[Federal Register Volume 76, Number 149 (Wednesday, August 3, 2011)]
[Notices]
[Pages 46729-46753]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-19663]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XA396
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Shallow Hazards Survey in the
Chukchi Sea, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental take authorization.
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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA)
regulations, notification is hereby given that NMFS has issued an
Incidental Harassment Authorization (IHA) to Statoil USA E&P Inc.
(Statoil) to take, by harassment, small numbers of 13 species of marine
mammals incidental to shallow hazards and geotechnical surveys in the
Chukchi Sea, Alaska, during the 2011 Arctic open-water season.
DATES: Effective August 1, 2011, through November 30, 2011.
ADDRESSES: Inquiry for information on the incidental take authorization
should be addressed to P. Michael Payne, Chief, Permits, Conservation
and Education Division, Office of Protected Resources, National Marine
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910. A
copy of the application containing a list of the references used in
this document, NMFS' 2010 Environmental Assessment (EA), 2011
Supplemental Environmental Assessment (SEA), Finding of No Significant
Impact (FONSI), and the IHA may be obtained by writing to the address
specified above, telephoning the contact listed below (see FOR FURTHER
INFORMATION CONTACT), or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Documents cited in this notice may be viewed, by appointment,
during regular business hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected
Resources, NMFS, (301) 427-8401 or Brad Smith, NMFS, Alaska Region,
(907) 271-3023.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce (Secretary) to allow, upon request,
the incidental, but not intentional taking 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 regulations are issued or, if the taking is limited to
harassment, a notice of a proposed authorization is provided to the
public for review.
Authorization 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 taking are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as:
An impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the U.S. can apply for an authorization to
incidentally take small numbers of marine mammals by harassment. Except
with respect to certain activities not pertinent here, the MMPA defines
``harassment'' as:
Any act of pursuit, torment, or annoyance which (i) has the
potential to injure a marine mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has the potential to disturb a
marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to,
migration, breathing, nursing, breeding, feeding, or sheltering
[Level B harassment].
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS
review of an application followed by a 30-day public notice and comment
period on any proposed authorizations for the incidental harassment of
marine mammals. Within 45 days of the close of the comment period, NMFS
must either issue or deny issuance of the authorization.
Summary of Request
NMFS received an application on March 1, 2011, from Statoil for the
taking, by harassment, of marine mammals incidental to shallow hazards
site surveys and soil investigations (geotechnical boreholes) in the
Chukchi Sea, Alaska, during the 2011 open-water season. After
addressing comments from NMFS, Statoil modified its application and
submitted a revised application on April 19, 2011. The April 19, 2011,
application was the one available for public comment (see ADDRESSES)
and considered by NMFS for the IHA.
The shallow hazards and site clearance surveys would use a towed
airgun cluster consisting of four, 10-in\3\ airguns with a ~600 m
(1,969 ft) towed hydrophone streamer, as well as additional lower-
powered and higher frequency survey equipment for collecting
bathymetric and shallow sub-bottom data. The proposed survey will take
place on and near Statoil's leases in the Chukchi Sea, covering a total
area of ~665 km\2\ located ~240 km (150 mi) west of Barrow and ~165 km
(103 mi) northwest of Wainwright, in water depths of ~30-50 m (100-165
ft).
The geotechnical soil investigations will take place at prospective
drilling locations on Statoil's leases and leases jointly owned with
ConocoPhillips Alaska Inc. (CPAI). All cores will be either 5.3 cm or
7.1 cm (2.1 in. or 2.8 in.) in diameter (depending on soil
[[Page 46730]]
type), and those collected at prospective drilling locations will be up
to 100 m (328 ft) in depth. The maximum total number of samples
collected as part of the drilling location and site survey program will
be ~29.
Statoil intends to conduct these marine surveys during the 2011
Arctic open-water season (July through November). Impacts to marine
mammals may occur from noise produced from active acoustic sources
(including airguns) used in the surveys.
Description of the Specified Activity
Statoil acquired 16 leases in the Chukchi Sea during Lease Sale 193
held in February 2008. The leased areas are located ~240 km (150 mi)
west of Barrow and ~160 km (~100 mi) northwest of Wainwright. During
the open-water season of 2010, Statoil conducted a 3D seismic survey
over its lease holdings and the surrounding area. The data gathered
during that survey are currently being analyzed in order to determine
potential well locations on the leases. These analyses will be
completed prior to commencement of the site survey program. During the
open-water season of 2011, Statoil proposes to conduct shallow hazards
and site clearance surveys (site surveys) and soil investigations
(geotechnical boreholes).
The operations will be performed from two different vessels.
Shallow hazards surveys will be conducted from the M/V DUKE, while
geotechnical soil investigations will be conducted from the M/V FUGRO
SYNERGY (see Statoil's application for vessel specifications). Both
vessels will mobilize from Dutch Harbor in late July and arrive in the
Chukchi Sea to begin work on or after August 1. Allowing for poor
weather days, operations are expected to continue into late September
or early October. However, if weather permits and all planned
activities have not been completed, operations may continue as late as
November 15.
The site survey work on Statoil's leases will require approximately
23 days to complete. Geotechnical soil investigations on Statoil leases
and on leases jointly held with CPAI will require ~14 days of
operations.
Shallow Hazards and Site Clearance Surveys
Shallow hazards site surveys are designed to collect bathymetric
and shallow sub-seafloor data that allow the evaluation of potential
shallow faults, gas zones, and archeological features at prospective
exploration drilling locations, as required by the Bureau of Ocean
Energy Management, Regulation and Enforcement (BOEMRE). Data are
typically collected using multiple types of acoustic equipment. During
the site surveys, Statoil proposes to use the following acoustic
sources: 4 x 10 in\3\ airgun cluster, single 10 in\3\ airgun, Kongsberg
SBP3000 sub-bottom profiler, GeoAcoustics 160D side-scan sonar, and a
Kongsberg EM2040 multi-beam echosounder. The acoustic characteristics
(including operating frequencies and estimated source levels) of all
active sources are described in the Federal Register notice for the
proposed IHA (76 FR 30110; May 24, 2011). That information has not
changed and is therefore not repeated here.
Geotechnical Soil Investigations
Geotechnical soil investigations are performed to collect detailed
data on seafloor sediments and geological structure to a maximum depth
of 100 m (328 ft). These data are then evaluated to help determine the
suitability of the site as a drilling location. Statoil has contracted
with Fugro who will use the vessel M/V FUGRO SYNERGY to complete the
planned soil investigations. Three to four bore holes will be collected
at each of up to 5 prospective drilling locations on Statoil's leases,
and up to 3 boreholes may be completed at each of up to 3 potential
drilling locations on leases jointly owned with CPAI. This would result
in a maximum total of 29 bore holes to be completed as part of the
geotechnical soil investigation program. The FUGRO SYNERGY operates a
Kongsberg EA600 Echosounder and uses a Kongsberg 500 high precision
acoustic positioning (HiPAP) system for precise vessel positioning
while completing the boreholes. The acoustic characteristics (including
operating frequencies and estimated source levels) of all active
sources, as well as the sounds produced during soil investigation
sampling, are described in the Federal Register notice for the proposed
IHA (76 FR 30110; May 24, 2011). That information has not changed and
is therefore not repeated here.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to Statoil published in
the Federal Register on May 24, 2011 (76 FR 30110). That notice
described, in detail, Statoil's proposed activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals and the availability of marine mammals for
subsistence uses. During the 30-day public comment period, NMFS
received three comment letters from the following: The Marine Mammal
Commission (Commission); the Alaska Eskimo Whaling Commission (AEWC);
and Alaska Wilderness League (AWL), Center for Biological Diversity,
Defenders of Wildlife, Earthjustice, Natural Resources Defense Council,
Oceana, Pacific Environment, and Sierra Club (collectively ``AWL'').
The AEWC submitted a copy of the 2011 Conflict Avoidance Agreement
(CAA), since Statoil declined to sign the CAA.
Any comments specific to Statoil's application that address the
statutory and regulatory requirements or findings NMFS must make to
issue an IHA are addressed in this section of the Federal Register
notice.
MMPA Concerns
Comment 1: AEWC states that Statoil's IHA application NMFS released
is incomplete because it did not contain a copy of the Plan of
Cooperation (POC). AEWC points out that Statoil stated that it ``is
developing a Plan of Cooperation (POC) for their proposed 2011
activities.'' (Statoil IHA Application at page 51), and since Statoil
did not provide the POC or any detail on the measures to be adopted in
compliance with 50 CFR 216.104(a)(12)(iii), NMFS cannot make the
determination required under the MMPA. AEWC further points out that
NMFS has previously stated that ``[i]t should be understood that the
POC is required by NMFS's implementing regulations to be submitted as
part of the industry's IHA application'' (74 FR 55368, 55393; October
27, 2009). AEWC requests that NMFS enforce the requirement that Statoil
set forth, in its application, the proposed measures employed to
prevent conflicts with subsistence activities.
Response: Although NMFS agrees with AEWC's statement that a POC is
essential for making the determination for granting an IHA to the
industry, it is not used to determine the completeness of an IHA
application. A complete IHA application should address all fourteen
questions in NMFS' marine mammal incidental take application
guidelines, which can be found at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#apply. Concerning the POC, as stated in item 12 of the
application guideline, the applicant ``must submit either a `plan of
cooperation' or information that identifies what measures have been
taken and/or will be taken to minimize any adverse effects on the
availability of marine mammals for subsistence uses.'' In the case of
Statoil's IHA application, NMFS believes that the company provided
detailed information that identified what measures have been
[[Page 46731]]
taken and will be taken to minimize any adverse effects to subsistence
harvesting of marine mammals, such as maintaining an open and
transparent process with all stakeholders throughout the duration of
its activities in the Chukchi Sea, identifying transit routes and
timing to avoid other subsistence use areas and communicating with
coastal communities before operating in or passing through these areas.
In addition, Statoil completed the early phase of the POC process for
the proposed project by meeting with the North Slope Borough Department
of Wildlife Management (December 2010) and the AEWC (mini-convention in
Barrow, February 2011), and arranged to visit and hold public meetings
in the affected Chukchi Sea villages, including Pt. Hope, Pt. Lay,
Wainwright, and Barrow during the week of March 21, 2011. NMFS
determined that these activities showed that Statoil was in the process
of finalizing its POC with the Native communities, therefore NMFS
determined that Statoil's application was complete. Subsequently on
June 20, 2011, NMFS received a draft POC with detailed information on
the POC process. On July 14, 2011, NMFS received the final POC from
Statoil.
Impacts to Marine Mammals
Comment 2: AWL states that NMFS's uniform marine mammal harassment
threshold for impulsive sounds does not take into account the
documented reactions of specific species found in the Arctic to much
lower received levels. The AWL argues by providing an example that
harbor porpoises have been shown to be exceptionally sensitive to
noise, and NMFS has used 120 dB as the appropriate threshold when
authorizing marine mammal take for Navy sonar activities. In addition,
the AWL states, by referring to Southall et al. (2007), that ``a 2007
study found that for migrating bowheads `the onset of significant
behavioral disturbance from multiple pulses occurred at [received
levels] around 120 dB re: 1 [mu]Pa[.]' ''. The AWL concludes that ``the
2007 study in fact determined that the reactions of migrating bowhead
whales to sounds as low as 120 dB had a `higher potential' for
affecting foraging, reproduction, or survival rates.''
Response: NMFS does not agree with AWL's assessment on acoustic
effects of marine mammals. The 120 dB threshold for the onset of
behavioral harassment for harbor porpoise by Navy sonar activities is
limited to exposure to mid- and high-frequency sonar signals, which are
defined as sound with dominant frequency at 1-10 kHz and above 10 kHz,
respectively. This is because harbor porpoise is considered a ``high
frequency cetacean'' (Southall et al. 2007), and, therefore, is more
sensitive to noise exposure at higher frequency spectra. Sounds
produced during marine seismic surveys have most of their energy
concentrated at the lower end of the frequency spectra, which is
largely outside of the harbor porpoises' hearing threshold (Andersen
1970; Kastelein et al. 2002). Therefore, NMFS believes that it is
scientifically justifiable to use received level at 120 dB as the
threshold for behavioral harassment for harbor porpoises exposed to
mid- and high-frequency Navy sonar, but it is not appropriate to use
this received level as the threshold for behavioral harassment when
exposed to seismic sounds.
Regarding its comment on bowhead disturbances when exposed to
seismic sound at received level of 120 dB, AWL incorrectly cited the
reference in Southall et al. (2007) as ``a 2007 study.'' In fact, the
reference in Southall et al. (2007) that AWL refers to was a conference
abstract presented at the 1999 Meeting of the Acoustical Society of
America by Richardson et al. (1999) titled ``Displacement of Migrating
Bowhead Whales by Sounds from Seismic Surveys in Shallow Waters of the
Beaufort Sea.'' The study was conducted in the summer months between
1996 and 1998 in shallow waters of the Beaufort Sea, Alaska, during
seismic surveys with 6-16 airguns and total volumes of 560-1,500 in\3\.
As stated in the abstract, ``[w]estward autumn migration of bowhead
whales near and offshore of the exploration area was monitored by
aerial surveys flown daily, weather permitting, during the three
seasons. Aerial survey data from days with and without airgun
operations were compared.'' The authors observed that ``[m]ost bowheads
avoided the area within 20 km of the operating airguns; bowheads were
common there on days without airgun operations.'' In addition, the
authors stated that bowhead whale ``sighting rates just beyond the
avoidance zone were higher on days with airgun operations. Broadband
received levels of airgun pulses at 20 km were typically 120-130 dB re:
1 [micro]Pa (rms over pulse duration).'' Based on this description,
NMFS concludes that the displacement of bowhead whales by seismic
surveys constitutes temporary avoidance behavior during ``days with
airgun operations,'' and these whales seem to avoid an area where
received levels were about 120-130 dB. The authors did not state that
they observed ``significant behavioral disturbance,'' nor did they
report a disruption of behavioral patterns, either of which could be an
indication of Level B harassment.
In addition, these minor course changes occurred during migration
and have not been seen at other times of the year and during other
activities. Therefore, NMFS does not believe that minor course
corrections during a migration equate to ``take'' under the MMPA. This
conclusion is based on controlled exposure experiments conducted on
migrating gray whales exposed to the U.S. Navy's low frequency sonar
(LFA) sources (Tyack 2009). When the source was placed in the middle of
the migratory corridor, the whales were observed deflecting around the
source during their migration. However, such minor deflection is
considered not to be biologically significant. To show the contextual
nature of this minor behavioral modification, recent monitoring studies
of Canadian seismic operations indicate that when, not migrating, but
involved in feeding, bowhead whales do not move away from a noise
source at an SPL of 160 dB. Therefore, while bowheads may avoid an area
of 20 km (12.4 mi) around a noise source, when that determination
requires a post-survey computer analysis to find that bowheads have
made a 1 or 2 degree course change, NMFS believes that does not rise to
the level of a ``take.'' NMFS therefore continues to estimate
``takings'' under the MMPA from impulse noises, such as seismic, as
being at a distance of 160 dB (re 1 [micro]Pa) from the source.
Although it is possible that marine mammals could react to any sound
levels detectable above the ambient noise level within the animals'
respective frequency response range, this does not mean that such
animals would react in a biologically significant way.
Therefore, unless and until an improved approach is developed and
peer-reviewed, NMFS will continue to use the 160-dB threshold for
determining the level of take of marine mammals by Level B harassment
for impulse noise (such as from airguns).
Comment 3: In reference to the impact analysis NMFS provided in the
Federal Register notice for the proposed IHA (76 FR 30110; May 24,
2011), AWL states that the existing science does not support strictly
distinguishing impulse and non-impulse noise, and that NMFS recognizes
that over long distances (tens of kilometers), impulse sounds can
become ``stretched'' out. Further, AWL refers to the peer-review panel
report for this year's Open Water Meeting noting
[[Page 46732]]
that phenomenon and concluding that sounds from airguns ``should not be
treated as truly impulsive when received at ranges where sound
propagation is known to remove the impulsive nature of these signals.''
AWL concludes that ``a uniform 160-dB harassment threshold is not
justified by either the science or the standards imposed by the MMPA.
And, without an appropriate threshold, NMFS cannot begin to accurately
gauge the extent of marine mammal take from Statoil's operations.''
Response: Although NMFS agrees with AWL that at long distances an
impulse acoustic signal will lose its pulse feature by stretching its
duration due to multipath propagation, these signals (or noises) are
still fundamentally different from other non-impulse noise sources such
as those from vibratory pile driving, drilling, and dredging based on
the following characteristics:
First, the elongated pulse signals from the airgun array at far
distances are caused by multipath propagation in a reverberant
environment (Greene and Richardson 1988; Richardson et al. 1995; Madsen
et al. 2002; Lurton 2002), which is different from other non-pulse
signals at closer distances, which is composed of mostly direct sound.
The reverberation part of the sound in the ocean behaves differently
compared to the direct sound and early surface and bottom reflections
from the perspective of the receiver. The direct sound and early
reflections follow the inverse square law, with the addition of
absorption effects in the case of early reflections, and so their
amplitude varies with distance. However the reverberant part of the
sound remains relatively constant up to a large distance with the
position of the receiver. Therefore, as distance increases from the
source, the component of reverberant sounds increases against the
direct sound. In addition, the reverberant energy is less directional
and is distributed more uniformly around the ambient environment of the
animal. As shown in human psychoacoustics, these characteristics in a
reverberant field provide distance cues to the listener as to how far
away the source is located (Howard and Angus 2006). Therefore, at a
distance where the airgun signals have been ``stretched'' to non-pulse,
the receiving animals would be able to correctly perceive that these
sounds are coming from far away, and would thus be less likely to be
affected behaviorally as behavior responses are not solely dependent on
received levels. Other factors such as distance to the source, movement
of the source, source characteristics, and the receiver's (i.e.,
animal's) age, sex, motivation states, and prior experience, etc.
probably play more significant roles in determining the responses of
the animals that are being exposed to lower levels of noises than
solely the received sound level.
Second, even though during horizontal propagation, the initial
short pulse could be ``stretched'' from milliseconds when emitted to
about 0.25-0.5 second long at a few kilometers in shallow water
(Richardson et al. 1995), the noise duration is still very short when
compared to those ``conventional'' non-pulse noise sources (vibratory
pile driving, drilling, and dredging, etc.) for which NMFS applies a
120 dB threshold for assessing behavioral harassment. The empirical
measurements of a 3,000 in\3\ airgun array received signal
characteristics showed that its pulse duration was stretched to 0.2
second at approximately 1.3 km (0.8 mi), to 0.5 second at approximately
10 km (6.2 mi), and to about 1.8 seconds at 80 km (50 mi) from the
source (O'Neill et al. 2011). Based on the airgun array's firing rate
of 0.1 Hz (1 shot every 10 seconds), the duty cycle was only 18% for
the signal at 80 km (50 mi) (1.8 seconds on for every 10 seconds).
Conversely, the ``conventional'' non-pulse noises from vibratory pile
driving, drilling, and dredging typically last much longer (minutes to
hours) with very brief (seconds for vibratory pile driving) intervals.
Therefore, NMFS does not agree that it is appropriate to treat
elongated airgun pulses at long distances as a ``conventional'' non-
pulse signal and apply the 120 dB behavioral response threshold to that
sound source.
Comment 4: AWL states that NMFS' approach to determining take for
Statoil's surveying during the bowhead fall migration is not
supportable because the proposed authorization does not adequately take
into account that Statoil's fall surveying will take place within a
migratory corridor. AWL argues that ``by relying on density without
sufficiently considering the overlap of ensonified areas, it assumes
that migratory animals remain relatively stationary from one day to the
next, despite Statoil's operations exposing the same areas of the ocean
to elevated sound level at very different times, days or even weeks
apart.'' AWL further states that ``NMFS' calculations are premised on
the notion that a bowhead whale exposed, for example, on day 15 during
the course of the survey remains stationary and is the same whale
exposed when the vessel travels near the area again on day 23 during
the detailed survey, amounting to only a single harassed whale. Such a
result does not reflect the reality of whales moving through the
surveying area on their way to wintering grounds in the Bering Sea.''
AWL points out that ``in the past, NMFS has avoided this problem by
calculating the ensonified area based on the amount of linear surveying
line, rather than by extending the boundaries of the area to be
surveyed.''
Response: NMFS does not agree with AWL's statement that our take
estimates for bowhead whales during Statoil's shallow hazards survey in
the Chukchi Sea are ``not supportable.'' First, evidence has shown that
the bowhead whale fall migratory route through the Chukchi Sea is more
spread out than in the Beaufort Sea, where whales tend to have a more
confined migratory corridor due to ice conditions. In a recent
satellite tagging study, Quakenbush et al. (2010) concluded from GPS
data that bowhead whales do not spend much time in the north-central
Chukchi Sea, near Statoil's 2011 proposed shallow hazards survey.
Kernel densities from the study showed that areas with the highest
probability of bowhead use from September to December were near Point
Barrow and the northeast Chukotka coast; the area along the east coast
of Wrangel Island also had a moderate probability of use (Quakenbush et
al. 2010). In addition, movements and behavior of tagged bowhead whales
in this study indicated that the greatest potential for disturbance
from industrial activities is near Point Barrow in September and
October and in the lease area in September. Lastly, Statoil's shallow
hazards survey is scheduled to begin on August 1, 2011, and would
require approximately 23 days to complete. Therefore, there is the
potential for Statoil to complete their entire operation prior to the
time when bowhead whales typically begin entering the Chukchi Sea in
the fall (i.e., mid-September). Thus NMFS determined that the marine
mammal density data provided in Statoil's IHA application for this
period are overestimated. And to compensate for the overestimation due
to the lower than actual density, NMFS opted not to consider overlaps
of the ensonified area.
Additionally, it should be noted that this is not the first time
that this approach has been used in estimating takes from shallow
hazards and 3D seismic surveys. When airgun activity, as part of a
shallow hazards survey is ongoing continuously after ramping up, it is
expected that nearly all bowhead whales would avoid the areas
ensonified to >160 dB. This would
[[Page 46733]]
mean that migrating whales passing through the region would likely
avoid the immediate area around the activities, and thus not be
``taken'' repeatedly by exposure to sounds >160 dB.
Alternatively, bowhead take numbers can be calculated based on the
migratory animals' daily average multiplied by the duration in days
when seismic activities are ongoing, as was typically done to estimate
bowhead whale takes in the Beaufort Sea during their migration.
However, no such data are available for migratory bowheads in the
Chukchi Sea, therefore, this method cannot be applied.
Regarding the method NMFS used to estimate the take by calculating
the ensonified area based on the amount of linear surveying line,
rather than by extending the boundaries of the area to be surveyed,
this method is used for 2D seismic surveys where there is no
overlapping ensonified area. Using this methodology to calculate for
overlapping ensonified area would result in an unrealistically large
area (in some cases, it could be larger than the entire Chukchi Sea)
being treated as the affected area, which NMFS does not think is
appropriate.
Comment 5: AWL states that NMFS must include the effects from all
of Statoil's equipment, not only the noise from the airguns (surveying)
and ship thrusters (drilling). AWL points out that this year's peer-
review panel found that Statoil's other acoustic sources are
``relatively powerful and operate in the acoustic band of many if not
most marine mammals.'' AWL further states that although NMFS has
proposed that Statoil conduct field measurements for all its equipment
in order to determine whether additional safety zones are required,
this cannot cure the failure to accurately determine in advance the
number of marine mammals that may be harassed by Statoil's activities.
AWL states that NMFS should further consider the fact that Statoil's
two exploratory activities (surveying and drilling) may take place in
close proximity to one another, each using a variety of noise-producing
equipment that could contribute to adverse synergistic effects.
Response: NMFS agrees with AWL that all of Statoil's active
acoustic equipment must be included and analyzed for their potential
effects on marine mammals. In its Federal Register notice of proposed
IHA (76 FR 30110; May 24, 2011) and the SEA, NMFS provided a detailed
description and analysis of these active acoustic sources. A list of
these sources with their frequency bandwidth and modeled/known maximum
source level are provided in Table 1-3 of the SEA. These sources
include the Kongsberg EA600 echosounder, GeoAcoustics 160D side-scan
sonar, Kongsberg SBP300 sub-bottom profiler, Kongsberg EM2040 multibeam
echosounder, and Kongsberg HiPAP 500. All these active sources are
expected to have maximum source levels below those of the airgun array
except the GeoAcoustics 160D side-scan sonar, of which the maximum
source level is approximately 233 dB re 1 [mu]Pa @ 1m. However, since
this equipment operates at frequencies of 114 and 410 kHz, the modeled
isopleths drop down to 160 dB at about 453 and 108 m (1,486 and 354 ft)
from the source, and to 120 dB at about 1,177 and 221 m (3,861.5 and
725 ft) from the source for each of these two frequencies,
respectively, when high-frequency absorption is taken into
consideration. These distances are well within the modeled 160 dB and
120 dB zones for the airgun array, which is at 2,250 m and 39,000 m
(1.4 mi and 24 mi) for received levels of 160 and 120 dB, respectively.
Therefore, the acoustic footprints from all other active sources are
contained within that of the airgun array, and no additional take from
these sources is expected.
Nevertheless, as mentioned by AWL and described in detail in the
proposed IHA (76 FR 30110; May 24, 2011), Statoil will be required to
conduct sound source verification (SSV) tests for all acoustic
equipment used during the proposed shallow hazards survey. The
empirical measurements will further show the presence or absence of
low-frequency side-lobes and will be used to refine the exclusion
zones, which are required for implementing monitoring and mitigation
measures, as needed.
NMFS is aware of the relative locations of Statoil's two
exploratory activities (shallow hazards survey and geotechnical survey)
and has conducted appropriate analyses concerning sources and impacts
from both activities. These analyses are described in detail in the
proposed IHA (76 FR 30110; May 24, 2011) and the SEA. Please refer to
those documents for that discussion.
Mitigation Measures
Comment 6: AWL states that ``NMFS should consider a safety zone
specific to cow-calf pairs'' to provide additional protective measures
to address uncertainties regarding impacts on ``bowhead cow-calf pairs
and aggregations of whales.''
Response: Although it has been suggested that female baleen whales
with calves ``show a heightened response to noise and disturbance,''
there is no evidence that such ``heightened response'' is biologically
significant and constitutes a ``take'' under the MMPA. Nevertheless, in
the past NMFS has required a 120-dB safety zone for migrating bowhead
cow/calf pairs to be implemented (see Federal Register notice for
proposed IHA to Shell; 75 FR 22708; May 18, 2010). However, in the
Chukchi Sea, the migratory corridor for bowhead whales is wider and
more open, thus the 120-dB ensonified zone would not impede bowhead
whale migration. The animals would be able to swim around the
ensonified area. Additionally, NMFS has not imposed a requirement to
conduct aerial monitoring of the 120-dB safety zone for the occurrence
of four or more cow-calf pairs in the Chukchi Sea because it is not
practicable. Especially for Statoil's proposed shallow hazards survey,
NMFS determined that monitoring the 120-dB zone of influence was not
necessary in the Chukchi Sea because there would not be the level of
effort by these surveys (i.e., a small 120-dB zone of about 39,000 m
radius). This provides cow/calf pairs with sufficient ability to move
around the seismic source without significant effort.
Monitoring Measures
Comment 7: The Commission recommends that prior to granting the
requested authorization, NMFS provide additional justification for its
preliminary determination that the proposed monitoring program will be
sufficient to detect, with a high level of confidence, all marine
mammals within or entering the identified Level B harassment zones.
Response: For this action, marine mammal monitoring serves two
primary purposes. One purpose (referred to as mitigation monitoring) is
to trigger mitigation measures--so that when a marine mammal is sighted
within or entering the identified 180 or 190-dB exclusion zones,
appropriate measures (speed/course change, power-down, or shutdown of
sound sources) can be implemented, thus minimizing the likelihood that
marine mammals are exposed to sound levels that have been associated
with injurious effects. The other purpose is to collect data regarding
the behavior and numbers of marine mammals detected within the larger
160-dB zone, which can be used both to refine Level B take estimates
and to add to our understanding of the nature and scale of marine
mammal behavioral responses to this activity. In the Federal Register
notice for the proposed IHA (76 FR 30110; May 24, 2011), NMFS provided
a thorough analysis of the proposed monitoring
[[Page 46734]]
measures and made a preliminary determination, based on the modality
that is proposed to be utilized for monitoring, prior years' marine
mammal visual monitoring measures as reported in the 90-day reports and
comprehensive reports for seismic surveys in the Arctic, and the small
exclusion zones (50 m [164 ft] from the source to where received levels
would be at 190 dB and above, and 190 m [623 ft] from the source to
where received levels would be at 180 dB and above) anticipated during
the proposed Statoil shallow hazards surveys. The analysis led NMFS to
conclude that the proposed monitoring program will be sufficient to
detect, with a high level of confidence, nearly all marine mammals
within or entering the identified 180 and 190 dB exclusion zone to
implement mitigation measures to prevent Level A harassment (injury).
The identified Level B harassment zone for Statoil's proposed
shallow hazards survey is modeled at 2,250 m (1.4 mi) from the source.
This distance is believed to be within reasonable range for visual
detection based on prior years' marine mammal monitoring during seismic
surveys in the Arctic (Aerts et al. 2008; Hauser et al. 2008;
Brueggeman 2009; Ireland et al. 2009; Reiser et al. 2010; 2011; Blees
et al. 2011). In addition, NMFS worked with Statoil on the
implementation of recommendations from the independent peer-review
panel of Statoil's monitoring plan and included a list of monitoring
measures recommended by the panel in the IHA. These measures that will
increase detectability include: (1) Maximizing the time spent looking
at the water and guarding the exclusion zones; (2) using ``big eye''
binoculars (e.g., 25 x 150 power) from high perches on large, stable
platforms; (3) pairing the use of ``big eyes'' with naked eye
searching; and (4) using the best possible positions for observing
(e.g., outside and as high on the vessel as possible), taking into
account weather and other working conditions. All these measures will
further increase marine mammal detectability within and around the
zones of influence for Level B harassment.
Although it may be difficult to detect all marine mammals that are
within or entering the larger 160-dB Level B harassment zone, these
observations will be corrected for animals undetected in the far field
and used to refine post-activity take estimates, which are then
reported in the 90-day report. Additionally, behavioral observations
within this zone are reported and more generally contribute to our
understanding of how marine mammals behaviorally respond to seismic
surveys.
Comment 8: AWL states that the IHA must prescribe the ``means of
effecting the least practicable impact'' on a species or stock and its
habitat, therefore, AWL argues, NMFS should also determine whether
there are further monitoring methods available, such as manned or
unmanned aerial surveys. Citing the peer-review panel report on open
water monitoring plans, AWL states that other far-field monitoring,
such as the use of scout vessels, passive acoustic platforms, and
satellites, should be studied as well. AWL argues that ``in order to
mitigate for some of the difficulties that arise from relying on visual
observation, NMFS should consider restricting airgun operations to
times in which the safety zones are visible to marine monitors,'' and
that ``Statoil should not operate in conditions--such as darkness, fog,
or rough seas--in which the observers are unable to ensure that the
designated safety zones are free of marine mammals.''
Response: During preparation of the SEA, NMFS considered several
additional technologies that could be used to enhance marine mammal
monitoring. These new technologies include the use of unmanned aerial
vehicles (UAVs), passive acoustic monitoring (PAM), and active acoustic
monitoring (AAM) for marine mammals. However, at this time, these
technologies are still being developed or refined. For example, while
there has been some testing of unmanned aerial vehicles conducted
recently, the technology has not yet been proven effective for
monitoring or mitigation, as would be required under an IHA.
Regarding the use of PAM, NMFS does not believe that at the current
stage, requiring PAM (either towed or stationary) for real-time
acoustic monitoring would yield reliable data (Guan et al. 2011).
During the 2010 open-water seismic survey, Statoil tested a towed PAM
for the presence of bowhead whales onboard a support vessel during the
seismic operations, and preliminary results show that the detection
rates were low (Bruce Martin, pers. comm. March 2011). As far as AAM is
concerned, many technical issues (such as detection range and
resolution) and unknowns (such as target strength of marine mammal
species in the Arctic) remain to be resolved before it can be used as a
reliable monitoring tool to aid in the implementation of mitigation
measures. Environmental consequences concerning additional sound being
introduced into the water column from an active sonar source also need
to be addressed. Therefore, NMFS does not believe it is beneficial to
adopt these ``emerging'' monitoring technologies based on their current
stages of research and development.
NMFS also considered AWL's suggestion of using scout vessels for
monitoring marine mammals beyond the visual field where they can be
detected by the source vessel. However, since the modeled exclusion
zones at received levels of 180 and 190 dB re 1 [mu]Pa extend out to
approximately 50 and 190 m (164 and 623 ft), respectively, NMFS
determined that these distances are within the visual ranges that can
be reliably detected by protected species observers (PSOs) onboard the
source vessel. Therefore, NMFS does not believe it is beneficial to
have additional scout vessels for marine mammal monitoring for this
particular survey. Furthermore, deploying additional vessels in the
vicinity of Statoil's proposed survey area would only increase
anthropogenic impacts to the environment by introducing additional
vessel noise into the water column. Concerning the manned aircraft
survey, NMFS typically does not require this measure in the Chukchi Sea
because it has been determined to be impracticable due to lack of
adequate landing facilities and the prevalence of fog and other
inclement weather in that area. This could potentially result in an
inability to return to the airport of origin, thereby resulting in
safety concerns.
NMFS recognizes the limitations of visual monitoring in darkness
and other inclement weather conditions. Therefore, in Statoil's IHA,
NMFS requires that no seismic airgun can be ramped up when the entire
exclusion zones are not visible (i.e., darkness or poor weather
conditions). However, Statoil's operations will occur in an area where
periods of darkness do not begin until early September. Beginning in
early September, there will be approximately 1-3 hours of darkness each
day, with periods of darkness increasing by about 30 min each day. By
the end of the survey period, there will be approximately 8 hours of
darkness each day. These conditions provide PSOs favorable monitoring
conditions for most of the time.
Subsistence Issues
Comment 9: AEWC states that NMFS failed to consider adequately the
potential impacts to the fall subsistence hunt of bowhead whales in
Chukchi Sea villages. Over the past several years, worsening ice
conditions have made it more dangerous and difficult for whale captains
and their crews to carry out the
[[Page 46735]]
larger spring bowhead whale hunt. Because of the changing conditions,
crews from Wainwright, Point Hope and Point Lay have all been
conducting fall hunts in an effort to provide for their communities and
meet their allotted quotas. Last year, Wainwright landed a bowhead
whale for the first time during the fall, which provided critical food
for the community and served as a great source of pride and
celebration.
Response: NMFS does not agree with AEWC's contention that it failed
to adequately consider impacts to the fall subsistence hunt. The
potential impacts from the proposed Statoil survey were fully analyzed
and addressed in both the Federal Register notice for the proposed IHA
(76 FR 30110; May 24, 2011) and in the SEA. The proposed survey area is
~160 km (~100 mi) northwest of Wainwright offshore. Based on the small
scale of the proposed shallow hazards survey, the radius of the modeled
160 dB isopleths is 2.25 km (1.4 mi) from the source, and the 120 dB
isopleths is about 39 km (24 mi) from the source. Therefore, the area
where the received level could reach 160 dB is approximately 140 km (87
mi) offshore. Subsistence whaling typically occurs nearshore. In the
Chukchi Sea region, the fall hunt is generally conducted in an area
that extends 16 km (10 mi) west of Barrow to 48 km (30 mi) north of
Barrow. This is also confirmed by AEWC in its comment letter that
``[s]ubsistence hunters have a limited hunting range and prefer to take
whales close to shore so as to avoid hauling a harvested whale a long
distance over which the whale could spoil. During the fall, however,
subsistence hunters in the Chukchi Sea will pursue bowhead whales as
far as 50 miles (80 km) from the coast in small, fiberglass boats.''
Therefore, it is highly unlikely that the fall subsistence hunt could
be affected given the industry activities would occur much further
offshore.
NEPA Concerns
Comment 10: AWL notes that NMFS is preparing a Programmatic EIS
(PEIS), and that without a final EIS, additional oil and gas
exploration in the Chukchi Sea is especially problematic given the
critical information gaps that still exist today. AWL states that
without information on the seasonal presence and distribution patterns
of marine mammals, the agency would find it challenging to meet its
obligations under the MMPA. AWL states that NMFS should refrain from
issuing additional authorizations until more is known.
Response: While the Final EIS is still being developed, NMFS
conducted a thorough analysis of the affected environment and
environmental consequences from seismic surveys in the Arctic in 2010
and prepared the 2010 EA specific to two open-water seismic activities
by Shell and Statoil. For the issuance of an IHA to Statoil for its
2011 open-water shallow hazards survey, NMFS has determined that the
information contained in the 2010 EA is adequate and that no
significant changes relating to the environment and potential impacts
from human activities have resulted since the 2010 EA, and that
Statoil's proposed 2011 open-water shallow hazards surveys are
essentially the same as the activities analyzed in the 2010 EA.
Therefore, the 2010 EA is incorporated by reference in the 2011 SEA for
the issuance of an IHA to Statoil for their open-water shallow hazards
surveys in 2011.
While the analysis contained in the Final EIS will apply more
broadly to Arctic oil and gas operations, NMFS' issuance of an IHA to
Statoil for the taking of several species of marine mammals incidental
to conducting its open-water shallow hazards survey in the Chukchi Sea
in 2011, as analyzed in the SEA, is not expected to significantly
affect the quality of the human environment. Statoil's surveys are not
expected to significantly affect the quality of the human environment
because of the limited duration and scope of operations. Additionally,
the SEA and the 2010 EA contained a full analysis of cumulative
impacts.
Miscellaneous Issues
Comment 11: AEWC states that in the past, they have remained in
close communication with Statoil in the hopes that Statoil would be
able to reach agreement with their whaling captains on a set of
mitigation measures to protect subsistence whaling activities, but
Statoil has been unwilling to enter into a Conflict Avoidance Agreement
(CAA) with the impacted communities. In the absence of the signed CAA,
AEWC requests that NMFS adopt, as mandatory requirements set forth in
the IHA, the mitigation measures found in Titles II (Open Water Season
Communications) and V (Avoiding Conflicts During the Open Water Season)
of the 2011 CAA, which is attached with the AEWC comment letter.
Response: As NMFS has mentioned previously, the signing of a CAA is
not a requirement to obtain an IHA. The CAA is a document that is
negotiated between and signed by the industry participant, AEWC, and
the Village Whaling Captains' Associations. NMFS has no role in the
development or execution of this agreement. Although the contents of a
CAA may inform NMFS' no unmitigable adverse impact determination for
bowhead and beluga whales, the signing of it is not a requirement.
While a CAA has not been signed and a final version agreed to by
industry participants, AEWC, and the Village Whaling Captains'
Associations has not been provided, NMFS was provided with a copy of
the version ready for signature by AEWC. NMFS has reviewed the CAA and
included several measures from Titles II and V of the document which
relate to marine mammals and avoiding conflicts with subsistence hunts
in the IHA. Some of the conditions which have been added to the IHA
include: (1) Avoiding concentrations of whales and reducing vessel
speed when near whales; (2) conducting sound source verification
measurements; and (3) participating in the Communication Centers.
Despite the lack of a signed CAA for 2011 activities, NMFS is confident
that the measures contained in the IHA (some of which were taken
directly from the 2011 CAA) will ensure no unmitigable adverse impact
to subsistence users.
In addition, Statoil has agreed to utilize the Wainwright
communication center (Com-Center) in order to communicate with
subsistence vessels during its 2011 operations. The Com-Center will be
staffed by Inupiat operators where practicable. The Com-Center will be
operated twenty-four (24) hours per day during the 2011 subsistence
bowhead whale hunt. The Com-Center will have an Inupiat operator on
duty 24 hours per day from August 15 until the end of the 2011
subsistence bowhead whale hunt and during Statoil's 2011 activities in
the Chukchi Sea. The Com-Center will be managed and overseen by the
Olgoonik-Fairweather JV. The Com-Center operators will be available to
receive radio and telephone calls and to call vessels.
Following the completion of the 2011 Chukchi Sea open-water season
and prior to the 2012 Preseason Introduction Meetings, Statoil, if
requested by the AEWC or the Whaling Captains' Association of each
village, will host a meeting in each of the following villages:
Wainwright, Pt. Lay, Pt. Hope, and Barrow (or a joint meeting of the
whaling captains from all of these villages if the whaling captains
agree to a joint meeting) to review the results of the 2011 operations
and to discuss any concerns residents of those villages might have
regarding the operations. To the extent possible, the meetings will
include the PSOs stationed on Statoil's vessels in the Chukchi Sea.
[[Page 46736]]
In summary, the measures that Statoil has taken, and will take,
under the POC and Marine Mammal Monitoring and Mitigation Plan (4MP)
are similar to the measures identified in the draft CAA provided by
AEWC. Below, Statoil and NMFS identify the key conflict-avoidance
provisions of the CAA, and identify the corresponding provisions of the
POC, 4MP, and the Participation Agreement focused on minimizing impacts
to the environment and subsistence resources in the Chukchi Sea.
Regarding AEWC's request for NMFS to adopt certain sections of the
2011 CAA as the mitigation measures (i.e., Title II and Title V), NMFS
carefully reviewed these sections and found that they are within the
mitigation measures NMFS prescribed to Statoil under the IHA issued for
mitigating subsistence harvest during Statoil's proposed shallow
hazards surveys in the Chukchi Sea during the 2011 open-water season.
However, these sections also contain requirements that NMFS does not
believe are pertinent to Statoil's proposed 2011 open-water shallow
hazards surveys. For instance, the draft CAA calls for funding of Com-
Centers and to provide communication equipment in Deadhorse and
Kaktovik, which are villages on the coast of the Beaufort Sea, far away
from Statoil's planned Chukchi Sea operations. Therefore, NMFS does not
believe it is appropriate to adopt these sections of the draft CAA in
their entirety as mitigation measures for subsistence.
Monitoring Plan Peer Review
The MMPA requires that monitoring plans be independently peer
reviewed ``where the proposed activity may affect the availability of a
species or stock for taking for subsistence uses'' (16 U.S.C.
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing
regulations state, ``Upon receipt of a complete monitoring plan, and at
its discretion, [NMFS] will either submit the plan to members of a peer
review panel for review or within 60 days of receipt of the proposed
monitoring plan, schedule a workshop to review the plan'' (50 CFR
216.108(d)).
NMFS convened an independent peer review panel to review Statoil's
Marine Mammal Monitoring and Mitigation Plan (4MP) for Shallow Hazards
and Site Clearance Surveys and Geotechnical Soil Investigations in the
Alaskan Chukchi Sea, 2011. The panel met on March 9, 2011, and provided
their final report to NMFS on April 27, 2011. The full panel report can
be viewed at: http://www.nmfs.noaa.gov/pr/pdfs/permits/openwater/peer_review_report2011.pdf.
NMFS provided the panel with Statoil's 4MP and asked the panel to
address the following questions and issues for Statoil's plan:
(1) Are the applicant's stated objectives the most useful for
understanding impacts on marine mammals and otherwise accomplishing the
goals stated in the paragraph above?
(2) Are the applicant's stated objectives able to be achieved based
on the methods described in the plan?
(3) Are there techniques not proposed by the applicant, or
modifications to the techniques proposed by the applicant, that should
be considered for inclusion in the applicant's monitoring program to
better accomplish the goals stated above?
(4) 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?
Section 4 of the report contains recommendations that the panel
members felt were applicable to all of the monitoring plans that they
reviewed this year. Section 5.1 of the report contains recommendations
specific to Statoil's 2011 shallow hazards survey monitoring plan.
Specifically, for the general recommendations, the panel commented on
issues related to: (1) Acoustic effects of oil and gas exploration--
assessment and mitigation; (2) aerial surveys; (3) marine mammal
observers; (4) visual near-field monitoring; (5) visual far-field
monitoring; (6) baseline biological and environmental information; (7)
comprehensive ecosystem assessments and cumulative impacts; (8)
duplication of seismic survey effort; (9) improving take estimates and
statistical inference into effects of the activity; and (10) improving
the peer-review process.
NMFS has reviewed the report and evaluated all recommendations made
by the panel. NMFS has determined that there are several measures that
Statoil can incorporate into its 2011 open-water shallow hazards
surveys 4MP to improve it. Additionally, there are other
recommendations that NMFS has determined would also result in better
data collection and could potentially be implemented by oil and gas
industry applicants, but which likely could not be implemented for the
2011 open-water season due to technical issues (see below). While it
may not be possible to implement those changes this year, NMFS believes
that they are worthwhile and appropriate suggestions that may require a
bit more time to implement, and Statoil should consider incorporating
them into future monitoring plans should Statoil decide to apply for
IHAs in the future.
The following subsections lay out measures that NMFS recommends for
implementation as part of the 2011 open-water shallow hazards surveys
4MP and those that are recommended for future programs, as well as
recommendations for future MMPA authorization applications and
presentations at future Open Water Meetings. The panel recommendations
determined by NMFS that are appropriate for inclusion in the 2011
program have been discussed with Statoil and are included in the IHA.
Recommendations for Inclusion in the 2011 4MP and IHA
Section 4.3 of the report contains several recommendations
regarding marine mammal observers (PSOs). NMFS agrees that the
following measures should be incorporated into the 2011 Monitoring
Plan:
[cir] PSOs record additional details about unidentified marine
mammal sightings, such as ``blow only'', mysticete with (or without) a
dorsal fin, ``seal splash'', etc. That information should also be
included in 90-day and final reports.
In Section 4.7, panelists included a section regarding the
need for a more robust and comprehensive means of assessing the
collective or cumulative impact of many of the varied human activities
that contribute noise into the Arctic environment. Specifically, for
data analysis and integration, the panelists recommended, and NMFS
agrees, that the following recommendations be incorporated into the
2011 program:
[cir] To better assess impacts to marine mammals, data analysis
should be separated into periods when a seismic airgun array (or a
single mitigation airgun) is operating and when it is not. Final and
comprehensive reports to NMFS should summarize and plot:
[dec221] Data for periods when a seismic array is active and when
it is not; and
[dec221] The respective predicted received sound conditions over
fairly large areas (tens of km) around operations.
[cir] To better understand the potential effects of oil and gas
activities on marine mammals and to facilitate integration among
companies and other researchers, the following data should be obtained
and provided electronically in the final and comprehensive reports:
[dec221] The location and time of each aerial or vessel-based
sighting or acoustic detection;
[dec221] Position of the sighting or acoustic detection relative to
ongoing operations
[[Page 46737]]
(i.e., distance from sightings to seismic operation, drilling ship,
support ship, etc.), if known;
[dec221] The nature of activities at the time (e.g., seismic on/
off);
[dec221] Any identifiable marine mammal behavioral response
(sighting data should be collected in a manner that will not detract
from the PSO's ability to detect marine mammals); and
[dec221] Any adjustments made to operating procedures.
In Section 4.9, the panelists discussed improving take
estimates and statistical inference into effects of the activities.
NMFS agrees that the following measures should be incorporated into the
2011 Monitoring Plan:
[cir] Reported results from all hypothesis tests should include
estimates of the associated statistical power when practicable.
[cir] Estimate and report uncertainty in all take estimates.
Uncertainty could be expressed by the presentation of confidence
limits, a minimum-maximum, posterior probability distribution, etc.;
the exact approach would be selected based on the sampling method and
data available.
Section 5.1 of the report contains recommendations
specific to Statoil's 2011 shallow hazards survey monitoring plan. Of
the recommendations presented in this section, NMFS has determined that
the following should be implemented for the 2011 season:
[cir] Conduct sound source verification for the sub-bottom
profilers.
[cir] The report should clearly compare authorized takes to the
level of actual estimated takes.
[cir] As a starting point for integrating different data sources,
Statoil should present their 2010 and 2011 data by plotting acoustic
detections from bottom-mounted hydrophones and visual detections from
PSOs on a single map.
In addition, the panelists included a list of general
recommendations from the 2010 Peer-review Panel Report to be
implemented by operators in their 2011 open-water season activities.
NMFS agrees that the following recommendations should be implemented in
Statoil's 2011 monitoring plan:
[cir] Observers should be trained using visual aids (e.g., videos,
photos), to help them identify the species that they are likely to
encounter in the conditions under which the animals will likely be
seen.
[cir] Observers should understand the importance of classifying
marine mammals as ``unknown'' or ``unidentified'' if they cannot
identify the animals to species with confidence. In those cases, they
should note any information that might aid in the identification of the
marine mammal sighted (and this information should be included in the
report). For example, for an unidentified mysticete whale, the
observers should record whether the animal had a dorsal fin.
[cir] Observers should attempt to maximize the time spent looking
at the water and guarding the safety radii. They should avoid the
tendency to spend too much time evaluating animal behavior or entering
data on forms, both of which detract from their primary purpose of
monitoring the safety zone.
[cir] ``Big eye'' binoculars (e.g., 25 x 150 power) should be used
from high perches on large, stable platforms. They are most useful for
monitoring impact zones that extend beyond the effective line of sight.
With two or three observers on watch, the use of big eyes should be
paired with searching by naked eye, the latter allowing visual coverage
of nearby areas to detect marine mammals. When a single observer is on
duty, the observer should follow a regular schedule of shifting between
searching by naked eye, low-power binoculars, and big-eye binoculars
based on the activity, the environmental conditions, and the marine
mammals of concern.
[cir] Observers should use the best possible positions for
observing (e.g., outside and as high on the vessel as possible), taking
into account weather and other working conditions.
[cir] Observer teams should include Alaska Natives, and all
observers should be trained together. Whenever possible, new observers
should be paired with experienced observers to avoid situations where
lack of experience impairs the quality of observations.
[cir] Conduct efficacy testing of night-vision binoculars and other
such instruments to improve near-field monitoring under Arctic
conditions.
[cir] To help evaluate the utility of ramp-up procedures, PSOs
shall record, analyze, and report their observations during any ramp-up
period.
[cir] PSOs should carefully document visibility during observation
periods so that total estimates of take can be corrected accordingly.
Recommendations for Inclusion in Future Monitoring Plans
In Section 4.7 of the report, the panelists stated that advances in
integrating data from multiple platforms through the use of
standardized data formats are needed to increase the statistical power
to assess potential effects. Therefore, the panelists recommended that
industry examine this issue and jointly propose one or several data
integration methods to NMFS at the Open Water Meeting in 2012. NMFS
concurs with the recommendation and encourages Statoil to collaborate
with other companies to discuss data integration methods and to present
the results of those discussions at the 2012 Open Water Meeting.
In Section 4.7, the panel also recommended that Statoil's reports
include sightability curves (detection functions) for distance-based
analyses to help evaluate the effectiveness of PSOs and more
effectively estimate take. NMFS discussed this requirement with Statoil
on a technical basis and realizes that in most circumstances there are
often too few sightings of individual species recorded during a single
project to allow reliable estimates of sightability curves. Therefore,
sightability curves from previous comprehensive reports (where multi-
year or multi-project data have been pooled to achieve adequate sample
sizes) are often used and referenced in 90-day reports. Whenever future
monitoring data present enough data from a single project, sightability
curves will be provided in the report.
In Section 5.1, the panel recommended that Statoil consider other
new technologies (i.e., underwater vehicles, satellite monitoring,
etc.) to assess far-field monitoring. The panel also recommended
investigating other methods for far-field monitoring (e.g., unmanned
systems or scout vessels) to be implemented upon approval by NMFS. NMFS
agrees that new technologies should be considered to increase our
current knowledge regarding marine mammals that could be affected
beyond the line of sight from the vessel platform and will discuss this
issue with the industry at the 2012 Open Water Meeting.
The panel also recommended using the cluster array to localize
whale calls and evaluate the effects of sound on calling animal
distribution. However, based on the limited usefulness of data
collected on the cluster array last year (2010 open-water season), the
areas where the recording arrays were previously used for localizing
whales have been expanded to cover a much larger area in 2011, which
also include the Hanna Shoal area to potentially capture more
information on whale migration.
If more recording arrays are available in the future, NMFS will
work with Statoil to deploy these arrays within the proposed project
area for localizing calling whales.
[[Page 46738]]
Recommendations for Future Applications and Open Water Meetings
In Section 3, panelists recommended that companies specifically
report the changes they made in their operations as a result of the
previous years' panel recommendations. These should be highlighted in
the verbal presentations at the Open Water Meeting, discussed directly
with the review panel, and detailed in the 90-day reports (and final
reports, if appropriate). NMFS concurs with this recommendation and
requests that Statoil include this information in their 90-day report
submitted at the conclusion of operations and provide the information
in their presentation at the 2012 Open Water Meeting.
In Section 4.1, panelists made a recommendation that IHA holders
should report estimates of the spatio-temporal distributions of
acoustic levels. This could include reporting levels as low as the 120
dB level. NMFS agrees that applicants should include this information
in future MMPA application requests.
In Section 4.7, panelists included a recommendation that could be
helpful for the presentation of data at future Open Water Meetings. To
allow visualization and interpretation of the complex field of
anthropogenic activities and distributions and movements of marine
mammals, the final and comprehensive reports required by the IHA should
provide all spatial data on figures that depict the locations of the
principal sound sources. This could be represented by a diagram in
which all PSO sightings (vessel-based and aerial) and acoustic
detections are plotted relative to their distance and bearing from a
specific sound source. Alternatively, it could be depicted in a map of
the region, showing the operation area, tracklines of vessels and
aircraft (if applicable), PSO sightings (vessel-based and aerial), and
acoustic detections. To facilitate understanding of both the spatial
and temporal aspects of the activity and marine mammal responses, these
figures would ideally be animated, showing industry activities and
sightings or acoustic detections changing through time. Whenever
ancillary biological data (e.g., tagging, acoustic, broad-scale aerial
survey) are available that are coincident in space and time with the
activity, they should be included in these figures. NMFS encourages
Statoil to consider this recommendation when preparing figures and
videos for reports and the Open Water Meeting.
Recommendations From 2010 Peer-Review Panel for Inclusion in Future
Monitoring Plans
Section 3.5 of the 2010 Peer-review Panel report recommends methods
for conducting comprehensive monitoring of a large-scale seismic
operation. The panelists recommend adding a tagging component to
monitoring plans. ``Tagging of animals expected to be in the area where
the survey is planned also may provide valuable information on the
location of potentially affected animals and their behavioral responses
to industrial activities. Although the panel recognized that such
comprehensive monitoring might be difficult and expensive, such an
effort (or set of efforts) reflects the complex nature of the challenge
of conducting reliable, comprehensive monitoring for seismic or other
relatively-intense industrial operations that ensonify large areas of
ocean''. While this particular recommendation is not feasible for
implementation in 2011, NMFS recommends that Statoil consider adding a
tagging component to future monitoring plans should Statoil decide to
conduct such activities in future years.
Finally, the panel recommended that sightings be entered and
archived in a way that enables immediate geospatial depiction to
facilitate operational awareness and analysis of risks to marine
mammals. Real-time monitoring is especially important in areas of
seasonal migration or influx of marine mammals. NMFS worked with
Statoil and the panel to identify certain software packages for real-
time data entry, mapping, and analysis available for this purpose, but
it does not seem that a commercially viable software system is
available at this time.
Description of Marine Mammals in the Area of the Specified Activity
Nine cetacean and four seal species could occur in the general area
of the site clearance and shallow hazards survey. The marine mammal
species under NMFS' jurisdiction most likely to occur near operations
in the Chukchi Sea include four cetacean species: Beluga whale
(Delphinapterus leucas), bowhead whale (Balaena mysticetus), gray whale
(Eschrichtius robustus), and harbor porpoise (Phocoena phocoena), and
three seal species: Ringed (Phoca hispida), spotted (P. largha), and
bearded seals (Erignathus barbatus). The marine mammal species that is
likely to be encountered most widely (in space and time) throughout the
period of the planned site clearance and shallow hazards surveys is the
ringed seal.
Other marine mammal species that have been observed in the Chukchi
Sea but are less frequent or uncommon in the project area include
narwhal (Monodon monoceros), killer whale (Orcinus orca), fin whale
(Balaenoptera physalus), minke whale (B. acutorostrata), humpback whale
(Megaptera novaeangliae), and ribbon seal (Histriophoca fasciata).
These species could occur in the project area, but each of these
species is uncommon or rare in the area and relatively few encounters
with these species are expected during the proposed shallow hazards
survey. The narwhal occurs in Canadian waters and occasionally in the
Beaufort Sea, but it is rare there and is not expected to be
encountered. There are scattered records of narwhal in Alaskan waters,
including reports by subsistence hunters, where the species is
considered extralimital (Reeves et al. 2002).
The bowhead, fin, and humpback whales are listed as ``endangered''
under the Endangered Species Act (ESA) and as depleted under the MMPA.
Certain stocks or populations of gray, beluga, and killer whales and
spotted seals are listed as endangered or proposed for listing under
the ESA; however, none of those stocks or populations occur in the
proposed activity area. Additionally, the ribbon seal is considered a
``species of concern'' under the ESA. On December 10, 2010, NMFS
published a notification of proposed threatened status for subspecies
of the ringed seal (75 FR 77476) and a notification of proposed
threatened and not warranted status for subspecies and distinct
population segments of the bearded seal (75 FR 77496) in the Federal
Register. Neither species is considered depleted under the MMPA. The
polar bear (which is listed as threatened under the ESA) and walrus
also occur in the Chukchi Sea. However, both species are under the
jurisdiction of the U.S. Fish and Wildlife Service and are therefore
not discussed further in this document.
Statoil's application contains information on the status,
distribution, seasonal distribution, and abundance of each of the
species under NMFS' jurisdiction mentioned in this document. Please
refer to the application for that information (see ADDRESSES).
Additional information can also be found in the NMFS Stock Assessment
Reports (SAR). The Alaska 2010 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2010.pdf.
[[Page 46739]]
Potential Effects of the Specified Activity on Marine Mammals
Operating active acoustic sources such as an airgun array has the
potential for adverse effects on marine mammals.
Potential Effects of Airgun Sounds on Marine Mammals
The effects of sounds from airgun pulses might include one or more
of the following: Tolerance, masking of natural sounds, behavioral
disturbance, and temporary or permanent hearing impairment or non-
auditory effects (Richardson et al. 1995). As outlined in previous NMFS
documents, the effects of noise on marine mammals are highly variable.
The Notice of Proposed IHA (76 FR 30110; May 24, 2011) included a
discussion of the effects of airguns on marine mammals, which is not
repeated here. That discussion did not take into consideration the
monitoring and mitigation measures proposed by Statoil and NMFS. No
cases of temporary threshold shift (TTS) are expected as a result of
Statoil's activities given the small size of the source, the strong
likelihood that baleen whales (especially migrating bowheads) would
avoid the approaching airguns (or vessel) before being exposed to
levels high enough for there to be any possibility of TTS, and the
mitigation measures required to be implemented during the survey
described later in this document. Based on the fact that the sounds
produced by Statoil's operations are unlikely to cause TTS in marine
mammals, it is extremely unlikely that permanent hearing impairment
would result. No injuries or mortalities are anticipated as a result of
Statoil's operations, and none are authorized to occur. Only Level B
harassment is anticipated as a result of Statoil's activities.
Potential Effects From Active Sonar Equipment on Marine Mammals
Several active acoustic sources other than the four 10 in\3\ airgun
have been proposed for Statoil's 2011 open water shallow hazards survey
in the Chukchi Sea. The specifications of this sonar equipment (source
levels and frequency ranges) were provided in the Notice of Proposed
IHA (76 FR 30110; May 24, 2011). In general, the potential effects of
this equipment on marine mammals are similar to those from the airgun,
except the magnitude of the impacts is expected to be much less due to
the lower intensity and higher frequencies. In some cases, due to the
fact that the operating frequencies of some of this equipment (e.g.,
Multi-beam echosounder: frequency at 200-400 kHz) are above the hearing
ranges of marine mammals, they are not expected to have any impacts to
marine mammals. The Notice of Proposed IHA (76 FR 30110; May 24, 2011)
contains a discussion of impacts to marine mammals from vessel sounds,
which is not repeated here.
Anticipated Effects on Habitat
The primary potential impacts to marine mammals and other marine
species are associated with elevated sound levels produced by airguns
and other active acoustic sources. However, other potential impacts to
the surrounding habitat from physical disturbance are also possible.
Potential Impacts on Prey Species
With regard to fish as a prey source for cetaceans and pinnipeds,
fish are known to hear and react to sounds and to use sound to
communicate (Tavolga et al. 1981) and possibly avoid predators (Wilson
and Dill 2002). Experiments have shown that fish can sense both the
strength and direction of sound (Hawkins 1981). Primary factors
determining whether a fish can sense a sound signal, and potentially
react to it, are the frequency of the signal and the strength of the
signal in relation to the natural background noise level.
The level of sound at which a fish will react or alter its behavior
is usually well above the detection level. Fish have been found to
react to sounds when the sound level increased to about 20 dB above the
detection level of 120 dB (Ona 1988); however, the response threshold
can depend on the time of year and the fish's physiological condition
(Engas et al. 1993). In general, fish react more strongly to pulses of
sound rather than a continuous signal (Blaxter et al. 1981), and a
quicker alarm response is elicited when the sound signal intensity
rises rapidly compared to sound rising more slowly to the same level.
Investigations of fish behavior in relation to vessel noise (Olsen
et al. 1983; Ona 1988; Ona and Godo 1990) have shown that fish react
when the sound from the engines and propeller exceeds a certain level.
Avoidance reactions have been observed in fish such as cod and herring
when vessels approached close enough that received sound levels are 110
dB to 130 dB (Nakken 1992; Olsen 1979; Ona and Godo 1990; Ona and
Toresen 1988). However, other researchers have found that fish such as
polar cod, herring, and capelin are often attracted to vessels
(apparently by the noise) and swim toward the vessel (Rostad et al.
2006). Typical sound source levels of vessel noise in the audible range
for fish are 150 dB to 170 dB (Richardson et al. 1995).
Some mysticetes, including bowhead whales, feed on concentrations
of zooplankton. Some feeding bowhead whales may occur in the Alaskan
Beaufort Sea in July and August, and others feed intermittently during
their westward migration in September and October (Richardson and
Thomson [eds.] 2002; Lowry et al. 2004). However, by the time most
bowhead whales reach the Chukchi Sea (October), they will likely no
longer be feeding, or if it occurs it will be very limited. A reaction
by zooplankton to a seismic impulse would only be relevant to whales if
it caused concentrations of zooplankton to scatter. Pressure changes of
sufficient magnitude to cause that type of reaction would probably
occur only very close to the source. Impacts on zooplankton behavior
are predicted to be negligible, and that would translate into
negligible impacts on feeding mysticetes. Thus, the activity is not
expected to have any habitat-related effects that could cause
significant or long-term consequences for individual marine mammals or
their populations.
Mitigation Measures
In order to issue an incidental take authorization under Section
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods
of taking pursuant to such activity, and other means of effecting the
least practicable impact on such species or stock and its habitat,
paying particular attention to rookeries, mating grounds, and areas of
similar significance, and on the availability of such species or stock
for taking for certain subsistence uses.
For Statoil's open-water shallow hazards survey in the Chukchi Sea,
Statoil worked with NMFS and agreed upon the following mitigation
measures to minimize the potential impacts to marine mammals in the
project vicinity as a result of the shallow hazards survey activities.
As part of the application, Statoil submitted to NMFS a Marine
Mammal Monitoring and Mitigation Program (4MP) for its open-water
shallow hazards survey in the Chukchi Sea during the 2011 open-water
season. The objectives of the 4MP are:
To ensure that disturbance to marine mammals and
subsistence hunts is minimized and all permit stipulations are
followed,
To document the effects of the proposed survey activities
on marine mammals, and
[[Page 46740]]
To collect baseline data on the occurrence and
distribution of marine mammals in the study area.
The 4MP has been modified based on comments received from the peer
review panel (see the ``Monitoring Plan Peer Review'' section earlier
in this document).
For Statoil's 2011 open-water shallow water hazards surveys in the
Chukchi Sea, the following mitigation measures are required.
(1) Sound Source Measurements
Previous measurements of similar airgun arrays in the Chukchi Sea
were used to model the distances at which received levels are likely to
fall below 120, 160, 180, and 190 dB re 1 [mu]Pa (rms) from the planned
airgun sources. These modeled distances will be used as temporary
exclusion radii until measurements of the airgun sound source are
conducted. The measurements will be made at the beginning of the field
season, and the measured radii used for the remainder of the survey
period.
The objectives of the sound source verification measurements
planned for 2011 in the Chukchi Sea will be to measure the distances at
which broadband received levels reach 190, 180, 170, 160, and 120
dBrms re 1 [mu]Pa for the airgun configurations that may be
used during the survey activities. The configurations will include at
least the full array (4 x 10 in\3\) and the operation of a single 10
in\3\ airgun that will be used during power downs or very shallow
penetration surveys. The measurements of airgun sounds will be made by
an acoustics contractor at the beginning of the survey. The distances
to the various radii will be reported as soon as possible after
recovery of the equipment. The primary radii of concern will be the 190
and 180 dB exclusion radii for pinnipeds and cetaceans, respectively,
and the 160 dB disturbance radii. In addition to reporting the radii of
specific regulatory concern, nominal distances to other sound isopleths
down to 120 dBrms will be reported in increments of 10 dB.
Sound levels during soil investigation operations will also be
measured. However, source levels are not expected to be strong enough
to require mitigation actions at the 190 dB or 180 dB levels.
Data will be previewed in the field immediately after download from
the hydrophone instruments. An initial sound source analysis will be
supplied to NMFS and the vessel within 120 hours of completion of the
measurements, if possible. The report will indicate the distances to
sound levels based on fits of empirical transmission loss formulae to
data in the endfire and broadside directions. A more detailed report
will be submitted to NMFS as part of the 90-day report following
completion of the acoustic program.
(2) Exclusion Zones
Under current NMFS guidelines, ``exclusion zones'' for marine
mammal exposure to impulse sources are customarily defined as the
distances within which received sound levels are >= 180
dBrms re 1 [mu]Pa for cetaceans and >= 190 dBrms
re 1 [mu]Pa for pinnipeds. These criteria are based on an assumption
that SPLs received at levels lower than these will not injure these
animals or impair their hearing abilities, but that at higher levels
they might have some such effects. Disturbance or behavioral effects to
marine mammals from underwater sound may occur after exposure to sound
at distances greater than the exclusion zones (Richardson et al. 1995).
Initial exclusion and disturbance zones for the sound levels
produced by the planned airgun configurations have been estimated
(Table 1). These zones will be used for mitigation purposes until
results of direct measurements are available early during the
exploration activities. The proposed surveys will use an airgun source
composed of four 10-in\3\ airguns (total discharge volume of 40 in\3\)
and a single 10 in\3\ airgun. Underwater sound propagation from a
similar 4 x 10-in\3\ airgun cluster and single 10 in\3\ was measured in
2009 (Reiser et al. 2010). Those measurements resulted in 90th
percentile propagation loss equations of RL = 218.0 - 17.5LogR -
0.00061R for the 4 x 10 in\3\ airgun cluster and RL = 204.4 - 16.0LogR
- 0.00082R for the single 10 in\3\ airgun (where RL = received level
and R = range). The estimated distances for the 2011 activities are
based on a 25% increase over 2009 results (Table 1).
In addition to the site surveys, Statoil plans to use a dedicated
vessel to conduct geotechnical soil investigations. Sounds produced by
the vessel and soil investigation equipment are not expected to be
above 180 dB (rms). Therefore, mitigation related to acoustic impacts
from these activities is not expected to be necessary.
An acoustics contractor will perform direct measurements of the
received levels of underwater sound versus distance and direction from
the airguns and soil investigation vessel using calibrated hydrophones.
The acoustic data will be analyzed as quickly as reasonably practicable
in the field and used to verify and adjust the exclusion zones. The
field report will be made available to NMFS and the PSOs within 120 hrs
of completing the measurements. The mitigation measures to be
implemented at the 190 and 180 dB sound levels will include power downs
and shut downs as described below.
Table 1--Distances to Specified Received Levels Measured From a 4 x 10 In\3\ Airgun Cluster and a Single 10-
in\3\ Airgun on the Burger Prospect in 2009 as Reported by Reiser et al. (2010). The 2011 ``Pre-SSV'' Distances
are a Precautionary 25% Increase Above the Reported 2009 Results and Will Be Used by PSOs for Mitigation
Purposes Until an SSV is Completed in 2011
----------------------------------------------------------------------------------------------------------------
Distance (m)
-----------------------------------------------------------------------
Received levels (dB re 1 [mu]Pa rms) Airgun cluster (4 x 10 in\3\) Single airgun (1 x 10 in\3\)
-----------------------------------------------------------------------
2009 Results 2011 pre-SSV 2009 Results 2011 pre-SSV
----------------------------------------------------------------------------------------------------------------
190..................................... 39 50 8 10
180..................................... 150 190 34 45
160..................................... 1,800 2,250 570 715
120..................................... 31,000 39,000 19,000 24,000
----------------------------------------------------------------------------------------------------------------
[[Page 46741]]
(3) Speed and Course Alterations
If a marine mammal is detected outside the applicable exclusion
zone and, based on its position and the relative motion, is likely to
enter the exclusion radius, changes of the vessel's speed and/or direct
course will be considered if this does not compromise operational
safety. For marine seismic surveys using large streamer arrays, course
alterations are not typically possible. However, for the smaller airgun
array and streamer planned during Statoil's site surveys, such changes
may be possible. After any such speed and/or course alteration is
begun, the marine mammal activities and movements relative to the
survey vessel will be closely monitored to ensure that the marine
mammal does not approach within the applicable exclusion zone. If the
mammal appears likely to enter the exclusion zone, further mitigative
actions will be taken, including a power down or shut down of the
airgun(s).
In addition, Statoil vessels are required to comply with the
following conditions concerning their speed with their relation of
distances to whales:
All vessels should reduce speed when within 300 yards (274
m) of whales, and those vessels capable of steering around such groups
should do so. Vessels may not be operated in such a way as to separate
members of a group of whales from other members of the group;
Avoid multiple changes in direction and speed when within
300 yards (274 m) of whales; and
When weather conditions require, such as when visibility
drops, support vessels must adjust speed (increase or decrease) and
direction accordingly to avoid the likelihood of injury to whales.
(4) Power Downs
A power down for immediate mitigation purposes is the immediate
reduction in the number of operating airguns such that the exclusion
zones of the 190 dBrms and 180 dBrms areas are
decreased to the extent that an observed marine mammal(s) are not in
the applicable exclusion zone of the full array. Power downs are also
used while the vessel turns from the end of one survey line to the
start of the next. During a power down, one airgun (or some other
number of airguns less than the full airgun array) continues firing.
The continued operation of one airgun is intended to (a) Alert marine
mammals to the presence of the survey vessel in the area, and (b)
retain the option of initiating a ramp up to full operations under poor
visibility conditions.
The array will be immediately powered down whenever a marine mammal
is sighted approaching close to or within the applicable exclusion zone
of the full array but is outside the applicable exclusion zone of the
single mitigation airgun. Likewise, if a mammal is already within the
exclusion zone when first detected, the airguns will be powered down
immediately. If a marine mammal is sighted within or about to enter the
applicable exclusion zone of the single airgun, it too will be shut
down (see following section).
Following a power down, operation of the full airgun array will not
resume until the marine mammal has cleared the exclusion zone. The
animal will be considered to have cleared the exclusion zone if it:
Is visually observed to have left the exclusion zone of
the full array, or
Has not been seen within the zone for 15 min in the case
of pinnipeds or small odontocetes, or
Has not been seen within the zone for 30 min in the case
of mysticetes or large odontocetes.
(5) Shut Downs
The operating airgun(s) will be shut down completely if a marine
mammal approaches or enters the then-applicable exclusion zone, and a
power down is not practical or adequate to reduce exposure to less than
190 or 180 dBrms, as appropriate. In most cases, this means
the mitigation airgun will be shut down completely if a marine mammal
approaches or enters the estimated exclusion zone around the single 10
in\3\ airgun while it is operating during a power down. Airgun activity
will not resume until the marine mammal has cleared the exclusion zone.
The animal will be considered to have cleared the exclusion zone as
described above under power down procedures.
A shut down of the borehole drilling equipment may be requested by
PSOs if an animal is sighted approaching the vessel close enough to
potentially interact with and be harmed by the soil investigation
operation.
(6) Ramp Ups
A ramp up of an airgun array provides a gradual increase in sound
levels and involves a step-wise increase in the number and total volume
of airguns firing until the full volume is achieved. The purpose of a
ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds in
the vicinity of the airguns and to provide the time for them to leave
the area and thus avoid any potential injury or impairment of their
hearing abilities.
During the proposed site survey program, the seismic operator will
ramp up the airgun cluster slowly. Full ramp ups (i.e., from a cold
start after a shut down, when no airguns have been firing) will begin
by firing a single airgun in the array. The minimum duration of a shut-
down period, i.e., without airguns firing, which must be followed by a
ramp up is typically the amount of time it would take the source vessel
to cover the 180-dB exclusion zone. Given the small size of the planned
airgun array, it is estimated that period would be about 1-2 minutes
based on the modeling results described above and a survey speed of 4
kts.
A full ramp up, after a shut down, will not begin until there has
been a minimum of 30 minutes of observation of the exclusion zone by
PSOs to ensure that no marine mammals are present. The entire exclusion
zone must be visible during the 30-minute lead-in to a full ramp up. If
the entire exclusion zone is not visible, then ramp up from a cold
start cannot begin. If a marine mammal(s) is sighted within the
exclusion zone during the 30-minute watch prior to ramp up, ramp up
will be delayed until the marine mammal(s) is sighted outside of the
exclusion zone or the animal(s) is not sighted for at least 15-30
minutes: 15 minutes for small odontocetes and pinnipeds, or 30 minutes
for baleen whales and large odontocetes.
During turns or brief transits between survey transects, one airgun
will continue operating. The ramp-up procedure will still be followed
when increasing the source levels from one airgun to the full 4-airgun
cluster. However, keeping one airgun firing will avoid the prohibition
of a cold start during darkness or other periods of poor visibility.
Through use of this approach, survey operations can resume upon entry
to a new transect without the 30-minute watch period of the full
exclusion zone required for a cold start. PSOs will be on duty whenever
the airguns are firing during daylight and during the 30-min periods
prior to ramp-ups, as well as during ramp-ups. Daylight will occur for
24 hr/day until mid-August, so until that date PSOs will automatically
be observing during the 30-minute period preceding a ramp up. Later in
the season, PSOs will be called to duty at night to observe prior to
and during any ramp ups. The survey operator and PSOs will maintain
records of the times when ramp-ups start and when the airgun arrays
reach full power.
(7) Mitigation Measures Concerning Baleen Whale Aggregations
A 160-dB vessel monitoring zone for large whales will be
established and monitored in the Chukchi Sea during all
[[Page 46742]]
shallow hazards surveys. Whenever a large number of bowhead whales or
gray whales (12 or more whales of any age/sex class that appear to be
engaged in a non-migratory, significant biological behavior (e.g.,
feeding, socializing)) are observed during a vessel monitoring program
within the 160-dB exclusion zone around the survey operations, the
survey activity will not commence or will shut down, until no more than
12 whales are present within the 160-dB exclusion zone of shallow
hazards surveying operations.
(8) Subsistence Mitigation Measures
Statoil plans to introduce the following mitigation measures,
plans, and programs to potentially affected subsistence groups and
communities. These measures, plans, and programs have been effective in
past seasons of work in the Arctic and were developed in past
consultations with these communities.
Statoil will not be entering the Chukchi Sea until early August, so
there will be no potential conflict with spring bowhead whale or beluga
subsistence whaling in the polynya zone. Statoil's planned activities
area is ~100 mi (~161 km) northwest of Wainwright, which reduces the
potential impact to subsistence hunting activities occurring along the
Chukchi Sea coast.
The communication center in Wainwright will be jointly funded by
Statoil and other operators, and Statoil will routinely call the
communication center according to the established protocol while in the
Chukchi Sea. Depending on survey progress, Statoil may perform a crew
change in the Nome area in Alaska. The crew change will not involve the
use of helicopters. Statoil does have a contingency plan for a
potential transfer of a small number of crew via ship-to-shore vessel
at Wainwright. If this should become necessary, the Wainwright
communications center will be contacted to determine the appropriate
vessel route and timing to avoid potential conflict with subsistence
users.
Prior to survey activities, Statoil will identify transit routes
and timing to avoid other subsistence use areas and communicate with
coastal communities before operating in or passing through these areas.
Mitigation Conclusions
NMFS has carefully evaluated the applicant's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that NMFS prescribes the means of effecting the least
practicable impact on the affected marine mammal species and stocks and
their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another:
The manner in which, and the degree to which, the
successful implementation of the measure is expected to minimize
adverse impacts to marine mammals;
The proven or likely efficacy of the specific measure to
minimize adverse impacts as planned; and
The practicability of the measure for applicant
implementation.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS and proposed by the
independent peer review panel, NMFS has determined that the proposed
mitigation measures provide the means of effecting the least
practicable impact on marine mammal species or stocks and their
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance.
Monitoring and Reporting Measures
In order to issue an ITA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs
must include the suggested means of accomplishing the necessary
monitoring and reporting that will result in increased knowledge of the
species and of the level of taking or impacts on populations of marine
mammals that are expected to be present in the proposed action area.
Monitoring Measures
The following monitoring measures are required for Statoil's 2011
open-water shallow hazards surveys in the Chukchi Sea.
(1) Vessel-Based PSOs
Vessel-based monitoring for marine mammals will be done by trained
PSOs throughout the period of marine survey activities. PSOs will
monitor the occurrence and behavior of marine mammals near the survey
vessel during all daylight periods during operation and during most
daylight periods when airgun operations are not occurring. PSO duties
will include watching for and identifying marine mammals, recording
their numbers, distances, and reactions to the survey operations, and
documenting ``take by harassment'' as defined by NMFS.
A sufficient number of PSOs will be required onboard the survey
vessel to meet the following criteria: (1) 100% monitoring coverage
during all periods of survey operations in daylight; (2) maximum of 4
consecutive hours on watch per PSO; and (3) maximum of 12 hours of
watch time per day per PSO.
PSO teams will consist of Inupiat observers and experienced field
biologists. An experienced field crew leader will supervise the PSO
team onboard the survey vessel. The total number of PSOs may decrease
later in the season as the duration of daylight decreases. Statoil
currently plans to have 5 PSOs aboard the site survey vessel and 3 PSOs
aboard the soil investigation vessel, with the potential of reducing
the number of PSOs later in the season as daylight periods decrease in
length.
Crew leaders and most other biologists serving as observers in 2011
will be individuals with experience as observers during recent seismic
or shallow hazards monitoring projects in Alaska, the Canadian
Beaufort, or other offshore areas in recent years.
Observer teams shall include Alaska Natives, and all observers
shall be trained together. Whenever possible, new observers shall be
paired with experienced observers to avoid situations where lack of
experience impairs the quality of observations.
Observers will complete a two or three-day training session on
marine mammal monitoring, to be conducted shortly before the
anticipated start of the 2011 open-water season. The training
session(s) will be conducted by qualified marine mammalogists with
extensive crew-leader experience during previous vessel-based
monitoring programs. A marine mammal observers' handbook, adapted for
the specifics of the planned survey program will be reviewed as part of
the training.
Primary objectives of the training include:
Review of the marine mammal monitoring plan for this
project, including any amendments specified by NMFS in the IHA, by
USFWS or Bureau of Ocean Energy Management, Regulation and Enforcement
(BOEMRE), or by other agreements in which Statoil may elect to
participate;
Review of marine mammal sighting, identification, and
distance estimation methods;
Review of operation of specialized equipment (reticle
binoculars, night vision devices [NVDs], and GPS system);
Review of, and classroom practice with, data recording and
data entry systems, including procedures for
[[Page 46743]]
recording data on marine mammal sightings, monitoring operations,
environmental conditions, and entry error control. These procedures
will be implemented through use of a customized computer database and
laptop computers;
Review of the specific tasks of the Inupiat Communicator.
Observers should be trained using visual aids (e.g., videos,
photos), to help them identify the species that they are likely to
encounter in the conditions under which the animals will likely be
seen.
Observers should attempt to maximize the time spent looking at the
water and guarding the exclusion radii. They should avoid the tendency
to spend too much time evaluating animal behavior or entering data on
forms, both of which detract from their primary purpose of monitoring
the exclusion zone.
Observers should use the best possible positions for observing
(e.g., outside and as high on the vessel as possible), taking into
account weather and other working conditions.
The observer(s) will watch for marine mammals from the best
available vantage point on the survey vessels, typically the bridge.
The observer(s) will scan systematically with the unaided eye and 7 x
50 reticle binoculars, supplemented with 20 x 60 image-stabilized Zeiss
Binoculars or Fujinon 25 x 150 ``Big-eye'' binoculars, and night-vision
equipment when needed (see below). Personnel on the bridge will assist
the PSOs in watching for marine mammals.
Information to be recorded by PSOs will include the same types of
information that were recorded during recent monitoring programs
associated with industry activity in the Arctic (e.g., Ireland et al.
2009). When a mammal sighting is made, the following information about
the sighting will be recorded:
(A) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from the PSO, apparent reaction to
activities (e.g., none, avoidance, approach, paralleling, etc.),
closest point of approach, and behavioral pace;
(B) Time, location, speed, activity of the vessel, sea state, ice
cover, visibility, and sun glare;
(C) The positions of other vessel(s) in the vicinity of the PSO
location;
(D) Any identifiable marine mammal behavioral response (sighting
data should be collected in a manner that will not detract from the
PSO's ability to detect marine mammals);
(E) any adjustments made to operating procedures; and
(F) observations during any ramp-up period.
Observers should understand the importance of classifying marine
mammals as ``unknown'' or ``unidentified'' if they cannot identify the
animals to species with confidence. In those cases, they should note
any information that might aid in the identification of the marine
mammal sighted (and this information should be included in the report).
For example, for an unidentified mysticete whale, the observers should
record whether the animal had a dorsal fin.
Additional details about unidentified marine mammal sightings, such
as ``blow only'', mysticete with (or without) a dorsal fin, ``seal
splash'', etc., shall be recorded. That information should also be
included in 90-day and final reports.
PSOs should carefully document visibility during observation
periods so that total estimates of take can be corrected accordingly.
The ship's position, speed of support vessels, and water
temperature, water depth, sea state, ice cover, visibility, and sun
glare will also be recorded at the start and end of each observation
watch, every 30 minutes during a watch, and whenever there is a change
in any of those variables.
Monitoring at Night and in Poor Visibility
Night-vision equipment (Generation 3 binocular image intensifiers,
or equivalent units) will be available for use when/if needed. Past
experience with NVDs in the Beaufort and Chukchi seas and elsewhere has
indicated that NVDs are not nearly as effective as visual observation
during daylight hours (e.g., Harris et al. 1997, 1998; Moulton and
Lawson 2002).
Conduct efficacy testing of night-vision binoculars and other such
instruments to improve near-field monitoring under Arctic conditions
and compare with the 2010 monitoring results.
(2) Acoustic Monitoring
Sound Source Measurements
As described above, previous measurements of airguns in the Chukchi
Sea were used to estimate the distances at which received levels are
likely to fall below 120, 160, 180, and 190 dBrms from the
planned airgun sources. These modeled distances will be used as
temporary exclusion radii until measurements of the airgun sound source
are conducted. The measurements will be made at the beginning of the
field season and the measured radii used for the remainder of the
survey period. An acoustics contractor will use their equipment to
record and analyze the underwater sounds and write the summary reports
as described below.
The objectives of the sound source verification measurements
planned for 2011 in the Chukchi Sea will be to measure the distances at
which broadband received levels reach 190, 180, 170, 160, and 120
dBrms re 1 [micro]Pa for the airgun configurations that may
be used during the survey activities. The configurations will include
at least the full array (4 x 10 in\3\) and the operation of a single 10
in\3\ airgun that will be used during power downs or very shallow
penetration surveys.
2011 Joint Environmental Studies Program
Statoil, Shell Offshore, Inc. (Shell), and CPAI are working on
plans to once again jointly fund an extensive environmental studies
program in the Chukchi Sea. This program is expected to be coordinated
by Olgoonik-Fairweather LLC (OFJV) during the 2011 open-water season.
The environmental studies program is not part of the Statoil site
survey and soil investigations program, but acoustic monitoring
equipment is planned to be deployed on and near Statoil leases and will
therefore collect additional data on the sounds produced by the 2011
activities. The program components include:
Acoustics Monitoring,
Fisheries Ecology,
Benthic Ecology,
Plankton Ecology,
Marine Mammal Surveys,
Seabird Surveys, and
Physical Oceanography.
The planned 2011 program will continue the acoustic monitoring
programs carried out in 2006-2010. A similar number of acoustic
recorders as deployed in past years will be distributed broadly across
the Chukchi lease area and nearshore environment. In past years,
clusters of recorders designed to localize marine mammal calls
originating within or nearby the clusters have been deployed on each of
the companies' prospects: Amundsen (Statoil), Burger (Shell), and
Klondike (CPAI). This year, recorders from the clusters are planned to
be relocated in a broader deployment on and around Hanna Shoal.
The recorders will be deployed in late July or mid-August and will
be retrieved in early to mid-October, depending on
[[Page 46744]]
ice conditions. The recorders will be AMAR and AURAL model acoustic
buoys set to record at 16 kHz sample rate. These are the same recorder
models and same sample rates that have been used for this program from
2006-2010. The broad area arrays are designed to capture general
background soundscape data, industrial sounds, and marine mammal call
data across the lease area. From previous deployments of these
recordings, industry has been able to gain insight into large-scale
distributions of marine mammals, identification of marine mammal
species present, movement and migration patterns, and general abundance
data.
Reporting Measures
(1) SSV Report
A report on the preliminary results of the acoustic verification
measurements, including as a minimum the measured 190-, 180-, 160-, and
120-dBrms re 1 [mu]Pa radii of the source vessel(s) and the
support vessels and the airgun array, will be submitted within 120 hr
after collection and analysis of those measurements at the start of the
field season. This report will specify the distances of the exclusion
zones that were adopted for the marine survey activities.
(2) Field Reports
Statoil states that throughout the survey program, the observers
will prepare a report each day or at such other interval as the IHA or
Statoil may require, summarizing the recent results of the monitoring
program. The field reports will summarize the species and numbers of
marine mammals sighted. These reports will be provided to NMFS and to
the survey operators.
(3) Technical Reports
The results of Statoil's 2011 vessel-based monitoring, including
estimates of ``take'' by harassment, will be presented in the ``90-
day'' and Final Technical reports. The Technical Reports will include:
(a) Summaries of monitoring effort (e.g., total hours, total
distances, and marine mammal distribution through the study period,
accounting for sea state and other factors affecting visibility and
detectability of marine mammals);
(b) Analyses of the effects of various factors influencing
detectability of marine mammals (e.g., sea state, number of observers,
and fog/glare);
(c) Species composition, occurrence, and distribution of marine
mammal sightings, including date, water depth, numbers, age/size/gender
categories (if determinable), group sizes, and ice cover;
(d) To better assess impacts to marine mammals, data analysis
should be separated into periods when a seismic airgun array (or a
single mitigation airgun) is operating and when it is not. Final and
comprehensive reports to NMFS should summarize and plot:
Data for periods when a seismic array is active and when
it is not; and
The respective predicted received sound conditions over
fairly large areas (tens of km) around operations;
(e) Sighting rates of marine mammals during periods with and
without airgun activities (and other variables that could affect
detectability), such as:
Initial sighting distances versus airgun activity state;
Closest point of approach versus airgun activity state;
Observed behaviors and types of movements versus airgun
activity state;
Numbers of sightings/individuals seen versus airgun
activity state;
Distribution around the survey vessel versus airgun
activity state; and
Estimates of take by harassment;
(f) Reported results from all hypothesis tests should include
estimates of the associated statistical power when practicable;
(g) Estimate and report uncertainty in all take estimates.
Uncertainty could be expressed by the presentation of confidence
limits, a minimum-maximum, posterior probability distribution, etc.;
the exact approach would be selected based on the sampling method and
data available;
(h) The report should clearly compare authorized takes to the level
of actual estimated takes; and
(i) As a starting point for integrating different data sources,
Statoil should present their 2010 and 2011 data by plotting acoustic
detections from bottom-mounted hydrophone and visual detections from
MMOs on a single map.
(4) Comprehensive Report
Following the 2011 open-water season, a comprehensive report
describing the vessel-based and acoustic monitoring programs will be
prepared. The comprehensive report will describe the methods, results,
conclusions and limitations of each of the individual data sets in
detail. The report will also integrate (to the extent possible) the
studies into a broad based assessment of industry activities, other
activities that occur in the Beaufort and/or Chukchi seas, and their
impacts on marine mammals during 2011. The report will help to
establish long-term data sets that can assist with the evaluation of
changes in the Chukchi and Beaufort Sea ecosystems. The report will
attempt to provide a regional synthesis of available data on industry
activity in offshore areas of northern Alaska that may influence marine
mammal density, distribution, and behavior.
(5) Notification of Injured or Dead Marine Mammals
In addition to the reporting measures proposed by Statoil, NMFS is
requiring Statoil to notify NMFS' Office of Protected Resources and
NMFS' Stranding Network within 48 hours of sighting an injured or dead
marine mammal in the vicinity of marine survey operations. Statoil
shall provide NMFS with the species or description of the animal(s),
the condition of the animal(s) (including carcass condition if the
animal is dead), location, time of first discovery, observed behaviors
(if alive), and photo or video (if available).
In the event that an injured or dead marine mammal is found by
Statoil that is not in the vicinity of the proposed open-water marine
survey program, Statoil will report the same information as listed
above as soon as operationally feasible to NMFS.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: any act of pursuit, torment, or
annoyance which (i) Has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment]. Only take by Level B behavioral
harassment is anticipated as a result of the proposed open-water marine
survey program. Anticipated impacts to marine mammals are associated
with noise propagation from the survey airgun(s) used in the shallow
hazards survey.
The full suite of potential impacts to marine mammals was described
in detail in the ``Potential Effects of the Specified Activity on
Marine Mammals'' section found in the Notice of Proposed IHA (76 FR
30110; May 24, 2011). The potential effects of sound from the open-
water marine survey programs might include one or more of the
following: tolerance; masking of natural sounds; behavioral
disturbance; non-auditory physical effects; and, at least in theory,
temporary or permanent hearing impairment (Richardson et al. 1995). As
[[Page 46745]]
discussed earlier in this document, the most common impact will likely
be from behavioral disturbance, including avoidance of the ensonified
area or changes in speed, direction, and/or diving profile of the
animal. For reasons discussed previously in this document, hearing
impairment (TTS and PTS) is highly unlikely to occur based on the
required mitigation and monitoring measures that would preclude marine
mammals being exposed to noise levels high enough to cause hearing
impairment.
For impulse sounds, such as those produced by airgun(s) used in the
shallow hazards survey, NMFS uses the 160 dBrms re 1 [mu]Pa
isopleth to indicate the onset of Level B harassment. For non-impulse
sounds, such as noise generated during the geotechnical soil
investigation that involves drilling bore holes and running the dynamic
positioning thruster of the vessel, NMFS uses the 120 dBrms
re 1 [mu]Pa isopleth to indicate the onset of Level B harassment.
Statoil provided calculations for the 160- and 120-dB isopleths
produced by these activities and then used those isopleths to estimate
takes by harassment. NMFS used the calculations to make the necessary
MMPA findings. Statoil provided a full description of the methodology
used to estimate takes by harassment in its IHA application (see
ADDRESSES), which was also provided in the Notice of Proposed IHA (76
FR 30110; May 24, 2011). A summary of that information is provided
here, as it has not changed from the proposed notice.
Statoil has requested an authorization to take 13 marine mammal
species by Level B harassment. These 13 marine mammal species are:
beluga whale (Delphinapterus leucas), narwhal (Monodon monoceros),
killer whale (Orcinus orca), harbor porpoise (Phocoena phocoena),
bowhead whale (Balaena mysticetus), gray whale (Eschrichtius robustus),
humpback whale (Megaptera novaeangliae), minke whale (Balaenoptera
acutorostrata), fin whale (B. physalus), bearded seal (Erignathus
barbatus), ringed seal (Phoca hispida), spotted seal (P. largha), and
ribbon seal (Histriophoca fasciata).
Basis for Estimating ``Take by Harassment''
As stated previously, it is current NMFS policy to estimate take by
Level B harassment for impulse sounds at a received level of 160
dBrms re 1[mu]Pa. However, not all animals react to sounds
at this low level, and many will not show strong reactions (and in some
cases any reaction) until sounds are much stronger. Southall et al.
(2007) provide a severity scale for ranking observed behavioral
responses of both free-ranging marine mammals and laboratory subjects
to various types of anthropogenic sound (see Table 4 in Southall et al.
(2007)). Tables 7, 9, and 11 in Southall et al. (2007) outline the
numbers of low-frequency cetaceans, mid-frequency cetaceans, and
pinnipeds in water, respectively, reported as having behavioral
responses to multi-pulses in 10-dB received level increments. These
tables illustrate that for the studies summarized the more severe
reactions did not occur until sounds were much higher than 160
dBrms re 1[mu]Pa.
As described earlier in the document, a 4 x 10 in\3\ airgun cluster
will be used to obtain geological data during the site surveys. A
similar airgun cluster was measured by Shell in 2009 during shallow
hazards surveys on their nearby Burger prospect (Reiser et al. 2010).
For use in estimating potential harassment takes in this application,
as well as for mitigation radii to be implemented by PSOs prior to SSV
measurements, ranges to threshold levels from the 2009 measurements
were increased by 25% as a precautionary approach (Table 1). The >= 160
dB distance is therefore estimated to be 2.25 km (1.4 mi) from the
source. Adding a 2.25 km (1.4 mi) perimeter to the two site survey
areas results in an estimated area of 1,037 km\2\ being exposed to
>=160 dB.
Geotechnical soil investigations on the Statoil leases and leases
jointly owned with CPAI will involve completing 3-4 boreholes at up to
8 total prospective drilling locations for an expected maximum of 29
boreholes. The 3-4 boreholes completed at each drilling location will
be positioned in a square or triangle formation, roughly 100 m (328 ft)
on each side. As described earlier, the sounds produced by soil
investigation equipment are estimated to fall below 120 dB at a
distance of 7.5 km (4.7 mi). Buffering 4 core sites spaced 100 m (328
ft) apart with the 7.5 km (4.7 mi) 120 dB distance results in a total
area of 180 km\2\. The total area exposed to sounds >= 120 dB by soil
investigations at the 8 prospective drilling locations will therefore
be 1,440 km\2\.
The following subsections summarize the estimated densities of
marine mammals that may occur in the areas where activities are planned
and areas of water that may be ensonified by pulsed sounds to >= 160 dB
or non-pulsed sounds to >= 120 dB.
Marine mammal densities near the planned activities in the Chukchi
Sea are likely to vary by season and habitat. Therefore, densities have
been derived for two time periods, the summer period, including 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 whether they are occurring in open
water or near the ice margin. Vessel and equipment limitations will
result in very little activity occurring in or near sea ice, however,
if ice is present near the areas of activity some sounds produced by
the activities may remain above disturbance threshold levels in ice
margin habitats. Therefore, open water densities have been used to
estimate potential ``take by harassment'' in 90% of the area expected
to be ensonified above disturbance thresholds while ice margin
densities have been used in the remaining 10% of the ensonified area.
Detectability bias [f(0)] is associated with diminishing
sightability with increasing lateral distance from the trackline.
Availability bias [g(0)] refers to the fact that there is < 100%
probability of sighting an animal that is present on the survey
trackline. Some sources of densities used included these correction
factors in their reported densities. In other cases the best available
correction factors were applied to reported results when they had not
been included in the reported analyses (e.g. Moore et al. 2000).
Tables 2 and 3 present the expected densities of marine mammals in
the planned survey area for both open-water and ice-margin habitat in
the summer and fall seasons, respectively.
(1) Cetaceans
Eight species of cetaceans are known to occur in the Chukchi Sea
area of the Statoil project. Only four of these (bowhead, beluga, and
gray whales, and harbor porpoise) are likely to be encountered during
the survey activities. Three of the eight species (bowhead, fin, and
humpback whales) are listed as endangered under the ESA. Of these, only
the bowhead is likely to be found within the survey area.
Beluga Whales--Summer densities of belugas in offshore waters of
the Chukchi Sea are expected to be low, with higher densities in ice-
margin and nearshore areas. Aerial surveys have recorded few belugas in
the offshore Chukchi Sea during the summer months (Moore et al. 2000).
Aerial surveys of the Chukchi Sea in 2008-2009 flown by the NMML as
part of the Chukchi Offshore Monitoring in Drilling Area project
(COMIDA) have only reported 5 beluga sightings during > 14,000 km of
on-transect effort, only 2 of which were
[[Page 46746]]
offshore (COMIDA 2009). 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 and Ferguson (in prep.) were used to calculate the average open-
water density estimate.
In the fall, beluga whale densities 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
2010). Densities derived from survey results in the northern Chukchi
Sea in Clarke and Ferguson (in prep.) were used as the average density
for open-water fall season estimates (see Table 3). Based on the lack
of any beluga sightings from vessels operating in the Chukchi Sea
during non-seismic periods and locations in September-October of 2006-
2008 (Haley et al. 2010), the relatively low densities shown in Table 3
are consistent with what is likely to be observed from vessels during
the planned operations.
Table 2--Expected Densities of Cetaceans and Seals in Areas of the
Chukchi Sea, Alaska, During the Planned Summer (July-August) Period of
the Shallow Hazards Survey Program
------------------------------------------------------------------------
Open water Ice margin
Species average density average density
(/km\2\) (/km\2\)
------------------------------------------------------------------------
Beluga whale.................... 0.0010 0.0040
Narwhal......................... 0.0000 0.0000
Killer whale.................... 0.0001 0.0001
Harbor porpoise................. 0.0011 0.0011
Bowhead whale................... 0.0013 0.0013
Fin whale....................... 0.0001 0.0001
Gray whale...................... 0.0258 0.0258
Humpback whale.................. 0.0001 0.0001
Minke whale..................... 0.0001 0.0001
Bearded seal.................... 0.0107 0.0142
Ribbon seal..................... 0.0005 0.0005
Ringed seal..................... 0.3668 0.4891
Spotted seal.................... 0.0073 0.0098
------------------------------------------------------------------------
Table 3-- Expected Densities of Cetaceans and Seals in Areas of the
Chukchi Sea, Alaska, During the Planned Fall (September-October) Period
of the Shallow Hazards Survey Program
------------------------------------------------------------------------
Open water Ice margin
Species average density average density
(/km\2\) (/km\2\)
------------------------------------------------------------------------
Beluga whale.................... 0.0015 0.0060
Narwhal......................... 0.0000 0.0000
Killer whale.................... 0.0001 0.0001
Harbor porpoise................. 0.0001 0.0001
Bowhead whale................... 0.0219 0.0438
Fin whale....................... 0.0001 0.0001
Gray whale...................... 0.0080 0.0080
Humpback whale.................. 0.0001 0.0001
Minke whale..................... 0.0001 0.0001
Bearded seal.................... 0.0107 0.0142
Ribbon seal..................... 0.0005 0.0005
Ringed seal..................... 0.2458 0.3277
Spotted seal.................... 0.0049 0.0065
------------------------------------------------------------------------
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. The estimate of summer bowhead whale density
in the Chukchi Sea was calculated by assuming there was one bowhead
sighting during the 11,985 km of survey effort in waters 36-50 m deep
in the Chukchi Sea during July-August reported in Clarke and Ferguson
(in prep.), although no bowheads were actually observed during those
surveys. Bowheads are not expected to be encountered in higher
densities near ice in the summer (Moore et al. 2000), so the same
density estimates are 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 2006-2008 (Haley et al.
2010) ranged from 0.0001-0.0007/km\2\ with a maximum 95 percent
confidence interval (CI) of 0.0029/km\2\. This suggests the densities
used in the calculations and shown in Table 3 are somewhat higher than
are likely to be observed from vessels near the area of planned
operations.
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 that bowheads will be encountered
in the Chukchi Sea at this time of year. 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). Clarke and
Ferguson (in prep.) reported 14 sightings (15 individuals) during
10,036 km of on transect aerial survey effort in
[[Page 46747]]
2008-2010. The mean group size from those sightings is 1.1. The same
f(0) and g(0) values that were used for the summer estimates above were
used for the fall estimates (Table 3). Moore et al. (2000) found that
Bowheads were detected more often than expected in association with ice
in the Chukchi Sea in September-October, so a density of twice the
average open-water density was used as the average ice-margin density
(Table 3). Densities from vessel based surveys in the Chukchi Sea
during non-seismic periods and locations in September-October of 2006-
2008 (Haley et al. 2010) ranged from 0.0003/km\2\ to 0.0044/km\2\ with
a maximum 95 percent CI of 0.0419 km\2\. This suggests the densities
used in the calculations and shown in Table 3 are somewhat higher than
are likely to be observed from vessels near the area of planned
operations.
Gray Whales--Gray whale densities are expected to be much higher in
the summer months than during the fall. The average open-water summer
density (Table 2) was calculated from effort and sightings reported by
Clarke and Ferguson (in prep.) for water depths 36-50 m including 54
sightings (73 individuals) during 11,985 km of on-transect effort. 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. 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 (15 sightings [19 individuals] during 10,036 km of on-
transect effort) in water 36-50 m deep during September-October
reported by Clarke and Ferguson (in prep.) was used as the average
estimate for the Chukchi Sea during the fall period (Table 3).
Harbor Porpoise--Harbor Porpoise densities were estimated from
industry data collected during 2006-2008 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-
2008, however, recorded sightings throughout the Chukchi Sea during the
summer and early fall months. Density estimates from 2006-2008
observations during non-seismic periods and locations in July-August
ranged from 0.0008/km\2\ to 0.0015/km\2\ with a maximum 95 percent CI
of 0.0079/km\2\ (Haley et al. 2010). The average of those three years
(0.0011/km\2\) was used as the average open-water density estimate
while the high value (0.0015/km\2\) was used as the maximum estimate
(Table 2). 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 2006-2008 were slightly lower
than the summer months and ranged from 0.0002/km\2\ to 0.0010/km\2\
with a maximum 95 percent CI of 0.0093/km\2\. The average of those
three years (0.0001/km\2\) was again used as the average density
estimate and the high value 0.0011/km\2\ was used as the maximum
estimate (Table 3).
Other Cetaceans--The remaining five cetacean species that could be
encountered in the Chukchi Sea during Statoil's planned activities
include the humpback whale, killer whale, minke whale, fin whale, and
narwhal. Although there is evidence of the occasional occurrence of
these animals in the Chukchi Sea, it is unlikely that more than a few
individuals will be encountered during the planned activities. George
and Suydam (1998) reported killer whales, Brueggeman et al. (1990) and
Haley et al. (2010) reported minke whale, and COMIDA (2009) and Haley
et al. (2010) reported fin whales. Narwhal sightings in the Chukchi Sea
have not been reported in recent literature, but subsistence hunters
occasionally report observations near Barrow, and Reeves et al. (2002)
indicated a small number of extralimital sightings in the Chukchi Sea.
(2) Pinnipeds
Four species of pinnipeds may be encountered in the Chukchi Sea:
Ringed seal, bearded seal, spotted seal, and ribbon seal. Each of these
species, except the spotted seal, is associated with both the ice
margin and the nearshore area. The ice margin is considered preferred
habitat (as compared to the nearshore areas) during most seasons.
Ringed and Bearded Seals--Ringed seal and bearded seal summer ice-
margin densities (Table 2) were taken from Bengtson et al. (2005) who
conducted spring surveys in the offshore pack ice zone (zone 12P) of
the northern Chukchi Sea. However, a correction for bearded seal
availability bias, g(0), based on haulout and diving patterns was not
available and used in the reported densities. 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 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.
Spotted Seal--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.
Ribbon Seal--Two ribbon seal sightings were reported during
industry vessel operations in the Chukchi Sea in 2006-2008 (Haley et
al. 2010). The resulting density estimate of 0.0005/km\2\ was used as
the average density.
Potential Number of Takes by Harassment
This subsection provides estimates of the number of individuals
potentially exposed to sound levels >= 160 dBrms re 1 [mu]Pa
by pulsed airgun sounds and to >= 120 dBrms re 1 [mu]Pa by
non-impulse sounds during geotechnical soil investigations. The
estimates are based on a consideration of the number of marine mammals
that might be disturbed appreciably by operations in the Chukchi Sea
and the anticipated area exposed to those sound levels.
The number of individuals of each species potentially exposed to
received levels of pulsed sounds >= 160 dBrms re 1 [mu]Pa or
to >= 120 dBrms re 1 [mu]Pa by continuous sounds within each
season and habitat zone was estimated by multiplying:
The anticipated area to be ensonified to the specified
level in each season and habitat zone to which that density applies, by
The expected species density.
The numbers of individuals potentially exposed were then summed for
each species across the two seasons and habitat zones. Some of the
animals estimated to be exposed, particularly migrating bowhead whales,
might show avoidance reactions before being exposed to pulsed airgun
sounds >= 160 dBrms re 1 [mu]Pa. Thus, these calculations
actually estimate the number of individuals potentially exposed to the
specified sound levels that would occur
[[Page 46748]]
if there were no avoidance of the area ensonified to that level.
Site survey and geotechnical soil investigations are planned to
occur primarily in August and September, with the potential to continue
into mid-November, if necessary and weather permitting. For the
purposes of assigning activities to the summer (August) and fall
(September-October) periods for which densities have been estimated
above, NMFS has assumed that half of the operations will occur during
the summer period and half will occur in the fall period. Additionally,
the planned activities cannot be completed in or near significant
amounts of sea ice, so 90% of the activity each season (and associated
ensonified areas) has been multiplied by the open-water densities
described above, while the remaining 10% of activity has been
multiplied by the ice-margin densities.
Species with an estimated average number of individuals exposed
equal to zero are included below for completeness, but are not likely
to be encountered.
(1) Shallow Hazards and Site Clearance Surveys
The estimated numbers of marine mammals potentially exposed to
airgun sounds with received levels >= 160 dBrms from site
surveys on Statoil's leases are shown in Table 4. The average estimate
of the number of individual bowhead whales exposed to received sound
levels >= 160 dB is 11. The average estimate for gray whales is
slightly greater at 18, while few belugas are expected to be exposed
(Table 4). Few other cetaceans (such as narwhal, harbor porpoise,
killer, humpback, fin, and minke whales) are likely to be exposed to
airgun sounds >= 160 dB, but estimates have been included to account
for chance encounters.
Ringed seals are expected to be the most abundant animal in the
Chukchi Sea during this period, and the average estimate of the number
exposed to >= 160 dB by site survey activities is 337 (Table 4).
Estimated exposures of other seal species are substantially below those
for ringed seals (Table 4).
Table 4--Summary of the Number of Marine Mammals in Areas Where Maximum Received Sound Levels in the Water Would
Be >= 160 dB in Summer (Aug) and Fall (Sep-Oct) Periods During Statoil's Planned Site Surveys in the Chukchi
Sea, Alaska. Not All Marine Mammals Are Expected To Change Their Behavior When Exposed to These Sound Levels
----------------------------------------------------------------------------------------------------------------
Number of individuals exposed to sound levels >= 160 dB
-------------------------------------------------------------------------------
Species Summer Fall
---------------------------------------------------------------- Total
Open water Ice margin Open water Ice margin
----------------------------------------------------------------------------------------------------------------
Beluga whale.................... 0 0 1 0 2
Narwhal......................... 0 0 0 0 2
Killer whale.................... 0 0 0 0 2
Harbor porpoise................. 1 0 0 0 1
Bowhead whale................... 1 0 10 0 11
Gray whale...................... 12 1 4 1 18
Humpback whale.................. 0 0 0 0 2
Fin whale....................... 0 0 0 0 2
Minke whale..................... 0 0 0 0 2
Bearded seal.................... 5 1 5 1 12
Ribbon seal..................... 0 0 0 0 1
Ringed seal..................... 171 25 115 25 337
Spotted seal.................... 3 1 2 1 7
----------------------------------------------------------------------------------------------------------------
(2) Geotechnical Soil Investigations
The estimated numbers of marine mammals potentially exposed to
continuous sounds with received levels >= 120 dBrms from
geotechnical soil investigations on Statoil's leases and jointly owned
leases are shown in Table 5. The average estimate of the number of
individual bowhead whales exposed to received sound levels >= 120 dB is
15. The average estimate for gray whales is slightly larger at 26
individuals (Table 5). Few other cetaceans (such as narwhal, harbor
porpoise, killer, humpback, fin, and minke whales) are likely to be
exposed to soil investigation sounds >= 120 dB, but estimates have been
included to account for chance encounters.
The average estimate of the number of ringed seals potentially
exposed to >= 120 dB by soil investigation activities is 467 (Table 5).
Estimated exposures of other seal species are substantially below those
for ringed seals (Table 5).
Table 5--Summary of the Number of Marine Mammals in Areas Where Maximum Received Sound Levels in the Water Would
Be >= 120 dB in Summer (Aug) and Fall (Sep-Oct) Periods During Statoil's Planned Geotechnical Soil
Investigations in the Chukchi Sea, Alaska. Not All Marine Mammals Are Expected To Change Their Behavior When
Exposed to These Sound Levels
----------------------------------------------------------------------------------------------------------------
Number of individuals exposed to sound levels >= 120 dB
-------------------------------------------------------------------------------
Species Summer Fall
---------------------------------------------------------------- Total
Open water Ice margin Open water Ice margin
----------------------------------------------------------------------------------------------------------------
Beluga whale.................... 1 0 1 0 2
Narwhal......................... 0 0 0 0 3
Killer whale.................... 0 0 0 0 3
Harbor porpoise................. 1 0 0 0 1
[[Page 46749]]
Bowhead whale................... 1 0 14 0 15
Gray whale...................... 17 2 5 2 26
Humpback whale.................. 0 0 0 0 3
Fin whale....................... 0 0 0 0 3
Minke whale..................... 0 0 0 0 3
Bearded seal.................... 7 1 7 1 16
Ribbon seal..................... 0 0 0 0 1
Ringed seal..................... 238 35 159 35 467
Spotted seal.................... 5 1 3 1 10
----------------------------------------------------------------------------------------------------------------
Estimated Take Conclusions
Cetaceans--Effects on cetaceans are generally expected to be
restricted to avoidance of an area around the seismic survey and short-
term changes in behavior, falling within the MMPA definition of ``Level
B harassment''.
Using the 160 and 120 dB criteria, the average estimates of the
numbers of individual cetaceans exposed to received levels higher than
these sound pressure levels represent varying proportions of the
populations of each species in the Beaufort Sea and adjacent waters.
For species listed as ``Endangered'' under the ESA, the estimates
include approximately 26 bowheads. This number is approximately 0.18%
of the Bering-Chukchi-Beaufort population of > 14,247 assuming 3.4%
annual population growth from the 2001 estimate of > 10,545 animals
(Zeh and Punt 2005). For other cetaceans that might occur in the
vicinity of the shallow hazards survey in the Chukchi Sea, they also
represent a very small proportion of their respective populations. The
average estimates of the number of belugas, killer whales, harbor
porpoises, gray whales, humpback whales, fin whales, and minke whales
that might be exposed to >=160 dB and 120 dB re 1 [mu]Pa are 4, 5, 2,
44, 5, 5, and 5. These numbers represent 0.11%, 1.59%, 0.004%, 0.25%,
0.53%, 0.09%, and 0.50% of these species of their respective
populations in the proposed action area. No population estimates of
narwhal are available in U.S. waters due to its extralimital
distribution here. The world population of narwhal is estimated at
75,000 (Laidre et al. 2008), and most of them are concentrated in the
fjords and inlets of Northern Canada and western Greenland. The
estimated take of 5 narwhals represents approximately 0.01% of its
population.
Seals--A few seal species are likely to be encountered in the study
area, but ringed seal is by far the most abundant in this area. The
average estimates of the numbers of individuals exposed to sounds at
received levels = 160 and 120 dBrms re 1 [mu]Pa
during the proposed shallow hazards survey and geotechnical soil
investigation are as follows: Ringed seals (803), bearded seals (28),
spotted seals (17), and ribbon seals (2). These numbers represent
0.35%, 0.01%, 0.03%, and 0.002% of Alaska stocks of ringed, bearded,
spotted, and ribbon seals, respectively.
Negligible Impact and Small Numbers Analysis and Determination
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``* * *
an impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.'' In making a negligible impact determination,
NMFS considers a variety of factors, including but not limited to: (1)
The number of anticipated mortalities; (2) the number and nature of
anticipated injuries; (3) the number, nature, intensity, and duration
of Level B harassment; and (4) the context in which the takes occur.
No injuries or mortalities are anticipated to occur as a result of
Statoil's proposed 2011 open water marine shallow hazards surveys in
the Chukchi Seas, and none are authorized. In addition, these surveys
would use a small 40 in\3\ airgun array and several mid- to high-
frequency active acoustic sources. The acoustic power output is much
lower than full scale airgun arrays used in a 2D or 3D seismic survey
and thus generates much lower source levels. The modeled isopleths at
160 dB is expected to be less than 2.25 km (1.4 mi) from the airgun
source (see discussion earlier). Additionally, animals in the area are
not expected to incur hearing impairment (i.e., TTS or PTS) or non-
auditory physiological effects. Takes will be limited to Level B
behavioral harassment. Although it is possible that some individuals of
marine mammals may be exposed to sounds from shallow hazards survey
activities more than once, the expanse of these multi-exposures are
expected to be less extensive since both the animals and the survey
vessels will be moving constantly in and out of the survey areas.
Most of the bowhead whales encountered during the summer will
likely show overt disturbance (avoidance) only if they receive airgun
sounds with levels >= 160 dB re 1 [mu]Pa. Odontocete reactions to
seismic energy pulses are usually assumed to be limited to shorter
distances from the airgun(s) than are those of mysticetes, probably in
part because odontocete low-frequency hearing is assumed to be less
sensitive than that of mysticetes. However, at least when in the
Canadian Beaufort Sea in summer, belugas appear to be fairly responsive
to seismic energy, with few being sighted within 6-12 mi (10-20 km) of
seismic vessels during aerial surveys (Miller et al. 2005). Belugas
will likely occur in small numbers in the Chukchi Sea during the survey
period, and few will likely be affected by the survey activity. In
addition, due to the constant moving of the survey vessel, the duration
of the noise exposure by cetaceans to seismic impulse would be brief.
For the same reason, it is unlikely that any individual animal would be
exposed to high received levels multiple times.
[[Page 46750]]
For animals exposed to machinery noise from geotechnical soil
investigations, NMFS considers that at received levels >= 120 dB re 1
[mu]Pa, the animals could respond behaviorally in a manner that NMFS
considers Level B harassment due to the non-pulse nature of the noise
involved in this activity. During soil investigation operations, the
most intensive noise source is from the DP system that automatically
controls and coordinates vessel movements using bow and/or stern
thrusters. Measurements of a similar vessel in DP mode in the Chukchi
Sea in 2010 provided an estimated source level at about 176 dB re 1
[mu]Pa, which is below what NMFS uses to assess Level A harassment of
received levels at 180 dB for cetaceans and 190 dB for pinnipeds.
Therefore, no hearing impairment is anticipated. In addition, the
duration of the entire geotechnical soil investigation is approximately
14 days, and DP will only be running sporadically when needed to
position the vessel. In addition, the soil investigation operations are
expected to be stationary, with limited area to be ensonified.
Therefore, the impacts to marine mammals in the vicinity of the soil
investigation operations are expected to be in short duration and
localized.
Taking into account the mitigation measures that are required to be
implemented, effects on cetaceans are generally expected to be
restricted to avoidance of a limited area around the survey operation
and short-term changes in behavior, falling within the MMPA definition
of ``Level B harassment''. Furthermore, the estimated numbers of
animals potentially exposed to sound levels sufficient to cause
appreciable disturbance are very low percentages of the population
sizes in the Bering-Chukchi-Beaufort seas, as described above.
The many reported cases of apparent tolerance by cetaceans of
seismic exploration, vessel traffic, and some other human activities
show that co-existence is possible. Mitigation measures such as
controlled vessel speed, dedicated PSOs, non-pursuit, and shut downs or
power downs when marine mammals are seen within defined ranges, will
further reduce short-term reactions and minimize any effects on hearing
sensitivity. In all cases, the effects are expected to be short-term,
with no lasting biological consequence.
Some individual pinnipeds may be exposed to sound from the marine
surveys more than once during the time frame of the project. However,
as discussed previously, due to the constant moving of the survey
vessel, the probability of an individual pinniped being exposed to
sound multiple times is much lower than if the source is stationary.
Therefore, NMFS has determined that the exposure of pinnipeds to sounds
produced by the shallow hazards surveys and soil investigation in the
Chukchi Sea is not expected to result in more than Level B harassment
and is anticipated to have no more than a negligible impact on the
animals.
Of the thirteen marine mammal species likely to occur in the marine
survey area, only the bowhead, fin, and humpback whales are listed as
endangered under the ESA. These species are also designated as
``depleted'' under the MMPA. Despite these designations, the Bering-
Chukchi-Beaufort stock of bowheads has been increasing at a rate of 3.4
percent annually for nearly a decade (Allen and Angliss 2010).
Additionally, during the 2001 census, 121 calves were counted, which
was the highest yet recorded. The calf count provides corroborating
evidence for a healthy and increasing population (Allen and Angliss
2010). The occurrence of fin and humpback whales in the marine survey
areas is considered very rare. There is no critical habitat designated
in the U.S. Arctic for the bowhead, fin, and humpback whale. On
December 10, 2010, NMFS published a notification of proposed threatened
status for subspecies of the ringed seal (75 FR 77476) and a
notification of proposed threatened and not warranted status for
subspecies and distinct population segments of the bearded seal (75 FR
77496) in the Federal Register. Neither species is considered depleted
under the MMPA. The listing for these species is not anticipated to be
completed prior to the end of this proposed seismic survey. None of the
other species that may occur in the project area are listed as
threatened or endangered under the ESA or designated as depleted under
the MMPA.
Potential impacts to marine mammal habitat were discussed
previously in this document (see the ``Anticipated Effects on Habitat''
section). Although some disturbance is possible to food sources of
marine mammals, the impacts are anticipated to be minor enough as to
not affect rates of recruitment or survival of marine mammals in the
area. Based on the vast size of the Arctic Ocean where feeding by
marine mammals occurs versus the localized area of the marine survey
activities, any missed feeding opportunities in the direct project area
would be minor based on the fact that other feeding areas exist
elsewhere.
The estimated authorized takes represent 0.11% of the Eastern
Chukchi Sea population of approximately 3,710 beluga whales (Allen and
Angliss 2010), 1.59% of Aleutian Island and Bering Sea stock of
approximately 314 killer whales, 0.004% of Bering Sea stock of
approximately 48,215 harbor porpoises, 0.25% of the Eastern North
Pacific stock of approximately 17,752 gray whales, 0.18% of the Bering-
Chukchi-Beaufort population of 14,247 bowhead whales assuming 3.4
percent annual population growth from the 2001 estimate of 10,545
animals (Zeh and Punt, 2005), 0.53% of the Western North Pacific stock
of approximately 938 humpback whales, 0.09% of the North Pacific stock
of approximately 5,700 fin whales, and 0.50% of the Alaska stock of
approximately 1,003 minke whales. The take estimates presented for
bearded, ringed, spotted, and ribbon seals represent 0.01, 0.35, 0.03,
and 0.002 percent of U.S. Arctic stocks of each species, respectively.
These estimates represent the percentage of each species or stock that
could be taken by Level B behavioral harassment if each animal is taken
only once. In addition, the mitigation and monitoring measures
(described previously in this document) required in the IHA are
expected to reduce even further any potential disturbance to marine
mammals.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the mitigation and monitoring
measures, NMFS finds that Statoil's 2011 open-water shallow hazards
survey in the Chukchi Sea may result in the incidental take of small
numbers of marine mammals, by Level B harassment only, and that the
total taking from the marine surveys will have a negligible impact on
the affected species or stocks.
Impact on Availability of Affected Species or Stock for Taking for
Subsistence Uses
Relevant Subsistence Uses
The disturbance and potential displacement of marine mammals by
sounds from the proposed marine surveys are the principal concerns
related to subsistence use of the area. Subsistence remains the basis
for Alaska Native culture and community. Subsistence hunting and
fishing continue to be prominent in the household economies and social
welfare of some Alaskan residents, particularly among those living in
small, rural
[[Page 46751]]
villages (Wolfe and Walker 1987). In rural Alaska, subsistence
activities are often central to many aspects of human existence,
including patterns of family life, artistic expression, and community
religious and celebratory activities. Additionally, the animals taken
for subsistence provide a significant portion of the food that will
last the community throughout the year. The main species that are
hunted include bowhead and beluga whales, ringed, spotted, and bearded
seals, walruses, and polar bears. (Both the walrus and the polar bear
are under the USFWS' jurisdiction.) The importance of each of these
species varies among the communities and is largely based on
availability.
Bowhead whales, belugas, and walruses are the marine mammal species
primarily harvested during the time of Statoil's shallow hazards
survey. There is little or no bowhead hunting by the community of Point
Lay, so beluga and walrus hunting are of more importance there. Members
of the Wainwright community hunt bowhead whales in the spring, although
bowhead whale hunting conditions there are often more difficult than
elsewhere, and they do not hunt bowheads during seasons when Statoil's
survey operation would occur. Depending on the level of success during
the spring bowhead hunt, Wainwright residents may be very dependent on
the presence of belugas in a nearby lagoon system during July and
August. Barrow residents focus hunting efforts on bowhead whales during
the spring and generally do not hunt beluga then. However, Barrow
residents also hunt in the fall, when Statoil expects to be conducting
shallow hazards surveys (though not near Barrow).
(1) Bowhead Whales
Bowhead whale hunting is a key activity in the subsistence
economies of northwest Arctic communities. An overall quota system for
the hunting of bowhead whales was established by the International
Whaling Commission (IWC) in 1977. The quota is now regulated through an
agreement between NMFS and the AEWC. The AEWC allots the number of
bowhead whales that each whaling community may harvest annually (USDI/
BLM 2005). The annual take of bowhead whales has varied due to (a)
Changes in the allowable quota level and (b) year-to-year variability
in ice and weather conditions, which strongly influence the success of
the hunt.
Bowhead whales migrate around northern Alaska twice each year,
during the spring and autumn, and are hunted in both seasons. Bowhead
whales are hunted from Barrow during the spring, and the fall migration
and animals are not successfully harvested every year. The spring hunt
along Chukchi villages and at Barrow occurs after leads open due to the
deterioration of pack ice; the spring hunt typically occurs from early
April until the first week of June. The fall migration of bowhead
whales that summer in the eastern Beaufort Sea typically begins in late
August or September. Fall migration into Alaskan waters is primarily
during September and October.
In the fall, subsistence hunters use aluminum or fiberglass boats
with outboards. Hunters prefer to take bowheads close to shore to avoid
a long tow during which the meat can spoil, but Braund and Moorehead
(1995) report that crews may (rarely) pursue whales as far as 50 mi (80
km). The autumn bowhead hunt usually begins in Barrow in mid-September,
and mainly occurs in the waters east and northeast of Point Barrow.
The scheduling of this shallow hazard survey has been discussed
with representatives of those concerned with the subsistence bowhead
hunt, most notably the AEWC, the Barrow Whaling Captains' Association,
and the North Slope Borough (NSB) Department of Wildlife Management.
The planned mobilization and start date for shallow hazards surveys
in the Chukchi Sea (~25 July and ~1 August, respectively) is well after
the end of the spring bowhead migration and hunt at Wainwright and
Barrow. Shallow hazards survey and soil investigation operations will
be conducted far offshore from Barrow and Wainwright and are not
expected to conflict with subsistence hunting activities. Specific
concerns of the Barrow whaling captains are addressed as part of the
Plan of Cooperation discussed below.
(2) Beluga Whales
Beluga whales are available to subsistence hunters along the coast
of Alaska in the spring when pack-ice conditions deteriorate and leads
open up. Belugas may remain in coastal areas or lagoons through June
and sometimes into July and August. The community of Point Lay is
heavily dependent on the hunting of belugas in Kasegaluk Lagoon for
subsistence meat. From 1983-1992 the average annual harvest was ~40
whales (Fuller and George 1997). In Wainwright and Barrow, hunters
usually wait until after the spring bowhead whale hunt is finished
before turning their attention to hunting belugas. The average annual
harvest of beluga whales taken by Barrow for 1962-1982 was five (MMS
1996). The Alaska Beluga Whale Committee recorded that 23 beluga whales
had been harvested by Barrow hunters from 1987 to 2002, ranging from 0
in 1987, 1988 and 1995 to the high of 8 in 1997 (Fuller and George
1997; Alaska Beluga Whale Committee 2002 in USDI/BLM 2005). The seismic
survey activities take place well offshore, far away from areas that
are used for beluga hunting by the Chukchi Sea communities.
Additionally, Statoil's mobilization date is after the usual completion
date of the spring beluga hunt in Kasegaluk Lagoon (i.e., July 15 for
end date of the hunt).
(3) Ringed Seals
Ringed seals are hunted mainly from October through June. Hunting
for these smaller mammals is concentrated during winter because bowhead
whales, bearded seals, and caribou are available during other seasons.
In winter, leads and cracks in the ice off points of land and along the
barrier islands are used for hunting ringed seals. The average annual
ringed seal harvest was 49 seals in Point Lay, 86 in Wainwright, and
394 in Barrow (Braund et al. 1993; USDI/BLM 2003; 2005). Although
ringed seals are available year-round, the planned activities will not
occur during the primary period when these seals are typically
harvested. Also, the activities will be largely in offshore waters
where the activities will not influence ringed seals in the nearshore
areas where they are hunted.
(4) Spotted Seals
The spotted seal subsistence hunt peaks in July and August along
the shore where the seals haul out but usually involves relatively few
animals. Spotted seals typically migrate south by October to overwinter
in the Bering Sea. During the fall migration, spotted seals are hunted
by the Wainwright and Point Lay communities as the seals move south
along the coast (USDI/BLM 2003). Spotted seals are also occasionally
hunted in the area off Point Barrow and along the barrier islands of
Elson Lagoon to the east (USDI/BLM 2005). The planned activities will
remain offshore of the coastal harvest area of these seals and should
not conflict with harvest activities.
(5) Bearded Seals
Bearded seals, although generally not favored for their meat, are
important to subsistence activities in Barrow and Wainwright, because
of their skins. Six to nine bearded seal hides are used by whalers to
cover each of the skin-covered boats traditionally used for spring
whaling. Because of their valuable hides and large size, bearded seals
are specifically sought. Bearded
[[Page 46752]]
seals are harvested during the spring and summer months in the Chukchi
Sea (USDI/BLM 2003; 2005). The animals inhabit the environment around
the ice floes in the drifting nearshore ice pack, so hunting usually
occurs from boats in the drift ice. Most bearded seals are harvested in
coastal areas inshore of the survey, so no conflicts with the harvest
of bearded seals are expected.
In the event that both marine mammals and hunters are near the
areas of planned operations, the project potentially could impact the
availability of marine mammals for harvest in a small area immediately
around the vessel, in the case of pinnipeds, and possibly in a large
area in the case of migrating bowheads. However, the majority of marine
mammals are taken by hunters within ~21 mi (~33 km) from shore, and the
survey activities will occur far offshore, well outside the hunting
areas. Considering the timing and location of the shallow hazards
survey activities, as described earlier in the document, the project is
not expected to have any significant impacts to the availability of
marine mammals for subsistence harvest. Specific concerns of the
respective communities are addressed as part of the Plan of Cooperation
between Statoil and the AEWC.
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 Statoil's open-water shallow
hazards survey have the potential to impact marine mammals hunted by
Native Alaskans. In the case of cetaceans, the most common reaction to
anthropogenic sounds (as noted previously in this document) is
avoidance of the ensonified area. In the case of bowhead whales, this
often means that the animals divert from their normal migratory path by
several kilometers. Additionally, general vessel presence in the
vicinity of traditional hunting areas could negatively impact a hunt.
In the case of subsistence hunts for bowhead whales in the Chukchi
Sea, there could be an adverse impact on the hunt if the whales were
deflected seaward (further from shore) in traditional hunting areas.
The impact would be that whaling crews would have to travel greater
distances to intercept westward migrating whales, thereby creating a
safety hazard for whaling crews and/or limiting chances of successfully
striking and landing bowheads.
In addition, Native knowledge indicates that bowhead whales become
increasingly ``skittish'' in the presence of seismic noise. Whales are
more wary around the hunters and tend to expose a much smaller portion
of their back when surfacing (which makes harvesting more difficult).
Additionally, natives report that bowheads exhibit angry behaviors in
the presence of seismic, such as tail-slapping, which translate to
danger for nearby subsistence harvesters.
Plan of Cooperation (POC or Plan)
Regulations at 50 CFR 216.104(a)(12) require IHA applicants for
activities that take place in Arctic waters to provide a POC or
information that identifies what measures have been taken and/or will
be taken to minimize adverse effects on the availability of marine
mammals for subsistence purposes.
Statoil states that it intends to maintain an open and transparent
process with all stakeholders throughout the life-cycle of activities
in the Chukchi Sea. Statoil began the stakeholder engagement process in
2009 with meeting Chukchi Sea community leaders at the tribal, city,
and corporate level. Statoil will continue to engage with leaders,
community members, and subsistence groups, as well as local, state, and
federal regulatory agencies throughout the exploration and development
process.
As part of stakeholder engagement, Statoil developed a POC for the
2011 activities. The POC summarizes the actions Statoil will take to
identify important subsistence activities, inform subsistence users of
the proposed survey activities, and obtain feedback from subsistence
users regarding how to promote cooperation between subsistence
activities and the Statoil program.
During the early phase of the POC process for the project, Statoil
met with the North Slope Borough Department of Wildlife Management (Dec
2010) and the AEWC (mini-convention in Barrow, Feb 2011). Statoil also
arranged to visit and hold public meetings in the affected Chukchi Sea
villages, including Pt. Hope, Pt. Lay, Wainwright, and Barrow during
the week of March 21, 2011.
Based upon these meetings, a final POC that documents all
consultations with community leaders, subsistence user groups,
individual subsistence users, and community members was submitted to
NMFS on July 14, 2011. Subsistence mitigation measures that Statoil
will implement during the shallow hazards survey program were described
in the Mitigation Measures section earlier in this document.
Unmitigable Adverse Impact Analysis and Determination
NMFS has determined that Statoil's proposed 2011 open water shallow
hazards survey in the Chukchi Sea will not have an unmitigable adverse
impact on the availability of species or stocks for taking for
subsistence uses. This determination is supported by information
contained in this document and Statoil's POC. Statoil has adopted a
spatial and temporal strategy for its Chukchi Sea operations that
should minimize impacts to subsistence hunters. Statoil will enter the
Chukchi Sea far offshore, so as to not interfere with July hunts in the
Chukchi Sea villages, if they are still ongoing. After the close of the
July beluga whale hunts in the Chukchi Sea villages, very little
whaling occurs in Wainwright, Point Hope, and Point Lay. Although the
fall bowhead whale hunt in Barrow will occur while Statoil is still
operating (mid- to late September to October), Barrow is approximately
150 mi (241 km) east of the eastern boundary of the shallow hazards
survey site. Because the whales are migrating westward from the
Canadian Beaufort Sea, they will reach Barrow before entering the area
of Statoil's activities. Based on these factors, Statoil's Chukchi Sea
shallow hazards survey is not expected to interfere with the fall
bowhead harvest in Barrow. In recent years, bowhead whales have
occasionally been taken in the fall by coastal villages along the
Chukchi coast, but the total number of these animals has been small.
Adverse impacts are not anticipated on sealing activities since the
majority of hunts for seals occur in the winter and spring, when
Statoil will not be operating. Additionally, most sealing activities
occur much closer to shore than Statoil's shallow hazards survey area.
Based on the measures described in Statoil's POC, mitigation and
monitoring measures (described earlier in this document), and the
project design itself, NMFS has determined that there will not be an
unmitigable adverse impact on subsistence uses of marine mammals from
Statoil's open-water
[[Page 46753]]
shallow hazards survey in the Chukchi Sea.
Endangered Species Act (ESA)
There are three marine mammal species listed as endangered under
the ESA with confirmed or possible occurrence in the project area: The
bowhead, humpback, and fin whales. NMFS' Permits, Conservation and
Education Division consulted with NMFS' Protected Resources Division
under section 7 of the ESA on the issuance of an IHA to Statoil under
section 101(a)(5)(D) of the MMPA for this activity. A Biological
Opinion was issued on July 22, 2011, which concludes that issuance of
an IHA is not likely to jeopardize the continued existence of the fin,
humpback, or bowhead whale. NMFS has issued an Incidental Take
Statement under this Biological Opinion which contains reasonable and
prudent measures with implementing terms and conditions to minimize the
effects of take of listed species.
National Environmental Policy Act (NEPA)
In 2010, NMFS prepared an EA and issued FONSIs for open-water
seismic and marine surveys in the Beaufort and Chukchi seas by Shell
and Statoil. A review of Statoil's proposed 2011 open-water shallow
hazards surveys indicates that the planned action is essentially the
same as the marine survey conducted by Shell in 2010, but on a smaller
scale. In addition, the review indicated that there is no significant
change in the environmental baselines from those analyzed in 2010.
Therefore, NMFS has prepared a Supplemental EA which incorporates by
reference the 2010 EA and other related documents and updates the
activity to reflect the lower impacts compared to the previous season.
A FONSI was issued for this action on July 21, 2011. Therefore,
preparation of an EIS is not necessary.
Authorization
As a result of these determinations, NMFS has issued an IHA to
Statoil to take marine mammals incidental to its 2011 open-water
shallow hazards and geotechnical surveys in the Chukchi Sea, Alaska,
provided the previously mentioned mitigation, monitoring, and reporting
requirements are incorporated.
Dated: July 28, 2011.
Helen Golde,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2011-19663 Filed 8-2-11; 8:45 am]
BILLING CODE 3510-22-P