[Federal Register Volume 64, Number 103 (Friday, May 28, 1999)]
[Notices]
[Pages 28992-28997]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13565]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration
[I.D. 040799A]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Offshore Seismic Activities in the Beaufort Sea

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

ACTION: Notice of receipt of application and proposed authorization for 
a small take exemption; request for comments.

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SUMMARY: NMFS has received a request from Western Geophysical/Western 
Atlas International of Houston, Texas (Western Geophysical) for an 
authorization to take small numbers of marine mammals by harassment 
incidental to conducting seismic surveys in the Beaufort Sea in state 
and Federal waters. Under the Marine Mammal Protection Act (MMPA), NMFS 
is requesting comments on its proposal to authorize Western Geophysical 
to incidentally take, by harassment, small numbers of bowhead whales 
and other marine mammals in the above mentioned areas during the open 
water period of 1999.

DATES: Comments and information must be received no later than June 28, 
1999.

ADDRESSES: Comments on the application should be addressed to Donna 
Wieting, Acting Chief, Marine Mammal Division, Office of Protected 
Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 20910-3225. 
A copy of the application, a list of references used in this document, 
and/or an environmental assessment (EA) may be obtained by writing to 
this address or by telephoning one of the contacts listed here.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, (301) 713-
2055, Brad Smith, (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 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 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 that 
document.

Summary of Request

    On March 24, 1999, NMFS received an application from Western 
Geophysical requesting an 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 Beaufort Sea 
between western Camden Bay and Harrison Bay off Alaska. 
Weather permitting, the survey is expected to take place between 
approximately July 1 and mid- to late-October, 1999. However, only a 
small portion of the area between western Camden Bay and 
Harrison Bay will be surveyed this year. A detailed 
description of the work proposed for 1999 is contained in the 
application (Western Geophysical, 1999) and is available upon request 
(see ADDRESSES).

Description of Habitat and Marine Mammal Affected by the Activity

    A detailed description of the Beaufort Sea ecosystem and its 
associated marine mammals can be found in the EA prepared for this 
authorization or in other documents (Corps of Engineers, 1999; Minerals 
Management Service (MMS), 1992, 1996). The relevant information 
contained in these documents is incorporated by citation into this 
section and need not be repeated here. A copy of the EA is available 
upon request (see ADDRESSES).

Marine Mammals

    The Beaufort/Chukchi Seas support a diverse assemblage of marine 
mammals, including bowhead whales (Balaena mysticetus), gray whales 
(Eschrichtius robustus), beluga (Delphinapterus leucas), ringed seals 
(Phoca hispida), spotted seals (Phoca largha) and bearded seals 
(Erignathus barbatus). Descriptions of the biology and distribution of 
these species and of others can be found in the previously referenced 
EA, the 1999 application from Western Geophysical, the annual 
monitoring reports for seismic surveys in the Beaufort Sea (LGL Ltd. 
and Greeneridge Sciences Inc, 1997, 1998, and 1999a) and several other 
documents (Corps of Engineers, 1999; Lentfer, 1988; MMS, 1992, 1996; 
Hill et al., 1997). 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 will 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.
    Seismic surveys are used to obtain data about formations several 
thousands of feet deep. The proposed seismic operation is an ocean 
bottom cable (OBC) survey. For this activity, OBC surveys involve 
dropping cables from a ship to the ocean bottom, forming a

[[Page 28993]]

patch consisting of 4 parallel cables 8.9 kilometers (km) (4.8 nautical 
miles (nm)) 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 
underground rock strata. 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. The source level planned for 
this project - a maximum of 247 dB re 1 Pa-m or 22.3 bar-
meters (zero to peak), or a maximum of 252 dB re 1 Pa-m or 39 
bar-meters (peak-to-peak) - will be from an airgun array 
with a air discharge volume of 1,210 in3. This compares to 
the 1,500 in3 array used on Western Geophysical's primary 
source vessel in 1998 and will be the only airgun array used by Western 
Geophysical in the Beaufort Sea this year.
    It is anticipated that 34 seismic lines will be run for each patch, 
covering an area 5.0 km by 15.7 km (2.7 nm by 8.1 nm), centered over 
the patch. Source lines for one patch will overlap with those for 
adjacent patches.
    After sufficient data have been recorded to allow accurate mapping 
of the rock strata, the cables are lifted onto the deck of a cable-
retrieval vessel, moved to a new location (ranging from several hundred 
to a few thousand feet away), and placed onto the seabed again. For a 
more detailed description of the seismic operation, please refer to the 
1999 application from Western Geophysical.
    Depending upon ambient noise conditions and the sensitivity of the 
receptor, underwater sounds produced by open water seismic operations 
may be detectable a substantial distance away from the activity. Any 
sound that is detectable is (at least in theory) capable of eliciting a 
disturbance reaction by a marine mammal or of masking a signal of 
comparable frequency (Western Geophysical, 1999). 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 react to the generated sounds or to visual cues.
     Seismic pulses are known to cause strong avoidance reactions by 
many of the bowhead whales occurring within a distance of several 
kilometers and may sometimes cause avoidance or other changes in 
bowhead behavior at considerably greater distances (Richardson et al., 
1995; Rexford, 1996; MMS, 1997). Results from the 1996-1998 BP and 
Western Geophysical seismic program monitoring indicate that most 
bowheads avoided an area within about 20 km (10.8 nm) of nearshore 
seismic operations (Miller et al., 1998, 1999). It is also possible 
that seismic pulses may disturb some other marine mammal species 
occurring in the area.
    Although some limited masking of low-frequency sounds (e.g., whale 
calls) is a possibility, the intermittent nature of seismic source 
pulses (1 second in duration every 16 to 24 seconds) 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 (LGL and Greeneridge, 1997, 1998, 1999a; Richardson et 
al., 1986). Masking effects are expected to be absent in the case of 
belugas, given that sounds important to them are predominantly at much 
higher frequencies than are airgun sounds (Western Geophysical, 1999).
    Hearing damage is not expected to occur during the project. It is 
not positively known whether the hearing systems of marine mammals very 
close to an airgun might be subject to temporary or permanent hearing 
impairment (Richardson et al., 1995). However, planned monitoring and 
mitigation measures (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.
    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 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.

Bowhead Whales

    Various studies (Reeves et al., 1984, Fraker et al., 1985, 
Richardson et al., 1986, Ljungblad et al., 1988) have reported that, 
when an operating seismic vessel approaches within a few kilometers, 
most bowhead whales exhibit strong avoidance behavior and changes in 
surfacing, respiration, and dive cycles. In studies prior to 1996, 
bowheads exposed to seismic pulses from vessels more than 7.5 km (4.0 
nm) away rarely showed observable avoidance of the vessel, but their 
surface, respiration, and dive cycles appeared altered in a manner 
similar to that observed in whales exposed at a closer distance 
(Western Geophysical, 1999).
    Within a 6- to 99-km (3.2 to 53.5 nm) range, it has not been 
possible to determine a specific distance at which subtle behavioral 
changes no longer occur (Richardson and Malme, 1993), given the high 
variability observed in bowhead whale behavior (Western Geophysical, 
1999). However, in three studies of bowhead whales and one of gray 
whales, surfacing-dive cycles have been unusually rapid in the presence 
of seimic noise, with fewer breaths per surfacing and longer intervals 
between breaths (Richardson et al., 1986; Koski and Johnson, 1987; 
Ljungblad et al., 1988; Malme et al., 1988). This pattern of subtle 
effects was evident among bowheads 6 km to at least 73 km (3.2 to 39 
nm) from seismic vessels. However, in the pre-1996 studies, active 
avoidance usually was not apparent unless the seismic vessel was closer 
than about 6 to 8 km (3.2 to 4.3 nm)(Western Geophysical, 1999).
    Inupiat whalers believe that migrating bowheads are sometimes 
displaced at distances considerably greater than 6 to 8 km (3.3 to 4.3 
nm)(Rexford, 1996). Also, whalers have mentioned that bowheads 
sometimes seem more ``skittish'' and more difficult to approach when 
seismic exploration is underway in the area. It is possible that, when 
additional data are available and analyzed, it may be demonstrated that 
isolated bowheads avoid seismic vessels at distance beyond 20 km (10.8 
nm). Also, the ``skittish'' behavior may be related to the observed 
subtle changes in the behavior of bowheads exposed to seismic pulses 
from distant seismic vessels (Richardson et al., 1986).

Gray Whales

    The reactions of gray whales to seismic pulses are similar to those 
of bowheads. Migrating gray whales along the California coast were 
noted to slow their speed of swimming, turn away from seismic noise 
sources, and increase their respiration rates. Malme et al. (1983, 
1984, 1988) concluded that approximately 50 percent showed avoidance 
when the average received

[[Page 28994]]

pulse level was 170 dB (re 1 Pa). By some behavioral measures, 
clear effects were evident at average pulse levels of 160+dB; less 
consistent results were suspected at levels of 140-160 dB. Recent 
research on migrating gray whales showed responses similar to those 
observed in the earlier research when the source was moored in the 
migration corridor 2 km (1.1 nm) from shore. However, when the source 
was placed offshore (4 km (2.2 nm) from shore) of the migration 
corridor, the avoidance response was not evident on track plots (Tyack 
and Clark. 1998).

Beluga

    The beluga is the only species of toothed whale (Odontoceti) 
expected to be encountered in the Beaufort Sea. Because their hearing 
threshold at frequencies below 100 Hz (where most of the energy from 
airgun arrays is concentrated) is poor (125 dB re 1 Pa @ 1 m) 
or more depending upon frequency (Johnson et al., 1989; Richardson et 
al., 1991, 1995), beluga are not predicted to be strongly influenced by 
seismic noise. However, because of the high source levels of seismic 
pulses, airgun sounds sometimes may be audible to beluga at distances 
of 100 km (54 nm)(Richardson and Wursig, 1997). The reaction distance 
for beluga, although presently unknown, is expected to be less than 
that for bowheads, given the presumed poorer sensitivity of belugas 
than that of bowheads for low-frequency sounds (Western Geophysical, 
1999).

Ringed, Largha and Bearded Seals

    No detailed studies of reactions by seals to noise from open water 
seismic exploration have been published (Richardson et al., 1995). 
However, there are some data on the reactions of seals to various types 
of impulsive sounds (LGL and Greeneridge, 1997, 1998, 1999a; J. Parsons 
as quoted in Greene, et al. 1985; Anon., 1975; Mate and Harvey, 1985). 
These studies indicate that ice seals typically either tolerate or 
habituate to seismic noise produced from open water sources.
    Underwater audiograms have been obtained using behavioral methods 
for three species of phocinid seals, ringed, harbor, and harp seals 
(Pagophilus groenlandicus). These audiograms were reviewed in 
Richardson et al. (1995) and Kastak and Schusterman (1998). Below 30-50 
kHz, the hearing threshold of phocinids is essentially flat down to at 
least 1 kHz and ranges between 60 and 85 dB (re 1 Pa @ 1 m). 
There are few data on hearing sensitivity of phocinid seals below 1 
kHz. NMFS considers harbor seals to have a hearing threshold of 70-85 
dB at 1 kHz (60 FR 53753, October 17, 1995), and recent measurements 
for a harbor seal indicate that, below 1 kHz, its thresholds 
deteriorate gradually to 97 dB (re 1 Pa @ 1 m) at 100 Hz 
(Kastak and Schusterman, 1998).
    While no detailed studies of reactions of seals from open-water 
seismic exploration have been published (Richardson et al., 1991, 
1995), some data are available on the reactions of seals to various 
types of impulsive sounds (see LGL and Greeneridge, 1997, 1998, 1999a; 
Thompson et al. 1998). These references indicate that it is unlikely 
that pinnipeds would be harassed or injured by low frequency sounds 
from a seismic source unless they were within relatively close 
proximity of the seismic array. For permanent injury, pinnipeds would 
likely need to remain in the high-noise field for extended periods of 
time. Existing evidence also suggests that, while seals may be capable 
of hearing sounds from seismic arrays, they appear to tolerate intense 
pulsatile sounds without known effect once they learn that there is no 
danger associated with the noise (see, for example, NMFS/Washington 
Department of Wildlife, 1995). In addition, they will apparently not 
abandon feeding or breeding areas due to exposure to these noise 
sources (Richardson et al., 1991) and may habituate to certain noises 
over time. Since seismic work is fairly common in Beaufort Sea waters, 
pinnipeds have been previously exposed to seismic noise and may not 
react to it after initial exposure.
    For a discussion on the anticipated effects of ships, boats, and 
aircraft, on marine mammals and their food sources, please refer to the 
application (Western Geophysical, 1999). Information on these effects 
is incorporated in this document by citation.

Numbers of Marine Mammals Expected to Be Taken

    Western Geophysical estimates that the following numbers of marine 
mammals may be subject to Level B harassment, as defined in 50 CFR 
216.3:

 
------------------------------------------------------------------------
                                      Population     Harassment Takes in
                                   ----------------         1999
              Species                              ---------------------
                                         Size       Possible
                                                               Probable
------------------------------------------------------------------------
Bowhead...........................           9,900
160 dB criterion..................                     1,000        <500
20 km criterion...................                     2,500       1,250
Gray whale........................          26,600       <10           0
Beluga............................          39,258       250        <150
Ringed seal*......................   1-1.5 million       400        <200
Spotted seal*.....................        >200,000        10          <2
Bearded seal*.....................        >300,000        50         <15
------------------------------------------------------------------------
* Some individual seals may be harassed more than once.

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, ringed seals, 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 bowheads become more skittish when exposed to 
seismic noise.
    Nuiqsut is the community closest to the area of the proposed 
activity, and it harvests bowhead whales only during the fall whaling 
season. In recent years,

[[Page 28995]]

Nuiqsut whalers typically take two to four whales each season (Western 
Geophysical, 1999). 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 
seismic area. Thus, the possibility and timing of potential seismic 
operations in the Cross Island area requires Western Geophysical to 
provide NMFS with either a Plan of Cooperation with North Slope Borough 
residents or to identify measures that have been or will be taken to 
avoid any unmitigable adverse impact on subsistence needs. Western 
Geophysical's application has identified those measures that will be 
taken to minimize any adverse effect on subsistence. In addition, the 
timing of seismic operations in and east of the Cross Island area will 
be addressed in a Conflict and Avoidance Agreement (C&AA) with the 
Nuiqsut whalers and the AEWC (Western Geophysical, 1999).
    Whalers from the village of Kaktovik search for whales east, north, 
and west of the village. Kaktovik is located 60 km (32.4 nm) east of 
the easternmost end of Western Geophysical's planned 1999 seismic 
exploration area. The westernmost reported harvest location was about 
21 km (11.3 nm) west of Kaktovik, near 70o10'N, 
144oW (Kaleak, 1996). That site is approximately 40 km (21.6 
nm) east of the closest part of Western Geophysical's planned seismic 
exploration area for 1999 (Western Geophysical, 1999).
    Whalers from the village of Barrow search for bowhead whales much 
further from the planned seismic area, >200 km (>108 nm) west (Western 
Geophysical, 1999).
    The location of the proposed seismic activity is south of the 
center of the westward migration route of bowhead whales, but there is 
some overlap. Seismic monitoring results from 1996-1998 indicate that 
most bowheads avoid the area within about 20 km (11 nm) around the 
array when it is operating. In addition, bowheads may be able to hear 
the sounds emitted by the seismic array out to a distance of 50 km (27 
nm) 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. Western Geophysical (1999) believes it is 
unlikely that changes in migration route will occur at distances 
greater than 25 km (13 nm) from an array of maximum volume of 1,210 
in3 operating in water less than 30 m (100 ft) deep. 
However, subtle changes in behavior might occur out to longer 
distances. Inupiat whalers believe that bowheads begin to divert from 
their normal migration path more than 35 miles away (MMS, 1997).
    It is recognized that it is difficult to determine the maximum 
distance at which reactions occur (Moore and Clark, 1992). As a result, 
Western Geophysical will participate in a C&AA with the whalers to 
reduce any potential interference with the hunt. Also, it is believed 
that the monitoring plan proposed by Western Geophysical (1999; also 
see LGL Ltd. and Greeneridge Sciences Inc, 1999b) will provide 
information that will help resolve uncertainties about the effects of 
seismic exploration on the accessibility of bowheads to hunters.
    Many Nuiqsut hunters hunt seals intermittently year-round. However, 
during recent years, most seal hunting has been during the early summer 
in open water. In summer, boat crews hunt ringed, spotted and bearded 
seals. The most important sealing area for Nuiqsut hunters is off the 
Colville delta, extending as far west as Fish Creek and as far east as 
Pingok Island. This area overlaps with the westernmost portion of the 
planned seismic area. In this area, during summer, sealing occurs by 
boat when hunters apparently concentrate on bearded seals. However, 
these subsistence hunters have not perceived any interference between 
recent open-water seismic activities in the Alaskan Beaufort Sea. 
Therefore, because Western Geophysical is proposing similar mitigation 
and consultation procedures this year, it is unlikely that seismic 
activities would have more than a negligible impact on Nuiqsut seal 
hunting.

Mitigation

    This year, Western Geophysical will reduce its airgun array from 
the 1,500 in3 used in 1998 to 1,210 in3 and 
investigate whether it is practical to modify the design to reduce 
horizontal propagation of sound. These changes are expected to result 
in lower received levels and therefore smaller safety ranges and 
reduced takes by harassment than in 1998. However, because the 1,210 
in3 array is a subset (with some minor variations) of the 
1,500 in3 array (with 4 guns not firing), NMFS proposes to 
prohibit Western Geophysical from firing more than the 8 airguns that 
total 1,210 in3 during the 1999 open water seismic survey 
without an amendment to the IHA (if issued).
    Vessel-based observers will monitor marine mammal presence in the 
vicinity of the seismic array throughout the seismic program. To avoid 
the potential for serious injury to marine mammals, Western Geophysical 
proposes to power down the seismic source if pinnipeds are sighted 
within the area delineated by the 190 dB isopleth or 240 m (787.4 ft) 
from the array operating at 5 m (16.4 ft) depth or 80 m (262.5 ft) from 
the array operating at 2 m (6.6 ft) depth. Western 
Geophysical will power down the seismic source if bowhead, gray, or 
beluga whales are sighted within the area delineated by the 180 dB 
isopleth or within 750 m (2,460.6 ft) of the array operating at 5 m ( 
16.4 ft) depth or 360 m (1,181.1 ft) of the array operating at 2 m (6.6 
ft) depth. However, because these safety zones were based on the 1998 
array configuration, within the first 10 days of Beaufort Sea 
operations in 1999, Western Geophysical will measure and analyze the 
sounds from Western's 1999 array operating at both 5 m (16.4 ft) and 2 
m (6.6 ft) depths. This information will be provided to NMFS, along 
with the contractor's recommendation as to whether any adjustments in 
the safety radii are needed to meet the 190 and 180 dBrms 
shutdown criteria.
    In addition, Western Geophysical proposes to ramp-up the seismic 
source to operating levels at a rate no greater than 6 dB/min anytime 
the array has not been firing for 1-2 minutes (depending upon vessel 
speed). Ramp-up will begin with an air volume discharge not exceeding 
80 in3 with additional guns added at intervals appropriate 
to limit the rate of increase to 6 dB/min.

Monitoring

    As part of its application, Western Geophysical provided a 
monitoring plan for assessing impacts to marine mammals from seismic 
surveys in the Beaufort Sea. This monitoring plan is described in 
Western Geophysical (1999) and in LGL Ltd. and Greeneridge Sciences 
Inc. (1999b). As required by the MMPA, this monitoring plan will be 
subject to a peer-review panel of technical experts prior to formal 
acceptance by NMFS.
    Preliminarily, Western Geophysical plans to conduct the following:

Vessel-based Visual Monitoring

    It is proposed that one or two biologist-observers aboard the 
seismic vessel will search for and observe marine mammals whenever 
seismic operations are in progress, and for at least 30 minutes prior 
to planned start of shooting. These observers will scan the area 
immediately around the vessels with reticle binoculars during the 
daytime supplemented with night-vision equipment during the night 
(prior to mid-August, there are no hours of

[[Page 28996]]

darkness). In addition, Western Geophysical proposes to experiment with 
the illumination of the safety zone with high-intensity lighting this 
year.
    A total of four observers (three trained biologists and one Inupiat 
observer/communicator) will be based aboard the seismic vessel. Use of 
four observers is an increase over 1998 and will allow two observers to 
be on duty simultaneously for up to 50 percent of the active airgun 
hours. Use of two observers will increase the probability of detecting 
marine mammals and two observers will be required to be on duty 
whenever the seismic array is ramped up. Individual watches will 
normally be limited to no more than 4 consecutive hours.
    When mammals are detected within or about to enter the safety zone 
designated to prevent injury to the animals (see Mitigation), the 
geophysical crew leader will be notified so that shutdown procedures 
can be implemented immediately.

Aerial Surveys

    If the seismic program continues after August 31, Western 
Geophysical proposes to conduct daily aerial surveys, weather 
permitting, from September 4, 1999, until September 20, 1999, or until 
1 day after the seismic program ends, if earlier than September 20. 
This reduction in survey effort is considered appropriate because some 
of the main questions about disturbance to bowheads from a nearshore 
seismic operation have been answered previously.
    The primary objective will be to document the occurrence, 
distribution, and movements of bowhead 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. Aerial surveys will be 
at an altitude of 300 m (1,000 ft) above sea level. Western Geophysical 
proposes to fly at 457 m (1500 ft) altitude over areas where whaling is 
occurring on that date and to avoid direct overflights of whaleboats 
and Cross Island, where whalers from Nuiqsut are based during their 
fall whale hunt.
    The daily aerial surveys are proposed to cover a grid of 14 north-
south lines spaced 8 km (4.3 nm) apart and will extend seaward to about 
the 100 m (328 ft) depth contour (typically about 65 km (35 nm) 
offshore. This grid will extend from about 40 km (22 nm) east to 40 km 
(22 nm) west of the area in which seismic operations are underway on 
that date. This design will provide extended coverage to the west to 
determine the westward extent of the offshore displacement of whales by 
seismic. In 1999, no ``intensive'' grid surveys are planned, as 
conducted in previous years.
    Detailed information on the survey program can be found in Western 
Geophysical (1999) and in LGL Ltd. and Greeneridge Sciences Inc. 
(1999b), which are incorporated in this document by citation.

Acoustical Measurements

    The acoustic measurement program proposed for 1999 is designed to 
be continue work conducted in 1996 through 1998 (see LGL and 
Greeneridge Sciences Inc., 1997, 1998, 1999a). The acoustic measurement 
program is planned to include (1) vessel-based acoustic measurements, 
(2) OBC-based acoustic measurements, (3) use of air-dropped sonobuoys 
and (4) bottom-mounted acoustical recorders.
    (1) A vessel-based acoustical measurement program is proposed for a 
few days early in the seismic program. The objectives of this survey 
will be as follows: (a) To measure the levels and other characteristics 
of the horizontally propagating seismic survey sounds from the type of 
airgun array to be used in 1999 as a function of distance and aspect 
relative to the seismic source vessel and in relation to the operating 
depth of the airguns, and (b) to measure the levels and frequency 
composition of the vessel sounds emitted by vessels used regularly 
during the 1999 program in those cases when these vessels have not 
previously been measured adequately.
    (2) Western Geophysical and its proposed consultant (Greeneridge 
Sciences) will use recorded signals from Western's OBC system to help 
document horizontal propagation of the seismic survey pulses.
    (3) Sonobuoys will be dropped and monitored from bowhead survey 
aircraft during September 4 through 20, 1999 (if the seismic operations 
are continuing at that time). Sonobuoys will provide data on 
characteristics of seismic pulses (and signal-to-ambient ratios) at 
offshore locations, including some of those places where bowhead whales 
are observed.
    (4) Autonomous seafloor acoustic recorders will be placed on the 
sea bottom at three locations to record low-frequency sounds nearly 
continuously for up to 3 weeks at a time during September (if seismic 
operations are continuing at that time). Information includes 
characteristics of the seismic pulses, ambient noise, and bowhead 
calls.
    For a more detailed description of planned monitoring activities, 
please refer to the application and supporting document (Western 
Geophysical, 1999; LGL Ltd. and Greeneridge Sciences Inc., 1999b).

Estimates of Marine Mammal Take

    Estimates of takes by harassment will be made through vessel and 
aerial surveys. Preliminarily, Western Geophysical will estimate the 
number of (a) marine mammals observed within the area ensonified 
strongly by the seismic vessel; (b) marine mammals observed showing 
apparent reactions to seismic pulses (e.g., heading away from the 
seismic vessel in an atypical direction); (c) marine mammals subject to 
take by type (a) or (b) here when no monitoring observations were 
possible; and (d) bowheads displaced seaward from the main migration 
corridor.

Reporting

    Western Geophysical will provide an initial report on 1999 
activities to NMFS within 90 days of the completion of the seismic 
program. This report will provide dates and locations of seismic 
operations, details of marine mammal sightings, estimates of the amount 
and nature of all takes by harassment, and any apparent effects on 
accessibility of marine mammals to subsistence users.
    A final technical report will be provided by Western Geophysical 
within 20 working days of receipt of the document from the contractor, 
but no later than April 30, 2000. 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 
an informal consultation on the issuance of an IHA for similar 
activities on July 23, 1998. If an authorization to incidentally harass 
listed marine mammals is issued under the MMPA, NMFS will issue an 
Incidental Take Statement under section 7 of the ESA.

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 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

[[Page 28997]]

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.
    While this year's activity is a continuation of the seismic work 
conducted between 1996 and 1998, NMFS determined that a new EA was 
warranted based on the proposed construction of the Northstar project, 
the collection of data from 1996 through 1998 on Beaufort Sea marine 
mammals and the impacts of seismic activities on these mammals, and the 
analysis of scientific data indicating that bowheads avoid nearshore 
seismic operations by up to about 20 km (10.8 nm). Accordingly, a 
review of the impacts expected from the issuance of an IHA has been 
assessed in detail in the EA and in this document, and NMFS has 
preliminarily determined that there will be no more than a negligible 
impact on marine mammals from the issuance of the harassment 
authorization and that there will not be any unmitigable impacts to 
subsistence communities, provided the mitigation measures required 
under the authorization are implemented.

Conclusions

    NMFS has preliminarily determined that the short-term impact of 
conducting seismic surveys in the U.S. Beaufort Sea will result, at 
worst, in a temporary modification in behavior by certain species of 
cetaceans and possibly pinnipeds. While behavioral modifications may be 
made by these species to avoid the resultant noise, this behavioral 
change is expected to have a negligible impact on the animals.
    While the number of potential incidental harassment takes will 
depend on the distribution and abundance of marine mammals (which vary 
annually due to variable ice conditions and other factors) in the area 
of seismic operations, due to the distribution and abundance of marine 
mammals during the projected period of activity and the location of the 
proposed seismic activity 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. In 
addition, no take by injury and/or death is anticipated, and the 
potential for temporary or permanent hearing impairment will be avoided 
through the incorporation of the mitigation measures mentioned in this 
document. No rookeries, mating grounds, 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.
    Because bowhead whales are east of the seismic area in the Canadian 
Beaufort Sea until late August/early September, seismic activities are 
not expected to impact subsistence hunting of bowhead whales prior to 
that date. After September 4, 1999, aerial survey flights for bowhead 
whale assessments will be initiated. Appropriate mitigation measures to 
avoid an unmitigable adverse impact on the availability of bowhead 
whales for subsistence needs will be the subject of consultation 
between Western Geophysical and subsistence users.
    Also, while open-water seismic exploration in the U.S. Beaufort Sea 
has some potential to influence seal hunting activities by residents of 
Nuiqsut, because (1) the peak sealing season is during the winter 
months, (2) the main summer sealing is off the Colville Delta, and (3) 
the zone of influence by seismic sources on beluga and seals is fairly 
small, NMFS believes that Western Geophysical's seismic survey will not 
have an unmitigable adverse impact on the availability of these stocks 
for subsistence uses.

Proposed Authorization

    NMFS proposes to issue an IHA for the 1999 Beaufort Sea open water 
season for a seismic survey provided the above mentioned mitigation, 
monitoring, and reporting requirements are incorporated. NMFS has 
preliminarily determined that the proposed seismic activity would 
result in the harassment of only small numbers of bowhead whales, 
beluga whales, ringed seals, bearded seals, and possibly spotted seals 
and gray whales; would have a negligible impact on these marine mammal 
stocks; and would not have an unmitigable adverse impact on the 
availability of marine mammal stocks for subsistence uses.

Information Solicited

    NMFS requests interested persons to submit comments, and 
information, concerning this request (see ADDRESSES).

    Dated: May 21, 1999.
Hilda Diaz-Soltero,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 99-13565 Filed 5-27-99; 8:45 am]
BILLING CODE 3510-22-F