Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to an Exploration Drilling Program in the Chukchi Sea, Alaska, 35743-35780 [2015-15013]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 119 (Monday, June 22, 2015)]
[Notices]
[Pages 35743-35780]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-15013]



[[Page 35743]]

Vol. 80

Monday,

No. 119

June 22, 2015

Part II





Department of Commerce





-----------------------------------------------------------------------





National Oceanic and Atmospheric Administration





-----------------------------------------------------------------------





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. 80, No. 119 / Monday, June 22, 2015 / 
Notices

[[Page 35744]]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD655


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.

-----------------------------------------------------------------------

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, 2015, through October 31, 2015.

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 Jolie 
Harrison, 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: Shane Guan, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    An 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''.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On September 18, 2014, Shell submitted an application to NMFS for 
the taking of marine mammals incidental to exploration drilling 
activities in the Chukchi Sea, Alaska. After receiving comments and 
questions from NMFS, Shell revised its IHA application and related 
Marine Mammal Mitigation and Monitoring Plan (4MP) on December 17, 
2014. NMFS determined that the application was adequate and complete on 
January 5, 2015.
    NMFS published a Notice of Proposed IHA in the Federal Register on 
March 4, 2015 (80 FR 11726). That notice contained in-depth 
descriptions and analyses that may be summarized but are generally not 
repeated in this document. Only in cases where descriptions or analyses 
changed is that information updated here.
    The proposed activity would occur between July and October 2015. 
The following specific aspects of the proposed activities are likely to 
result in the take of marine mammals: Exploration drilling, supply and 
drilling support vessels using dynamic positioning, mudline cellar 
construction, anchor handling, ice management activities, and zero-
offset vertical seismic profiling (ZVSP) activities.
    Shell requested an 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 proposed to 
authorize take of 12 marine mammal species, by Level B harassment, 
incidental to Shell's offshore exploration drilling in the Chukchi Sea. 
These species are: 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).
    In 2012, NMFS issued two IHAs to Shell to conduct two exploratory 
drilling activities at exploration wells in the Beaufort (77 FR 27284; 
May 9, 2012) and Chukchi (77 FR 27322; May 9, 2012) Seas, Alaska, 
during the 2012 Arctic open-water season (July through October). 
Shell's proposed 2015 exploration drilling program is similar though 
not identical to those conducted in 2012. (In December 2012, Shell 
submitted two additional IHA applications to take marine mammals 
incidental to its proposed exploratory drilling in Beaufort and Chukchi 
Seas during the 2013 open-water season. However, Shell withdrew its 
application in February 2013).

Description of the Specified Activity

Overview

    Shell proposes to conduct exploration drilling at up to four 
exploration drill sites at Shell's Burger Prospect on the OCS leases 
acquired from the U.S. Department of the Interior, Bureau of Ocean 
Energy Management (BOEM). The exploration drilling planned for the 2015 
season is a continuation of the Chukchi Sea exploration drilling 
program that began in 2012, and resulted in the completion of a partial 
well at the location known as Burger A.
    Shell plans to use two drilling units, the drillship Noble 
Discoverer (Discoverer) and semi-submersible Transocean Polar Pioneer 
(Polar Pioneer) to drill at up to four locations on the Burger 
Prospect. Both drilling units will be attended to by support vessels 
for the purposes of ice management, anchor handling, oil spill response 
(OSR), refueling, support to drilling units, and resupply. The

[[Page 35745]]

drilling units will be accompanied by a greater number of support 
vessels, aircraft, and oil spill response vessels (OSRV) greater than 
the number deployed during the 2012 drilling season.

Dates and Duration

    Shell anticipates that its exploration drilling program will occur 
between July 1 and approximately October 31, 2015. The drilling units 
will move through the Bering Strait and into the Chukchi Sea on or 
after July 1, 2015, and then onto the Burger Prospect as soon as ice 
and weather conditions allow. Exploration drilling activities will 
continue until about October 31, 2015, and the drilling units and 
support vessels will exit the Chukchi Sea at the conclusion of the 
exploration drilling season.

Specified Geographic Region

    All drill sites at which exploration drilling would occur in 2015 
will be at Shell's Burger Prospect (see Figure 1-1 on page 1-2 of 
Shell's IHA application). Shell has identified a total of six Chukchi 
Sea lease blocks on the Burger Prospect. All six drill sites are 
located more than 64 mi (103 km) off the Chukchi Sea coast. During 
2015, the Discoverer and Polar Pioneer will be used to conduct 
exploration drilling activities at up to four of the six exploration 
drill sites (up to two at a time). As with any Arctic exploration 
program, weather and ice conditions will dictate actual operations.

Detailed Description of Activities

    The Notice of Proposed IHA (80 FR 11726; March 4, 2015) 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. There is no change to Shell's planned exploration 
drilling activity, therefore, the information is not repeated here. 
Please refer to the proposed IHA notice for the full description of the 
specified activity.

Comments and Responses

    A Notice of Proposed IHA published in the Federal Register on March 
4, 2015 (80 FR 11726) for public comment. During the 30-day public 
comment period, NMFS received 8 comment letters from the following: The 
Marine Mammal Commission (Commission); the Alaska Eskimo Whaling 
Commission (AEWC); the North Slope Borough (NSB); Shell; the Northern 
Alaska Environment Center (NAEC); the Environmental Investigation 
Agency (EIA); Oceana, Ocean Conservancy, and Audubon Alaska 
(collectively Oceana); and Alaska Wilderness League (AWL), Center for 
Biological Diversity, Earthjustice, EIA, Greenpeace, Natural Resources 
Defense Council, NAEC, Ocean Conservation Research, and Sierra Club 
(collectively ``AWL''), along with a form letter signed by 180,036 
private citizens (with many duplicate submissions).
    All of the public comment letters received on the Notice of 
Proposed IHA (80 FR 11726; March 4, 2015) 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: The Commission notes that NMFS does not typically 
authorize the taking of marine mammals incidental to mudline 
construction and anchor handling. The Commission further recommends 
that if NMFS intends to authorize the taking of marine mammals 
incidental to these types of activities, NMFS should provide guidance 
and follow a consistent approach in assessing the potential for taking 
by Level B harassment, including whether applicants should include 
requests for authorizations of such taking in their applications.
    Response: NMFS has not authorized marine mammal takes by Level B 
harassment that result from mudline cellar construction and anchor 
handling because there had been no documentation that noises generated 
from such activities were significant enough to cause take. The noise 
levels of these activities were first measured during the sound source 
verification tests for Shell's exploration drilling activities in the 
Beaufort and Chukchi seas in 2012, and were reported in the 90-day 
reports of these activities. As detailed in the notice for the proposed 
IHA (80 FR 11726; March 4, 2015), the Level B harassment radii (120-dB 
isopleths) for mudline cellar construction and anchor handling are 8.2 
and 19 km from the sources, respectively.
    For determining whether impacts from sound-generating activities 
rise to Level B harassment of marine mammals, NMFS' current guidance is 
that if an animal is exposed to received noise levels higher than 160-
dB for impulse source or 120-dB for non-impulse source, then it is 
considered a take. In the case of mudline cellar construction and 
anchor handling, NMFS required sound source verification (SSV) tests on 
these sources in the 2012 IHAs issued to Shell for its 2012 open-water 
exploration drilling activities. The results showed that these 
activities generate significant underwater noise that could result in 
take under NMFS' current guidance for marine mammal behavioral 
harassment, and NMFS considers that takes are likely from these 
activities for Shell's 2015 exploration drilling activity in the 
Chukchi Sea. As a result, impacts from these sound sources should be 
considered in future incidental take applications and analyses.
    Comment 2: The NSB requests an extension of the 30-day comment 
period for the proposed IHA. The NSB states that because Shell's 
Chukchi Sea Exploration Plan is incredibly detailed, yet has not yet 
been ``deemed submitted'' by the Bureau of Ocean Energy Management 
(BOEM), the NSB has not had the opportunity to review all the details. 
In addition, the NSB states that having two drill rigs operating near 
one another could cause major impacts, and that without evaluating the 
entire Exploration Plan, the NSB cannot fully evaluate how all aspects 
of the operation will move forward, nor can the NSB evaluate the 
cumulative impacts on marine mammals.
    Response: NMFS received the NSB's request on April 3, 2015, the 
last day of the comment period for the proposed IHA. As a practical 
matter an extension of the public comment period would not have been 
possible given the short time period left to consider the request. 
Section 101(a)(5)(D) of the MMPA was intended to provide a mechanism 
for more expedited review and issuance of marine mammal incidental take 
authorizations (than section 101(a)(5)(A)), assuming the required 
findings can be made. We complied with the 30-day public comment period 
specified in the statute. In this case, an extension of or an 
additional comment period could have delayed issuance of the IHA in the 
timeframe requested by Shell for it to conduct its specified activity.
    Although Shell's Exploration Plan was not ``deemed submitted'' by 
BOEM until after the closing of NMFS' public comment period, we note 
that a second draft ``Revision 2'' of Shell's Chukchi Sea Exploration 
Plan was submitted to BOEM and publicly available since August 2014. 
See https://www.boem.gov/shell-chukchi/. Further, the information 
provided to NMFS in Shell's IHA application and marine mammal 
mitigation and monitoring plan (4MP) contained substantial information 
for NMFS to analyze potential impacts to marine mammals from Shell's 
proposed

[[Page 35746]]

exploration drilling. Information provided by Shell to NMFS for impact 
analysis included a detailed description of the acoustic footprint from 
two drill rigs operating near one another, and total ensonified area 
resulting from two different sources. Therefore, adequate information 
was publicly available to evaluate potential impacts to marine mammals 
from Shell's proposed exploration drilling activities in the Chukchi 
during the 2015 Arctic open-water season even before the Exploration 
Plan was officially deemed submitted.
    Comment 3: The NSB noted that NMFS convened an independent peer 
review panel to review Shell's 4MP for the proposed exploration 
drilling in the Chukchi Sea, and that after the review process NMFS 
will consider all recommendations made by the panel and incorporate 
appropriate changes in the monitoring requirements of the IHA (if 
issued). The NSB states that it would be useful to the NSB to have the 
benefit of this feedback and proposed changes when evaluating the IHA.
    Response: In evaluating potential marine mammal impacts from 
Shell's proposed exploration drilling program in the Chukchi Sea, NMFS 
published a Federal Register notice of proposed IHA for public comment. 
The Federal Register notice contains substantial information on Shell's 
proposed activities, potential impacts to marine mammals and 
subsistence harvest, and proposed mitigation, monitoring, and reporting 
measures. In addition, Shell's IHA application and 4MP are posted on 
NMFS' Web site along with the Federal Register for public examination 
and comments. Furthermore, the peer-review panel report on Shell's 4MP, 
along with the panel's recommendations, as well as changes made by NMFS 
to the monitoring and reporting measures, are available to the public 
in this document and will be posted on NMFS' Web site. However, due to 
the short duration of the statutory timeframe of the IHA process (120 
days), it was not possible to afford additional time for feedback on 
the peer-review panel reports and proposed changes. Nevertheless, NMFS 
believes that the IHA process allows NMFS to receive the benefit of 
important input from the public, subsistence users, and peer review in 
its decision making.

Impact Analysis

    Comment 4: Shell notes that the functional hearing frequency ranges 
provided in the Federal Register notice for the proposed IHA are 
inconsistent with those presented in Southall et al. (2007), 
specifically, the low frequency and pinniped hearing groups. Shell 
states that the extension of the hearing range of low-frequency 
cetaceans is not supported by empirical evidence. Shell argues that 
there is no evidence indicating that mysticetes hear above 20-22 kHz, 
and there are no empirical data to support expansion to 30 kHz. Shell 
also notes that these ranges appear to be drawn from NMFS' draft 
acoustic criteria, which are still under review and have not been 
finalized. Shell requests NMFS provide justification for the ranges 
listed above including associated references.
    Response: The hearing frequency ranges of functional hearing groups 
provided in the Federal Register notice is based on current data (via 
direct measurements [behavioral and electrophysiological]) and 
predictions (based on inner ear morphology, behavior, vocalizations, or 
taxonomy), which indicate that not all marine mammal individuals/
species have equal hearing capabilities, in terms of absolute hearing 
sensitivity and the frequency band of hearing (Richardson et al. 1995; 
Wartzok and Ketten 1999; Southall et al. 2007; Au and Hastings 2008). 
Hearing has been directly measured in a multitude of odontocete and 
pinniped species (see review in Southall et al. 2007). Direct 
measurements of mysticete hearing are lacking (e.g., there was an 
unsuccessful attempt to directly measure hearing in a stranded gray 
whale calf by Ridgway and Carder 2001). Thus, scientifically based 
hearing predictions for mysticetes are based on other scientific 
methods (e.g., anatomical studies: Houser et al. 2001; Parks et al. 
2007; vocalizations: See reviews in Richardson et al. 1995; Wartzok and 
Ketten 1999; Au and Hastings 2008; taxonomy and behavioral responses to 
sound: Dahlheim and Ljungblad 1990; see review in Reichmuth 2007).
    To more accurately reflect marine mammal hearing capabilities, 
Southall et al. (2007) recommended that marine mammals be divided into 
functional hearing groups based on measured or estimated functional 
hearing ranges. Based on additional data, NOAA modified the functional 
hearing groups proposed by Southall et al. (2007) for species relevant 
to this action as follows:

     Extension of upper end of low-frequency cetacean 
hearing range: NOAA extended slightly the estimated upper end of the 
hearing range for low-frequency cetaceans, from 22 to 25 kHz, based 
on data from Watkins et al. (1986) for numerous mysticete species 
(variety of mysticete species responding to sounds up to 28 kHz), Au 
et al. (2006) for humpback whales (songs having harmonics that 
extend beyond 24 kHz), Lucifredi and Stein (2007) for gray whales 
(reported potentially responding to sounds beyond 22 kHz), and an 
unpublished report (Ketten and Mountain 2009) and data (Tubelli et 
al. 2012) for minke whales (predicted hearing range of up to 30 kHz 
based on inner ear anatomy). These new data indicate that at least 
some mysticete species can hear above 22 kHz. Thus our current 
understanding of low-frequency cetaceans' hearing range is 7 Hz-25 
kHz. As more data become available, these estimated hearing ranges 
may require future modification.
     Division of pinnipeds into phocids and otariids: NOAA 
subdivided pinnipeds into their two families: Phocidae and 
Otariidae. Based on a review of the literature, phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al. 2006; Kastelein et al. 2009; Reichmuth et al. 
2013). This is believed to be because phocid ears are anatomically 
distinct from otariid ears in that phocids have larger, more dense 
middle ear ossicles, inflated auditory bulla, and larger portions of 
the inner ear (i.e., tympanic membrane, oval window, and round 
window), which make them more adapted for underwater hearing 
(Terhune and Ronald 1975; Kastak and Schusterman 1998; Hemil[auml] 
et al. 2006; Mulsow et al. 2011; Reichmuth et al. 2013).

    NMFS considers this classification reflects the incorporation of 
the best scientific information since Southall et al. 2007, and is 
considered in our effects analyses for marine mammal incidental take 
authorizations.
    Comment 5: The Commission noted that when estimating the number of 
bowhead takes, Shell assumed that 50 percent of all bowheads would 
avoid the Level B harassment zone during exploratory drilling and 
related support activities. The Commission generally does not agree 
with using assumptions of marine mammal avoidance of certain activities 
when estimating takes, unless the studies supporting such assumptions 
were based on the same or very similar circumstances and NMFS has 
determined that such avoidance would not result in an abandonment or 
significant alteration of behavioral patterns. The Commission further 
states that if NMFS intends to adjust take estimates based on assumed 
levels of avoidance, the Commission recommends that NMFS should provide 
guidance and follow a consistent approach in the adjustment of those 
estimates.
    Response: NMFS agrees with the Commission that general avoidance by 
marine mammals of an ensonified area is a form of Level B harassment. 
Therefore, NMFS worked with Shell and revised the bowhead whale take 
analysis, which is provided in details below. While we agree that 
avoidance

[[Page 35747]]

occurs, the revised take estimate of bowhead whales assumes that the 
animals that avoid the area will be taken by Level B harassment. In 
short, the 50% adjustment to Level B take numbers for avoidance is no 
longer applied.
    Separately, however, NMFS also recognizes that the approach used 
here, which includes consideration of the number of days, results in an 
overestimate of takes, because it assumes a 24-hour turnover rate of 
bowhead whales in the ensonified area. This is not likely due to the 
large area of the Level B harassment zone (modelled at 22 km radius for 
anchor handling) and the slow migration speed of bowhead whales (Mate 
et al. 2000) and observed feeding behavior in the area. Tagging studies 
showed that bowhead whales moved at speeds between 1.1 and 5.8 km/h, 
with frequent stay at places to feed (Mocklin 2009). Although a precise 
quantitative assessment of the turnover rate is difficult due to large 
variation among individual whales, NMFS considers it reasonable yet 
conservative to assume an averaged 48-hour turnover rate for bowheads 
in the ensonified area when estimating bowhead whales that could be 
taken by Level B harassment.
    Comment 6: Citing NMFS' impact analysis when issuing an IHA to 
Shell to take marine mammals incidental to exploratory drilling in the 
Beaufort Sea (77 FR 27284, 27288 [May 9, 2012]), Shell requests that 
NMFS continue to recognize the scientific evidence for avoidance of 
bowhead whales from drilling related activities, and not deviate from 
its prior position in 2012, which asserted that avoidance does not 
always rise to a level that constitutes a Level B take.
    Response: NMFS recognizes that some marine mammals will avoid 
drilling related activities to differing degrees. Further, there may be 
some small degree of avoidance that occurs at lower received levels 
that would not rise to the level of a take; however, avoidance that is 
expected, or modeled, within or near the 160-dB isopleth (where there 
are data illustrating notable avoidance responses (Richardson et al., 
1995)) is considered behavioral harassment. Therefore, it is 
inappropriate to suggest that some portion of animals that would 
otherwise be expected to be exposed within the 160-dB isopleth be 
considered not taken because they would avoid the area--as the 
avoidance itself is a form of Level B harassment. Because Shell 
proposed to quantitatively adjust their estimated level B take numbers 
in their application, it was necessary for NMFS to further interpret 
this issue, however, we consider this a clarification rather than a 
deviation from what was included in the 2012 notice.
    Comment 7: NAEC, AWL, and a form letter from private citizens state 
that Shell's activities would harm more than small numbers of marine 
mammals or that the impacts will be more than negligible. EIA states 
that Shell's proposed ice management activities will expose an 
unacceptable number of belugas to harassing levels of noise.
    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. With the exception of the ringed seal, less 
than 5.1% of each species stock or population would be taken by Level B 
harassment incidental to Shell's activities. The modeling results 
indicate that 8.4% of the ringed seal population would be taken by 
Level B harassment. For bowhead, gray, and beluga whales, NMFS further 
consulted with the National Marine Mammal Laboratory and NMFS Alaska 
Regional Office and revised the estimated takes using a more robust 
dataset. The results show that except for beluga whale, the estimated 
takes of bowhead and gray whales are further reduced to 5.5% and 4.4% 
of their population from the previous estimates of 13.2% and 13.5%, 
respectively. For beluga whales, the revised take estimate is 1,662 
instead of 974 animals. Further breakdown of stock specific takes 
provide a result of 344 animals (9.3%) of the East Chukchi Sea stock 
and 1,318 animals (3.4%) of the Beaufort Sea stock. A detailed 
description of the take calculation on beluga whales is provided in 
section ``Estimated Takes'' below. We also note the following important 
factors:
    (1) In all of the modeling submitted by Shell, a 1.3 dB safety 
factor was added to the source level of each continuous sound source 
prior to sound propagation modeling of areas exposed to Level B 
thresholds, which make the effective zones for take calculation larger 
than they likely will be;
    (2) Shell applied binning of similar activity scenarios into a 
representative scenario, each of which reflected the largest exposed 
area for a related group of activities;
    (3) Except for bowhead whale, the take estimates assume 100% daily 
turnover of population for all other species, which likely 
overestimates the number of different individuals that would be 
exposed, especially during non-migratory periods. Even for the bowhead 
whale, which is slow moving and often observed stopping to feed during 
its fall migration, a 50% daily (i.e., 48-hour) turnover of population 
was included in take calculation; and
    (4) Density estimates for some cetaceans include nearshore areas, 
where more individuals would be expected to occur than in the offshore 
Burger Prospect area (e.g., gray whales).
    Based on this analysis, NMFS concluded that takes resulting from 
Shell's activities will constitute small numbers of marine mammals of 
the affected species or stocks.
    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 notice 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: NAEC states that the take thresholds NMFS uses are 
outdated.
    Response: NMFS does not agree with NAEC's statement. NMFS uses 160 
dB (rms) as the exposure level for estimating Level B harassment takes 
for impulse noise source and 120 dB (rms) for non-impulse noise source. 
These thresholds were established based on measured avoidance responses 
observed in whales in the wild. Specifically, the 160 dB threshold was 
derived from data for mother-calf pairs of migrating gray whales (Malme 
et al., 1983, 1984) and bowhead whales (Richardson et al., 1985, 1986) 
responding to seismic airguns (e.g., impulsive sound source). While the 
120 dB threshold is a more conservative threshold for non-impulse 
sources (e.g., drilling) given that these sources have longer duration 
than impulsive noises and thus most likely longer than the integration 
time needed for acoustic detection by an animal.
    We acknowledge there is more recent information bearing on 
behavioral reactions to seismic airguns, but those data only illustrate 
how complex and context-dependent the relationship is

[[Page 35748]]

between the two. See 75 FR 49710, 49716 (August 13, 2010) (IHA for 
Shell seismic survey in Alaska; response to comment 9). Accordingly, it 
is not a matter of merely replacing the existing threshold with a new 
one. NOAA is working to develop relatively more sophisticated draft 
guidelines for determining acoustic impacts, including information for 
determining Level B harassment thresholds. Due to the complexity of the 
task, the draft guidelines will undergo a rigorous review that includes 
internal agency review, public notice and comment, and external peer 
review before any final product is published. In the meantime, and 
taking into consideration the facts and available science, NMFS 
determined it is reasonable to use the 160 dB and 120 dB thresholds for 
estimating takes of marine mammals in the Chukchi Sea by Level B 
harassment. However, we discuss the science on this issue qualitatively 
in our analysis of potential effects to marine mammals.
    Comment 9: EIA states that Shell's application (1) relies on 
outdated beluga population data, (2) conflates resident and migratory 
populations, and (3) utilizes faulty beluga survey methods.
    Response: NMFS does not agree with EIA's statement. First, the 
beluga whale densities used to estimate potential exposure were 
calculated from aerial survey data collected by the National Marine 
Mammal Laboratory (NMML) from July through October of 2008-2014. These 
are the best scientific information available for the impact analysis. 
Second, there is no ``resident'' population of beluga whale in the 
Chukchi Sea as stated by the EIA's comment. When analyzing potential 
impacts to beluga whales that could result from Shell's proposed 
exploration drilling activity, we reviewed the available information on 
stock structure, migratory behavior, and density of the beluga whale 
Eastern Chukchi Sea Stock and the Beaufort Sea Stock in the Chukchi Sea 
and made judgments based on that information.
    Comment 10: EIA states that Shell's proposed noise mitigation 
measures fail to take into account the sensitivity of belugas to noise, 
particularly airgun-related noise. EIA further points out that in 
Shell's IHA application, belugas are not afforded the greater levels of 
mitigation that Shell's proposal gives larger whales. For example, upon 
sighting a beluga, airgun testing is not allowed to resume for 15 
minutes, as opposed to the longer 30-minute pause for larger whales.
    Response: The apparent sensitivity of belugas to anthropogenic 
sounds in certain circumstances/locations means that beluga whales are 
unlikely to occur within the exclusion zone around an operating airgun. 
Nevertheless, to be consistent with other Arctic open-water activities 
for which NMFS issues take authorizations, NMFS changed the IHA to 
require that should a beluga occur within an exclusion zone during 
airgun operations, the longer 30-minute pause will be required if the 
animal is not sighted exiting the exclusion zone.
    Comment 11: The AWL states that there are large gaps in basic 
scientific information about both the Chukchi Sea ecosystem and marine 
mammal responses to noise, and that these gaps prevent adequate 
analysis of the potential impacts of Shell's proposed activities on 
wildlife.
    Response: As required by NMFS' 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 a 
negligible impact on the affected marine mammal species or stock. While 
NMFS agrees that there may be some gaps in information about the 
Chukchi Sea ecosystem and in our understanding of how some taxa respond 
to noise in certain situations, at this point, results from many 
studies illustrate well the range of likely responses to industrial 
noise across a wide variety of species (Southall et al. 2007; LGL et 
al. 2014). Much of this work on the Arctic species addressed here has 
been conducted as part of the monitoring requirements of previous MMPA 
authorizations (e.g., HDR 2013; Beland et al. 2013; Reider et al. 
2013). In order to issue the IHA to Shell, NMFS conducted rigorous 
analyses using the best available scientific information about both the 
Chukchi Sea ecosystem and marine mammal responses to noise, and we are 
confident that the content of this extensive dataset supports our 
findings. These analyses are provided in the Federal Register notice 
(80 FR 11726; March 4, 2015) for the proposed IHA and EA prepared by 
NMFS.
    Industrial activities have been occurring (at varying levels) in 
the U.S. Arctic Ocean for decades, and the available measurable 
indicators do not suggest that these activities are having long-term 
impacts on marine mammal species/stocks in the area. 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. This increase has been observed to 
continue to date (Givens et al. 2013). 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' negligible 
impact finding is supported by the available facts and science.
    Comment 12: The AWL states that NMFS uses outdated thresholds for 
acoustic impact analysis, and that the new criteria will likely 
increase the estimated number of bowhead whales, other cetaceans, and 
ice seals that could be disturbed by exploratory activities, and in 
some cases the increased level of disturbance could be large.
    Response: The AWL did not specify in its comment whether it was 
referring to Level A or Level B harassment thresholds. Nevertheless, 
NMFS does not agree with AWL's assessment. First, for Level A takes, 
NMFS' proposed draft guidance for acoustic injury criteria use a 
different set of metrics than the current criteria, meaning that one 
cannot simply compare 180 dB to the numbers proposed in the draft 
acoustic guidance. The proposed criteria have a duel metric of both 
peak pressure as sound pressure level (SPL) and sound exposure level 
(SEL), while the current acoustic criteria use root-mean-squared (RMS) 
as SPL. Additionally, the draft guidance for injury also include taxa-
specific filters that must be applied in order to apply the new 
thresholds, making it even more difficult to compare directly to the 
current 180-dB threshold.
    Second, Shell's proposed exploration drilling will result in Level 
B harassment takes only, and Level B behavioral harassment thresholds 
are not addressed in NMFS' draft acoustic threshold guidance. As 
indicated elsewhere in this Federal Register Notice, NMFS is working to 
develop guidance on updated behavioral take thresholds but NMFS 
believes the current thresholds are still appropriate. See response to 
Comment 8.
    Comment 13: 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.
    Response: For non-impulse 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,

[[Page 35749]]

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 10-14 hours for each survey, 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, when predicting take estimates for incidental take 
authorizations NMFS does not consider that these exposures rise to the 
level of a take. 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 occurred 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. For predictive purposes, NMFS therefore continues to estimate takes 
from impulse noises such as seismic using the 160 dB (re 1 [mu]Pa) 
threshold.
    According to experts on marine mammal behavior, whether a 
particular stressor could potentially disrupt behavioral patterns of 
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 are intended to assist in a reasonably accurate 
assessment of take while acknowledging that sometimes animals will 
respond at received levels below those levels and sometimes they will 
not respond in a manner considered a take at received levels above 
them.
    Comment 14: The AWL disagree with NMFS assessment that ``few seals 
are expected to occur in the proposed project area'' and that ``Shell's 
proposed activities would occur at a time of year when the ice seal 
species found in the region are not molting, breeding or pupping.'' The 
AWL states that these statements are not supported. AWL states that 
Shell's proposed ice management and ice-breaking activities have the 
potential to disrupt essential ringed seal molting activities in July 
in a large region surrounding the drilling site, which could have 
harmful consequences for ringed seal survival.
    Response: The breeding and pupping season for Arctic ringed seal 
populations occurs from late March to mid-May, well before the proposed 
July 1 start date and after the conclusion of operations at the end of 
October (Kelly et al. 2010). Although molting in some areas of the 
Arctic can extend into July, the molting period for ringed seals in the 
Chukchi Sea is primarily in May and June. This is evidenced by when the 
National Marine Mammal Laboratory conducted aerial surveys for ringed 
and bearded seals in 1999 and 2000, the surveys occurred in late May 
and early June at the peak of the molting/basking period (Bengtson et 
al. 2005). Therefore, ice scouting and management activities in July 
and August, should they be necessary, will not occur during the period 
when most molting occurs. In addition to the fact that these activities 
are not expected to overlap with molting times, it is important to note 
that a large percentage of the anticipated takes will occur as a result 
of exposures that only just exceed the harassment threshold (e.g., 
about 67% of the takes would be as a result of exposures between 120 
and 126 dB), suggesting relatively minor and shorter term impacts that 
would have little to no likelihood of affecting an individual's 
fitness. Additionally, the estimated takes represent instances of take 
and do not account for the fact that the same individuals may be taken 
on more than one day, so the numbers of takes are an overestimate of 
individuals.
    Comment 15: The AWL states that ice management and ice-breaking 
activities, vessel traffic, and noise disturbance in September and 
October have the potential to displace large numbers of ringed seals 
and prevent them from occupying wintering areas and breeding areas in 
the offshore pack ice, with potential harm to survival.
    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 (80 FR 11726; March 4, 2015) in the section regarding 
anticipated effects on marine mammal habitat. NMFS noted that use of 
the icebreakers would occur outside of the ringed seal breeding and 
pupping seasons in the Chukchi Sea, and those ringed seal activities 
occur more commonly on landfast ice, which will not be affected by 
Shell's activity. 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 
notice, NMFS determined that this activity and these reactions would 
result in Level B harassment.
    In addition, ice formation in October could begin to support haul-
out of seals; however, wind and currents continually move and reshape 
the sea ice throughout the late-fall and early winter period. This 
movement of the pack ice continually opens new leads and breathing 
holes while closing old ones. Because the offshore pack ice continues 
to move and change throughout the winter and spring, breathing holes 
established in October, as described in shorefast ice locations, are 
unlikely to persist through the winter. Any disruption of newly forming 
sea ice in October by project vessels is not likely to cause any 
greater disturbance to the pack ice environment than will occur

[[Page 35750]]

through natural processes during the remainder of the ice-covered 
period.

Mitigation, Monitoring and Reporting

    Comment 16: The Commission notes that Shell would be required to 
monitor for marine mammals for 30 minutes before and continuously 
during airgun operations, but no post-activity monitoring. The 
Commission states that post-activity monitoring is needed to ensure 
that marine mammals have not been taken in unexpected or unauthorized 
ways or in unanticipated numbers. The Commission further states that 
some types of taking (e.g., taking by death or serious injury) may not 
be observed until after the activity has ceased. Accordingly, the 
Commission recommends that NMFS require Shell to monitor for marine 
mammals for 30 minutes before airgun operations begin, while those 
activities are being conducted, and for 30 minutes after those 
operations have ceased.
    Response: NMFS agrees with the Commission's recommendation and 
revised the proposed IHA to require post-activity marine mammal 
monitoring for 30 minutes after Shell ceases activities.
    Comment 17: The Commission recommends that NMFS incorporate the 
peer review panel's recommendations into the IHA if issued.
    Response: NMFS conducted a peer review process to evaluate Shell's 
monitoring plan in early March 2015 in Anchorage, AK. The peer review 
panel submitted its report to NMFS in early April and provided 
recommendations to Shell. The panel's major recommendation was for 
Shell to modify the configuration of it passive acoustic arrays to 
evaluate the potential for spatial displacement of marine mammals. The 
panel also requested that the 90-day monitoring report include 
sightability curves for each species observed in the study area, and 
report concurrent collection of spatially overlapped visual and 
acoustic data to allow for a more detailed description of approximate 
acoustic detection ranges for the different species sighted and 
acoustically detected.
    In addition, though not requested, the peer review panel also 
provided additional mitigation measures for bowhead whales or other 
large whale cow/calf pairs and aggregations, and during low visibility 
conditions; limiting the duration of mitigation gun to 30 minutes 
during repositioning; and turning off engines when vessels are 
stationary.
    NMFS discussed with Shell the peer review panel report and went 
through a list of recommendations. As a result, Shell agrees to modify 
the deployment configuration of its passive acoustic monitoring to 
allow for evaluation of potential for spatial displacement of marine 
mammals. Shell also agreed to provide sightability curves and 
overlaying visual and acoustic detections in its 90-day report.
    Regarding the mitigation measures recommended by the panel, Shell 
advised, and we agree, that the measures would not be practicable. For 
example, the VSP is planned to be conducted for just 10-14 hours total 
at different sediment depths at each site; a shutdown for cow/calf 
pairs and aggregation of bowhead whales and other large whales and 
during low visibility conditions would require Shell to restart the 
VSP, thus extending the duration of the VSP. In addition, the panel's 
recommended mitigation measures for turning off vessel engines while 
stationary would pose safety concerns. Therefore, these additional 
measures were not included in the IHA.
    A detailed discussion on the peer review process and 
recommendations is provided in ``Monitoring Plan Peer Review'' section 
below.
    Comment 18: The NSB requests NMFS ensure that sufficient monitoring 
and mitigation requirements be implemented, and their effectiveness 
verified, to protect subsistence species, habitat and subsistence 
hunters. In addition, the NSB requests NMFS ensure that appropriate 
acoustic and visual monitoring be required.
    Response: Under the MMPA, NMFS must determine the taking from the 
specified activity will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). In addition, NMFS is required to prescribe the 
permissible methods of taking and other means of effecting the least 
practicable impact on the species or stock and their habitat and on the 
availability of the species or stock for taking for subsistence uses, 
as well as requirements pertaining to the monitoring and reporting of 
such takings.
    Shell has worked with NMFS, as well as the affected subsistence 
communities, for multiple years on the continued development of its 
4MP. The iterative evolution and review of the 4MP and its results 
indicates successful implementation by Shell, supports NMFS' impact 
analyses for this activity (i.e., from the information gathered, 
impacts are within the scope and extent of those previously estimated) 
and, further, has added meaningfully to our understanding of the 
impacts of industrial activities on marine mammals. NMFS has conducted 
its own rigorous review and analysis of Shell's 4MP, and also had 
Shell's monitoring plan peer-reviewed by an independent peer-review 
panel (see below). Furthermore, the effectiveness of these monitoring 
and mitigation measures were evaluated by NMFS from Shell's 2012 
monitoring reports, and deemed to be effective to protect subsistence 
species, habitat, and subsistence hunters.
    These processes led NMFS to conclude that sufficient monitoring and 
mitigation requirements are prescribed in the IHA issued to Shell to 
protect subsistence species, habitat, and subsistence hunters. In 
addition, the IHA contains appropriate acoustic and visual monitoring 
requirements.
    Comment 19: Shell requests clarification on PSO monitoring 
requirement in the proposed IHA to reflect the 4MP to read:
    ``Utilize two, NMFS-approved vessel-based Protected Species 
Observers (PSOs) (except during meal times and restroom breaks, when at 
least one PSO will be on watch) aboard the drilling units to visually 
watch for and monitor marine mammals near the drilling units or support 
vessel during active drilling or airgun operations . . . day or night. 
At least one PSO will be aboard each support vessel to conduct watch.''
    Response: NMFS made the modification to clarify the PSO monitoring 
requirements and updated the language in the final IHA based on Shell's 
request.
    Comment 20: Regarding the requirement of making ZVSP sound source 
verification (SSV) measurements available to NMFS in 120 hours, Shell 
is concerned that this proposed requirement poses considerable safety 
issues and operations challenges. Shell stated that some of the 
recorders required to measure sound threshold radii of the ZVSP airgun 
array must be moored to the seafloor within the anchor pattern of the 
drilling unit. Recovery of these recorders while the drilling unit 
remains anchored will be unsafe. Grappling, the most reliable method of 
recovery, or recovery by acoustic release of the recorders, introduce 
risks to the crew of the drilling unit and the recovery vessel. These 
risks include entanglement of grappling lines with anchor lines, and 
disruption or disablement of critical communications equipment from 
acoustic interference. In addition, Shell states that it would conduct 
at most only one more ZVSP survey following measurement of the ZVSP 
airgun array,

[[Page 35751]]

and the ZVSP survey is only 10-14 hours in duration.
    Response: After further review of Shell's proposed specific 
activities and discussion with Shell, NMFS agrees with Shell's concern 
and removed the condition of requiring ZVSP SSV results 120 hours after 
the measurement. Instead, NMFS requires that ZVSP SSV results be made 
available in the 90-day monitoring report. NMFS further recognizes that 
the ZVSP acoustic footprint proposed by Shell for 2015 was modeled 
using JASCOs Marine Operations Noise Model, which is a reliable 
computation model for underwater acoustic propagation assessment. These 
model results were maximized over all water depths to identify the most 
protective 95th percentile distances to Level A thresholds, and then 
multiplied by 1.5 as an additional safeguard to ensure sufficient 
establishment of ZVSP exclusion zones for monitoring and mitigation. 
For these reasons, NMFS considers the modeled pre-season Level A 
exclusion zones adequate to protect marine mammals from injury.
    Comment 21: Shell requests NMFS remove the SSV reporting condition 
in the proposed IHA, which requires that:
    ``Preliminary vessel characterization measurements will be reported 
in a field report to be delivered 120 hours after the recorders are 
retrieved and the data downloaded.''
    Shell states that it did not intend to include this requirement in 
the IHA application. Shell argues that one of its 2015 sound source 
characterization (SSC) of its exploration drilling program is a 
comprehensive analysis of underwater sound across the entire 
operational season, which necessitates that recorders remain deployed 
as long as is practicable. Further, Shell states that there is no 
connection between measurements of vessel sounds and mitigation, and 
Shell does not believe there is anything to be gained by reporting 
preliminary vessel measurements prior to a more comprehensive analysis 
of the data. Finally, Shell states that it will present detailed 
results of drilling and vessel SSCs in the 90-day report, as stated in 
the proposed IHA.
    Response: The proposed SSC reporting measurements was initially 
proposed by Shell in its 4MP. However, NMFS agrees with Shell's comment 
that leaving these recorders deployed for the entire project duration 
will collect valuable acoustic data on underwater noise across the 
entire operational season. NMFS made revision to the SSC condition in 
the IHA issued to Shell that requires Shell to present detailed results 
of drilling and vessel SSCs in its 90-day report.
    Comment 22: Shell points out that the following two proposed IHA 
mitigation measures regarding vessel movement seem to be contradictory:
    ``Avoid multiple changes in direction and speed when within 900 
feet (300 yeards/274 m) of whales.'' (7(b) of the proposed IHA)
    ``When weather conditions require, such as when visibility drops, 
support vessels must reduce speed and change direction, as necessary 
(and as operationally practicable), to avoid the likelihood of injury 
to whales.'' (7(c) of the proposed IHA)
    Shell states that the first proposed requirement is sufficient to 
meet mitigation objectives and avoid injury to whales, and requests 
NMFS to remove the second proposed requirement.
    Response: NMFS does not agree with Shell's assessment. The first 
proposed requirement (7(b) of the proposed IHA) would be in effect when 
a whale is sighted within 900 feet (300 yards/274 m) of a moving vessel 
and refers to avoiding multiple changes in direction in speed. In 
addition, 7(a) of the proposed IHA further requires all vessels to 
reduce speed to a maximum of 5 knots when a whale is detected at this 
distance. Item 7(c) is a general requirement for vessel transiting 
during poor visibility. Under this condition, vessels are required to 
travel at a reduced speed even no whale is in sight. NMFS believes that 
this condition is necessary to compensate for reduced whale 
detectability during poor visibility, to avoid ship strike. The IHA 
issued to Shell includes all these requirements.
    Comment 23: Shell points out that an important ZVSP mitigation 
measure was omitted from the proposed IHA that has been included in 
previous Arctic IHAs for marine seismic surveys. Shell recommends that 
the following mitigation measure be included in the IHA:
    ``If, for any reason, electrical power to the airgun array has been 
discontinued for a period of 10 minutes or more, ramp-up procedures 
shall be implemented. Only if the PSO watch has been suspended, a 30-
minute clearance of the exclusion zone is required prior to commencing 
ramp-up. Discontinuation of airgun activity for less than 10 minutes 
does not require a ramp-up.''
    Response: NMFS agrees and included this measure in the final IHA 
issued to Shell.
    Comment 24: Shell states that the following language regarding PSOs 
is confusing:
    ``The Holder of this Authorization shall designate biologically-
trained PSOs to be aboard the drilling units and all transiting support 
vessels.''
    Shell states that the confusion lies between an academically 
degreed biologist and non-degreed biologist, both of which when 
properly trained can perform the duties of a PSO. Shell suggests we 
change the language to:
    ``The Holder of this Authorization shall designate trained PSOs 
aboard drilling units, icebreakers, and anchor handlers. All support 
vessels will be staffed with at least one trained PSO.''
    Response: NMFS agrees and revised the PSO language per Shell's 
recommendation. ``Trained'' requires that PSOs attend the training 
session described in this Federal Register Notice shortly before the 
start of the 2015 drilling season.
    Comment 25: The AWL states that the mitigation measures NMFS has 
proposed are inadequate for protecting marine mammals from adverse 
impacts. The AWL further states that NMFS has failed to analyze the 
full range of available mitigation measures, especially with regard to 
time/area restriction. The AWL specifically mentioned Hanna Shoal and 
migration corridors.
    Response: In order to issue an incidental take authorization (ITA) 
under the MMPA, NMFS must, where applicable, set forth the permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses (where relevant).
    Concerning time/area closure, the IHA issued to Shell contains 
specific spatio-temporal requirements that Shell must follow to 
minimize or avoid impacts to subsistence harvest. Under the IHA issued 
to Shell, Shell is not permitted to enter the Chukchi Sea prior to July 
1, 2015, which helps minimize impacts to the beluga hunt. In addition, 
Shell must finish drilling activities by October 31, 2015, which helps 
ensure that the drill ship and supporting vessels depart past Saint 
Lawrence Island before the Gambell bowhead whale harvest begins, thus 
minimizing potential impacts.
    Regarding Hanna Shoal, we reviewed the literature and determined 
that although it has biological significance for walrus, a U.S. Fish 
and Wildlife species, there are no species under NMFS' jurisdiction for 
which Hanna Shoal has particular biological

[[Page 35752]]

importance. AWL did not mention other specific time/area closures.
    One new publication compiles cetacean behavioral and distributional 
information to identify biologically important areas that are 
specifically used for feeding, migrating, or reproductive uses, or 
where small and resident populations are limited. Part of the 
northeastern Chukchi Sea is recognized as a bowhead whale reproductive 
biologically important area (BIA) from observation of calves there in 
October (Clarke et al. 2015). Additionally, bowhead whales have also 
been observed feeding in this area during summer and fall; however, it 
is not recognized as a feeding BIA due to relatively fewer feeding 
observations (Clarke et al. 2015). Additionally, in the northeastern 
Chukchi Sea, aerial survey sightings (Clarke & Ferguson, 2010; Clarke 
et al. 2011, 2012, 2013), satellite telemetry (Quakenbush et al., 
2010a, 2010b, 2013), and passive acoustic data (Hannay et al., 2013) 
indicate that the migration route in September and October is 
geographically broad (from the coast to > 400 km offshore); therefore, 
the northeastern Chukchi Sea does not meet the criteria for a migratory 
corridor BIA (Clarke et al. 2015).
    Portions of these areas utilized by bowhead whales for calving, 
feeding, and migration would be ensonified by Shell's proposed 
exploration drilling operation, although the size of the ensonified 
area will vary depending on the particular activity (e.g., drilling, 
anchor handling, ZSVP, etc.). NMFS has considered time/area-based 
mitigation to reduce potential impacts to bowhead whale reproduction, 
feeding, and migration in regard to its BIAs. The only BIA that 
overlaps with Shell's exploration drilling is the bowhead reproduction 
BIA in the northeast Chukchi Sea in October and NMFS has already 
considered and discussed the potential for some small amount of 
behavioral harassment of mothers and calves, should they pass nearby 
the comparatively small area that may be ensonified by Shell's 
activities. Since Shell would only be conducting exploration drilling 
during a short four-month period, imposing a time/area limit of one 
month to avoid this time when calves might pass would mean a 25% 
reduction of Shell's work window, and would only likely avoid a small 
amount of harassment of mother/calf pairs. On balance, when the limited 
benefits of the measure are compared against the negative impacts to 
Shell's activities (either not completing the needed activities, or 
needing to extend them into additional seasons), NMFS considers it 
impracticable for the company to implement.
    NMFS' analysis of the potential impacts of Shell's proposed 
exploration drilling on marine mammals species/stocks and subsistence 
activities indicates that Shell's activities would be limited to a 
small area in the Chukchi Sea during a four-month period in the 2015 
open-water season. This is relatively small in both spatial and 
temporal scales when considering the total area of the Chukchi used by 
the affected marine mammal species or stocks for various activities, 
including migration.

NEPA Analysis

    Comment 26: The AWL states that NMFS must address cumulative, long-
term effects of increased noise and other impacts from oil and gas 
activity properly before further activity is authorized.
    Response: 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 for an IHA, 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.
    Neither the MMPA nor NMFS' implementing regulations specify how to 
consider other activities and their impacts on the same populations 
when conducting a negligible impact analysis. However, consistent with 
the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into the negligible impact 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the density/distribution and status of the species, 
population size and growth rate, and ambient noise). Additionally, NMFS 
analyzed cumulative effects in NMFS' EA for the ``Issuance of an 
Incidental Harassment Authorization for the Take of Marine Mammals by 
Harassment Incidental to Conducting an Exploration Drilling Program in 
the U.S. Chukchi Sea'' 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.
    NMFS considered the impacts analyses (i.e., direct, indirect, and 
cumulative) contained in the EA and other relevant NEPA documents cited 
in our response to comment 27 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 with no 
likely consequences for annual rates of recruitment or survival 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 mammal species or stocks or their habitats.
    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 2014 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

[[Page 35753]]

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.
    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 have 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.
    Comment 27: NAEC states there is a lack of programmatic analysis of 
the effects of oil and gas exploration and development in the Arctic. 
Oceana claims that a programmatic environmental impact statement is 
needed to evaluate the environmental impacts of proposed and reasonably 
foreseeable oil and gas exploration in the Beaufort and Chukchi Seas. 
Both Oceana and AWL state that NMFS should not rely on an EA to 
evaluate the impacts of the proposed IHA.
    Response: NOAA prepared a Supplemental Draft Environmental Impact 
Statement on the Effects of Oil and Gas Activities in the Arctic Ocean 
(DEIS). The DEIS includes a broad range of potential offshore oil and 
gas activities in the Arctic that could affect marine mammals, other 
resources, and Alaska Native communities. While this EIS has not been 
finalized, and further considers a program including a more extensive 
amount of activity than is currently occurring, NMFS considers the 
analyses contained therein in the cumulative impact assessment of the 
current EA for the activity assessed here.
    NMFS prepared an EA in 2012 to consider the effects of our 2012 
IHAs for drilling in the Beaufort and Chukchi Seas, pending 
finalization of that EIS. For this IHA we prepared an EA, under similar 
reasoning we used in 2012. While the Final EIS is still under 
development, NMFS conducted a thorough analysis of the affected 
environment and the environmental consequences from exploratory 
drilling in the Chukchi Sea in 2015 and prepared an EA specific to 
Shell's proposed activity. The analysis in that EA warranted a Finding 
of No Significant Impact for issuance of an IHA to Shell for the 
incidental taking of marine mammals in the Chukchi Sea in 2015
    In addition, BOEM prepared a Supplemental EIS (SEIS), published in 
February 2015, to analyze its estimate of the highest amount of 
production that could reasonably result from its Lease Sale 193. 
Information provided in our joint DEIS and BOEM's SEIS was considered 
in evaluating Shell's proposed exploration drilling impacts. In short, 
NOAA has considered the programmatic impacts and cumulative effects of 
multiple oil and gas exploration activities through multiple documents 
and analyses, the substance and conclusions (preliminary or final) of 
which have been considered in the current NEPA analysis for this 
action.
    Comment 28: While applauding NMFS for treating the no action 
alternative as a true no action alternative in its draft EA, and that 
for inclusion of two realistic alternatives that include fewer impacts 
than the preferred alternative, the AWL states that NMFS could explore 
a wider range of alternatives, including an alternative that requires 
the closures of particular areas.
    Response: In AWL's comments, it suggested Hanna Shoal could be 
considered for time/area closure. However, as discussed in Response to 
Comment 25, Hanna Shoal is not an important habitat for marine mammals 
under NMFS' jurisdiction, and the IHA contains other spatio-temporal 
restrictions that bound its effective dates. The alternatives NMFS 
considered in its draft EA are: (1) Issuance of an authorization with 
mitigation measures (Preferred Alternative); (2) Issuance of an IHA for 
a shorter time period with required mitigation, monitoring, and 
reporting requirements (Alternative 2); (3) Issuance of an IHA to drill 
one well with required mitigation, monitoring, and reporting 
requirements (Alternative 3); and (4) No issuance of the request IHA to 
Shell for its exploration drilling activities (Alternative 4--the No 
Action Alternative). Other alternatives considered but rejected from 
further consideration include: (1) Issuance of an IHA with no required 
mitigation, monitoring, or reporting measures; and (2) Use of 
alternative technologies. Since Shell's proposed exploration drilling 
activities in the 2015 Arctic open-water season in Chukchi Sea occupies 
a small area and will have a limited noise footprint around its drill 
platforms and ice management and icebreaking vessels and other support 
vessels around the drilling vicinity, and further that footprint is not 
within an area of heightened importance for marine mammals (with the 
exception to bowhead whale reproduction in October, see Response to 
Comment 25 above) or subsistence uses, NMFS does not consider the 
closure of a particular area would be a meaningful alternative. We also 
note that Alternative 3, issuance of IHA to drill one well with 
required mitigation, monitoring, and reporting requirements, considers 
a spatial limitation on the area Shell would affect.
    Comment 29: AWL states that NMFS draft EA does not contain original 
analysis of cumulative impacts of climate change for this IHA, and that 
the most recent study cited in reference to climate change analysis is 
from 2011.
    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 cumulative 
effects analysis that includes consideration of climate change and 
incorporates by reference several original studies on climate change 
(ACIA 2004; Raven et al. 2005; IPCC 2007; Fabry et al. 2009; Mathis 
2011). An assessment of the IHA for Shell's drilling activity and its 
added contribution to cumulative impacts of climate change on the 
environment was conducted based on these studies. An exhaustive search 
of the most recent studies did not show that NMFS missed any critical 
information in conducting the analysis. In its comment, the AWL did not 
point out any additional new scientific information that NMFS should 
take into consideration in its climate change analysis. We also note 
that climate change is considered in BOEM's SEIS for Lease Sale 193 and 
NMFS' draft EIS for the Arctic.

Impacts on Subsistence

    Comment 30: The AEWC states that the analysis in the Federal 
Register of potential impacts to subsistence uses should begin with a 
discussion of whether the operator has signed the Conflict Avoidance 
Agreement (CAA) and, if so, what the CAA includes as

[[Page 35754]]

mitigation measures for the subsistence activities.
    Response: NMFS has defined ``unmitigable adverse impact'' in 50 CFR 
216.103 as: An impact resulting from the specified activity: (1) That 
is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met. 
The analysis of potential impacts to subsistence uses depends on more 
information than solely whether the applicant has signed a CAA. 
Nevertheless, in our analysis, we did consider the CAA negotiation 
between the Shell and the Native subsistence users. Where measures 
outlined in the CAA are also necessary to ensure an unmitigable adverse 
impact to subsistence uses, NMFS includes them as required measures in 
the IHA. In the Federal Register notice for the proposed IHA, NMFS 
noted that Shell attended the 2012-2014 CAA negotiation meetings in 
support of exploration drilling, offshore surveys, and future drilling 
plans. In addition, Shell informed NMFS that it would do the same for 
the upcoming 2015 exploration drilling program, and Shell has signed 
the 2015 CAA.
    Comment 31: The AEWC notes that the proposed IHA for Shell 
incorporates mitigation measures from the CAA, including the use of 
protected species observers (PSOs) and Inupiat Communicators, the Com-
Centers and the general communications scheme, sound source 
verification, monitoring plans, cumulative noise impacts study, and 
general provisions for avoiding interference with bowhead whales or 
subsistence whale hunting activities. However, AEWC points out that 
additional mitigation measures from the CAA should also be included in 
the IHA, including: Standardized Log Books (CAA Section 204) and Shore-
Based Service and Supply Areas (CAA Section 504). The AEWC recommends 
these measures be included under Section 9 of the IHA.
    Response: NMFS considered whether implementing Standardized Log 
Books and Shore-Based Service and Supply Areas was necessary to reach a 
finding of no unmitigable adverse impact on availability of marine 
mammals for taking for subsistence or appropriate for effecting the 
least practicable impact on the availability of the species or stock 
for taking for subsistence uses, and in both cases determined they were 
not. The recommendation of Standardized Log Books requires that 
industry participants provide the Com-Centers and Marine Mammal 
Observer/Inupiat Communicators with identical log books to assist in 
the standardization of record keeping associated with communications 
procedures. NMFS further clarified with AEWC on this issue and 
understands that the log books would serve a record-keeping function at 
times in determining sources of disturbance by the AEWC. The AEWC would 
like to have a coherent record of activities and communications. The 
AEWC further states that as non-industry vessel traffic increases 
(i.e., research, commercial, and marine tourism vessels), the ability 
to track communications through the Com Centers and along the coast is 
going to become important.
    NMFS has already been requiring Shell and other companies to use 
standardized format for marine mammal monitoring under the 
recommendation by peer-review panel. We again require Shell to provide 
detailed records of all marine mammal sightings and its activities 
under the IHA. In addition, Shell is required to produce a draft 
comprehensive report that integrates the studies into a broad based 
assessment of all industry activities and their impacts, which will be 
made available to NMFS, AEWC, and NSB for review. Furthermore, Shell is 
required to communicate with Com Centers for all its activities that 
could affect subsistence resources. Finally, as Shell already signed a 
CAA with AEWC, this condition prescribed in the CAA will serve as a 
form of agreement between AEWC and Shell on these issues.
    Regarding the Shore-Based Service and Supply Areas provision, NMFS 
reached out to the AEWC for clarification of this recommendation. AEWC 
states that this simply means that the mitigation measures run both 
prospect-to-shore and shore-to-prospect. Therefore, NMFS does not 
believe that this requirement would add additional value to NMFS 
determination of no-unmitigable impact.
    Comment 32: The AEWC requests NMFS include a condition requiring 
Shell to complete exit transit through the Bering Strait to a point 
south of 59 degrees North latitude no later than November 15, 2015. In 
addition, the AEWC requests NMFS require that any industry participant 
vessel that encounters weather or ice that will prevent compliance with 
the date shall coordinate its transit through the Bering Strait to a 
point south of 59 degrees North latitude with the appropriate Com-
Centers, and that all industry participant vessels shall, weather and 
ice permitting, transit east of St. Lawrence Island and no closer than 
10 miles from the shore of St. Lawrence Island.
    Response: Shell signed the 2015 CAA with the AEWC on April 23, 
2015. In the signed 2015 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 and the IHA. Shell's 
IHA is valid for drilling operations through October 31. Therefore, 
demobilization and transit out of the area will begin by that date. 
Information shared with NMFS from hunters on St. Lawrence Island noted 
that the fall bowhead whale hunts typically occur the week of 
Thanksgiving. For example, in 2012, 1 bowhead whale was harvested on 
November 27 and 1 on November 30 in the community of Savoonga, and 1 
bowhead was harvested on November 27 in the community of Gambell. In 
2013, 1 bowhead was harvested on December 4 and 1 on December 6 in 
Savoonga, and no fall whale harvest in Gambell.
    In addition, vessel transit route through the Bering Strait will 
follow a route well east of St. Lawrence Island, placing vessels more 
than 60 miles and 90 miles east of the communities of Savoonga and 
Gambell, respectively. Furthermore, Shell will communicate with all 
communities via its Com Centers as vessels depart the operating area 
and transit into the Bering Sea to ensure that vessel transit does not 
interfere with any hunt.
    Comment 34: The NSB states that it has repeatedly asked that 
industry not enter the Chukchi Sea until after July 15th, which will 
allow for the completion of the beluga whale hunt in Point Lay. The NSB 
states that this will help mitigate some of the impacts to the 
subsistence harvests. The NSB states that it has heard from Shell that 
they do not anticipate arriving until after this date; yet under the 
proposed IHA Shell would be permitted to move into the Chukchi Sea 
beginning on July 1.
    Response: Shell requested take coverage beginning July 1 (Shell 
2015). Upon receiving NSB's comment, NMFS further verified with Shell 
its intended project dates for the exploration drilling program during 
the 2015 Arctic open-water season, and again Shell emphasized that it 
is critical for Shell to enter Chukchi Sea through Bering Strait on or 
after July 1. This timeframe for entry has been an annual component of

[[Page 35755]]

Shell's plans to conduct exploration drilling in the Chukchi Sea since 
2009. To address subsistence impact concerns, Shell developed a robust 
Subsistence Advisor (SA) program within our POC, also adding a 
Communication Plan for direct communication and real-time avoidance of 
impacts to subsistence users and marine mammals. This is specifically 
detailed on page 12-2 of Shell's IHA application. The SA program and 
Communication Plan within that program have been in place since 2009 
and remain due to the proven capability of avoiding impacts to 
subsistence harvests regardless of the location or timing of those 
harvests in the Chukchi and Beaufort Seas. Again in 2015, Shell will 
have SAs and Community Liaisons in place and Communication Centers (Com 
Centers) active along the coasts of the Bering and Chukchi Seas, to 
carry out the POC.
    Shell's general marine vessel route is approximately 54 nautical 
miles offshore of Pt. Lay. Vessels transiting offshore of Point Lay 
will generally be far outside of areas traditionally used by Pt. Lay 
residents for beluga whale subsistence hunting. Therefore, Shell's 
vessels will be positioned well offshore and it is highly unlikely that 
routine vessel transits will impede subsistence users' access to beluga 
whales or cause them to divert from their normal migratory route.
    Finally, Shell is required implement a number of mitigation 
measures to minimize any potential adverse impacts on subsistence 
users. These include the use of Subsistence Advisors, Community Liaison 
Officers, and Com Centers, which will be established and utilized on a 
daily basis to coordinate and modify vessel traffic based on current or 
anticipated subsistence activities. Thus, given the distance of vessel 
traffic in relation to subsistence hunting activities, and with the 
implementation of appropriate mitigation measures, NMFS does not 
believe Shell's entering of the Chukchi Sea prior to July 15 will 
adversely affect beluga whale harvest in Point Lay.
    Comment 35: The NSB requests NMFS require Shell to coordinate with 
the AEWC and other Alaska Native marine mammal user groups as 
appropriate, and participate in the well-established and effective 
Conflict Avoidance Agreement (CAA) process.
    Response: Throughout the incidental take authorization processing 
for the 2015 Arctic open-water industry activities, NMFS has been 
working with stakeholders including the AEWC and other Alaska Native 
marine mammal user groups as appropriate to conduct its analysis on the 
potential impacts of the drilling program on subsistence activities. A 
peer-review meeting on industry's monitoring plans was held in early 
March 2015 in Anchorage, and NMFS invited a representative from the 
AEWC to observe the peer-review process.
    Shell signed the 2015 CAA with the AEWC on April 23, 2015. The CAA 
is a document that is negotiated between and signed by the industry 
participant and subsistence user groups such as 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 marine mammal 
subsistence impacts, the signing of a CAA is not a requirement. NMFS' 
MMPA implementing regulations 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 Plan of Cooperation (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.
    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' IHA includes 
measures from the 2015 CAA between Shell and the AEWC that we believe 
are relevant to ensuring no unmitigable adverse impact on the 
availability of marine mammals for subsistence uses.

Miscellaneous

    Comment 36: Shell points out that the 180 dB re 1 [mu]Pa rms radius 
for zero-offset vertical seismic profile (ZVSP) should be 1.38 km, not 
1.28 km as stated on page 11773 of the Federal Register notice for the 
proposed IHA (80 FR 11726; March 4, 2015).
    Response: NMFS recognizes that this is a typographic error and made 
the correction. This error does not affect the results of the analysis 
since the analysis was conducted on the correct radius of 1.38 km. NMFS 
has corrected the error in the IHA issued to Shell.
    Comment 37: The NSB requests NMFS require Shell to use the best 
available technologies and best management practices for both seismic 
and exploratory drilling, including zero discharge.
    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 38: Several private citizens are concerned about potential 
oil spill from Shell's exploration drilling program in the Chukchi Sea.
    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 (80 
FR 11726; March 4, 2015). NMFS' EA also contains an analysis of the 
potential effects of an oil spill on marine

[[Page 35756]]

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.''
    The Bureau of Ocean Energy Management (BOEM) and the Bureau of 
Safety and Environmental Enforcement (BESS) under the Department of the 
Interior (DOI) are the agencies with expertise in assessing risks of an 
oil spill. In reviewing Shell's Chukchi Sea Exploration Plan and 
Regional Oil Spill Response Plan (OSRP), BOEM and BSEE determined that 
the risk was low and that Shell will implement adequate measures to 
further 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, in 2012 NOAA's Office of Response and Restoration 
reviewed Shell's OSRP and provided input to DOI requesting changes 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's 
Office of Response and Restoration determined that Shell's plans to 
respond to an offshore oil spill in the U.S. Arctic Ocean are 
satisfactory, as stated in a 2012 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.

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 
Endangered Species Act (ESA) and as depleted under the MMPA. The ringed 
seal is listed as ``threatened'' under the ESA. 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 proposed 
activity area. Both the walrus and the polar bear are managed by the 
U.S. Fish and Wildlife Service (USFWS) and are not considered further 
in this IHA notice.
    Of these species, 12 are expected to occur in the area of Shell's 
proposed operations. These species are: 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 likely to be encountered most widely 
(in space and time) throughout the period of the proposed drilling 
program is the ringed seal. Encounters with bowhead and gray whales are 
expected to be limited to particular seasons, as discussed later in 
this document. 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. The explanation for 
those derivations and the actual density estimates are described later 
in this document (see the ``Estimated Take by Incidental Harassment'' 
section).
    The narwhal occurs in Canadian waters and occasionally in the 
Alaskan Beaufort Sea and the Chukchi Sea, but it is considered 
extralimital in U.S. waters and is not expected to be encountered. 
There are scattered records of narwhal in Alaskan waters, including 
reports by subsistence hunters, where the species is considered 
extralimital (Reeves et al., 2002). Due to the rarity of this species 
in the proposed project area and the remote chance it would be affected 
by Shell's proposed Chukchi Sea drilling activities, this species is 
not discussed further in this IHA notice.
    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. 
NMFS consideration of this application later took into account updated 
information on bowhead and beluga whale densities. See ``Estimated Take 
by Incidental Harassment'' section later in this notice. Additional 
information can also be found in the NMFS Stock Assessment Reports 
(SAR). The Alaska 2013 SAR is available at: https://www.nmfs.noaa.gov/pr/sars/pdf/ak2013_final.pdf.
    Table 1 lists the 12 marine mammal species or stocks under NMFS 
jurisdiction with confirmed or possible occurrence in the proposed 
project area.

                Table 1--Marine Mammal Species and Stocks With Confirmed or Possible Occurrence in the Proposed Exploration Drilling Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
           Common name              Scientific name           Status             Occurrence          Seasonality             Range           Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontocetes:
Beluga whale (Eastern Chukchi     Dephinapterus        ...................  Common.............  Mostly spring and    Russia to Canada..           3,710
 Sea stock).                       leucas.                                                        fall with some in
                                                                                                  summer.
Beluga whale (Beaufort Sea        Delphinapterus       ...................  Common.............  Mostly spring and    Russia to Canada..          39,258
 stock).                           leucas.                                                        fall with some in
                                                                                                  summer.
Killer whale....................  Orcinus orca.......  ...................  Occasional/          Mostly summer and    California to                2,084
                                                                             Extralimital.        early fall.          Alaska.
Harbor porpoise.................  Phocoena phocoena..  ...................  Occasional/          Mostly summer and    California to               48,215
                                                                             Extralimital.        early fall.          Alaska.
Mysticetes:
Bowhead whale...................  Balaena mysticetus.  Endangered;          Common.............  Mostly spring and    Russia to Canada..          19,534
                                                        Depleted.                                 fall with some in
                                                                                                  summer.

[[Page 35757]]

 
Gray whale......................  Eschrichtius         ...................  Somewhat common....  Mostly summer......  Mexico to the U.S.          19,126
                                   robustus.                                                                           Arctic Ocean.
Minke whale.....................  Balaenoptera         ...................  Rare...............  Summer.............  North Pacific.....       810-1,003
                                   acutorostrata.
Fin whale (North Pacific stock).  B. physalus........  Endangered;          Rare...............  Summer.............  North Pacific.....           1,652
                                                        Depleted.
Humpback whale (Central North     Megaptera            Endangered;          Rare...............  Summer.............  Central to North            20,800
 Pacific stock).                   novaeangliae.        Depleted.                                                      Pacific.
Pinnipeds:
Bearded seal (Beringia distinct   Erigathus barbatus.  Candidate..........  Common.............  Spring and summer..  Bering, Chukchi,           155,000
 population segment).                                                                                                  and Beaufort Seas.
Ringed seal (Arctic stock)......  Phoca hispida......  Threatened;          Common.............  Year round.........  Bering, Chukchi,           300,000
                                                        Depleted.                                                      and Beaufort Seas.
Spotted seal....................  Phoca largha.......  ...................  Common.............  Summer.............  Japan to U.S.              141,479
                                                                                                                       Arctic Ocean.
Ribbon seal.....................  Histriophoca         Species of concern.  Occasional.........  Summer.............  Russia to U.S.              49,000
                                   fasciata.                                                                           Arctic Ocean.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Potential Effects of the Specified Activity on Marine Mammals

    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). The 
proposed IHA contains a full discussion of the potential impacts to 
marine mammal species in the project area. No changes have been made to 
that discussion, exception a clarification made on marine mammal 
functional hearing groups, which is discussed in Response to Comment 4 
above. Please refer to the proposed IHA for the full discussion of 
potential impacts to marine mammal (80 FR 11726, March 4, 2015). NMFS 
has determined that Shell's exploratory drilling program would only 
result in Level B behavioral harassment of marine mammals, and will not 
cause hearing threshold shifts, injury, and/or mortality to marine 
mammals exposed to noise generated from Shell's activities.

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 (80 
FR 11726, March 4, 2015). 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 
section 101(a)(5)(D) of the MMPA, NMFS must, where applicable, set 
forth the permissible methods of taking pursuant to such activity, and 
other means of effecting the least practicable impact on such species 
or stock and its habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of such species or stock for taking for certain 
subsistence uses (where relevant). This section summarizes the 
mitigation measures Shell is required to implement under the IHA. In 
summary, the following changes have been made to the mitigation since 
the proposed IHA was published: Requiring ramp-up procedure if ZVSP 
airgun has been discontinued for a period of 10 minutes or more, and 
when utilizing the mitigation airgun for position change, use a reduced 
duty cycle (approximately 1 shot per 5 minutes).

Vessel Based Marine Mammal Monitoring for Mitigation (and Other 
Purposes)

    The objectives of the vessel based marine mammal monitoring are to 
ensure that disturbance to marine mammals and subsistence hunts is 
minimized, that effects on marine mammals are documented, and that data 
is collected on the occurrence and distribution of marine mammals in 
the project area.
    The marine mammal monitoring will be implemented by a team of 
protected species observers (PSOs). The PSOs will be biologists and 
Alaska Native personnel trained as field observers. PSOs will be 
stationed on both drilling units, ice management vessels, anchor 
handlers and other drilling support vessels engaged in transit to and 
between drill sites to monitor for marine mammals. The duties of the 
PSOs will include: Watching for and identifying marine mammals, 
recording their numbers, recording distances and reactions of marine 
mammals to exploration drilling activities, initiating mitigation 
measures when appropriate, and reporting results of the vessel based 
monitoring program, which will include the estimation of the number of 
marine mammal ``exposures'' as defined by the NMFS and stipulated in 
the IHA.
    The vessel based work will provide:
     The basis for initiating real-time mitigation, if 
necessary, as required by the various permits that Shell receives;
     Information needed to estimate the number of ``exposures'' 
of marine mammals to sound levels that may

[[Page 35758]]

result in harassment, which must be reported to NMFS;
     Data on the occurrence, distribution, and activities of 
marine mammals in the areas where drilling activity is conducted;
     Information to compare the distances, distributions, 
behavior, and movements of marine mammals relative to the drilling unit 
during times with and without drilling activity occurring;
     A communication channel to coastal communities including 
whalers; and
     Employment and capacity building for local residents, with 
one objective being to develop a larger pool of experienced Alaska 
Native PSOs.
    The vessel based monitoring will be operated and administered 
consistent with monitoring programs conducted during past exploration 
drilling activities, seismic and shallow hazards surveys, or 
alternative requirements stipulated in permits issued to Shell. 
Agreements between Shell and other agencies will also be fully 
incorporated. PSOs will be provided training through a program approved 
by the NMFS.

Mitigation Measures During the Exploration Drilling Program

    Shell's planned exploration drilling activities incorporate design 
features and operational procedures aimed at minimizing potential 
impacts on marine mammals and subsistence hunts. Some of the mitigation 
design features include:
     Conducting pre-season acoustic modeling to establish the 
appropriate exclusion and disturbance zones;
     Vessel based PSO monitoring to implement appropriate 
mitigation if necessary, and to determine the effects of the drilling 
program on marine mammals;
     Passive acoustic monitoring of drilling and vessel sounds 
and marine mammal vocalizations; and
     Aerial surveys with photographic equipment over operations 
and in coastal and nearshore waters with photographic equipment to help 
determine the effects of project activities on marine mammals; and 
seismic activity mitigation measures during acquisition of the ZVSP 
surveys.
    The potential impacts on marine mammals during drilling activities 
will be mitigated through the implementation of several vessel based 
mitigation measures as necessary.
(1) Exclusion and Disturbance Zones
    Mitigation for NMFS' incidental take authorizations typically 
includes ``safety radii'' or ``exclusion zones'' for marine mammals 
around airgun arrays and other impulsive industrial sound sources where 
received levels are >=180 dB re 1 [mu]Pa (rms) for cetaceans and >=190 
dB re 1 [mu]Pa (rms) for pinnipeds. These zones are based on a 
cautionary assumption that sound energy at lower received levels will 
not injure these animals or impair their hearing abilities, but that 
higher received levels might have some such effects. Disturbance or 
behavioral effects to marine mammals from underwater sound may occur 
from exposure to sound at distances greater than these zones 
(Richardson et al. 1995). The NMFS assumes that marine mammals exposed 
to pulsed airgun sounds with received levels >=160 dB re 1 [mu]Pa (rms) 
or continuous sounds from vessel activities with received levels >=120 
dB re 1 [mu]Pa (rms) have the potential to be disturbed. These sound 
level thresholds are currently used by NMFS to define acoustic 
disturbance (harassment) criteria.
(A) Exploration Drilling Activities
    The areas exposed to sounds produced by the drilling units 
Discoverer and Polar Pioneer were determined by measurements from 
drilling in 2012 or were modeled by JASCO Applied Sciences. The 2012 
measurement of the distance to the 120 dB (rms) threshold for normal 
drilling activity by the Discoverer was 0.93 mi (1.5 km) while the 
distance of the >=120 dB (rms) radius during MLC construction was 5.1 
mi (8.2 km).
    Measured sound levels for the Polar Pioneer were not available. Its 
sound footprint was estimated with JASCOs Marine Operations Noise Model 
(MONM) using an average source level derived from a number of reported 
acoustic measurements of comparable semi-submersible drill units, 
including the Ocean Bounty (Gales, 1982), SEDCO 708 (Greene, 1986), and 
Ocean General (McCauley, 1998). The model yielded a propagation range 
of 0.22 mi (0.35 km) for rms sound pressure levels of 120 dB for the 
Polar Pioneer while drilling at the Burger Prospect.
    In addition to drilling and MLC construction, numerous activities 
in support of exploration drilling produce continuous sounds above 120 
dB (rms). These activities in direct support of the moored drilling 
units include ice management, anchor handling, and supply/discharge 
sampling vessels using DP thrusters. Detailed sound characterizations 
for each of these activities are presented in the 2012 Comprehensive 
Report for NMFS' 2012 IHA (LGL et al. 2013).
    The source levels for exploration drilling and related support 
activities are not high enough to cause temporary reduction in hearing 
sensitivity or permanent hearing damage to marine mammals. 
Consequently, mitigation as described for seismic activities. including 
ramp ups, power downs, and shut downs, are not required for exploration 
drilling activities. However, Shell will use PSOs onboard the drilling 
units, ice management, and anchor handling vessels to monitor marine 
mammals and their responses to industry activities, in addition to 
initiating mitigation measures should in-field measurements of the 
activities indicate conditions that may present a risk of unanticipated 
impacts on marine mammals.
(B) ZVSP Surveys
    Two sound sources have been proposed by Shell for the ZVSP surveys. 
The first is a small airgun array that consists of three 150 in\3\ 
(2,458 cu cm3) airguns for a total volume of 450 in\3\ (7,374 cm\3\). 
The second ZVSP sound source consists of two 250 in\3\ (4,097 cm\3\) 
airguns with a total volume of 500 in\3\ (8,194 cm\3\). Sound 
footprints of the ZVSP airgun array configurations were estimated using 
JASCO Applied Sciences' Marine Operations Noise Model (MONM). The model 
results were maximized over all water depths between 9.9 and 23 ft (3 
and 7 m) to yield sound level isopleths as a function of range and 
direction from the source. The 450 in\3\ airgun array at a source depth 
of 23 ft (7 m) yielded the maximum ranges to the >=190, >=180, and 
>=160 dB (rms) isopleths. The estimated 95th percentile distances to 
these thresholds were: 190 dB = 558 ft (170 m), 180 dB = 3,018 ft (920 
m), and 160 dB = 39,239 ft (11,960 m). These distances were multiplied 
by 1.5 as a conservative measure, and the resulting radii are shown in 
Table 2.
    PSOs on the drilling units will initially use the radii in Table 2 
for monitoring and mitigation purposes during ZVSP surveys. An 
acoustics contractor will perform direct measurements of the received 
levels of underwater sound versus distance and direction from the ZVSP 
array using calibrated hydrophones. The mitigation measures to be 
implemented will include pre-ramp up watches, ramp ups, power downs and 
shut downs as described below.

[[Page 35759]]



    Table 2--Estimated Distances of the >=190, 180, and 160, dB (rms)
 Isopleths To Be Used for Mitigation Purposes During ZVSP Surveys Until
                        SSV Results are Available
------------------------------------------------------------------------
                                                             Estimated
        Threshold levels in dB re 1 [mu]Pa (rms)           distance (m)
------------------------------------------------------------------------
>=190...................................................             255
>=180...................................................           1,380
>=160...................................................          11,960
------------------------------------------------------------------------

(2) Ramp Ups
    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of airguns firing until the full volume is achieved. The purpose 
of a ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds 
in the vicinity of the airguns and to provide time for them to leave 
the area, thus avoiding any potential injury or impairment of their 
hearing abilities from higher levels of exposure.
    Shell contact NMFS and clarified the operations of ZVSP uses and 
stated that during the proposed ZVSP surveys, the operator 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 
observation of the exclusion zone by PSOs for a minimum of 30 minutes 
to ensure that no marine mammals are present. The entire exclusion 
zones must be visible during the 30 minutes leading into to a full ramp 
up. If the entire exclusion zone is not visible, a ramp up from a cold 
start cannot begin. If a marine mammal is sighted within the relevant 
exclusion zone during the 30 minutes prior to ramp up, ramp up will be 
delayed until the marine mammal is sighted outside of the exclusion 
zone or is not sighted for at least 15-30 minutes: 15 minutes for small 
odontocetes and pinnipeds, or 30 minutes for baleen whales and large 
odontocetes.
    In addition, if for any reason, use of the airgun array has been 
discontinued for a period of 10 minutes or more, ramp-up procedures 
shall be implemented. Only if the PSO watch has been suspended, a 30-
minute clearance of the exclusion zone is required prior to commencing 
ramp-up. Discontinuation of airgun activity for less than 10 minutes 
does not require a ramp-up; and
    Further, when utilizing the mitigation airgun during position/depth 
change, use a reduced duty cycle (approximately 1 shot every 5 
minutes).
 (3) Power Downs and Shut Downs
    A power down is the immediate reduction in the number of operating 
energy sources from all firing to some smaller number. A shut down 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 shut down 
(i.e., no sources firing).
    After a complete shutdown of the airgun due to detection of a 
marine mammal in the vicinity, airguns cannot be restarted until the 
marine mammal is visually sighted leaving the exclusion zone, or is not 
sighted for at least 15-30 minutes: 15 minutes for small odontocetes 
and pinnipeds, or 30 minutes for baleen whales and large odontocetes.
 (4) Loss of Electrical Power to Airgun Array
    If, for any reason, electrical power to the airgun array has been 
discontinued for a period of 10 minutes or more, ramp-up procedures 
shall be implemented. If the PSO watch has been suspended, a 30-minute 
clearance of the exclusion zone is required prior to commencing ramp-
up. Discontinuation of airgun activity for less than 10 minutes does 
not require a ramp-up.

Mitigation Conclusions

    NMFS has carefully evaluated the applicant's 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.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of noises generated from exploration drilling and associated 
activities, or other activities expected to result in the take of 
marine mammals (this goal may contribute to 1, above, or to reducing 
harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of noises generated from exploration drilling and 
associated activities, or other activities expected to result in the 
take of marine mammals (this goal may contribute to 1, above, or to 
reducing harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of noises generated from exploration drilling and associated 
activities, or other activities expected to result in the take of 
marine mammals (this goal may contribute to a, above, or to reducing 
the severity of harassment takes only).
    5. Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    6. For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of the applicant's mitigation measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
prescribed mitigation measures provide the means of effecting the least 
practicable impact on marine mammals species or stocks and their 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance. Mitigation to effect least practicable 
impact on the availability of marine mammals for taking for subsistence 
uses is discussed later in this document (see ``Impact on Availability 
of Affected Species or Stock

[[Page 35760]]

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. The change made from the proposed notice 
for the IHA is that Shell revised the deployment design of its acoustic 
arrays for passive acoustic monitoring based on recommendations from 
the peer-review panel. This is discussed in detail in the ``Monitoring 
Plan Peer Review'' section below.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    1. An increase in the probability of detecting marine mammals, both 
within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    2. An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of noises generated from exploration 
drilling and associated activities that we associate with specific 
adverse effects, such as behavioral harassment, TTS, or PTS;
    3. An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how anticipated adverse 
effects on individuals (in different ways and to varying degrees) may 
impact the population, species, or stock (specifically through effects 
on annual rates of recruitment or survival) through any of the 
following methods:
    [ssquf] Behavioral observations in the presence of stimuli compared 
to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
    [ssquf] Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
    [ssquf] Distribution and/or abundance comparisons in times or areas 
with concentrated stimuli versus times or areas without stimuli;
    4. An increased knowledge of the affected species; and
    5. An increase in our understanding of the effectiveness of certain 
mitigation and monitoring measures.
    NMFS believes that the required measures will contribute towards 
these goals.

Monitoring Measures

1. Protected Species Observers
    Vessel based monitoring for marine mammals will be done by trained 
PSOs on both drilling units and ice management and anchor handler 
vessels throughout the exploration drilling activities. The observers 
will monitor the occurrence and behavior of marine mammals near the 
drilling units, ice management and anchor handling vessels, during all 
daylight periods during the exploration drilling operation, and during 
most periods when exploration drilling is not being conducted. PSO 
duties will include watching for and identifying marine mammals; 
recording their numbers, distances, and reactions to the exploration 
drilling activities; and documenting exposures to sound levels that may 
constitute harassment. PSOs also will help ensure that the vessel 
communicates with the Communications and Call Centers (Com Centers) in 
Native villages along the Chukchi Sea coast.
(A) Number of Observers
    A sufficient number of PSOs will be onboard to meet the following 
criteria:
     100 percent monitoring coverage during all periods of 
exploration drilling operations in daylight;
     Maximum of four consecutive hours on watch per PSO; and
     Maximum of approximately 12 hours on watch per day per 
PSO.
    PSO teams will consist of trained Alaska Natives and field 
biologist observers. An experienced field crew leader will be on every 
PSO team aboard the drilling units, ice management and anchor handling 
vessels, and other support vessels during the exploration drilling 
program. The total number of PSOs aboard may decrease later in the 
season as the duration of daylight decreases.
(B) Crew Rotation
    Shell anticipates that there will be provisions for crew rotation 
at least every three to six weeks to avoid observer fatigue. During 
crew rotations detailed notes will be provided to the incoming crew 
leader. Other communications such as email, fax, and/or phone 
communication between the current and oncoming crew leaders during each 
rotation will also occur when necessary. In the event of an unexpected 
crew change Shell will facilitate such communications to insure 
monitoring consistency among shifts.
(C) Observer Qualifications and Training
    Crew leaders serving as PSOs will have experience from one or more 
projects with operators in Alaska or the Canadian Beaufort.
    Crew leaders will be highly experienced with previous vessel based 
marine mammal monitoring projects. Resumes for those individuals will 
be provided to the NMFS for approval. All PSOs will be trained and 
familiar with the marine mammals of the area. A PSO handbook, adapted 
for the specifics of the planned Shell drilling program, will be 
prepared and distributed beforehand to all PSOs.
    PSOs will also complete a two-day training and refresher session on 
marine mammal monitoring, to be conducted shortly before the 
anticipated start of the drilling season. The training sessions will be 
conducted by marine mammalogists with extensive crew leader experience 
from previous vessel based seismic monitoring programs in the Arctic.
    Primary objectives of the training include:
     Review of the 4MP for this project, including any 
amendments adopted or specified by NMFS in the final IHA or other 
agreements in which Shell may elect to participate;
     Review of marine mammal sighting, identification, 
(photographs and videos) and distance estimation methods, including any 
amendments specified by NMFS in the IHA;
     Review operation of specialized equipment (e.g., reticle 
binoculars, big eye binoculars, night vision devices, GPS system); and
     Review of data recording and data entry systems, including 
procedures for recording data on mammal sightings, exploration drilling 
and monitoring activities, environmental conditions, and entry error 
control. These procedures will be implemented through use of a 
customized computer databases and laptop computers.
(D) PSO Handbook
    A PSO Handbook will be prepared for Shell's monitoring program. The 
Handbook will contain maps, illustrations, and photographs as well as 
copies of important documents and

[[Page 35761]]

descriptive text and are intended to provide guidance and reference 
information to trained individuals who will participate as PSOs. The 
following topics will be covered in the PSO Handbook:
     Summary overview descriptions of the project, marine 
mammals and underwater sound energy, the 4MP (vessel-based, aerial, 
acoustic measurements, special studies), the IHA and other regulations/
permits/agencies, the Marine Mammal Protection Act;
     Monitoring and mitigation objectives and procedures, 
including initial exclusion and disturbance zones;
     Responsibilities of staff and crew regarding the 4MP;
     Instructions for staff and crew regarding the 4MP;
     Data recording procedures: Codes and coding instructions, 
common coding mistakes, electronic database; navigational, marine 
physical, and drilling data recording, field data sheet;
     Use of specialized field equipment (e.g., reticle 
binoculars, Big-eye binoculars, NVDs, laser rangefinders);
     Reticle binocular distance scale;
     Table of wind speed, Beaufort wind force, and sea state 
codes;
     Data storage and backup procedures;
     List of species that might be encountered: Identification, 
natural history;
     Safety precautions while onboard;
     Crew and/or personnel discord; conflict resolution among 
PSOs and crew;
     Drug and alcohol policy and testing;
     Scheduling of cruises and watches;
     Communications;
     List of field gear provided;
     Suggested list of personal items to pack;
     Suggested literature, or literature cited;
     Field reporting requirements and procedures;
     Copies of the IHA will be made available; and
     Areas where vessels need permission to operate such as the 
Ledyard Bay Critical Habitat Unit (LBCHU).
2. Vessel-Based Monitoring Methodology
    The observer(s) will watch for marine mammals from the best 
available vantage point on the drilling units and support vessels 30 
minutes before and during Shell's activities, and for 30 minutes after 
the activities are ceased. Ideally this vantage point is an elevated 
stable platform from which the PSO has an unobstructed 360[deg] view of 
the water. The observer(s) will scan systematically with the naked eye 
and 7 x 50 reticle binoculars, supplemented with Big-eye binoculars and 
night-vision equipment when needed. Personnel on the bridge will assist 
the marine mammal observer(s) in watching for pinnipeds and cetaceans. 
New or inexperienced PSOs will be paired with an experienced PSO or 
experienced field biologist so that the quality of marine mammal 
observations and data recording is kept consistent.
    Information to be recorded by marine mammal observers will include 
the same types of information that were recorded during previous 
monitoring projects (e.g., Moulton and Lawson 2002; Reiser et al. 2010, 
2011; Bisson et al. 2013). When a mammal sighting is made, the 
following information about the sighting will be carefully and 
accurately recorded:
     Species, group size, age/size/sex categories (if 
determinable), physical description of features that were observed or 
determined not to be present in the case of unknown or unidentified 
animals;
     Behavior when first sighted and after initial sighting;
     Heading (if consistent), bearing and distance from 
observer;
     Apparent reaction to activities (e.g., none, avoidance, 
approach, paralleling, etc.), closest point of approach, and behavioral 
pace;
     Time, location, speed, and activity of the vessel, sea 
state, ice cover, visibility, and sun glare, on support vessels the 
distance and bearing to the drilling unit will also be recorded; and
     Positions of other vessel(s) in the vicinity of the 
observer location.
    The vessel's position, speed, water depth, sea state, ice cover, 
visibility, and sun glare will also be recorded at the start and end of 
each observation watch, every 30 minutes during a watch, and whenever 
there is a change in any of those variables.
    Distances to nearby marine mammals will be estimated with 
binoculars (Fujinon 7 x 50 binoculars) containing a reticle to measure 
the vertical angle of the line of sight to the animal relative to the 
horizon.
    An electronic database will be used to record and collate data 
obtained from visual observations during the vessel-based study. The 
PSOs will enter the data into the custom data entry program installed 
on field laptops. The data entry program automates the data entry 
process and reduces data entry errors and maximizes PSO time spent 
looking at the water. PSOs also have voice recorders available to them. 
This is another tool that will allow PSOs to maximize time spent 
focused on the water.
    PSOs will be instructed to identify animals as unknown when 
appropriate rather than strive to identify an animal when there is 
significant uncertainty. PSOs should also 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 will also be placed on recording what was not seen, such as 
dorsal features.
(A) Monitoring at Night and in Poor Visibility
    Night-vision equipment ``Generation 3'' binocular image 
intensifiers or equivalent units will be available for use when needed. 
However, past experience with night-vision devices in the Beaufort Sea 
and elsewhere indicates they are not nearly as effective as visual 
observation during daylight hours (e.g., Harris et al. 1997, 1998; 
Moulton and Lawson 2002; Hartin et al. 2013).
(B) Specialized Field Equipment
    Shell will provide the following specialized field equipment for 
use by the onboard PSOs: Reticle binoculars, Big-eye binoculars, GPS 
unit, laptop computers, night vision binoculars, and possibly digital 
still and digital video cameras. Big eye binoculars will be mounted and 
used on key monitoring vessels including the drilling units, ice 
management vessels and the anchor handler.
(C) Field Data-Recording, Verification, Handling, and Security
    The observers on the drilling units and support vessels will record 
their observations directly into computers using a custom software 
package. The accuracy of the data entry will be verified in the field 
by computerized validity checks as the data are entered, and by 
subsequent manual checking. These procedures will allow initial 
summaries of data to be prepared during and shortly after the field 
season, and will facilitate transfer of the data to statistical, 
graphical or other programs for further processing. Quality control of 
the data will be facilitated by (1) the start-of-season training 
session, (2) subsequent supervision by the onboard field crew leader, 
and (3) ongoing data checks during the field season.
    The data will be sent off of the vessel to Anchorage on a daily 
basis and backed up regularly onto storage devices on the vessel, and 
stored at separate locations on the vessel. If practicable, hand-
written data sheets will be photocopied daily during the field

[[Page 35762]]

season. Data will be secured further by having data sheets and backup 
data devices carried back to the Anchorage office during crew 
rotations.
    PSOs will be able to plot sightings in near real-time for their 
vessel. Significant sightings from key vessels including drilling 
units, 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).
    Observer training will emphasize the use of ``comments'' for 
sightings that may be considered unique or not fully captured by 
standard data codes. In addition to the standard marine mammal 
sightings forms, a specialized form was developed for recording 
traditional knowledge and natural history observations. PSOs will be 
encouraged to use this form to capture observations related to any 
aspect of the arctic environment and the marine mammals found within 
it. Examples might include relationships between ice and marine mammal 
sightings, marine mammal behaviors, comparisons of observations among 
different years/seasons, etc. Voice recorders will also be available 
for observers to use during periods when large numbers of animals may 
be present and it is difficult to capture all of the sightings on 
written or digital forms. These recorders can also be used to capture 
traditional knowledge and natural history observations should 
individuals feel more comfortable using the recorders rather than 
writing down their comments. Copies of these records will be available 
to all observers for reference if they wish to prepare a statement 
about their observations for reporting purposes. If prepared, this 
statement would be included in the 90-day and final reports documenting 
the monitoring work.
3. Acoustic Monitoring Plan
Exploration Drilling, ZVSP, and Vessel Noise Measurements
    Exploration 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 drilling units. 
The goals of these measurements are:
     To quantify the absolute sound levels produced by 
exploration drilling and to monitor their variations with time, 
distance and direction from the drilling unit;
     To measure the sound levels produced by vessels while 
operating in direct support of exploration drilling operations. These 
vessels will include crew change vessels, tugs, ice-management vessels, 
and spill response vessels not measured in 2012; and
     To measure the sound levels produced by an end-of-hole 
zero-offset vertical seismic profile (ZVSP) survey using a stationary 
sound source.
    Sound characterization and measurements of all exploration drilling 
activities will be performed using two sets of six parallel Autonomous 
Multichannel Acoustic Recorders (AMAR) deployed on the seabed along the 
distances of 0.5, 1, 2, 4, 8 and 16 mi from each drilling unit. All 12 
recording stations will sample at least at 32 kHz, providing calibrated 
acoustic measurements in the 5 Hz to 16 kHz frequency band. The 
logarithmic spacing of the recorders is designed to sample the 
attenuation of drilling unit sounds with distance, and also provide 
information on potential marine mammal displacement. The autonomous 
recorders will sample through completion of the first well, to provide 
a detailed record of sounds emitted from all activities. These 
recorders will be retrieved and their data analyzed and reported in the 
project's 90-day report.
    The deployment of drilling sound monitoring equipment will occur 
before, or as soon as possible after the Discoverer and the Polar 
Pioneer are on site. Activity logs of exploration drilling operations 
and nearby vessel activities will be maintained to correlate with these 
acoustic measurements. All results, including back-propagated source 
levels for each operation, will be reported in the 90-day report.
(A) Vessel Sound Characterization
    Vessel sound characterizations will be performed using dedicated 
recorders deployed at sufficient distances from exploration drilling 
operations so that sound produced by those activities does not 
interfere. Three AMAR acoustic recorders will be deployed on and 
perpendicular to a sail track on which all Shell contracted vessels 
will transit. 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 and 6 
miles (5 and 10 km) respectively, while broadside and other directions 
are sampled as the vessels pass closer to the recorders.
    Vessel sound measurements will be processed and reported in a 
manner similar to that used by Shell and other operators in the 
Beaufort and Chukchi Seas during seismic survey operations. The 
measurements will further be analyzed to calculate source levels. 
Source directivity effects will be examined and reported. The 
measurements will include sound level data but not source level 
calculations. All vessel characterization results, including source 
levels, will be reported in \1/3\-octave bands in the project 90-day 
report.
(B) Zero-Offset Vertical Seismic Profiling Sound Monitoring
    Shell may conduct ZVSP at two drill sites in 2015. See the Federal 
Register Notice of proposed IHA for information on this activity.
    ZVSP sound verification measurements will be performed using either 
the AMARs that are deployed for drilling unit sound characterizations, 
or by JASCO Ocean Bottom Hydrophone (OBH) recorders. The AMARs will not 
be retrieved until several days after the ZVSP as they are intended to 
monitor during retrievals of drilling unit anchors and related support 
activities.
(C) Acoustic Data Analyses
    Exploration drilling sound data will be analyzed to extract a 
record of the frequency-dependent sound levels as a function of time. 
These results are useful for correlating measured sound energy events 
with specific survey operations. The analysis provides absolute sound 
levels in finite frequency bands that can be tailored to match the 
highest-sensitivity hearing ranges for species of interest. The 
analyses will also consider sound level integrated through 1-hour 
durations (referred to as sound energy equivalent level Leq (1-hour). 
Similar graphs for long time periods will be generated as part of the 
data analysis performed for indicating drilling sound variation with 
time in selected frequency bands.
(D) Reporting of Results
    Acoustic sound level results will be reported in the 90-day and 
comprehensive reports for this program. The results reported will 
include:
     Sound source levels for the drilling units and all 
drilling support vessels;
     Spectrogram and band level versus time plots computed from 
the continuous recordings obtained from the hydrophone systems;
     Hourly Leq levels at the hydrophone locations; and
     Correlation of exploration drilling source levels with the 
type of

[[Page 35763]]

exploration drilling operation being performed. These results will be 
obtained by observing differences in drilling sound associated with 
differences in drilling unit activities as indicated in detailed 
drilling unit logs.
Acoustic ``Net'' Array in Chukchi Sea
    This section describes acoustic studies that were undertaken from 
2006 through 2013 in the Chukchi Sea as part of the Joint Monitoring 
Program and that will be continued by Shell during exploration drilling 
activities. The acoustic ``net'' array used during the 2006-2013 field 
seasons in the Chukchi Sea was designed to accomplish two main 
objectives. The first was to collect information on the occurrence and 
distribution of marine mammals (including beluga whale, bowhead whale, 
and other species) that may be available to subsistence hunters near 
villages along the Chukchi Sea coast and to document their relative 
abundance, habitat use, and migratory patterns. The second objective 
was to measure the ambient soundscape throughout the eastern Chukchi 
Sea and to record received levels of sounds from industry and other 
activities further offshore in the Chukchi Sea.
    A net array configuration similar to that deployed in 2007-2013 is 
again proposed. The basic components of this effort consist of 
autonomous acoustic recorders deployed widely across the U.S. Chukchi 
Sea during the open water season and then more limited arrays during 
the winter season. These calibrated systems sample at 16 kHz with 24-
bit resolution, and are capable of recording marine mammal sounds and 
making anthropogenic noise measurements. The net array configuration 
will include a regional array of 23 AMAR recorders deployed July-
October off the four main transect locations: Cape Lisburne, Point Lay, 
Wainwright and Barrow. All of these offshore systems will capture 
sounds associated with exploration drilling, where present, over large 
distances to help characterize the sound transmission properties in the 
Chukchi Sea. Six additional summer AMAR recorders will be deployed 
around the Burger drill sites to monitor directional variations and 
longer-range propagation of drilling-related sounds. These recorders 
will also be used to examine marine mammal vocalization patterns in the 
vicinity of exploration drilling activities. The regional recorders 
will be retrieved in early October 2015; acoustic monitoring will 
continue through the winter with 8 AMAR recorders deployed October 
2015-August 2016. The winter recorders will sample at 16 kHz on a 17% 
duty cycle (40 minutes every 4 hours). The winter recorders deployed in 
previous years have provided important information about fall and 
spring migrations of bowhead, beluga, walrus and several seal species.
    The Chukchi acoustic net array will produce an extremely large 
dataset comprising several Terabytes of acoustic data. The analyses of 
these data require identification of marine mammal vocalizations. 
Because of the very large amount of data to be processed, the analysis 
methods will incorporate automated vocalization detection algorithms 
that have been developed over several years. While the hydrophones used 
in the net array are not directional, and therefore not capable of 
accurate localization of detections, the number of vocalizations 
detected on each of the sensors provides a measure of the relative 
spatial distribution of some marine mammal species, assuming that 
vocalization patterns are consistent within a species across the 
spatial and geographic distribution of the hydrophone array. These 
results therefore provide information such as timing of migrations and 
routes of migration for belugas and bowheads.
    A second purpose of the Chukchi net array is to monitor the 
amplitude of exploration drilling sound propagation over a very large 
area. It is expected that sounds from exploratory drilling activities 
will be detectable on hydrophone systems within approximately 30 km of 
the drilling units when ambient sound energy conditions are low. The 
drilling sound levels at recorder locations will be quantified and 
reported.
    Analysis of all acoustic data will be prioritized to address the 
primary questions. The primary data analysis questions are to (a) 
determine when, where, and what species of animals are acoustically 
detected on each recorder (b) analyze data as a whole to determine 
offshore distributions as a function of time, (c) quantify spatial and 
temporal variability in the ambient sound energy, and (d) measure 
received levels of exploration drilling survey events and drilling unit 
activities. The detection data will be used to develop spatial and 
temporal animal detection distributions. Statistical analyses will be 
used to test for changes in animal detections and distributions as a 
function of different variables (e.g., time of day, season, 
environmental conditions, ambient sound energy, and drilling or vessel 
sound levels).
4. Chukchi Offshore Aerial Photographic Monitoring Program
    Shell has been reticent to conduct manned aerial surveys in the 
offshore Chukchi Sea because conducting those surveys puts people at 
risk. There is a strong desire, however, to obtain data on marine 
mammal distribution in the offshore Chukchi Sea and Shell will conduct 
a photographic aerial survey that would put fewer people at risk as an 
alternative to the fully-manned aerial survey. The photographic survey 
would reduce the number of people on board the aircraft from six 
persons to two persons (the pilot and copilot) and would serve as a 
pilot study for future surveys that would use an Unmanned Aerial System 
(UAS) to capture the imagery.
    Aerial photographic surveys have been used to monitor distribution 
and estimate densities of marine mammals in offshore areas since the 
mid-1980s, and before that, were used to estimate numbers of animals in 
large concentration areas. Digital photographs provide many advantages 
over observations made by people if the imagery has sufficient 
resolution (Koski et al. 2013). With photographs there is constant 
detectability across the imagery, whereas observations by people 
decline with distance from the center line of the survey area. 
Observations at the outer limits of the transect can decline to 5-10% 
of the animals present for real-time observations by people during an 
aerial survey. The distance from the trackline of sightings is more 
accurately determined from photographs; group size can be more 
accurately determined; and sizes of animals can be measured, and hence 
much more accurately determined, in photographs. As a result of the 
latter capability, the presence or absence of a calf can be more 
accurately determined from a photograph than by in-the-moment visual 
observations. Another benefit of photographs over visual observations 
is that photographs can be reviewed by more than one independent 
observer allowing quantification of detection, identification and group 
size biases.
    The proposed photographic survey will provide imagery that can be 
used to evaluate the ability of future studies to use the same image 
capturing systems in an UAS where people would not be put at risk. 
Although the two platforms are not the same, the slower airspeed and 
potentially lower flight altitude of the UAS would mean that the data 
quality would be better from the UAS. Initial comparisons have been 
made between data collected by human observers on

[[Page 35764]]

board both the Chukchi and Beaufort aerial survey aircraft and the 
digital imagery collected in 2012. Overall, the imagery provided better 
estimates of the number of large cetaceans and pinnipeds present but 
fewer sightings were identified to species in the imagery than by PSOs, 
because the PSOs had sightings in view for a longer period of time and 
could use behavior to differentiate species. The comparisons indicated 
that some cetaceans that were not seen by PSOs were detected in the 
imagery; errors in identification were made by the PSOs during the 
survey that could be resolved from examination of the imagery; 
cetaceans seen by PSOs were visible in the imagery; and during periods 
with large numbers of sightings, the imagery provided much better 
estimates of numbers of sightings and group size than the PSO data.
    Photographic surveys would start as soon as the ice management, 
anchor handler and drilling units are at or near the first drill site 
and would continue throughout the drilling period and until the 
drilling related vessels have left the exploration drilling area. Since 
the current plans are for vessels to enter the Chukchi Sea on or about 
1 July, surveys would be initiated on or about 3 July. This start date 
differs from past practices of beginning five days prior to initiation 
of an activity and continuing until five days after cessation of the 
activity because the presence of vessels with helidecks in the area 
where overflights will occur is one of the main mitigations that will 
allow for safe operation of the overflight program this far offshore. 
The surveys will be based out of Barrow and the same aircraft will 
conduct the offshore surveys around the drilling units and the coastal 
saw-tooth pattern. The surveys of offshore areas around the drilling 
units will take precedence over the sawtooth survey, but if weather 
does not permit surveying offshore, the nearshore survey will be 
conducted if weather permits.
    The aerial survey grids are designed to maximize coverage of the 
sound level fields of the drilling units during the different 
exploratory drilling activities. The survey grids can be modified as 
necessary based on weather and whether a noisy activity or quiet 
activity is taking place. The intensive survey design maximizes the 
effort over the area where sound levels are highest. The outer survey 
grid covers an elliptical area with a 45 km radius near the center of 
the ellipse. The spacing of the outer survey lines is 10 km, and the 
spacing between the intensive and outer lines is 5 km. The expanded 
survey grid covers a larger survey area, and the design is based on an 
elliptical area with a 50 km radius centered on the well sties. For 
both survey designs the main transects will be spaced 10 km apart which 
will allow even coverage of the survey area during a single flight if 
weather conditions permit completion of a survey. A random starting 
point will be selected for each survey and the evenly spaced lines will 
be shifted NE. or SW. along the perimeter of the elliptical survey area 
based on the start point. The total length of survey lines will be 
about 1,000 km and the exact length will depend on the location of the 
randomly selected start point.
    Following each survey, the imagery will be downloaded from the 
memory card to a portable hard drive and then backed up on a second 
hard drive and stored at accommodations in Barrow until the second hard 
drive can be transferred to Anchorage. In Anchorage, the imagery will 
be processed through a computer-assisted analysis program to identify 
where marine mammal sightings might be located among the many images 
obtained. A team of trained photo analysts will review the photographs 
identified as having potential sightings and record the appropriate 
data on each sighting. If time permits, a second review of some of the 
images will be conducted while in the field, but the sightings recorded 
during the second pass will be identified in the database as secondary 
sightings, so that biases associated with the detection in the imagery 
can be quantified. If time does not permit that review to be conducted 
while in the field, the review will be conducted by personnel in the 
office during or after the field season. A sample of images that are 
not identified by the computer-assisted analysis program will be 
examined in detail by the image analysts to determine if the program 
has missed marine mammal sightings. If the analysis program has missed 
mammal sightings, these data will be to develop correction factors to 
account for these missed sightings among the images that were not 
examined.
5. Chukchi Sea Coastal Aerial Survey
    Nearshore aerial surveys of marine mammals in the Chukchi Sea were 
conducted over coastal areas to approximately 23 miles (mi) [37 
kilometers (km)] offshore in 2006-2008 and in 2010 in support of 
Shell's summer seismic exploration activities. In 2012 these surveys 
were flown when it was not possible to fly the photographic transects 
out over the Burger well site due to weather or rescue craft 
availability. These surveys provided data on the distribution and 
abundance of marine mammals in nearshore waters of the Chukchi Sea. 
Shell plans to conduct these nearshore aerial surveys in the Chukchi 
Sea as opportunities unfold and surveys will be similar to those 
conducted during previous years except that no PSOs will be onboard the 
aircraft. As noted above, the first priority will be to conduct 
photographic surveys around the offshore exploration drilling 
activities, but nearshore surveys will be conducted whenever weather 
does not permit flying offshore. As in past years, surveys in the 
southern part of the nearshore survey area will depend on the end of 
the beluga hunt near Point Lay. In past years, Point Lay has requested 
that aerial surveys not be conducted until after the beluga hunt has 
ended and so the start of surveys has been delayed until mid-July.
    Alaskan Natives from villages along the east coast of the Chukchi 
Sea hunt marine mammals during the summer and Native communities are 
concerned that offshore oil and gas exploration activities may 
negatively impact their ability to harvest marine mammals. Of 
particular concern are potential impacts on the beluga harvest at Point 
Lay and on future bowhead harvests at Point Hope, Point Lay, Wainwright 
and Barrow. Other species of concern in the Chukchi Sea include the 
gray whale; bearded, ringed, and spotted seals. Gray whale and harbor 
porpoise are expected to be the most numerous cetacean species 
encountered during the proposed aerial survey; although harbor porpoise 
are abundant they are difficult to detect from aircraft because of 
their small size and brief surfacing. Beluga whales may occur in high 
numbers early in the season. The ringed seal is likely to be the most 
abundant pinniped species. The current aerial survey program will be 
designed to collect distribution data on cetaceans but will be limited 
in its ability to collect similar data on pinnipeds and harbor 
porpoises because they are not reliably detectable during review of the 
collected images unless a third camera with a 50 mm or similar lens is 
deployed.
    Transects will be flown in a saw-toothed pattern between the shore 
and 23 mi (37 km) offshore as well as along the coast from Point Barrow 
to Point Hope. This design will permit completion of the survey in one 
to two days and will provide representative coverage of the nearshore 
region. Sawtooth transects were designed by placing transect start/end 
points every 34 mi (55 km) along the offshore boundary of this 23 mi 
(37 km) wide nearshore zone, and at midpoints between those points 
along the coast. The transect line start/end points will

[[Page 35765]]

be shifted along both the coast and the offshore boundary for each 
survey based upon a randomized starting location, but overall survey 
distance will not vary substantially. The coastline transect will 
simply follow the coastline or barrier islands. As with past surveys of 
the Chukchi Sea coast, coordination with coastal villages to avoid 
disturbance of the beluga whale subsistence hunt will be extremely 
important. ``No-fly'' zones around coastal villages or other hunting 
areas established during communications with village representatives 
will be in place until the end of the hunting season.
    Standard aerial survey procedures used in previous marine mammal 
projects (by Shell as well as by others) will be followed. This will 
facilitate comparisons and (as appropriate) pooling with other data, 
and will minimize controversy about the chosen survey procedures. The 
aircraft will be flown at 110-120 knots ground speed and usually at an 
altitude of 1,000 ft (305 m). Aerial surveys at an altitude of 1,000 ft 
(305 m) do not provide much information about seals but are suitable 
for bowhead, beluga, and gray whales. The need for a 1,000+ ft (305+ m) 
or 1,500+ ft (454+ m) cloud ceiling will limit the dates and times when 
surveys can be flown. Selection of a higher altitude for surveys would 
result in a significant reduction in the number of days during which 
surveys would be possible, impairing the ability of the aerial program 
to meet its objectives.
    The surveyed area will include waters where belugas are usually 
available to subsistence hunters. If large concentrations of belugas 
are encountered during the survey, the aircraft will climb to ~10,000 
ft (3,050 m) altitude to avoid disturbing the cetaceans. If cetaceans 
are in offshore areas, the aircraft will climb high enough to include 
all cetaceans within a single photograph; typically about 3,000 ft (914 
m) altitude. When in shallow water, belugas and other marine mammals 
are more sensitive to aircraft over flights and other forms of 
disturbance than when they are offshore (see Richardson et al. 1995 for 
a review). They frequently leave shallow estuaries when over flown at 
altitudes of 2,000-3,000 ft (610-904 m); whereas they rarely react to 
aircraft at 1,500 ft (457 m) when offshore in deeper water.

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)). 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 established an independent peer review panel to review Shell's 
4MP for the proposed exploration drilling in the Chukchi Sea. The panel 
met in early March 2015, and provided comments and recommendations to 
NMFS in April 2015. The full panel report can be viewed on the Internet 
at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm.
    NMFS provided the panel with Shell's IHA application and monitoring 
plan and asked the panel to answer the following questions:
    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)?
    The peer-review panel report contains recommendations that the 
panel members felt were applicable to the Shell' monitoring plans. The 
panel concluded that the proposed exclusion zones, PSO vessel-based and 
aerial effort described in the 4MP will further the understanding of 
the impacts of the activities on marine mammals. However, the panel 
also pointed out that Shell's passive acoustics monitoring objectives 
did not include monitoring for negative effects of drilling activities 
such as spatial displacement. In addition, the panel concluded that the 
methodology described in the 4MP would only cover the stated objectives 
during good visibility day-light operations, where visual effort is 
most efficient. To compensate for these issues, the panel recommended 
Shell modify the deployment configuration of passive acoustic sensors 
to allow proper evaluation of evaluating the potential for spatial 
displacement of marine mammals. The panel provided two options:
    Option A: Involves 4 axial deployment lines to independently 
evaluate effects of each drilling site; and
    Option B: Involves 3 axial deployment lines but reduces the 
capacity to tease effects from each drilling site.
    In addition, the panel recommended that the aerial survey transect 
lines be oriented parallel to the acoustic arrays and/or the axis 
between the two drill sites for compatibility with acoustic data.
    Furthermore, the panel also provided comments on reporting measures 
and requests that the 90-day monitoring report include sightability 
curves for each species observed in the study area, and to report 
concurrent collection of spatially overlapped visual and acoustic data 
to allow for a more detailed description of approximate acoustic 
detection ranges for the different species sighted and acoustically 
detected.
    NMFS discussed these recommendations with Shell to improve its 
monitoring and reporting measures. As a result, Shell considered 
localizing arrays of the types proposed by the peer review panel when 
designing its original passive acoustic monitoring plan. That analysis 
generated predicted detection ranges for marine mammal calls in the 
presence of support vessel and drilling activity sounds. It was found 
that detection ranges would be small (often less than 2 km) in the 
presence of the expected sound levels within a few kilometers of the 
drill sites. The panel's suggested recorder spacing is 5 km, so the 
effectiveness of the array would be limited. The layout of recorders 
close to the drilling sites as originally proposed was designed to 
focus on quantifying drilling source levels and ZVSP sound levels as a 
function of distance away from the drill sites.
    Even though its localizing abilities might be limited, especially 
with respect to being able to examine deflections, the approximate 
geometry of part of the Panel's Option A can be achieved by simply 
reorienting Shell's drill rig sound characterization arrays. Shell 
therefore modified the initial layout to approximate the panel's Option 
A array layout.

[[Page 35766]]

    For recommendations concerning reporting measures, Shell agrees to 
provide:
    (1) Sightability curves by species or species group in the 90-day 
report, as appropriate given the data collected, and
    (2) Visual and acoustic detection results overlaid in the 90-day 
report to the extent allowed by data collected in 2015.
    Concerning the comment on orienting aerial transect lines parallel 
to the acoustic arrays and/or the axis between the two drill sites for 
compatibility with acoustic data, Shell determined that a north-south 
orientation that would be perpendicular to the generally east-west 
migration of bowheads may be advantageous to generating statistically 
robust density estimates. The original northwest-southeast orientation 
was designed to be consistent with the ASAMM survey lines that cover 
the greater region.
    Since the Burger aerial survey does not tie-back to the coastline, 
maintaining consistency with the ASAMM survey lines is less useful than 
orienting the lines to be perpendicular with the migration of bowheads. 
Therefore, Shell is considering shifting the orientation of the survey 
lines to be north-south. However, for safety reasons, further analysis 
of the overall flight time and duration of time spent on the western 
edge of the survey area using the north-south survey lines must be 
completed before the orientation and location of the lines can be 
finalized. Shell states that it must assess the specifics of flight 
times, aviation fuel requirements, and distances for which search and 
rescue (SAR) coverage exists, among other factors before committing to 
a change in the flight pattern and flight duration. If flight pattern 
changes as described above meet the Shell safety standards, Shell may 
be able to alter the flight patterns in time for the 2015 season. Shell 
will not alter the map of the proposed route map in the 4MP, but would 
reflect the change in the resulting 90-day report following the season 
should changes be made to the flight patterns flown. NMFS is satisfied 
with this explanation and approach to making the recommended change, 
and did not incorporate the recommendation from the panel regarding 
flight pattern changes.
    Additionally, though not requested, the peer review panel also 
recommended a number of mitigation measures listed below:
    (1) If a bowhead whale or other large whale has been sighted within 
2,000 m of the drilling site during the 5 days prior to the onset of 
ZVSP operations, airgun activity should be avoided outside good 
visibility day-light periods.
    (2) Implement power-down or shutdown procedures if a bowhead whale 
mother/calf pair or an aggregation of 3 or more bowhead or gray whales 
is sighted within 2,000 m of the airgun array.
    (3) Mitigation gun cannot be used for more than 30 min during 
repositioning, and then Shell should initiate standard ramp-up 
procedures prior to the use of the full airgun array.
    (4) Vessels maintain quiet when stationary, i.e, vessels be 
anchored with engines and depth sounder off (as appropriate from a 
safety point of view), preferably near an acoustic mooring to allow 
PSOs to scan for marine mammals.
    NMFS analyzed these recommendations and worked with Shell to 
understand the practicability of these mitigation recommendations and 
concluded that these measures either do not provide added value to the 
existing mitigation measures already prescribed and/or are 
impracticable due to costs for the company for the following reasons:
    (1) 2,000 meter exclusion zone--Shell has already incorporated a 
50% safety margin into the proposed 1,380 m exclusion zone for ZVSP. 
Thus, the established safety zone is already conservative. Moreover, 
PSO monitoring will be more effective over this radius than an 
unnecessarily larger 2,000 meter radius. The ability to monitor the 
near-field zone more effectively is an important consideration as the 
potential for more significant injurious effects has a higher 
likelihood of occurring close to the source, where sound pressures are 
highest.
    (2) Power-down or shutdown--It is impracticable for Shell (or other 
seismic operators) to shutdown airgun activities during low visibility 
or night-time conditions. ZSP is a relatively short activity that takes 
about 10-14 hours to complete; however, once it is started, any 
interruption would require the ZSP to be restarted, which would be 
impracticable and take more time for the company to complete the work. 
Furthermore, this would extend the survey duration longer than needed. 
In standard practice, NMFS typically requires that no startup of 
airguns will be allowed if the exclusion zone cannot be visually 
cleared prior to full array ramp up. Large seismic arrays are allowed 
to operate at night and during inclement weather when appropriate 
mitigation measures are in use, e.g., operating after a ramp-up in full 
visibility, or operating following mitigation gun operation for limited 
amounts of time following power downs or brief shutdowns.
    (3) Mitigation gun--NMFS recognizes that mitigation guns create 
noise underwater which, although lower than full-power seismic airguns, 
can adversely affect marine mammals in the nearby vicinity, and in the 
past several years has conditioned that mitigation guns only be used 
during turns for a maximum of 3 hours. While Shell's ZVSP array is 
stationary, the re-positioning from one session to the next will take 
more than 30 minutes. Therefore, limiting the mitigation gun to be used 
for a maximum of 30 minutes will require Shell to ramp-up after a 
session, which would extend the duration of the entire ZVSP program. 
Furthermore, the total ZVSP operations would only last for 20-28 hours. 
Therefore, working through the details of an operational adjustment to 
address this issue, NMFS determined there would be less environmental 
impact to allow the mitigation gun to operate longer than 30 minutes 
than require ramping up after a re-positioning and operating at a rate 
of 5 minutes per shoot.
    (4) Vessel anchoring with engines and depth sounders off--Although 
it is desirable to have less noise output from the proposed operations, 
NMFS also considers the safety issue as a critical factor to determine 
whether such proposed mitigation measures should be included. The 
following reasoning led NMFS to conclude, after consulting with Shell, 
that requiring vessels to have engines and depth sounders off while 
anchoring is not practicable for the industry operations.
     Anchoring:--Vessel Masters are responsible for crew safety 
and operation of their vessels in the open water Chukchi Sea. Vessel 
masters decide, based on numerous factors, safety being paramount, how 
the vessel maintains its position during stand-by periods. Vessels use 
slow transits to be able to continuously orient themselves relative to 
weather and swell directions to minimize vessel motion in the open 
ocean. Anchoring also restricts vessel flexibility to react quickly to 
sea state, weather, and work requirements. With regard to how vessels 
will be operated in the presence of marine mammals, each vessel will be 
staffed with PSOs when underway or in stand-by mode. PSOs will scan the 
area for marine mammals and advise the Vessel Master when marine 
mammals are in the vicinity of the vessel.
     Positioning vessels near acoustic stations:--Vessels would 
need to keep their generators and other auxiliary machinery operating 
when anchored.

[[Page 35767]]

Even though vessel propulsion noise would be eliminated, the auxiliary 
systems would continue to generate underwater noise that would 
significantly mask marine mammal calls on nearby recorders.
     Depth sounders:--These devices are highly directional in 
the downward direction. Little sound energy propagates horizontally 
away from the vessels to expose marine mammals to additional sounds. 
Turning off depth sounders is a safety concern that is not outweighed 
by the small potential benefit.

Reporting Measures

    Two modifications were made from the proposed IHA: (1) In the final 
IHA issued to Shell, NMFS requires Shell to submit daily PSO logs to 
NMFS as reasonably practicable, and (2) we removed proposed conditions 
of providing ZSVP and vessel SSV reports within 120 hour after the 
measurements. The reason for removing 120-hour ZSVP SSV reporting is 
due to safety concerns of recovering acoustic recorders during drilling 
operations. The rationale for removing vessel SSV reporting within 120 
hours is because vessel noises are not used to established exclusion 
zones and zones of influence, therefore, the is no need for a 120 hour 
quick turnaround for these reports. Both ZSVP and vessel SSVs will be 
reported in Shell's 90-day report.
(1) Submit daily PSO logs to NMFS as reasonably practicable.
(2) Field Reports
    Throughout the exploration drilling program, the PSOs will prepare 
a report each day or at such other interval as required summarizing the 
recent results of the monitoring program. The reports will summarize 
the species and numbers of marine mammals sighted. These reports will 
be provided to NMFS as required.
(3) Technical Reports
    The results of Shell's 2015 Chukchi Sea exploratory drilling 
monitoring program (i.e., vessel-based, aerial, and acoustic) will be 
presented in the ``90-day'' and Final Technical reports under the 
proposed IHA. Shell proposes that the Technical Reports will include: 
(1) Summaries of monitoring effort (e.g., total hours, total distances, 
and marine mammal distribution through study period, accounting for sea 
state and other factors affecting visibility and detectability of 
marine mammals); (2) analyses of the effects of various factors 
influencing detectability of marine mammals (e.g., sea state, number of 
observers, and fog/glare); (3) species composition, occurrence, and 
distribution of marine mammal sightings, including date, water depth, 
numbers, age/size/gender categories (if determinable), group sizes, and 
ice cover; (4) sighting rates of marine mammals during periods with and 
without drilling activities (and other variables that could affect 
detectability); (5) initial sighting distances versus drilling state; 
(6) closest point of approach versus drilling state; (7) observed 
behaviors and types of movements versus drilling state; (8) numbers of 
sightings/individuals seen versus drilling state; (9) distribution 
around the drilling units and support vessels versus drilling state; 
and (10) estimates of take by harassment. This information will be 
reported for both the vessel-based and aerial monitoring.
    Analysis of all acoustic data will be prioritized to address the 
primary questions, which are to: (a) Determine when, where, and what 
species of animals are acoustically detected on each AMAR ; (b) analyze 
data as a whole to determine offshore bowhead distributions as a 
function of time; (c) quantify spatial and temporal variability in the 
ambient noise; and (d) measure received levels of drilling unit 
activities. The detection data will be used to develop spatial and 
temporal animal distributions. Statistical analyses will be used to 
test for changes in animal detections and distributions as a function 
of different variables (e.g., time of day, time of season, 
environmental conditions, ambient noise, vessel type, operation 
conditions).
    Finally, the 90-day report should also include sightability curves 
and analysis overlaying visual and acoustic detections.
    The initial technical report is due to NMFS within 90 days of the 
completion of Shell's Chukchi Sea exploration drilling program. The 
``90-day'' report will be subject to review and comment by NMFS. Any 
recommendations made by NMFS must be addressed in the final report 
prior to acceptance by NMFS.
(4) Notification of Injured or Dead Marine Mammals
    Shell will be required to notify NMFS' Office of Protected 
Resources and NMFS' Stranding Network of any sighting of an injured or 
dead marine mammal. Based on different circumstances, Shell may or may 
not be required to stop operations upon such a sighting. Shell will 
provide NMFS with the species or description of the animal(s), the 
condition of the animal(s) (including carcass condition if the animal 
is dead), location, time of first discovery, observed behaviors (if 
alive), and photo or video (if available). The specific language 
describing what Shell must do upon sighting a dead or injured marine 
mammal appears in the IHA.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment]. Only take by Level B behavioral 
harassment is anticipated as a result of the proposed drilling program. 
Noise propagation from the drilling units, associated support vessels 
(including during 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 drilling 
units or support vessels. However, based on the flight paths and 
altitude, impacts from aircraft operations are anticipated to be 
localized and minimal in nature. Based on new information and through 
section 7 consultation under the Endangered Species Act (ESA), a few 
changes have been made to the underlying data and the methods used to 
calculate take, including: Updated density estimates for bowhead, gray, 
and beluga whales based on new survey data, the use of anticipated 
turnover rates of bowhead and ringed seals within the area, removal of 
level B harassment reduction factor for bowhead whales based on 
avoidance, and calculating the stock specific takes for the East 
Chukchi Sea and Beaufort Sea beluga whales separately. These changes 
are described in greater detail below.
    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 
Federal Register notice (80 FR 11726; March 4, 2015) for the proposed 
IHA. The potential effects of sound from the proposed exploratory 
drilling program without regard to any mitigation might include one or 
more of the following: Tolerance; masking of natural sounds; behavioral 
disturbance; non-auditory physical effects; and, at

[[Page 35768]]

least in theory, temporary or permanent hearing impairment (Richardson 
et al. 1995a). As discussed in the Federal Register notice (80 FR 
11726; March 4, 2015) for the proposed IHA, 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 Federal Register notice (80 FR 11726; March 4, 2015) for 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 proposed 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. The 
required monitoring and mitigation measures further reduce any 
potential for hearing impairment. Additionally, non-auditory 
physiological effects are anticipated to be minor, if any would occur 
at all.
    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 aggregate sources 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, and revised as mentioned above, in the following sections.
    Shell has 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 
narwhal. However, as stated previously in this document, sightings of 
this species are rare, and the likelihood of occurrence of narwhals in 
the proposed drilling area is minimal. Therefore, NMFS is not 
authorizing take of this species.

Basis for Estimating ``Take by Harassment''

    ``Take by Harassment'' is described in this section and was 
calculated in Shell's application by multiplying the three factors 
below, which provides the number of instances of take. In a couple of 
cases, other-species specific information is taken into consideration 
to help better understand the number of individuals taken. Following 
are the three factors:
     The expected densities of marine mammals that may occur 
near the exploratory drilling operations,
     The area of water likely to be exposed to continuous, non-
pulse sounds >=120 dB re 1 [mu]Pa (rms) during drilling unit operations 
or icebreaking activities and impulse sounds >=160 dB re 1 [mu]Pa (rms) 
created by seismic airguns during ZVSP activities, and
     The number of days of the applicable activity.
    Through the IHA process we determined that certain modifications to 
the take estimates were appropriate. Those are described in subsequent 
sections of this Notice (see Marine Mammal Density Estimates and 
Estimated Takes). The next subsection describes the estimated densities 
of marine mammals that may occur in the project area. The area of water 
that may be ensonified to the above sound levels is described further 
in the ``Individual Sound Sources and Level B Harassment Radii'' 
subsection.

Marine Mammal Density Estimates

    In the Federal Register notice (80 FR 11726; March 4, 2015) for the 
proposed IHA, a detailed description was provided on the marine mammal 
densities in the Chukchi Sea. However, NMFS later learned that data 
only included sighting data from 2012 and 2013 for bowhead, gray, and 
beluga whales. Upon consulting with NMFS Alaska Regional Office (AKRO) 
under section 7 of the Endangered Species Act and the National Marine 
Mammal Laboratory (NMML), we determined that using sighting data 
covering 2008-2014 will yield more accurate density estimates of these 
three species. In addition, NMFS also revised the detectability bias 
f(0) in density calculation for the bowhead whale based on Ferguson and 
Clarke (2013). Therefore, NMFS is revising the take estimates of 
bowhead, gray, and beluga whales in this section based on these updates 
to the density estimates.
    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 
activities are occurring: Open water or ice margin. More ice is likely 
to be present in the area of activities during the July-August period, 
so summer ice-margin densities have been applied to 50% of the area 
that may be ensonified from 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% of the area that may be ensonified from 
drilling and ZVSP activities in those months. Fall open-water densities 
were applied to the remaining 80 percent of the area. Since ice 
management activities would only occur within ice-margin habitat, the 
entire area potentially ensonified by ice management activities has 
been multiplied by the ice-margin densities in both seasons.
    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. In those cases, the mean and maximum 
estimates were determined from the reported densities or survey data. 
In other cases only one or no applicable estimate was available, so 
correction factors were used to arrive at ``average'' and ``maximum'' 
estimates. These are described in detail in the following subsections.
    Detectability bias, quantified in part by f(0), is associated with 
diminishing sightability with increasing lateral distance from the 
survey trackline. Availability bias, g(0), refers to the fact that 
there is <100% probability of sighting an animal that is present along 
the survey trackline. Some sources below included these correction 
factors in the reported densities (e.g., ringed seals in Bengtson et 
al. 2005) and the best available correction factors were applied to 
reported results when they had not already been included (e.g., Moore 
et al. 2000).
(1) Cetaceans
    Eight species of cetaceans are known to occur in the activity area. 
Three of the nine species, bowhead, fin, and humpback whales, are 
listed as ``endangered'' under the ESA.

[[Page 35769]]

(a) Beluga Whales
    Summer densities of beluga whales in offshore waters are expected 
to be low, with somewhat higher densities in ice-margin and nearshore 
areas. Past aerial surveys have recorded few belugas in the offshore 
Chukchi Sea during the summer months (Moore et al. 2000). More recent 
aerial surveys of the Chukchi Sea from 2008-2014 flown by the NMML as 
part of the COMIDA project, now part of the Aerial Surveys of Arctic 
Marine Mammals (ASAMM) project, reported 10 beluga sightings (22 
individuals) in offshore waters during 22,154 km of on-transect effort. 
Larger groups of beluga whales were recorded in nearshore areas, 
especially in June and July during the spring migration (Clarke et al. 
2012, 2013). Additionally, only one beluga sighting was recorded during 
>80,000 km of visual effort during good visibility conditions from 
industry vessels operating in the Chukchi Sea in September-October of 
2006-2010 (Hartin et al. 2013). If belugas are present during the 
summer, they are more likely to occur in or near the ice edge or close 
to shore during their northward migration. Effort and sightings 
reported by Clarke et al. (2012, 2013) were used to calculate the 
average open-water density estimate. The mean group size of the 
sightings was 2.2. A f(0) value of 2.841 and g(0) value of 0.58 from 
Harwood et al. (1996) were also used in the density calculation 
resulting in an average open-water density of 0.0010 belugas/km\2\. The 
highest density from the reported survey periods (0.0030 belugas/km\2\) 
has been used as the maximum density that may occur in open-water 
habitat. Specific data on the relative abundance of beluga in open-
water versus ice-margin habitat during the summer in the Chukchi Sea is 
not available. However, belugas are commonly associated with ice, so an 
inflation factor of four was used to estimate the ice-margin densities 
from the open-water densities. Very low densities observed from vessels 
operating in the Chukchi Sea during non-seismic periods and locations 
in July-August of 2006-2010 (0.0-0.0003/mi\2\, 0.0-0.0001/km\2\; Hartin 
et al. 2013), also suggest the number of beluga whales likely to be 
present near the planned activities will not be large.
    In the fall, beluga whale densities offshore in the Chukchi Sea are 
expected to be somewhat higher than in the summer because individuals 
of the eastern Chukchi Sea stock and the Beaufort Sea stock will be 
migrating south to their wintering grounds in the Bering Sea (Allen and 
Angliss 2012). Densities derived from survey results in the northern 
Chukchi Sea in Clarke and Ferguson and Clarke et al. (2012, 2013) were 
used as the average density for open-water season estimates. Clarke and 
Ferguson (in prep, cited in Shell 2014) and Clarke et al. (2012, 2013) 
reported 17 beluga sightings (28 individuals) during 22,255 km of on-
transect effort in water depths 36-50 m during the months of July 
through September. The mean group size of those three sightings was 
1.6. A f(0) value of 2.841 and a g(0) value of 0.58 from Harwood et al. 
(1996) were used to calculate the average open-water density of 0.0100 
belugas/km\2\. The highest density from the reported periods (0.0420 
belugas/km\2\) was again used as the maximum density that may occur in 
open-water habitat. Moore et al. (2000) reported lower than expected 
beluga sighting rates in open-water during fall surveys in the Beaufort 
and Chukchi seas, so an inflation value of four was used to estimate 
the ice-margin densities from the open-water densities. Based on the 
few beluga sightings from vessels operating in the Chukchi Sea during 
non-seismic periods and locations in September-November of 2006-2010 
(Hartin et al. 2013), the relatively low densities shown in Table 6-2 
in Shell's IHA application are consistent with what is likely to be 
observed form vessels during the planned exploration drilling 
activities.
(b) Bowhead Whales
    By July, most bowhead whales are northeast of the Chukchi Sea, 
within or migrating toward their summer feeding grounds in the eastern 
Beaufort Sea. No bowheads were reported during 10,686 km of on-transect 
effort in the Chukchi Sea by Moore et al. (2000). Bowhead whales were 
also rarely sighted in July-August of 2006-2010 during aerial surveys 
of the Chukchi Sea coast (Thomas et al. 2011). This is consistent with 
movements of tagged whales (ADFG 2010), all of which moved through the 
Chukchi Sea by early May 2009, and tended to travel relatively close to 
shore, especially in the northern Chukchi Sea.
    The estimate of the July-August open-water bowhead whale density in 
the Chukchi Sea was calculated from the three bowhead sightings (3 
individuals) and 22,154 km of survey effort in waters 36-50 m deep in 
the Chukchi Sea during July-August reported in Clarke and Ferguson (in 
prep, cited in Shell 2014) and Clarke et al. (2012, 2013). The mean 
group size from those sightings was 1. The group size value, along with 
a f(0) value of 1.15 and a g(0) value of 0.07, both from Thomas et al. 
(2002) were used to estimate a summer density of 0.0010 bowheads/km\2\. 
The two sightings recorded during 4,209 km of survey effort in 2011 
(Clarke et al. 2012) produced the highest annual bowhead density during 
July-August (0.0050 bowheads/km\2\) which was used as the maximum open-
water density. Bowheads are not expected to be encountered in higher 
densities near ice in the summer (Moore et al. 2000), so the same 
density estimates have been used for open-water and ice-margin 
habitats. Densities from vessel based surveys in the Chukchi Sea during 
non-seismic periods and locations in July-August of 2006-2010 (Hartin 
et al. 2013) ranged from 0.0002-0.0008/km\2\ with a maximum 95% CI of 
0.0085/km\2\.
    During the fall, bowhead whales that summered in the Beaufort Sea 
and Amundsen Gulf migrate west and south to their wintering grounds in 
the Bering Sea, making it more likely those bowheads will be 
encountered in the Chukchi Sea at this time of year. Moore et al. 
(2000) reported 34 bowhead sightings during 44,354 km of on-transect 
survey effort in the Chukchi Sea during September-October. Thomas et 
al. (2011) also reported increased sightings on coastal surveys of the 
Chukchi Sea during October and November of 2006-2010. GPS tagging of 
bowheads appear to show that migration routes through the Chukchi Sea 
are more variable than through the Beaufort Sea (Quakenbush et al. 
2010). Some of the routes taken by bowheads remain well north of the 
planned drilling activities while others have passed near to or through 
the area. Kernel densities estimated from GPS locations of whales 
suggest that bowheads do not spend much time (e.g., feeding or resting) 
in the north-central Chukchi Sea near the area of planned activities 
(Quakenbush et al. 2010). However, tagged whales did spend a 
considerable amount of time in the north-central Chukchi Sea in 2012, 
despite ongoing industrial activities in the region (ADFG 2012). Clarke 
et al. (2012, 2013) reported 72 sightings (86 individuals) during 
22,255 km of on-transect aerial survey effort in waters 36-50 m deep in 
2008-2012, the majority of which (53 sightings) were recorded in 2012. 
The mean group size of the 72 sightings was 1.2. The same f(0) and g(0) 
values that were used for the summer estimates above were used for the 
fall estimates resulting in an average September-October estimate of 
0.0230 bowheads/km\2\. The highest density form the survey periods 
(0.0780 bowheads/km\2\) was used as the maximum open-water density 
during the fall period. Moore et al. (2000) found that bowheads were 
detected more often than expected in association with ice in

[[Page 35770]]

the Chukchi Sea in September-October, so the ice-margin densities that 
are used are twice the open-water densities. Densities from vessel 
based surveys in the Chukchi Sea during non-seismic periods and 
locations in September-November of 2006-2010 (Hartin et al. 2013) 
ranged from 0.0003 to 0.0052/km\2\ with a maximum 95 percent CI of 
0.051/km\2\.
(c) Gray Whales
    Gray whale densities are expected to be much higher in the summer 
months than during the fall. Moore et al. (2000) found the distribution 
of gray whales in the planned operational area was scattered and 
limited to nearshore areas where most whales were observed in water 
less than 35 m deep. Thomas et al. (2011) also reported substantial 
declines in the sighting rates of gray whales in the fall. The average 
open-water summer density was calculated from 2008-2014 aerial survey 
effort and sightings in Clarke et al. (2012, 2013) for water depths 36-
50 m including 98 sightings (137 individuals) during 22,154 km of on-
transect effort. The average group size of those sightings was 1.4. 
Correction factors f(0) = 2.49 (Forney and Barlow 1998) and g(0) = 0.30 
(Forney and Barlow 1998, Mallonee 1991) were used to calculate and 
average open-water density of 0.0080 gray whales/km\2\. The highest 
density from the survey periods reported in Clarke et al. (2012, 2013) 
was 0.0300 gray whales/km\2\ and this was used as the maximum open-
water density. Gray whales are not commonly associated with sea ice, 
but may be present near it, so the same densities were used for ice-
margin habitat as were derived for open-water habitat during both 
seasons. Densities from vessel based surveys in the Chukchi Sea during 
non-seismic periods and locations in July-August of 2006-2010 (Hartin 
et al. 2013) ranged from 0.0008/km\2\ to 0.0085/km\2\ with a maximum 95 
percent CI of 0.0353 km\2\.
    In the fall, gray whales may be dispersed more widely through the 
northern Chukchi Sea (Moore et al. 2000), but overall densities are 
likely to be decreasing as the whales begin migrating south. A density 
calculated from effort and sightings (46 sightings [64 individuals] 
during 22,255 km of on-transect effort) in water 36-50 m deep during 
September-October reported by Clarke and Ferguson (in prep, cited in 
Shell 2014) and Clarke et al. (2012, 2013) was used as the average 
estimate for the Chukchi Sea during the fall period (0.0040 gray 
whales/km\2\). The corresponding group size value of 1.39, along with 
the same f(0) and g(0) values described above were used in the 
calculation. The maximum density from the survey periods (0.0080 gray 
whales/km\2\) was reported in 2013 (Clarke et al. 2013) and used as the 
maximum fall open-water density. Densities from vessel based surveys in 
the Chukchi Sea during non-seismic periods and locations in September-
November of 2006-2010 (Hartin et al. 2013) ranged from 0.0/km\2\ to 
0.0044/km\2\ with a maximum 95% CI of 0.0335 km\2\.
(d) Harbor Porpoises
    Harbor Porpoise densities were estimated from industry data 
collected during 2006-2010 activities in the Chukchi Sea. Prior to 
2006, no reliable estimates were available for the Chukchi Sea and 
harbor porpoise presence was expected to be very low and limited to 
nearshore regions. Observers on industry vessels in 2006-2010, however, 
recorded sightings throughout the Chukchi Sea during the summer and 
early fall months. Density estimates from 2006-2010 observations during 
non-seismic periods and locations in July-August ranged from 0.0013/
km\2\ to 0.0029/km\2\ with a maximum 95% CI of 0.0137/km\2\ (Hartin et 
al. 2013). The average density from the summer season of those three 
years (0.0022/km\2\) was used as the average open-water density 
estimate while the high value (0.0029/km\2\) was used as the maximum 
estimate (Table 6-1 in Shell's IHA application). Harbor porpoise are 
not expected to be present in higher numbers near ice, so the open-
water densities were used for ice-margin habitat in both seasons. 
Harbor porpoise densities recorded during industry operations in the 
fall months of 2006-2010 were slightly lower and ranged from 0.0/km\2\ 
to 0.0044/km\2\ with a maximum 95% CI of 0.0275/km\2\. The average of 
those years (0.0021/km\2\) was again used as the average density 
estimate and the high value (0.0044/km\2\) was used as the maximum 
estimate (Table 6-2 in Shell's IHA application).
(e) Other Whales
    The remaining five cetacean species that could be encountered in 
the Chukchi Sea during Shell's planned exploration drilling program 
include the humpback whale, killer whale, minke whale, and fin whale. 
Although there is evidence of the occasional occurrence of these five 
cetacean species in the Chukchi Sea, it is unlikely that more than a 
few individuals will be encountered during the planned exploration 
drilling program and therefore minimum densities have been assigned to 
these species (Tables 6-1 and 6-2 in Shell's IHA application). Clarke 
et al. (2011, 2013) and Hartin et al. (2013) reported humpback whale 
sightings; George and Suydam (1998) reported killer whales; Brueggeman 
et al. (1990), Hartin et al. (2013), Clarke et al. (2012, 2013), and 
Reider et al. (2013) reported minke whales; and Clarke et al. (2011, 
2013) and Hartin et al. (2013) reported fin whales. With regard to 
humpback and fin whales, NMFS (2013) recently concluded these whales 
occur in very low numbers in the project area, but may be regular 
visitors.
    Of these uncommon cetacean species, minke whale has the potential 
to be the most common based on recent industry surveys. Reider et al. 
(2013) reported 13 minke whale sightings in the Chukchi Sea in 2013 
during Shell's marine survey program. All but one minke whale sighting 
in 2013, however, were observed in nearshore areas despite only minimal 
monitoring effort in nearshore areas compared to more offshore 
locations near the Burger prospect (Reider et al. 2013).
(2) Pinnipeds
    Three species of pinnipeds under NMFS jurisdiction are likely to be 
encountered in the Chukchi Sea during Shell's planned exploration 
drilling program: Ringed seal, bearded seal, and spotted seal. Ringed 
and bearded seals are associated with both the ice margin and the 
nearshore area. The ice margin is considered preferred habitat (as 
compared to the nearshore areas) for ringed and bearded seals during 
most seasons. Spotted seals are often considered to be predominantly a 
coastal species except in the spring when they may be found in the 
southern margin of the retreating sea ice. However, satellite tagging 
has shown that they sometimes undertake long excursions into offshore 
waters during summer (Lowry et al. 1994, 1998). Ribbon seals have been 
reported in very small numbers within the Chukchi Sea by observers on 
industry vessels (Patterson et al. 2007, Hartin et al. 2013).
(a) Ringed and Bearded Seals
    Ringed seal and bearded seals ``average'' and ``maximum'' summer 
ice-margin densities were available in Bengtson et al. (2005) from 
spring surveys in the offshore pack ice zone (zone 12P) of the northern 
Chukchi Sea. However, corrections for bearded seal availability, g(0), 
based on haulout and diving patterns were not available. Densities of 
ringed and bearded seals in open water are expected to be somewhat 
lower in the summer when preferred pack ice habitat may still be 
present in the Chukchi Sea. Average and

[[Page 35771]]

maximum open-water densities have been estimated as \3/4\ of the ice 
margin densities during both seasons for both species. The fall density 
of ringed seals in the offshore Chukchi Sea has been estimated as \2/3\ 
the summer densities because ringed seals begin to reoccupy nearshore 
fast ice areas as it forms in the fall. Bearded seals may also begin to 
leave the Chukchi Sea in the fall, but less is known about their 
movement patterns so fall densities were left unchanged from summer 
densities. For comparison, the ringed seal density estimates calculated 
from data collected during summer 2006-2010 industry operations ranged 
from 0.0138/km\2\ to 0.0464/km\2\ with a maximum 95 percent CI of 
0.1581/km\2\ (Hartin et al. 2013).
(b) Spotted Seals
    Little information on spotted seal densities in offshore areas of 
the Chukchi Sea is available. Spotted seal densities in the summer were 
estimated by multiplying the ringed seal densities by 0.02. This was 
based on the ratio of the estimated Chukchi populations of the two 
species. Chukchi Sea spotted seal abundance was estimated by assuming 
that 8% of the Alaskan population of spotted seals is present in the 
Chukchi Sea during the summer and fall (Rugh et al. 1997), the Alaskan 
population of spotted seals is 59,214 (Allen and Angliss 2012), and 
that the population of ringed seals in the Alaskan Chukchi Sea is 
~208,000 animals (Bengtson et al. 2005). In the fall, spotted seals 
show increased use of coastal haulouts so densities were estimated to 
be \2/3\ of the summer densities.
(c) Ribbon Seals
    Four ribbon seal sightings were reported during industry vessel 
operations in the Chukchi Sea in 2006-2010 (Hartin et al. 2013). The 
resulting density estimate of 0.0007/km\2\ was used as the average 
density and 4 times that was used as the maximum for both seasons and 
habitat zones.

Individual Sound Sources and Level B Harassment Radii

    The assumed start date of Shell's exploration drilling program in 
the Chukchi Sea using the drilling units Discoverer and Polar Pioneer 
with associated support vessels is 4 July. Shell may conduct 
exploration drilling activities at up to four drill sites at the 
prospect known as Burger. Drilling activities are expected to be 
conducted through approximately 31 October 2015.
    Previous IHA applications for offshore Arctic exploration programs 
estimated areas potentially ensonified to >=120 or >=160 dB re 1[mu]Pa 
rms independently for each continuous or pulsed sound source, 
respectively (e.g., drilling, ZVSP, etc.). The primary method used in 
this IHA application for estimating areas ensonified to continuous 
sound levels >=120 dB re 1[mu]Pa rms by drilling-related activities 
involved sound propagation modeling of a variety of scenarios 
consisting of multiple, concurrently-operating sound sources. These 
``activity scenarios'' consider additive acoustic effects from multiple 
sound sources at nearby locations, and more closely capture the nature 
of a dynamic acoustic environment where numerous activities are taking 
place simultaneously. The area ensonified to >=160 dB re 1[mu]Pa rms 
from ZVSP, a pulsed sound source, was treated independently from the 
activity scenarios for continuous sound sources.
    The continuous sound sources used for sound propagation modeling of 
activity scenarios included (1) drilling unit and drilling sounds, (2) 
supply and drilling support vessels using DP when tending to a drilling 
unit, (3) MLC construction, (4) anchor handling in support of mooring a 
drilling unit, and (5) ice management activities. The information used 
to generate sound level characteristics for each continuous sound 
source is summarized below to provide background on the model inputs. A 
``safety factor'' of 1.3 dB re 1[mu]Pa rms was added to the source 
level for each sound source prior to modeling activity scenarios to 
account for variability across the project area associated with 
received levels at different depths, geoacoustical properties, and 
sound-speed profiles. The addition of the 1.3 dB re 1 [mu]Pa rms safety 
factor to source levels resulted in an approximate 20 percent increase 
in the distance to the 120 dB re 1[mu]Pa rms threshold for each 
continuous source.
    Table 3 summarizes the 120 dB re 1 [mu]Pa rms radii for individual 
sound sources, both the ``original'' radii as measured in the field, 
and the ``adjusted'' values that were calculated by adding the ``safety 
factor'' of 1.3 dB re 1 [mu]Pa rms to each source. The adjusted source 
levels were then used in sound propagation modeling of activity 
scenarios to estimate ensonified areas and associated marine mammal 
exposure estimates. Additional details for each of the continuous sound 
sources presented in Table 3 are discussed below.
    The pulsed sound sources used for sound propagation modeling of 
activity scenarios consisted of two small airgun arrays proposed for 
ZVSP activities. All possible array configurations and operating depths 
were modeled to identify the arrangement with the greatest sound 
propagation characteristics. The resulting >=160 dB re 1[mu]Pa rms 
radius was multiplied by 1.5 as a conservative measure prior to 
estimating exposed areas, which is discussed in greater detail below.

     Table 3--Measured and Adjusted 120 dB re 1 [micro]Pa Radii for
                  Individual, Continuous Sound Sources
------------------------------------------------------------------------
                                          Radii of 120 dB re 1 [micro]Pa
                                              (rms) isopleth (meters)
                                         -------------------------------
    Activity/Continuous sound source                        With 1.3 dB
                                             Original       correction
                                            measurement       factor
------------------------------------------------------------------------
Drilling at 1 site......................           1,500           1,800
Vessel in DP............................           4,500           5,500
Mudline cellar construction at 1 site...           8,200           9,300
Anchor handling at 1 site (assumed to be          19,000          22,000
 2 vessels).............................
Single vessel ice management............           9,600          11,000
------------------------------------------------------------------------

    Two sound sources have been proposed by Shell for the ZVSP surveys 
in 2015. The first is a small airgun array that consists of three 150 
in\3\ (2,458 cm\3\) airguns for a total volume of 450 in\3\ (7,374 
cm\3\). The second ZVSP sound source consists of two 250 in\3\ (4,097 
cm\3\) airguns with a total volume of 500 in\3\ (8,194 cm\3\). Sound 
footprints for each of the two proposed ZVSP airgun array 
configurations were estimated using JASCO Applied Sciences' MONM.

[[Page 35772]]

The model results were maximized over all water depths from 9.8 to 23 
ft (3 to 7 m) to yield precautionary sound level isopleths as a 
function of range and direction from the source. The 450 in\3\ airgun 
array at a source depth of 7 m yielded the maximum ranges to the >=190, 
>=180, and >=160 dB re 1 [mu]Pa rms isopleths.
    There are two reasons that the radii for the 450 in\3\ airgun array 
are larger than those for the 500 in\3\ array. First, the sound energy 
does not scale linearly with the airgun volume, rather it is 
proportional to the cube root of the volume. Thus, the total sound 
energy from three airguns is larger than the total energy from two 
airguns, even though the total volume is smaller. Second, larger volume 
airguns emit more low-frequency sound energy than smaller volume 
airguns, and low-frequency airgun sound energy is strongly attenuated 
by interaction with the surface reflection. Thus, the sound energy for 
the larger-volume array experiences more reduction and results in 
shorter sound threshold radii.
    The estimated 95th percentile distances to the following thresholds 
for the 450 in\3\ airgun array were: >=190 dB re 1 [mu]Pa rms = 170 m, 
>=180 dB re 1 [mu]Pa rms = 920 m, and >=160 dB re 1 [mu]Pa rms = 7,970 
m. The >=160 dB re 1 [mu]Pa rms distance was multiplied by 1.5 for a 
distance of 11,960 m. This radius was used for estimating areas 
ensonified by pulsed sounds to >=160 dB re 1 [mu]Pa rms during a single 
ZVSP survey. ZVSP surveys may occur at up to two different drill sites 
during Shell's planned 2015 exploration drilling program in the Chukchi 
Sea.
    As noted above, previous IHA applications for Arctic offshore 
exploration programs estimated areas potentially ensonified to 
continuous sound levels >=120 dB re 1[mu]Pa rms independently for each 
sound source. This method was appropriate for assessing a small number 
of continuous sound sources that did not consistently overlap in time 
and space. However, many of the continuous sound sources described 
above will operate concurrently at one or more nearby locations in 2015 
during Shell's planned exploration drilling program in the Chukchi Sea. 
It is therefore appropriate to consider the concurrent operation of 
numerous sound sources and the additive acoustic effects from combined 
sound fields when estimating areas potentially exposed to levels >=120 
dB re 1 [mu]Pa rms.
    A range of potential ``activity scenarios'' was derived from a 
realistic operational timeline by considering the various combinations 
of different continuous sound sources that may operate at the same time 
at one or more locations. The total number of possible activity 
combinations from all sources at up to four different drill sites would 
not be practical to assess or present in a meaningful way. 
Additionally, combinations such as concurrent drilling and anchor 
handling in close proximity do not add meaning to the analysis given 
the negligible contribution of drilling sounds to the total area 
ensonified by such a scenario. For these reasons, various combinations 
of similar activities were grouped into representative activity 
scenarios shown in Table 4. Ensonified areas for these representative 
activity scenarios were estimated through sound propagation modeling. 
Activity scenarios were modeled for different drill site combinations 
and, as a conservative measure, the locations corresponding to the 
largest ensonified area were chosen to represent the given activity 
scenario. In other words, by binning all potential scenarios into the 
most conservative representative scenario, the largest possible 
ensonified areas for all activities were identified for analysis. A 
total of nine representative activity scenarios were modeled to 
estimate areas exposed to continuous sounds >=120 dB re 1 [mu]Pa rms 
for Shell's planned 2015 exploration drilling program in the Chukchi 
Sea (Table 4). A tenth scenario was included for the ZVSP activities.

 Table 4--Sound Propagation Modeling Results of Representative Drilling Related Activity Scenarios and Estimates
   of the Total Area Potentially Ensonified Above Threshold Levels at the Burger Prospect in the Chukchi Sea,
                        Alaska, During Shell's Proposed 2015 Exploration Drilling Program
----------------------------------------------------------------------------------------------------------------
                                                                                    Area potentially ensonified
                                                                     Threshold                (km\2\)
                  Activity scenario description                   level (dB re 1 -------------------------------
                                                                  [micro]Pa rms)      Summer           Fall
----------------------------------------------------------------------------------------------------------------
Drilling at 1 site..............................................             120            10.2            10.2
Drilling and DP vessel at 1 site................................             120           111.8           111.8
Drilling and DP vessel (1 site) + drilling and DP vessel (2nd                120           295.5           295.5
 site)..........................................................
Mudline cellar construction at 2 different sites................             120           575.5           575.5
Anchor handling at 1 site.......................................             120         1,534.9         1,534.9
Drilling and DP vessel at 1 site + anchor handling at 2nd site..             120         1,759.2         1,759.2
Mudline cellar construction at 2 different sites + anchor                    120         2,046.3         2,046.3
 handling at 3rd site...........................................
Two-vessel ice management.......................................             120           937.4           937.4
Four-vessel ice management......................................             120         1,926.0         1,926.0
ZVSP at 2 different sites.......................................             160             0.0           898.0
----------------------------------------------------------------------------------------------------------------

Estimated Takes

    This section provides estimates of the number of individuals 
potentially exposed to continuous sound levels >=120 dB re 1 [mu]Pa rms 
from exploration drilling related activities and pulsed sound levels 
>=160 dB re 1 [mu]Pa rms by ZVSP activities. The estimates are based on 
a consideration of the number of exposures of marine mammals to Shell's 
drilling operations in the Chukchi Sea during 2015 in the anticipated 
area ensonified to those sound levels, as well as the duration of the 
activities.
    To account for different densities in different habitats, Shell has 
assumed that more ice is likely to be present in the area of operations 
during the July-August period than in the September-October period, so 
summer ice-margin densities have been applied to 50% of the area that 
may be exposed to sounds from exploration drilling activities in those 
months. Open water densities in the summer were applied to the 
remaining 50% of the area.
    Less ice is likely to be present during the September-October 
period than in the July-August period, so fall ice-margin densities 
have been applied to only 20% of the area that may be exposed to sounds 
from exploration drilling activities in those months. Fall open-water 
densities were applied to the remaining 80% of the area. Since

[[Page 35773]]

icebreaking activities would only occur within ice-margin habitat, the 
entire area potentially ensonified by icebreaking activities has been 
multiplied by the ice-margin densities in both seasons.
    Estimates of the numbers of marine mammals potentially exposed to 
continuous sounds >=120 dB re 1 [mu]Pa rms or pulsed sounds >=160 dB re 
1 [mu]Pa rms are based on assumptions that include upward scaling of 
source levels for all sound sources, 100% ``turnover'' of individuals 
in ensonified areas every 24 hours (except for bowhead whales and 
ringed seals, as discussed below), and no decrease in the number of 
takes resulting from anticipated avoidance behaviors. These estimates 
are likely conservative given some of the buffers Shell included in 
their ensonified area estimates and the fact that the estimates 
indicate the likely instances of take, but are expected to overestimate 
the numbers of individuals, since we expect that the instances include 
repeated exposures of some individuals (meaning the number of 
individuals is lower), which is not quantitatively accounted for in any 
species except bowheads and ringed seals.
    The following sections present exposure estimates for bowhead 
whales and ringed seals. Estimates were generated based on an 
evaluation of the best available science and a consideration of the 
assumptions above.
    It is difficult to determine an average turnover time for 
individual bowhead whales in a particular area of the Chukchi Sea. 
Reasons for this include differences in residency time between 
migratory and non-migratory periods, changes in distribution of food 
and other factors such as behavior that influence animal movement, 
variation among individuals, etc.
    Complete turnover of individual bowhead whales in the project area 
each 24-hour period is possible during distinct periods within the fall 
migration when bowheads are traveling through the area, however, 
bowheads often move in pulses with one to several days between major 
pulses of whales (Miller et al. 2002). Gaps between groups of traveling 
whales during fall migration result in days when no bowhead whales 
would be expected to be present in the activity area. The absence of 
bowhead whales during periods of the fall migration can likely be 
attributed to individuals stopping to feed opportunistically when food 
is encountered, which is known to occur annually in an area north of 
Barrow (Citta et al. 2014). The extent of feeding by bowhead whales 
during fall migration across other areas of the Chukchi Sea varies 
greatly from year to year based on the location and abundance of prey 
(Shelden and Mocklin 2013). For these reasons, NMFS believes a 24-hour 
turnover period for bowhead whales is unnecessarily conservative and 
has selected a turnover rate of 48 hours to estimate exposures. Using 
the projected 2015 bowhead whale population of 19,534, which is based 
on the Givens et al. (2013) bowhead whale abundance estimate of 16,892 
individuals in 2011 with an annual growth rate of 3.7%, a reasonable 
estimate of individual exposures, as discussed above, to be associated 
with the assumptions of no avoidance and a 48-hour turnover period, is 
2,582 individuals, or 5.5% of the projected 2015 bowhead whale 
population.
    For ringed seals, satellite tagging data from tagging studies from 
a joint research by the State of Alaska Department of Fish and Game's 
Marine Mammals Program, the Ice Seal Committee, and interested seal 
hunters from villages along the west and north coasts of Alaska were 
used to derive a turnover rate for this species. Data from these tagged 
animals showed that in addition to a long distance seasonal migration, 
there are many instances from July through September when individual 
ringed seals stayed in a relatively small area (compared to their 
migration route) up to multiple weeks, including on and around the 
offshore continental shelf leased blocks. In addition, Patterson et al. 
2014 indicate a turnover period of a week or more for individual seals 
near a drilling operation in the Alaskan Arctic may be more 
appropriate, based on the 6-24 day area occupancy described above. 
These results suggest that assuming 100% turnover of all individual 
seals around an offshore drilling operation on a daily basis is 
unreasonable, and a period closer to a week may be more appropriate and 
yet still conservative for other individuals that remained in the area 
for longer periods.
    Thus, NMFS considers the estimate associated with 24-hour turnover 
and zero avoidance to be an overestimate of the numbers of individual 
ringed seals. We have determined a 48-hour turnover rate to be more 
realistic, and still very conservative.
    For beluga whales, challenges arise when one attempts to derive 
density and exposure estimates separately for the two stocks as they 
overlap in time and space in the Chukchi Sea, particularly within the 
specified geographic region (i.e., the lease area), and the physical 
characteristics of individuals from the two stocks do not allow 
differentiation during visual surveys.
    Beluga whale densities used to estimate potential exposures were 
calculated from aerial survey data collected by the NMML from July 
through October of 2008-2014. To reflect differences in abundance 
between seasons, data from July and August were pooled to produce a 
``Summer'' density and data from September and October were pooled to 
produce a ``Fall'' density. Since individuals of the two stocks cannot 
be distinguished visually, these data represent individuals from both 
stocks to the extent that both stocks are present in the Chukchi Sea 
during the two seasons.
    Few individuals from either stock are likely to be present near the 
planned activities in July and August because the spring migrations of 
both stocks beyond the lease sale area are largely complete by early 
July. The spring migration of the Beaufort Sea Stock occurs much 
earlier in the season compared to the Chukchi Sea stock, thus, beluga 
whales present in the Chukchi Sea in July and August are most likely 
from the Eastern Chukchi Sea Stock. It is therefore assumed that the 
average observed Summer (July-August) density of 0.0010 individuals/
km\2\ is entirely composed of individuals from the Eastern Chukchi Sea 
Stock.
    Since the two stocks migrate at similar times through the Chukchi 
Sea in the fall and one cannot distinguish them visually, the pooled 
September-October beluga density received from NMML (0.0100 
individuals/km\2\) represents the presence of both stocks. The current 
abundance estimate for the Eastern Chukchi Sea Stock is 3,710 
individuals and the abundance estimate for the Beaufort Sea Stock is 
39,258 individuals (Allen and Angliss 2014), resulting in a combined 
total estimate of 42,968 individuals. The Eastern Chukchi Sea Stock is, 
therefore, considered to represent 8.6% of the combined population and 
the Beaufort Sea Stock is considered to represent 91.4% of the same. 
Multiplying the observed density of 0.0100 individuals/km\2\ by these 
percentages results in a density estimate of 0.0009 individuals/km\2\ 
for the Eastern Chukchi Sea Stock and 0.0091 individuals/km\2\ for the 
Beaufort Sea Stock. The Eastern Chukchi Sea Stock density estimate for 
the Fall period is therefore slightly lower than the density estimate 
for the Summer.
    Based on the information above, a method was derived to calculate 
the takes of beluga whales by assuming that (1) all beluga whales 
encountered in the

[[Page 35774]]

summer at the proposed project area are from the East Chukchi Sea 
population; and (2) composition of beluga whales encountered in the 
fall at the proposed project area reflects the relative proportion of 
the sizes of both stocks. Based on this method, the total number of 
individuals potentially exposed from the Eastern Chukchi Sea Stock 
would be approximately 344 (9.3% of estimated population of 3,710) 
while the number of individuals from the Beaufort Sea Stock would be 
approximately 1,318 (3.4% of the estimated population of 39,258). Table 
5 presents the exposure estimates for Shell's proposed 2015 exploration 
drilling program in the Chukchi Sea. The table also summarizes 
abundance estimates for each species and the corresponding percent of 
each population that may be exposed to continuous sounds >=120 dB re 1 
[mu]Pa rms or pulsed sounds >=160 dB re 1 [mu]Pa rms taking into 
account assigned turnover rates. With the exception of the exposure 
estimate for bowhead whales and ringed seals described above, where we 
had additional information to inform a turnover estimate, estimates for 
all other species assume 100% daily turnover and no avoidance of 
activities or ensonified areas.

 Table 5--The Total Number of Potential Exposures of Marine Mammals to Sound Levels >=120 dB re 1 [mu]Pa rms or
    >=160 dB re 1 [mu]Pa rms During the Shell's Proposed Drilling Activities in the Chukchi Sea, Alaska, 2015
                           [Estimates are also shown as a percent of each population]
----------------------------------------------------------------------------------------------------------------
                                                                                      Number         Estimated
                             Species                                 Abundance       potential      population
                                                                                     exposure        (percent)
----------------------------------------------------------------------------------------------------------------
Beluga (Beaufort Sea)...........................................          42,968           1,318             3.4
Beluga (E. Chukchi Sea).........................................           3,710             344             9.3
Killer whale....................................................           2,084              14             0.8
Harbor porpoise.................................................          48,215             294             0.6
Bowhead whale...................................................          19,534           1,083             5.5
Fin whale.......................................................           1,652              14             0.8
Gray whale......................................................          19,126             834             4.4
Humpback whale..................................................          20,800              14             0.1
Minke whale.....................................................             810              41             5.1
Bearded seal....................................................         155,000           1,722             1.1
Ribbon seal.....................................................          49,000              96             0.2
Ringed seal.....................................................         300,000          25,217             8.4
Spotted seal....................................................         141,479           1,007             0.7
----------------------------------------------------------------------------------------------------------------

    In summary, several precautionary methods were applied when 
calculating exposure estimates. These conservative methods and related 
considerations include:
     Application of a 1.3 dB re 1 [mu]Pa rms safety factor to 
the source level of each continuous sound source prior to sound 
propagation modeling of areas exposed to Level B harassment thresholds;
     Binning of similar activity scenarios into a 
representative scenario, each of which reflected the largest exposed 
area for a related group of activities;
     Modeling numerous iterations of each activity scenario at 
different drill site locations to identify the spatial arrangement with 
the largest exposed area for each;
     Assuming 100 percent daily (or 24-hour) turnover of 
populations (except for bowhead whales and ringed seals), which likely 
overestimates the number of different individuals that would be 
exposed, especially during non-migratory periods; and
     Density estimates for some cetaceans include nearshore 
areas where more individuals would be expected to occur than in the 
offshore Burger Prospect area (e.g., gray whales).
    Additionally, post-season estimates of the numbers of marine 
mammals exposed to Level B harassment thresholds per Shell's 90-day 
report from the 2012 IHA consistently support the methods used in 
Shell's IHA applications as precautionary. Most recently, exposure 
estimates reported by Reider et al. (2013) from Shell's 2012 
exploration activities in the Chukchi Sea were considerably lower than 
those requested in Shell's 2012 IHA application. The above summary of 
the numbers of cetaceans and pinnipeds that may be exposed to sounds 
above Level B harassment thresholds is best interpreted as 
conservatively high, especially for species for which a correction 
factor has not been included to account for animals staying in an area 
for more than 24 hours at a time (e.g, other than ringed seals, 
bowheads), particularly the larger number for each species that assumes 
a new group of individuals each day.

Analysis and Determinations

Negligible Impact

    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). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes, 
alone, is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, effects on habitat, and the status 
of the species. To avoid repetition, we provide some general analysis 
immediately below that applies to all the species listed in Table 5, 
given that some of the anticipated effects (or lack thereof) of this 
project on marine mammals are expected to be relatively similar in 
nature. However, below that, we break our analysis into species, or 
groups of species where relevant similarities exist, to provide more 
specific information related to the anticipated effects on individuals 
or where there is information about the size, status, or structure of 
any species or stock that would lead to a differing

[[Page 35775]]

assessment of the effects on the population.
    Taking into account the required mitigation and related monitoring, 
no injuries or mortalities to any species are anticipated to occur as a 
result of Shell's proposed Chukchi Sea exploratory drilling program, 
and none are authorized. 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. 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 mitigate the 
potential for an oil spill of any size. NMFS does not authorize take 
from an oil spill, as it is not part of the specified activity.
Bowhead Whales
    Bowhead whales are less likely to occur in the proposed 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).
    It is estimated that a maximum of 1,083 bowhead whales (5.5%) could 
be taken by Level B harassment. Potential impacts to bowhead whales 
from Shell's exploration drilling activity would be limited to brief 
behavioral disturbances and temporary avoidance of the ensonified 
areas.
    In their westward migration route, bowhead whales have been 
observed to feed in the vicinity of Shell's leases in the Chukchi Sea. 
However, the closest primary feeding ground is near Point Barrow, which 
is more than 150 mi (241 km) east of Shell's Burger prospect (Clarke et 
al. 2015). Therefore, if bowhead whales stop to feed near Point Barrow 
during Shell's proposed operations, the animals would not be exposed to 
continuous sounds from the drilling units or icebreaker above 120 dB or 
to impulsive sounds from the airguns above 160 dB, as those sound 
levels only propagate 1.8 km, 11 km, and 11.9 km, respectively, which 
includes the inflation factor.
    As stated earlier, the proposed activity is located in an area 
where bowhead whale mother/calf pairs are sighted in the month of 
October (Clarke et al. 2015). However, as discussed previously, noise 
exposure to bowhead whales is expected to be low and would in the worst 
case cause Level B harassment in the form of mild and temporary 
behavioral modification and/or avoidance. Moreover, the majority of the 
ensonified areas (67%) would fall between 120 and 126 dB re 1 [mu]Pa 
for non-impulse noise and 160 and 166 dB re 1 [mu]Pa for impulse noise, 
which at the low-end of the range for Level B behavioral harassment by 
noise exposure. Also, as noted above, the ensonified areas themselves 
from Shell's exploration drilling operation are small in comparison to 
the much larger bowhead whale reproduction BIA in October (Clarke et 
al. 2015). The size of the ensonified area depends on the type of 
activities (drilling, anchor handling, ice management, ZVSP, etc.), 
with the worst case scenario being mudline cellar construction at 2 
different sites and anchor handling at a third site (Table 4), which is 
expected to occur only 6 days each in summer and fall (Shell 2014). 
Therefore, NMFS believes that the potential adverse effects on bowhead 
whales cow/calf pairs while in their reproduction BIA in the northeast 
Chukchi Sea in October from Shell's exploration drilling activities 
will be limited in both number and severity, and that the potential 
worst case impacts would be mild and temporary behavioral reactions 
and/or avoidance of the affected area.
Beluga Whale
    Beluga whales are less likely to occur in the proposed 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. There is limited data to 
differentiate beluga whales from different stock in regards to the 
potential takes. Regardless of these limitations, there is a 
substantial body of data to support the conclusion that individuals 
from both stocks will react to continuous and impulse sounds in a 
similar way (i.e., short-term behavioral disturbance) and that any 
ensuing effects will be negligible despite the fact that the two stocks 
differ in estimated abundance
    It is estimated that a maximum of 1,318 whales from the Beaufort 
Sea stock (3.4%) and 344 whales from the East Chukchi Sea stock (9.3%) 
of beluga whales could be taken by Level B harassment. Potential 
impacts to beluga whales from Shell's exploration drilling activity 
include brief behavioral disturbances and temporary avoidance of the 
ensonified areas.
    No biologically important area exists for beluga whales in the 
vicinity of Shell's exploration drilling activities (Clarke et al. 
2015).
Gray Whales
    Gray whales occur in the northeastern Chukchi Sea during the summer 
and early fall to feed. Gray whales were often seen feeding in 
September and October near Hanna Shoal in the late 1980s and early 
1990s (Clarke and Moore, 2002), but they have been seen there rarely 
during aerial surveys since 2008. Therefore, Hanna Shoal is not 
considered as a biologically important area for gray whale feeding 
(Clarke et al. 2013; 2015).
    It is estimated that a maximum of 834 gray whales ([4.4%) could be 
taken by Level B harassment. Potential impacts to gray whales from 
Shell's exploration drilling activity will be limited to brief 
behavioral disturbances and temporary avoidance of the ensonified 
areas.
    No biologically important area exists for gray whales overlaps with 
Shell's exploration drilling area (the gray whale reproduction and 
feeding BIAs during the summer and fall are approximately 75-100 km 
from Shell's study area (Clarke et al. 2015)).
Other Cetaceans (Less Frequently Encountered Species)
    Other cetacean species are much rarer in the proposed project area. 
Killer whales, harbor porpoises, fin whales, humpback whales, and minke 
whales are species less frequently encountered in the vicinity of 
Shell's exploration drilling area. The exposure of these cetaceans to 
sounds produced by exploratory drilling operations (i.e., drilling 
units, ice management/icebreaking, and airgun operations) is not 
expected to result in more than Level B harassment. No biologically 
important areas exist for these less frequently encountered species in 
the vicinity of Shell's exploration drilling activities.
Ringed Seals
    Ringed seals are the most abundant pinniped species to be 
encountered in the proposed Shell exploration drilling

[[Page 35776]]

area. However, as stated in the Federal Register notice (80 FR 11726; 
March 4, 2015) for the proposed IHA, they appear to be more tolerant of 
anthropogenic sound, especially at lower received levels, than other 
marine mammals, such as mysticetes. Shell's proposed activities would 
occur at a time of year when ringed seals found in the region are not 
molting, breeding, or pupping. Therefore, these important life 
functions would not be impacted by Shell's proposed activities. The 
exposure of pinnipeds to sounds produced by Shell's proposed 
exploratory drilling operations in the Chukchi Sea is not expected to 
result in more than Level B harassment of individuals from ringed 
seals.
    It is estimated that maxima of 25,217 ringed seals (8.4%) could be 
taken by Level B harassment. After taking into account our revised 
turnover rate, this is a reduction from the 16.8% estimate presented in 
our Federal Register Notice of Proposed IHA. Potential impacts to these 
species from Shell's exploration drilling activity include brief 
behavioral disturbances and temporary avoidance of the ensonified 
areas.
    No biologically important area exists for seals in the vicinity of 
Shell's exploration drilling activities.
Other Pinnipeds (Less Frequently Encountered Species)
    Few other seals are expected to occur in the proposed project area, 
as several of the species prefer more nearshore waters. Additionally, 
as stated in the Federal Register notice (80 FR 11725; March 4, 2015) 
for the proposed IHA, pinnipeds appear to be more tolerant of 
anthropogenic sound, especially at lower received levels, than other 
marine mammals, such as mysticetes. Shell's proposed 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 proposed activities. The 
exposure of pinnipeds to sounds produced by Shell's proposed 
exploratory drilling operations in the Chukchi Sea is not expected to 
result in more than Level B harassment of individuals from the affected 
species or stocks.
    It is estimated that maxima of 1,722 bearded seal, 96 ribbon seals, 
and 1,007 spotted seals could be taken by Level B harassment. Potential 
impacts to these species from Shell's exploration drilling activity 
include brief behavioral disturbances and temporary avoidance of the 
ensonified areas.
    No biologically important area exists for seals in the vicinity of 
Shell's exploration drilling activities.
    Of the 12 marine mammal species or stocks likely to occur in the 
proposed drilling area, four are listed as endangered or threatened 
under the ESA: The bowhead, humpback, fin whales, and ringed seal. All 
four species are also designated as ``depleted'' under the MMPA. 
Nevertheless, the Bering-Chukchi-Beaufort stock of bowheads has been 
increasing at a rate 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 proposed activity area.
    Arctic ringed seals are listed as a threatened species under the 
ESA and are depleted under the MMPA. NMFS also listed the Beringia 
bearded seal DPS as threatened, but in July 2014 the U.S. District 
Court for the District of Alaska vacated the listing rule and remanded 
the rule to NMFS to correct the deficiencies identified in the opinion. 
An appeal is pending; in the interim the species is not listed under 
the ESA. None of the other species that may occur in the project area 
is listed as threatened or endangered under the ESA or designated as 
depleted under the MMPA. There is currently no established critical 
habitat in the proposed project area for any ESA-listed species. NMFS 
proposed critical habitat for Arctic ringed seals in December 2014, 
with a 90-day public comment period that was extended through March 31, 
2015. No final rule has been issued.
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see the ``Anticipated Effects on Habitat'' 
section). Although some disturbance is possible to food sources of 
marine mammals, the impacts are anticipated to be minor. Based on the 
vast size of the Arctic Ocean where feeding by marine mammals occurs 
versus the localized area of the drilling program, and the absence of 
any known areas of particular importance in the area of Shell's 
drilling activities, any missed feeding opportunities in the direct 
project area would be of little consequence, as marine mammals would 
have access to other feeding grounds.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS finds that the taking of marine mammals from Shell's 
proposed 2015 open-water exploration drilling program in the Chukchi 
Sea is not reasonably likely to adversely affect the species or stocks 
through effects on annual rates of recruitment or survival and 
therefore will have a negligible impact on the affected marine mammal 
species or stocks.

Small Numbers

    The estimated takes proposed to be authorized represent less than 
1% of the affected population or stock for six of the species and less 
than 5.5% for five additional species. The estimated take for ringed 
seals is 8.4%, and the estimated take for East Chukchi Sea beluga 
whales is 9.3%. 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, a 1.3 dB safety factor was applied to the source level 
of each continuous sound source prior to sound propagation modeling of 
areas exposed to Level B thresholds, which make the effective zones for 
take calculation larger than they likely would be. In addition, Shell 
applied binning of similar activity scenarios into a representative 
scenario, each of which reflected the largest exposed area for a 
related group of activities. Further, the take estimates assume 100% 
daily turnover of animals (with the exception of bowhead whales and 
ringed seals, for which a still conservative 48-hour turnover rate is 
assumed), which likely overestimates the number of different 
individuals that would be exposed, especially during non-migratory 
periods. Finally, density estimates for some cetaceans include 
nearshore areas

[[Page 35777]]

where more individuals would be expected to occur than in the offshore 
Burger Prospect area (e.g., gray whales).
    Based on the analysis contained herein of the estimated takes of 
marine mammals, NMFS finds that small numbers of marine mammals will be 
taken relative to the population sizes of the affected species or 
stocks.

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

Relevant Subsistence Uses

    The disturbance and potential displacement of marine mammals by 
sounds from 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. 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).
(1) Bowhead Whales
    Sound energy and general activity associated with drilling and 
operation of vessels and aircraft have the potential to temporarily 
affect the behavior of bowhead whales. Monitoring studies (Davis 1987, 
Brewer et al. 1993, Hall et al. 1994) have documented temporary 
diversions in the swim path of migrating bowheads near drill sites; 
however, the whales have generally been observed to resume their 
initial migratory route within a distance of 6-20 mi (10-32 km). 
Drilling noise has not been shown to block or impede migration even in 
narrow ice leads (Davis 1987, Richardson et al. 1991).
    Behavioral effects on bowhead whales from sound energy produced by 
drilling, such as avoidance, deflection, and changes in surface/dive 
ratios, have generally been found to be limited to areas around the 
drill site that are ensonified to >160 dB re 1 [mu]Pa rms, although 
effects have infrequently been observed out as far as areas ensonified 
to 120 dB re 1 [mu]Pa rms. Ensonification by drilling to levels >120 dB 
re 1 [mu]Pa rms will be limited to areas within about 0.93 mi (1.5 km) 
of either drilling units during Shell's exploration drilling program. 
Shell's proposed drill sites are located more than 64 mi (103 km) from 
the Chukchi Sea coastline, whereas mapping of subsistence use areas 
indicates bowhead hunts are conducted within about 30 mi (48 km) of 
shore; there is therefore little or no opportunity for the proposed 
exploration drilling activities to affect bowhead hunts.
    Vessel traffic along planned travel corridors between the drill 
sites and marine support facilities in Barrow and Wainwright would 
traverse some areas used during bowhead harvests by Chukchi villages. 
Bowhead hunts by residents of Wainwright, Point Hope and Point Lay take 
place almost exclusively in the spring prior to the date on which Shell 
would commence the proposed exploration drilling program. From 1984 
through 2009, all bowhead harvests by these Chukchi Sea villages 
occurred only between April 14 and June 24 (George and Tarpley 1986; 
George et al. 1987, 1988, 1990, 1992, 1995, 1998, 1999, 2000; Philo et 
al. 1994; Suydam et al. 1995, 1996, 1997, 2001, 2002, 2003, 2004, 2005, 
2006, 2007, 2008, 2009, 2010), and Shell will not enter the Chukchi Sea 
prior to July 1. However, fall whaling by some of these Chukchi Sea 
villages has occurred since 2010 and is likely to occur in the future, 
particularly if bowhead quotas are not completely filled during the 
spring hunt, and fall weather is accommodating. A Wainwright whaling 
crew harvested the first fall bowhead for these villages in 90 years or 
more on October 7, 2010, and another in October of 2011 (Suydam et al. 
2011, 2012, 2013). No bowhead whales were harvested during fall in 
2012, but 3 were harvested by Wainwright in fall 2013.
    Barrow crews have traditionally hunted bowheads during both spring 
and fall; however spring whaling by Barrow crews is normally finished 
before the date on which Shell operations would commence. From 1984 
through 2011 whales were harvested in the spring by Barrow crews only 
between April 23 and June 15 (George and Tarpley 1986; George et al. 
1987, 1988, 1990, 1992, 1995, 1998, 1999, 2000; Philo et al. 1994; 
Suydam et al. 1995, 1996, 1997, 2001, 2002, 2003, 2004, 2005, 2006, 
2007, 2008, 2009, 2010, 2011, 2012, 2103). Fall whaling by Barrow crews 
does take place during the time period when vessels associated with 
Shell's exploration drilling program would be in the Chukchi Sea. From 
1984 through 2011, whales were harvested in the fall by Barrow crews 
between August 31 and October 30, indicating that there is potential 
for vessel traffic to affect these hunts. Most fall whaling by Barrow 
crews, however, takes place east of Barrow along the Beaufort Sea 
coast, therefore providing little opportunity for vessel traffic 
associated with Shell's exploration drilling program to affect them. 
For example, Suydam et al. (2008) reported that in the previous 35 
years, Barrow whaling crews harvested almost all their whales in the 
Beaufort Sea to the east of Point Barrow. Shell's mitigation measures, 
which include a system of Subsistence Advisors (SAs), Community 
Liaisons, and Com Centers, will be implemented to avoid any effects 
from vessel traffic on fall whaling in the Chukchi Sea by Barrow and 
Wainwright.
    Aircraft traffic (helicopters and small fixed wing airplanes) 
between the drill sites and facilities in Wainwright and Barrow would 
also traverse these subsistence areas. Flights between the drill sites 
and Wainwright or other shoreline locations would take place after the 
date on which spring bowhead whaling out of Point Hope, Point Lay, and 
Wainwright is typically finished for the year; however, Wainwright has 
harvested bowheads in the fall since 2010 and aircraft may traverse 
areas sometimes utilized for these fall hunts. Aircraft overflights 
between the drill sites and Barrow or other shoreline locations could 
also occur over areas used by Barrow crews during fall whaling, but 
again, most fall whaling by Barrow crews takes place to the east of 
Barrow in the Beaufort Sea. The most commonly observed reactions of 
bowheads to aircraft traffic are hasty dives, but changes in 
orientation, dispersal, and changes in activity are sometimes noted. 
Such reactions could potentially affect subsistence hunts if the 
flights occurred near and at the same time as the hunt, but Shell has 
developed and proposes to implement a number of mitigation measures to 
avoid such impacts. These mitigation measures include minimum flight 
altitudes, employment of SAs, and Com Centers. Twice-daily calls are 
held during the exploration drilling program and are attended by 
operations staff, logistics staff, and SAs. Vessel movements and 
aircraft flights are adjusted as needed and planned in a manner that 
avoids potential impacts to

[[Page 35778]]

bowhead whale hunts and other subsistence activities.
(2) Beluga Whale
    Beluga whales typically do not represent a large proportion of the 
subsistence harvests by weight in the communities of Wainwright and 
Barrow, the nearest communities to Shell's planned exploration drilling 
program. Barrow residents hunt beluga in the spring (normally after the 
bowhead hunt) in leads between Point Barrow and Skull Cliffs in the 
Chukchi Sea, primarily in April-June and later in the summer (July-
August) on both sides of the barrier island in Elson Lagoon/Beaufort 
Sea (Minerals Management Service [MMS] 2008), but harvest rates 
indicate 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.
    Belugas typically represent a much greater proportion of the 
subsistence harvest in Point Lay and Point Hope. Point Lay's primary 
beluga hunt occurs from mid-June through mid-July, but can sometimes 
continue into August if early success is not sufficient. 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. 
Shell's proposed drill sites are located more than 60 mi (97 km) 
offshore, therefore proposed exploration drilling in the Burger 
Prospect would have no or minimal impacts on beluga hunts. 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. However, all of the beluga 
hunt by Barrow residents in the Chukchi Sea, and much of the hunt by 
Wainwright residents, would likely be completed before Shell activities 
commence. Additionally, vessel and aircraft traffic associated with 
Shell's planned exploration 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 vessel and 
aircraft traffic corridors do not traverse areas indicated in recent 
mapping as utilized by Point Lay or Point Hope for beluga hunts, and 
avoids important beluga hunting areas in Kasegaluk Lagoon that are used 
by Wainwright. Shell has developed a number of mitigation measures, 
e.g., PSOs on board vessels, minimum flight altitudes, and the SA and 
Com Center programs, to ensure that there is no impact on the 
availability of the beluga whale as a subsistence resource.
(3) Pinnipeds
    Seals are an important subsistence resource and ringed seals make 
up the bulk of the seal harvest. Most ringed and bearded seals are 
harvested in the winter or in the spring before Shell's exploration 
drilling program would commence, but some harvest continues during open 
water and could possibly be affected by Shell's planned activities. 
Spotted seals are also harvested during the summer. Most seals are 
harvested in coastal waters, with available maps of recent and past 
subsistence use areas indicating seal harvests have occurred only 
within 30-40 mi (48-64 km) of the coastline. Shell's planned drill 
sites are located more than 64 statute mi (103 km) offshore, so 
activities within the Burger Prospect, such as drilling, would have no 
impact on subsistence hunting for seals. Helicopter traffic between 
land and the offshore exploration drilling operations could potentially 
disturb seals and, therefore, subsistence hunts for seals, but any such 
effects would be minor and temporary lasting only minutes after the 
flight has passed due to the small number of flights and the altitude 
at which they typically fly, and the fact that most seal hunting is 
done during the winter and spring when the exploration drilling program 
is not operational. Mitigation measures to be implemented by Shell 
include minimum flight altitudes, employment of subsistence advisors in 
the villages, and operation of Com Centers.

Potential Impacts to Subsistence Uses

    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 
as: An impact resulting from the specified activity: (1) That is likely 
to reduce the availability of the species to a level insufficient for a 
harvest to meet subsistence needs by: (i) Causing the marine mammals to 
abandon or avoid hunting areas; (ii) Directly displacing subsistence 
users; or (iii) Placing physical barriers between the marine mammals 
and the subsistence hunters; and (2) That cannot be sufficiently 
mitigated by other measures to increase the availability of marine 
mammals to allow subsistence needs to be met.
    Noise and general activity during Shell's proposed 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 in this document) is avoidance of the 
ensonified area. In the case of bowhead whales, this often means that 
the animals divert from their normal migratory path by several 
kilometers. 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, Native Alaskans 
report that bowheads exhibit angry behaviors in the presence of seismic 
activity, such as tail-slapping, which translates to danger for nearby 
subsistence harvesters. However, only limited seismic activity is 
planned in the vicinity of the drill units in 2015.

Plan of Cooperation or Measures To Minimize Impacts to Subsistence 
Hunts

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a Plan of 
Cooperation (POC) or information that identifies what measures have 
been taken and/or will be taken to minimize adverse effects on the 
availability of marine mammals for subsistence purposes.
    Shell prepared and will implement a POC under the MMPA, which 
requires that all exploration operations be conducted in a manner that 
prevents unreasonable conflicts between oil and gas activities and the 
subsistence activities and resources of residents of the North Slope. 
This stipulation also requires adherence to USFWS and NMFS regulations, 
which require an operator to implement a POC to mitigate the potential 
for conflicts between the proposed activity and traditional subsistence 
activities (50 CFR 18.124(c)(4) and 50 CFR 216.104(a)(12)). A POC was 
prepared and submitted with the initial Chukchi Sea EP that was 
submitted to BOEM in May 2009, and approved on 7 December 2009. 
Subsequent POC Addendums were submitted in May 2011 with a revised 
Chukchi Sea EP and the IHA application for the 2012 exploration 
drilling

[[Page 35779]]

program. For this IHA application, Shell again updated the POC 
Addendum. The POC Addendum was updated to include documentation of 
meetings undertaken to specifically gather feedback from stakeholder 
communities on Shell's implementation of the Chukchi Sea exploration 
drilling program during 2012, plus inform and obtain their input 
regarding the continuation of the program with the addition of a second 
drilling unit, additional vessels and aircraft.
    The POC Addendum identifies the measures that Shell has developed 
in consultation with North Slope subsistence communities to minimize 
any adverse effects on the availability of marine mammals for 
subsistence uses and will implement during its planned Chukchi Sea 
exploration drilling program for the summer of 2015. In addition, the 
POC Addendum details Shell's communications and consultations with 
local subsistence communities concerning its planned exploration 
drilling program, potential conflicts with subsistence activities, and 
means of resolving any such conflicts (50 CFR 18.128(d) and 50 CFR 
216.104(a)(12)(i), (ii), (iv)). Shell has documented its contacts with 
the North Slope subsistence communities, as well as the substance of 
its communications with subsistence stakeholder groups.
    The POC Addendum report (Attachment C of the IHA application) 
provides a list of public meetings attended by Shell since 2012 to 
develop the POC and the POC Addendum. The POC Addendum will be updated 
through July 2015, and includes sign-in sheets and presentation 
materials used at the POC meetings held in 2014 to present the 2015 
Chukchi Sea exploration drilling information. Comment analysis tables 
for numerous meetings held during 2014 summarize feedback from the 
communities on Shell's 2015 exploration drilling and planned activities 
beginning in the summer of 2015. All comments from the communities were 
addressed in Shell's final POC.
    The following mitigation measures, plans and programs, are integral 
to this POC and were developed during Shell's consultation with 
potentially affected subsistence groups and communities. These 
measures, plans, and programs to monitor and mitigate potential impacts 
to subsistence users and resources will be implemented by Shell during 
its exploration drilling operations in the Chukchi Sea. The mitigation 
measures Shell has adopted and will implement during its Chukchi Sea 
exploration drilling operations are listed and discussed below. These 
mitigation measures reflect Shell's experience conducting exploration 
activities in the Alaska Arctic OCS since the 1980s and its ongoing 
efforts to engage with local subsistence communities to better 
understand their concerns and develop appropriate and effective 
mitigation measures to address those concerns. This most recent version 
of Shell's planned mitigation measures was presented to community 
leaders and subsistence user groups starting in January 2009 and has 
evolved since in response to information learned during the 
consultation process.
    To minimize any cultural or resource impacts from its exploration 
operations, Shell will continue to 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 hunt:
(1) Communications
     Shell has developed a Communication Plan and will 
implement this plan before initiating exploration drilling operations 
to coordinate activities with local subsistence users, as well as 
Village Whaling Captains' Associations, to minimize the risk of 
interfering with subsistence hunting activities, and keep current as to 
the timing and status of the bowhead whale hunt and other subsistence 
hunts. The Communication Plan includes procedures for coordination with 
Com Centers to be located in coastal villages along the Chukchi Sea 
during Shell's proposed exploration drilling activities.
     Shell will employ local SAs from the Chukchi Sea villages 
that are potentially impacted by Shell's exploration drilling 
activities. The SAs will provide consultation and guidance regarding 
the whale migration and subsistence activities. There will be one per 
village, working approximately 8-hr per day and 40-hr per week during 
each drilling season. The subsistence advisor will use local knowledge 
(Traditional Knowledge) to gather data on subsistence lifestyle within 
the community and provide advice on ways to minimize and mitigate 
potential negative impacts to subsistence resources during each 
drilling season. Responsibilities include reporting any subsistence 
concerns or conflicts; coordinating with subsistence users; reporting 
subsistence-related comments, concerns, and information; coordinating 
with the Com and Call Center personnel; and advising how to avoid 
subsistence conflicts.
(2) Aircraft Travel
     Aircraft over land or sea shall not operate below 1,500 ft 
(457 m) altitude unless engaged in marine mammal monitoring, 
approaching, landing or taking off, in poor weather (fog or low 
ceilings), or in an emergency situation.
     Aircraft engaged in marine mammal monitoring shall not 
operate below 1,500 ft (457 m) in areas of active whaling; such areas 
to be identified through communications with the Com Centers.
(3) Vessel Travel
     The drilling unit(s) and support vessels will enter the 
Chukchi Sea through the Bering Strait on or after 1 July, minimizing 
effects on marine mammals and birds that frequent open leads and 
minimizing effects on spring and early summer bowhead whale hunting.
     The transit route for the drilling unit(s) and drilling 
support fleets will avoid known fragile ecosystems and the Ledyard Bay 
Critical Habitat Unit (LBCHU) (for spectacled eiders), and will include 
coordination through Com Centers.
     PSOs will be aboard the drilling unit(s) and transiting 
support vessels.
     When within 900 ft (274 m) of whales, vessels will reduce 
speed, avoid separating members from a group and avoid multiple changes 
of direction.
     Vessel speed will be reduced during inclement weather 
conditions in order to avoid collisions with marine mammals.
     Shell will communicate and coordinate with the Com Centers 
regarding all vessel transit.
(4) ZVSP
     Airgun arrays will be ramped up slowly during ZVSPs to 
warn cetaceans and pinnipeds in the vicinity of the airguns and provide 
time for them to leave the area and avoid potential injury or 
impairment of their hearing abilities. Ramp ups from a cold start when 
no airguns have been firing will begin by firing a single airgun in the 
array. A ramp up to the required airgun array volume will not begin 
until there has been a minimum of 30 min of observation of the safety 
zone by PSOs to assure that no marine mammals are present. The safety 
zone is the extent of the 180 dB radius for cetaceans and 190 dB re 1 
[mu]Pa rms for pinnipeds. The entire safety zone must be visible during 
the 30-min lead-into an array ramp up. If a marine mammal(s) is sighted 
within the safety zone during the 30-min watch prior to ramp up, ramp 
up will be delayed until the marine mammal(s) is

[[Page 35780]]

sighted outside of the safety zone or the animal(s) is not sighted for 
at least 15-30 min: 15 min for small odontocetes and pinnipeds, or 30 
min for baleen whales and large odontocetes.
(5) Ice Management
     Real time ice and weather forecasting will be from SIWAC.
(6) Oil Spill Response
     Pre-booming is required for all fuel transfers between 
vessels.
    The potentially affected subsistence communities, identified in 
BOEM Lease Sale, that were consulted regarding Shell's exploration 
drilling activities include: Barrow, Wainwright, Point Lay Point Hope, 
Kotzebue, and Deering. Additionally, Shell has met with subsistence 
groups including the Alaska Eskimo Whaling Commission (AEWC), Inupiat 
Community of the Arctic Slope (ICAS), and the Native Village of Barrow, 
and presented information regarding the proposed activities to the 
North Slope Borough (NSB) and Northwest Arctic Borough (NWAB) 
Assemblies, and NSB and NWAB Planning Commissions during 2014. In July 
2014, Shell conducted POC meetings in Chukchi villages to present 
information on the proposed 2015 drilling season. Shell supplemented 
the IHA application with a POC addendum to incorporate these POC 
visits. Throughout 2014 and 2015 Shell anticipates continued engagement 
with the marine mammal commissions and committees active in the 
subsistence harvests and marine mammal research.
    Shell continues to meet each year with the commissioners and 
committee heads of AEWC, Alaska Beluga Whale Committee, the Nanuuq 
Commission, Eskimo Walrus Commission, and Ice Seal Committee jointly in 
co-management meetings. Shell held individual consultation meetings 
with representatives from the various marine mammal commissions to 
discuss the planned Chukchi exploration drilling program. Following the 
drilling season, Shell will have a post-season co-management meeting 
with the commissioners and committee heads to discuss results of 
mitigation measures and outcomes of the preceding season. The goal of 
the post-season meeting is to build upon the knowledge base, discuss 
successful or unsuccessful outcomes of mitigation measures, and 
possibly refine plans or mitigation measures if necessary.
    Shell attended the 2012-2014 Conflict Avoidance Agreement (CAA) 
negotiation meetings in support of exploration drilling, offshore 
surveys, and future drilling plans. Shell will do the same for the 
upcoming 2015 exploration drilling program. Finally, Shell signed the 
CAA in April 2015.

Unmitigable Adverse Impact Analysis and Determination

    NMFS considers that these mitigation measures including measures to 
reduce overall impacts to marine mammals in the vicinity of the 
proposed exploration drilling area and measures to mitigate any 
potential adverse effects on subsistence use of marine mammals are 
adequate to ensure subsistence use of marine mammals in the vicinity of 
Shell's proposed exploration drilling program in the Chukchi Sea.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the mitigation and monitoring 
measures, NMFS has determined that there will not be an unmitigable 
adverse impact on the availability of marine mammals for taking for 
subsistence uses from Shell's proposed activities.

Endangered Species Act (ESA)

    There are four marine mammal species listed under the ESA with 
confirmed or possible occurrence in the proposed project area: the 
bowhead, humpback, and fin whales, and ringed seals. NMFS' Permits and 
Conservation Division initiated consultation with NMFS Alaska Regional 
Office (AKRO) 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 June 
2015, NMFS finished conducting its section 7 consultation and issued a 
Biological Opinion, and concluded that the issuance of the IHA 
associated with Shell's 2015 Chukchi Sea drilling program is not likely 
to jeopardize the continued existence of the endangered bowhead, 
humpback, and fin whale, and the threatened Arctic sub-species of 
ringed 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 exploration drilling 
program in the Chukchi Sea, Alaska. NMFS has finalized the EA and 
prepared a Finding of No Significant Impact for this action. Therefore, 
preparation of an Environmental Impact Statement is not necessary. 
NMFS' draft 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 exploration drilling program in the Chukchi 
Sea during the 2015 open-water season, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated.

    Dated: June 15, 2015.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2015-15013 Filed 6-19-15; 8:45 am]
 BILLING CODE 3510-22-P