[Federal Register Volume 63, Number 97 (Wednesday, May 20, 1998)]
[Notices]
[Pages 27709-27714]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-13425]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration
[I.D. 051498A]


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 1998.

DATES: Comments and information must be received no later than June 19, 
1998.

ADDRESSES: Comments on the application should be addressed to Michael 
Payne, Chief, Marine Mammal Division, Office of Protected Resources, 
NMFS, 1315 East-West Highway, Silver Spring, MD 20910-3225. A copy of 
the application, a 1996 environmental assessment (EA), and a list of 
references used in this document 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

     Section 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
directs 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 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 April 15, 1998, 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 Harrison Bay and Flaxman Island, AK. Weather 
permitting, the survey is expected to take place between approximately 
July 1 and October 20, 1998. A detailed description of the work 
proposed for 1998 is contained in the application (Western Geophysical, 
1998) 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 (Minerals Management Service (MMS), 
1992, 1996). This information is incorporated by reference 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), belukha (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 several other documents 
(Western Geophysical, 1998; BPXA, 1996b, 1998; Lentfer, 1988;

[[Page 27710]]

MMS, 1992, 1996; Small and DeMaster, 1995; 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 secondary 
source of noise. The physical presence of vessels and aircraft could 
also lead to non-acoustic effects 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. OBC surveys involve dropping cables from a 
ship to the ocean bottom, forming a patch consisting of 4 parallel 
cables 10 kilometers (km) (6.2 mi) long, separated 750 m (2,500 ft) 
from each other. Sensors (hydrophones) are attached to the cables. 
These hydrophones are used to detect seismic energy reflected back from 
underground rock strata. The original 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 249 dB re 1 Pa-m (zero to peak) or 
53 bar-meters peak-to-peak from a 1,500 in3 array of 
airguns--is in the lower to middle portion of the range of source 
levels commonly used for seismic operations with airgun arrays 
(Richardson et al., 1995). Normally, 36 seismic lines are run for each 
patch, covering an area 6.0 km by 17.5 km (3.7 mi by 10.87 mi), 
centered over the patch.
    After sufficient data have been recorded to allow accurate mapping 
of the rock strata, the cable is 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 
application (Western Geophysical, 1998).
    Depending upon ambient 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, 1998). 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 bowhead whales to behaviorally 
respond within a distance of several kilometers (Richardson et al., 
1995). 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 6 to 12 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 (Richardson et al., 1986). Masking effects are 
expected to be absent in the case of belukhas, given that sounds 
important to them are predominantly at much higher frequencies than are 
airgun sounds (Western Geophysical, 1998).
    Hearing damage is not expected to occur during the project. It is 
not known whether a marine mammal very close to an airgun array would 
be at risk of temporary or permanent hearing impairment, but temporary 
threshold shift is a theoretical possibility for animals within a few 
hundred meters (Richardson et al., 1995) of the source. However, 
planned monitoring and mitigation measures (described later in this 
document) are designed to detect marine mammals occurring near the 
array and to avoid exposing them to sound pulses that have any 
possibility of causing hearing damage.
    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 (Western Geophysical, 1998).

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. Bowheads exposed to seismic 
pulses from vessels more than 7.5 km (4.5 mi) 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 (BPXA, 1996a, 1996b, Western 
Geophysical, 1998).
    Within a 6-99 km (3.7-60 mi) 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 (BPXA, 1996a, 1996b). Analysis of 
the results from BPXA's 1996 seismic monitoring program does not 
provide conclusive evidence about the radius of avoidance of bowheads 
to the seismic program. The peak number of bowhead sightings was 10-20 
km (6.2-12.3 mi) from shore during no-seismic periods and 20-30 km 
(12.3-18.6 mi) from shore during periods that may have been influenced 
by seismic noise. This difference was not statistically significant, 
but the low numbers of sightings preclude meaningful interpretation 
(Western Geophysical, 1998).
    Inupiat whalers believe that migrating bowheads are sometimes 
displaced at distances considerably greater than 6 to 8 km (3.7 to 5.0 
mi)(Rexford, 1996). Scientific studies done to date have limitations as 
discussed in part by Moore and Clark (1992) and MMS (1996). It is 
possible that, when additional data are available, it will be 
demonstrated that bowheads sometimes do avoid seismic vessels at 
distances beyond 6 to 8 km (3.7 to 5.0 mi). Also, whalers have 
mentioned that bowheads sometimes seem more ``skittish'' and more 
difficult to approach when seismic exploration is underway in the area. 
This ``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 27711]]

pulse level was 170 dB (re 1 Pa @ 1 m). 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.

Belukha

    The belukha 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), belukha are not predicted to be strongly influenced 
by seismic noise. However, because of the high source levels of seismic 
pulses, airgun sounds may be audible to belukha at distances of 100 km 
(Richardson and Wursig, 1997). The reaction distance for belukha, 
although presently unknown, is expected to be less than that for 
bowheads, given the presumed poorer sensitivity of belukhas than that 
of bowheads for low-frequency sounds (Western Geophysical, 1998).

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 (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). 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, 1995a, b).
    Because no studies to date have focused on pinniped reaction to 
underwater noise from pulsed, seismic arrays in open water (Richardson 
et al., 1991, 1995), as opposed to in-air exposure to continuous noise, 
substantive conclusions are not possible at this time. However, 
assuming a sound pressure level of 80-100 dB over its threshold is 
needed in order to cause annoyance and 130 dB for injury (pain), as is 
the current thought based upon human studies (Advanced Research 
Projects Agency and NMFS, 1995), it appears unlikely that pinnipeds 
would be harassed or injured by low frequency sounds from a seismic 
source unless they were within close proximity of the 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 they may be capable of hearing sounds from seismic 
arrays, seals 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.

Other Effects

    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, 1998). Information on these effects 
is incorporated in this document by reference (see Western Geophysical, 
1998).

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:

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                                                                                        Harassment takes in 1998
                    Species                                 Population size            -------------------------
                                                                                          Possible     Probable 
----------------------------------------------------------------------------------------------------------------
Bowhead.......................................  8,000.................................          800         <400
Gray whale....................................  23,000................................          <10            0
Belukha.......................................  41,610................................          250         <150
Ringed seal...................................  1-1.5 million.........................          400         <300
Spotted seal..................................  >200,000..............................           10           <5
Bearded seal..................................  >300,000..............................           50          <30
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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 (Western Geophysical, 1998). 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 (Western Geophysical, 1998).
    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, Nuiqsut whalers typically take zero to four 
whales each season (Western Geophysical, 1998). 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 a Plan of Cooperation 
(also called the Communications and Avoidance Agreement) with North 
Slope Borough residents to avoid any unmitigable adverse impact on 
subsistence needs.
    Whalers from the village of Kaktovik search for whales east, north, 
and west

[[Page 27712]]

of the village. Kaktovik is located 50 mi (80 km) east of the 
easternmost end of Western Geophysical's planned 1998 seismic 
exploration area. The westernmost reported harvest location was about 
21 km (13 mi) west of Kaktovik, near 70 deg.10'N, 144 deg.W (Kaleak, 
1996). That site is approximately 60 km (37 mi) east of the closest 
part of Western Geophysical's planned seismic exploration area for 1998 
(Western Geophysical, 1998).
    Whalers from the village of Barrow search for bowhead whales much 
further from the planned seismic area, >200 km (>125 mi) west (Western 
Geophysical, 1998).
    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. Western Geophysical (1998) believes that, although whales 
may be able to hear the sounds emitted by the seismic array out to a 
distance of 50 km (30 mi) or more, it is unlikely that changes in 
migration route will occur at distances of >25 km (>15 mi). 
Alternatively, Inupiat whalers believe that bowheads begin to divert 
from their normal migration path more than 48 km (35 mi) away (MMS, 
1996).
    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 Communications and Avoidance 
Agreement with the whalers to reduce any potential interference with 
the hunt. Also, it is believed that the monitoring plan proposed by 
Western Geophysical (1998; also see LGL Ltd. and Greeneridge Sciences 
Inc, 1998) will provide information that will help resolve 
uncertainties about the effects of seismic exploration on the 
accessibility of bowheads to hunters.
    While seismic exploration has some potential to influence 
subsistence seal hunting activities, the peak season for seal hunting 
is during the winter months when the harvest consists almost 
exclusively of ringed seals (Western Geophysical, 1998). In summer, 
boat crews hunt ringed, spotted and bearded seals (Western Geophysical, 
1998). 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 (Western Geophysical, 1998). 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 (Western Geophysical, 1998).

Mitigation

    Western Geophysical plans to use biological observers to monitor 
marine mammal presence in the vicinity of the seismic array. To avoid 
the potential for serious injury to marine mammals, Western Geophysical 
will power down the seismic source if pinnipeds are sighted within the 
area delineated by the 190 dB isopleth or:
    (1) within 60 m (197 ft) of a single airgun or an array of 
60 in3.
    (2) within 170 m (558 ft) of an array >60 in\3\ and 750 
in\3\ at <2.5 m (8.3 ft) depth;
    (3) within 280 m (919 ft) of an array >60 in\3\ and 750 
in\3\ operating at >2.5 m (8.3 ft) depth;
    (4) within 200 m (656 ft) of an array >750 in\3\ and 
1500 in\3\ operating at <2.5 m (8.3 ft) depth;
    (5) within 350 m (1,148 ft) of an array >750 in\3\ and 
1500 in\3\ operating at >2.5 m (8.3 ft) depth;
    Western Geophysical will power down the seismic source if bowhead, 
gray, or belukha whales are sighted within the area delineated by the 
180 dB isopleth or:
    (1) within 160 m (525 ft) of a single airgun or an array of >60 
in\3\;
    (2) within 660 m (2,165 ft) of an array >60 in\3\ and 
750 in\3\ at <2.5 m (8.3 ft) depth;
    (3) within 900 m (2,953 ft) of an array >60 in\3\ and 
750 in\3\ operating at >2.5 m (8.3 ft) depth;
    (4) within 700 m (2,297 ft) of an array >750 in\3\ and 
840 in\3\ operating at <2.5 m (8.3 ft) depth; and
    (5) within 900 m (2,953 ft) of an array >750 in\3\ and 
840 in\3\ operating at >2.5 m (8.3 ft) depth;
    In addition, Western Geophysical proposes to ramp-up the seismic 
source to operating levels at a rate no greater than 6 dB/min. If the 
array includes airguns of different sizes, the smallest gun will be 
fired first. Additional guns will be added at intervals appropriate to 
limit the rate of increase in source level to a maximum of 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 (1998) and in LGL Ltd. and Greeneridge Sciences 
Inc. (1998). Although Western Geophysical is prepared to discuss 
coordination of research to the extent practicable with other seismic 
operations, Western Geophysical is prepared to sponsor an independent 
program. 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

    A minimum of 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 reticulated binoculars during the daytime and with night-
vision equipment during the night (prior to mid-August, there are no 
hours of darkness). Individual watches will normally be limited to no 
more than 4 consecutive hours.
    When mammals are detected within a 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

    From September 1, 1998, until 3 days after the seismic program 
ends, aerial surveys will be conducted daily, weather permitting. The 
primary objective will be to document the occurrence, distribution, and 
movements of bowhead and belukha 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 avoid overflights of the Cross 
Island area where whalers from Nuiqsut are based during their fall 
whale hunt.
    Consistent with 1996 and 1997 aerial surveys in the U.S. Beaufort 
Sea, the daily aerial surveys are proposed to cover two grids: (1) A 
grid of 12 north-south lines spaced 8 km (5 mi) apart and extending 
from about 20 km (12.5 mi) west of the western side of the then-current 
seismic exploration area to 50 km (30 mi) east of its eastern edge, and 
from the barrier islands north to approximately the 100 m (328 ft) 
depth contour; and (2) a grid of 4 survey lines within the above 
region, also spaced 8 km (5 mi) apart and mid-way between the longer 
lines, to provide more intensive coverage of the area of the seismic 
operations and immediate surrounding waters.

[[Page 27713]]

    When the seismic program is relocated east or west along the coast 
during the 1998 season, both survey grids will be relocated a 
corresponding distance along the coast. Information on the survey 
program can be found in Western Geophysical (1998) and in LGL Ltd. and 
Greeneridge Sciences Inc. (1998), which are incorporated in this 
document by reference.

Acoustical Measurements

    The acoustic measurement program proposed for 1998 is designed to 
be continue work conducted in 1996 and 1997 (see BPXA, 1996a, 1997, and 
1998; LGL Ltd. and Greeneridge Sciences Inc., 1996, 1997, and 1998). 
The acoustic measurement program is planned to include (1) boat-based 
acoustic measurements, (2) OBC-based acoustic measurements, (3) use of 
air-dropped sonobuoys and (4) bottom-mounted acoustical recorders.
    The boat-based acoustical measurement program is proposed for a 7-
day period in August 1998. The objectives of this survey will be as 
follows: (1) To measure the levels and other characteristics of the 
horizontally propagating seismic survey sounds from the type(s) of 
airgun array(s) to be used in 1998 as a function of distance and aspect 
relative to the seismic source vessel(s) and to water depth.
    (2) To measure the levels and frequency composition of the vessel 
sounds emitted by vessels used regularly during the 1998 program.
    (3) To obtain additional site-specific ambient noise data, which 
determine signal-to-noise ratios for seismic and other acoustic signals 
at various ranges from their sources.
    Western Geophysical and its proposed consultant (Greeneridge 
Sciences) are investigating the use of the OBC-system to help document 
horizontal propagation of the seismic surveys. In addition, during late 
August and September, autonomous seafloor acoustic recorders will be 
placed on the sea bottom at 3 locations to record low-frequency sounds 
nearly continuously for up to 3 weeks at a time. Information includes 
characteristics of the seismic pulses, ambient noise, and bowhead 
calls. Additional data on these noise sources will be obtained from 
sonobuoys dropped from aircraft after September 1.
    For a more detailed description of planned monitoring activities, 
please refer to the application and supporting document (Western 
Geophysical, 1998; LGL Ltd. and Greeneridge Sciences Inc., 1998).

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 (1) 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) 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 1998 
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, 1999. 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 incidental harassment 
authorization for similar activities on June 26, 1997. A copy of that 
document is available upon request (see ADDRESSES). 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 
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. A 
copy of the EA is available upon request (see ADDRESSES).
    This year's activity is a continuation of the seismic work 
conducted in 1996 and 1997. For Western Geophysical's 1998 application, 
NMFS has conducted a review of the impacts expected from the issuance 
of an Incidental Harassment Authorization in comparison to those 
impacts evaluated in 1996. As assessed in detail in this document, 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. Because the activity is 
substantially the same as the one conducted in 1996 and no new impacts 
on the environment have been identified, a new EA is not warranted and, 
therefore, the preparation of an Environmental Impact Statement on this 
action is not required by section 102(2) of NEPA or its implementing 
regulations.

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.
    As 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

[[Page 27714]]

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 August 31, 1998, 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 belukha 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 incidental harassment authorization for 
the 1998 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, gray whales, and possibly belukha whales, bearded 
seals, and largha seals; 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 14, 1998.
Patricia A. Montanio,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 98-13425 Filed 5-19-98; 8:45 am]
BILLING CODE 3510-22-F