[Federal Register Volume 62, Number 77 (Tuesday, April 22, 1997)]
[Notices]
[Pages 19553-19557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-10254]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 040497A]
Small Takes of Marine Mammals Incidental to Specified Activities;
Offshore Seismic Activities in the Beaufort Sea
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of receipt of application and proposed authorization for
a small take exemption; request for comments.
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SUMMARY: NMFS has received a request from the BP Exploration (Alaska)
900 East Benson Boulevard, Anchorage, AK 99519 (BPXA) for a renewal of
an authorization to take small numbers of marine mammals by harassment
incidental to conducting seismic surveys in and near the Northstar
Unit, 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 BPXA 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 1997.
DATES: Comments and information must be received no later than May 22,
1997.
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, an environmental assessment (EA), an informal section
7 consultation, the 90-day Report, 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 below.
FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, Office of
Protected Resources, NMFS, (301) 713-2055, Brad Smith, Western Alaska
Field Office, NMFS, (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), will not have an
unmitigable adverse impact on the availability of the species or
stock(s) for subsistence uses, and 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 March 5, 1997, NMFS received an application from BPXA requesting
a 1-year renewal of their authorization for
[[Page 19554]]
the harassment of small numbers of several species of marine mammals
incidental to conducting seismic surveys during the open water season
within and near the Northstar Unit, in the Beaufort Sea between
145 deg. 30'W and 150 deg. 30'W, in U.S. waters. Weather permitting,
the survey is expected to take place between approximately July 1 and
October 20, 1997. A detailed description of the work planned is
contained in the application (BPXA 1997) 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 (BPXA 1996b) or in other documents (Minerals Management
Service (MMS) 1992, 1996) 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 others, can be found in several other documents
(BPXA 1996b, 1997, Lentfer 1988, MMS 1992, NMFS 1990 and 1996, Small
and DeMaster 1995). 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. Vessels and aircraft will provide a secondary source of
noise.
Deep seismic surveys are used to obtain data about formations
several thousands of feet deep. The physical presence of vessels and
aircraft could also lead to non-acoustic effects involving visual or
other cues. The proposed seismic operation is an ocean bottom cable
(OBC) survey. OBC surveys involve dropping a cable from a ship to the
ocean bottom. Sensors (hydrophones) are attached to the cable. 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 downwards toward the seabed. After sufficient energy has
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, including numbers of vessels planned for this
survey, please refer to the application (BPXA 1997).
Depending upon ambient conditions and the sensitivity of the
receptor, underwater sounds produced by open water seismic operations
may be detectable some 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 masking a signal of
comparable frequency (BPXA 1997). 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 visual cues.
Seismic pulses are known to cause bowhead whales to behaviorally
respond within a distance of several kilometers (km) (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 sec every 6-12 sec) 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 (BPXA
1997).
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 below) 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 (BPXA 1997). The
levels, frequencies, and types of noise that will elicit a response
vary between and within species, individuals, locations and season.
Behavioral changes may be subtle alterations in surface-respiration-
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 (BPXA 1997).
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 4.5 miles (mi) (7.5 km) 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 1996).
Within a 3.7-60 mi (6-99 km) 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 (BPX 1996).
Preliminary 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 precluded
meaningful interpretation (BPXA 1997).
Gray Whales
The reactions of gray whales to seismic pulses is 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 about 50 percent showed avoidance when the
average received pulse level was 170 dB (re 1 Pa @ 1 m). Less
consistent results were indicated at levels of 140-160 dB.
[[Page 19555]]
Belukha
The belukha is the only species of toothed whale (Odontoceti)
expected to be encountered in the Beaufort Sea. Because its 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 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 large distances (Richardson
1991, 1995).
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 needed to be 80-100 dB over its
threshold in order to cause annoyance and 130 dB for injury (pain), as
is the current thought based upon human studies (ARPA and NMFS 1995),
then 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, marine mammals
would 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/WDFW 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 Western Beaufort Sea waters, pinnipeds have previously been
exposed to seismic noise, and may not react to it, after initial
exposure.
Numbers of Marine Mammals Expected To Be Taken
Based upon calculations provided in their application, BPXA
estimates that the following numbers of marine mammals may be subject
to Level B harassment, as defined in 50 CFR 216.3:
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Harassment takes in 1997
Species Population size ------------------------------------------------
Possible Probable
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Bowhead.............................. 8,000................... 400 200
Gray whale........................... 23,000.................. <10 0="" belukha..............................="" 41,610..................="" 250="" 150="" ringed="" seal..........................="" 1-1.5="" million...........="" 400=""><400 spotted="" seal.........................="">200,000................ 10 5
Bearded seal......................... >300,000................ 50 30
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Effects of Seismic Noise and Other Activities on Subsistence Needs
The disturbance and potential displacement of marine mammals by
sounds from seismic activities is the principle concern 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 (BPXA 1997). In particular, if migrating bowhead whales are
displaced farther offshore by elevated noise levels, this could make
harvest of these whales more difficult and dangerous for hunters. The
harvest could also be affected if bowheads are more skittish when
exposed to seismic noise (BPXA 1997).
Nuiqsut is the community closest to the area of the proposed
activity, and only harvests bowhead whales during the fall whaling
season. Nuiqsut whalers typically take zero to three whales each season
(four in 1995; two in 1996), with a trend toward larger harvests in the
most recent years (BPXA 1997). Nuiqsut whalers concentrate their
efforts on areas north and east of Cross Island, generally in water
depths greater than 65 ft (20 m). Cross Island is the principle field
camp location for Nuiqsut whalers and 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 BPXA to
provide NMFS with a Plan of Cooperation with North Slope residents
(also called the Communications and Avoidance Agreement) to avoid any
unmitigable adverse impact on subsistence needs.
Whalers from the village of Kaktovik search for whales east, north
and west of the village. Kaktovik is located 45 mi (72 km) east of the
easternmost end of the planned seismic exploration area. The
westernmost reported harvest location was about 13 mi (21 km) west of
Kaktovik, near 70 deg.10' N, 144 deg.W. That site is about 32 mi (51
km) east of the closest part of the primary seismic exploration area
(BPXA 1997). However, it should be noted that the eastern portion of
the geographic area noted by BPXA for the authorization extends
considerably closer to this harvest area.
Whalers from the village of Barrow search for bowhead whales much
further from the planned seismic area, >125 mi (>200 km) west (BPXA
1997).
The location of the proposed seismic activity is south of the main
westward migration route of bowhead whales. BPXA (1997) believes that
although
[[Page 19556]]
whales may be able to hear the sounds emitted by the seismic array out
to a distance of 30 mi (50 km) or more, it is unlikely that changes in
migration route will occur at distances of >15 miles (>25 km).
It is recognized that it is difficult to determine the maximum
distance at which reactions occur (Moore and Clark 1992), although
whalers believe that some migrating bowheads are deflected by seismic
operations at distances greater than those documented by scientific
studies done to date. As a result, BPXA is developing a Communications
and Avoidance Agreement with the whalers (see BPXA 1997) to reduce any
potential interference with the hunt. Also, it is believed that the
monitoring plan proposed by BPXA (LGL and Greeneridge 1997) will
provide information that will help resolve uncertainties about the
effects of seismic exploration on the accessibility of bowheads to
hunters.
In addition, while seismic exploration in the Northstar Unit 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 (BPXA 1997). In
summer, boat crews hunt ringed, spotted and bearded seals (BPXA 1997).
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 (BPXA 1997). 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 (BPXA
1997).
Mitigation
BPXA proposes to continue the mitigation program carried out in
1996. BPXA 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, BPXA will power down the seismic
source if pinnipeds are sighted:
(a) within 260 m (853 ft) of an array of >720 in3 and
1,320 in3 at 2.5 m (8.3 ft) depth;
(b) within 130 m (426 ft) of that array operating at >2.5 m (8.3
ft) depth;
(c) within 130 m (426 ft) of an array of >120 in3 and
720 in3 operating at 2.5 m (8.3 ft)
depth;
(d) within 60 m (197 ft) of that array operating at <2.5 m="" (8.3="" ft)="" depth;="" and="" (e)="" within="" 60="" m="" (197="" ft)="" of="" a="" single="" airgun="" or="" an="" array="" of="">120 in3.
BPXA will power down the seismic source if bowhead, gray, or
belukha whales are sighted:
(a) within either 1020 m (3346 ft) of an array >720 in3
and 1,320 in3 operating at 2.5m (8.3
ft) depth; or
(b) within 640 m (2100 ft) of that array operating at <2.5 m="" (8.3="" ft)="" depth="" or="" of="" any="" smaller="" airgun="" source="" operating="" at="" any="" depth="" (bpxa="" 1997).="" in="" addition,="" bpxa="" 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="" their="" application="" bpxa="" has="" provided="" a="" monitoring="" plan="" for="" assessing="" impacts="" to="" marine="" mammals="" from="" seismic="" surveys="" in="" the="" beaufort="" sea="" (lgl="" and="" greeneridge="" 1997).="" 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,="" bpxa="" plans="" to="" conduct="" the="" following.="" vessel-based="" visual="" monitoring="" a="" minimum="" of="" two="" biologist-observers="" aboard="" each="" 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="" above),="" the="" geophysical="" crew="" leader="" will="" be="" notified="" so="" that="" shutdown="" procedures="" can="" be="" implemented="" immediately.="" aerial="" surveys="" from="" september="" 1,="" 1997,="" until="" 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="" for="" assessing="" 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="" 1,000="" ft="" (300="" m)="" above="" sea="" level.="" bpxa="" proposes="" to="" avoid="" overflights="" of="" the="" cross="" island="" area="" where="" whalers="" from="" nuiqsut="" are="" based="" during="" their="" fall="" whale="" hunt.="" the="" daily="" aerial="" surveys="" are="" proposed="" to="" cover="" two="" grids:="" a="" grid="" of="" 12="" north-south="" lines="" spaced="" 5="" mi="" (8="" km)="" apart="" and="" extending="" from="" about="" 12.5="" mi="" (20="" km)="" west="" of="" the="" western="" side="" of="" the="" then-current="" seismic="" exploration="" area="" to="" 30="" mi="" (50="" km)="" east="" of="" its="" eastern="" edge,="" and="" from="" the="" barrier="" islands="" north="" to="" approximately="" the="" 100="" m="" (328="" ft)="" depth="" contour;="" a="" grid="" of="" 4="" survey="" lines="" within="" the="" above="" region,="" also="" spaced="" 5="" mi="" (8="" km)="" apart="" and="" mid-way="" between="" the="" longer="" lines,="" to="" provide="" more="" intensive="" coverage="" of="" the="" area="" of="" the="" seismic="" operations="" and="" immediate="" surrounding="" waters.="" acoustical="" measurements="" the="" acoustic="" measurement="" program="" proposed="" for="" 1997="" is="" designed="" to="" be="" a="" sequel="" to="" the="" program="" conducted="" at="" northstar="" in="" 1996="" (see="" bpxa="" 1996a="" and="" 1997,="" lgl="" and="" greeneridge="" 1996b="" and="" 1997="" for="" a="" description="" of="" the="" work="" proposed).="" the="" acoustic="" measurement="" program="" is="" planned="" to="" include="" (1)="" retrieval="" of="" bottom="" recorders="" deployed="" in="" 1996="" and="" analysis="" of="" usable="" data="" contained="" in="" those="" recorders,="" (2)="" boat-based="" acoustic="" measurements,="" and="" (3)="" obc-based="" acoustic="" measurements.="" two="" differences="" between="" the="" 1996="" and="" 1997="" programs="" are="" that="" bpxa="" does="" not="" plan="" to="" deploy="" sonobuoys="" during="" the="" 1997="" aerial="" surveys,="" and="" will="" not="" redeploy="" the="" bottom-mounted="" recorders="" (5="" of="" the="" 10="" units="" remain="" non-functional="" on="" the="" sea="" bottom).="" the="" boat-based="" acoustical="" measurement="" program="" is="" proposed="" for="" a="" 7-="" day="" period="" in="" mid-to="" late-august="" 1996.="" 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(s)="" of="" airgun="" array(s)="" to="" be="" used="" in="" 1977="" as="" a="" function="" of="" distance="" and="" aspect="" relative="" to="" the="" seismic="" source="" vessel(s)="" and="" relative="" to="" water="" depth.="" (b)="" to="" measure="" the="" levels="" and="" frequency="" composition="" of="" the="" vessel="" sounds="" emitted="" by="" vessels="" used="" regularly="" during="" the="" 1977="" program,="" excluding="" vessels="" whose="" sounds="" were="" characterized="" adequately="" in="" 1996.="" (c)="" to="" obtain="" additional="" site-specific="" ambient="" noise="" data,="" which="" determine="" signal-to-noise="" ratios="" for="" seismic="" and="" [[page="" 19557]]="" other="" acoustic="" signals="" at="" various="" ranges="" from="" their="" sources.="" new="" to="" the="" acoustic="" measurement="" program="" for="" 1997="" is="" a="" plan="" to="" test="" the="" feasibility="" to="" use="" the="" hydrophones="" in="" the="" obc="" to="" measure="" received="" levels="" and="" characteristics="" of="" airgun="" pulses="" over="" a="" large="" area="" (about="" 3.3x5.9="" km)="" simultaneously.="" if="" practical,="" this="" would="" provide="" more="" comprehensive="" data="" while="" at="" the="" same="" time="" reducing="" the="" need="" for="" labor-="" intensive="" boat-based="" acoustic="" measurements.="" estimates="" of="" marine="" mammal="" take="" estimates="" of="" takes="" by="" harassment="" will="" be="" made="" through="" vessel="" and="" aerial="" surveys.="" preliminarily,="" bpxa="" 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)="" above="" when="" no="" monitoring="" observations="" were="" possible;="" and="" (d)="" bowheads="" displaced="" seaward="" from="" the="" main="" migration="" corridor.="" reporting="" bpxa="" will="" provide="" an="" initial="" report="" on="" 1997="" 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="" bpxa="" within="" 20="" working="" days="" of="" receipt="" of="" the="" document="" from="" the="" contractor,="" but="" no="" later="" than="" april="" 30,="" 1998.="" 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,="" nmfs="" completed="" an="" informal="" consultation="" on="" the="" issuance="" of="" an="" incidental="" harassment="" authorization="" for="" this="" activity="" on="" july="" 15,="" 1996.="" a="" copy="" of="" that="" document="" is="" available="" upon="" request="" (see="" addresses).="" national="" environmental="" policy="" act="" (nepa)="" in="" conjunction="" with="" the="" 1996="" notice="" of="" proposed="" authorization="" (61="" fr="" 26501,="" may="" 28,="" 1996),="" 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="" to="" bpxa="" for="" the="" harassment="" of="" small="" numbers="" of="" several="" species="" of="" marine="" mammals="" incidental="" to="" conducting="" seismic="" surveys="" during="" the="" open="" water="" season="" in="" the="" northstar="" unit="" and="" nearby="" waters="" 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).="" conclusions="" nmfs="" has="" preliminarily="" determined="" that="" the="" short-term="" impact="" of="" conducting="" seismic="" surveys="" in="" the="" northstar="" unit="" of="" the="" beaufort="" sea="" will="" result,="" at="" worst,="" in="" a="" temporary="" modification="" in="" behavior="" by="" certain="" species="" of="" cetaceans.="" while="" behavioral="" modifications="" may="" be="" made="" by="" these="" species="" of="" cetaceans="" 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="" incorporation="" of="" the="" mitigation="" measures="" mentioned="" above.="" 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,="" 1997,="" bpxa="" will="" initiate="" aerial="" survey="" flights="" for="" bowhead="" whale="" assessments.="" 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="" bpxa="" and="" subsistence="" users.="" also,="" while="" summer="" seismic="" exploration="" in="" the="" northstar="" unit="" 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="" (west="" and="" inshore="" of="" northstar),="" and="" (3)="" the="" zone="" of="" influence="" by="" seismic="" sources="" on="" belukha="" and="" seals="" is="" fairly="" small,="" nmfs="" believes="" the="" northstar="" 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="" 1997="" beaufort="" sea="" open="" water="" season="" for="" a="" seismic="" survey="" in="" and="" near="" the="" northstar="" unit="" 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;="" will="" have="" a="" negligible="" impact="" on="" these="" marine="" mammal="" stocks;="" and="" will="" not="" have="" an="" unmitigable="" adverse="" impact="" on="" the="" availability="" of="" these="" stocks="" for="" subsistence="" uses.="" information="" solicited="" nmfs="" requests="" interested="" persons="" to="" submit="" comments,="" information,="" and="" suggestions="" concerning="" this="" request="" (see="" addresses).="" dated:="" april="" 16,="" 1997.="" hilda="" diaz-soltero,="" acting="" director,="" office="" of="" protected="" resources,="" national="" marine="" fisheries="" service.="" [fr="" doc.="" 97-10254="" filed="" 4-21-97;="" 8:45="" am]="" billing="" code="" 3510-22-p="">