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

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.

-----------------------------------------------------------------------

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:

----------------------------------------------------------------------------------------------------------------

Harassment takes in 1998

Species Population size -------------------------

Possible Probable

----------------------------------------------------------------------------------------------------------------

Bowhead....................................... 8,000................................. 800 200,000.............................. 10 300,000.............................. 50 200 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 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 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 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 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