which are located more than 65 mi 
[105 km] from shore) are not expected to block gray whales' access to 
feeding grounds closer to shore. Additionally, even though it might 
require a slight deflection or deviation from the migration path, gray 
whales wanting to access the Hanna Shoal area would be able to do 
during Shell's operations.
    Since 1994, NMFS has continued to monitor the status of the 
population consistent with its responsibilities under the ESA and the 
MMPA. In 1999, a NMFS review of the status of the eastern North Pacific 
stock of gray whales recommended the continuation of this stock's 
classification as non-threatened (Rugh et al., 1999). Workshop 
participants determined the stock was not in danger of extinction, nor 
was it likely to become so in the foreseeable future.
    In 2001, several organizations and individuals petitioned NMFS to 
re-list the eastern North Pacific gray whale population. NMFS concluded 
that there were several factors that may be affecting the gray whale 
population, but there was no information indicating that the population 
may be in danger of extinction or likely to become so in the 
foreseeable future. The population size of the Eastern North Pacific 
(ENP) gray whale stock has been increasing over the past several 
decades despite an unusual mortality event in 1999 and 2000. The 
estimated annual rate of increase, based on the unrevised abundance 
estimates between 1967 and 1988, is 3.3% with a standard error of 0.44% 
(Buckland et al., 1993); using the revised abundance time series from 
Laake et al. (2009) leads to an annual rate of increase for that same 
period of 3.2% with a standard error of 0.5% (Punt and Wade, 2010). 
Prior to the revised abundance estimates of Laake et al. (2009), Wade 
(2002) conducted an assessment of the ENP gray whale stock using survey 
data through 1995-96. Wade and Perryman (2002) updated the assessment 
in Wade (2002) to incorporate the abundance estimates from 1997-1998, 
2000-2001, and 2001-2002, as well as calf production estimates from the 
northward migration (1994 to 2001), into a more complete analysis that 
further increased the precision of the results. All analyses concluded 
that the population was within the stock's optimum sustainable 
population level (i.e., there was essentially zero probability that the 
population was below the stock's maximum net population level), and 
estimated the population in 2002 was between 71% and 102% of current 
carrying capacity. NMFS continues to monitor the abundance of the stock 
through the MMPA stock assessment process, especially as it approaches 
its carrying capacity. If new information suggests a reevaluation of 
the ENP gray whales' listing status is warranted, NMFS will complete 
the appropriate reviews.
    Comment 33: AWL states that any final IHA must analyze potential 
effects of all of Shell's operations on ribbon, ringed, spotted, and 
bearded seals and must do so considering the distinct habitats and life 
histories for each. AWL also notes that portions of the ringed and 
bearded seal populations are proposed for listing under the ESA and 
that those listings were prompted, in part, by the effects of climate 
change on ice seal habitat. The added stress of diminishing habitat 
should be considered in NMFS' analysis here.
    Response: NMFS has considered the potential effects of Shell's 
activities on all four ice seal species in the context of the distinct 
habitats and life histories for each. In the proposed IHA, NMFS 
acknowledged the importance of sea ice to various life functions, such 
as breeding, pupping, and resting. Several of these species perform 
these functions on sea ice outside of the project area. Shell's 
activities would occur at a time of year when the ice seal species 
found in the region are not molting, breeding, or pupping. Therefore, 
these important life functions would not be impacted by Shell's 
activities. NMFS' EA for this action considers the impacts of climate 
change on ice seals in the region.
    Comment 34: AWL notes the recent outbreak of skin lesions and sores 
among ringed seals. The letter states that

[[Page 27332]]

NMFS should consider the weakened state of the population as part of 
the analysis. They also note that some spotted and bearded seals have 
shown symptoms as well.
    Response: NMFS began receiving reports of the outbreak in summer 
2011 and declared an unusual mortality event in December 2011. An 
investigative team was established, and testing has been underway. 
Testing has ruled out numerous bacteria and viruses known to affect 
marine mammals, including Phocine distemper, influenza, Leptospirosis, 
Calicivirus, orthopoxvirus, and poxvirus. Foreign animal diseases and 
some domestic animal diseases tested for and found negative include 
foot and mouth disease, VES, pan picornavirus, and Rickettsial agents. 
Last month, preliminary radiation testing results were announced which 
indicate radiation exposure is likely not a factor in the illness. 
Further quantitative radionuclide testing is occurring this spring. 
Results will be made publicly available as soon as the analyses are 
completed.
    Reports from the NSB indicate that hunters during early winter 
observed many healthy bearded and ringed seals. The seals behaved 
normally: They were playful, curious but cautious, and maintained 
distance from boats. No lesions were observed on any seals. During 
December 2011 and January 2012, 20-30 adult ringed seals were harvested 
from leads in the sea ice in the NSB. Based on local reports, these 
seals had neither hair loss nor lesions. However, during late February 
2012, a young ringed seal with nodular and eroded flipper lesions but 
no hair loss was harvested. Additionally, necropsy results of the 
internal organs were consistent with animals with this disease that 
continues to affect ice seals in the NSB and Bering Strait regions. 
Chukotka hunters did not report any sightings or harvest of sick and/or 
hairless seals in December 2011 and January 2012.
    NMFS has considered this information as part of its analysis in 
making the final determinations for this IHA. The data available to 
date do not indicate that this has weakened the population. Moreover, 
Shell's activities are anticipated to take less than 1% of the 
population of all of the stocks of all three species noted by the 
commenter. The sound that will be produced by Shell's activities is of 
a low level. Therefore, even if the population were weakened from this 
outbreak it would not change our evaluation of the impacts of this 
activity at the population level.
    Comment 35: Dr. Bain states the population censuses for the eastern 
Chukchi Sea and Beaufort Sea stocks of belugas have not been conducted 
in the last 10 years and that population trends are unknown. No 
evidence of population growth was seen when censuses were still being 
conducted.
    Response: In accordance with NMFS' implementing regulations at 50 
CFR 216.102(a), NMFS used the best available science to make the 
requisite findings for issuance of the IHA. That science indicates that 
only small numbers of belugas will be taken and that those incidental 
takings will have no more than a negligible impact on the affected 
beluga stocks and will not have an unmitigable adverse impact on the 
availability of those belugas for taking for subsistence uses.

Density and Take Estimate Concerns

    Comment 36: The AEWC, NSB, AWL, and Dr. Bain state that using a 
strict density approach to estimate take is unreasonable, as it does 
not account for the movement of animals through the drilling area 
during the time period over which the activities will occur. The NSB 
states that this approach likely results in take estimates that are 
biased low. The AEWC and Dr. Bain suggest that NMFS should draw a line 
across the ensonified area and estimate the number of marine mammals 
that would be expected to cross that line during Shell's activities.
    Response: During migration, there are clear changes in the density 
of animals that pass through a particular area of ocean, and ``take'' 
estimates attempt to consider this. In other situations, it is 
difficult to account for the movements of individuals within a 
relatively small area of ocean. Using densities provides the best 
estimate of animals though it assumes that animals are distributed 
evenly in the environment, which is not correct. This approach has, 
however, been used for most statistical approaches to dealing with 
animals in such situations, and NMFS has determined it is the 
appropriate and most robust approach in this case. In most cases, it 
overestimates the number of animals actually ``taken'' by the 
activities because it assumes no avoidance of the area by individuals.
    Other approaches to estimate take were explored, mostly notably 
application of Quakenbush et al. (2010), which produced similar low 
estimates. Application of probability of occurrence within a specific 
portion of an area as large as the Chukchi Sea over a period of a month 
is not the equivalent of estimating occurrence distribution along a 
cross transect of a migration. Quakenbush et al. (2010) do indicate 
that use of the central Chukchi area by bowhead whales during the fall 
is low (2% of the total probability of occurrence in September and 1% 
of the total probability of total occurrence in both October and 
November). Because Shell's exploration drilling would occur in only 
three of the 487 active leases in the Chukchi Sea, take estimates do 
not differ appreciably from those based upon density. Unless data from 
Quakenbush et al. (2010) are reanalyzed across narrow bands of the 
migration corridor, using density estimates provides a reliable method 
for estimating take.
    Comment 37: The NSB and AWL note that the modeled 120-dB isopleths 
for the Discoverer are different in the Beaufort and Chukchi Seas (with 
the isopleth being slightly smaller in the Chukchi Sea). Additionally, 
they question if the 120-dB isopleth for the Discoverer is correct 
given its nearly identical source level to the Kulluk drill rig 
(proposed for use in the Beaufort Sea), for which sound propagates out 
to the 120-dB isopleth at a much farther distance. If the modeled 
propagation is incorrect for the Discoverer, then this would bias the 
take estimates low.
    Response: The primary reason for the difference in the distance of 
the 120-dB isopleths for the Discoverer in the Beaufort Sea vs. the 
Chukchi Sea is due to differences in the geoacoustic parameters for the 
two seas that were input to the model. Water depth, seabed density, and 
seabed sound speed are generally the most important parameters that 
influence sound propagation.
    Differences in sound propagation from the two rigs are real and are 
caused by differences in the design of the two vessels. While the 
broadband source levels for the Discoverer and Kulluk may be similar, 
their spectral properties differ considerably. Acoustic modeling 
considers the source levels in 1/3-octave frequency bands. Figures 3 
and 4 show the band levels for both drillships during drilling. Of key 
importance are the significantly lower levels of the Discoverer in the 
50 to 500 Hz bands that propagate well in the relatively shallow waters 
of these drilling operations. While the Discoverer apparently has 
higher band levels below 50 Hz, this energy is more rapidly attenuated 
than higher frequency sound energy. This characteristic of sound 
propagation in shallow waters leads to predominantly mid-frequency 
sounds (50-500 Hz) dominating the acoustic field at distance from the 
drillships. A further consideration is that the Kulluk source levels 
are known to include contributions from support vessels, and much of 
the mid-high frequency band

[[Page 27333]]

energy in its source levels may not originate entirely from the 
drillship itself, as acknowledged by Greene (1987). The Discoverer 
source level measurements by Austin and Warner (2010) were made at 
closer distances and do not include significant contributions from 
other vessels. Additionally, the IHA requires Shell to conduct sound 
source verification and characterization tests on all equipment used.
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BILLING CODE 3510-22-C
    Comment 38: AWL notes that any final IHA must assess exactly when 
Shell's ice management/icebreaking will occur and also consider the 
effects of both ice management vessels operating simultaneously but at 
some distance apart. Because the fall migration through the Chukchi Sea 
can last late into October, any ice management during the fall could 
affect a large number of whales.
    Response: Because it cannot be predicted with absolute certainty as 
to when ice may be present in the area that could pose a risk to 
drilling operations, it is difficult to state with absolute certainty 
when Shell's ice management/icebreaking will occur. Using data on 
Arctic sea ice presence from recent years, Shell estimated the most 
likely times that such activities would be required. Shell will also 
implement an Ice Management Plan (IMP) to ensure real-time ice and 
weather forecasting is conducted in order to identify conditions that 
might put operations at risk and will modify activities accordingly. 
The description of Shell's activities in the proposed IHA indicated 
that both ice management vessels could be operating simultaneously at 
different locations and was considered in the analysis.
    Comment 39: Dr. Bain states that density estimates for harbor 
porpoise may be low since Shell determined densities based on industry 
vessel-based counts.
    Response: No published densities or data on survey efforts or 
sightings were available for harbor porpoise, but estimates had been 
calculated from

[[Page 27334]]

industry survey data from 2006-2008, so those densities were used. The 
commenter is correct that the industry vessels did not conduct standard 
randomized line-transect surveys while operating (except for short 
periods in 2006). However, this information was considered the best 
scientific information available to determine a density estimate for 
harbor porpoise in the Chukchi Sea. NMFS reviewed the COMIDA 2008-2010 
Final Report to see if newer data were available, but the report notes 
that harbor porpoise were not sighted (Clarke et al., 2011), likely due 
to their small size, making it difficult to positively identify them 
from the aircraft.

Subsistence Use Concerns

    Comment 40: The AEWC and ICAS state that they have expressed 
concerns about direct impacts to the subsistence hunts resulting from 
deflection of bowhead whales by vessel traffic and underwater noise, as 
well as from icebreaking and geophysical exploration. The letters note 
that concerns about direct and indirect threats to hunting arise from 
discharge and associated impacts on water quality, the risk of an oil 
spill, and the cumulative impacts from the sum of all commercial and 
industrial activities occurring in our waters. Under the MMPA, NMFS has 
an obligation to ensure that any proposed activities do not have an 
unmitigable adverse impact on our subsistence activities.
    Response: NMFS analyzed the potential impacts from the activities 
noted here in the proposed IHA and the EA. Potential impacts to the 
availability of marine mammals for subsistence uses were included in 
those analyses. Based on the mitigation measures contained in the IHA 
to ensure the availability of marine mammals for subsistence uses, NMFS 
determined that Shell's activities would not have an unmitigable 
adverse impact on the availability of marine mammal species or stocks 
for taking for subsistence uses. Additionally, Shell worked 
independently with the AEWC to develop and sign a CAA, which also 
includes measures to reduce impacts to bowhead whaling from their 
drilling operations and other activities.
    Comment 41: The AEWC states that whaling has resumed in Wainwright, 
Point Hope, and Point Lay and that these communities have been 
allocated a quota to use for the fall hunt. The AEWC asks that NMFS 
correct the information in the notice and carry forward this 
information into all future analyses. The letter also states that NMFS' 
``analysis should consider the specific timing and location of 
subsistence hunting for each community as compared to the specific 
timing and location of Shell's proposed operations.'' Lastly, the AEWC 
states that NMFS did not include a preliminary finding regarding 
whether or not Shell's activities would have an unmitigable adverse 
impact on the fall hunt in the Chukchi villages and must publish this 
preliminary finding for comment.
    Response: NMFS used the updated information on fall hunting 
activities in the communities of Wainwright, Point Hope, and Point Lay 
in the Draft EA (NMFS, 2012) that was released for public comment and 
has also updated that information in this analysis and will use it in 
all future analyses. NMFS' analysis considered both location and timing 
of subsistence hunting activities, as well as location and timing of 
Shell's operations. Lastly, NMFS is not required to publish a 
preliminary finding regarding ``no unmitigable adverse impact to the 
availability of marine mammals for subsistence uses'' at the proposed 
IHA stage. The MMPA implementing regulations indicate that NMFS will 
publish any preliminary finding of ``negligible impact'' or ``no 
unmitigable adverse impact'' for public comment along with the proposed 
IHA if preliminary findings have been made at that time. 50 CFR 
216.104(c). In this instance, at the proposed IHA stage NMFS was still 
evaluating the available information and believed it would be 
beneficial to review information and comments submitted by the public 
before making determinations regarding whether Shell's proposed action 
will have a negligible impact on the affected species or stocks of 
marine mammals and no unmitigable adverse impact on the availability of 
such species or stocks for taking for subsistence uses. Based on our 
review, we have made the requisite findings of small numbers, 
negligible impact, and no unmitigable adverse impact on the 
availability of the taking of marine mammals for subsistence uses.
    Comment 42: The AEWC expressed concern about potential impacts to 
the subsistence hunt in the Bering Sea communities from end of season 
transits. Because the proposed IHA noted that Shell's IHA expires on 
October 31, they believe that this is adequate, at this time, to 
prevent any conflicts with Bering Sea communities so long as Shell 
begins transit towards the Bering Strait on October 31. The AEWC 
requests that NMFS consider late season transits to Bering Sea 
communities in all future Federal Register notices regarding IHAs for 
oil and gas activities in the Arctic. Shell should have plans in place 
to communicate with those communities if, for whatever reason, its 
ships are delayed in the leaving the Chukchi Sea.
    Response: Shell signed the 2012 CAA with the AEWC on March 26, 
2012. In the signed 2012 CAA, Shell agreed to establish Communication 
Centers in the Bering Sea communities and will conduct such 
communications in the manner laid out in the CAA. Shell's IHA is valid 
for drilling operations through October 31. Therefore, demobilization 
and transit out of the area must begin by that date. Information shared 
with NMFS from hunters on St. Lawrence Island in 2011 noted that the 
fall bowhead whale hunts typically occur the week of Thanksgiving. 
Shell will begin to demobilize and transit south towards Dutch Harbor 
beginning on October 31, and will avoid being in the area when hunters 
from Gambell and Savoonga (on St. Lawrence Island) are actively hunting 
bowhead whales.
    Comment 43: The AEWC states that they are concerned about the 
potential for cumulative impacts to subsistence activities if Shell 
transits vessels back and forth between the Chukchi Sea and Beaufort 
Sea drill sites. The AEWC asks that NMFS specify whether and to what 
extent vessel traffic between the two locations is predicted, what 
impact that may have on the hunt at Barrow, and whether this vessel 
traffic may combine with deflection from the Beaufort Sea drill sites 
to create a large impact on the bowhead migration.
    Response: Shell's Beaufort and Chukchi exploration drilling 
programs are designed and resourced to be independent and self 
sufficient. With the exception of the vessels that would be transiting 
for the purpose of supporting a spill response (in the unlikely event 
that one occurs), it is not expected that there will be regular 
transits of vessels related to Chukchi operations into, or out of, the 
Beaufort theater of operation.
    BOEM included the following condition within its approval of 
Shell's Chukchi Exploration Plan: ``If Shell transits to the Chukchi 
Sea from the Beaufort Sea during the fall bowhead whale migration and 
before or during Barrow's fall bowhead whale subsistence hunt, Shell 
shall meet with the appropriate whaling captains to coordinate vessel 
transit routes westward through the Beaufort Sea to prevent any 
deflection of the bowhead whale migration and any conflicts with 
Barrow's fall whaling season. Emergency operations will take precedence 
over this condition.''
    This condition is consistent with existing commitments made by 
Shell to

[[Page 27335]]

consult with subsistence hunters prior to and during vessel transits 
and other operations. Vessel transit and communication with subsistence 
hunters are addressed in the signed 2012 CAA. Shell will fund the 
operation of communication centers in each of the coastal communities 
throughout the period of exploration activities in the Chukchi Sea. 
Vessels will report their position and projected transit route and 
schedule to these communication centers every 6 hours. Information 
provided to these communication centers will be available to AEWC and 
other subsistence co-management organizations and to subsistence 
hunters within the communities for the purpose of supporting the 
avoidance or reduction of conflicts between industry and subsistence 
activities. Shell will also operate a network of Subsistence Advisors 
within each of the coastal communities. The role of the Subsistence 
Advisors is to actively consult with local hunters on a daily basis, to 
be aware of typical patterns of subsistence resource movements and 
behavior and patterns of subsistence harvest, to inform Shell of any 
potential for conflicts, and to aid in the adaptive resolution of 
potential for conflicts. Based on the fact that vessel transit between 
the two programs would only occur in extreme and unlikely 
circumstances, it is not anticipated that there will be additional 
impacts beyond those analyzed here.
    Comment 44: The MMC states that negotiating and completing a CAA 
related to bowhead whales is useful but also prompts the question as to 
why such agreements are not being developed with subsistence hunters 
taking other species that might be affected by oil and gas operations. 
With that in mind, the MMC recommends that NMFS issue the requested IHA 
but also facilitate the development of CAAs that involve all 
potentially affected communities and co-management organizations and 
take into account all potential adverse effects on all marine mammal 
species taken for subsistence purposes including, but not limited to, 
bowhead whales.
    Response: 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 to some 
extent beluga) whales, the signing of it is not a requirement. 
Regulations promulgated pursuant to the 1986 MMPA amendments require 
that for an activity that will take place near a traditional Arctic 
hunting ground, or may affect the availability of marine mammals for 
subsistence uses, an applicant for MMPA authorization must either 
submit a POC or information that identifies the measures that have been 
taken to minimize adverse impacts on subsistence uses. Shell submitted 
a POC with its IHA application, which was available during the public 
comment period. Additionally, as indicated earlier in this document, 
Shell signed the 2012 CAA with the AEWC on March 26, 2012.
    NMFS (or other Federal agencies) has no authority to require 
agreements between third parties, and NMFS would not be able to enforce 
the provisions of CAAs because the Federal government is not a party to 
the agreements. Regarding the CAA signed with the AEWC, NMFS has 
reviewed that document, as well as Shell's POC. The majority of the 
conditions are identical between the two documents. NMFS has also 
included measures from the 2012 CAA between Shell and the AEWC relevant 
to ensuring no unmitigable adverse impact on the availability of marine 
mammals for subsistence uses. NMFS has also determined that the 
measures in the POC related to species other than the bowhead whale are 
sufficient to ensure no unmitigable adverse impact on the availability 
of those species for subsistence uses.
    In the recently released Draft EIS on the Effects of Oil and Gas 
Activities in the Arctic Ocean (NMFS, 2011), NMFS began to examine both 
the CAA and POC processes. There are strengths and weaknesses in how 
both processes are currently executed. NMFS is committed to working 
with the AEWC, Alaska Beluga Whale Committee, and Ice Seal Committee 
and other stakeholders to improve upon and combine these processes, as 
appropriate.
    Comment 45: The NSB appreciates Shell's effort to mitigate impacts 
to the bowhead hunt; however, Shell's proposed activities may adversely 
impact subsistence hunting of other species in the Chukchi Sea. 
Mitigation measures are needed to protect eastern Chukchi Sea belugas 
and beluga hunters. Restricting transit through the Chukchi Sea until 
the hunt is completed at Point Lay would be an effective measure. NMFS 
must also evaluate impacts to seals from the transit of vessels 
associated with Shell's planned activities and how that may impact seal 
hunts.
    Response: In the proposed IHA, NMFS evaluated potential impacts to 
subsistence hunts of all species in the project area. Ringed seals are 
typically hunted from October through June, which is outside the time 
frame of Shell's operations. Although spotted and bearded seal hunts 
may overlap temporally with Shell's operations, the hunting grounds are 
located much closer to shore than where Shell will operate. When Shell 
conducts supply vessel and other transits between shore and the drill 
sites, Shell is required to implement mitigation measures to avoid 
unmitigable adverse impacts to subsistence hunts, including using the 
Communication Centers to find out about the timing and location of 
active hunting.
    NMFS understands the NSB's concerns regarding vessel transit and 
how that may affect hunts in the Chukchi Sea communities, especially 
the summer beluga hunt at Point Lay. Shell has committed to transiting 
offshore of the hunt and to communicating with Point Lay via the 
Communication Center regarding vessel transits to ensure that they 
remain outside of the hunting areas. These measures were part of 
Shell's POC and are included in the IHA. Therefore, NMFS has determined 
that there will not be an unmitigable adverse impact on the 
availability of beluga whales and ice seals for taking for subsistence 
uses.

Mitigation and Monitoring Concerns

    Comment 46: Shell states that the 1,500 ft (457 m) flight altitude 
restriction mitigation measure applies to all ``non-marine mammal 
observation'' flights, thus allowing for observer flights to fly lower 
as needed to afford the best possible marine mammal sightings and 
identifications.
    Response: NMFS concurs. The measure was written in two different 
ways in several parts of the proposed IHA. One way only exempted 
takeoffs, landings, and emergency situations from the 1,500 ft (457 m) 
altitude restriction, while in other parts of the document marine 
mammal monitoring flights were also exempted. NMFS has eliminated the 
discrepancy in the final IHA. The exemption now applies to takeoffs, 
landings, emergency situations, and marine mammal monitoring flights.
    Comment 47: The MMC recommends that NMFS require Shell to develop 
and employ a more effective means to monitor the entire corrected 120-
dB re 1 [mu]Pa harassment zone for the presence and movements of all 
marine mammals and for estimating the actual number of takes, including 
aerial and acoustic surveys of the proposed drilling sites before, 
during, and after drilling operations. The NSB and AWL also

[[Page 27336]]

recommend that NMFS require Shell to fly aerial surveys in the area of 
the offshore drill sites.
    Response: Shell's original monitoring plan included an acoustic 
component to record both equipment sounds and marine mammal 
vocalizations. Since submitting that monitoring plan, Shell has 
modified it to include an offshore aerial component. Shell will conduct 
a photographic aerial survey in 2012, which will serve as a pilot study 
for future surveys that could use an Unmanned Aerial System to capture 
the imagery. The proposed photographic surveys in the Chukchi and 
Beaufort Seas would collect data that will allow direct comparisons of 
photographic techniques for data collection with data collected by 
human observers aboard the aircraft in the Beaufort Sea. Additional 
details on the photographic survey can be found in Shell's revised 
monitoring plan (see ADDRESSES).
    While the 120-dB harassment zone from the drill rig will likely 
extend beyond what the observers can effectively see from the drill 
rig, Shell will place Protected Species Observers (PSOs) on all vessels 
used for the drilling operations. Many of these vessels will be located 
several kilometers from the drill rig, thus expanding the visual 
observation zone. Moreover, Shell will supplement its vessel-based 
operations with marine mammal aerial observations, thus expanding the 
visual observation zone. PSOs will be stationed on the vessels to 
observe from the best vantage points available and will be equipped 
with ``Big-eyes'' and other binoculars to aid in detection. 
Additionally, NMFS does not contend that PSOs will be able to see every 
marine mammal within the harassment zone. Using the vessel-based and 
aerial platforms to detect and count marine mammal sightings and then 
to use those observations in conjunction with sightings from other 
surveys such as COMIDA is reasonable for estimating maximum take.
    Comment 48: The MMC recommends that NMFS track and enforce Shell's 
implementation of mitigation and monitoring measures to ensure that 
they are executed as expected.
    Response: During Shell's operating season, NMFS will meet weekly 
with staff from BOEM, the Bureau of Safety and Environmental 
Enforcement (BSEE), and the USFWS to review and analyze proprietary 
operations reports, including PSO logs to ensure environmental and 
regulatory compliance. Additionally, BSEE will have inspectors on the 
drilling platform 24 hours a day/7 days a week.
    Comment 49: The NSB, MMC, and AWL state that NMFS should require 
Shell to make monitoring data available to the public. The NSB states 
that in addition to the monitoring data, locations and activities of 
drill rigs, icebreakers, and support vessels should also be made 
publicly available.
    Response: In accordance with an agreement between NOAA, Shell, 
ConocoPhillips, and Statoil, data from Shell sponsored science and 
monitoring efforts and from those that are jointly funded by the 
signatory parties will be made available to NOAA and to the public. The 
manner of release, format of released data, site(s) of data repository, 
and rights of data use are currently being addressed by a working 
group. Public access to these data is being addressed through this 
process and would not be enhanced by conditions imposed through the 
IHA.
    Shell has committed to the support and operation of communication 
centers in Kaktovik, Nuiqsut, Barrow, Wainwright, Point Lay, Point 
Hope, Kivalina, Kotzebue, St. Lawrence Island, and Wales. As required 
by the CAA (which Shell signed on March 26, 2012), all Shell vessels 
operating in the Beaufort and Chukchi Sea will contact the nearest 
communication center every 6 hours and provide the following 
information:
    (A) Vessel name, operator of vessel, charter or owner of vessel, 
and the project the vessel is working on;
    (B) Vessel location, speed, and direction; and
    (C) Plans for vessel movement between the time of the call and the 
time of the next call. The final call of the day will include a 
statement of the vessel's general area of expected operations for the 
following day, if known at that time.
    The vessels will also contact the nearest communications center in 
the event that operations change significantly from those projected 
during the prior 6 hour reporting period. The communication centers 
will be generally open and available to the public and will provide a 
capability for direct communications between subsistence hunters and 
Shell vessels. Shell will operate these centers for the entire duration 
of operations in the Chukchi and Beaufort Seas, rather than limiting 
operations to the periods of the bowhead subsistence hunt.
    Since 2010, NMFS has required operators in the Arctic to provide 
vessel tracks during the season as a part of the required 90 day 
report. Given that the potentially impacted public are provided with 
multiple avenues with which they can acquire vessel location and 
activity data, and that vessel tracks will be made available to the 
general public at the end of the season, there is no additional need 
for real-time public access to vessel location information. Further, 
given that there are current and legitimate concerns with respect to 
security of vessels, crew, and operations, public access to vessel 
locations and activities may not be in the best interest of safe marine 
operations.

Cumulative Impact Concerns

    Comment 50: The MMC noted that it is important to consider that 
some of the animals may already be in a compromised state as a result 
of climate disruption, stochastic variation in food resources, or 
variation in physiological state due to normal life history events 
(e.g., molting or reproduction in pinnipeds).
    Response: In the Notice of Proposed IHA (76 FR 69958, November 9, 
2011), NMFS considered others factors, including when pinnipeds and 
cetaceans conduct varying life history functions and whether or not 
those activities overlap in time and space with Shell's Chukchi Sea 
exploratory drilling program. Pupping and breeding for some ice seals 
do not occur in the Chukchi Sea. Pupping of ringed and bearded seals, 
which do build subnivean lairs in the Chukchi Sea, occurs outside of 
Shell's operating timeframe in the Chukchi Sea. Additionally, in the EA 
for this action, NMFS analyzed impacts of other activities and factors, 
such as climate disruption. Based on this information, NMFS determined 
that Shell's activities would have no more than a negligible impact on 
the affected marine mammal species or stocks.
    Comment 51: Dr. Bain states that cumulative effects are of concern 
and that the drilling in the Chukchi Sea cannot be considered 
separately from other planned activities, including similar activities 
by Shell in the Beaufort Sea, as well as work proposed by other 
companies. Further, if exploratory drilling results in future 
production, the cumulative effect of production in the core of the 
migration route needs to be considered.
    Response: NMFS analyzed the combination of both of Shell's proposed 
2012 drilling programs in its EA, as well as other seismic exploration 
and vessel transportation in the Beaufort and Chukchi Seas. 
Additionally, NMFS' response to Comment 8 explains how other factors 
were taken into consideration when analyzing this proposal under the 
MMPA. Because it is unknown if Shell will successfully find

[[Page 27337]]

oil during its exploratory drilling program, it is premature and 
speculative to discuss potential impacts from building a production 
facility in the Chukchi Sea. If Shell finds oil, it would be several 
years before construction of a production facility would begin. 
Additional environmental analyses would be required at that time.

ESA Statutory Concerns

    Comment 52: AWL and BOEM note that NMFS should consider ringed and 
bearded seals in the ESA section 7 consultation.
    Response: The Notice of Proposed IHA (76 FR 69958, November 9, 
2011) for this action noted that NMFS would initiate ESA section 7 
consultation for bowhead, humpback, and fin whales. However, NMFS has 
included ringed and bearded seals in the Biological Opinion prepared 
for this action, which analyzes effects to ESA-listed species, as well 
as species proposed for listing.
    Comment 53: AWL states that the conclusions reached in NMFS' 2008 
and 2010 Biological Opinions for oil and gas activities in the Arctic 
regarding effects of oil spills must be reconsidered.
    Response: NMFS' Office of Protected Resources Permits and 
Conservation Division requested consultation under section 7 of the ESA 
with the NMFS Alaska Regional Office Endangered Species Division. A new 
Biological Opinion has been prepared for this IHA. In April, 2012, NMFS 
finished conducting its section 7 consultation and issued a Biological 
Opinion, and concluded that the issuance of the IHA associated with 
Shell's 2012 Chukchi Sea drilling program is not likely to jeopardize 
the continued existence of the endangered bowhead, humpback, and fin 
whale, the Arctic sub-species of ringed seal, or the Beringia distinct 
population segment of bearded seal. No critical habitat has been 
designated for these species, therefore none will be affected.
    Comment 54: BOEM recommends that NMFS consult with USFWS regarding 
the effects of the proposed action on resources under USFWS 
jurisdiction, including the compatibility of the joint industry 
research program that NMFS continues to require in IHAs with existing 
ESA section 7 consultation between BOEM and USFWS.
    Response: NMFS has determined that issuance of the IHA to Shell 
will not affect species under USFWS jurisdiction and that formal 
consultation is not required. However, NMFS strives to work closely 
with other Federal agencies and would welcome any specific suggestions 
from BOEM or USFWS on future IHAs that would help to achieve 
coordinated and complementary mitigation and monitoring measures.

NEPA Statutory Concerns

    Comment 55: The AEWC and NSB states that NMFS must include 
information regarding upcoming oil and gas activities planned for the 
Beaufort and Chukchi Seas in 2012 in U.S., Russian, and Canadian 
waters, as well as reasonably foreseeable future drilling activities. 
Both letters request that NMFS develop a method for assessing impacts 
from multiple drilling operations and to ascertain the significance of 
multiple exposures to underwater noise, ocean discharge, and air 
pollution and vessel traffic.
    Response: NMFS' EA contains information on upcoming activities in 
U.S., Russian, and Canadian waters for the 2012 season, as well as 
reasonably foreseeable future drilling activities in the project area. 
The EA qualitatively describes how marine mammals could be impacted 
from multiple activities in a given season and what the results of 
those exposures might be.
    Comment 56: NSB states that NMFS should be required to prepare an 
EIS, not an EA, to adequately consider the potentially significant 
impacts of the proposed IHAs, including the cumulative impacts of 
Shell's proposed activities.
    Response: NMFS' 2012 EA was prepared to evaluate whether 
significant environmental impacts may result from the issuance of IHAs 
to Shell for the take of marine mammals incidental to conducting 
exploratory drilling programs in the U.S. Beaufort and Chukchi Seas, 
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 57: The NSB states that NMFS should consider the cumulative 
impact of discharge and whether bioaccumulation of contaminants could 
have lethal or sub-lethal effects on bowhead whales and other marine 
mammals. NMFS should then synthesize that information into a health 
impact assessment looking at the overall combined effect to the health 
of the local residents.
    Response: As explained by the Council on Environmental Quality, an 
EA is a concise document and should not contain long descriptions or 
detailed data which the agency may have gathered. Rather, it should 
contain a brief discussion of the need for the proposal, alternatives 
to the proposal, the environmental impacts of the proposed action and 
alternatives, and a list of agencies and persons consulted. See NEPA's 
Forty Most Asked Questions, 46 FR 18026 (March 23, 1981); 40 CFR 
1508.9(b). The EA prepared for this action contains a discussion of 
water quality, including contaminants, in sections 3.1.5.2 and 4.2.1.5 
and incorporates additional material by reference. It also notes that 
contaminants have the potential to bioaccumulate in marine mammals, but 
that monitoring has shown that oil and gas developments in the Alaskan 
Beaufort Sea ``are not contributing ecologically important amounts of 
petroleum hydrocarbons and metals to the near-shore marine food web of 
the area'' (EA at 4.2.2.3). Given that the studies done so far have 
detected no bioaccumulation of contaminants as a result of oil and gas 
activity in the Beaufort Sea, it is only a remote and highly 
speculative possibility that discharges from Shell's exploration 
drilling program could contribute to cumulative impacts from 
contaminants that could ultimately result in health impacts to local 
residents. Agencies are not required to consider such remote or 
speculative impacts in an EA (see Ground Zero Ctr. for Non-Violent 
Action v. United States Dept of the Navy, 383 F.3d 1082, 1090 (9th Cir. 
2004)). However, NMFS acknowledges the importance of this issue to 
residents of the NSB, and has included a more extensive discussion of 
environmental contamination and its potential effects in the Draft EIS 
on Effects of Oil and Gas Activities in the Arctic Ocean (NMFS, 2011).
    Comment 58: AWL states that it would be illegal for NMFS to approve 
the IHA without completing the EIS that is in progress. NSB also states 
that it would be shortsighted to allow Shell to proceed on a 1-year IHA 
when the impacts could negatively affect arctic resources and preclude 
options that could be developed in the forthcoming EIS.
    Response: While the Final EIS is still being developed, NMFS 
conducted a thorough analysis of the affected environment and 
environmental consequences from exploratory drilling in the Arctic in 
2012 and prepared an EA specific to the two exploratory drilling 
programs proposed to be conducted by Shell. The analysis contained in 
that EA warranted a FONSI.
    The analysis contained in the Final EIS will apply more broadly to 
multiple Arctic oil and gas operations over a period of five years. 
NMFS' issuance of IHAs to Shell for the taking of several

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species of marine mammals incidental to conducting its exploratory 
drilling operations in the Beaufort and Chukchi Seas in 2012, as 
analyzed in the EA, is not expected to significantly affect the quality 
of the human environment. Additionally, the EA contained a full 
analysis of cumulative impacts.
    Comment 59: BOEM requests that NMFS' EA fully evaluate the 
potential for the NMFS-required, periodic low-level aerial marine 
mammal surveys and vessel operations to impact marine and coastal 
resources within the Ledyard Bay Critical Habitat Unit (LBCHU) and 
adjacent areas. BOEM recommends that NMFS require observation reports 
to include the location and altitude of the aircraft at the time of 
each marine mammal observation and that NMFS require observations of 
marine and coastal birds using a systematic survey protocol during any 
NMFS-required vessel entries into the LBCHU, as well as requiring that 
these vessels not approach flocks of eiders and that vessel routing be 
the shortest distance within the LBCHU.
    Response: NMFS' EA analyzes the impacts of all aspects of Shell's 
activities on all relevant resources in the area. Shell and its 
representatives maintain frequent communication with the Federal 
Aviation Administration and USFWS during the period included in the 
Chukchi aerial surveys program. During this time all notices to 
aviators are noted and observed, e.g. notices related to avoidance of 
Pacific walrus haul outs. The aerial flights either avoid flying 
through these areas, or move to a higher altitude when in close 
proximity to concentrations of sensitive resources. The aircraft also 
implements mitigation measures, such as changing the flight path or 
altitude, when the observers on board detect concentrations of 
sensitive resources or the presence of subsistence hunters.
    The altitude and position of the aircraft during survey and transit 
and from vessels during transit are available from the flight and 
vessel tracks. Flight altitudes of 1,000 ft (305 m) or greater are of 
limited value for identification and counting of marine birds. Aerial 
overflights routinely increase their altitude to 1500 ft (457 m) when 
flying over the Ledyard Bay area during surveys along the Chukchi Sea 
coast (rather than the 1000 ft [305 m] altitude flown in other parts of 
the survey) to avoid disturbance of waterfowl that might be in the 
area. Any required vessel entries to the LBCHU have included survey 
protocols to record concentrations of seabirds, particularly eiders and 
to avoid such areas if concentrations were noted. However, because the 
IHA is issued pursuant to the MMPA, NMFS does not have the authority to 
include measures related to non-marine mammal species.

Oil Spill Concerns

    Comment 60: The NSB and MMC state that Shell's application and 
NMFS' Notice of Proposed IHA (76 FR 68974, November 7, 2011) do not 
contain adequate information regarding effects of a major oil spill. 
The MMC notes that NMFS is too dismissive of the potential for a large 
oil spill. The NSB requests clarification on how NMFS considers the 
risk of an oil spill when issuing MMPA authorizations for exploratory 
drilling activities, and contends that NMFS must analyze the potential 
harm to marine mammals and subsistence activities. The NSB also states 
that Shell's application lacks any information about potential take 
resulting from a release of oil in any amount.
    Response: NMFS' Notice of Proposed IHA contained information 
regarding measures Shell has instituted to reduce the possibility of a 
major oil spill during its operations, as well as potential impacts on 
cetaceans and pinnipeds, their habitats, and subsistence activities 
(see 76 FR 69976-69980, 69984, 70004, November 7, 2011). NMFS' EA also 
contains an analysis of the potential effects of an oil spill on marine 
mammals, their habitats, and subsistence activities. Much of that 
analysis is incorporated by reference from other NEPA documents 
prepared for activities in the region. There is no information 
regarding potential take from a release of oil because an oil spill is 
not a component of the ``specified activity.''
    DOI's BOEM and BSEE are the agencies with expertise in assessing 
risks of an oil spill. In reviewing Shell's Chukchi Sea Exploration 
Plan and Regional OSRP, BOEM and BSEE determined that the risk was low 
and that Shell will implement adequate measures to minimize the risk. 
Shell's OSRP identifies the company's prevention procedures; estimates 
the potential discharges and describes the resources and steps that 
Shell would take to respond in the unlikely event of a spill; and 
addresses a range of spill volumes, ranging from small operational 
spills to the worst case discharge calculations required to account for 
the unlikely event of a blowout. Additionally, NOAA's Office of 
Response and Restoration reviewed Shell's OSRP and provided input to 
DOI requesting changes that should be made to the plan before it should 
be approved. Shell incorporated NOAA's suggested changes, which 
included updating the trajectory analysis and the worst case discharge 
scenario. Based on these revisions, NOAA Ocean Service's Office of 
Response and Restoration believes that Shell's plans to respond to an 
offshore oil spill in the U.S. Arctic Ocean are satisfactory, as 
described in a memorandum provided to NMFS by the Office of Response 
and Restoration. Lastly, in the unlikely event of an oil spill, Shell 
will conduct response activities in accordance with NOAA's Marine 
Mammal Oil Spill Response Guidelines.
    Comment 61: The MMC notes that the risk of an oil spill is not 
simply a function of its probability of occurrence; it also must take 
into account the consequences if such a spill occurs. Those 
consequences are, in part, a function of the spill's characteristics 
and the ability of the industry and government to mount an effective 
response. The MMC states: ``The assertion that Shell would be able to 
respond adequately to any kind of major spill is simply unsupported by 
all the available evidence.'' The MMC asserts that the OSRP is still 
inadequate for addressing a large oil spill in the Arctic.
    Response: As noted in the response to Comment 60, DOI approved 
Shell's OSRP on February 17, 2012. That approval came after an 
extensive review process, and changes were made to the plan based on 
comments from DOI, NOAA, and other Federal agencies. The plan calls for 
Shell to have several response assets near the drill sites for 
immediate response, while also having additional equipment available 
for quick delivery, if needed. DOI will also continue to provide 
oversight, with exercises, reviews, and inspections. NMFS' EA and 
recent BOEM NEPA analyses assess impacts to the environment from an oil 
spill.
    Comment 62: The MMC recommends that NMFS require Shell to cease 
drilling operations in mid- to late September to reduce the possibility 
of having to respond to a large oil spill in ice conditions. AWL also 
states that NMFS should consider restrictions on late-season drilling.
    Response: NMFS has not included such a measure in its IHA. In 
December 2011, BOEM conditionally approved Shell's Chukchi Sea 
Exploration Plan. One of the conditions of that approval is a measure 
designed to mitigate the risk of an end-of-season oil spill by 
requiring Shell to leave sufficient time to implement cap and 
containment operations as well as significant clean-up before the onset 
of sea ice, in the event of a loss of well control. Given current 
technology and weather

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forecasting capabilities, Shell must cease drilling into zones capable 
of flowing liquid hydrocarbons 38 days before the first-date of ice 
encroachment over the drill site. In a press release issued by BOEM on 
December 16, 2011, the agency noted that based on a five-year analysis 
of historic weather patterns, BOEM anticipates November 1 as the 
earliest anticipated date of ice encroachment. The 38-day period would 
also provide a window for the drilling of a relief well, should one be 
required. However, Shell will be permitted to continue other 
operations, such as ZVSP surveys, after that date.
    Comment 63: The MMC recommends that NMFS require Shell to develop 
and implement a detailed, comprehensive and coordinated Wildlife 
Protection Plan that includes strategies and sufficient resources for 
minimizing contamination of sensitive marine mammal habitats and that 
provides a realistic description of the actions that Shell can take, if 
any, to respond to oiled or otherwise affected marine mammals. The plan 
should be developed in consultation with Alaska Native communities 
(including marine mammal co-management organizations), state and 
Federal resource agencies, and experienced non-governmental 
organizations.
    Response: As noted in the response to Comment 60, Shell will 
operate any needed oil spill response activities in accordance with 
NOAA's Marine Mammal Oil Spill Response Guidelines. These guidelines 
were released to the public as part of NMFS' Programmatic EIS on the 
Marine Mammal Health and Stranding Response Program and were available 
for public review at that time. Those guidelines also underwent legal 
and peer review before being released. Those guidelines are currently 
being updated based on lessons learned from the Deepwater Horizon spill 
in the Gulf of Mexico.

Proposed IHA Language Concerns

    The comments and concerns contained in this grouping relate to the 
language that was contained in the Notice of Proposed IHA (76 FR 70004-
70007, November 9, 2011) in the section titled ``Proposed Incidental 
Harassment Authorization.'' The commenters requested clarification or 
changes to some of the specific wording of the conditions that would be 
contained in the issued IHA. The referenced condition in the proposed 
IHA is noted in the comments here. Numbers of the conditions match the 
proposed IHA and may differ slightly from the issued IHA.
    Comment 64: Regarding Condition 1, Shell asks that the IHA become 
effective on July 1 instead of July 4 since the company will begin 
transiting into the Chukchi Sea on July 1 (but not before), if weather 
permits, and could therefore arrive on location at the Burger prospect 
before July 4.
    Response: NMFS has made the requested change. Changing the date 
from July 4 to July 1 does not alter any of the analyses contained in 
the proposed IHA.
    Comment 65: Regarding Condition 2, Shell asks that the language of 
the IHA not limit the incidental takings from authorized sound sources 
to those made while only on Shell lease holdings because ice management 
activities may occur beyond the lease boundaries and the continuous 
noise of the drillship may extend beyond the limits of Shell's lease 
holdings.
    Response: NMFS has retained the first sentence of Condition 2, as 
originally proposed, which states that only activities associated with 
Shell's 2012 Chukchi Sea exploration plan are covered by the IHA. 
Because the exploration plan describes the locations of activities, 
NMFS has determined that language is legally sufficient. NMFS 
understands, and did analyze, that ice management may at times occur 25 
mi (40 km) from the actual drill site. Additionally, NMFS analyzed the 
propagation and sound isopleths of the drill rig, which may attenuate 
beyond the actual lease holding itself.
    Comment 66: Regarding Condition 3(a), Shell requests that narwhal 
be included in the list of species for which incidental take is 
authorized.
    Response: As noted in the Notice of Proposed IHA (76 FR 69958, 
November 9, 2011), NMFS determined that presence of narwhal in the U.S. 
Chukchi Sea is rare and extralimital. Encounters are unlikely.
    Comment 67: Regarding Condition 4, BOEM recommends that aircraft 
associated with the marine mammal surveys be included in the list of 
sound sources for which taking is authorized.
    Response: NMFS concurs and has added aircraft to the list of sound 
sources covered by the IHA.
    Comment 68: Regarding Condition 7(a), Shell asks whether the 
response they provided to NMFS on July 29, 2011, for a definition of 
``group'' is consistent with the intent meant by NMFS in the Federal 
Register notice. As a general practice, Shell will adopt a definition 
of a group as being three or more whales observed within a 547-yd (500-
m) area and displaying behaviors of directed or coordinated activity 
(e.g., group feeding).
    Response: NMFS agrees with this definition and will add the 
following sentence to Condition 7(a): ``For purposes of this 
Authorization, a group is defined as being three or more whales 
observed within a 547-yd (500-m) area and displaying behaviors of 
directed or coordinated activity (e.g., group feeding).
    Comment 69: Shell requests that Condition 7(d) be modified to match 
with the language contained in Condition 9(f), which allows marine 
mammal monitoring flights to also fly below the 1,500-ft (457-m) 
altitude restriction. In the proposed IHA, those two conditions 
contradicted one another. BOEM also requested clarification of 
Condition 7(d).
    Response: NMFS agrees that Condition 7(d) should be rewritten to 
match Condition 9(f). The condition now reads as follows: ``Aircraft 
shall not fly within 1,000-ft (305-m) of marine mammals or below 1,500-
ft (457-m) altitude (except during marine mammal monitoring, takeoffs, 
landings, or in emergency situations) while over land or sea.''
    Comment 70: Regarding Condition 7(e), Shell asks if the length of 
daily duty restrictions included in the measure apply only to the 
drillship and ice management vessels or to all vessels, including 
smaller support vessels. Shell's view is that the remainder of support 
vessels, not included as ``sound sources,'' will have fewer observers 
than either the drillship or ice management vessels (mainly due to bunk 
space), which will be sufficient to cover marine mammal observations.
    Response: NMFS concurs that the watch requirements were meant to 
apply to the drillship and two ice management vessels. PSOs will be 
required to be stationed on the other support vessels. However, they 
will not need to be on watch 24 hours a day, as those vessels are not 
always active 24 hours a day. PSOs will need to be on watch when the 
smaller support vessels are active, such as for supply transport.
    Comment 71: BOEM recommends that Condition 7(f), or a new similar 
section focusing on aerial observations, require that marine mammal 
observation reports include the location and altitude of the aircraft 
at the time of each observation.
    Response: Aircraft altitude and location are available from the 
flight track logs. NMFS has added a requirement to include this 
information in the marine mammal sighting logs.
    Comment 72: Regarding Condition 7(f)(iv), Shell requests that the 
requirement to measure water temperature be removed as a stipulation 
under this measure given that it lacks material value to the recording 
of

[[Page 27340]]

marine observations and adherence to other more salient mitigation 
measures.
    Response: NMFS included the recording of water temperature along 
with other more salient data collection parameters in the proposed IHA 
because it was included in Shell's original monitoring plan. After 
further discussion with Shell, NMFS agrees that it is not necessary to 
record water temperature each time a marine mammal is sighted and has 
removed the requirement from the IHA.
    Comment 73: Regarding Condition 9(a), Shell notes that the 
condition should mention the Burger Prospect and not the Camden Bay 
drill sites. BOEM recommends that NMFS provide a definition of the 
polynya zone so that Shell can effectively comply with this condition.
    Response: NMFS has corrected the error and removed mention of the 
Camden Bay drill sites from the condition. NMFS does not have a 
definition of the polynya zone and does not believe it is necessary to 
include one in the IHA.
    Comment 74: Regarding Condition 10, BOEM recommends inclusion of a 
brief description of the 4MP and similar programs as a part of the 
proposed action.
    Response: NMFS has determined that such a description is 
unnecessary in the IHA, as it is described in this document and the 
associated Final EA.
    Comment 75: Regarding Condition 10(c)(i), as well as Condition 
11(a), Shell requests that NMFS include language reflecting the 
flexibility of providing the drilling sounds on a ``rolling'' basis. 
Shell states that sound source verifications for the drilling vessel 
will necessitate that recordings of the various sounds of the drilling 
program continue throughout the drilling season. Hence, all drilling 
program sounds will not be available within 5 days of initiating 
drilling. Instead, Shell volunteers to provide to NMFS a ``rolling'' 
transmission of recorded drilling program sounds throughout the 
drilling program.
    Response: NMFS concurs that a ``rolling'' transmission of sound 
signatures is appropriate based on the fact that different activities 
will be conducted at various times throughout the open-water season. In 
order to capture all of the different sound signatures and for that 
data to be transmitted to NMFS, it is not appropriate to do it all in 
the first 5 days but rather to collect the data on a real-time basis. 
Spectrograms will be calculated daily, and all information will be 
included in a weekly report that discusses the drillship and vessel 
activities that occurred during the week. Language has been included in 
the IHA to reflect this weekly reporting requirement.
    Comment 76: Regarding Condition 10(c)(ii), Shell asks that the 
phrase ``to the extent practical'' precede the last sentence of the 
measure. Shell fully intends to deploy and execute the study as 
designed. However, conditional temporal and spatial factors, such as 
ice at the locations for deployment of acoustic recorders could cause 
some recorders to not be deployed or to be deployed at alternate 
locations.
    Response: NMFS has made the requested language change to the 
condition.
    Comment 77: Regarding Condition 11(d), Shell requests that the IHA 
stipulate that the comprehensive report be due 240 days from the end of 
the drilling season instead of 240 days from the date of issuance, 
since the IHA is being issued months before the start of the program.
    Response: NMFS agrees and has rewritten the condition to state that 
the comprehensive report is due 240 days from the date of expiration of 
the IHA (i.e., 240 days from October 31, 2012).

Description of Marine Mammals in the Area of the Specified Activity

    The Chukchi Sea supports a diverse assemblage of marine mammals, 
including: Bowhead, gray, beluga, killer, minke, humpback, and fin 
whales; harbor porpoise; ringed, ribbon, spotted, and bearded seals; 
narwhals; polar bears (Ursus maritimus); and walruses (Odobenus 
rosmarus divergens; see Table 4-1 in Shell's application). The bowhead, 
humpback, and fin whales are listed as ``endangered'' under the 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 
are proposed for listing under the ESA; however, none of those stocks 
or populations occur in the activity area. On December 10, 2010, NMFS 
published a notice of proposed threatened status for subspecies of the 
ringed seal (75 FR 77476) and a notice of proposed threatened and not 
warranted status for subspecies and distinct population segments of the 
bearded seal (75 FR 77496) in the Federal Register. Neither of these 
two ice seal species is considered depleted under the MMPA. 
Additionally, the ribbon seal is considered a ``species of concern'' 
under the ESA. Both the walrus and the polar bear are managed by the 
USFWS and are not considered further in this IHA notice.
    Of these species, 12 are expected to occur in the area of Shell's 
operations. These species include: The bowhead, gray, humpback, minke, 
fin, killer, and beluga whales; harbor porpoise; and the ringed, 
spotted, bearded, and ribbon seals. Beluga, bowhead, and gray whales, 
harbor porpoise, and ringed, bearded, and spotted seals are anticipated 
to be encountered more than the other marine mammal species mentioned 
here. The marine mammal species that is likely to be encountered most 
widely (in space and time) throughout the period of the drilling 
program is the ringed seal. Encounters with bowhead and gray whales are 
expected to be limited to particular seasons. Additional information 
about species occurrence in the project area was provided in the Notice 
of Proposed IHA (76 FR 69958, November 9, 2011). Where available, Shell 
used density estimates from peer-reviewed literature in the 
application. In cases where density estimates were not readily 
available in the peer-reviewed literature, Shell used other methods to 
derive the estimates. NMFS reviewed the density estimate descriptions 
and articles from which estimates were derived and requested additional 
information to better explain the density estimates presented by Shell 
in its application. This additional information was included in the 
revised IHA application. The explanation for those derivations and the 
actual density estimates are described later in this document (see the 
``Estimated Take by Incidental Harassment'' section).
    Shell's application contains information on the status, 
distribution, seasonal distribution, abundance, and life history of 
each of the species under NMFS jurisdiction mentioned in this document. 
When reviewing the application, NMFS determined that the species 
descriptions provided by Shell correctly characterized the status, 
distribution, seasonal distribution, and abundance of each species. 
Please refer to the application for that information (see ADDRESSES). 
Additional information can also be found in the NMFS Stock Assessment 
Reports (SAR). The Alaska 2010 and 2011 Draft SARs are available at: 
https://www.nmfs.noaa.gov/pr/pdfs/sars/ak2010.pdf and https://www.nmfs.noaa.gov/pr/pdfs/sars/ak2011_draft.pdf, respectively.

Brief Background on Marine Mammal Hearing

    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different

[[Page 27341]]

frequencies of sound. Based on available behavioral data, audiograms 
have been derived using auditory evoked potentials, anatomical 
modeling, and other data. Southall et al. (2007) designate ``functional 
hearing groups'' for marine mammals and estimate the lower and upper 
frequencies of functional hearing of the groups. The functional groups 
and the associated frequencies are indicated below (though animals are 
less sensitive to sounds at the outer edge of their functional range 
and most sensitive to sounds of frequencies within a smaller range 
somewhere in the middle of their functional hearing range):
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
22 kHz (however, a study by Au et al. (2006) of humpback whale songs 
indicate that the range may extend to at least 24 kHz);
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): Functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz; and
     Pinnipeds in Water: Functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
    As mentioned previously in this document, 12 marine mammal species 
(four pinniped and eight cetacean species) are likely to occur in the 
exploratory drilling area. Of the eight cetacean species likely to 
occur in Shell's project area, five are classified as low frequency 
cetaceans (i.e., bowhead, gray, humpback, minke, and fin whales), two 
are classified as mid-frequency cetaceans (i.e., beluga and killer 
whales), and one is classified as a high-frequency cetacean (i.e., 
harbor porpoise) (Southall et al., 2007). Additional information 
regarding marine mammal hearing and sound production is contained in 
the Notice of Proposed IHA (76 FR 69958, November 9, 2011).

Potential Effects of the Specified Activity on Marine Mammals

    The likely or possible impacts of the exploratory drilling program 
in the Chukchi Sea on marine mammals could involve both non-acoustic 
and acoustic effects. Potential non-acoustic effects could result from 
the physical presence of the equipment and personnel. Petroleum 
development and associated activities introduce sound into the marine 
environment. Impacts to marine mammals are expected to primarily be 
acoustic in nature. Potential acoustic effects on marine mammals relate 
to sound produced by drilling activity, vessels, and aircraft, as well 
as the ZVSP airgun array. The potential effects of sound from the 
exploratory drilling program 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., 1995a). 
However, for reasons discussed in the proposed IHA, it is unlikely that 
there would be any cases of temporary, or especially permanent, hearing 
impairment resulting from these activities.
    In the ``Potential Effects of the Specified Activity on Marine 
Mammals'' section of the Notice of Proposed IHA (76 FR 69964-69976, 
November 9, 2011), NMFS included a qualitative discussion of the 
different ways that Shell's 2012 Chukchi Sea exploratory drilling 
program may potentially affect marine mammals. That discussion focused 
on information and data regarding potential acoustic and non-acoustic 
effects from drilling activities (i.e., use of the drillship, 
icebreakers, and support vessels and aircraft) and use of airguns 
during ZVSP surveys. Marine mammals may experience masking and 
behavioral disturbance. The information contained in the ``Potential 
Effects of Specified Activities on Marine Mammals'' section from the 
proposed IHA has not changed. Please refer to the proposed IHA for the 
full discussion (76 FR 69958, November 9, 2011).

Exploratory Drilling Program and Potential for Oil Spill

    As noted above, the specified activity involves the drilling of 
exploratory wells and associated activities in the Chukchi Sea during 
the 2012 open-water season. The impacts to marine mammals that are 
reasonably expected to occur will be acoustic in nature. In response to 
previous IHA applications submitted by Shell, various entities have 
asserted that NMFS cannot authorize the take of marine mammals 
incidental to exploratory drilling under an IHA. Instead, they contend 
that incidental take can be allowed only with a letter of authorization 
(LOA) issued under five-year regulations because of the potential that 
an oil spill will cause serious injury or mortality.
    There are two avenues for authorizing incidental take of marine 
mammals under the MMPA. NMFS may, depending on the nature of the 
anticipated take, authorize the take of marine mammals incidental to a 
specified activity through regulations and LOAs or annual IHAs. See 16 
U.S.C. 1371(a)(5)(A) and (D). In general, regulations (accompanied by 
LOAs) may be issued for any type of take (e.g., Level B harassment 
(behavioral disturbance), Level A harassment (injury), serious injury, 
or mortality), whereas IHAs are limited to activities that result only 
in harassment (e.g., behavioral disturbance or injury). Following the 
1994 MMPA Amendments, NMFS promulgated implementing regulations 
governing the issuance of IHAs in Arctic waters. See 60 FR 28379 (May 
31, 1995) and 61 FR 15884 (April 10, 1996). NMFS stated in the preamble 
of the proposed rulemaking that the scope of IHAs would be limited to 
`` * * * those authorizations for harassment involving incidental 
harassment that may involve non-serious injury.'' See 60 FR 28380 (May 
31, 1995; emphasis added); 50 CFR 216.107(a). (``[e]xcept for 
activities that have the potential to result in serious injury or 
mortality, which must be authorized under 216.105, incidental 
harassment authorizations may be issued, * * * to allowed activities 
that may result in only the incidental harassment of a small number of 
marine mammals.'') NMFS explained further that applications would be 
reviewed to determine whether the activity would result in more than 
harassment, and, if so, the agency would either (1) attempt to negate 
the potential for serious injury through mitigation requirements, or 
(2) deny the incidental harassment authorization and require the 
applicant to apply for incidental take regulations. See id. at 28380-
81.
    NMFS' determination of whether the type of incidental take 
authorization requested is appropriate occurs shortly after the 
applicant submits an application for an incidental take authorization. 
The agency evaluates the proposed action and all information contained 
in the application to determine whether it is adequate and complete and 
whether the type of taking requested is appropriate. See 50 CFR 
216.104; see also 60 FR 28380 (May 31, 1995). Among other things, NMFS 
considers the specific activity or class of activities that can 
reasonably be expected to result in incidental take; the type of 
incidental take authorization that is being requested; and the 
anticipated impact of the activity upon

[[Page 27342]]

the species or stock and its habitat. See id. at 216.104(a). (emphasis 
added). Any application that is determined to be incomplete or 
inappropriate for the type of taking requested will be returned to the 
applicant with an explanation of why the application is being returned. 
See id. Finally, NMFS evaluates the best available science to determine 
whether a proposed activity is reasonably expected or likely to result 
in serious injury or mortality.
    NMFS evaluated Shell's incidental take application for its proposed 
2012 drilling activities in light of the foregoing criteria and has 
concluded that Shell's request for an IHA is warranted. Shell submitted 
information with its IHA Application indicating that an oil spill is a 
highly unlikely event that is not reasonably expected to occur during 
the course of exploration drilling or ZVSP surveys. See Chukchi Sea IHA 
Application, pp. 3 and Attachment E--Analysis of the Probability of an 
``Unspecified Activity'' and Its Impacts: Oil Spill. In addition, 
Shell's 2012 Exploration Plan indicates there is a ``very low 
likelihood of a large oil spill event.'' See Shell Offshore, Inc.'s 
Revised Outer Continental Shelf Lease Exploration Plan, Chukchi Sea, 
Alaska (May 2011), at p. 8-1; see also, Appendix F to Shell's Revised 
Outer Continental Shelf Lease Exploration Plan, at p. 4-174.
    The likelihood of a large or very large (i.e., >=1,000 barrels or 
>=150,000 barrels, respectively) oil spill occurring during Shell's 
proposed program has been estimated to be low. A total of 35 
exploration wells have been drilled between 1982 and 2003 in the 
Chukchi and Beaufort seas, and there have been no blowouts. In 
addition, no blowouts have occurred from the approximately 98 
exploration wells drilled within the Alaskan OCS (MMS, 2007a). 
Attachment E in Shell's IHA Application contains information regarding 
the probability of an oil spill occurring during the proposed program 
and the potential impacts should one occur. Based on modeling conducted 
by Bercha (2008), the predicted frequency of an exploration well oil 
spill in waters similar to those in the Chukchi Sea, Alaska, is 
0.000612 per well for a blowout sized between 10,000 barrels (bbl) to 
149,000 bbl and 0.000354 per well for a blowout greater than 150,000 
bbl. Please refer to Shell's application for additional information on 
the model and predicted frequencies (see ADDRESSES).
    Shell has implemented several design standards and practices to 
reduce the already low probability of an oil spill occurring as part of 
its operations. The wells proposed to be drilled in the Arctic are 
exploratory and will not be converted to production wells; thus, 
production casing will not be installed, and the well will be 
permanently plugged and abandoned once exploration drilling is 
complete. Shell has also developed and will implement the following 
plans and protocols: Shell's Critical Operations Curtailment Plan; IMP; 
Well Control Plan; and Fuel Transfer Plan. Many of these safety 
measures are required by the Department of the Interior's interim final 
rule implementing certain measures to improve the safety of oil and gas 
exploration and development on the Outer Continental Shelf in light of 
the Deepwater Horizon event (see 75 FR 63346, October 14, 2010). 
Operationally, Shell has committed to the following to help prevent an 
oil spill from occurring in the Chukchi Sea:
     Shell's Blow Out Preventer (BOP) was inspected and tested 
by an independent third party specialist;
     Further inspection and testing of the BOP have been 
performed to ensure the reliability of the BOP and that all functions 
will be performed as necessary, including shearing the drill pipe;
     Subsea BOP hydrostatic tests will be increased from once 
every 14 days to once every 7 days;
     A second set of blind/shear rams will be installed in the 
BOP stack;
     Full string casings will typically not be installed 
through high pressure zones;
     Liners will be installed and cemented, which allows for 
installation of a liner top packer;
     Testing of liners prior to installing a tieback string of 
casing back to the wellhead;
     Utilizing a two-barrier policy; and
     Testing of all casing hangers to ensure that they have two 
independent, validated barriers at all times.
    NMFS has considered Shell's proposed action and has concluded that 
there is no reasonable likelihood of serious injury or mortality from 
the 2012 Chukchi Sea exploration drilling program. NMFS has 
consistently interpreted the term ``potential,'' as used in 50 CFR 
216.107(a), to only include impacts that have more than a discountable 
probability of occurring, that is, impacts must be reasonably expected 
to occur. Hence, NMFS has regularly issued IHAs in cases where it found 
that the potential for serious injury or mortality was ``highly 
unlikely'' (See 73 FR 40512, 40514, July 15, 2008; 73 FR 45969, 45971, 
August 7, 2008; 73 FR 46774, 46778, August 11, 2008; 73 FR 66106, 
66109, November 6, 2008; 74 FR 55368, 55371, October 27, 2009).
    Interpreting ``potential'' to include impacts with any probability 
of occurring (i.e., speculative or extremely low probability events) 
would nearly preclude the issuance of IHAs in every instance. For 
example, NMFS would be unable to issue an IHA whenever vessels were 
involved in the marine activity since there is always some, albeit 
remote, possibility that a vessel could strike and seriously injure or 
kill a marine mammal. This would also be inconsistent with the dual-
permitting scheme Congress created and undesirable from a policy 
perspective, as limited agency resources would be used to issue 
regulations that provide no additional benefit to marine mammals beyond 
what can be achieved with an IHA.
    Despite concluding that the risk of serious injury or mortality 
from an oil spill in this case is extremely remote, NMFS nonetheless 
evaluated the potential effects of an oil spill on marine mammals. 
While an oil spill is not a component of Shell's specified activity, 
potential impacts on marine mammals from an oil spill are discussed in 
more detail in the Notice of Proposed IHA (76 FR 69958, November 9, 
2011) and NMFS' EA. Please refer to those documents for the discussion.

Anticipated Effects on Marine Mammal Habitat

    The primary potential impacts to marine mammals and other marine 
species are associated with elevated sound levels produced by the 
exploratory drilling program (i.e. the drillship and the airguns). 
However, other potential impacts are also possible to the surrounding 
habitat from physical disturbance and an oil spill (should one occur). 
The proposed IHA contains a full discussion of the potential impacts to 
marine mammal habitat and prey species in the project area. No changes 
have been made to that discussion. Please refer to the proposed IHA for 
the full discussion of potential impacts to marine mammal habitat (76 
FR 69958, November 9, 2011). NMFS has determined that Shell's 
exploratory drilling program is not expected to have any habitat-
related effects that could cause significant or long-term consequences 
for marine mammals or on the food sources that they utilize.

Mitigation

    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

[[Page 27343]]

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). This section 
summarizes the contents of Shell's Marine Mammal Monitoring and 
Mitigation Plan (4MP).

Operational Mitigation Measures

    Shell submitted a 4MP as part of its application (Attachment C; see 
ADDRESSES). Shell submitted a revised 4MP after they made voluntary 
changes to the plan and after the plan was reviewed by an independent 
peer review panel (see the ``Monitoring Plan Peer Review'' section for 
additional details). The revised plan is also available to the public 
(see ADDRESSES). The planned offshore drilling program incorporates 
both design features and operational procedures for minimizing 
potential impacts on marine mammals and on subsistence hunts. The 
design features and operational procedures have been described in the 
IHA and LOA applications submitted to NMFS and USFWS, respectively, and 
are summarized here. Survey design features include:
     Timing and locating drilling and support activities to 
avoid interference with the annual subsistence hunts by the peoples of 
the Chukchi villages;
     Identifying transit routes and timing to avoid other 
subsistence use areas and communicating with coastal communities before 
operating in or passing through these areas; and
     Conducting pre-season sound propagation modeling to 
establish the appropriate exclusion and behavioral radii.
    Shell indicates, and we agree, that the potential disturbance of 
marine mammals during operations will be minimized further through the 
implementation of several ship-based mitigation measures, which include 
establishing and monitoring safety and disturbance zones.
    Exclusion radii for marine mammals around sound sources are 
customarily defined as the distances within which received sound levels 
are greater than or equal to 180 dB re 1 [micro]Pa (rms) for cetaceans 
and greater than or equal to 190 dB re 1 [micro]Pa (rms) for pinnipeds. 
These exclusion criteria are based on an assumption that sounds at 
lower received levels will not injure these animals or impair their 
hearing abilities, but that higher received levels might have such 
effects. It should be understood that marine mammals inside these 
exclusion zones will not necessarily be injured, as the received sound 
thresholds which determine these zones were established prior to the 
current understanding that significantly higher levels of sound would 
be required before injury would likely occur (see Southall et al., 
2007). With respect to Level B harassment, NMFS' practice has been to 
apply the 120 dB re 1 [micro]Pa (rms) received level threshold for 
underwater continuous sound levels and the 160 dB re 1 [micro]Pa (rms) 
received level threshold for underwater impulsive sound levels.
    Shell will monitor the various radii in order to implement 
necessary mitigation measures. Initial radii for the sound levels 
produced by the Discoverer, the icebreaker, and the airguns have been 
modeled. Measurements taken by Austin and Warner (2010) indicated 
broadband source levels between 177 and 185 dB re 1 [micro]Pa rms for 
the Discoverer. Measurements of the icebreaking supply ship Robert 
Lemeur pushing and breaking ice during exploration drilling operations 
in the Beaufort Sea in 1986 resulted in an estimated broadband source 
level of 193 dB re 1 [micro]Pa rms (Greene, 1987a; Richardson et al., 
1995a). Based on a similar airgun array used in the shallow waters of 
the Beaufort Sea in 2008 by BP, the source level of the airgun is 
predicted to be 241.4 dB re 1 [micro]Pa rms. Once on location in the 
Chukchi Sea, Shell will conduct SSV tests to establish safety zones for 
the previously mentioned sound level criteria. The objectives of the 
SSV tests are: (1) to quantify the absolute sound levels produced by 
drilling and to monitor their variations with time, distance, and 
direction from the drillship; and (2) to measure the sound levels 
produced by vessels operating in support of drilling operations, which 
include crew change vessels, tugs, ice management vessels, and spill 
response vessels. The methodology for conducting the SSV tests is fully 
described in Shell's 4MP (see ADDRESSES). Please refer to that document 
for further details. Upon completion of the SSV tests, the new radii 
will be established and monitored, and mitigation measures will be 
implemented in accordance with Shell's 4MP.
    Based on the best available scientific literature, the source 
levels noted above for exploration drilling are not high enough to 
cause a temporary reduction in hearing sensitivity or permanent hearing 
damage to marine mammals. Consequently, Shell believes that mitigation 
as described for seismic activities including ramp ups, power downs, 
and shutdowns should not be necessary for drilling activities. NMFS has 
also determined that these types of mitigation measures, traditionally 
required for seismic survey operations, are not practical or necessary 
for this proposed drilling activity. Seismic airgun arrays can be 
turned on slowly (i.e., only turning on one or some guns at a time) and 
powered down quickly. The types of sound sources used for exploratory 
drilling have different properties and are unable to be ``powered 
down'' like airgun arrays or shutdown instantaneously without posing 
other risks to operational and human safety. However, Shell plans to 
use PSOs (formerly referred to as marine mammal observers) onboard the 
drillship and the various support vessels to monitor marine mammals and 
their responses to industry activities and to initiate mitigation 
measures (for ZVSP activities) should in-field measurements of the 
operations indicate that such measures are necessary. Additional 
details on the PSO program are described in the ``Monitoring and 
Reporting'' section found later in this document. Also, for the ZVSP 
activities, Shell will implement standard mitigation procedures, such 
as ramp ups, power downs, and shutdowns.
    A ramp up of an airgun array provides a gradual increase in sound 
levels and involves a step-wise increase in the number and total volume 
of airguns firing until the full volume is achieved. The purpose of a 
ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds in 
the vicinity of the airguns and to provide the time for them to leave 
the area and thus avoid any potential injury or impairment of their 
hearing abilities.
    During the ZVSP surveys, Shell will ramp up the airgun arrays 
slowly. Full ramp ups (i.e., from a cold start when no airguns have 
been firing) will begin by firing a single airgun in the array. A full 
ramp up will not begin until there has been a minimum of 30 minutes of 
observation of the 180-dB and 190-dB exclusion zones for cetaceans and 
pinnipeds, respectively, by PSOs to assure that no marine mammals are 
present. The entire exclusion zone must be visible during the 30-minute 
lead-in to a full ramp up. If the entire exclusion zone is not visible, 
then ramp up from a cold start cannot begin. If a marine mammal(s) is 
sighted within the exclusion zone during the 30-minute watch prior to 
ramp up, ramp up will be delayed until the marine mammal(s) is sighted 
outside of the applicable exclusion zone or the animal(s) is not 
sighted for at least 15 minutes for small

[[Page 27344]]

odontocetes and pinnipeds or 30 minutes for baleen whales.
    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 exclusion zone of the 
full arrays but is outside the applicable exclusion zone of the single 
source. If a marine mammal is sighted within the applicable exclusion 
zone of the single energy source, the entire array will be shutdown 
(i.e., no sources firing). The same 15- and 30-minute sighting times 
described for ramp up also apply to starting the airguns again after 
either a power down or shutdown.
    Additional mitigation measures include: (1) Reducing speed and/or 
changing course if a whale is sighted within 300 yards (274 m) from a 
vessel; (2) reducing speed in inclement weather; (3) checking the water 
immediately adjacent to the vessel(s) to ensure that no whales will be 
injured when the propellers are engaged; (4) resuming full activity 
(e.g., full support vessel speed) only after marine mammals are 
confirmed to be outside the safety zone; (5) implementing flight 
restrictions prohibiting aircraft from flying below 1,500 ft (457 m) 
altitude (except during marine mammal monitoring, takeoffs and 
landings, or in emergency situations); and (6) keeping vessels anchored 
when approached by marine mammals to avoid the potential for avoidance 
reactions by such animals.
    Shell will also implement additional mitigation measures to ensure 
no unmitigable adverse impact on the availability of affected species 
or stocks for taking for subsistence uses. Those measures are described 
in the ``Impact on Availability of Affected Species or Stock for Taking 
for Subsistence Uses'' section found later in this document.

Oil Spill Response Plan

    In accordance with BSEE regulations, Shell has developed an OSRP 
for its Chukchi Sea exploration drilling program. A copy of this 
document can be found on the Internet at: https://www.bsee.gov/OSRP/Shell-Chukchi-OSRP.aspx. Additionally, in its POC, Shell has agreed to 
several mitigation measures in order to reduce impacts during the 
response efforts in the unlikely event of an oil spill. Those measures 
are detailed in the ``Plan of Cooperation (POC)'' section found later 
in this document. In the unlikely event of a spill, Shell has also 
agreed to operate, to the maximum extent practicable, in accordance 
with NOAA's Marine Mammal Oil Spill Response Guidelines, which are 
available on the Internet at: https://www.nmfs.noaa.gov/pr/pdfs/health/eis_appendixl.pdf. BSEE issued approval of Shell's Chukchi Sea OSRP on 
February 17, 2012. That approval was issued after review of the plan by 
BSEE in cooperation with other Federal and state agency partners, 
including NOAA. Many of the changes to the approved OSRP reflect 
comments from NOAA, such as revising the worst case discharge scenario 
and providing trajectories of the worst case discharge over a 30-day 
period instead of a 72-hour period.
    NMFS has carefully evaluated Shell'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.
    Measures to ensure availability of such species or stock for taking 
for certain subsistence uses are discussed later in this document (see 
``Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses'' section).

Monitoring and Reporting

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

Monitoring Measures

    The monitoring plan proposed by Shell can be found in the 4MP 
(Attachment C of Shell's application; see ADDRESSES). Shell's revised 
4MP is also available to the public (see ADDRESSES). The plan was 
modified based on comments received from the peer review panel (see the 
``Monitoring Plan Peer Review'' section later in this document) and 
based on voluntary changes committed to by Shell. A summary of the 
primary components of the plan can be found in the Notice of Proposed 
IHA (76 FR 69958, November 9, 2011). A shorter description is contained 
here, with only components of the 4MP that have been modified 
summarized in greater detail here.
(1) Vessel-Based PSOs
    Vessel-based monitoring for marine mammals will be done by trained 
PSOs throughout the period of drilling operations on all vessels. PSOs 
will monitor the occurrence and behavior of marine mammals near the 
drillship during all daylight periods during operation and during most 
daylight periods when drilling operations are not occurring. PSO duties 
will include watching for and identifying marine mammals, recording 
their numbers, distances, and reactions to the drilling operations. A 
sufficient number of PSOs will be required onboard each vessel and 
specifically onboard the drillship and ice management vessels to meet 
the following criteria: (1) 100% monitoring coverage during all periods 
of drilling operations in daylight; (2) maximum of 4 consecutive hours 
on watch per PSO; and (3) maximum of 12 hours of watch time per day per 
PSO. Shell anticipates that there will be provision for crew rotation 
at least every 3-6 weeks to avoid observer fatigue.
    PSOs will watch for marine mammals from the best available vantage 
point on the drillship and support vessels. Maximizing time with eyes 
on the water is strongly promoted during training and is a goal of the 
PSO program. Each ship will have voice recorders available to PSOs. 
This will allow PSOs to remain focused on the water in situations where 
a number of sightings occur together. Additionally, Shell has 
transitioned entirely to real-time electronic data recording and 
automated as much of the process as possible to minimize time spent 
recording data as opposed to focusing eyes on the water.
    PSOs are instructed to identify animals as unknown when appropriate 
rather than strive to identify an animal when there is significant 
uncertainty. Shell also asks that they provide any sightings cues they 
used and any distinguishable features of the animal even if they are 
not able to identify the animal and record it as unidentified. Emphasis 
is also placed on recording

[[Page 27345]]

what was not seen, such as dorsal features.
    PSOs will be able to plot sightings in near real-time for their 
vessel. Significant sightings from key vessels (drill rigs, ice 
management, anchor handlers and aircraft) will be relayed between 
platforms to keep observers aware of animals that may be in or near the 
area but may not be visible to the observer at any one time. Emphasis 
will be placed on relaying sightings with the greatest potential to 
involve mitigation or reconsideration of a vessel's course (e.g., large 
group of bowheads, walruses on ice). Data will also be collected to 
further evaluate night vision equipment.
(2) Coastal and Offshore Aerial Survey Programs
    In its original 4MP, Shell proposed conducting a coastal aerial 
survey program. Since drafting that original 4MP, Shell has agreed to 
conduct an offshore aerial photographic survey program. Slight changes 
to the originally proposed coastal aerial program are noted here, along 
with details on the newly included offshore photographic survey.
    Coastal Aerial Survey--Recent aerial surveys of marine mammals in 
the Chukchi Sea were conducted over coastal areas to approximately 23 
mi (37 km) offshore in 2006-2008 and 2010 in support of Shell's summer 
seismic exploration activities. These surveys were designed to provide 
data on the distribution and abundance of marine mammals in nearshore 
waters of the Chukchi Sea. Shell proposes to conduct an aerial survey 
program in the Chukchi Sea in 2012 that would be similar to the 
previous programs.
    The current aerial survey program will be designed to collect data 
on cetaceans but will be limited in its ability to collect similar data 
on pinnipeds because they are difficult to identify at higher 
altitudes. Shell's objectives for this program include:
     To collect data on the distribution and abundance of 
marine mammals in coastal areas of the eastern Chukchi Sea;
     To collect and report data on the distribution, numbers, 
orientation and behavior of marine mammals, particularly beluga whales, 
near traditional hunting areas in the eastern Chukchi Sea; and
     To collect marine mammal sighting data using PSOs and 
digital media and to compare the data recorded by the two methods.
    With agreement from hunters in the coastal villages, manned aerial 
surveys of coastal areas to approximately 23 mi (37 km) offshore 
between Point Hope and Point Barrow will begin in late June and will 
continue until drilling operations in the Chukchi Sea are completed. In 
past years, it has been required that no surveys be conducted in the 
southern part of the survey area until after the beluga hunt is 
confirmed to be over, which has been about mid-July. Weather and 
equipment permitting, nearshore surveys will be conducted once per week 
during this time period or more often, depending on Shell's ability to 
fly offshore (which is their first priority). A full description of 
Shell's survey procedures can be found in the 4MP of Shell's 
application (see ADDRESSES), with only pertinent changes noted next.
    Five PSOs will be aboard the aircraft during surveys. Two primary 
observers will be looking for marine mammals within 1.6 mi (2.5 km) of 
the survey track line; one at a bubble window on each side of the 
aircraft. A third person will record data, and a fourth person will 
rest and alternate with the other PSOs throughout the flight so that 
none of the primary observers are on duty for more than 2 hrs at a 
time. The fifth observer will serve as an ice observer and will record 
data pertinent to Shell's ice observation program. The sighting 
information and additional data on each sighting will be entered into a 
digital voice recorder and entered into the database after the survey 
and will be used to check the data entry during the survey.
    Offshore Aerial Photographic Survey--As an addition to the original 
May 2011 4MP, Shell will conducted an unmanned aerial photographic 
survey around the offshore drilling operations. During the 2012 field 
season, Shell will mount two cameras on the aircraft to record marine 
mammals around the Chukchi Sea drill sites. This survey will serve as a 
pilot study for future unmanned aerial systems (UAS). The photographic 
surveys in the Chukchi and Beaufort Seas would collect data that will 
allow direct comparisons of photographic techniques for data collection 
with data collected by human observers aboard the aircraft. The aerial 
survey program in the Beaufort Sea will provide side-by-side 
comparisons of data collected by PSOs on the survey aircraft with 
digital imagery collected at the same time by still and video cameras. 
Surveys in the Chukchi Sea will use only digital cameras when flying 
offshore but will have observers and digital data collection when the 
nearshore and coastline surveys are conducted.
    These surveys would start as soon as the ice management, anchor 
handler, and drillship are at or near the first drilling location and 
would continue throughout the drilling period until the drilling-
related vessels have left the drilling area. Therefore, surveys are 
anticipated to begin around July 3. The offshore photographic surveys 
will be flown twice a week, weather permitting. Additional details on 
the camera specifications, survey design, and data analyses can be 
found in Shell's revised April 2012 4MP (see ADDRESSES).
(3) Acoustic Monitoring
    Shell will conduct SSV tests to establish the isopleths for the 
applicable exclusion radii, mostly to be employed during the ZVSP 
surveys. In addition, Shell will deploy an acoustic ``net'' array.
    Drilling Sound Measurements--Drilling sounds are expected to vary 
significantly with time due to variations in the level of operations 
and the different types of equipment used at different times onboard 
the Discoverer. The objectives of these measurements are:
    (1) To quantify the absolute sound levels produced by drilling and 
to monitor their variations with time, distance, and direction from the 
drilling vessel;
    (2) To measure the sound levels produced by vessels operating in 
support of exploration drilling operations. These vessels will include 
crew change vessels, tugs, icebreakers, and OSRVs; and
    (3) To measure the sound levels produced by an end-of-hole ZVSP 
survey, using a stationary sound source.
    The Discoverer, support vessels, and ZVSP sound measurements will 
be performed using one of two methods, both of which involve real-time 
monitoring. Since drafting the original 4MP in 2011, Shell and NMFS 
have agreed that spectrograms will be calculated daily, and all 
information will be included in a weekly report that discusses 
drillship and vessel activities that occurred during the week.
    Vessel sound characterizations will be performed using dedicated 
recorders deployed at sufficient distance from drilling operations so 
that sound produced by those activities does not interfere. Three AMAR 
autonomous acoustic recorders will be deployed on and perpendicular to 
a sail track on which all Shell vessels will transit. The deployment 
geometry will be as shown in Figure 3 in Shell's April 2012 4MP. This 
geometry is designed to obtain sound level measurements as a function 
of distance and direction. The fore and aft directions are sampled 
continuously over longer distances to 3.1 and 6.2 mi (5 and 10 km) 
respectively, while broadside and other directions are

[[Page 27346]]

sampled as the vessels pass closer to the recorders. Additional details 
can be found in Shell's 4MP.
    Acoustic ``Net'' Array--The acoustic ``net'' array used by Shell 
during the 2006-2011 field seasons will be deployed in 2012. The array 
was designed to accomplish two main objectives:
     To collect information on the occurrence and distribution 
of marine mammals that may be available to subsistence hunters near 
villages located on the Chukchi Sea coast and to document their 
relative abundance, habitat use, and migratory patterns; and
     To measure the ambient soundscape throughout the eastern 
Chukchi Sea and to record received levels of sound from industry and 
other activities further offshore in the Chukchi Sea.
    A net array configuration similar to that deployed in 2007-2011 is 
again proposed for 2012. The basic components of this effort consist of 
autonomous acoustic recorders deployed widely across the U.S. Chukchi 
Sea through the open-water and then winter seasons. The net array 
configuration will include a regional array of 24 AMAR recorders 
deployed from July-October off the four main transect locations: Cape 
Lisburne; Point Hope; Wainwright; and Barrow (as shown in Figure 8 of 
Shell's April 2012 4MP). These will be augmented by six AMAR recorders 
deployed from August 2012-August 2013 at Hanna Shoal. Six additional 
AMAR recorders will be deployed in a hexagonal geometry at 10 mi (16 
km) from the nominal drillship location to monitor directional 
variations of drilling-related sounds and to examine marine mammal 
vocalization patterns in vicinity of drilling activities. One new 
recorder will be placed 20 mi (32 km) northwest of the drillship to 
monitor for drilling sound propagation toward the south side of Hanna 
Shoal, which acoustic and satellite tag monitoring has identified as 
frequented by walrus in August.
    Additional details on data analysis for the types of monitoring 
described here (i.e., vessel-based, aerial, and acoustic) can be found 
in the April 2012 4MP (see ADDRESSES).

Monitoring Plan Peer Review

    The MMPA requires that monitoring plans be independently peer 
reviewed ``where the proposed activity may affect the availability of a 
species or stock for taking for subsistence uses'' (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 
regulations state, ``Upon receipt of a complete monitoring plan, and at 
its discretion, [NMFS] will either submit the plan to members of a peer 
review panel for review or within 60 days of receipt of the proposed 
monitoring plan, schedule a workshop to review the plan'' (50 CFR 
216.108(d)).
    NMFS convened an independent peer review panel, comprised of 
experts in the fields of marine mammal ecology and underwater 
acoustics, to review Shell's 4MP for Exploration Drilling of Selected 
Lease Areas in the Alaskan Chukchi Sea in 2012. The panel met on 
January 5-6, 2012, and provided their final report to NMFS on January 
27, 2012. The full panel report can be viewed on the Internet at: 
https://www.nmfs.noaa.gov/pr/pdfs/permits/openwater/peer_review_report_shell_chukchi.pdf.
    NMFS provided the panel with Shell's 4MP and asked the panel to 
answer the following questions regarding the plan:
    (1) Will the applicant's stated objectives effectively further the 
understanding of the impacts of their activities on marine mammals and 
otherwise accomplish the goals stated above? If not, how should the 
objectives be modified to better accomplish the goals above?
    (2) Can the applicant achieve the stated objectives based on the 
methods described in the plan?
    (3) Are there technical modifications to the proposed monitoring 
techniques and methodologies proposed by the applicant that should be 
considered to better accomplish their stated objectives?
    (4) Are there techniques not proposed by the applicant (i.e., 
additional monitoring techniques or methodologies) that should be 
considered for inclusion in the applicant's monitoring program to 
better accomplish their stated objectives?
    (5) What is the best way for an applicant to present their data and 
results (formatting, metrics, graphics, etc.) in the required reports 
that are to be submitted to NMFS (i.e., 90-day report and comprehensive 
report)?
    Prior to meeting with the panel, Shell reviewed the final reports 
of the 2010 and 2011 peer review panels, as Shell's 2010 proposed 
drilling activities were reviewed by the 2010 panel before the program 
was ultimately cancelled, and both reports contained general 
recommendations. In its presentation to the 2012 panel, Shell discussed 
suggested modifications and revisions to the 4MP submitted to NMFS in 
September 2011 and provided to the panel for review. The panel's final 
report includes recommendations both on the contents of the September 
2011 4MP and the modifications presented at the meeting in January 
2012.
    NMFS has reviewed the report and evaluated all recommendations made 
by the panel and has determined there are several measures that Shell 
can incorporate into its 2012 Chukchi Sea exploratory drilling program 
4MP to improve it. The panel recommendations determined by NMFS that 
are appropriate for inclusion in the 2012 program have been discussed 
with Shell and are included in the IHA, as appropriate. A summary of 
the recommendations that have been incorporated into Shell's revised 
Chukchi Sea 4MP is provided next.
(1) Vessel-Based Monitoring Measures
     Within safe limits, the PSOs should be stationed where 
they have the best possible viewing. Viewing may not always be best 
from the ship bridge, and in some cases may be best from higher 
positions with less visual obstructions (e.g., flying bridge).
     The PSOs should be instructed to identify animals as 
unknown where appropriate rather than strive to identify a species if 
there is significant uncertainty.
     Sampling of the relative near[hyphen]field around 
operations must be corrected for effort to provide the best possible 
estimates of marine mammals in safety and exposure zones.
     The PSOs should maximize their time with eyes on the 
water. This may require new means of recording data (e.g., audio 
recorder) or the presence of a data recorder so that the observers can 
simply relay information to them.
     It would be useful if the PSOs or recorders have GIS 
software available to plot marine mammals sighted and vessel position 
on a real[hyphen]time basis.
     Shell should develop a plan for real[hyphen]time, 
inter[hyphen]vessel communication of animal positions when multiple 
vessels are operating in an area.
     Continued testing and development to improve marine mammal 
detection capabilities when sighting conditions are poor is needed 
(e.g., nighttime, high sea states, inclement weather).
     Apply appropriate statistical procedures for probability 
estimation of marine mammals missed based on observational data 
acquired during some period of time before and after night and fog 
events.
     Panel members made a recommendation regarding independence 
in the hiring, training, and debriefing of PSOs. In support of that 
recommendation, NMFS recommends that Shell provide its daily

[[Page 27347]]

PSO logs to NMFS throughout the operating season.
(2) Acoustic Monitoring
     If a mitigation gun is used during the stationary zero-
offset vertical seismic surveys around the drilling sites, a reduced 
duty cycle (e.g., 1 shot/min) would be appropriate.
     Once source characterization and verification measurements 
are obtained (including better resolution on directionality, as 
discussed below), propagation models should be rerun to provide better 
spatial footprints on which to base mitigation zones.
     Shell should consider the potential integration of visual 
and acoustic data from the Beaufort and Chukchi Seas monitoring 
programs and the Joint Science Program to produce estimates of bowhead, 
beluga, and walrus density using methods developed in the DECAF project 
by the Center for Research into Ecological and Environmental Modeling 
(CREEM) at the University of St. Andrews in Scotland.
(3) Presentation of Data in Reports
     It is important that the required reports are useful 
summaries and interpretations of the results of the various elements of 
the monitoring plans as opposed to merely regurgitations of all of the 
raw results. They should thus represent a first derivative level of 
summary/interpretation of the efficacy, measurements, and observations 
rather than raw data or fully processed analysis. A clear summary 
timeline and spatial (map) representation/summary of operations and 
important observations should be given. Any and all mitigation measures 
(e.g., vessel course deviations for animal avoidance, operational 
shutdown) should be summarized. Additionally, an assessment of the 
efficacy of monitoring methods should be provided.
(4) Additional Monitoring Techniques or Methodologies
     The panel noted the concern over discharges and the 
impacts that discharges may have on marine mammals and their habitats. 
While NMFS acknowledges that there may be some challenges in designing 
techniques and methodologies to study the potential impacts from 
discharges on marine mammals for the 2012 season, because Shell's 
Chukchi Sea exploratory drilling program is proposed to be a multi-year 
operation, NMFS recommends that Shell investigate ways to conduct such 
studies during the proposed operations. Perhaps there are ways to work 
with other efforts such as the Joint Industry Monitoring Program funded 
by several of the oil and gas operators in the Beaufort and Chukchi 
Seas to collect the information and data.

Reporting Measures

    The Notice of Proposed IHA (76 FR 69958, November 9, 2011) 
described the reporting requirements that would be required of Shell, 
including an SSV report, technical reports, a comprehensive report, and 
reports of sightings of injured or dead marine mammals. Please refer to 
that notice for the full description. Slight changes have been made to 
the submission of the SSV report, as described in the response to 
Comment 75 earlier in this document. Because of the nature of the 
sounds that will be produced during Shell's operations, it is more 
appropriate to have a ``rolling'' schedule of submission of sound 
signatures. Additionally, in response to a recommendation from the peer 
review panel, NMFS will receive the daily PSO sighting logs.

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 drilling program. Noise 
propagation from the drillship, associated support vessels (including 
during ice management/icebreaking if needed), and the airgun array are 
expected to harass, through behavioral disturbance, affected marine 
mammal species or stocks. Additional disturbance to marine mammals may 
result from aircraft overflights and visual disturbance of the 
drillship or support vessels. However, based on the flight paths and 
altitude, impacts from aircraft operations are anticipated to be 
localized and minimal in nature.
    The full suite of potential impacts to marine mammals from various 
industrial activities was described in detail in the ``Potential 
Effects of the Specified Activity on Marine Mammals'' section in the 
proposed IHA. The potential effects of sound from the exploratory 
drilling program 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., 1995a). NMFS estimates that 
Shell's activities will most likely result in behavioral disturbance, 
including avoidance of the ensonified area or changes in speed, 
direction, and/or diving profile of one or more marine mammals. For 
reasons discussed in the proposed IHA, hearing impairment (TTS and PTS) 
is highly unlikely to occur based on the fact that most of the 
equipment to be used during Shell's drilling program does not have 
source levels high enough to elicit even mild TTS and/or the fact that 
certain species are expected to avoid the ensonified areas close to the 
operations. Additionally, non-auditory physiological effects are 
anticipated to be minor, if any would occur at all. Finally, based on 
the required mitigation and monitoring measures described earlier in 
this document and the fact that the back-propagated source level for 
the drillship is estimated to be between 177 and 185 dB re 1 [mu]Pa 
(rms), no injury or mortality of marine mammals is anticipated as a 
result of Shell's exploratory drilling program.
    For continuous sounds, such as those produced by drilling 
operations and during icebreaking activities, NMFS uses a received 
level of 120=dB (rms) to indicate the onset of Level B harassment. For 
impulsive sounds, such as those produced by the airgun array during the 
ZVSP surveys, NMFS uses a received level of 160=dB (rms) to indicate 
the onset of Level B harassment. Shell provided calculations for the 
120=dB isopleths produced by the Discoverer and by the icebreaker 
during icebreaking activities and then used those isopleths to estimate 
takes by harassment. Additionally, Shell provided calculations for the 
160=dB isopleth produced by the airgun array and then used that 
isopleth to estimate takes by harassment. 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 
Notice of Proposed IHA (76 FR 69958, November 9, 2011). Please refer to 
those documents for the full explanation, as only a short summary is 
provided here.
    Shell requested authorization to take bowhead, gray, fin, humpback, 
minke, killer, and beluga whales, harbor porpoise, and ringed, spotted, 
bearded, and ribbon seals incidental to exploration drilling, ice 
management/icebreaking, and ZVSP activities. Additionally, Shell 
provided exposure estimates and requested takes of

[[Page 27348]]

narwhal. However, as stated previously in this document, sightings of 
this species are rare, and the likelihood of occurrence of narwhals in 
the drilling area is minimal. Therefore, NMFS has not authorized take 
for narwhals.

Basis for Estimating ``Take by Harassment''

    ``Take by Harassment'' is described in this section and was 
calculated in Shell's application by multiplying the expected densities 
of marine mammals that may occur near the exploratory drilling 
operations by the area of water likely to be exposed to continuous, 
non-pulse sounds >=120 dB re 1 [mu]Pa (rms) during drillship operations 
or icebreaking activities and impulse sounds >=160 dB re 1 [mu]Pa (rms) 
created by seismic airguns during ZVSP activities. NMFS evaluated and 
critiqued the methods provided in Shell's application and determined 
that they were appropriate to conduct the requisite MMPA analyses.
    Marine mammal densities near the operation are likely to vary by 
season and habitat, mostly related to the presence or absence of sea 
ice. Marine mammal density estimates in the Chukchi Sea have been 
derived for two time periods, the summer period covering July and 
August, and the fall period including September and October. Animal 
densities encountered in the Chukchi Sea during both of these time 
periods will further depend on the habitat zone within which the 
operations are occurring: open water or ice margin. More ice is likely 
to be present in the area of operations during the summer period, so 
summer ice-margin densities have been applied to 50 percent of the area 
that may be exposed to sounds from exploration drilling and ZVSP 
activities in those months. Open water densities in the summer were 
applied to the remaining 50 percent of the area. Less ice is likely to 
be present during the fall season, so fall ice-margin densities have 
been applied to only 20 percent of the area that may be exposed to 
sounds from exploration drilling and ZVSP activities in those months. 
Fall open-water densities were applied to the remaining 80 percent of 
the area. Since ice management/icebreaking activities would only occur 
within ice-margin habitat, the entire area potentially ensonified by 
ice management/icebreaking activities has been multiplied by the ice-
margin densities in both seasons.
    Shell notes that there is some uncertainty about the 
representativeness of the data and assumptions used in the 
calculations. To provide some allowance for the uncertainties, 
``maximum estimates'' as well as ``average estimates'' of the numbers 
of marine mammals potentially affected have been derived. 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 Shell's application and the proposed IHA. Table 6-7 in 
Shell's application indicates that the ``average estimate'' for killer, 
fin, humpback, and minke whales, harbor porpoise, and ribbon seal is 
either zero or one. Therefore, to account for the fact that these 
species listed as being potentially taken by harassment in this 
document may occur in Shell's drilling sites during active operations, 
NMFS either used the ``maximum estimates'' or made an estimate based on 
typical group size for a particular 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 percent 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 (e.g., ringed 
seals in Bengtson et al., 2005). 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., 2000).

Estimated Area Exposed to Sounds >120 dB or >160 dB re 1 [mu]Pa rms

(1) Estimated Area Exposed to Continuous Sounds >120 dB rms From the 
Drillship
    Sounds from the Discoverer have not previously been measured in the 
Arctic. However, measurements of sounds produced by the Discoverer were 
made in the South China Sea in 2009 (Austin and Warner, 2010). The 
results of those measurements were used to model the sound propagation 
from the Discoverer (including a nearby support vessel) at planned 
exploration drilling locations in the Chukchi and Beaufort seas (Warner 
and Hannay, 2011). Broadband source levels of sounds produced by the 
Discoverer varied by activity and direction from the ship but were 
generally between 177 and 185 dB re 1 [mu]Pa [middot] m rms (Austin and 
Warner, 2010). Propagation modeling at the Burger Prospect resulted in 
an estimated distance of 0.81 mi (1.31 km) to the point at which 
exploration drilling sounds would likely fall below 120 dB. The 
estimated 0.81 mi (1.31 km) distance was multiplied by 1.5 (= 1.22 mi 
[1.97 km]) as a further precautionary measure before calculating the 
total area that may be exposed to continuous sounds >=120 dB re 1 
[mu]Pa rms by the Discoverer at each drill site on the Burger Prospect 
(Table 6-3 in Shell's application and Table 1 here). Given this 
distance or radius, the total area of water ensonified to >=120 dB rms 
during exploration drilling at each drill site was estimated to be 4.6 
mi\2\ (12 km\2\). The 160-dB radius for the Discoverer was estimated to 
be approximately 33 ft (10 m). Again, because the source level for the 
drillship was measured to be between 177 and 185 dB, the 180 and 190-dB 
radii were not needed.
    The acoustic propagation model used to estimate the sound 
propagation from the Discoverer in the Chukchi Sea is JASCO Research's 
Marine Operations Noise Model (MONM). MONM computes received sound 
levels in rms units when source levels are specified also in those 
units. MONM treats sound propagation in range-varying acoustic 
environments through a wide-angled parabolic equation solution to the 
acoustic wave equation. The specific parabolic equation code in MONM is 
based on the Naval Research Laboratory's Range-dependent Acoustic 
Model. This code has been extensively benchmarked for accuracy and is 
widely employed in the underwater acoustics community (Collins, 1993).
    Changes in the water column of the Chukchi Sea through the course 
of the exploration drilling season will likely affect the propagation 
of sounds produced by exploration drilling activities, so the modeling 
of exploration drilling sounds was run using expected oceanographic 
conditions in October which are expected to support greater sound 
propagation (Warner and Hannay, 2011). Results of sound propagation 
modeling that were used in the calculations of areas exposed to various 
levels of received sounds are summarized in Table 6-3 in Shell's 
application and Table 1 here.
    Distances shown in Table 6-3 in Shell's application and Table 1 
here were used to estimate the area ensonified to >=120 dB rms around 
the drillship. All exploration drilling activities will occur at the 
Burger Prospect. The exploration drill sites assumed for summer 2012 at 
the Burger Prospect (Burger A, F, J, and V) are 3.4 to 13 mi (5.5 km to 
21 km) from each other, and wells will not be drilled

[[Page 27349]]

simultaneously. Therefore, the area exposed to continuous sounds >=120 
dB at each drill site is not expected to overlap with any other drill 
site. The total area of water potentially exposed to received sound 
levels >=120 dB rms by exploration drilling operations during July-
August at two locations is therefore estimated to be 9.42 mi\2\ (24.4 
km\2\). Activities at two additional locations in September-October may 
expose an additional 9.42 mi\2\ (24.4 km\2\) to continuous sounds >=120 
dB rms.
[GRAPHIC] [TIFF OMITTED] TN09MY12.002

(2) Estimated Area Exposed to Continuous Sounds >120 dB rms From Ice 
Management/Icebreaking Activities
    Measurements of the icebreaking supply ship Robert Lemeur pushing 
and breaking ice during exploration drilling operations in the Beaufort 
Sea in 1986 resulted in an estimated broadband source level of 193 dB 
re 1 [mu]Pa [middot] m (Greene, 1987a; Richardson et al., 1995a). 
Measurements of the icebreaking sounds were made at five different 
distances and those were used to generate a propagation loss equation 
[RL=141.4-1.65R-10Log(R) where R is range in kilometers (Greene, 
1987a); converting R to meters results in the following equation: 
R=171.4-10log(R)-0.00165R]. Using that equation, the estimated distance 
to the 120 dB threshold for continuous sounds from icebreaking is 4.74 
mi (7.63 km). Since the measurements of the Robert Lemeur were taken in 
the Beaufort Sea under presumably similar conditions as would be 
encountered in the Chukchi Sea in 2012, an inflation factor of 1.25 was 
selected to arrive at a precautionary 120 dB distance of 5.9 mi (9.5 
km) for icebreaking sounds (see Table 6-3 in Shell's application and 
Table 1 here). Additionally, measurements of identical sound sources at 
the Burger and Camden Bay prospects in 2008 yielded similar results, 
suggesting that sound propagation at the two locations is likely to be 
similar (Hannay and Warner, 2009).
    If ice is present, ice management/icebreaking activities may be 
necessary in early July and towards the end of operations in late 
October, but it is not expected to be needed throughout the proposed 
exploration drilling season. Icebreaking activities would likely occur 
in a 40[deg] arc up to 3.1 mi (5 km) upwind of the Discoverer (see 
Figure 1-3 and Attachment B in Shell's application for additional 
details). This activity area plus a 5.9 mi (9.5 km) buffer around it 
results in an estimated total area of 162 mi\2\ (420 km2) that may be 
exposed to sounds >=120 dB from ice management/icebreaking activities 
in each season.
(3) Estimated Area Exposed to Impulsive Sounds >160 dB rms From Airguns
    Shell proposes to use the ITAGA eight-airgun array for the ZVSP 
surveys in 2012, which consists of four 150-in\3\ airguns and four 40-
in\3\ airguns for a total discharge volume of 760 in\3\. The >=160 dB 
re 1 [mu]Pa rms radius for this source was estimated from measurements 
of a similar seismic source used during the 2008 BP Liberty seismic 
survey (Aerts et al., 2008). The BP liberty source was also an eight-
airgun array but had a slightly larger total volume of 880 in\3\. 
Because the number of airguns is the same, and the difference in total 
volume only results in an estimated 0.4 dB decrease in the source level 
of the ZVSP source, the 100th percentile propagation model from the 
measurements of the BP Liberty source is almost directly applicable. 
However, the BP Liberty source was towed at a depth of 5.9 ft (1.8 m), 
while Shell's ZVSP source would be lowered to a target depth of 13 ft 
(4 m) (from 10-23 ft [3-7 m]). The deeper depth of the ZVSP source has 
the potential to increase the source strength by as much as 6 dB. Thus, 
the constant term in the propagation equation from the BP Liberty 
source was increased from 235.4 to 241.4 while the remainder of the 
equation (-18*LogR--0.0047*R) was left unchanged. NMFS reviewed the use 
of this equation and the similarities between the 2008 BP Liberty 
project and Shell's proposed drilling sites and determined that it is 
appropriate to base the sound isopleths on those results. This equation 
results in the following estimated distances to maximum received 
levels: 190 dB = 0.33 mi (524 m); 180 dB = 0.77 mi (1,240 m); 160 dB = 
2.28 mi (3,670 m); 120 dB = 6.52 mi (10,500 m). The >=160 dB distance 
was multiplied by 1.5 (see Table 6-3 in Shell's application and Table 4 
here) for use in estimating the area ensonified to >=160 dB rms around 
the drilling vessel during ZVSP activities. Therefore, the total area 
of water potentially exposed to received sound levels >=160 dB rms by 
ZVSP operations at two exploration well sites during each season (i.e., 
summer and fall) is estimated to be 73.7 mi\2\ (190.8 km\2\).
    Shell intends to conduct sound propagation measurements on the 
Discoverer and the airgun source in 2012 once they are on location in 
the Chukchi Sea. The results of those measurements would then be used 
during the season to implement mitigation measures.

Potential Number of Takes by Harassment

    Although a marine mammal may be exposed to drilling or icebreaking 
sounds >=120 dB (rms) or airgun sounds >=160 dB (rms), 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. There are several variables that determine whether or not an 
individual animal will exhibit a response to the sound, such as the age 
of the animal, previous exposure to this type of anthropogenic sound, 
habituation, etc.
    Numbers of marine mammals that might be present and potentially 
disturbed (i.e., Level B harassment) are estimated below based on 
available data about mammal distribution and densities at different 
locations and times

[[Page 27350]]

of the year as described previously. Exposure estimates are based on a 
single drillship (Discoverer) drilling up to four wells in the Chukchi 
Sea from July 1-October 31, 2012. Shell assumes an average of 32 days 
at each drill site (including the partial well drill site, including 
7.5 days of MLC excavation at all four drill sites). Shell also assumes 
that ZVSP activities may occur at each well drilled. Additionally, 
Shell assumed that more ice is likely to be present in the area of 
operations during the July-August period, so summer ice-margin 
densities have been applied to 50 percent of the area that may be 
exposed to sounds from exploration drilling and ZVSP activities in 
those months. Open-water densities in the summer were applied to the 
remaining 50 percent of the area. Less ice is likely to be present 
during the September-October period, so fall ice-margin densities have 
been applied to only 20 percent of the area that may be exposed to 
sounds from exploration drilling and ZVSP activities in those months. 
Fall open-water densities were applied to the remaining 80 percent of 
the area. Since ice management/icebreaking activities would only occur 
within ice-margin habitat, the entire area potentially ensonified by 
ice management/icebreaking activities has been multiplied by the ice-
margin densities in both seasons.
    The number of different individuals of each species potentially 
exposed to received levels of continuous drilling-related sounds >=120 
dB re 1 [mu]Pa or to pulsed airgun sounds >=120 dB re 1 [mu]Pa within 
each season and habitat zone was estimated by multiplying:
     The anticipated area to be ensonified to the specified 
level in the time period and habitat zone to which a density applies, 
by
     The expected species density.
    The numbers of exposures were then summed for each species across 
the seasons and habitat zones.

Estimated Take Conclusions

    As stated previously, NMFS' practice has been to apply the 120 dB 
re 1 [mu]Pa (rms) received level threshold for underwater continuous 
sound levels and the 160 dB re 1 [mu]Pa (rms) received level threshold 
for underwater impulsive sound levels to determine whether take by 
Level B harassment occurs. However, not all animals react to sounds at 
these low levels, and many will not show strong reactions (and in some 
cases any reaction) until sounds are much stronger.
    Although the 120-dB isopleth for the drillship may seem slightly 
expansive (i.e., 1.22 mi [1.97 km], which includes the 50% inflation 
factor), the zone of ensonification begins to shrink dramatically with 
each 10-dB increase in received sound level to where the 160-dB 
isopleth is only about 33 ft (10 m) from the drillship. As stated 
previously, source levels are expected to be between 177 and 185 dB 
(rms). For an animal to be exposed to received levels between 177 and 
185 dB, it would have to be within several meters of the vessel, which 
is unlikely, especially given the fact that certain species are likely 
to avoid the area.
    For impulsive sounds, such as those produced by the airguns, 
studies reveal that baleen whales show avoidance responses, which would 
reduce the likelihood of them being exposed to higher received sound 
levels. The 180-dB zone (0.77 mi [1.24 km]) is one-third the size of 
the 160-dB zone (2.28 mi [3.67 km], which is the modeled distance 
before the 1.5 inflation factor is included). In the limited studies 
that have been conducted on pinniped responses to pulsed sound sources, 
they seem to be more tolerant and do not exhibit strong behavioral 
reactions (see Southall et al., 2007).
    NMFS has authorized the maximum take estimates provided in Table 6-
7 of Shell's application and Table 2 here. With the exception of killer 
and minke whales (which are still less than 2.5%), less than 1% of each 
species or stock would potentially be exposed to sounds above the Level 
B harassment thresholds. The take estimates presented here do not take 
any of the mitigation measures presented earlier in this document into 
consideration. These take numbers also do not consider how many of the 
exposed animals may actually respond or react to the exploration 
drilling program. Instead, the take estimates are based on the presence 
of animals, regardless of whether or not they react or respond to the 
activities.

   Table 2--Population Abundance Estimates, Total Authorized Level B Take (When Combining Takes From Drillship
  Operations, Ice Management/Icebreaking, and ZVSP Surveys), and Percentage of Stock or Population That May Be
         Taken for the Potentially Affected Species That May Occur in Shell's Chukchi Sea Drilling Area
----------------------------------------------------------------------------------------------------------------
                                                                                      Total       Percentage of
                           Species                               Abundance \1\     authorized       stock or
                                                                                      take         population
----------------------------------------------------------------------------------------------------------------
Beluga Whale................................................          \2\ 3,710            15          0.04-0.4
                                                                     \3\ 39,258
Killer Whale................................................                656            15               2.3
Harbor Porpoise.............................................             48,215            15              0.03
Bowhead Whale...............................................         \4\ 15,232            53              0.35
Fin Whale...................................................              5,700            15              0.26
Gray Whale..................................................             18,017            46              0.26
Humpback Whale..............................................              2,845            15              0.53
Minke Whale.................................................          810-1,233            15         1.22-1.85
Bearded Seal................................................        \5\ 155,000            36              0.02
Ribbon Seal.................................................             49,000            15              0.03
Ringed Seal.................................................    208,000-252,000           814         0.32-0.39
Spotted Seal................................................             59,214            21              0.04
----------------------------------------------------------------------------------------------------------------
\1\ Unless stated otherwise, abundance estimates are taken from Allen and Angliss (2011).
\2\ Eastern Chukchi Sea stock population estimate.
\3\ Beaufort Sea stock population estimate.
\4\ Estimate from George et al. (2004) with an annual growth rate of 3.4%.
\5\ Beringia Distinct Population Segment (NMFS, 2010).


[[Page 27351]]

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 Chukchi Sea exploratory drilling program, and none are 
authorized. Injury, serious injury, or mortality could occur if there 
were a large or very large oil spill. However, as discussed previously 
in this document, the likelihood of a spill is extremely remote. Shell 
has implemented many design and operational standards to minimize the 
potential for an oil spill of any size. NMFS has not authorized take 
from an oil spill, as it is not part of the specified activity. 
Additionally, animals in the area are not expected to incur hearing 
impairment (i.e., TTS or PTS) or non-auditory physiological effects. 
Instead, any impact that could result from Shell's activities is most 
likely to be behavioral harassment and is expected to be of limited 
duration. Although it is possible that some individuals may be exposed 
to sounds from drilling operations more than once, during the migratory 
periods it is less likely that this will occur since animals will 
continue to move across the Chukchi Sea towards their wintering 
grounds.
    Bowhead and beluga whales are less likely to occur in the project 
area in July and August, as they are found mostly in the Canadian 
Beaufort Sea at this time. The animals are more likely to occur later 
in the season (mid-September through October), as they head west 
towards Russia or south towards the Bering Sea. Additionally, while 
bowhead whale tagging studies revealed that animals occurred in the LS 
193 area, a higher percentage of animals were found outside of the LS 
193 area in the fall (Quakenbush et al., 2010). Bowhead whales are not 
known to feed in areas near Shell's leases in the Chukchi Sea. The 
closest primary feeding ground is near Point Barrow, which is more than 
150 mi (241 km) east of Shell's Burger prospect, with additional 
evidence of feeding in recent years off Point Franklin close to shore 
(Clarke et al., 2011), which is more than 65 mi (105 km) from Shell's 
Burger prospect. There were no observations of feeding in the areas 
near Shell's proposed Burger prospect drill sites. Therefore, if 
bowhead whales stop to feed near Point Barrow on their fall westward 
migration (or off Point Franklin during the summer and fall months) 
during Shell's operations, the animals would not be exposed to 
continuous sounds from the drillship or icebreaker above 120 dB or to 
impulsive sounds from the airguns above 160 dB, as those sound levels 
only propagate 1.22 mi (1.97 km), 5.9 mi (9.5 km), and 3.42 mi (5.51 
km), respectively, which includes the inflation factor. Additionally, 
the 120-dB radius for the airgun array has been modeled to propagate 
6.5 mi (10.5 km) from the source (and would still be less than 10 mi 
[16.1 km] if an inflation factor of 1.5 were applied). Therefore, 
sounds from the operations would not reach the feeding grounds near 
Point Barrow or Point Franklin.
    Gray whales occur in the northeastern Chukchi Sea during the summer 
and early fall to feed. The COMIDA 2008-2010 Final Report (Clarke et 
al., 2011) notes 504 sightings of 835 gray whales during that time 
period, which were seen in every month of surveys each of the 3 years 
(i.e., June to November) between Wainwright and Barrow within 31 mi (50 
km) of shore. Clarke et al. (2011) note that sightings were also 
scattered throughout the study area more than 31 mi (50 km) offshore. 
The relative lack of gray whale sightings (and mud plumes, which are 
indicative of the presence of feeding gray whales) offshore was 
markedly different from that documented during surveys conducted from 
1982-1991, when gray whales were frequently seen on Hanna Shoal (Moore 
and Clarke, 1992 cited in Clarke et al., 2011). Gray whale sightings 
were most common in the survey blocks closer to shore in all months 
(Clarke et al., 2011). Based on this information, it appears that 
currently nearshore locations are being used more frequently than Hanna 
Shoal for feeding by gray whales. Both Hanna Shoals and the nearshore 
feeding grounds lie outside of the 120-dB and 160-dB ensonified areas 
from Shell's activities. While some individuals may swim through the 
area of active drilling, it is not anticipated to interfere with their 
feeding at Hanna Shoals or other Chukchi Sea feeding grounds. Other 
cetacean species (such as humpback and fin whales) are much rarer in 
the project area. The exposure of cetaceans to sounds produced by 
exploratory drilling operations (i.e., drillship, ice management/
icebreaking, and airgun operations) is not expected to result in more 
than Level B harassment.
    Few seals are expected to occur in the project area, as several of 
the species prefer more nearshore waters. Additionally, as stated 
previously in this document, pinnipeds appear to be more tolerant of 
anthropogenic sound, especially at lower received levels, than other 
marine mammals, such as mysticetes. Shell's activities would occur at a 
time of year when the ice seal species found in the region are not 
molting, breeding, or pupping. Therefore, these important life 
functions would not be impacted by Shell's activities.
    NMFS began receiving reports of an outbreak of skin lesions and 
sores for certain ice seal species in summer 2011 and declared an 
unusual mortality event in December 2011. An investigative team was 
established, and testing has been underway. As noted in the response to 
Comment 34 earlier in this document, testing has ruled out numerous 
bacteria and viruses known to affect marine mammals. Reports from the 
NSB indicate that hunters during early winter observed many healthy 
bearded and ringed seals. The seals behaved normally: they were 
playful, curious but cautious, and maintained distance from boats. No 
lesions were observed on any seals. Chukotka hunters did not report any 
sightings or harvest of sick and/or hairless seals in December 2011 and 
January 2012. The data available to date do not indicate that this 
outbreak has weakened the population. Moreover, Shell's activities are 
anticipated to take less than 1% of the population of all of the stocks 
of all three species observed to have the sores and lesions (i.e., 
ringed, bearded, and spotted seals). The sound that will be produced by 
Shell's activities is of a low level. Therefore, even if the population 
were weakened from this outbreak it would not change our evaluation of 
the impacts of this activity at the population level. The exposure of 
pinnipeds to sounds produced by Shell's exploratory drilling operations 
in the Chukchi Sea is not expected to result in more than Level B 
harassment of the affected species or stock.
    Of the 12 marine mammal species likely to occur in the drilling 
area, three are listed as endangered under the ESA: The bowhead, 
humpback, and fin whales. All three species are also designated as 
``depleted'' under the MMPA. Despite these designations, the Bering-
Chukchi-Beaufort stock of bowheads has been increasing at a rate

[[Page 27352]]

of 3.4% annually for nearly a decade (Allen and Angliss, 2011), even in 
the face of ongoing industrial activity. 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, 2011). An annual increase of 
4.8% was estimated for the period 1987-2003 for North Pacific fin 
whales. While this estimate is consistent with growth estimates for 
other large whale populations, it should be used with caution due to 
uncertainties in the initial population estimate and about population 
stock structure in the area (Allen and Angliss, 2011). Zeribini et al. 
(2006, cited in Allen and Angliss, 2011) noted an increase of 6.6% for 
the Central North Pacific stock of humpback whales in Alaska waters. 
Certain stocks or populations of gray and beluga whales and spotted 
seals are listed as endangered or are proposed for listing under the 
ESA; however, none of those stocks or populations occur in the activity 
area. On December 10, 2010, NMFS published a notice of proposed 
threatened status for subspecies of the ringed seal (75 FR 77476) and a 
notice of proposed threatened and not warranted status for subspecies 
and distinct population segments of the bearded seal (75 FR 77496) in 
the Federal Register. Neither of these two ice seal species is 
currently considered depleted under the MMPA. The ribbon seal is a 
``species of concern.'' None of the other species that may occur in the 
project area are listed as threatened or endangered under the ESA or 
designated as depleted under the MMPA. There is currently no 
established critical habitat in the project area for any of these 12 
species.
    Potential impacts to marine mammal habitat were discussed in detail 
in the Notice of Proposed IHA (76 FR 69958, November 9, 2011; see the 
``Anticipated Effects on Habitat'' section). Although some disturbance 
is possible to food sources of marine mammals, any impacts to affected 
marine mammal stocks or species are anticipated to be minor. Based on 
the vast size of the Arctic Ocean where feeding by marine mammals 
occurs versus the localized area of the drilling program, any missed 
feeding opportunities in the direct project area would be of little 
consequence, as marine mammals would have access to other feeding 
grounds.
    The estimated takes authorized represent less than 1% of the 
affected population or stock for 10 of the species and less than 2.5% 
for two of the species. 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.
    The estimated take numbers are likely an overestimate for several 
reasons. First, these take numbers were calculated using a 50% 
inflation factor of the 120-dB radius from the drillship and of the 
160-dB radius for the airguns and using a 25% inflation factor of the 
120-dB radius from the icebreaker during active ice management/
icebreaking activities, which is a precautionary approach recommended 
by some acousticians when modeling a new sound source in a new location 
and because the radii were based on results from measurements of the 
Discoverer in another location and of the icebreaker and airguns in the 
Arctic Ocean. SSV tests may reveal that the Level B harassment zone is 
either smaller or larger than that used to estimate take. If the SSV 
tests reveal that the Level B harassment zone is slightly larger than 
those modeled or measured elsewhere, the inflation factors should cover 
the discrepancy, however, based on recent SSV tests of seismic airguns 
(which showed that the measured 160-dB isopleth was in the area of the 
modeled value), the 50% correction factor likely results in an 
overestimate of takes. Moreover, the mitigation and monitoring measures 
(described previously in this document) included in the IHA are 
expected to reduce even further any potential disturbance to marine 
mammals. Last, some marine mammal individuals, including mysticetes, 
have been shown to avoid the ensonified area around airguns at certain 
distances (Richardson et al., 1999), and, therefore, some individuals 
would not likely enter into the Level B harassment zones for the 
various types of activities. Based on the best available information, 
the mitigation and monitoring protocols that will be implemented by 
Shell, and the extremely low likelihood of a major oil spill occurring, 
NMFS has determined that the take, by Level B harassment, from Shell's 
activities would have no more than a negligible impact on the affected 
marine mammal species and stocks.

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

Relevant Subsistence Uses

    The disturbance and potential displacement of marine mammals by 
sounds from drilling activities are the principal concerns related to 
subsistence use of the area. Subsistence remains the basis for Alaska 
Native culture and community. Marine mammals are legally hunted in 
Alaskan waters by coastal Alaska Natives. In rural Alaska, subsistence 
activities are often central to many aspects of human existence, 
including patterns of family life, artistic expression, and community 
religious and celebratory activities. Additionally, the animals taken 
for subsistence provide a significant portion of the food that will 
last the community throughout the year. The main species that are 
hunted include bowhead and beluga whales, ringed, spotted, and bearded 
seals, walruses, and polar bears. (As mentioned previously in this 
document, both the walrus and the polar bear are under the USFWS' 
jurisdiction.) The importance of each of these species varies among the 
communities and is largely based on availability.
    The subsistence communities in the Chukchi Sea that have the 
potential to be impacted by Shell's offshore drilling program include 
Point Hope, Point Lay, Wainwright, Barrow, and possibly Kotzebue and 
Kivalina (however, these two communities are much farther to the south 
of the proposed project area). Wainwright is the coastal village 
closest to the proposed drill site and is located approximately 78 mi 
(125.5 km) from Shell's Burger prospect. Point Lay, Barrow, and Point 
Hope are all approximately 92, 140, and 206 mi (148, 225.3, and 332 
km), respectively, from Shell's Burger prospect.
(1) Bowhead Whales
    Bowhead whale hunting is a key activity in the subsistence 
economies of northwest Arctic communities. The whale harvests have a 
great influence on social relations by strengthening the sense of 
Inupiat culture and heritage in addition to reinforcing family and 
community ties.
    An overall quota system for the hunting of bowhead whales was 
established by the International Whaling Commission (IWC) in 1977. The 
quota is now regulated through an agreement between NMFS and the AEWC. 
The AEWC allots the number of bowhead whales that each whaling 
community may harvest annually (USDOI/BLM, 2005). The annual take of 
bowhead whales has varied due to (a) changes in the allowable quota 
level and (b) year-to-year variability in ice and weather conditions, 
which strongly influence the success of the hunt.
    Bowhead whales migrate around northern Alaska twice each year, 
during the spring and autumn, and are hunted in both seasons. Bowhead 
whales are hunted from Barrow during the spring

[[Page 27353]]

and the fall migration. The spring hunt along Chukchi villages and at 
Barrow occurs after leads open due to the deterioration of pack ice; 
the spring hunt typically occurs from early April until the first week 
of June. From 1984-2009, bowhead harvests by the villages of 
Wainwright, Point Hope, and Point Lay occurred only between April 14 
and June 24 and only between April 23 and June 15 in Barrow (George and 
Tarpley, 1986; George et al., 1987, 1988, 1990, 1992, 1995, 1998, 1999, 
2000; Philo et al., 1994; Suydam et al., 1995b, 1996, 1997, 2001b, 
2002, 2003, 2004, 2005b, 2006, 2007, 2008, 2009, 2010). Shell will not 
mobilize and move into the Chukchi Sea prior to July 1.
    The fall migration of bowhead whales that summer in the eastern 
Beaufort Sea typically begins in late August or September. Fall 
migration into Alaskan waters is primarily during September and 
October. In the fall, subsistence hunters use aluminum or fiberglass 
boats with outboards. Hunters prefer to take bowheads close to shore to 
avoid a long tow during which the meat can spoil, but Braund and 
Moorehead (1995) report that crews may (rarely) pursue whales as far as 
50 mi (80 km). The autumn bowhead hunt usually begins in Barrow in mid-
September and mainly occurs in the waters east and northeast of Point 
Barrow. Fall bowhead whaling has not typically occurred in the villages 
of Wainwright, Point Hope, and Point Lay. However, Wainwright whaling 
crews harvested one bowhead whale on October 7, 2010, and one bowhead 
whale on October 28, 2011. Because of changing ice conditions, there is 
the potential for these villages to resume a fall bowhead harvest. 
Additionally, residents of Point Lay have not hunted bowhead whales in 
the recent past but were selected by the IWC to receive a bowhead whale 
quota in 2009, and began bowhead hunting again in 2009 and harvested a 
bowhead on May 5, 2009, during the spring hunt. In the more distant 
past, Point Lay hunters traveled to Barrow, Wainwright, or Point Hope 
to participate in the bowhead whale harvest activities.
    Barrow participates in a fall hunt each year. From 1984-2009, 
Barrow whalers harvested bowhead whales between August 31 and October 
29. While this time period overlaps with that of Shell's proposed 
operations, the drill sites are located more than 140 mi (225 km) west 
of Barrow, so the whales would reach the Barrow hunting grounds before 
entering the sound field of Shell's operations. Shell will be flying 
helicopters out to the drillship for resupply missions. However, Shell 
will communicate with the communities about helicopter routes and has 
agreed to conditions in the signed 2012 CAA to avoid conflicts with 
helicopter flights. In the past 35 years, however, Barrow whaling crews 
have harvested almost all whales in the Beaufort Sea to the east of 
Point Barrow (Suydam et al., 2008), indicating that relatively little 
fall hunting occurs to the west where the flight corridor is located.
(2) Beluga Whales
    Beluga whales are available to subsistence hunters along the coast 
of Alaska in the spring when pack-ice conditions deteriorate and leads 
open up. Belugas may remain in coastal areas or lagoons through June 
and sometimes into July and August. The community of Point Lay is 
heavily dependent on the hunting of belugas in Kasegaluk Lagoon for 
subsistence meat. From 1983-1992 the average annual harvest was 
approximately 40 whales (Fuller and George, 1997). Point Hope residents 
hunt beluga primarily in the lead system during the spring (late March 
to early June) bowhead hunt but also in open-water along the coastline 
in July and August. Belugas are harvested in coastal waters near these 
villages, generally within a few miles from shore.
    In Wainwright and Barrow, hunters usually wait until after the 
spring bowhead whale hunt is finished before turning their attention to 
hunting belugas. The average annual harvest of beluga whales taken by 
Barrow for 1962-1982 was five (MMS, 1996). The Alaska Beluga Whale 
Committee (ABWC) recorded that 23 beluga whales had been harvested by 
Barrow hunters from 1987 to 2002, ranging from 0 in 1987, 1988 and 1995 
to the high of 8 in 1997 (Fuller and George, 1997; ABWC, 2002 cited in 
USDOI/BLM, 2005). Barrow residents typically hunt for belugas between 
Point Barrow and Skull Cliffs in the Chukchi Sea (primarily April-June) 
and later in the summer (July-August) on both sides of the barrier 
island in Elson Lagoon/Beaufort Sea (MMS, 2008). Harvest rates indicate 
that the hunts are not frequent. Wainwright residents hunt beluga in 
April-June in the spring lead system, but this hunt typically occurs 
only if there are no bowheads in the area. Communal hunts for beluga 
are conducted along the coastal lagoon system later in July-August. 
Shell's exploration drilling activities take place well offshore, far 
away from areas that are used for beluga hunting by the Chukchi Sea 
communities.
(3) Ringed Seals
    Ringed seals are hunted mainly from October through June. Hunting 
for these smaller mammals is concentrated during winter (November 
through March) because bowhead whales, bearded seals, and caribou are 
available through other seasons. In winter, leads and cracks in the ice 
off points of land and along the barrier islands are used for hunting 
ringed seals. The average annual ringed seal harvest was 49 seals in 
Point Lay, 86 in Wainwright, and 394 in Barrow (Braund et al., 1993; 
USDOI/BLM, 2003, 2005). Although ringed seals are available year-round, 
the planned activities will not occur during the primary period when 
these seals are typically harvested (November-March). Also, the 
activities will be largely in offshore waters where they will not 
influence ringed seals in the nearshore areas where they are hunted.
(4) Spotted Seals
    The spotted seal subsistence hunt peaks in July and August along 
the shore where the seals haul out, but usually involves relatively few 
animals. Available maps of recent and past subsistence use areas for 
spotted seals indicate harvest of this species within 30-40 mi (48-64 
km) of the coastline. Spotted seals typically migrate south by October 
to overwinter in the Bering Sea. During the fall migration, spotted 
seals are hunted by the Wainwright and Point Lay communities as the 
seals move south along the coast (USDOI/BLM, 2003). Spotted seals are 
also occasionally hunted in the area off Point Barrow and along the 
barrier islands of Elson Lagoon to the east (USDOI/BLM, 2005). The 
planned activities will remain offshore of the coastal harvest area of 
these seals and should not conflict with harvest activities.
(5) Bearded Seals
    Bearded seals, although generally not favored for their meat, are 
important to subsistence activities in Barrow and Wainwright because of 
their skins. Six to nine bearded seal hides are used by whalers to 
cover each of the skin-covered boats traditionally used for spring 
whaling. Because of their valuable hides and large size, bearded seals 
are specifically sought. Bearded seals are harvested during the spring 
and summer months in the Chukchi Sea (USDOI/BLM, 2003, 2005). The 
animals inhabit the environment around the ice floes in the drifting 
nearshore ice pack, so hunting usually occurs from boats in the drift 
ice. Most bearded seals are harvested in coastal areas inshore of the 
proposed exploration drilling area, so no conflicts with the harvest of 
bearded seals are expected.

[[Page 27354]]

Potential Impacts to Subsistence Uses

    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 
as an impact resulting from the specified activity that is likely to 
reduce the availability of the species to a level insufficient for a 
harvest to meet subsistence needs by causing the marine mammals to 
abandon or avoid hunting areas; directly displacing subsistence users; 
or placing physical barriers between the marine mammals and the 
subsistence hunters; and 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 drilling program have the 
potential to impact marine mammals hunted by Native Alaskans. In the 
case of cetaceans, the most common reaction to anthropogenic sounds (as 
noted previously) 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. Helicopter activity also 
has the potential to disturb cetaceans and pinnipeds by causing them to 
vacate the area. Additionally, general vessel presence in the vicinity 
of traditional hunting areas could negatively impact a hunt. Native 
knowledge indicates that bowhead whales become increasingly 
``skittish'' in the presence of seismic noise. Whales are more wary 
around the hunters and tend to expose a much smaller portion of their 
back when surfacing (which makes harvesting more difficult). 
Additionally, natives report that bowheads exhibit angry behaviors in 
the presence of seismic activity, such as tail-slapping, which 
translate to danger for nearby subsistence harvesters.
    In the unlikely event of an oil spill, marine mammals could become 
contaminated and therefore unavailable to subsistence users. 
Additionally, perception could also affect availability of marine 
mammals for subsistence uses. Even if whales or seals are not oiled or 
contaminated by an oil spill, the mere perception that they could be 
contaminated could reduce the availability of marine mammals for 
subsistence uses.

Plan of Cooperation (POC)

    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 developed a POC for its 2012 
Chukchi Sea, Alaska, exploration drilling program to minimize any 
adverse impacts on the availability of marine mammals for subsistence 
uses. A copy of the Draft POC was provided to NMFS with the IHA 
Application as Attachment D (see ADDRESSES for availability). Meetings 
with potentially affected subsistence users began in 2009 and continued 
into 2010 and 2011 (see Table 4.2-1 in Shell's POC for a list of all 
meetings conducted through April 2011). During these meetings, Shell 
focused on lessons learned from prior years' activities and presented 
mitigation measures for avoiding potential conflicts, which are 
outlined in the 2012 POC and this document. Shell's POC addresses 
vessel transit, drilling, and associated activities. Communities that 
were consulted regarding Shell's 2012 Arctic Ocean operations include: 
Barrow, Kaktovik, Wainwright, Kotzebue, Kivalina, Point Lay, Point 
Hope, Kiana, Gambell, Savoonga, and Shishmaref.
    Beginning in early January 2009 and continuing into 2011, Shell 
held one-on-one meetings with representatives from the NSB and 
Northwest Arctic Borough (NWAB), subsistence-user group leadership, and 
Village Whaling Captain Association representatives. Shell's primary 
purpose in holding individual meetings was to inform and prepare key 
leaders, prior to the public meetings, so that they would be prepared 
to give appropriate feedback on planned activities.
    Shell presented the proposed project to the NWAB Assembly on 
January 27, 2009, to the NSB Assembly on February 2, 2009, and to the 
NSB and NWAB Planning Commissions in a joint meeting on March 25, 2009. 
Meetings were also scheduled with representatives from the AEWC, and 
presentations on proposed activities were given to the Inupiat 
Community of the Arctic Slope, and the Native Village of Barrow. On 
December 8, 2009, Shell held consultation meetings with representatives 
from the various marine mammal commissions. Prior to drilling in 2012, 
Shell will also hold additional consultation meetings with the affected 
communities and subsistence user groups, NSB, and NWAB to discuss the 
mitigation measures included in the POC. Shell presented information 
regarding the proposed operations and marine mammal monitoring plans at 
the 2012 Arctic Open Water Meeting in Anchorage, Alaska, which was held 
March 6-8, 2012. Shell also attended the 2011 CAA negotiation meetings 
in support of a limited program of marine environmental baseline 
activities in 2011 taking place in the Beaufort and Chukchi seas. Shell 
has stated that it is committed to a CAA process and will demonstrate 
this by making a good-faith effort to negotiate a CAA every year it has 
planned activities. To that end, Shell attended the 2012 CAA 
negotiation meetings and signed the 2012 CAA on March 26, 2012.
    The following mitigation measures, plans and programs, are integral 
to the POC and were developed during consultation with potentially 
affected subsistence groups and communities. These measures, plans, and 
programs will be implemented by Shell during its 2012 exploration 
drilling operations in both the Beaufort and Chukchi Seas to monitor 
and mitigate potential impacts to subsistence users and resources. The 
mitigation measures Shell has adopted and will implement during its 
2012 Chukchi Sea offshore exploration drilling operations are listed 
and discussed below. This most recent version of Shell's planned 
mitigation measures was presented to community leaders and subsistence 
user groups starting in January of 2009 and has evolved since in 
response to information learned during the consultation process.
    To minimize any cultural or resource impacts to subsistence 
activities from its exploration operations, Shell 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 the subsistence hunts for marine 
mammals:
    (1) The drillship and support vessels will not enter the Chukchi 
Sea before July 1;
    (2) To minimize impacts on marine mammals and subsistence hunting 
activities, vessels that can safely travel outside of the polynya zone 
will do so. In the event the transit outside of the polynya zone 
results in Shell having to break ice (as opposed to managing ice by 
pushing it out of the way), the drillship and support vessels will 
enter into the polynya zone far enough so that ice breaking is not 
necessary. 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 Communication Centers (Com Centers);
    (3) Shell has developed a Communication Plan and will implement the 
plan before initiating exploration drilling operations 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

[[Page 27355]]

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 and 
Call Centers to be located in coastal villages along the Chukchi and 
Beaufort Seas during Shell's proposed activities in 2012;
    (4) 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 will be a total of nine 
subsistence advisor-liaison positions (one per village), to work 
approximately 8 hours per day and 40-hour weeks through Shell's 2012 
exploration project. The subsistence advisor will use local knowledge 
(Traditional Knowledge) to gather data on subsistence lifestyle within 
the community and advise on ways to minimize and mitigate potential 
impacts to subsistence resources during the drilling season. 
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;
    (5) Shell will recycle drilling muds (e.g., use those muds on 
multiple wells), to the extent practicable based on operational 
considerations (e.g., whether mud properties have deteriorated to the 
point where they cannot be used further), to reduce discharges from its 
operations. At the end of the season excess water base fluid will be 
pre-diluted to a 30:1 ratio with seawater and then discharged;
    (6) Shell will implement flight restrictions prohibiting aircraft 
from flying within 1,000 ft (305 m) of marine mammals or below 1,500 ft 
(457 m) altitude (except during marine mammal monitoring, takeoffs and 
landings, or in emergency situations) while over land or sea;
    (7) Vessels within 900 ft (274 m) of marine mammals will reduce 
speed, avoid separating members from a group, and avoid multiple 
changes in direction;
    (8) Vessels underway will alter course to avoid impacts to marine 
mammals, including collisions;
    (9) The drilling support fleet will avoid known fragile ecosystems, 
including the Ledyard Bay Critical Habitat Unit and will include 
coordination through the Com Centers; and
    (10) Vessel speeds will be reduced during inclement weather 
conditions in order to reduce the potential for collisions with marine 
mammals.
    Aircraft and vessel traffic between the drill sites and support 
facilities in Wainwright, and aircraft traffic between the drill sites 
and air support facilities in Barrow would traverse areas that are 
sometimes used for subsistence hunting of belugas. Disturbance 
associated with vessel and aircraft traffic could therefore potentially 
affect beluga hunts. Vessel and aircraft traffic associated with 
Shell's proposed drilling program will be restricted under normal 
conditions to designated corridors that remain onshore or proceed 
directly offshore thereby minimizing the amount of traffic in coastal 
waters where beluga hunts take place. The designated traffic corridors 
do not traverse areas indicated in recent mapping as utilized by 
Barrow, Point Lay, or Point Hope for beluga hunts. The corridor avoids 
important beluga hunting areas in Kasegaluk Lagoon.
    The POC also contains measures regarding ice management procedures, 
critical operations procedures, the blowout prevention program, and oil 
spill response. Some of the oil spill response measures to reduce 
impacts to subsistence hunts include: having the primary OSRV on 
standby at all times so that it is available within 1 hour if needed; 
the remainder of the OSR fleet will be available within 72 hours if 
needed and will be capable of collecting oil on the water up to the 
calculated Worst Case Discharge; oil spill containment equipment will 
be available in the unlikely event of a blowout; capping stack 
equipment will be stored aboard one of the ice management vessels and 
will be available for immediate deployment in the unlikely event of a 
blowout; and pre-booming will be required for all fuel transfers 
between vessels.

Unmitigable Adverse Impact Analysis and Determination

    Shell has adopted a spatial and temporal strategy for its Chukchi 
Sea operations that should minimize impacts to subsistence hunters. 
Shell will enter the Chukchi Sea far offshore, so as to not interfere 
with July hunts in the Chukchi Sea villages and will communicate with 
the Com Centers to notify local communities of any changes in the 
transit route. After the close of the July beluga whale hunts in the 
Chukchi Sea villages, very little whaling occurs in Wainwright, Point 
Hope, and Point Lay. Although the fall bowhead whale hunt in Barrow 
will occur while Shell is still operating (mid- to late September to 
October), Barrow is located 140 mi (225 km) east of the proposed drill 
sites. Based on these factors, Shell's Chukchi Sea operations are not 
expected to interfere with the fall bowhead harvest in Barrow. In 
recent years, bowhead whales have occasionally been taken in the fall 
by coastal villages along the Chukchi coast, but the total number of 
these animals has been small. Wainwright landed its first fall whale in 
more than 90 years in October 2010 and landed a second whale in October 
2011. Hunters from the northwest Arctic villages prefer to harvest 
whales within 50 mi (80 km) so as to avoid long tows back to shore.
    Adverse impacts are not anticipated on sealing activities since the 
majority of hunts for seals occur in the winter and spring, when Shell 
will not be operating. Additionally, most sealing activities occur much 
closer to shore than Shell's proposed drill sites.
    Shell will also support the village Com Centers in the Arctic 
communities and employ local Subsistence Advisors from the Beaufort and 
Chukchi Sea villages to provide consultation and guidance regarding the 
whale migration and subsistence hunt. The Subsistence Advisors will 
provide advice to Shell on ways to minimize and mitigate potential 
impacts to subsistence resources during the drilling season. Support 
activities, such as helicopter flights, could impact nearshore 
subsistence hunts. However, Shell will use flight paths and agreed upon 
flight altitudes to avoid adverse impacts to hunts and will communicate 
regularly with the Com Centers.
    In the unlikely event of a major oil spill in the Chukchi Sea, 
there could be major impacts on the availability of marine mammals for 
subsistence uses (such as displacement from traditional hunting grounds 
and contaminated animals taken for harvests). As discussed earlier in 
this document, the probability of a major oil spill occurring over the 
life of the project is low (Bercha, 2008). As a condition of the 2012 
CAA that Shell signed on March 26, 2012, any company engaged in 
drilling operations agrees to enter into a binding oil spill mitigation 
agreement with the AEWC, NSB, and ICAS to provide for hunter transport 
to alternate hunting locations in the unlikely event of an oil spill. 
Additionally, Shell developed an OSRP, which was recently approved by 
BSEE after review and comment by DOI and several Federal agencies and 
the public. Shell has also incorporated several mitigation measures 
into its operational design to reduce further the risk of an oil spill. 
Based on the information available, the mitigation measures that Shell 
will

[[Page 27356]]

implement, and the extremely low likelihood of a major oil spill 
occurring, NMFS has determined that Shell's activities will not have an 
unmitigable adverse impact on the availability of marine mammals for 
subsistence uses.

Endangered Species Act (ESA)

    There are three marine mammal species listed as endangered under 
the ESA with confirmed or possible occurrence in the proposed project 
area: the bowhead, humpback, and fin whales. There are two marine 
mammal species proposed for listing as threatened with confirmed or 
possible occurrence in the project area: ringed and bearded seals. 
NMFS' Permits and Conservation Division conducted consultation with 
NMFS' Endangered Species Division under section 7 of the ESA on the 
issuance of an IHA to Shell under section 101(a)(5)(D) of the MMPA for 
this activity. In April, 2012, NMFS finished conducting its section 7 
consultation and issued a Biological Opinion, and concluded that the 
issuance of the IHA associated with Shell's 2012 Chukchi Sea drilling 
program is not likely to jeopardize the continued existence of the 
endangered bowhead, humpback, and fin whale, the Arctic sub-species of 
ringed seal, or the Beringia distinct population segment of bearded 
seal. No critical habitat has been designated for these species, 
therefore none will be affected.

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 an exploratory drilling 
program in the Chukchi Sea, Alaska. NMFS has finalized the EA and 
prepared a FONSI for this action. Therefore, preparation of an 
Environmental Impact Statement is not necessary. NMFS' EA was available 
to the public for a 30-day comment period before it was finalized.

Authorization

    As a result of these determinations, NMFS has issued an IHA to 
Shell for the take of marine mammals, by Level B harassment, incidental 
to conducting an offshore exploratory drilling program in the Chukchi 
Sea during the 2012 open-water season, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated.

    Dated: May 2, 2012.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-11094 Filed 5-8-12; 8:45 am]
BILLING CODE 3510-22-P