[Federal Register Volume 67, Number 26 (Thursday, February 7, 2002)]
[Notices]
[Pages 5792-5796]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-2998]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 010302E]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Seismic Hazard Investigations in Washington State

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice of receipt of application and proposed authorization for 
a small take exemption; request for comments.

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SUMMARY: NMFS has received a request from the 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 earthquake hazard in the Straits of Georgia region of 
Washington State. 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 April and late May, 2002.

DATES: Comments and information must be received no later than March 
11, 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 an Environmental Assessment (EA) 
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 Brent Norberg, Northwest 
Regional Office, NMFS, (206) 526-6733.

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 (a) has 
the potential to injure a marine mammal or marine mammal stock in 
the wild; or (b) 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

    In April and May, 2002, the USGS, in cooperation with the 
Geological Survey of Canada and the University of Victoria, will 
collect marine seismic reflection data to investigate the earthquake 
hazards in the Straits of Georgia. For approximately 2 to 4 days this 
research will be in U.S. waters and about 17 to 19 days will be in 
Canadian waters. Geological features around the Straits of Georgia that 
might produce earthquakes lie obscured beneath water, urban areas, 
forest, and thick glacial deposits. As a result, investigators must use 
sound waves that are produced by either single airguns or more usually 
an array of airguns to indirectly view these features. Because seismic 
noise from the proposed survey's airguns could potentially affect 
marine mammals due to disturbance by sound (i.e., acoustic

[[Page 5793]]

harassment), an incidental harassment authorization (IHA) under the 
MMPA is warranted.
    Throughout western Washington state and southwest British Columbia 
(BC), geological faults that might produce earthquakes lie hidden 
beneath the dense forest and the waters of Puget Sound and the Strait 
of Georgia. Although some faults are known from limited exposures on 
land and from marine seismic surveys, such as the Lummi Island and 
Outer Islands faults (see Figure 1 in the USGS application), more may 
have eluded detection in this little-studied area. Furthermore, the 
amount of recent (50,000 years) motion on these faults, if any, is 
unknown. Estimating the frequency and sizes of earthquakes on both the 
known and unknown faults is crucial to understanding the earthquake 
risk to the cities of Bellingham and Anacortes, WA to Vancouver and 
Victoria, BC and to the more rural parts of the region. For more 
detailed information on the geological faults in this area, please 
refer to the USGS application.
    Seismic reflection data will be collected during the period of 
April and May by the Canadian research vessel J. P. Tully. Seismic 
profiling will be done by towing a 600-m (1,968.5-ft) long hydrophone 
streamer for sensing and recording pressure changes from the airgun 
echos. The streamer will be towed at a depth of 5 m (16.4 ft). Near the 
forward end of the streamer, an airgun will be towed about 10 m (32.8 
ft) behind the ship at a depth of about 5 m (16.4 ft). The hydrophone 
streamer, which is connected to a computer recording system, will 
record echos coming from the strata beneath the sea bottom. These 
recordings will be computer-processed to create an image of the 
subsurface strata, including any faults that are crossed during the 
profiling. The seismic operation will operate 24 hours/day while in 
U.S. waters and will be traveling at a speed of 6 to 8 knots (6.9 to 
9.2 miles/hr; 11.1 to 14.8 km/hr).
    The sound source will be either a single, 120 inch\3\ airgun or, 
more likely, a small array of airguns consisting of two 40-
in3 and two 20-in3 guns being fired within 
several milliseconds (\1/1000\ second) of each other. The source will 
be chosen after tests at the beginning of the cruise. Either way, this 
sound source, as measured by the volume of the chamber, is only 2 
percent of the size of the airgun array used in the USGS survey 
conducted in 1998 in Puget Sound (see 63 FR 2213, January 14, 1998). 
Both of the USGS' potential sources will produce similar levels of 
sound pressure, which is estimated to be about 225 dB. An array of 
small airguns increases the frequency of the sound over that from a 
single gun, and an array better directs the sound downward. This array 
has been used previously in the inland waters of Canada (Reidel et al., 
1999), and the characteristics of this sound source have been measured 
(see Figure 3 in the USGS application).
    The airgun does not emit a prolonged sound source; rather, it emits 
an impulsive noise burst (10 milliseconds) with a peak-to-peak (P-P) 
sound pressure level (SPL) estimated to be 220 to 230 dB. The USGS' 
best estimate is that the source will have an SPL of about 225 dB. This 
compares to an estimated 240 dB SPL for the 6730 inch 3 
airgun array used in the 1998 Puget Sound seismic survey project 
(Fisher, 1997). This also compares with the continuous noise from 
freighters and other ship traffic in the area, which is estimated to be 
150 to 205 dB (Natural Resources Defense Council, 1998). The airgun 
will be fired almost continuously 3 to 6 times per minute.
    The frequency spectrum of the sound emission was measured when the 
array was used in a previous study (Reidel et al., 1999). The airgun's 
energy is concentrated below 200 Hz, with a rapid decrease in amplitude 
with increasing frequency between 200 and 400 Hz. Frequencies above 400 
Hz have amplitudes that are less than 10 percent of the lower 
frequencies. For purposes of later discussion, frequencies below 1,000 
Hz (1 kHz) are considered low frequency (LF).

Description of Habitat and Marine Mammals Affected by the Activity

    A description of the affected habitat and its associated marine 
mammals can be found in the USGS application and in several documents 
issued previously for acoustic research in Washington State waters 
(NMFS, 1996, 1997).

Marine Mammals

    The species of marine mammals that are likely to be present in the 
region of the Straits of Georgia include the harbor porpoise (Phocoena 
phocoena), killer whale (Orcinus orca), Dall's porpoise (Phocoenoides 
dalli), harbor seal (Phoca vitulina) California sea lion (Zalophus 
californianus) and elephant seal (Mirounga angustirostris) 
(Calambokidis and Baird, 1995). Additional species that are rare or 
only occasionally seen in the area at the time of the survey include: 
Pacific white-sided dolphin (Lagenorhynchus obliquidens), northern sea 
lion (Eumetopias jubatus), minke whale (Balaenoptera acutorostrata) 
humpback whale (Megaptera novaengliae) and gray whale (Eschrichtius 
robustus). However, because of the short duration of this project in 
waters under the jurisdiction of the United States, it is very unlikely 
that these latter species would be harassed, or injured as a result of 
conducting seismic surveys. These species include: Pacific white-sided 
dolphin, northern sea lion, minke whale, humpback whale, and gray 
whale.
    General information on the marine mammal species can be found in 
the USGS application and the previously mentioned documents prepared 
under the National Environmental Policy Act (NEPA). Information on 
marine mammal species in this area can also be found in Forney et al. 
(2000). The NEPA documents are available upon request (see ADDRESSES); 
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 specific information on marine 
mammal species.

Potential Effects of Seismic Surveys on Marine Mammals

Discussion

    Disturbance by seismic noise is the principal means of taking 
incidental to this activity. Vessel noise may provide a secondary 
source. Also, the physical presence of vessel(s) could also lead to 
some non-acoustic effects involving visual or other cues.
    The effects of underwater noise on marine mammals are highly 
variable, and can be categorized as follows (based on Richardson et 
al., 1995): (1) The noise 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 noise may be audible but not strong enough to elicit any overt 
behavioral response; (3) the noise 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 noise that 
is strong enough to be heard has the potential to

[[Page 5794]]

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 open-water seismic operations 
may be detectable some substantial distance away from the activity. Any 
sound that is detectable is (at least in theory) capable of eliciting a 
disturbance reaction by a marine mammal or masking a signal of 
comparable frequency. An incidental harassment take is presumed to 
occur when marine mammals in the vicinity of the seismic source (or 
vessel) show a significant behavioral response to the generated sounds 
or visual cues.
    High-intensity LF 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 seismic source pulses 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 an airgun array 
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. However, planned monitoring and mitigation 
measures (described later in this document) are designed to detect 
marine mammals occurring near the seismic array and to avoid, to the 
greatest extent practicable, exposing them to sound pulses that have 
any possibility of causing hearing damage.
    Two factors determine the effect of the airgun array on marine 
mammals: (1) The intensity of the sound, and (2) the frequency range of 
the sound. There is about a 16-dB difference between measuring the P-P 
sound pressure and the more commonly used root-mean-square (RMS) 
measurement of sound pressure on marine mammals (6 dB converts P-P to 
peak-to-zero values, and an additional 10 dB converts peak-to-zero to 
RMS values). These conversions mean that the USGS airgun array will be 
approximately equivalent to a source with a RMS sound pressure of about 
204 to 214 dB (relative to 1 micron Pa-m), with a best estimate being 
about 209 dB (RMS).
    The airgun sound spreads laterally in the water as the radius of 
the sound wave increases, resulting in a decrease in amplitude with 
distance of 20Log(R) or greater (R=distance in meters). Given this 
estimate of decay, a 230 dB (P-P) sound pressure decays to 180 dB (P-P) 
at a distance of about 300 m (984.3 ft) (see Figure 4 in the USGS 
application) and to 180 dB (RMS) at about 50 m (164 ft) from the 
source. Thus, the maximum range at which the USGS sound source could 
theoretically result in TTS is 50 m (164 ft).
    However, the frequency range of the airguns lies primarily outside 
the hearing range of most marine mammals. Data on hearing thresholds 
for odontocetes and pinnipeds show that the most sensitive hearing is 
in the 1,000- to 100,000-Hz frequency range (see Figure 5 of the USGS 
application; Richardson et al., 1995; Kastack and Schusterman, 1995). 
The USGS airgun source rapidly decreases in strength above 200 Hz, 
resulting in the source strength above 400 Hz being less than 10 
percent of the amplitude at lower frequencies. The USGS has estimated 
the SPL of its airgun source as a function of frequency. The P-P sound 
pressure is created by the sum of waves of all the frequencies emitted 
by the airguns, with each frequency contributing only a portion of the 
total sound. If the maximum P-P SPL is divided by the frequency 
spectrum of the airgun array, the amplitude of the individual frequency 
components can be estimated at several distances, as shown in Figure 5 
of the USGS application. The results indicate that the noise from any 
specific frequency emitted from the airgun array lies below the TTS of 
marine mammals at all distances (see Figure 5 of the USGS application).
    The latter estimate of the strength of the individual frequency 
components is an underestimate, however, because it assumes that all 
the frequencies are exactly in phase to produce the sound pulse. In 
reality, the system is not perfectly efficient as implied in this 
calculation, and the individual frequency components are somewhat 
larger than shown in Figure 4 of the USGS application. If it is assumed 
that the USGS source is about 70 percent efficient, the individual 
frequency components would be about 1.43 times what the USGS estimates 
assuming perfect efficiency. By this calculation, the sound levels from 
the airgun lie below the temporary hearing shift of most marine mammals 
at any distance greater than 50 m (164 ft)(USGS, 2001).
    The USGS proposes that the best estimate of the strength of the 
airgun source is the 209 dB (RMS) measure of sound pressure. Using this 
RMS measure, the ``annoyance'' or behavioral-response threshold is 
reached at a distance of 300 m (984.3 ft) from the airguns. This 
implies that animals 300 m (984.3 ft) from the USGS airguns will become 
annoyed and presumably will move away, but TTS would potentially not 
occur unless the USGS airguns were within 50 m (164 ft) of a marine 
mammal.

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:

[[Page 5795]]

    (1) Scheduling the survey for the period of April and May, when 
marine mammal abundance in the Straits of Georgia is low;
    (2) Having the vessel's speed between 6 and 8 knots to permit 
marine mammals that hear the ship and airgun noise to be able to move 
out of the area of the ship's track if they find the approaching vessel 
and accompanying noise annoying.
    (3) A safety zone of 100 m (328 ft) around the seismic aigruns will 
be established and the USGS will shut down the airgun operation if any 
marine mammal except seals enters the safety zone. The 100-m (328-ft) 
distance is double the 50-m (164-ft) estimate of the distance for TTS. 
This safety zone radius compares with a 100-m or 200-m (328- or 656-ft) 
safety radius for marine mammals that was used successfully in the 1998 
Puget Sound seismic experiment using much larger airguns (Fisher, 1997; 
Calambokidis and Osmek, 1998; Bain, 1998). The 1998 experiment had a 
500-m (1,640-ft) safety radius for gray, humpback and minke whales, 
which are not expected to be in the area during the short period of 
time (2-4 days) for surveys in U.S. waters. Given that the current USGS 
airgun source is only 2 percent of the size of the 1998 source as 
measured in chamber volume (120 inch \3\ versus 6730 inch \3\, the USGS 
believes that a 100-m (328-ft) safety radius is ample to ensure that no 
injury is caused to a marine mammal.
    (4) For pinnipeds (seals and sea lions), if the seismic vessel 
approaches a pinniped, a safety radius of 100 m (328 ft) will be 
maintained from the animal(s). However, if a pinniped approaches the 
towed airgun array during airgun transmissions, the USGS will not be 
required to shutdown the airguns. Experience indicates that pinnipeds 
will come from great distances to scrutinize seismic operations. Seals 
have been observed swimming within airgun bubbles, 10 m (33 ft) away 
from active arrays and, more recently, Canadian scientists, who were 
using a high-frequency seismic system that produced sound closer to 
pinniped hearing than will the USGS airgun array, describe how seals 
frequently approached close to the seismic source, presumably out of 
curiosity. Therefore, the above-mentioned mitigation plan has been 
proposed. In addition, the USGS will gather information on how often 
pinnipeds approach the airgun array on their own volition, and what 
effect the airguns appear to have on them.
    (5) To ensure no marine mammals are inadvertently harmed when data 
collection first begins or resumes after operations have ceased, the 
airguns will be turned on sequentially, so that peak power is achieved 
gradually to give marine mammals a chance to move away from the source.
    (6) Upon notification by a local stranding network that a marine 
mammal has been found dead within the waters of the Straits of Georgia 
or nearby U.S. waters when the array is operating within that body of 
water, NMFS will investigate the stranding to determine whether a 
reasonable chance exists that the USGS seismic survey project 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 must cease U.S. operations until procedures are altered to 
eliminate the potential for future deaths.

Monitoring

    To monitor the 100 m (328 ft) safety zone when in U.S. waters, the 
USGS proposes to have two observers, one on each side of the ship, 
specifically watching for marine mammals at all times that the airguns 
are operating. Members of the crew, specifically the ship's pilot, will 
also be instructed to immediately notify the observers if any marine 
mammals are sited. Observations will begin at least 10 minutes before 
airguns are turned on. The observers will be equipped with binoculars 
during the day and night-vision equipment during the night, both of 
which are believed adequate to monitor the 100-m (328-ft) safety zone 
while standing on the ship. The observers will order the airgun 
operations to cease if the vessel approaches within 100 m (328 ft) of a 
marine mammal.
    The objectives of the proposed monitoring program will be: To 
mitigate potential harassment of marine mammals, to document the number 
of animals of each species present in the vicinity of the sound 
transmissions, and to evaluate the reactions of marine mammals to these 
transmissions.
    It should be recognized that, at this time, the monitoring program 
may not be adequately funded to meet the requirements of the MMPA and 
therefore may need to be modified. In order for an IHA to be issued, 
monitoring will need to be conducted at a level which ensures that the 
activity will have no more than a negligible impact on marine mammal 
species or stocks.

Reporting

    The USGS will provide an initial report to NMFS within 120 days of 
the completion of the Straits of Georgia marine seismic 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.

NEPA

    In conjunction with a seismic survey project in Puget Sound in 
1998, NMFS completed an EA that addressed the impacts on the human 
environment from issuance of an authorization and the alternatives to 
that action. NMFS' analysis resulted in a Finding of No Significant 
Impact. This proposed seismic survey will operate in the same 
geographic area as the 1998 survey and as the seismic airgun sources 
used in this proposed action are significantly less intense. 
Accordingly, this proposed action qualifies for a categorical exclusion 
under NEPA. Therefore, a new EA will not be prepared. A copy of the 
1997 EA is available upon request (see ADDRESSES).

Preliminary Conclusions

    NMFS has preliminarily determined that the short-term impact of 
conducting a marine seismic survey in the Straits of Georgia will 
result, at worst, in a temporary modification in behavior by certain 
species of pinnipeds, and possibly some individual cetaceans. While 
behavioral modifications may 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.
    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 data in Straits of 
Georgia region of Washington State, provided the above-mentioned 
mitigation, monitoring, and reporting requirements are incorporated.

[[Page 5796]]

Information Solicited

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning this request (see ADDRESSES).

    Dated: January 31, 2002.
David Cottingham,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 02-2998 Filed 2-6-02; 8:45 am]
BILLING CODE 3510-22-P