[Federal Register: March 25, 2003 (Volume 68, Number 57)]
[Notices]
[Page 14401-14408]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25mr03-44]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 030403B]
Small Takes of Marine Mammals Incidental to Specified Activities;
Taking of Ringed and Bearded Seals Incidental to On-ice Seismic
Activities
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) has been issued to ConocoPhillips Alaska
Inc. (CPA) to take small numbers of ringed and bearded seals, by
harassment, incidental to conducting on-ice seismic operations in the
Beaufort Sea during oil and gas exploration activities.
DATES: This authorization is effective from March 19, 2003, through
July 1, 2003.
ADDRESSES: A copy of the application and/or a list of references used
in this document may be obtained by writing to the Chief, Marine Mammal
Conservation Division, Office of Protected Resources, National Marine
Fisheries Service, 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, Office of
Protected Resources, NMFS, (301) 713-2055, ext 128, or Bradley Smith,
Alaska Region (907) 271-5006.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional taking of 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, notice of a proposed authorization is
provided to the public for review.
Permission may be granted if NMFS finds that the taking will have
no more than a negligible impact on the species or stock(s) and will
not have an unmitigable adverse impact on the availability of the
species or stock(s) for subsistence uses and that the permissible
methods of taking and requirements pertaining to the monitoring and
reporting of such taking are set forth.
On April 10, 1996 (61 FR 15884), NMFS published an interim rule
establishing, among other things, procedures for issuing IHAs under
section 101(a)(5)(D) of the MMPA for activities in Arctic waters. For
additional information on the procedures to be followed for this
authorization, please refer either to that document or to 50 CFR
216.107.
Description of the Activity
Background
Deep seismic surveys use the ``reflection'' method of data
acquisition. Reflection seismic exploration is the process of gathering
information about the subsurface of the earth by measuring acoustic
(sound or seismic) waves, which are generated on or near the surface.
Acoustic waves reflect at boundaries in the earth that are
characterized by acoustic impedance contrasts. The acoustic impedance
of a rock layer is its density multiplied by its acoustic velocity.
Geologists and geophysicists commonly attribute different acoustic
impedances to different rock characteristics. Seismic exploration uses
a controlled energy source to generate acoustic waves that travel
through the earth (including sea ice and water, as well as subsea
geologic formations), and then uses ground sensors to record the
reflected energy transmitted back to the surface. Energy that is
directed into the ground takes on numerous forms. When acoustic energy
is generated, compression (p) and shear (s) waves form and travel in
and on the earth. The compression and shear waves are affected by the
geological formations
[[Page 14402]]
of the earth as they travel in it and may be reflected, refracted,
diffracted or transmitted when they reach a boundary represented by an
acoustic impedance contrast.
The basic components of a seismic survey include an energy source
(either acoustic or vibratory), which generates a seismic signal;
hydrophones or geophones, which receive the reflected signal; and
electronic equipment to amplify and record the signal. The number and
placement of sensors, the energy sources, the spacing and placement of
energy input locations, and the specific techniques of recording
reflected energy are broadly grouped as ``parameters'' of a given
exploration program.
In modern reflection seismology, many sensors are used to record
each energy input event. The number of sensors in use for each event
varies widely according to the type of survey being conducted and the
recording equipment available. Common numbers of groups of sensors are
240, 480, and 1040, and some new recording instruments may use as many
as 4000 groups of sensors at the same time. The sensors are normally
placed in one or more long lines at specified intervals. In North
America the common group placement intervals are multiples of 55 ft (17
m), 110 ft (33.5 m) and 220 ft (67 m).
Vibroseis
Vibroseis seismic operations use large trucks with vibrators that
systematically put variable frequency energy into the earth. At least
1.2 m (4 ft) of sea ice is required to support heavy vehicles used to
transport equipment offshore for exploration activities. These ice
conditions generally exist from 1 January until 31 May in the Beaufort
Sea. The exploration techniques are most commonly used on landfast ice,
but they can be used in areas of stable offshore ice. Several vehicles
are normally associated with a typical vibroseis operation. One or two
vehicles with survey crews move ahead of the operation and mark the
energy input points. Crews with rubber-tire or rubber-track vehicles
often require trail clearance with bulldozers for adequate access to
and within the site. Crews with rubber-tracked vehicles are typically
limited by heavy snow cover, and may require trail clearance
beforehand.
A typical wintertime exploration seismic crew consists of 40-110
personnel. Roughly 75 percent of the personnel routinely work on the
active seismic crew, with approximately 50 percent of those working in
vehicles and the remainder outside laying and retrieving geophones and
cable. A camp unit is usually associated with a seismic survey project
and will consist of 4-5 sleeper/office trailers, a kitchen/diner
trailer, two shop/generator trailers, fuel sleighs and a small survival
trailer (BP, 1997). Camp trailers are usually mounted on wide-pad
sleighs. It is common to survey and plow ``communication'' roads on sea
ice for vehicles to travel to and from the camp.
With the vibroseis technique, activity on the surveyed seismic line
begins with the placement of sensors. All sensors are connected to the
recording vehicle by multi-pair cable sections. The vibrators move to
the beginning of the line, and recording begins. The vibrators move
along a source line, which will be at some angle to a sensor line. The
vibrators begin vibrating in synchrony via a simultaneous radio signal
to all vehicles.
In a typical survey, each vibrator will vibrate four times at each
location. The entire formation of vibrators subsequently moves forward
to the next energy input point (e.g., 67 m (220 ft) in most
applications) and repeat the process. In a typical 16- to 18-hour day,
4 to 10 linear mi (6 to 16 km) in 2D-seismic operations and 15 to 40
linear mi (24 to 64 km) in a 3D-seismic operation are conducted. A
detailed description of the work proposed for 2003 is contained in this
document and in the application which is available upon request (see
ADDRESSES).
Summary of the Request
On October 3, 2002, CPA submitted an application to NMFS for an IHA
for the taking of ringed seals (Phoca hispida) and bearded seals
(Erignathus barbatus) for a period of 5 months beginning January 1
(upon the expiration of the existing regulations covering the Alaskan
North Slope on 31 December 2002 (63 FR 5277, February 2, 1998)) and
ending on about May 31, 2003. On-ice seismic operations are ordinarily
confined to this 5-month period since this is the period when ice is
sufficiently thick (4 - 5 ft; 1.2 - 1.5 m) to safely support the
equipment.
The geographic region of activity in 2003 encompasses an 846-square
mile (2,190 km\2\) area extending from approximately Cape Halkett on
the west to Oliktok Point on the east and to approximately 4-20 nm (7.4
- 37 km) offshore the coast. Water depths in most ( 60
percent) of the area are less than 10 ft (3 m), but drop to 30 ft (9 m)
along the northern fringe of the region of activity. Few seals inhabit
water less than 10 ft (3 m) during winter, since water typically
freezes to or near the bottom at this depth or what water is available
supports few food resources (Miller et al., 1998 and Link et al.,
1999).
Comments and Responses
A notice of receipt of the application and proposed authorization
was published on December 31, 2002 (67 FR 79565), and a 30-day public
comment period was provided on the application and proposed
authorization. Comments were received from the Marine Mammal Commission
(MMC) and the Alaska Eskimo Whaling Commission (AEWC).
Comment 1: The AEWC disagrees with NMFS' statement in its notice of
receipt and proposed authorization that Nuiqsut hunters are most likely
to take ringed seals during the open water season. The AEWC notes that
this conclusion is based on two studies and harvest data collected in
one year, 1992. They state, ``While many events, including the
availability of seasonal construction work, may affect subsistence
patterns from year to year, NMFS certainly is aware of the fact that
subsistence hunting is an opportunistic activity. Ignoring this fact
for even a seemingly low impact activity sets a dangerous precedent for
subsistence hunters.''
Response: NMFS is required to incorporate the best scientific and
commercial information (including traditional knowledge) currently
available when making a determination that an activity will not have
more than a negligible impact on affected marine mammal species nor
have an unmitigable adverse impact on subsistence needs for marine
mammals. In 50 CFR 216.103, NMFS provides its definition for what is an
``unmitigable adverse impact.''
The study cited by NMFS in the Federal Register and by the
commenter was a 1996 analysis conducted by the North Slope Borough
(NSB), presumably based on 1992 harvest data. While this is only a
single year of harvest data, that information is consistent with
previous statements made by NMFS as several small take applicants for
wintertime activities in the Beaufort Sea have provided subsistence
harvest data used by NMFS in previous authorizations (NMFS, 1998; 62 FR
5564 (October 27, 1997), and this document). NMFS would therefore
appreciate any updated information for use in future small take
authorizations.
Comment 2: The AEWC recommends a reasonable mitigation measure. As
NMFS notes, the Nuiqsut hunters take ringed seals primarily in the
Colville River Delta. As more daylight becomes available during the
spring, subsistence
[[Page 14403]]
hunting of all types tends to increase. Therefore, a reasonable
compromise between CPA's seismic work and ringed seal hunting by
Nuiqsut hunters would be for CPA to begin their work in the eastern
portion of Harrison Bay and work westward. This will reduce the
probability that ringed seal hunters who have an opportunity to hunt
during the spring will encounter seismic operations that might
interfere with their seal hunting.
Response: NMFS has included this recommendation in the subject IHA
and will suggest such a strategy for future vibroseis activities in
Harrison Bay. However, such a recommendation is contingent upon
favorable ice conditions permitting an east-to-west mapping strategy.
As a result, NMFS has made this a recommendation, not a requirement in
the IHA. NMFS notes however, that the IHA requires CPA to communicate
with the village of Nuiqsut as to location and timing of activities.
Comment 3: The AEWC also recommends a refinement of the previous
mitigation measure might also reduce the chance that this seismic work
could affect migrating bowhead whales. The AEWC recommends that CPA be
required to first complete all work in waters where the depth is
greater than three m (9.8 ft) (moving east to west), then go on to
their work in waters where the depth is less than 3 m (9.8 ft).
Response: In general, NMFS believes that ice conditions would
preclude working from deeper water landward early in the season.
Vibroseis activities require a minimum ice depth of 3 to 4 ft (0.9 to
1.2 m) to support the equipment, therefore, standard operations are to
move from shore onto grounded ice first, then moving offshore as
conditions permit. However, because ringed seals are not normally found
in water depths less than 3 m (0.9 ft), and because after about March
20, neonatal ringed seal pups may be exposed to vibroseis sounds, this
recommendation has merit to mitigate impacts to adult ringed seals and
pups. As a result, NMFS has added this recommendation to the IHA,
recognizing that such a strategy would depend upon ice conditions and
seismic survey objectives.
The effective source level of vibroseis sounds for horizontal
propagation in shallow under ice waters, while uncertain, may at times
be as high as 212 dB re (Malme et al., 1989). Received levels would be
expected to diminish below 180 dB within 100 m (328 ft)(BP, 1997).
Holliday et al. (1984) as cited in Richardson et al. (1995) estimated
that in-water vibroseis sounds would diminish to the ambient noise
level (about 70 dB) at distances of 3.5 to 5 km (2.2 to 3.1 mi). Since
the spring leads tend north and east of Pt. Barrow, NMFS believes that
Harrison Bay would be well south of any such lead, even during
unusually open conditions. As a result, NMFS does not believe that
vibroseis sounds would reach the offshore leads and influence bowhead
whale behavior.
Comment 4: The AEWC recommends that CPA should be required to work
out a Conflict Avoidance Agreement (CAA) with the AEWC to ensure that
there is no impact to the bowhead migration. The issues that the AEWC
will focus on are timing and location of the late-season activities.
Response: Based on the response to comment 3, NMFS does not believe
that there will be any impact to bowhead whales because of the distance
between vibroseis operations and the offshore leads used by bowheads
during their eastward migration. Generally, CAAs are limited to
activities that have the potential to disturb bowheads just prior to,
and during the bowhead subsistence hunt and therefore, would be subject
for discussion and resolution during the CAA negotiations. Therefore,
because the CAA is intended to reduce impacts to the subsistence
harvest of bowhead whales, if bowhead whales are unlikely to be taken,
a CAA is not warranted. Finally, NMFS is unaware that there is a spring
harvest of bowhead whales in the offshore waters of Harrison Bay that
would warrant NMFS encouraging CPA to seek resolution of impacts on the
bowhead harvest. It should be noted that a CAA is a formal agreement
between the activity's participants and the AEWC. NMFS does not play a
role in its development or implementation.
Comment 5: The MMC believes that the preliminary determinations
made by NMFS seem reasonable provided that, prior to commencing on-ice
seismic surveys after mid-March, a survey using experienced field
personnel and trained dogs be conducted to identify potential seal
structures along the planned on-ice seismic transmission routes. As
noted in previous MMC correspondence, the MMC believes that the use of
trained dogs is the only reliable method for locating seal lairs and
other structures.
Response: As noted in CPA's application, and confirmed by CPA
during the October 30, 2002, CPA will utilize trained dogs for any
offshore vibroseis work that takes place after March 20, 2003, in
waters [gteqt] 3 m (9.8 ft).
Comment 6: The MMC believes that in the event that trained dogs are
not available, NMFS should not accept monitoring by humans as an
alternative until it has been demonstrated that such monitoring is as
effective as that carried out using dogs.
Response: NMFS does not agree with the recommendation of the MMC.
There are only one or two individuals available in Alaska that have
dogs trained to locate ringed seal lairs. These individuals may also
have work, such as conducting scientific research, that would make them
unavailable for monitoring at the precise time they might be needed.
NMFS believes that, if necessary, trained dogs should be available
first to activities that have the greatest potential for injury or
mortality to ringed seals and/or their young, such as construction of
ice roads.
Comment 7: The MMC also notes that CPA is planning to conduct
surveys to a distance of 150 m (492 ft) on each side of all transit
routes and recommends that such surveys be made a requirement of the
IHA.
Response: This mitigation measure was proposed by CPA and has been
incorporated by NMFS into CPA's IHA.
Comment 8: The MMC recommends that should a mortality or serious
injury of a seal occur, the authorization specify that operations be
suspended while NMFS determines whether steps can be taken to avoid
further injuries or mortalities or whether an incidental take
authorization under section 101(a)(5)(A) of the MMPA to cover such
taking is needed.
Response: Since the taking by serious injury or mortality of ringed
seals, or any taking of any other species of marine mammals is
prohibited under this IHA, any incidents must be reported to the
Regional Administrator, NMFS, or his designee, immediately. As stated
in the IHA, takings in violation of the IHA may result in the
modification, suspension or revocation of the IHA, depending upon the
initial determination of the Regional Administrator.
Comment 9: Even though the effects of the activities proposed by
the applicant, by themselves, are likely to be negligible, the MMC is
concerned that the cumulative impacts of such activities in combination
with similar activities being carried out elsewhere in the Beaufort Sea
may, at some point, have more than negligible impacts on marine mammal
populations. As such, the MMC recommends that the monitoring programs
for such activities be expanded to enable NMFS to assess whether and,
if so, to what extent long-term, cumulative effects may be occurring.
Such information is essential for ensuring that subtle changes
occurring over short periods of time (i.e., seasonally or annually) do
not have
[[Page 14404]]
more than negligible impacts over longer time periods.
Response: Under section 101(a)(5)(D) of the MMPA, an applicant is
responsible for conducting a monitoring program to provide information
on whether its activity is having more than a negligible impact on
affected species and stocks of marine mammals. There is no requirement
for conducting monitoring to determine whether all activities in the
Beaufort Sea might some day have a significant cumulative impact on
marine mammals, a term recognized under the National Environmental
Policy Act (NEPA).
As required by regulations and MMPA, on October 30, 2002, CPA's
proposed monitoring plan was peer-reviewed and accepted by the
participants at the peer-review workshop held in Anchorage, AK (Angliss
(ed), 2002). This workshop was the fourth in recent years to discuss
impacts of on-ice activities on marine mammals. At this meeting, NMFS
recommended that the industry set up a research fund through an
independent organization, such as the National Fish and Wildlife
Federation or NOAA Sea Grant. A competitive process for directed funds
might encourage marine mammal scientists to develop creative ways to
get a better handle on site-specific and cumulative impacts on seals
resulting from winter-time activities. The industry suggested that this
should be a cooperative undertaking between government and industry.
Participants indicated that they would continue to discuss this concept
at future meetings.
It should be recognized that research and monitoring of Beaufort
Sea marine mammals are also conducted by government agencies, or
through government agency funding. This includes, for example, MMS'
aerial bowhead whale surveys, an annual population assessment survey
for bowhead whales, a study on contaminant levels in bowhead whale
tissue, and a bowhead whale health assessment study. These latter three
studies are funded by or through NMFS. Information on these projects
has been provided in the past to the MMC by NMFS. Based on this multi-
faceted monitoring program, NMFS has determined that the monitoring
programs for both open-water and wintertime are adequate to identify
impacts on marine mammals, both singly from the project and
cumulatively throughout the industry.
Comment 10: The MMC believes that important types of long-term
information should be gathered as part of the required monitoring plan
including data on potential changes in density and abundance of
potentially affected marine mammals, reproductive rates, foraging
patterns, distribution, and contamination levels where oil and gas
exploration, development, and production occurs.
Response: See response to comment 7. NMFS would welcome the
participation of the MMC and/or its scientific advisors at its twice-
annual peer-review meetings held to discuss monitoring proposed to be
undertaken by Arctic-activity applicants for authorizations under
section 101(a)(5) of the MMPA. In addition, NMFS would welcome
suggestions from the MMC on future methodology to economically assess
the suggested parameters for ice-seals during the Arctic winter.
Description of Habitat and Marine Mammals Affected by the Activity
A detailed description of the Beaufort Sea ecosystem can be found
in several documents (Corps of Engineers, 1999; NMFS, 1999; Minerals
Management Service (MMS), 1992, 1996, 2001) and is not repeated here.
Marine Mammals
The Beaufort/Chukchi Seas support a diverse assemblage of marine
mammals, including bowhead whales (Balaena mysticetus), gray whales
(Eschrichtius robustus), beluga (Delphinapterus leucas), ringed seals,
spotted seals (Phoca largha) and bearded seals. Descriptions of the
biology and distribution of these species and of others can be found in
NMFS (1998, 1999), Western Geophysical (2000) and several other
documents (Corps of Engineers, 1999; Lentfer, 1988; MMS, 1992, 1996;
Angliss et al. (2001)). Angliss et al. (2001) is available online
at:http://www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/
sars.html#Stock
Assessment Reports.
Ringed and, to a lesser degree, bearded seals could be affected by
on-ice seismic activities. These species as well as other marine mammal
species in the Beaufort Sea appear to have stable to increasing
populations, which is a condition indicative of a healthy ecosystem.
Polar bears, which prey on these species, are believed to be stable or
increasing in numbers in the Beaufort Sea (U.S. Fish and Wildlife
Service (USFWS), 2000 a, b). Similarly, the most recent estimate of
bowhead whales shows the population has steadily increased annually at
a growth rate of 3.2-3.3 percent to 9,860 (7,700-12,600) animals
(International Whaling Commission, 2002). These increases are occurring
in concert with subsistence harvest of these species including a 5-year
harvest quota of 255 bowheads. The status of these marine mammal
populations reflects the high quality of the habitat, which supports
abundant and diverse prey populations.
Ringed seals are year-round residents in the Beaufort Sea. They are
the most abundant and widely distributed species of marine mammal in
the Beaufort Sea (Frost et al., 1988). The world-wide population is
estimated at 6 to 7 million (Stirling and Calvert, 1979). The Alaska
stock of the Bering-Chukchi-Beaufort Sea area is roughly estimated at
between 1 to 1.5 (Frost, 1985) to 3.3 to 3.6 million seals (Frost et
al., 1988). Although there are no recent population estimates in the
Beaufort Sea, Bengston et al. (2000) estimated ringed seal abundance
from Barrow south to Shismaref in a portion of the Chukchi Sea to be
245,048 animals from aerial surveys flown in 1999. In Angliss et al.
(2001), marine mammal scientists state that there are at least that
many ringed seals in the Beaufort Sea. Frost et al. (1999) reported
that observed densities within the area of industrial activity along
the Beaufort Sea coast were generally similar between 1985-87 and 1996-
98, suggesting that the regional population has been relatively stable
during this 13-year period of industrial activity.
During winter and spring, ringed seals inhabit landfast ice and
offshore pack ice. Seal densities are highest on stable landfast ice
but significant numbers of ringed seals also occur in pack ice (Wiig et
al., 1999). Seals congregate at holes and along cracks or deformations
in the ice (Frost et al., 1999). Breathing holes are established in
landfast ice as the ice forms in autumn and maintained by seals
throughout the winter. Adult ringed seals maintain an average of 3.4
holes per seal (Hammill and Smith, 1989). Some holes may be abandoned
as winter advances, probably in order for seals to conserve energy by
maintaining fewer holes (Brueggeman and Grialou, 2001). As snow
accumulates, ringed seals excavate lairs in snowdrifts surrounding
their breathing holes, which they use for resting and for the birth and
nursing of their single pups in late March to May (McLaren, 1958; Smith
and Stirling, 1975; Kelly and Quakenbush, 1990). Pups have been
observed to enter the water, dive to over 10 m (32.8 ft), and return to
the lair as early as 10 days after birth (Brendan Kelly, personal
communication, June 2002), suggesting pups can survive the cold water
temperatures at a very early age. Mating occurs in late April and May.
From mid-May through July, ringed seals haul out in the open air at
[[Page 14405]]
holes and along cracks to bask in the sun and molt.
The seasonal distribution of ringed seals in the Beaufort Sea is
affected by a number of factors, but a consistent pattern of seal use
has been documented since monitoring began over 20 years ago by using
aerial surveys. Seal densities have historically been substantially
lower in the western than the eastern part of the Beaufort Sea (Burns
and Kelly, 1982; Kelly, 1988). Frost et al. (1999) reported
consistently lower ringed seal densities in the western versus eastern
sectors they surveyed in the Beaufort Sea during 1996, 1997, and 1998.
The relatively low densities appear to be related to much of the area
occurring between the shore and the barrier islands, which is generally
shallow. This area of historically low ringed seal density is also the
focus for much of the recent on-ice seismic surveys.
The estimated number of ringed seals likely to be in the 846-mi\2\
(2,190-km\2\) activity area is less than 3,900 animals. This estimate
is based on a density of 1.73 seals per km\2\, which was derived from
the most current aerial surveys of the region. Frost and Lowry (1999)
reported an observed density of 0.61 ringed seals per km\2\ on the fast
ice from aerial surveys conducted in spring 1997 of an area (Sector B2)
overlapping the activity area, which is in the range of densities
(0.28-0.66) reported for the Northstar project from 1997 to 2001
(Moulton et al., 2001). This value (0.61) was adjusted to account for
seals hauled out but not sighted by observers (x 1.22, based on Frost
et al. (1988)) and seals not hauled out during the surveys (x 2.33,
based on Kelly and Quakenbush (1990)) to obtain the density of 1.73
seals/km2. This estimate covered an area from the coast to about 2-20
miles beyond the activity area, and it assumed that habitat conditions
were uniform and, therefore, it was not adjusted for water depth. Since
a high proportion ( 60 percent) of the activity area is
within water less than 3 m (9.8 ft) deep, which Moulton et al. (2001)
reported for Northstar supported about five times fewer seals (0.12-
0.13 seals/km\2\) than the 0.61 seals reported by Frost and Lowry, the
actual number of ringed seals is probably closer to slightly more than
half of the 3,900 seals or about 2,000 seals. This estimate is
calculated as follows: (1) 1,314 km2 x 0.13 x 1.22 x 2.33 = 486 seals
in area having water depths of 0-3 meter (60 percent) in activity area;
(2) 876 km2 x 0.61 x 1.22 x 2.33 = 1,519 seals in area having water
depths over 3 meters (40 percent) in activity area; and (3) combining
the two numbers gives an estimate of 2,005 seals or approximately 2,000
for the entire activity area. Observed densities of ringed seals
reported over 15 years ago in the region of the activity area from 1985
through 1987 (0.85, 1.09, and 1.11 seals per km2) were not used in this
analysis, since an estimate was available within the last five years
(Frost and Lowry, 1999).
The bearded seal inhabits the Bering, Chukchi, and Beaufort seas
(Burns and Frost, 1979). Numbers are considerably higher in the Bering
and Chukchi seas, particularly during winter and early spring. Early
estimates of bearded seals in the Bering and Chukchi seas range from
250,000 to 300,000 (Popov, 1976; Burns, 1981). Reliable estimates of
bearded seal abundance in Alaska waters are unavailable. Since there is
no evidence of a decline in the population, the population is presumed
to be healthy. Bearded seals are generally associated with pack ice and
only rarely use shorefast ice (Burns and Harbo, 1972). Bearded seals
occasionally have been observed maintaining breathing holes in annual
ice and even hauling out from holes used by ringed seals (Mansfield,
1967; Stirling and Smith, 1977). However, since bearded seals are
normally found in broken ice that is unstable for on-ice seismic
operation, bearded seals will be rarely encountered during seismic
operations.
There are no reliable estimates for bearded seals in the Beaufort
Sea or in the activity area (Angliss et al., 2001), but recent surveys
show that few bearded seals inhabit the activity area during December
through May. An indication of their low numbers is provided by the
results of aerial surveys conducted east of the activity area near the
Northstar and Liberty development sites. Three to 18 bearded seals were
observed in these areas compared to 1,911 to 2,251 ringed seals in the
spring of 1999 through 2001 (Moulton et al., 2001; Moulton and Elliott
2000; Moulton et al., 2000). Similarly small numbers of bearded seals
would be expected to occur in the activity area, where habitat is even
less favorable because of the high proportion of shallow water area.
Potential Effects on Marine Mammals
NMFS and CPA anticipate that only small numbers of ringed seals
and, if encountered, very small numbers of bearded seals will be
affected. Any takes that occur would result from short-term
disturbances by noise and physical activity associated with on-ice
seismic operations. While operations have the potential to disturb and
temporarily displace some seals, any impacts will likely be confined to
small numbers of seals in the immediate vicinity of the activities.
Burns and Kelly (1982) concluded that displacement of ringed seals
in close proximity (within 150 m (492 ft)) to seismic lines does occur,
and ringed seal pupping in shorefast ice habitats within this distance
of an on-ice shot line in favorable ringed seal habitat are likely to
be disturbed by vibroseis operations. However, considering (1) the
limited area of seismic surveys, (2) the non-random distribution of
ringed seals, (3) avoidance by seismic operator of optimal seal habitat
(i.e., areas of extensive pressure ridging and snow accumulation) due
to safety and operational constraints,(4) occurrence of most of the on-
ice seismic surveys in shallow and near shore waters where ringed seal
densities are low, (5) the relatively large size of the ringed seal
population in the Beaufort Sea and throughout Alaska, and (6) the lack
of evidence of on-ice seismic activity negatively affecting the
reproductive viability or distribution of the ringed seal population,
the disturbance is not likely to have any effect on the ringed or
bearded seal populations as a whole.
Aerial survey data collected from 1985 to 1987 and 1997 indicate
that ringed seal densities in the fast ice of the region of the
activity area as well as among different section of the Beaufort Sea
are highly variable among years (Frost et al., 1999). The reported
inter-annual variability in overall average density during these years
in the region of the activity area was 0.61 to 1.11 seals per km\2\.
Based on an estimated rate of temporary displacement determined by
Burns (1981) of 0.6 ringed seals per nm\2\ (0.52 per mile) of area
subjected to seismic activity, a maximum of 832 seals could be
displaced from 1,600 mi (2,575 km) of seismic surveys assuming a
uniform distribution. However, since the distribution is not uniform
and most of the activity area is marginal habitat for ringed seals,
considerably fewer seals would likely be temporarily displaced by the
seismic operations. Furthermore, the proposed seismic operations will
be concentrated in 143 mi\2\ (378 km\2\) or about 17 percent of the 846
mi\2\ (2,190 km\2\) activity area. Consequently, a more accurate
maximum limit of the potential take of ringed seals by the proposed
seismic operations is 340 (17 percent x 2000) seals, which would be
considerably higher than any incidental take of seals in birthing
lairs.
Pup mortality could occur if any of these animals were nursing and
displacement was protracted. However, due to mitigation measures
undertaken by the industry and because it is highly
[[Page 14406]]
unlikely that a nursing female would abandon her pup given the normal
levels of disturbance from the proposed activities and the typical
movement patterns of ringed seal pups among different holes as reported
by Lydersen and Hammill (1993), pup mortality is unlikely. Similarly,
Kelly and Quakenbush (1990) observed that radio-tagged seals used as
many as four lairs spaced as far as 3,437 m (11,276 ft) apart, with
mean distances for males equaling 1,997 m (6,552 ft) and for females
634 m (2,080 ft). In addition, seals have multiple breathing holes.
Pups may use more holes than adults (mean 8.7), but the holes are
generally closer together (Lydersen and Hammill, 1993). Holes have been
found as far apart as 0.9 km (0.56 mi). This pattern of use indicates
that adult seals and pups can move away from seismic activities,
particularly since the seismic equipment does not remain in any
specific area for a prolonged time. Given the small proportion (<1
percent) of the population potentially disturbed by the proposed
activity, impacts are expected to be negligible for the overall ringed
and also bearded seal populations.
Masking effects on pinniped vocalizations and other natural sounds
are expected to be limited. Although pulse repetition rates will be
high during vibroseis surveys, the source levels of those pulses will
be considerably lower than during open-water seismic surveys. This will
considerably reduce the potential for masking.
Potential Effects on Subsistence
Residents of the village of Nuiqsut are the primary subsistence
users in the activity area. The subsistence harvest during winter and
spring is primarily ringed seals, but during the open-water period both
ringed and bearded seals are taken. Nuiqsut hunters may hunt year
round; however, in more recent years most of the harvest has been in
open water instead of the more difficult hunting of seals at holes and
lairs (McLaren, 1958; Nelson, 1969). The most important area for
Nuiqsut hunters is off the Colville River Delta, between Fish Creek and
Pingok Island, which corresponds to approximately the eastern half to
the activity area. Seal hunting occurs in this area by snow machine
before spring break-up and by boat during summer. Subsistence patterns
may be reflected through the harvest data collected in 1992 where
Nuiqsut hunters harvested 22 of 24 ringed seals and all 16 bearded
seals during the open water season from July to October (Fuller and
George, 1997). Only a small number of ringed seals was harvested during
the winter to early spring period, which corresponds to the time of the
proposed on-ice seismic operations.
Based on harvest patterns and other factors, on-ice seismic
operations in the activity area are not expected to have an unmitigable
adverse impact on subsistence uses of ringed and bearded seals because:
(1) Operations would end before spring breakup, after which
subsistence hunters harvest most of their seals.
(2) Operations would temporarily displace relatively few seals,
since most of the habitat in the activity area is marginal to poor and
supports relatively low densities of seals during winter. Displaced
seals would likely move a short distance and remain in the area for
potential harvest by native hunters (Frost and Lowry, 1988; Kelly et
al., 1988).
(3) The area where seismic operations would be conducted is small
compared to the large Beaufort Sea subsistence hunting area associated
with the extremely wide distribution of ringed seals.
In order to ensure the least practicable adverse impact on the
species and the subsistence use of ringed seals, all activities will be
conducted as far as practicable from any observed ringed seal
structure, and crews will be required to avoid hunters and the
locations of any seals being hunted in the activity area, whenever
possible. Finally, the applicant will consult with subsistence hunters
of Nuiqsut and provide the community, the North Slope Borough, and the
Inupiat Community of the North Slope with information about its planned
activities (timing and extent) before initiating any on-ice seismic
activities.
Mitigation
Similar to work in previous years, NMFS expects the following
mitigation will be undertaken by the applicant to ensure that any
taking will be at the lowest level practicable. All activities will be
required to be conducted in a manner that minimizes adverse effects on
ringed and bearded seals and their habitat. Activities must be
conducted as far as practicable from any observed ringed seals or
ringed seal lair. For example, no energy source may be placed over an
observed ringed seal lair and only vibrator-type energy-source
equipment will be used. Seismic crews will receive training so that
they can recognize potential ringed seal lairs and adjust their seismic
operations. Furthermore, if seismic operations go beyond March 20, 2003
in waters [gteqt] 3 m (9.8 ft), a survey using trained dogs will be
completed in all areas where surface blading will be conducted. This
survey will identify all active seal holes/ birthing lairs or hole/lair
habitats so they can be avoided by seismic and camp operations to the
greatest extent practicable. If trained dogs are not available, then
the NMFS Regional Administrator or his designee will be promptly
notified to determine possible alternative monitoring that would
identify potential ringed seal habitat by trained marine mammal
biologists based on the characteristics of the ice (i.e., deformation,
cracks, etc.).
Monitoring and Reporting
Ringed seal pupping occurs in lairs from late March to mid-to-late
April (Smith and Hammill, 1981). Prior to commencing on-ice seismic
surveys after March 20th, a survey using experienced field personnel
and trained dogs will be conducted to identify potential seal
structures along the planned on-ice seismic transmission routes. The
seal structure survey will be conducted before selection of precise
transit routes to ensure that seals, particularly pups, are not injured
by equipment. The locations of all seal structures will be recorded by
Global Positioning System (GPS), staked, and flagged with surveyor's
tape. Surveys will be conducted 150 m (492 ft) to each side of the
transit routes. Actual width of route may vary depending on wind speed
and direction, which strongly influence the efficiency and
effectiveness of dogs locating seal structures. Survey will only be
conducted in the portions of the activity area where water depths
exceed 3 m (9.8 ft). Few, if any, seals inhabit ice-covered waters
below 3 m (9.8 ft) due to water freezing to the bottom or poor prey
availability caused by the limited amount of ice-free water.
The level of take, while anticipated to be negligible, will be
assessed by conducting a second seal structure survey immediately after
the end of the seismic surveys. A single on-ice survey will be
conducted by biologists on snowmachines using a GPS to relocate and
determine the status of seal structures located during the initial
survey. The status (active vs. inactive) of each structure will be
determined to assess the level of incidental take by seismic
operations. The number of active seal structures abandoned between the
initial survey and the final survey will be the basis for enumerating
take. If dogs are not available for the initial survey, take will be
determined by using observed densities of seal on ice reported by
Moulton et al. (2001) for the Northstar project, which is
[[Page 14407]]
approximately 20 nm (37 km) from the eastern edge of the proposed
activity area.
In the event that seismic surveys can be completed in that portion
of the activity area [gteqt] 3 m (9.8 ft) before mid-March, no field
surveys would be conducted of seal structures. Under this scenario,
surveys would be completed before pups are born and disturbance would
be negligible. Therefore, take estimates would be determined for only
that portion of the activity area exposed to seismic surveys after
March 20, which would be in water 3 m (9.8 ft) or less deep. Take for
this area would be estimated by using the observed density (13/100
km\2\) reported by Moulton et al. (2001) for water depths between 0 to
3 m (0 to 9.8 ft) in the Northstar project area, which is the only
source of a density estimate stratified by water depth for the Beaufort
Sea. This would be an overestimation requiring a substantial downward
adjustment to reflect the actual take of seals using lairs, since few
if any of the structures in these water depths would be used for
birthing, and Moulton et al. (2001) estimate includes all seals. This
monitoring program was reviewed at the fall 2002 on-ice meeting
sponsored by the National Marine Mammal Laboratory, NMFS, in Seattle
and found acceptable.
An annual report must be submitted to NMFS within 90 days of
completing the year's activities.
National Environmental Policy Act (NEPA)
As a result of the information provided in EAs prepared in 1993 and
1998 for winter seismic activities, NOAA concluded that implementation
of either the preferred alternative or other alternatives identified in
the EA would not have a significant impact on the human environment.
Therefore, an Environmental Impact Statement was not prepared.
Accordingly, because the proposed action discussed in this document is
not substantially different from the 1992 and 1998 actions, and because
a reference search has indicated that no significant new scientific
information or analyses have been developed in the past several years
significant enough to warrant new NEPA documentation, this action is
categorically excluded from further review under NOAA Administrative
Order 216-6.
Endangered Species Act (ESA)
NMFS has determined that no species listed as threatened or
endangered under the ESA will be affected by issuing an authorization
under section 101(a)(5)(D) of the MMPA.
Conclusions
The anticipated impact of winter seismic activities on the species
or stock of ringed and bearded seals is expected to be negligible for
the following reasons:
(1) The activity area supports a small proportion (<1 percent) of
the ringed seal populations in the Beaufort Sea;
(2) Most of the winter-run seismic lines will be on ice over
shallow water where ringed seals are absent or present in very low
abundance. Over 60 percent of the activity area is near shore and/or in
water less than 3 m (9.8 ft) deep, which is generally considered poor
seal habitat. Moulton et al. (2001) reported that only 6 percent of 660
ringed seals observed on ice in the Northstar project area were in
water between 0 to 3 m (0 to 9.8 ft)deep.
(3) Seismic operators will avoid moderate and large pressure
ridges, where seal and pupping lairs are likely to be most numerous,
for reasons of safety and because of normal operational constraints;
(4) Many of the on-ice seismic lines and connecting ice roads will
be laid out and explored during January and February, when many ringed
seals are still transient, and considerably before the spring pupping
season;
(5) The sounds from energy produced by vibrators used during on-ice
seismic programs typically are at frequencies well below those used by
ringed seals to communicate (1000 Hz). Thus, ringed seal hearing is not
likely to be very good at those frequencies and seismic sounds are not
likely to have strong masking effects on ringed seal calls. This effect
is further moderated by the quiet intervals between seismic energy
transmissions.
(6) There has been no major displacement of seals away from on-ice
seismic operations (Frost and Lowry, 1988). Further confirmation of
this lack of major response to industrial activity is illustrated by
the fact that there has been no major displacement of seals near the
Northstar Project. Studies at Northstar have shown a continued presence
of ringed seals throughout winter and creation of new seal structures
(Williams et al., 2001).
(7) Although seals may abandon structures near seismic activity,
studies have not demonstrated a cause and effect relationship between
abandonment and seismic activity or biologically significant impact on
ringed seals. Studies by Williams et al. (2001), Kelley et al. (1986,
1988) and Kelly and Quakenbush (1990) have shown that abandonment of
holes and lairs and establishment or re-occupancy of new ones is an
ongoing natural occurrence, with or without human presence. Link et al.
(1999) compared ringed seal densities between areas with and without
vibroseis activity and found densities were highly variable within each
area and inconsistent between areas (densities were lower for 5 days,
equal for 1 day, and higher for 1 day in vibroseis area), suggesting
other factors beyond the seismic activity likely influenced seal use
patterns. Consequently, a wide variety of natural factors influence
this patterns of seal use including time of day, weather, season, ice
deformation, ice thickness, accumulation of snow, food availability and
predators as well as ring seal behavior and populations dynamics.
In winter, bearded seals are restricted to cracks, broken ice, and
other openings in the ice. On-ice seismic operations avoid those areas
for safety reasons. Therefore, any exposure of bearded seals to on-ice
seismic operations would be limited to distant and transient exposure.
Bearded seals exposed to a distant on-ice seismic operation might dive
into the water. Consequently, no significant effects on individual
bearded seals or their population are expected, and the number of
individuals that might be temporarily disturbed would be very low.
As a result, CPA believes the effects of on-ice seismic are
expected to be limited to short-term and localized behavioral changes
involving relatively small numbers of seals. As NMFS came to a similar
finding in the EA prepared in 1998 for on-ice seismic activity in the
Beaufort Sea, NMFS has determined that these changes in behavior are
expected to be negligible (NMFS, 1998). Therefore, the potential
effects of the proposed on-ice seismic operations during 2003 are
unlikely to result in more than small numbers of seals being affected,
will have no more than a negligible impact on ringed and bearded seal
stocks and will not have an unmitigable adverse impact on subsistence
uses of these two species.
Authorization
For the reasons described previously in this document, NMFS has
issued an IHA to CPA for a 5-month period, provided the mitigation,
monitoring, and reporting requirements described in this document and
the IHA are undertaken.
[[Page 14408]]
Dated: March 19, 2003.
Laurie K. Allen,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 03-7069 Filed 3-24-03; 8:45 am]
BILLING CODE 3510-22-S