[Federal Register Volume 66, Number 156 (Monday, August 13, 2001)]
[Notices]
[Pages 42515-42523]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-20281]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 072301F]
Small Takes of Marine Mammals Incidental to Specified Activities;
Seismic Activities in the Beaufort Sea
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of issuance of an incidental harassment authorization.
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SUMMARY: In accordance with provisions of the Marine Mammal Protection
Act (MMPA) as amended, notification is hereby given that an Incidental
Harassment Authorization (IHA) to take small numbers of bowhead whales
and other marine mammals by harassment incidental to conducting ocean
bottom cable (OBC) seismic surveys in the Alaskan Beaufort Sea, has
been issued to WesternGeco, LLC (formerly Western Geophysical) for the
open water period of 2001.
DATES: Effective from July 31, 2001, until November 1, 2001.
ADDRESSES: The application, authorization, monitoring plan, Biological
Opinion, and a list of references used in this document are available
by writing to Donna Wieting, Chief, Marine Mammal Conservation
[[Page 42516]]
Division, Office of Protected Resources, NMFS, 1315 East-West Highway,
Silver Spring, MD 20910-3225, or by telephoning one of the contacts
listed here.
FOR FURTHER INFORMATION CONTACT: Simona Perry Roberts, Office of
Protected Resources (301) 713-2322, ext. 106, or Brad Smith, Alaska
Region (907) 271-5006.
SUPPLEMENTARY INFORMATION:
Background
Sections 101 (a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, notice of a proposed authorization is
provided to the public for review.
Permission may be granted if NMFS finds that the taking will have
no more than a negligible impact on the species or stock(s) and will
not have an unmitigable adverse impact on the availability of the
species or stock(s) for subsistence uses and that the permissible
methods of taking and requirements pertaining to the monitoring and
reporting of such taking are set forth.
On April 10, 1996 (61 FR 15884), NMFS published an interim rule
establishing, among other things, procedures for issuing incidental
harassment authorizations (IHAs) under section 101 (a)(5)(D) of the
MMPA for activities in Arctic waters. For additional information on the
procedures to be followed for this authorization, please refer to 50
CFR 216.107.
Summary of Request
On April 16, 2001, NMFS received an application from WesternGeco
requesting an authorization for the harassment of small numbers of
several species of marine mammals incidental to conducting OBC seismic
surveys during the open water season in the south central Beaufort Sea
off Alaska between western Camden Bay and Harrison Bay. The primary
area of seismic activity is expected to be an area approximately 16 by
7 kilometers (km) (10 miles (mi) by 4 mi) in and near Simpson Lagoon,
west of Prudhoe Bay and offshore of Oliktok Point. Weather permitting,
the survey is expected to take place between approximately July 27 and
mid- to late-October, 2001.
WesternGeco's OBC survey involves dropping cables from a ship to
the ocean bottom, forming a patch consisting of 4 parallel cables 8.9
km (5.5 mi) long, separated by approximately 600 meters (m) (1,968 feet
(ft)) from each other. Hydrophones and geophones, attached to the
cables, are used to detect seismic energy reflected back from rock
strata below the ocean bottom. The source of this energy is a submerged
acoustic source, called a seismic airgun array, that releases
compressed air into the water, creating an acoustical energy pulse that
is directed downward toward the seabed. WesternGeco will use two source
vessels for the open-water 2001 seismic surveys, one for deep water and
one for shallow water, primarily shoreward of the barrier islands. The
deep water vessel, the R/V Arctic Star, will utilize an airgun array
with an air discharge volume of 1,210 cubic inches (in\3\) (19.8
liters, L). The maximum source levels for the Arctic Star will be at
249 dB re 1 micro Pascal at 1 meter (Pa-m) when the acoustic pressure
is 29.4 bar-meters (zero to peak), which is equivalent to 253 dB re 1
micro Pa-m when the acoustic pressure is 45.9 bar-meters (peak-to-
peak). Most operations utilizing the 1,210 in\3\ array are expected to
operate at a gun depth of 2.3 m (7.5 ft) and water depth of 10 m (32.8
ft). The shallow water source vessel, the R/V Peregrine, will utilize
an airgun array with an air discharge volume of 640 in\3\ (10.48 L).
The source level maximums for the Peregrine will be at 237 dB re 1
micro Pa-m when the acoustic pressure is 6.7 bar-meters (zero to peak),
which is equivalent to 242 dB re 1 micro Pa-m when the acoustic
pressure is 12.2 bar-meters (peak to peak). These airgun arrays are
smaller and less powerful than the arrays used in some other seismic
programs in the Beaufort Sea prior to 1999 and are expected to operate
at a gun depth of 1 m (3.3 ft) in very shallow water.
It is anticipated that the seismic vessels will sail along pre-
plotted source lines arranged orthogonally to the OBCs. Each source
line will be 5 km (3.1 mi) long and adjacent source lines will be
approximately 500 m (1,640 ft) apart. There will be 34 source lines for
each seismic patch. The overall grid of source lines for a given patch
will be 4.7 km by 16.5 km (2.9 mi by 10.2 mi) and the source line for
one patch will overlap with those from adjacent patches.
After sufficient data have been recorded to allow accurate mapping
of the rock strata, the cables are lifted onto the deck of one of the
two self-powered cable vessels (R/V Western Endeavor and R/V Western
Frontier), moved to a new location (ranging from several hundred to a
few thousand feet away), and placed onto the seabed again. A small
utility vessel (Ski Barge) may also be used to transfer seismic crew
and/or marine mammal observers, as well as supplies and refuse, between
the seismic vessels and Prudhoe Bay. Air support will be limited to
infrequent (if any) helicopter flights and, starting after August 31,
2001, aerial surveys at altitudes from 900 to 1500 ft (274 to 457 m).
For a more detailed description of the seismic operation, please refer
to WesternGeco (2001).
Comments and Responses
On June 14, 2001 (66 FR 32321), NMFS published a notice of receipt
and a 30-day public comment period was provided on the application and
proposed authorization. Comments were received from the Marine Mammal
Commission (MMC) and LGL Ltd., environmental research associates
(monitoring contractor for the seismic surveys) on behalf of Western
Geco LLC.
Activity Concerns
Comment 1: The June 14, 2001, Federal Register notice implies that
the 1210 in3 airgun array might be operated at two different pressures:
``249 dB re 1 micro Pa-m equals 29.4 bar-m zero-to-peak, or 253 dB re 1
micro Pa-m equals 45.9 bar-m peak-to-peak.'' LGL Ltd. commented that
these four measurements are all equivalent to one another, and all
would apply simultaneously. The same applies for the pressures quoted
for the 640 in3 airgun array. In addition, LGL Ltd. noted that the ``-
m'' in the unit ``dB re 1 micro Pa-m'' should be read as ``at 1
meter'', not ``per minute'' as stated in the notice.
Response: Thank you for providing this information. NMFS did not
intend to imply that the airgun array(s) would operate at two different
pressures. To clarify, NMFS has added equivalent language to the
sentences referred to within this document. Also, NMFS has corrected
the micro Pascal ``per minute'' reference to read micro Pascal ``at 1
meter''.
Comment 2: LGL Ltd. noted that the statement: ``the highest
frequency in the airgun sounds will be 188 Hz'' is in error. Western's
application states that the dominant frequency components will extend
up to 188 Hz. The energy content decreases with increasing frequency,
but there is some energy at frequencies above 188 Hz. The overall
source level of the 1210 in\3\ array, as quoted in Western's
application, included energy up to 375 Hz.
[[Page 42517]]
Response: NMFS has made the appropriate changes in this document
and has taken this information into account when making its
determinations under the MMPA.
Subsistence Concerns
Comment 3: LGL Ltd. noted that a Conflict Avoidance Agreement for
2001 has been signed by WesternGeco, AEWC, and representatives of the
Kaktovik and Nuiqsuit whaling captains.
Response: Thank you for this information.
Mitigation, Monitoring and Reporting Concerns
Comment 4: LGL Ltd. notes that at the peer/stakeholder workshop in
Seattle on June 5-6, 2001, it was agreed that the number of marine
mammal observers for the 2001 work aboard the Arctic Starwould be three
(two biologists and one Inupiat), not four as the June 14, 2001,
Federal Register notice stated. As in previous years, one marine mammal
observer would be on watch at most times, though 30 minutes prior to
and during airgun startups, and occasionally at other times, two marine
mammal observers would be on watch.
Response: Thank you for this information. NMFS has made the
appropriate changes in this document and has taken this information
into account when making its determinations under the MMPA.
Comment 5: LGL Ltd. notes that at the peer/stakeholder workshop in
Seattle on June 5-6, 2001, it was agreed that the number of marine
mammal observers for the 2001 work aboard the Peregrine would be two
(one biologist and one Inupiat, with no additional observers required
as the June 14, 2001, Federal Register notice stated), provided that
wheelhouse personnel watch for marine mammals at times when no marine
mammal observer is on duty, and that shut down of airguns would be
conducted in the same manner when a marine mammal is seen inside the
safety radius and a marine mammal observer is not on duty. It was also
agreed that when a shutdown is initiated by wheelhouse personnel in the
absence of a marine mammal observer, the shutdown would be recorded but
additional details concerning the marine mammal sighting probably would
not be recorded. It was noted at the peer/stakeholder workshop that the
Peregrine has space for only two marine mammal observers, that frequent
boat-to-boat transfers of personnel are undesirable from a safety
perspective, and that the Peregrine will operate in shallow waters
(mainly a lagoon) where bowhead whales are highly unlikely to occur and
where seal densities may be relatively low.
Response: Thank you for this information. NMFS concurs with this
change in the monitoring requirements aboard the Peregrine, with one
exception. When a shut down occurs and a marine mammal observer is not
on duty, the wheelhouse personnel must notify one of the marine mammal
observers so that they can record the information required by NMFS.
This was agreed upon by NMFS and WesternGeco at the peer/stakeholder
meeting on June 6, 2001 as part of WesternGeco's standard operating
procedures. NMFS has made the appropriate changes in this document and
has taken this information into account when making its determinations
under the MMPA.
Comment 6: The MMC concurs with NMFS that the proposed activities
in the Alaskan Beaufort Sea will result, at most, in a temporary
modification of the behavior of certain species of cetaceans and
pinnipeds. The MMC also concurs that the monitoring and mitigation
measures proposed by WesternGeco appear to be adequate to ensure that
the planned surveys will not result in the mortality or serious injury
of any marine mammals or have unmitigable adverse effects on the
availability of marine mammals for taking by Alaska Natives for
subsistence uses. Therefore, the MMC recommends that the requested IHA
be issued, provided that NMFS is satisfied that the monitoring and
mitigation programs will be carried out as described in the
application.
Response: Thank you for the comment. On June 5, 2001, NMFS convened
a peer-review/stakeholders meeting in Seattle, WA to discuss the
proposed monitoring and mitigation measures for this seismic survey
program. A description of the monitoring and mitigation that will be
required for this activity is described later in this document.
Although NMFS has no reason to believe that the monitoring and
mitigation programs will not be carried out, a report on all activities
under the IHA will be required to be submitted to NMFS within 90 days
of completion of the planned survey. This report will be reviewed by
NMFS to determine whether WesternGeco fully complied with the terms and
conditions of the IHA, including the monitoring and mitigation
requirements.
Comment 7: The MMC questions whether there is a sufficient basis
for concluding that this activity, combined with past and possible
future activities in this region, is unlikely to have non-negligible
cumulative effects on any of the potentially affected marine mammal
species or their availability to Alaska Natives for subsistence uses.
Therefore, the MMC recommends (as in previous letters) that NMFS, in
consultation with the applicant, the Alaska Department of Fish and
Game, and the Native communities, determine the long-term monitoring
that would be required to confirm that the proposed seismic surveys and
possible future exploration and development activities do not cause
changes in the seasonal distribution patterns, abundance, or
productivity of marine mammal populations in the area. MMC recommends
that such consultations address: (1) the possibility that the sum of
exploration and development activities could have significant
cumulative adverse effects on marine mammal behavior and distribution;
(2) whether previous and proposed monitoring programs have provided and
will continue to provide adequate baseline data for detecting possible
future changes in the distribution, abundance, or productivity of the
potentially affected marine mammal populations; (3) changes in the
planned marine mammal and acoustic monitoring program that would be
required to provide adequate baseline data; and, (4) whether the
purposes of the MMPA and the Endangered Species Act might be met more
cost-effectively by designing and implementing long-term monitoring
programs to replace or augment the site-specific monitoring currently
required.
Response: Thank you for the recommendation. Based on the best
available scientific information, WesternGeco's proposed OBC seismic
survey is unlikely to have more than minimal behavioral effects on
marine mammal species in the area. If the survey period extends into
the fall bowhead migration season, there may be some effect on bowhead
whales migrating inshore. However, some of WesternGeco's seismic work
will be conducted shoreward of the barrier islands, where noise from
the survey would be unlikely to reach the main migration path for
bowheads. In addition, the seismic arrays being used will never be
fired simultaneously.
NMFS recognizes the need to address potential adverse cumulative
impacts from oil and gas exploratory and development activities on both
marine mammal stocks and subsistence needs. The 2001 scientific peer
review workshop participants concluded that the current research and
monitoring proposed by WesternGeco for seismic surveys, by BPX for oil
development at Northstar, and by BP/EM/PAI for
[[Page 42518]]
shallow hazard surveys (see 66 FR 32321, June 14, 2001, 65 FR 34014,
May 25, 2000, and 66 FR 29287, May 30, 2001), coupled with existing
projects to monitor bowhead population abundance (trends in abundance)
should provide the information necessary to provide baseline data and
determine overall cumulative impacts from noise on bowhead whales.
Existing long-term monitoring projects that augment current site-
specific monitoring required under MMPA authorizations, include: (1)
the North Slope Borough spring bowhead census; (2) the Minerals
Management Service's (MMS) autumn aerial survey; and, (3) an MMS-funded
bowhead whale photo-identification project conducted in conjunction
with bowhead whale feeding studies. Similar work is underway for ringed
seals. Provided trends in bowhead (and other species') abundance
continue to be positive and until new scientific information is made
available, NMFS presumes industrial development on the North Slope is
not adversely affecting the bowhead population.
Description of Habitat and Marine Mammals Affected by the Activity
A detailed description of the Beaufort Sea ecosystem and its
associated marine mammals can be found in several documents (Corps of
Engineers, 1999; NMFS, 1999; Minerals Management Service (MMS), 1992,
1996) and does not need to be repeated here.
Marine Mammals
The Beaufort/Chukchi Seas support a diverse assemblage of marine
mammals, including bowhead whales (Balaena mysticetus), gray whales
(Eschrichtius robustus), beluga whales(Delphinapterus leucas), ringed
seals (Phoca hispida), spotted seals (Pusa largha) and bearded seals
(Erignathus barbatus). Descriptions of the biology and distribution of
these species and of others can be found in NMFS (1999), Western
Geophysical (2000), WesternGeco (2001), the annual monitoring reports
for seismic surveys in the Beaufort Sea (LGL Ltd. and Greeneridge
Sciences Inc, 1997, 1998, 1999, 2000) and several other documents
(Corps of Engineers, 1999; Lentfer, 1988; MMS, 1992, 1996; Ferrero et
al., 2000). Please refer to those documents for information on these
species.
Potential Effects of Seismic Surveys on Marine Mammals
Disturbance by seismic noise is the principal means of taking by
this activity. Support vessels and aircraft may provide a potential
secondary source of noise. The physical presence of vessels and
aircraft could also lead to non-acoustic effects on marine mammals
involving visual or other cues.
Underwater pulsed sounds generated by open water seismic operations
may be detectable a substantial distance away from the activity. The
effect of these pulsed sounds on living marine resources, particularly
marine mammals in the area, will be dependent on the hearing
sensitivity of the species, the behavior of the animal at the time the
sound is detected, as well as the distance and level of the sound
relative to ambient conditions. Any sound that is detectable is (at
least in theory) capable of eliciting a disturbance or avoidance
reaction by some marine mammals or of masking signals of comparable
frequency that are generated by marine mammals (e.g., whale calls)
(WesternGeco, 2001). An incidental harassment take is presumed to occur
when marine mammals in the vicinity of the seismic source, the seismic
vessel, other vessels, or aircraft show a disturbance or avoidance
reaction to the generated sounds or to visual cues.
When the received levels of noise exceed some behavioral reaction
threshold, cetaceans will show disturbance reactions. The levels,
frequencies, and types of noise that will elicit a response vary
between and within species, individuals, locations, and seasons.
Behavioral changes may be subtle alterations in the surface,
respiration, and dive cycles. More conspicuous responses include
changes in activity or aerial displays, movement away from the sound
source, or complete avoidance of the area. The reaction threshold and
degree of response are related to the activity of the animal at the
time of the disturbance. Whales engaged in active behaviors, such as
feeding, socializing, or mating, are less likely than resting animals
to show overt behavioral reactions, unless the disturbance is directly
threatening. Seismic pulses have been observed to cause strong
avoidance reactions by many of the bowhead whales occurring within a
distance of several kilometers, including changes in surfacing,
respiration and dive cycles, and to sometimes cause avoidance or other
changes in bowhead behavior at considerably greater distances
(Richardson et al., 1995; Rexford, 1996; MMS, 1997; Miller et al.,
1999). Airgun pulses may also disturb some other marine mammal species
occurring in the area. Ringed seals within a few hundred meters of an
airgun array showed variable reaction to the noise, with some moving
somewhat farther away and other seals not moving far at all (Harris et
al., 1997, 1998, in press; Lawson and Moulton, 1999; Moulton and
Lawson, 2000). It is likely that avoidance distances around nearshore
seismic operations of the type planned for 2001 may be less than those
around some of the seismic operations that were done in the Beaufort
Sea before 1996 for the following reasons: (1) The recent seismic
operations have been in shallow water, (2) the recent seismic
operations have been limited to a confined area at any one time, and
(3) the recent seismic operations have employed smaller airgun arrays
than those that were used in the past.
Although some limited masking of low-frequency sounds (e.g.,
bowhead and gray whale calls) is a possibility, the intermittent nature
of seismic survey pulses used by WesternGeco (1 second in duration
every 16 to 24 seconds), as well as the fact that airgun operations are
expected to occur no more than 50 percent of the time, will limit the
extent of masking. Bowhead whales are known to continue calling in the
presence of seismic survey sounds, and their calls can be heard between
seismic pulses (Greene et al., 1997, 1999; Richardson et al., 1986).
Masking effects are expected to be absent in the case of beluga whales,
given that sounds utilized by them are at much higher frequencies (in
the 2 to 6 kilohertz (kHz) range) (Sjare and Smith, 1986) than airgun
sounds from WesternGeco's seismic surveys (dominant frequency
components will extend up to 188 hertz(Hz)) (WesternGeco, 2001).
Permanent hearing damage is not expected to occur during the
project. There is no direct evidence that the hearing systems of marine
mammals close to an airgun array would be at risk of temporary or
permanent hearing impairment; however, depending on the species, the
equipment being used, and the number of pulses to which the animal is
exposed, temporary threshold shift (TTS) is a theoretical possibility
for animals within a few hundred meters of the source (Richardson et
al., 1995; Finneran et al., 2000).
Planned monitoring and mitigation measures, proposed by WesternGeco
and described later in this document, are designed to avoid sudden
onsets of seismic pulses at full power, to detect marine mammals
occurring near the array, and to avoid exposing them to sound pulses
that have any possibility of causing hearing impairment.
For a discussion on the anticipated effects of ships, boats, and
aircraft on marine mammals and their food sources, and for a more
complete review of the best available information
[[Page 42519]]
available on the potential effects of seismic surveys to marine mammals
in the Arctic, please refer to the application (WesternGeco, 2001) and
the Federal Register notice of June 14, 2001 (66 FR 32321).
Numbers of Marine Mammals Expected to Be Taken
Based on an analysis provided in their application, WesternGeco
estimates that the following numbers of marine mammals may be subject
to Level B harassment, as defined in 50 CFR 216.3:
------------------------------------------------------------------------
Harassment Takes in 2001
Species Population Size ---------------------------------
Possible Probable
------------------------------------------------------------------------
Bowhead 8,200 ............... ...............
160 dB criterion ................. 1,000 500
2 0km criterion ................. 2,630 1,300
Gray whale 26,000 10 0
Beluga whale 39,258 250 150
Ringed seal\3\ 1-1.5 million 400 200
Spotted seal\3\ >200,000 10 2
Bearded seal\3\ >300,000 50 15
------------------------------------------------------------------------
1 The maximum number that might be taken if seismic surveys are operable
during the September/October period and the bowhead migration passes
unusually close to shore as in 1997.
2 The number that could be taken under the most likely operating
conditions.
3 Some individual seals may be harassed more than once
At the 2001 open water peer-review workshop held in Seattle on June
5\th\ and 6\th\, the attendees agreed on support of the following
statement based on methods and results reported in Miller et al.
(1999): ``Monitoring studies of 3-D seismic exploration (6-18 airguns
totaling 560-1500 in\3\) in the nearshore Beaufort Sea during 1996-1998
have demonstrated that nearly all bowhead whales will avoid an area
within 20 km of an active seismic source, while deflection may begin at
distances up to 35 km. Sound levels received by bowhead whales at 20 km
ranged from 117-135 dB re 1 micro Pa rms and 107-126 dB re 1 micro Pa
rms at 30 km. The received sound levels at 20-30 km are considerably
lower levels than have previously been shown to elicit avoidance in
bowhead or other baleen whales exposed to seismic pulses.'' NMFS adopts
the Miller et al. research and the peer review workshop's statement as
the best scientific information available on bowhead whale reactions to
seismic sources. Given this information, NMFS utilized the 20 km
criterion estimates of take for bowhead whales provided by WesternGeco
in determining the number of harassment takes to be authorized under
the IHA for the 2001 open water season.
Estimates of Marine Mammal Takes
Estimates of takes by harassment will be made through vessel and/or
aerial surveys. Preliminarily, WesternGeco will estimate the number of
(1) marine mammals observed within the area ensonified strongly by the
OBC seismic vessel (see Mitigation section of this document for
description of safety radii); (2) marine mammals observed showing
apparent avoidance or disturbance reactions to seismic pulses (e.g.,
heading away from the seismic vessel in an atypical direction); (3)
marine mammals estimated to be subject to take by type (1) or (2) when
no monitoring observations were possible; and (4) bowhead whales whose
migration routes come within 20 km (actual distance dependent on a
combination of 1996-1998 and 2001 data) of the operating OBC seismic
vessel, or would have if they had not been displaced farther offshore.
Effects of Seismic Noise and Other Activities on Subsistence Needs
The disturbance and potential displacement of marine mammals by
sounds from seismic activities are the principle concerns related to
subsistence use of the area. The harvest of marine mammals (mainly
bowhead whales, but also ringed and bearded seals) is central to the
culture and subsistence economies of the coastal North Slope
communities. In particular, if migrating bowhead whales are displaced
farther offshore by elevated noise levels, the harvest of these whales
could be more difficult and dangerous for hunters. The harvest could
also be affected if bowhead whales become more ``skittish'' when
exposed to seismic noise.
The location of the proposed seismic activity is south of the
center of the westward migration route of bowhead whales, but there is
some limited overlap with the southern limit of the migration. Seismic
monitoring results from 1996-1998 indicate that most bowhead whales
avoid the area within about 20 km (12.4 mi) around the airgun array
when it is operating, and some avoid the area within 30 km (18.6 mi).
In addition, bowhead whales may be able to hear the sounds emitted by
the seismic array out to a distance of 50 km (31.1 mi) or more,
depending on the ambient noise level and the efficiency of sound
propagation along the path between the seismic vessel and the whale
(Miller et al., 1997).
Nuiqsut is the community closest to the area of the proposed
activity. The communities of Barrow and Kaktovik also harvest resources
that pass through the general area, but do not regularly hunt in the
planned seismic exploration area. Subsistence hunters from all three
communities conduct an annual hunt for migrating bowhead whales during
the autumn months. In recent years, Nuiqsut whalers have typically
taken two to four whales each year (WesternGeco, 2001). Nuiqsut whalers
concentrate their efforts on areas north and east of Cross Island,
generally in water depths greater than 20 m (65 ft). Cross Island, the
principle field camp location for Nuiqsut whalers, is located within
the general area of the proposed 2001 seismic area.
Whalers from the village of Kaktovik search for whales east, north,
and west of the village. Kaktovik is located 72 km (45 mi) east of the
easternmost end of WesternGeco's planned 2001 seismic exploration area.
Whalers from the village of Barrow search for bowhead whales >200
km (>125 mi) to the west of the planned seismic area (WesternGeco,
2001).
Nuiqsut hunters also hunt seals for subsistence purposes. Most seal
hunting has been during the early summer in open water. Boat crews hunt
ringed, spotted, and bearded seals. The most important sealing area for
Nuiqsut
[[Page 42520]]
hunters is off the Colville Delta, extending as far west as Fish Creek
and as far east as Pingok Island. The planned seismic exploration
during the summer has some potential to influence seal hunting
activities by residents of Nuiqsut. During BP and Western Geophysical's
1996-2000 seismic programs, an operating airgun array apparently did
not displace seals by more than a few hundred meters.
The possibility and timing of potential seismic operations in the
Cross Island area and in Nuiqsut sealing areas required WesternGeco to
provide NMFS with either (1) a Plan of Cooperation with the Alaska
Eskimo Whaling Commission (AEWC) and the North Slope whaling
communities, or (2) measures that have been or will be taken to avoid
any unmitigable adverse impact on the availability of these animals for
subsistence needs. The timing of seismic operations has been addressed
in a Conflict Avoidance Agreement (CAA) between WesternGeco, the
Nuiqsut and Kaktovik whalers, and the AEWC (WesternGeco, 2001). In
addition, WesternGeco's application identifies, and the IHA has
incorporated, mitigation and monitoring measures that will be taken to
minimize any adverse effect on subsistence uses and improve the state
of knowledge on the effects of seismic exploration on the accessibility
of bowhead whales to hunters.
Anticipated Impact on Habitat
The proposed seismic activity is not expected to cause significant
and permanent impacts on habitats used by marine mammals, or to the
food sources they utilize. The main impact issue associated with the
proposed activity will be temporarily elevated noise levels. For a more
detailed analysis of anticipated impact on habitat refer to the
application (WesternGeco, 2001) and the Federal Register notice of June
14, 2001 (66 FR 32321).
The 2001 OBC survey area may overlap with areas identified as
``Boulder Patch'' habitat. WesternGeco is required by the State of
Alaska to consult with NMFS as to the location and resources of the
Stephansson Sound Boulder Patches so that they may be avoided.
Mitigation
For the 2001 seismic operations, WesternGeco will reduce its
primary airgun array from the 1,500 in3 used in 1998 to 1,210 in\3\.
This reduction in volume will lower the source levels and result in
lower received levels at each distance compared to Western
Geophysical's 1998 project. The smaller volume 640 in3 airgun array
consists of sixteen 40 in\3\ airguns in four 4-gun clusters. The
airguns comprising this small volume array will be spread out
horizontally, such that the energy from the array, like that from the
1,210 in\3\ array, will be directed downward insofar as possible. The
distances within which received levels (see the proposed safety radii
below) can exceed 190 dB and 180 dB re 1 micro-Pa have been measured at
two airgun depths (2.3 and 5 m or 7.5 and 16.4 ft) and in two water
depths (8 and 23 m or 26.2 and 75.5 ft) (Greene and McLennan, 2000),
and are reduced relative to those around the 1998 array. The shallower
depth at which the 640 in\3\ array will operate will tend to reduce the
source level (and hence the 190 and 180 dB safety radii) even farther;
however, as a precautionary approach, the 190 and 180 dB radii for the
1,210 in\3\ airgun operating at 2.3 m (7.5 ft) depth will be assumed to
apply to the 640 in\3\ array operating at 1 m (3.3 ft) gun depth.
The safety radii for OBC seismic operations in 2001 are based on
comprehensive measurements of the sounds recorded in the water near the
OBC array in 1999 and analyzed by Greene and McLennan (2000).
Vessel-based observers will monitor marine mammal presence in the
vicinity of the seismic arrays throughout the seismic program. To avoid
the potential for injury, WesternGeco will immediately shut down the
seismic source if seals and/or whales are sighted within the safety
radii. The safety radii are as follows:
----------------------------------------------------------------------------------------------------------------
SAFETY RADII(m/ft)
AIRGUN DEPTH WATER DEPTH (m/-------------------------
SOURCE (in\3\) (m/ft) ft) 190 dB 180 dB
(Seals) (Whales)
----------------------------------------------------------------------------------------------------------------
1210 2.3/7.5 10/32.8 100/328 150/492
1210 2.3/7.5 >10/>32.8 160/525 550/1,804
1210 5/16.4 10/32.8 160/525 350/1,148
1210 5/16.4 >10/>32.8 260/853 900/2,953
640 1/3.3 10/32.8 100/328 150/492
640 1/3.3 >10/>32.8 160/525 550/1,804
----------------------------------------------------------------------------------------------------------------
In addition, WesternGeco will ramp-up the 1,210 in\3\ and 640 in\3\
seismic sources to operating levels at a rate no greater than 6 dB per
minute. Under normal operational conditions (source vessel speed at
least 4 knots), a ramp-up will be required after the array has been
inactive for a period lasting 1 minute or longer. If the towing speed
is reduced to 3 knots or less, a ramp-up will be required after the
array has been inactive for a period lasting 2 minutes or longer. Ramp-
up will begin with an air volume discharge not exceeding 80 in\3\ for
the 1,210 in\3\, and 40 in\3\ for the 640 in\3\ array. Additional guns
will be added at appropriate intervals so as to limit the rate of
increase in source level to 6 dB per minute.
Monitoring
As part of its application, WesternGeco provided a monitoring plan
for assessing impacts to marine mammals from seismic surveys in the
Beaufort Sea. This monitoring plan is described in WesternGeco (2001)
and in LGL, Ltd. and Greeneridge Sciences Inc. (2001).
The monitoring plan submitted to NMFS on April 16, 2001, was
reviewed at a peer-review workshop held in Seattle, WA, on June 5-6,
2001. The monitoring plan, with minor modifications, was accepted by
NMFS at this meeting. A copy of the monitoring plan is available upon
request (see ADDRESSES).
WesternGeco plans to conduct the following monitoring:
Vessel-based Visual Monitoring
One or two marine mammal observers aboard the seismic source
vessels will search for and observe marine mammals whenever seismic
operations are in progress and for at least 30 minutes before the
planned start of seismic transmissions. These observers will scan the
area immediately around the vessels with reticle binoculars during the
daytime. Laser rangefinding binoculars will be available to assist with
distance estimation. If operations continue after mid-August, when the
duration of
[[Page 42521]]
darkness increases, image intensifiers and additional light sources
will be used to illuminate the safety zone (see application for more
detail).
A total of three observers (two trained biologists and one Inupiat
observer/communicator) will be based aboard the seismic source vessel
Arctic Star. Two observers must be on active watch 30 minutes prior to
and during the start of seismic transmissions and a minimum of one
observer needs to be on active watch aboard the Arctic Star whenever
the seismic sources are operating during daylight hours.
A total of two observers will be based aboard the seismic source
vessel Peregrine. A minimum of one observer must be on active watch 30
minutes prior to and during the start of seismic transmissions and a
minimum of one observer must be on active watch aboard the Peregrine
for a total of 16 hours during any given 24 hour period when seismic
operations are taking place. In addition, wheelhouse staff aboard the
Peregrine will assist in maintaining a watch for marine mammals. During
the hours when a marine mammal observer is not on duty, wheelhouse
personnel must actively watch for marine mammals, follow all shut-down
procedures if a marine mammal is sighted within the designated safety
zones, and notify the marine mammal observer(s) any time a shut-down
occurs.
Vessel-based monitoring will include recording information on
seismic operations, vessel activities, marine mammals sighted, and
other relevant activity in a standardized format.
Aerial Surveys
If OBC seismic work continues after August 31, 2001, aerial surveys
by WesternGeco's marine mammal contractor, LGL Ltd., will occur from
the date on which OBC seismic operations commence until 1 day after the
OBC seismic operations end. If OBC seismic work is suspended during the
bowhead subsistence hunting season, but resumes later in the autumn,
aerial surveys will commence (or resume) when OBC seismic work resumes.
WesternGeco will continue aerial surveys until 1 day after OBC seismic
work ends. It should be noted that the proposed duration for aerial
surveys would be a reduction from previous years. WesternGeco believes
this reduction is appropriate because some of the main questions about
disturbance to bowhead whales from a nearshore seismic operation have
been answered through the 1996-1998 monitoring projects. In addition,
the MMS expects to conduct its broad-scale aerial survey work from
approximately August 31 until the end of the bowhead migration in
October. WesternGeco believes that this combined aerial survey data
will provide sufficient information to estimate the numbers of bowhead
whales taken by harassment.
The primary objective of WesternGeco's aerial surveys will be to
document the occurrence, distribution, and movements of bowhead whales,
and (secondarily) beluga and gray whales in and near the area where
they might be affected by the seismic pulses. These observations will
be used to estimate the level of harassment takes and to assess the
possibility that seismic operations affect the accessibility of bowhead
whales for subsistence hunting. Pinnipeds will be recorded when seen,
although survey altitude will be too high for systematic surveys of
these species. Sonobuoys will be dropped to document seismic and
ambient noise at offshore locations, including locations near whales.
WesternGeco will fly at 300 m (1,000 ft) in areas where no whaling
is underway, with a minimum altitude of no less than 275 m (900 ft)
under low cloud conditions. In addition, and subject to the terms of
the 2001 CAA with subsistence communities, surveys will be flown at 457
m (1500 ft) altitude over areas where whaling is occurring and will
avoid direct overflights of whaleboats and Cross Island.
The daily aerial surveys are designed to cover a grid of 18 north-
south lines spaced 8 km (5 mi) apart and extending seaward to about the
100 m (328 ft) depth contour (typically about 65 km (40.4 mi)
offshore). This grid will extend from about 65 km (40.3 mi) east to 65
km (40.3 mi) west of the area in which seismic operations are underway
on that date. This survey design will provide extended coverage to
determine the eastward and westward extent of the offshore displacement
of whales by seismic operations. Because of the inshore nature of the
2001 seismic surveys, few whales are expected to occur within 20 km
(12.4 mi) of the operations; therefore, no ``intensive'' grid surveys
are planned.
Detailed information on the aerial survey program can be found in
WesternGeco (2001) and in LGL Ltd. and Greeneridge Sciences Inc.
(2001), which are incorporated in this document by citation.
Acoustical Measurements
The acoustic measurement program for 2001 is designed to provide,
in conjunction with existing results from previous years (see LGL and
Greeneridge Sciences Inc., 1997, 1998, 1999), the specific acoustic
data needed to document the seismic sounds to which marine mammals will
be exposed in 2001. This measurement program will only be operable if
seismic operations continue after August 31, 2001. Proposed emphasis is
on situations and locations not studied in detail during previous
operations.
WesternGeco has two basic objectives for collecting acoustic
measurements, one physical and one biological. The physical acoustics
objective is to determine the characteristics of airgun array pulses as
received in the bowhead migration corridor at varying distances
offshore and to the east of the area of seismic exploration in 2001 and
in 1996- 98 plus 2001 combined. Pulse characteristics to be determined
are received levels and pulse durations versus range offshore and to
the east, spectral properties, and signal-to-ambient ratios. The
biological objective is to determine whether there are differences in
the pattern of bowhead call detection rates near, offshore of, and east
of the seismic exploration area at times with and without active
seismic operations based on 2001 data and combined 1996-98 and 2001
data. If there are differences, then WesternGeco will use the combined
acoustic and aerial survey data to evaluate whether the noise-related
differences in call detection rate are attributable to differences in
calling behavior, whale distribution, or a combination of the two.
In 2001, the acoustic measurement program is planned to include (1)
deployment in late August/September of autonomous seafloor acoustic
recorders (ASARs) to provide continuous acoustic data for extended
periods, and (2) use of air-dropped sonobuoys in September/October.
WesternGeco will use these methods only if OBC surveys occur in
September/October.
For a more detailed description of planned monitoring activities,
please refer to the application and the Technical Monitoring Plan
(WesternGeco, 2001; LGL Ltd. and Greeneridge Sciences Inc., 2001) and
the Federal Register notice of June 14, 2001 (66 FR 32321).
Reporting
WesternGeco will provide an initial report on 2001 activities to
NMFS within 90 days after the end of the seismic program. This report
will summarize dates and locations of seismic operations, marine mammal
sightings (dates, times, locations, behaviors, associated seismic
survey activities), estimates of the amount and nature of all takes by
harassment or in other ways, and any apparent effects on
[[Page 42522]]
accessibility of marine mammals to subsistence users.
A final technical report will be provided by WesternGeco within 20
working days of receipt of the document from the contractor, but no
later than April 30, 2002. The final technical report will contain a
description of the methods, results, and interpretation of all
monitoring tasks.
Consultation
Under section 7 of the Endangered Species Act (ESA), NMFS completed
consultation with MMS on oil and gas exploration and associated
activities in the Alaskan Beaufort Sea on May 25, 2001. This
consultation includes a review of seismic and related noise sources
used by the oil and gas industry. The finding of that consultation was
that oil and gas activities in the Alaskan Beaufort Sea, and the
issuance by NMFS of a small take authorization for oil and gas
activities, are not likely to jeopardize the continued existence of the
bowhead whale. In formulating this opinion, NMFS used the best
available information, including information provided by MMS, recent
research on the effects of oil and gas activities on the bowhead whale,
and the traditional knowledge of Native hunters and the Inupiat along
Alaska's North Slope. A copy of the Biological Opinion issued as a
result of this consultation is available upon request (see ADDRESSES).
National Environmental Policy Act (NEPA)
In conjunction with the 1996 notice of proposed authorization (61
FR 26501, May 28, 1996) for open water seismic operations in the
Beaufort Sea, NMFS released an Environmental Assessment (EA) that
addressed the impacts on the human environment from issuance of the
authorization and the alternatives to the proposed action. No comments
were received on that document and, on July 18, 1996, NMFS concluded
that neither implementation of the proposed authorization for the
harassment of small numbers of several species of marine mammals
incidental to conducting seismic surveys during the open water season
in the U.S. Beaufort Sea nor the alternatives to that action would
significantly affect the quality of the human environment. As a result,
the preparation of an environmental impact statement on this action is
not required by section 102 (2) of NEPA or its implementing
regulations.
In 1999, NMFS determined that a new EA was warranted. This
determination was based on (1) the proposed construction of the
Northstar project by BP, Alaska, (2) the collection of data from 1996
through 1998 on Beaufort Sea marine mammals and the impacts of seismic
activities on these mammals, and (3) the analysis of scientific data
indicating that bowhead whales avoid nearshore seismic operations by a
distance of approximately 20 km (12.4 mi). Accordingly, a review of the
impacts expected from the issuance of an IHA have been assessed in the
EA, in the Federal Register notice of June 14, 2001 (66 FR 32321), and
in this document. NMFS has determined that there will be no more than a
negligible impact on marine mammals from the issuance of the IHA and
that there will not be any unmitigable impacts to subsistence
communities, provided the mitigation measures required under the
authorization are implemented. As a result, NMFS determined, as in
1999, that neither implementation of the authorization for the
harassment of small numbers of several species of marine mammals
incidental to conducting seismic surveys during the open water season
in the U.S. Beaufort Sea nor the alternatives to that action would
significantly affect the quality of the human environment. Since this
proposed action falls into a category of actions that do not
individually or cumulatively have a significant impact on the human
environment, as determined through the 1999 EA, this action is
categorically excluded from further NEPA analysis (NOAA NAO 216-6). A
copy of the 1999 EA is available upon request (see ADDRESSES).
Coastal Zone Management Act Consistency
The State of Alaska, Department of Natural Resources, Division of
Oil and Gas issued a proposed Alaska Coastal Management Program
consistency determination on June 21, 2001, for WesternGeco's planned
3-D seismic surveys on state tide and submerged lands in the Beaufort
Sea during the open water season of 2001. Based on the State's review,
performed under 6 AAC 50, the State concurred that the project is
consistent with the ACMP as long as: (1) Operations beyond September 1
will be considered on a case-by-case basis if the Director, Division of
Oil and Gas, in consultation with NMFS, determines that: (a) a suitable
whale monitoring program will be conducted and appropriate measures to
minimize conflict with the Nuiqsuit subsistence whale harvests will be
taken; or (b) the Village of Nuiqsuit has completed its whale hunt for
2001; or (c) NMFS has issued an IHA; (2) all operations must be
conducted in a manner that will assure minimum conflict with other
users of the area, including coordination with local whaling crews as
needed to avoid conflicts with the subsistence whale hunt; (3) seismic
activities shall avoid or minimize interference with traditional food
gathering and access to subsistence resources; and (4) permittee will
consult with NMFS' Alaskan Offices as to the location and resources of
the Stephansson Sound Boulder Patches and any operational changes made
in response to this consultation will be disclosed in the completion
report.
Determinations
Based on the evidence provided in the application, the EA, the
Federal Register notice (66 FR 32321), and this document, and taking
into consideration the comments submitted on the application and
proposed authorization notice, NMFS has determined that there will be
no more than a negligible impact on marine mammals from the issuance of
the harassment authorization to WesternGeco, LLC and that there will
not be any unmitigable adverse impacts to subsistence communities. NMFS
has determined that the short-term impact of conducting OBC seismic
operations in the Alaskan Beaufort Sea will result, at worst, in a
temporary modification in behavior by certain species of pinnipeds and
cetaceans. Behavioral modifications may be made by these species to
avoid noise from seismic operations; however, this behavioral change is
expected to have a negligible impact on marine mammal species and
stocks mentioned here. Due to the distribution and abundance of marine
mammals during the projected period of activity and the location of the
seismic operations in waters generally too shallow and distant from the
edge of the pack ice for most marine mammals of concern, the number of
potential harassment takings is estimated to be small.
Since (1) the number of potential harassment takings of bowhead
whales, gray whales, beluga whales, ringed seals, spotted seals, and
bearded seals is estimated to be small; (2) no take by injury and/or
death is anticipated; (3) the potential for temporary or permanent
hearing impairment is low and will be avoided through the incorporation
of the mitigation measures mentioned in this document and required
under the IHA; and (4) no rookeries, mating grounds, year-round areas
of concentrated feeding, or other areas of special significance for
marine mammals occur within or near the planned area of operations
during the season of operations, NMFS has determined that the
requirements of section 101 (a)(5)(D) of the MMPA have
[[Page 42523]]
been met and the authorization can be issued.
Appropriate mitigation measures to avoid an unmitigable adverse
impact on the availability of bowhead whales for subsistence needs have
been the subject of a CAA between WesternGeco, the AEWC, and Nuiqsut
and Kaktovik whalers. This agreement consists of three main components:
(1) Communications, (2) conflict avoidance, and (3) dispute resolution,
and has been concluded for the 2001 open-water seismic season.
WesternGeco estimates that 2,630 bowheads could potentially be
exposed to its OBC seismic survey activities and, more probably, a
total of less than 1,300 bowheads may be harassed based on the number
of bowheads that might potentially be within 20 km of the airgun
arrays. NMFS concurs and is therefore authorizing a take for bowhead
whales by Level B harassment of 1,965 animals (based on the average of
2,630 and 1,300 animals). NMFS believes that no bowheads will be killed
or seriously injured by WesternGeco's activity and accordingly has not
authorized takings for injury or mortality.
Open-water seismic exploration in the Alaskan Beaufort Sea does
have some potential to influence seal hunting activities by residents
of Nuiqsut. However, because the main summer sealing by the village of
Nuiqsut is conducted off the Colville Delta, west of the proposed
survey area, and the zone of influence by seismic sources on seals is
expected to be fairly small (less than a few hundred meters), NMFS
believes that WesternGeco's OBC seismic survey will not have an
unmitigable adverse impact on the availability of seals for subsistence
uses.
Authorization
Accordingly, NMFS has issued an IHA to WesternGeco, LLC for the
ocean bottom cable seismic survey operations described in this notice
during the 2001 open water season in the Alaskan Beaufort Sea provided
the mitigation, monitoring, and reporting requirements described in
this document and in the IHA are undertaken.
Dated: August 1, 2001.
Donald Knowles,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 01-20281 Filed 8-10-01; 8:45 am]
BILLING CODE 3510-22-S