[Federal Register Volume 64, Number 146 (Friday, July 30, 1999)]
[Notices]
[Pages 41384-41391]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-19462]
[[Page 41384]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 040799A]
Taking and Importing of Marine Mammals; Offshore Seismic
Activities in the Beaufort Sea
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of issuance of an incidental harassment authorization.
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SUMMARY: In accordance with provisions of the Marine Mammal Protection
Act (MMPA) as amended, notification is hereby given that an Incidental
Harassment Authorization (IHA) to take small numbers of bowhead whales
and other marine mammals by harassment incidental to conducting seismic
surveys in the Western Beaufort Sea in state and Federal waters has
been issued to Western Geophysical/Western Atlas International of
Houston, Texas (Western Geophysical).
DATES: Effective from July 20, 1999, until November 1, 1999, unless
extended.
ADDRESSES: The application, authorization, monitoring plan,
environmental assessment (EA), and a list of references used in this
document are available by writing to Donna Wieting, Chief, Marine
Mammal Conservation Division, Office of Protected Resources, NMFS, 1315
East-West Highway, Silver Spring, MD 20910-3225, or by telephoning one
of the contacts listed here.
FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, NMFS, (301)
713-2055, Brad Smith, NMFS, (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 (Secretary) to allow, upon request,
the incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a 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 if 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 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 northern 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).
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 geological 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 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). 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="" [[page="" 41385]]="" 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.="" results="" from="" the="" 1996-1998="" bp="" exploration="" (alaska)(bp)="" and="" western="" geophysical="" seismic="" monitoring="" program="" indicate="" that="" most="" bowheads="" avoided="" an="" area="" within="" about="" 20="" km="" (12.4="" mi)="" of="" nearshore="" seismic="" operations="" (miller="" et="" al.,="" 1998,="" 1999).="" the="" received="" levels="" of="" the="" seismic="" pulse="" at="" 20="" km="" range="" were="" about="" 115-="" 130="" db="" re="" 1="">Parms @ 1 m). 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, but apparently are limited to animals exposed to higher
levels of seismic pulses. 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 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 the beluga
hearing threshold at frequencies below 100 Hz (where most of the energy
from airgun arrays is concentrated) is poor (125 dB re 1 Pa)
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 96 dB (re 1 Pa @ 1 m) at 100 Hz
(Kastak and Schusterman, 1998).
Recent studies have provided some data are available on the
reactions of seals to various types of impulsive sounds (see LGL and
Greeneridge, 1997,
[[Page 41386]]
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:
------------------------------------------------------------------------
Harassment Takes in 1999
Species Population -------------------------
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="" 400=""><200 million="" 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,="" 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="" principal="" 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="" has="" been="" addressed="" in="" a="" conflict="" and="" avoidance="" agreement="" (c&aa)="" with="" the="" nuiqsut="" whalers="" and="" the="" alaska="" eskimo="" whaling="" commission="" (aewc).="" 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="">o10'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 (56 km) 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 are participating 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
[[Page 41387]]
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 from 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.
Comments and Responses
A notice of receipt of the application and proposed authorization
was published on May 28, 1999 (64 FR 28992), and a 30-day public
comment period was provided on the application and proposed
authorization. During the comment period, comments regarding this
application were received from the Marine Mammal Commission (MMC), LGL
Ltd. environmental research associates on behalf of the applicant, and
Greenpeace Alaska (Greenpeace).
MMPA Concerns
Comment 1: LGL Ltd provided information updating and correcting the
Federal Register notice that Western has no intention to use an array
larger than 1,210 in3 during 1999.
Response: Thank you for providing this information.
Comment 2: LGL Ltd questioned the statement in the Federal
Register document that the proposed seismic activity occurs in waters
generally too shallow and distant from the edge of the pack ice for
most marine mammals, and that this statement is not consistent with the
IHA Application and the EA. LGL notes that 5 of the 6 marine mammal
species requested for taking occur within the seismic area; only the
beluga remains (with a few exceptions) far offshore near the ice edge.
Response: NMFS agrees.
Comment 3: Greenpeace believes that NMFS and Western Geophysical
have failed to provide the evidence necessary to justify issuance of
the IHA by relying on outdated, incomplete and inaccurate information
on the zone of influence of seismic operations on bowhead whales.
Response: To make a determination of negligible impact on marine
mammal stocks or a finding of not having an unmitigable adverse impact
on subsistence uses of marine mammals, NMFS relies on the best
scientific information available. The latest scientific information has
been obtained through a 3-year program of data collection and analysis,
including aerial surveys and acoustic monitoring. Greenpeace does not
identify any additional sources of information not already considered
by NMFS or Western Geophysical. Western Geophysical's IHA application
and the notice of proposed authorization note that, in addition to the
known responses of bowhead whales out to a distance of several
kilometers, less conspicuous and/or less frequent effects may extend to
greater distances. The draft final monitoring report describing the
1996 through 1998 monitoring results (Richardson [ed.], 1999) shows
that (1) 1996, 1997 and 1998 seismic programs did not greatly influence
the position of the overall migration corridor; (2) the aerial surveys
showed avoidance of the area within 20 km (12 mi) of seismic
operations, plus partial avoidance of the area 20-30 km (12-19 mi)
away, and (3) based on 1998 research, there is no evidence that bowhead
disturbance extended 37 km (23 mi) offshore of the northern edge of the
seismic exploration area. For additional information on the estimated
zones that seismic airgun noise may have an effect on bowhead whales,
please refer to the proposed authorization notice mentioned in this
document.
Scientists, at least, recognize that it is difficult (for to
determine the maximum distance at which disturbance and avoidance
reactions may have an adverse impact on subsistence needs (Moore and
Clark, 1992). Inupiat whalers, on the other hand, believe that whales
exhibit avoidance reactions as far as 30 miles (48 km) away (MMS,
1997). As a result, Western Geophysical has developed 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 (LGL Ltd., LGL Alaska Research Associates, and Greeneridge,
1999), revised on the basis of comments received during this public
comment period and at the Peer-Review Workshop, will provide
information that will help resolve uncertainties about the effects of
seismic exploration on the bowhead whales and the accessibility of
bowheads to hunters.
Comment 4: Greenpeace believes the scientific evidence remains
inadequate to determine whether hearing or behavior of marine mammals
may be damaged temporarily or permanently by seismic operations. This
makes it impossible to put adequate mitigation measures into place when
there is inadequate knowledge about the impacts of seismic operations
on cetaceans' hearing and behavior.
Response: The impact of airguns on bowhead hearing and behavior has
been addressed in several documents, including Western Geophysical's
application, the supporting EA, and in LGL Ltd and Greeneridge Sciences
(1998) and most recently in LGL Ltd, LGL Alaska Research Associates,
and Greeneridge Sciences (1999). Without an ability to collect
empirical information on physical impacts from airguns on large marine
mammals, scientists must rely on surrogate species and make
conservative assumptions based upon findings for those species. For
bowhead and beluga whales, NMFS and Western Geophysical use the best
scientific information available which indicates that a safety zone set
at the 180 dB (re 1 Pa) isopleth will protect bowhead and
beluga whales from potential serious injury. Furthermore, the avoidance
reactions by bowheads and the offshore migration corridor of belugas
minimize the number of bowheads and belugas entering or approaching the
180 dB zone. Only one bowhead and no belugas have been seen in that
zone during the 1996, 1997, and 1998 monitoring projects (Richardson et
al., 1999). Because there are potential behavioral effects on bowhead
whales by seismic activities, an IHA is warranted. Under the IHA, NMFS
will require Western Geophysical to incorporate mitigation and
monitoring measures approved by the 1999 Peer Review Workshop
participants to reduce potential impacts on whales and seals to the
lowest level practicable.
Comment 5: Greenpeace notes that NMFS fails to place restrictions
on seismic operations during times of limited or zero visibility.
Response: Observers monitor the safety zones and zones of potential
harassment around the seismic source whenever visibility permits, and
the source is either on or within 30 minutes of powering up. This year
observers will be aided by high-intensity lighting for monitoring the
safety zone at night. Assessments of takes by harassment will be made
based upon the percentage of time spent observing in relation to the
total time for seismic operations. Because: (1) relatively few marine
mammals are expected in the area during the time of the survey, (2) the
vessels are underway at low speeds while conducting seismic surveys,
theoretically allowing animals sufficient time to move away from any
[[Page 41388]]
annoyances, and (3) documented observations indicate that bowhead
whales avoid active seismic survey areas, few marine mammals, and no
bowheads, are expected to approach the vessel. Therefore, terminating
surveys at night and during inclement weather is not warranted, in part
since to do so could extend the seismic season into the peak bowhead
migration period resulting in an increased level of harassment of that
species.
Comment 6: Greenpeace states that the issuance of an IHA will
result in significant and unmitigable impacts to subsistence
communities and the Arctic marine environment.
Response: Section 101(a)(5)(D)(i)(II) of the MMPA requires NMFS to
ensure that any taking will not have an unmitigable adverse impact on
the availability of the species or stock(s) for subsistence uses. NMFS
relies on two factors in determining if there will be an unmitigable
adverse impact on subsistence uses: First, the impact resulting from
the specified activity must be likely to reduce the availability of the
species to a level insufficient for a harvest to meet subsistence needs
by (1) causing the marine mammals to abandon or avoid hunting areas,
(2) directly displacing subsistence users, or (3) placing physical
barriers between the marine mammals and subsistence hunters. Second, it
must be an impact that cannot be sufficiently mitigated by other
measures to increase the availability of marine mammals to allow
subsistence needs to be met (50 CFR 216.103). This standard of
determining impact does not require the elimination of adverse impacts,
but it does require mitigation sufficient to meet subsistence
requirements. However, the MMPA also requires that, where applicable,
the measures will ensure the least practicable impact on the
availability of marine mammals for taking for subsistence uses. In
previous years, these conditions were met through the AEWC/oil
industry's C&AA which required seismic operations to move west of Cross
Island no later than September 1 or when whalers commenced the bowhead
hunting season, whichever was earlier. A signed C&AA allows NMFS to
conclude that there will not be an unmitigable adverse impact on the
subsistence needs of the Arctic Slope whalers this year due to seismic
activities.
Comment 7: LGL Limited notes that the mitigation section of the
Federal Register document does not mention that Western Geophysical
plans to participate in a C&AA with the whalers in order to avoid
interference with the autumn bowhead hunt. While the C&AA is mentioned
in the previous section (regarding impacts on subsistence uses),
Western Geophysical and LGL Ltd view the C&AA as one of the primary
mitigation measures, as it addresses the requirement to identify
measures to ensure the ``least practicable adverse impact on
...availability for subsistence uses.''
Response: Thank you for the comment.
Comment 8: Greenpeace contends that Western Geophysical's proposed
marine mammal monitoring program fails to adequately monitor the impact
of seismic operations on marine mammals.
Response: NMFS disagrees. Section 101(a)(5)(D)(ii)(II) of the MMPA
requires authorizations issued under this section to prescribe, where
applicable, requirements pertaining to the monitoring and reporting of
such taking by harassment, including requirements for independent peer
review of proposed monitoring plans or other research proposals where
the proposed activity may affect the availability of a species or stock
for taking for subsistence purposes.
Western Geophysical's proposed monitoring plan for 1999 and the
results from Western Geophysical's 1998 Beaufort Sea research were the
subject of a scientific peer-review workshop held in Seattle, WA, on
June 30 and July 1, 1999. As a result of that workshop, Western
Geophysical is amending its monitoring plan and will submit that plan
to NMFS for approval prior to commencement of the bowhead season.
Modifications to the original plan for monitoring during the bowhead
season (if seismic surveys are continuing at that time) include (1) an
extension of the aerial survey grid by an extra 15 km (8 nm) east and
west to approximately 65 km (35 nm) westward and 65 km eastward of the
seismic survey; this will address the issues (a) how far west of the
seismic area do bowhead whales remain farther offshore than usual if
bowheads are displaced offshore by seismic and (b) where the bowhead
whale deflection from the migration track due to seismic noise begins;
(2) an increase in the number of aerial survey track lines from 14 to
18; and (3) commencing the aerial surveys on September 1, rather than
September 4; and (4) additional autonomous seafloor acoustic recorders
offshore from the area of seismic operations.
Comment 9: The MMC recommends that the peer-review group
established to review the proposed monitoring and mitigation programs
be asked to consider the following questions: (1) Whether continuation
of the marine mammal observations in association with seismic surveys
in the nearshore waters of the Alaska Beaufort Sea beyond 1999 is
likely to produce significant new information on either the short- or
long-term effects of seismic surveys on marine mammals that occur in
the area, (2) whether the types of site-specific monitoring programs
conducted to date are sufficient to verify that seismic surveys and
related activities have negligible effects on the distributions, sizes,
and populations, and (3) if the answer to either issue is no, how
should the monitoring requirements be revised to better meet the intent
and provisions of the MMPA?
Response: NMFS believes that at a minimum, shipboard monitoring of
the safety zone must continue to implement mitigation measures to
protect marine mammals from potential serious injury. The Scientific
Peer Review Workshop participants concluded that the current research
and monitoring proposed here by Western Geophysical and by BPX for oil
development at Northstar (see 64 FR 9965, March 1, 1999), coupled with
existing projects to monitor bowhead population abundance (trends in
abundance) should provide information necessary to determine overall
cumulative impacts on bowhead whales. Existing projects include those
by the North Slope Borough (spring bowhead census), the MMS autumn
aerial survey, and the MMS-funded photo-identification of bowhead
whales being conducted as part of an on-going (1998-2000) bowhead
feeding study. Provided trends in bowhead abundance continue to be
positive, NMFS presumes industrial development on the North Slope is
not adversely affecting the bowhead population. Similar work is
underway for ringed seals.
Comment 10: Greenpeace believes that NMFS ignores cumulative
impacts from oil exploration and development in the Arctic on
subsistence communities, the bowhead whale, other marine mammals, and
the Arctic marine environment.
Response: Information on the cumulative impacts on the marine
environment from Beaufort Sea oil and gas leasing and development
activities, including seismic, in the area under discussion has been
addressed previously in several environmental impact statements (EIS)
prepared by the Minerals Management Service (MMS) (Final EISs for Lease
Sale 124 and 144 completed in 1990 and 1996). More recently, cumulative
impacts from oil exploration and development were extensively discussed
and evaluated in the U.S. Army Corps of Engineer's Final Environmental
Impact Statement (FEIS) on the Northstar Oil Development
[[Page 41389]]
Project (Corps, 1999). NMFS was a cooperating agency under the National
Environmental Policy Act (NEPA) in the preparation of that document.
Additional discussion on cumulative impacts from seismic activities in
conjunction with offshore oil and gas exploration and development can
be found in the EA prepared for this action (NMFS, 1999). NMFS notes
that because the Northstar Project construction has been delayed until
after the 1999 open water season, other than commercial barge traffic,
there are no identified activities that might cause a cumulative impact
on the whales, seals or subsistence needs of the North Slope this
season.
Comment 11: Noting that the activity for which an IHA
authorization is requested is part of an effort likely to be continued
in subsequent years and to eventually lead to drilling and other
activities associated with oil and gas exploration and production, the
MMC questions whether there is sufficient basis for concluding that
this year's activities, coupled with past and possible future
activities will not have a non-negligible cumulative effects on any of
the potentially affected marine mammal species or their availability to
Alaska Natives for subsistence uses. As a result, the MMC recommends
that NMFS, if it has not already done so, assess whether the monitoring
required as a condition of this and possible future IHAs will be
adequate to detect possible non-negligible cumulative effects and, if
not, what needs to be done to ensure that any such effects will be
detected before they reach significant levels and could be
irreversible.
Response: Please see response to comment 9.
Comment 12: Greenpeace noted that the results of Western
Geophysical's 1998 marine mammal monitoring program are not available
for review along with its 1999 IHA application. The results of the 1998
monitoring program should be available for public review prior to the
close of the public comment period.
Response: The preliminary results of the 1998 monitoring program
are contained in the 90-day report, which was issued in January 1999,
and in the IHA application. The draft final report for 1998 was due on
April 30, 1999. Because the draft final report was expanded to contain
an analysis of several previous years' data, the availability of this
report was delayed until late May, when it was reviewed by NMFS
scientists and participants at the peer review workshop. While
monitoring reports are available to the public for review, there is no
requirement for these documents to be made available for formal public
review and comment. Reviewers are encouraged to rely on the 90-day
report and reports from prior years if they wish to analyze the
previous years' data. As noted by Greenpeace in their letter, the 1996
and 1997 monitoring reports have been reviewed by them.
Endangered Species Act (ESA) Concerns
Comment 13: Without clarification, Greenpeace believes that
issuance of the IHA would violate the ESA.
Response: NMFS disagrees, noting that the issuance of an IHA to
Western Geophysical triggers section 7 of the ESA, as the issuance of
the IHA is a Federal action (please refer to the section titled ESA
later in this document). However, the major Federal agency for offshore
oil and gas lease activities is the MMS. Consultation under section 7
for lease sale 144 was concluded on November 16, 1995 with a finding
that the action was not likely to jeopardize the continued existence of
listed species under the jurisdiction of NMFS. This finding is
consistent with the conclusions and recommendations contained within
the Arctic Region Biological Opinion issued to MMS under section 7 of
the ESA by NMFS on November 23, 1988.
Reinitiation of formal consultation under section 7 is warranted
only when there is new scientific information that has the potential to
call into question the scientific and commercial data used in the
previous biological opinion. At this time, NMFS does not consider the
recent findings on impacts to listed marine species from the
disturbance from seismic surveys sufficient to reinitiate consultation.
NEPA Concerns
Comment 14: Greenpeace believes that the EA fails to adequately
analyze the full scope and cumulative impacts of current and proposed
offshore exploration and development activities in the Beaufort Sea.
Greenpeace maintains that the impacts from seismic operations cannot be
assessed separately from cumulative impacts from offshore exploratory
drilling, development and transportation activities that may follow or
are already occurring. This includes the impact of global warming on
the Arctic environment.
Response: Please see response to comment 10.
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 is limiting
the IHA authorization for a taking by harassment to no more than 12
airguns totaling 1,210 in3 during the 1999 open water
seismic survey. 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 will 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
measurements near the 1998 seismic array plus theoretical adjustments
for the smaller array size in 1999, 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 will 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., LGL Alaska Research
Associates, and Greeneridge Sciences (1999). This monitoring plan
[[Page 41390]]
has been peer-reviewed by NMFS, AEWC and industry scientists and others
at a workshop held in Seattle, WA on June 30 and July 1, 1999.
Suggested modifications to the monitoring plan as a result of the
workshop (most notably those summarized previously in the response to
comment 8) will need to be incorporated into the Plan prior to formal
acceptance by NMFS. During the 1999 open-water season, Western
Geophysical will conduct the following:
Vessel-based Visual Monitoring
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 darkness). In addition, Western Geophysical will experiment
with illumination of the safety zone with high-intensity lighting.
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 will conduct daily aerial surveys, weather permitting, from
September 1, 1999, for a period of 13-14 days, or, if seismic work ends
before September 13, until one day after seismic work ends. 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 will fly at 457 m (1500
ft) altitude over areas where whaling is occurring on that date 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 18 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 65 km (35 nm) east to 65 km
(35 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, the additional ``intensive'' grid survey will not be
conducted as in previous years.
Detailed information on the survey program can be found in Western
Geophysical (1999) and in LGL Ltd., LGL Alaska Research Associates, and
Greeneridge Sciences Inc. (1999), which are incorporated in this
document by citation.
Acoustical Measurements
The acoustic measurement program for 1999 is designed to continue
the acoustic work conducted in 1996 through 1998 (see LGL and
Greeneridge Sciences Inc., 1997, 1998, 1999). The acoustic measurement
program is planned to include (1) vessel-based acoustic measurements,
(2) OBC-based acoustic measurements, and, if seismic operations
continue into September, (3) use of air-dropped sonobuoys and (4)
bottom-mounted acoustical recorders.
(1) A vessel-based acoustical measurement program will be conducted
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 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 1 through 13, 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 two locations offshore of the seismic operation area, and
at one location about 40 km (25 mi) to the east, 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., LGL Alaska Research Associates, and
Greeneridge Sciences, 1999).
Estimates of Marine Mammal Take
Estimates of takes by harassment will be made through vessel and,
if seismic operations continue into September, aerial surveys. 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) 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
[[Page 41391]]
technical report will contain a description of the methods, results,
and interpretation of all monitoring tasks. This report will be subject
to review and comment by NMFS. Any recommendations made by NMFS will
need to be addressed in the final report prior to formal acceptance by
NMFS.
Consultation
Under section 7 of the ESA, NMFS has completed consultation on the
issuance of this authorization.
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 EIS 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
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. As a result, NMFS has again determined
that neither implementation of the authorization for the harassment of
small numbers of several species of marine mammals incidental to
conducting seismic surveys during the open water season in the U.S.
Beaufort Sea nor the alternatives to that action would significantly
affect the quality of the human environment. As a result, the
preparation of an EIS on this action is not required by section 102(2)
of NEPA or its implementing regulations.
Conclusions
Based on the evidence provided in the application, the EA, and this
document, and taking into consideration the comments submitted on the
EA, application, and proposed authorization notice, NMFS has determined
that there will be no more than a negligible impact on marine mammals
from the issuance of the harassment authorization to Western
Geophysical and that there will not be any unmitigable adverse impacts
to subsistence communities, provided the mitigation measures required
under the authorization are implemented. NMFS has 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
and avoidance reactions may be made by these species in response to 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, the number of potential harassment takings is
estimated to be small. In addition, no take by death and/or serious
injury 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 and required by the
authorization. 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 bowhead whales or the subsistence hunting of
bowhead whales prior to that date. After September 1, 1999, if seismic
activities continue beyond that date, aerial survey flights for bowhead
whale assessments will be initiated. Depending upon the date of
cessation of seismic activities (expected to be no later than September
10, 1999), NMFS estimates that fewer than 750 bowheads will be harassed
incidental to seismic-related activities.
Appropriate mitigation measures to avoid an unmitigable adverse
impact on the availability of bowhead whales for subsistence needs have
been the subject of consultation between Western Geophysical and
subsistence users. This C&AA, which consists of three main components:
(1) Communications, (2) conflict avoidance, and (3) dispute resolution,
has been concluded for the 1999 open-water seismic season.
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 seals and beluga 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.
Since NMFS is assured that the taking would not result in more than
the incidental harassment (as defined by the MMPA Amendments of 1994)
of small numbers of certain species of marine mammals, would have only
a negligible impact on these stocks, would not have an unmitigable
adverse impact on the availability of these stocks for subsistence
uses, and would result in the least practicable impact on the stocks,
NMFS has determined that the requirements of section 101(a)(5)(D) of
the MMPA have been met and the authorization can be issued.
Authorization
Accordingly, NMFS has issued an IHA to Western Geophysical for the
herein described seismic survey during the 1999 open water season
provided the mitigation, monitoring, and reporting requirements
described in this document and in the IHA are undertaken.
Dated: July 20, 1999.
Art Jeffers,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 99-19462 Filed 7-29-99; 8:45 am]
BILLING CODE 3510-22-F
