Small Takes of Marine Mammals Incidental to Specified Activities; Seismic Reflection Data off Southern California

Note: EPA no longer updates this information, but it may be useful as a reference or resource.
 
[Federal Register: June 24, 2002 (Volume 67, Number 121)]
[Notices]
[Page 42541-42547]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24jn02-40]

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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 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 the U.S. Geological 
Survey (USGS) to take small numbers of marine mammals by harassment 
incidental to collecting marine seismic reflection data while 
investigating the landslide and earthquake hazards off Southern 
California.

DATES: This authorization is effective from June 13, 2002, through 
September 30, 2002.

ADDRESSES: 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 Donna Wieting, Chief, Marine

[[Page 42542]]

Mammal Conservation Division, Office of Protected Resources, NMFS, 1315 
East-West Highway, Silver Spring, MD 20910-3225 or by telephoning one 
of the contacts listed below.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, Office of 
Protected Resources, NMFS, (301) 713-2055, ext 128.

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 plans 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 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 or a Geopulse 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 a 2-kilo-Joule (kJ) sparker system for shallow water and 
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-ft) 
hydrophone streamer is used for both multi-channel sources.
    (3) A Klein side-scan sonar for the environmental survey off Pt. 
Conception, CA.
    The high-resolution Huntec 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 system 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 unit is 205 dB re 1 microPa-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 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. 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 SPL for the Geopulse is 204 dB re 1 microPa-m (RMS), and 
its effective bandwidth is about 0.75 to 3.5 kHz. The firing rate is 
generally 0.5 to 1 sec. 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 
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 m (16.4 ft) behind the ship.
    Source characteristics of the SQUID 2000 provided by the 
manufacturer show an SPL of 209 dB re 1 microPa-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 in3) 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

[[Page 42543]]

USGS will use has an SPL of about 220 dB re 1 microPa-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 most odontocetes and pinnipeds (Richardson et al., 1995).
    The environmental survey off Pt. Conception will be accomplished 
with side-scan sonar surveying. The Klein 2000 side-scan 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 side-scan 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 side-scan system has an SPL of about 210 dB re 1 microPa-m 
(RMS). The output sound pulse is very short, with a time duration of 
less than 0.1 ms. The dual-frequency bandwidth of the outgoing signal 
is 100 kHz or 500 kHz.
    The work is planned for June 10-29, 2002. The primary work area (70 
percent of the time) is between Pt. Dume and offshore Gaviota, CA, 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). Some work might be 
attempted during transit between the two work areas.

Comments and Responses

    A notice of receipt of the application and proposed authorization 
was published on April 1, 2002 (67 FR 15360), and a 30-day public 
comment period was provided on the application and proposed 
authorization. Comments were received from the Marine Mammal Commission 
(MMC).
    Comment 1: The MMC believes that NMFS' preliminary determinations 
that the short-term impact of the proposed activities will result, at 
most in a temporary modification in behavior of certain species of 
marine mammals and that any behavioral modifications made by these 
species are expected to have no more than a negligible impact on the 
reproduction or survival of these species are reasonable, provided that 
NMFS is satisfied that the proposed monitoring and mitigation measures 
are adequate to detect and minimize disturbance to affected marine 
mammal species. In regard to the previous statement, the MMC notes that 
it is unclear whether night-time operations will be carried out in 
other than shallow water. If so, the MMC questions whether the planned 
night-time observations would be capable of assuring that the proposed 
activities have the least practicable adverse impact on marine mammals.
    Response: The USGS will be capable of conducting the monitoring 
program required under the IHA for this activity. As determined by the 
California Coastal Commission (CCC), the shutdown zones are 100 m (328 
ft) for the GI-airgun and 30 m (98 ft) for the other acoustic systems. 
The GI airgun will be used only during daylight hours. Monitoring these 
safety zones during daylight and night-time is practical.
    Comment 2: The MMC recommends that NMFS consult with the applicant 
to address this con cern, in order to ensure that any marine mammals 
approaching or entering the designated safety zone around the source(s) 
during night-time activities can be detected in time to stop operations 
to ensure that animals are not adversely affected.
    Response: See response to comment 1.
    Comment 3: The MMC notes that NMFS does not plan to require the 
shut down of the acoustic source if pinnipeds approach the source and 
enter the safety zone. The MMC recommends that NMFS require such 
approaches to be monitored and that the source be shut down if the 
animal(s) show signs of distress.
    Response: NMFS concurs and has made that recommendation a part of 
the IHA. Acoustic source transmissions will be suspended whenever the 
vessel approaches a pinniped and marine mammal behavior observations 
will be made during these periods. However, it should be understood 
that seals and sea lions will also actively approach a vessel while 
transmitting (the vessel itself moving forward at about 3-5 knots) from 
the side of the vessel or the stern, meaning that the animal is 
voluntarily approaching a noise source that is increasing in strength 
as the animal gets closer. Therefore, if a pinniped approaches the USGS 
vessel, the IHA requires the USGS to monitor the interaction to ensure 
the animal does not show signs of distress. If the pinniped(s) show 
obvious distress, the USGS is to suspend operations until the pinniped 
moves outside of the safety zone and to continue to conduct 
observations on effects on all pinnipeds after the acoustic source is 
again powered up.
    Comment 4: The MMC recommends that the applicant be required to 
include in the initial and final reports, the species and numbers of 
marine mammals observed approaching and entering the designated safety 
zones during both day and night.
    Response: NMFS concurs. The USGS will employ trained biologists to 
monitor marine mammals in and around the vicinity of the acoustic 
source and record behavioral activities. These observations will be 
provided to NMFS and the public under the reporting requirements 
contained in the IHA.

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 whale 
(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 
whale (Balaenoptera physalus), harbor seal (Phoca vitulina), elephant 
seal (Mirounga angustirostris), Steller sea lion (Eumetopias jubatus), 
California sea lion (Zalophus californianus), northern fur seal 
(Callorhinus ursinus) and sea otter (Enhydra lutris). General 
information on these species can be found in the USGS application and 
in Forney et al. (2001). Forney et al. (2001) 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 lead to some

[[Page 42544]]

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 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 microPa-m (RMS) or higher. 
For odontocetes and pinnipeds, activities should avoid, to the greatest 
extent practicable, exceeding a level of 190 dB re 1 microPa-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 1998. In 1999 however, 
the CCC limited this maximum sound-exposure level to 180 dB re 1 
microPa-m (RMS) for all marine mammals, including pinnipeds, within the 
coastal zone of California and as expected the CCC is requiring 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 cetaceans (e.g., 180 dB). As a result, although 
scientists have preliminarily established an SPL of 190 dB re 1 
microPa-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 an estimate of how close marine mammals can 
approach each sound source before it needs to be shut off. This 
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 1 microPa-m (RMS). The alternative

[[Page 42545]]

estimate of safe distance is proposed for operations in shallow water.
    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 microPa-m (RMS). In water deeper than 50 m (164 ft), 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 
and 205 dB Huntec boomers yield radii of 16 and 18 m (52.5 and 59 ft) 
respectively. The 210 dB Klein side-scan yields a safety radius of 32 m 
(105 ft), and the 220 dB GI gun yields a safety radius of 100 m (328 
ft). In its application, the USGS proposed that safety zones of 30 m 
(98 ft) around the boomers, minisparker, side-scan fish, and of 100 m 
(328 ft) around the airgun be used in water deeper than 50 m (164 ft). 
Although sound is expected to attenuate faster in shallow water, the 
CCC determined that the appropriate safety zones for this activity 
would be 100 m (328 ft) for the airgun and 50 m (164 ft) for the other 
sources.

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 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 4,792 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.

24-hour Seismic Operations

    The USGS requested that the IHA allow for 24-hour operations, 
specifically for the minisparker and/or boomers or side-scan. 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 2 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. Delays 
could require scheduling additional surveys in future years to complete 
the missed work. However, recently, the CCC determined that the GI-
airgun source could only be used during daylight hours. As a result, 
the IHA will prohibit use of the GI-airgun during night-time 
operations.

Mitigation

    Several mitigation measures to reduce the potential for marine 
mammal 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) around the GI-airgun source and 100 m (328 ft) 
around the other sound sources.
    (5) For other 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 side-
scan fish, and a zone of 100 m (328 ft) from the airgun.
    (6) For pinnipeds (seals and sealions): whenever the research 
vessel approaches a pinniped, a safety radius of 30 m (98.4 ft) around 
the boomer, minisparker, or side-scan sonar and 100 m (328 ft) around 
the GI-airgun will be maintained from the animal(s). However, if a 
pinniped (except for the Steller sea lion) approaches the towed airgun 
array during airgun transmissions, the USGS will not be required to 
shutdown the airguns, unless the animal(s) shows signs of distress. 
However, if a pinniped approaches the USGS vessel, the IHA requires the 
USGS to monitor the interaction to ensure the animal does not show 
signs of distress. If the pinniped(s) show obvious distress, the USGS 
is to suspend airgun operations until the pinniped moves outside of the 
safety zone and to continue to conduct

[[Page 42546]]

observations on effects on all pinnipeds after the airgun is again 
powered up. However, for Steller sea lions, these safety zones must be 
applied continuously.
    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, or if NMFS notifies the USGS, 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. Night-time operations in shallow water will 
be conducted with a spotlight to illuminate the radius of influence 
around the authorized acoustic sources 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.

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 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).

Consultation

    Under section 7 of the ESA, NMFS has completed consultation on the 
issuance of this IHA. NMFS has concluded that this action is unlikely 
to affect listed marine mammals because those species of whales that 
are listed under the ESA are rare in these waters, and are unlikely to 
be affected by these acoustic sources unless fairly close to the 
source. To ensure that listed marine mammals are not affected, NMFS is 
requiring the USGS to establish a safety zone of 250 m (820 ft) around 
the GI-airgun source and 100 m (328 ft) around the other sources with 
appropriate shutdown procedures imposed if a listed marine mammal 
enters or is about to enter the safety zone appropriate for the 
acoustic source.

Conclusions

    NMFS has determined that the short-term impact of collecting marine 
seismic reflection data to investigate the landslide and earthquake 
hazards off Southern California by the USGS during June, 2002 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 occur in 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 the affected species or stocks of 
marine mammals.
    In addition, no take by injury and/or death is anticipated and 
takes by harassment will be at the lowest level practicable due to 
incorporation of the mitigation measures mentioned previously. No known 
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.

Authorization

    As a result of these determinations, NMFS has issued 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 
to investigate the landslide and earthquake hazards off Southern 
California by the USGS during June, 2002, provided the above-mentioned 
mitigation,

[[Page 42547]]

monitoring, and reporting requirements are incorporated.

    Dated: June 13, 2002.
David Cottingham
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 02-15883 Filed 6-21-02; 8:45 am]
BILLING CODE 3510-22-S
Notices For
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Small Takes of Marine Mammals Incidental to Specified Activities; Seismic Reflection Data off Southern California

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