[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