[Federal Register Volume 67, Number 62 (Monday, April 1, 2002)]
[Notices]
[Pages 15360-15365]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-7813]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[I.D. 030702A]
Small Takes of Marine Mammals Incidental to Specified Activities;
Seismic Reflection Data off Southern California
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 authorization; request for comments.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from the U.S. Geological Survey
(USGS) for an authorization to take small numbers of marine mammals by
harassment incidental to collecting marine seismic reflection data to
investigate the landslide and earthquake hazards off Southern
California. Under the Marine Mammal Protection Act (MMPA), NMFS is
requesting comments on its proposal to authorize the USGS to
incidentally take, by harassment, small numbers of marine mammals in
the above mentioned area during June, 2002.
DATES: Comments and information must be received no later than May 1,
2002.
ADDRESSES: Comments on the application should be addressed to Donna
Wieting, Chief, Marine Mammal Conservation Division, Office of
Protected Resources, NMFS, 1315 East-West Highway, Silver Spring, MD
20910-3225. A copy of the application, which includes a list of
references used in this document, and other documents referenced herein
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, or Christina Fahy, NMFS,
562-960-4023.
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, 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
takings are set forth. NMFS has defined ``negligible impact'' in 50 CFR
216.103 as ``an impact resulting from the specified activity that
cannot be reasonably expected to, and is not reasonably likely to,
adversely affect the species or stock through effects on annual rates
of recruitment or survival.''
Subsection 101(a)(5)(D) of the MMPA established an expedited
process by which citizens of the United States can apply for an
authorization to incidentally take small numbers of marine mammals by
harassment. The MMPA defines ``harassment'' as:
Any act of pursuit, torment, or annoyance which (i) has the
potential to injure a marine mammal or marine mammal stock in the
wild; or (ii) has the potential to disturb a marine mammal or marine
mammal stock in the wild by causing disruption of behavioral
patterns, including, but not limited to, migration, breathing,
nursing, breeding, feeding, or sheltering.
Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS
review of an application followed by a 30-day public notice and comment
period on any proposed authorizations for the incidental harassment of
small numbers of marine mammals. Within 45 days of the close of the
comment period, NMFS must either issue or deny issuance of the
authorization.
Summary of Request
The USGS proposes to conduct a high-resolution seismic-reflection
survey offshore from southern California for two weeks during June
2002. The USGS will collect this seismic-reflection data to investigate
the hazards posed by landslides, tsunamis, and potential earthquake
faults in the nearshore region from Ventura to Santa Barbara, CA. This
task is part of a multiyear hazard analysis that requires high-
resolution, seismic-reflection data using several acoustic sources. In
addition, a few days of survey time will be used to
[[Page 15361]]
conduct a seafloor imaging survey in support of environmental studies
in the area offshore Pt. Conception.
The USGS plans to collect seismic-reflection data using three basic
instrument systems:
(1) A Huntec\TM\ or a Geopulse\TM\ boomer sound-source to collect
high-resolution seismic-reflection data of the sub-seafloor;
(2) A high-resolution multi-channel system for which the primary
source will be either a 2-kilo-Joule (kJ) sparker system for shallow
water or a small GI airgun in deeper water. The type of sparker to be
used will depend on the results of a sparker feasibility study
completed earlier this year in the Seattle, Washington area. A 250-m-
long (820.2-ft) hydrophone streamer is used for both multi-channel
sources.
(3) A Klein sidescan sonar for the environmental survey off Pt.
Conception, CA.
The high-resolution Huntec\TM\ boomer system uses an electrically
powered sound source that is towed behind the ship at depths between 30
m (98.4 ft) and 160 m (525 ft) below the sea surface. The hydrophone
arrays for listening are attached to the tow vehicle that houses the
sound source. The USGS plans to use the Huntec\TM\ primarily in water
depths greater than 300 m (984.2 ft). The system is triggered at 0.5-to
1.25-second intervals, depending upon the source tow depth. This system
provides detailed information about stratified sediment, so that dates
obtained from fossils in sediment samples can be correlated with
episodes of fault offset. The sound pressure level (SPL) for the
Huntec\TM\ unit is 205 dB re 1 Pa-m (root-mean-squared (RMS)).
The output-sound bandwidth is 0.5 kHz to 8 kHz, with the main peak at
4.5 kHz.
The USGS plans to use the surface-towed Geopulse\TM\ boomer system
in the shallow water parts of the survey area, typically in water
depths from 20 m to 300 m (65.6 to 984.2 ft). The sound source consists
of two Geopulse 5813A boomer plates mounted on a catamaran sled built
in-house. The catamaran is towed just behind the vessel, while the 5-m-
long (16.4-ft) hydrophone streamer is usually towed from a boom on one
side of the vessel. The source level for the Geopulse is 204 dB re 1
Pa-m (RMS), and its effective bandwidth is about 0.75 to 3.5
kHz. The firing rate is generally 0.5 to 1 second interval.
The primary sound source for the high-resolution multi-channel
system will be a 2.0 kJ sparker system such as the SQUID 2000\TM\
minisparker system manufactured by Applied Acoustic Engineering, Inc.
This minisparker includes electrodes that are mounted on a small
pontoon sled. The electrodes simultaneously discharge electric current
through the seawater to an electrical ground. This discharge creates an
acoustic signal. The pontoon sled that supports the minisparker is
towed on the sea surface, approximately 5 meters (16.4 ft) behind the
ship.
Source characteristics of the SQUID 2000\TM\ provided by the
manufacturer show an SPL of 209 dB re 1 Pa-m (RMS). The
amplitude spectrum of this pulse indicates that most of the sound
energy lies between 150 Hz and 1700 Hz, and the peak amplitude is at
900 Hz. The output sound pulse of the minisparker has a duration of
about 0.8 ms. When operated at sea for the proposed multichannel
seismic-reflection survey, the minisparker will be discharged every 1
to 4 seconds.
The second source for the multi-channel system is a small airgun of
special type called a generator-injector, or GI gun (trademark of
Seismic Systems, Inc., Houston, TX). This type of airgun consists of
two small airguns within a single steel body. The two small airguns are
fired sequentially, with the precise timing required to nullify the
bubble oscillations that typify sound pulses from a single airgun of
common type. These oscillations impede detailed analysis of fault
structure. For arrays consisting of many airguns, bubble oscillations
are cancelled by careful selection of airgun sizes. The GI gun is a
mini-array that is carefully adjusted to achieve the desired bubble
cancellation. Airguns and GI guns with similar chamber sizes have
similar peak output pressures. The GI gun for this survey has two
chambers of equal size (35 in\3\) and the gun will be fired every 12
seconds. Compressed air delivered to the GI gun will have a pressure of
about 3000 psi. The gun will be towed 5 meters (16.4 ft) behind the
vessel and suspended from a float to maintain a depth of about 1 m (3.2
ft).
The manufacturer's literature indicates that a GI gun of the size
the USGS will use has an SPL of about 220 dB re 1 Pa-m (RMS).
The GI gun's output sound pulse has a duration of about 10 ms. The
amplitude spectrum of this pulse, as shown by the manufacturer's data,
indicates that most of the sound energy is at frequencies below 500 Hz.
Field measurements by USGS personnel indicates that the GI gun produces
low-sound-amplitudes at frequencies above 500 Hz. Thus high-amplitude
sound from this source is at frequencies that are outside the main
hearing band of odontocetes and pinnipeds (Richardson et al., 1995).
The environmental survey off Pt. Conception will be accomplished
with sidescan-sonar surveying. The system that will be used will be the
Klein 3000 or the Klein 2000. The Klein 2000 sidescan sonar uses an
electrically powered sound source. In operation, the sound source, or
``fish'', is towed behind the research vessel at depths of 1 to 10 m
(3.2 to 32.8 ft) below the sea surface. The unit emits a short pulse of
sound about every 0.25 second; the interval depends on the swath width
(i.e., the area of seafloor to be imaged). The sidescan-sonar system
measures the return time and intensity of echoes to create a high-
resolution image of the seafloor that is similar to an air photo on
land. The sidescan system has a sound pressure level (SPL) of about 210
dB re 1 Pa-m (RMS). The output sound pulse is very short, with
a time duration of less than 0.1 ms. The frequency bandwidth of the
outgoing signal is 100kHz or 500 kHz.
The Klein 3000 is a system that has just been developed and its
operating frequencies are 128kHz and 445 kHz. The SPL for these
frequencies are 212 dB re 1 Pa-m (RMS) for the 125 kHz and 200
dB re 1 Pa-m (RMS) for the 455 kHz source. The pulse lengths
are selectable from among 50/100/200/400 ms.
The work is planned for thirteen days during June 2002. The
possible operational window is from mid-May to mid-August 2002, but the
preferred time is early June. At this time, the USGS is in the process
of leasing a vessel, and exact availability is not yet known. The
primary work area (70 percent of the time) is between Pt. Dume and
offshore Gaviota, California, in the western Santa Monica Basin and
Santa Barbara Channel. The secondary work area is offshore between Pt.
Conception and Pt. Arguello (but staying within 30 km (18.6 mi) of the
coast). If authorized, the USGS will work inside a small part of the
Channel Islands Marine Sanctuary. Some work might be attempted during
transit between the two work areas.
Description of Habitat and Marine Mammals Affected by the Activity
The Southern California Bight supports a diverse assemblage of 29
species of cetaceans (whales, dolphins and porpoises) and 6 species of
pinnipeds (seals and sea lions). The species of marine mammals that are
likely to be present in the seismic research area include the
bottlenose dolphin (Tursiops truncatus), common dolphin (Phocoena
phocoena), killer whale (Orcinus orca), Pacific white-sided dolphin
(Lagenorhynchus obliquidens), northern right whale dolphin
(Lissodelphis borealis), Risso's dolphin (Grampus griseus), pilot
whales
[[Page 15362]]
(Globicephala macrorhynchus), Dall's porpoise (Phocoenoides dalli),
sperm whale (Physeter macrocephalus), humpback whale (Megaptera
novaengliae), gray whale (Eschrichtius robustus), blue whale
(Balaenoptera musculus), minke whale (Balaenoptera acutorostrata), fin
whales (Balaenoptera physalus), harbor seal (Phoca vitulina), elephant
seal (Mirounga angustirostris), northern sea lion (Eumetopias jubatus),
California sea lion (Zalophus californianus), northern fur seal
(Callorhinus ursinus) and sea otters (Enhydra lutris). General
information on these species can be found in the USGS application and
in Forney et al. (2000). Forney et al. (2000) is available at the
following URL:
http://www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/sars.html Please refer to these documents for information on these
species in California waters.
Potential Effects of Marine Seismic Reflection Studies on Marine
Mammals
Discussion
Disturbance by acoustic noise is the principal means of taking
incidental to this activity. Vessel noise may provide a secondary
source. Also, the physical presence of vessels could also lead to some
non-acoustic effects involving visual or other cues.
The effects of underwater sounds on marine mammals are highly
variable, and can be categorized as follows: (1) The sounds may be too
weak to be heard at the location of the animal (i.e. lower than the
prevailing ambient noise level, the hearing threshold of the animal at
relevant frequencies, or both); (2) the sounds may be audible but not
strong enough to elicit any overt behavioral response; (3) the sounds
may elicit behavioral reactions of variable conspicuousness and
variable relevance to the well being of the animal; these can range
from subtle effects on respiration or other behaviors (detectable only
by statistical analysis) to active avoidance reactions; (4) upon
repeated exposure, animals may exhibit diminishing responsiveness
(habituation), or disturbance effects may persist (the latter is most
likely with sounds that are highly variable in characteristics,
unpredictable in occurrence, and associated with situations that the
animal perceives as a threat); (5) any sound that is strong enough to
be heard has the potential to reduce (mask) the ability of marine
mammals to hear natural sounds at similar frequencies, including calls
from conspecifics and/or echolocation sounds, and environmental sounds
such as storms and surf noise; and (6) very strong sounds have the
potential to cause either a temporary or a permanent reduction in
hearing sensitivity (i.e., temporary threshold shift (TTS) or permanent
threshold shift (PTS), respectively). In addition, intense acoustic or
explosive events may cause trauma to tissues associated with organs
vital for hearing, sound production, respiration and other functions.
This trauma may include minor to severe hemorrhage.
Few data on the effects of non-explosive sounds on hearing
thresholds of marine mammals have been obtained. However, in
terrestrial mammals (and presumably in marine mammals), received sound
levels must far exceed the animal's hearing threshold for there to be
any TTS and must be even higher for there to be risk of PTS (Richardson
et al., 1995).
Depending upon ambient conditions and the sensitivity of the
receptor, underwater sounds produced by 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. Harassment is presumed to occur when marine
mammals in the vicinity of the acoustic source (or vessel) show a
significant behavioral response to the generated sounds or visual cues.
Seismic pulses are known to cause some species of whales, including
gray and bowhead whales, to behaviorally respond within a distance of
several kilometers (Richardson et al., 1995). Although some limited
masking of low-frequency sounds is a possibility for those species of
whales using low frequencies for communication, the intermittent nature
of the acoustic pulses created by the planned survey's instruments will
limit the extent of masking. Bowhead whales, for example, 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).
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 season.
Behavioral changes may be subtle alterations in surface-dive-
respiration 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.
Hearing damage is not expected to occur during the project. While
it is not known whether a marine mammal very close to one of the
acoustic devices would be at risk of temporary or permanent hearing
impairment, TTS is a theoretical possibility for animals within a few
hundred meters (Richardson et al., 1995), if the SPL of an acoustic
source is of sufficient intensity, such as with large seismic airgun
arrays. However, considering the low intensity of the proposed acoustic
devices, and the planned monitoring and mitigation measures (described
later in this document), which are designed to detect marine mammals
occurring near the acoustic sources and to avoid, to the greatest
extent practicable, exposing them to sound pulses that have any
possibility of causing hearing damage, neither TTS, nor PTS are
considered likely.
Maximum Sound-Exposure Levels for Marine Mammals
The adverse effects of underwater sound on mammals have been
documented for exposure times that for up to several minutes, but
adverse effects have not been documented for the brief pulses typical
of the minisparker (0.8 ms) and the Huntec system (typically 0.3 ms).
For impulse noise, NMFS has previously established that activities
should avoid, to the greatest extent practicable, exposing mysticetes
and sperm whales to an SPL of 180 dB re 1 Pa-m (RMS) or
higher. For odontocetes and pinnipeds, activities should avoid, to the
greatest extent practicable, exceeding a level of 190 dB re 1
Pa-m (RMS). These determinations were based on findings at the
High-Energy Seismic Workshop held at Pepperdine University in 1997 as
updated by the NMFS' Acoustics Workshop held in Silver Spring, MD in
1999. In 1999 however, the California Coastal Commission (CCC) limited
this maximum sound-exposure level to 180 dB re 1 Pa-m (RMS)
for all marine mammals, including pinnipeds, within the coastal zone of
California and NMFS expects that the CCC will require similar
limitations for this action.
However, current scientific consensus indicates that a safe level
for impulse sounds for pinnipeds that avoids TTS is higher than the
level indicated for
[[Page 15363]]
cetaceans (e.g., 180 dB). As a result, although scientists have
preliminarily established an SPL of 190 dB re 1 Pa-m (RMS) as
a safe level for pinnipeds underwater, and while NMFS adopts this
information as the best scientific information available, the USGS has
agreed to abide by the conditions contained in its CCC consistency
determination.
NMFS notes moreover, that the recent precautionary application of a
180-dB safety zone for protecting marine mammals does not necessarily
mean that animals entering that zone will be adversely affected. It
simply means that animals have the potential to incur a temporary
elevation in hearing threshold (i.e., TTS), lasting, at worst, for a
few minutes at the 180 dB sound pressure level.
The USGS has provided two estimates of how close marine mammals can
approach each sound source before it needs to be shut off. The first
estimate follows the procedure required by the CCC in 1999, in that
underwater sound is assumed to attenuate with distance according to
20log(R), and the maximum SPL to which marine mammals can be exposed is
180 dB re 1Pa-m (RMS). The alternative estimate of safe
distance is proposed for operations in shallow water. In shallow water,
sound from the sources will decay with distance more sharply than
20log(R) because some of the sound energy will exit the water and
penetrate the seafloor when the source is physically close to the
seafloor.
The zone of impact for the sound sources is a circle whose radius
is the distance from the source to where the SPL is reduced to 180 dB
re 1 Pa-m (RMS). In the deeper water (>50 m; >164 ft) areas of
the proposed survey, for a 20log(R) sound attenuation, the zone of
impact for a 209 dB (RMS) minisparker source has a radius of 28 m (92
ft). The 204 dB Geopulse\TM\ and 205 dB Huntec\TM\ boomers yield radii
of 16 and 18 m (52.5 and 59 ft) respectively. The 210 dB Klein sidescan
yields a safety radius of 32 m (105 ft), and the 220 dB GI gun yields a
safety radius of 100 m (328 ft). The USGS proposes that safety zones of
30 m (98 ft) around the boomers, minisparker, sidescan fish, and of 100
m (328 ft) around the airgun be used in water deeper than 50 m (164
ft).
In water 50 m (164 ft) deep, underwater sound commonly attenuates
more sharply than 20log(R). In 1999, the USGS measured a sound
attenuation of 27log(R) off southern California, so it proposes that
for inshore areas, underwater sound attenuates approximately like
25log(R). Strictly for inshore areas, then, an attenuation of 25log(R)
yields zones of influence for the boomers of 10 m (32.8 ft), for
minisparker 15 m (49 ft), and for sidescan 20 m (65.6 ft).
Potential Level of Taking by Harassment of Marine Mammals
The following summary is from a report by Calambokidis and Chandler
(2001) that was submitted in compliance with an Incidental Harassment
Authorization (IHA) issued to the USGS on June 5, 2000 (65 FR 39871,
June 28, 2000). During a similar acoustic survey in early June, 2000,
there were a total of 241 marine mammal sightings (not including re-
sightings), representing at least 11 species and 4,792 marine mammals.
(Sighting a marine mammal should not be interpreted to mean that the
animal was being harassed.) Small cetaceans were the most numerous and
accounted for 54 percent of the sightings and 96 percent of the
animals. Common dolphins made up 74 sightings and 3,764 of the sighted
animals. Risso's dolphins, bottlenose dolphins and Dall's porpoises
were seen in smaller numbers. Pinnipeds accounted for 98 sightings and
these were predominantly California sea lions. Smaller numbers of
harbor seals and a single elephant seal were also sighted. Four species
of large cetaceans were sighted in small numbers. Blue whales were most
common with 5 sightings of single animals. Fin, humpback and minke
whales were each sighted once or twice. Sighting rates versus acoustic
source appeared to be related to habitat of operations and not to the
sound source itself.
The sound source was shutdown a total of 40 times (22 daylight and
18 nightime). Shutdowns were in response to five different species.
Common dolphins triggered a shutdown in 29 instances; Risso's dolphin,
bottlenose dolphins and California sea lions each resulted in 3 to 4
shutdowns each. The only shutdown for a large whale was for a sighting
of a blue whale which, although still outside the 250-m (820-ft)
mitigation zone, was prompted as precautionary measure.
The high proportion of shutdowns caused by common dolphins was a
result both of their being one of the most common species in the area
and their tendency to approach the ship. Common dolphins accounted for
31 percent of marine mammal sightings but were responsible for 72
percent of the shutdowns. California sea lions, which accounted for 36
percent of the sightings were responsible for only 7 percent of the
shutdowns. Although other dolphin species were less common, both
Risso's and bottlenose dolphins had shutdown rates that were similar to
common dolphins. Overall, 30 percent of small cetacean sightings made
while the sound source was operational led to shutdowns compared to
only 4 percent of pinniped sightings. A low proportion of large whale
sightings led to shutdowns. The 11 sightings of whales made during
sound source operations led to only a single precautionary shutdown.
Behavioral observations were made both while the sources were on
and when they were off. For small dolphins and pinnipeds there did not
appear to be a difference in behavior between the two operational
modes. There was also no apparent difference in the orientation
(direction of swimming) of these animals in relation to transmissions.
Breaching was observed in two cases for large cetaceans; a minke whale
and a group of two humpback whales. Sound transmissions were occurring
only during the minke whale sighting.
The Need for 24-hour Seismic Operations
The USGS has requested that the IHA allow for 24-hour operations,
specifically for the minisparker and/or boomers or sidescan. The
reasons for around-the-clock operation that benefit the environment
are: (1) When the sound sources cease to operate, marine mammals might
move back into the survey area and incur an increased potential for
harm when operations resume, and (2) Daylight-only operations prolong
activities in a given area, thus increasing the likelihood that marine
mammals will be harassed.
The 2002 survey will require only two weeks, and the ship will be
moving continuously through the Santa Barbara Channel, so no single
area will see long-term activity. The USGS believes that the best
course is to complete the survey as expeditiously as possible. Also,
operating less than 24 hours each day incurs substantially increased
cost for the leased ship, for which the USGS has not been provided
funding (Normark et al., 1999b). The ship schedule provides a narrow
time window for this project; typically, other experiments are
scheduled to precede and follow the USGS project. Thus they are not
able arbitrarily to extend the survey time to include large delays for
dark or poor visibility. Delays could require scheduling additional
surveys in future years to complete the missed work.
Mitigation
Several mitigation measures to reduce the potential for marine
mammal
[[Page 15364]]
harassment will be implemented by USGS as part of their proposed
activity. These include:
(1) The survey is planned for June, when gray whales are not
migrating.
(2) The smallest possible acoustic sources have been selected to
minimize the chances of incidental harassment.
(3) To avoid potential incidental injury to marine mammals, safety
zones will be established and monitored continuously. Whenever the
seismic source(s) approaches a marine mammal closer than the assigned
safe distance the USGS will shut them down.
(4) For mysticetes and sperm whales, the marine mammal species near
the survey area that are considered to be most sensitive to the
frequency and intensity of sound that will be emitted by the seismic
sources, operations will cease when members of these species approach
within 250 m (820 ft) of the sound source.
(5) For odontocetes, with their lower sensitivity to low frequency
sound, operations will cease when these animals approach a safety zone
of 30 m (98.4 ft) from the boomer, minisparker, or sidescan fish, and a
zone of 100 m (328 ft) from the airgun.
(6) For pinnipeds (seals and sealions): if the research vessel
approaches a pinniped, a safety radius of 30 m (98.4 ft) around the
boomer, minisparker, or sidescan fish and 100 m (328 ft) around the
airgun will be maintained from the animal(s). However, if a pinniped
approaches the acoustic source, the USGS will not be required to shut
it down. Experience indicates that pinnipeds will come from great
distances to scrutinize seismic-reflection operations. Seals have been
observed swimming within airgun bubbles, 10 m (33 ft) away from active
arrays. More recently, Canadian scientists, who were using a high-
frequency seismic system that produced sound closer to pinniped hearing
than will the USGS sources, describe how seals frequently approached
close to the seismic source, presumably out of curiosity. Therefore,
because pinnipeds indicate no adverse reaction to seismic noise, the
above-mentioned mitigation plan is proposed. In addition, the USGS will
gather information on how often pinnipeds approach the sound source(s)
on their own volition, and what effect the source(s) appears to have on
them.
(7) During seismic-reflection survey operations, the ship's speed
will be 4 to 5 knots so that when the seismic sources are being
discharged, nearby marine mammals will have gradual warning of the
ship's approach and can move away.
(8) The USGS will have marine biologists onboard the seismic vessel
who will have the authority to stop seismic operations whenever a
mammal enters the safety zone. These observers will monitor the safety
zone to ensure that no marine mammals enter the zone, and record
observations on marine mammal abundance and behavior.
(9) If observations are made that one or more marine mammals of any
species are attempting to beach themselves when the seismic source is
operating in the vicinity of the beaching, the seismic sources will be
immediately shut off and NMFS contacted.
(10) Upon notification by a local stranding network that a marine
mammal has stranded where the acoustic sources had recently been
operated, NMFS will investigate the stranding to determine whether a
reasonable chance exists that the seismic survey caused the animal's
death. If NMFS determines, based upon a necropsy of the animal(s), that
the death was likely due to the seismic source, the survey shall cease
until procedures are altered to eliminate the potential for future
deaths.
Monitoring
Monitoring of marine mammals while the sparker or airgun sound
sources are active will be conducted continuously. Trained marine
mammal observers will be onboard the vessel to mitigate the potential
environmental impact from either of the two systems and to gather data
on the species, number, and reaction of marine mammals to the sources.
Each observer will use equipment, such as Tasco 7x50 binoculars with
internal compasses and reticules, to record the horizontal and vertical
angle to sighted mammals. Nighttime operations in shallow water will be
conducted with a spotlight to illuminate the radius of influence around
the minisparker tow sled and observers will have night-vision goggles.
Monitoring data to be recorded during seismic-reflection operations
include which observer is on duty and what the weather conditions are
like, such as Beaufort Sea state, wind speed, cloud cover, swell
height, precipitation and visibility. For each mammal sighting the
observer will record the time, bearing and reticule readings, species,
group size, and the animal's surface behavior and orientation.
Observers will instruct geologists to shut all active seismic sources
whenever a marine mammal enters a safety zone.
Reporting
The USGS will provide an initial report to NMFS within 120 days of
the completion of the marine seismic reflection survey project. This
report will provide dates and locations of seismic operations, details
of marine mammal sightings, and estimates of the amount and nature of
all takes by harassment. A final technical report will be provided by
USGS within 1 year of completion of the project. 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 has begun
consultation on the proposed issuance of an IHA. Consultation will be
concluded upon completion of the comment period and consideration of
those comments in the final determination on issuance of an
authorization.
National Environmental Policy Act (NEPA)
In conjunction with the promulgation of regulations implementing
section 101(a)(5)(D) of the MMPA, NMFS completed an Environmental
Assessment (EA) on May 9, 1995 that addressed the impacts on the human
environment from issuance of IHAs and the alternatives to that action.
NMFS' analysis resulted in a Finding of No Significant Impact (FONSI).
In addition, this proposed seismic reflection survey will use acoustic
instruments that are significantly less intense and thereby have a
significantly lower impact on the marine environment than acoustic
sources used in other surveys for which EAs and resulting FONSIs have
been prepared previously. Accordingly, this proposed action qualifies
for a categorical exclusion under NEPA and, therefore, a new EA will
not be prepared. A copy of relevant previous EAs are available (see
ADDRESSES).
Preliminary Conclusions
NMFS has preliminarily determined that the short-term impact of
conducting a marine seismic survey in southern California waters will
result, at worst, in a temporary modification in behavior by certain
species of pinnipeds, and possibly some individual cetaceans. While
behavioral modifications may be made by certain species of marine
mammals to avoid the resultant noise from airgun arrays, this
behavioral change is expected to result in the harassment of only small
numbers of each of several species of marine mammals and would have no
more than a negligible impact on these affected species or stocks.
In addition, no take by injury and/or death is anticipated and
takes by harassment will be at the lowest level
[[Page 15365]]
practicable due to incorporation of the mitigation measures mentioned
previously. Known rookeries, mating grounds, areas of concentrated
feeding, or other areas of special significance for marine mammals that
occur within or near the planned area of operations during the season
of operations are unlikely to be affected.
As a result, NMFS proposes to issue an IHA to the USGS for the
possible harassment of small numbers of several species of marine
mammals incidental to collecting marine seismic reflection data in
southern California waters, provided the above-mentioned mitigation,
monitoring, and reporting requirements are incorporated.
Information Solicited
NMFS requests interested persons to submit comments, information,
and suggestions concerning this request (see ADDRESSES).
Dated: March 26, 2002.
Wanda Cain,
Acting Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 02-7813 Filed 3-29-02; 8:45 am]
BILLING CODE 3510-22-S