[Federal Register Volume 65, Number 60 (Tuesday, March 28, 2000)]
[Notices]
[Pages 16374-16379]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-7611]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D.022800B]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Marine Seismic-Reflection Data Collection in 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 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 in 
southern California waters. 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 afore- mentioned area for a 3-week period between May 
and July 2000.

DATES: Comments and information must be received no later than April 
27, 2000.

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 and a list of references used in 
this document may be obtained by writing to this address or by 
telephoning one of the contacts listed here.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, 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.) 
directs the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region if certain findings are 
made and either regulations are issued or, if the taking is limited to 
harassment, 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), will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses, and 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 now 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

    On January 24, 2000, NMFS received a request from the USGS for 
authorization to take small numbers of several species of marine 
mammals by harassment incidental to collecting marine seismic-
reflection data from waters off southern California. Seismic data will 
be collected during a 3-week period between May and July 2000, 
preferably June, to determine the source of the invasion of seawater 
into freshwater aquifers that are critical to the Los Angeles-San Pedro 
area water supply and to support studies of the regional landslide and 
earthquake hazards for people within the coastal cities between Santa 
Barbara and San Diego.

Background

    The USGS proposes to conduct a high-resolution seismic survey 
offshore from Southern California. For a 3-week period between May and 
July 1999, preferably in June, the USGS would like to collect seismic-
reflection data to investigate: (1) the intrusion of seawater into 
freshwater coastal aquifers that are critical to the water supply for 
people within the Los Angeles- San Pedro area and (2) the hazards posed 
by landslides, tsunamis, and potential earthquake faults in the 
nearshore region from Santa Barbara to San Diego. Both of these tasks 
are multi-year efforts that require high-resolution, seismic-reflection 
data using a minisparker acoustic source.
    Coastal Southern California is the most highly populated urban area 
along the U.S. Pacific coast with 30 percent of the California 
population (approximately 10 million people) living in Los Angeles 
County alone. The primary objectives of the USGS research are to 
provide information (1) to understand and help mitigate the intrusion 
of salt water into coastal aquifer systems resulting from ground-water 
overdraft and (2) to help mitigate the earthquake threat to this area. 
Data collected to address the salt water intrusion objective will be 
used to develop a hydrogeologic model for the region. This model will 
assist water managers (Water Replenishment District of Southern 
California and the Los Angeles County Department of Public Works) 
provide a safe and uncontaminated ground-water supply to the local 
population.
    Important geologic information that the USGS will derive from this 
project's seismic-reflection data concerns how earthquake deformation 
is distributed offshore; that is, where the active faults are and what 
the history of movement along them has been. This should improve 
understanding of the shifting pattern of deformation that occurred over 
both the long term (approximately the last 100,000 years) and short 
term (the last few thousand years). The USGS seeks to identify actively 
deforming structures that may constitute significant earthquake 
threats. The USGS also proposes to locate offshore landslides that 
might affect coastal areas. Not only major subsea landslides might 
affect the footings of coastal buildings, but also very large slides 
can

[[Page 16375]]

generate local tsunamis. These large sea waves can be generated by 
seafloor movement that is produced either by landslides or by 
earthquakes. Knowing where large slides have occurred offshore will 
help locate areas susceptible to wave inundation.
    Some faults that have produced earthquakes lie entirely offshore or 
extend into offshore areas where they can be studied using high-
resolution seismic-reflection techniques. An example is the Rose Canyon 
fault, which extends through the San Diego area, and is considered to 
be the primary earthquake threat. This fault extends northward from La 
Jolla, beneath the inner continental shelf, and appears again onshore 
in the Los Angeles area. This fault and others like it near shore could 
generate moderate (M5-6) to large (M6-7) earthquakes.
    Knowing the location and geometry of fault systems is critical to 
estimating the location and severity of ground shaking. Therefore, the 
results of this project will contribute to decisions involving land 
use, hazard zonation, insurance premiums, and building codes.
    The USGS emphasizes that the goal is not to predict earthquakes but 
rather to help determine what steps might be taken to minimize the 
devastation should a large earthquake occur. The regional earthquake 
threat is known to be high, and a major earthquake could adversely 
affect the well-being of a large number of people. In one example, 
earthquakes in the coastal ocean off southern California commonly 
result in large-scale submarine landslides, many of which could be 
capable of producing destructive tsunamis.
    The proposed work is in collaboration with scientists at the 
Southern California Earthquake Center, which analyzes faults and 
earthquakes in onshore regions, and with scientists at the Scripps 
Institute of Oceanography, who measure strain (incremental movement) on 
offshore faults.
    The USGS also wants to collect high-resolution seismic-reflection 
data to locate the sources and pathways of seawater that intrudes into 
freshwater aquifers below San Pedro. Ground water usage in the Los 
Angeles basin began in the mid-1800s. Today, more than 44,000 acre-feet 
of freshwater each year are extracted from the aquifers that underlie 
the West Coast Basin. Aggressive extraction of freshwater from coastal 
aquifers causes offshore salt water to flow toward areas of active 
pumping. To limit this salt-water intrusion, the Water Replenishment 
District and water purveyors in San Pedro are investing $2.7 million 
per year at the Dominguez Gap Barrier Project to inject freshwater 
underground to establish a zone of high water pressure in the aquifers 
near San Pedro and Long Beach. The resulting zone of high pressure 
forms a barrier between the invasive saltwater and the productive 
coastal aquifers.
    USGS scientists in San Diego are working with the Los Angeles 
County Department of Public Works and the Water Replenishment District 
to develop a ground-water simulation model to predict fluid flow below 
San Pedro and nearby parts of the Los Angeles Basin. This model will 
eventually be used in managing water resources. The accuracy of the 
present model, however, is
    compromised by a paucity of information about aquifer geometry and 
about other geologic factors that might affect fluid flow. Data 
collected by the USGS will be used to improve three-dimensional, fluid-
flow models to aid management of water resources.

Proposed Field Work

    Fieldwork described here will be the fourth geophysical survey on 
the west coast that the USGS has conducted under close supervision by 
marine-mammal biologists. In March 1998, the USGS used a large (6,500 
in3., 106 liters) airgun array in and around Puget Sound to 
study the regional earthquake hazard (see 63 FR 2213, January 14, 
1998). The USGS employed 12 biologists, who worked on two ships 
continuously to oversee the seismic- reflection operations. On several 
occasions the USGS shut off the acoustic sources when marine mammals 
entered safety zones that had been stipulated by NMFS, and when mammals 
left these zones, the USGS gradually ramped-up the array as required in 
its permit to avoid harming wildlife. Marine-mammal biologists reported 
that during the survey, no overt distress was evident among the dense 
marine-mammal population, and afterward no unexplained marine-mammal 
strandings occurred.
    In August 1998, the USGS surveyed offshore from southern 
California, using a small airgun (40 in3, 0.65 liters). Two 
marine-mammal biologists oversaw this activity. In June 1999, the USGS 
conducted the third survey to support study of aquifer contamination 
and earthquake hazards in southern California (see 64 FR 31548, June 
11, 1999). Three marine-mammal biologists provided oversight for this 
operation. The survey described in this document is proposed to be 
conducted with similar oversight.

Experimental Design

    Marine studies conducted by the USGS focus where saltwater 
intrusion into coastal aquifers is an active concern and where other 
kinds of natural hazards have their greatest potential impact on 
society. In southern California, USGS studies will focus on five chief 
geographic areas. First is the San Pedro shelf, offshore of the 
Dominguez Gap barrier project. Collecting data as close to shore as 
feasible is critically important in order to merge onshore and offshore 
geology in a manner that allows modeling the hydrologic flow through 
the system. With respect to the seismic-hazard issues in the offshore, 
the USGS' main priority (and second geographic area) is the coastal 
zone and continental shelf between Long Beach and San Diego, where much 
of the hazard appears to be associated with strike-slip faults such as 
the Newport-Inglewood and Palos Verdes faults. A critical component of 
the survey concerns the third geographic area, which lies farther 
offshore in the Santa Monica, San Pedro, and San Diego Trough deeps, 
where rapid sedimentation has left a more complete record, relative to 
shallow-water areas, that can be used to decipher earthquake history. 
The fourth area is the extension into the Santa Barbara Channel of 
major elements of onshore geology that cross the northern part of Santa 
Monica Bay and include several major known earthquake faults. The fifth 
area is the geologic boundary, marked generally by the Channel Islands, 
between the inner California Borderland (dominated by strike-slip 
faults) and the Santa Barbara Channel (dominated by compressional 
faults). This change in fault types is important to study because the 
degree of earthquake threat varies with fault type. The study proposed 
herein focuses on the three highest priority areas, which lie near 
shore between Los Angeles and San Diego.
    The seismic-reflection survey is planned to last 21 days. Based on 
experience collecting seismic-reflection data in this general area 
during 1998 and 1999, the USGS would prefer to conduct the 2000 survey 
in June. Because it will have to contract for a vessel from which to 
conduct the geophysical survey, the targeted study time frame is 
sometime within the May through July window. The basis for this 
decision is the USGS' desire to avoid the gray whale migrations and the 
peak arrival of other mysticetes during the later summer. An important 
part of the effort this summer will be to fill in gaps

[[Page 16376]]

caused by shutdowns and daylight-only operations during earlier 
surveys.
    The USGS has not yet determined the exact tracklines for the 
survey, but it does know the areas where minisparker use will be 
concentrated (see Fig. 3 in the application). Within the overall work 
area, the objective is to collect seismic-reflection data along a grid 
of lines that are about 2 km (1.07 nmi) apart. Data collected during 
the 1998 and 1999 surveys will be used to guide the planning for the 
proposed survey in order to minimize the number of survey lines that 
are required to adequately define the aquifer geometries and location 
of potential earthquake faults.
    The USGS proposes to use two seismic-reflection systems for data 
collection: (1) A 1.5 kilo-Joule (kJ) minisparker using a 200-m (656.2-
ft) long multichannel streamer, and (2) a low-power, high resolution 
deep-tow system. The potential effect on marine mammals is from the 
minisparker; mammals cannot become entangled in the streamer. The low-
powered, high-resolution seismic- reflection system, manufactured by 
Huntec, Ltd., will obtain detailed information about the very shallow 
geology. The seismic-reflection systems will be aboard a vessel owned 
by a private contractor or academic cooperator. Ship navigation will be 
accomplished using satellites of the Global Positioning System. The 
survey ship will be able to report accurate positions, which is 
important to mitigating the minisparker's effect on marine mammals and 
to analyzing what impact, if any, minisparker operation has on the 
environment.

The Seismic Sound Sources

    The primary sound source to be used during this survey will be a 
1.5 kJ sparker ``SQUID 2000'' minisparker system manufactured by 
Applied Acoustic Engineering, Inc. This minisparker includes eight 
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 20 meters (65.6 ft) behind the ship.
    Source characteristics of the SQUID 2000TM provided by 
the manufacturer show a sound-pressure level (SPL) of 209 dB re 1 
Pa-m root-mean-square (RMS). The amplitude spectrum of this 
pulse indicates that most of the sound energy lies between 150 Hz and 
1700 Hz (1.7 kHz), and the peak amplitude is at 900 Hz. The output 
sound pulse of the minisparker has a duration of about 0.8 milli-
seconds (ms). When operated at sea for the multichannel seismic-
reflection survey proposed herein, the minisparker will be discharged 
every 4 to 6 seconds.
    The second seismic source that will be used during this survey is a 
HuntecTM system, which generates underwater sound at higher 
frequencies than does the minisparker. The Huntec system uses 
electromagnetically driven plates to produce an acoustic pulse every 
0.5 seconds. This sound source is towed approximately 100 meters (328.1 
ft) behind the ship in water depths greater than 200 m (656.2 ft). In 
shallow water, such as the inner shelf, the sound source is towed 
within 5 m (16.4 ft) of the sea surface. The SPL for this source is 205 
dB re 1 Pa RMS. The frequencies of the main output sound are 
between 500 Hz and 8 kHz, with a peak amplitude at 4.5 kHz.

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 (Delphinus 
delphis), killer whale (Orcinus orca), Pacific white-sided dolphin 
(Lagenorhynchus obliquidens), northern right whale dolphin 
(Lissodelphis borealis), Risso's dolphin (Grampus griseus), pilot 
whales (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), 
and California sea lion (Zalophus californianus), northern fur seal 
(Callorhinus ursinus) and sea otters (Enhydra lutris). General 
information on these latter species can be found in the USGS 
application and in Forney et al. (1999) and Barlow et al. (1998, 1997). 
Please refer to these documents for information on the biology, 
distribution, and abundance of these species in southern California 
waters.

Potential Effects of Seismic Surveys on Marine Mammals

Discussion

    Seismic surveys are used to obtain data about stratigraphic 
sequences and rock formations up to several thousands of feet deep. 
These surveys are accomplished by transmitting sound waves into the 
earth, which are reflected off subsurface formations and recorded with 
detectors in the water column.
    Disturbance by seismic noise is the principal means of taking by 
this activity. Vessel noise may provide a secondary source. Also, the 
physical presence of vessel(s) could lead to some non-acoustic effects 
involving visual or other cues.
    Depending upon ambient conditions and the sensitivity of the 
receptor, underwater sounds produced by open-water seismic operations 
may be detectable some 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 of 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) react to the generated sounds or to visual cues.
    Seismic pulses are known to cause some species of whales, including 
gray 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 limits the extent of masking. Bowhead whales in Arctic 
waters, 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 seasons. 
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

[[Page 16377]]

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 co-located or very close to the 
seismic source would be at risk of permanent hearing impairment, 
temporary threshold shift (TTS) is a theoretical possibility for 
animals close to the minisparker. However, planned monitoring and 
mitigation measures (described later in this document) are designed to 
detect marine mammals occurring near the seismic source(s) and to 
avoid, to the greatest extent practicable, exposing them to sound 
pulses that have any possibility of causing TTS in hearing.

Maximum Sound-Exposure Levels for Marine Mammals

    The adverse effects of underwater sound on mammals have been 
documented for exposure times that last for tens of seconds or 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). While NMFS in the past considered that the maximum SPLs, from 
impulse sounds, to which marine mammals should be exposed are 180 dB re 
1 Pa-m RMS for mysticetes (baleen whales) and sperm whales, 
and 190 dB re 1 Pa-m RMS for odontocetes (toothed whales, 
dolphins and porpoises) and pinnipeds (seals and sea lions), recent 
workshops have recommended a more precautionary approach be taken and, 
accordingly, NMFS now recommends that odontocetes also be limited to an 
SPL no greater than 180 dB re 1 Pa-m RMS. However, based on 
statements and recommendations made at NMFS' Acoustic Criteria Workshop 
in 1998, NMFS has not increased its recommended safety zone for 
pinnipeds to this same level. In 1999, the California Coastal 
Commission (CCC) limited the maximum sound-exposure level to 180 dB re 
1 Pa-m RMS for all species of marine mammals.
    In its application, the USGS has provided two estimates of how 
close marine mammals can approach the minisparker source before it 
needs to be powered down. The first estimate follows the procedure 
required by the CCC in 1999, where underwater sound is assumed to 
attenuate with distance according to the equation 20log(Radius(R)), and 
the maximum SPL to which marine mammals can be exposed is 180 dB re 1 
Pa-m RMS. The alternative estimate of safe distance is 
proposed for operations limited to shallow water. In shallow water, 
sound from the minisparker will decay (attenuate) with distance more 
sharply than 20log(R) because some of the sound energy will exit the 
water and penetrate the sea floor when the minisparker source is 
physically close to the sea floor.
    In the deeper water (greater than 50 m (164 ft)) areas of the 
proposed survey, the safety zone for the minisparker 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. For a 20log(R) sound attenuation, the 
safety zone for a 209 dB RMS source has a radius of about 30 m (98 ft).
    Much of that part of the proposed 2000 survey that focuses on 
saltwater intrusion of coastal aquifers will be conducted close to 
shore, where water is shallow. In such areas, underwater sound commonly 
attenuates more sharply than 20log(R) because sound exits the water 
layer and penetrates into the substrate. In 1999, the USGS measured a 
sound attenuation of 27log(R) in shallow water off southern California. 
Therefore, the USGS proposes that for inshore areas, underwater sound 
will attenuate approximately like 25log(R), which for inshore areas 
would yield a safety zone with a radius of 15 m (49.2 ft). Because of 
this short radius of the safety zone in shallow water, the USGS 
proposes that the minisparker can be used at night, using spotlights to 
illuminate the safety zone around the tow sled.

Estimated Number of Potential Harassments of Marine Mammals

    Based on estimated marine mammal populations within the survey area 
(Calambokidis and Francis, 1994) and on the number of individuals that 
were observed during the 1998 and 1999 seismic surveys, the USGS 
estimates that up to 50 blue whales, 5 killer whales, 10 minke whales, 
10 sea otters, 50 humpback whales, 50 northern sea lions, 100 northern 
fur seals, 100 northern elephant seals, 100 Dall's porpoise, 100 
Risso's dolphins, 100 northern right-whale dolphins, 100-200 Pacific 
white-sided dolphins, 100 bottlenosed dolphins, 200 California sea 
lions, 200 Pacific harbor seals, and 10,000-12,000 common dolphins may 
be harassed incidental to the USGS survey. No marine mammals will be 
seriously injured or killed as a result of the survey.

Proposed Mitigation of Potential Environmental Impact

    To avoid potential Level A harassment (i.e., injury) of marine 
mammals, safety zones will be established and monitored continuously by 
biologists, and the USGS will shut off the seismic source whenever the 
ship and a marine mammal converge closer than the previously mentioned 
safety distance.
    For gray, fin, blue and humpback whales, the marine mammal species 
near the survey area that are considered to be most sensitive to the 
frequency and intensity of the sound source, and for odontocetes, even 
with their lower sensitivity to the low frequency sound that will be 
emitted by the minisparker, minisparker operations will cease when 
members of these species approach within 30 m (98 ft) of the sound 
source when operating in deep water and 15 m (49.2 ft) when in shallow 
water as mentioned previously.
    For pinnipeds (seals and sea lions), if the research vessel 
approaches a pinniped, a safety radius of 30 m (98 ft) around the 
seismic source when operating in deep water and 15 m (49.2 ft) when in 
shallow water will be maintained. However, if a pinniped approaches the 
towed minisparker source, NMFS proposes that it will not require the 
USGS to shutdown the minisparker, but will require the USGS to monitor 
the interaction to ensure the animal does not show signs of distress. 
Experience indicates that pinnipeds will come from great distances to 
inspect seismic operations. Seals have been observed swimming within 
airgun bubbles, 10 m (33 ft) away from active arrays, apparently 
unaffected. Although minisparker oprations will be terminated if the 
pinnipeds show obvious distress, the USGS will conduct observations on 
effects the minisparker may have on the animals.
    The USGS plans to have marine biologists aboard the ship who will 
have the authority to stop the minisparker operations when a marine 
mammal enters the safety zone. If observations are made that one or 
more marine mammals of any species are attempting to beach themselves 
when the source is operating in the vicinity of the beaching, the 
minisparker will be immediately shut off and NMFS contacted.
    During seismic-reflection surveying, the ship's speed will only be 
4 to 5 knots, so that when the minisparker is being discharged, nearby 
marine mammals, if they hear the low frequency noise, will have gradual 
warning of the vessel's approach and can move away if disturbed. 
Finally, NMFS will coordinate with the local stranding network to 
determine whether strandings can be related to the seismic operation. 
If NMFS determines, based upon a necropsy of the animal(s), that the 
death was likely due to exposure to the minisparker, the survey shall 
cease

[[Page 16378]]

until procedures are altered to eliminate the potential for future 
deaths.
    Operating less than 24 hours each day incurs substantially 
increased cost for the leased ship, which the USGS states that it 
cannot afford. The ship schedule provides a narrow time window for this 
project; other experiments are already scheduled to precede and follow 
this one and for that reason, the USGS cannot arbitrarily extend the 
survey time. Thus, the USGS does not propose as a mitigation measure 
shutting down in dark or during periods of poor visibility. The 2000 
survey will require only three weeks, and it will be spread out 
geographically from Los Angeles to San Diego, so no single area will 
experience long-term activity. In the view of the USGS, the best course 
is to complete the experiment as expeditiously as possible. For these 
reasons, the USGS has requested that the Incidental Harassment 
Authorization (IHA) allow 24-hour operations, specifically at night and 
limiting surveys during this time to shallow water.

Monitoring and Reporting

    Monitoring marine mammals while the minisparker is active will be 
conducted 24 hours each day. Trained marine mammal observers will be 
aboard the seismic vessel to mitigate the potential environmental 
impact from minisparker use and to gather data on the species, number, 
and reaction of marine mammals to the minisparker. During daylight, 
observers will use 7x50 binoculars with internal compasses and 
reticules to record the horizontal and vertical angle to sighted 
mammals. Night-time operations will be conducted with a spotlight to 
illuminate the safety zone around the minisparker tow sled. Monitoring 
data to be recorded during minisparker operations include the name of 
the observer on duty, and weather conditions (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 off the minisparker whenever a marine mammal enters 
the safety zone.

Possible Modifications or Alternatives to the Proposed Survey

    The instructions for this permit request stipulate that the USGS 
consider alternatives to the proposed experiment. Options to change the 
activity are limited, but for the proposed survey, the USGS has changed 
from using an airgun source as used in prior surveys to a minisparker 
in order to reduce the probability for the harassment of marine mammals 
and to be able to operate within nearshore areas.
    To abandon this study altogether is a poor option. The USGS has 
described the societal relevance of this project as it would improve 
understanding of fluid movement in coastal aquifers and how to stem the 
intrusion of salt water into them. Another facet of this study is to 
help scientists understand the regional earthquake hazard that, in 
turn, will aid city planners in establishing building codes. If the 
project was canceled, such information would be unavailable.
    The seismic-source strength cannot be reduced further in an attempt 
to limit the potential environmental impact. The proposed minisparker 
is already smaller than any source the USGS has previously used for 
these kinds of geophysical surveys, and the problem with this option is 
that the USGS cannot significantly reduce the source strength without 
jeopardizing the success of this survey. This judgment is based on 
USGS' decades-long experience with seismic-reflection surveys, but 
especially on the 1998 survey that was conducted in the same general 
area as outlined here. If the USGS were to reduce the sound-source size 
and then fail to obtain the required information, another survey would 
need to be conducted, and this would have the potential to increase 
impact on marine mammals.
    This project could be carried out at some other time of year, and 
the USGS is open to suggestions. The USGS talked with biologists to 
find out the best time for the project to be conducted. The USGS wants 
to avoid the gray whale migrations and the mid-summer arrival of other 
mysticete species because, while these species remain mostly in the 
area of the Channel Islands, some individuals venture closer to the 
mainland. An important consideration in deciding the most appropriate 
time of the year is that biologists can best prevent harm to mammals 
when daylight is long, that is, near the solstice.

Reporting

    The USGS will contract with qualified marine-mammal observers to 
provide an initial report to NMFS within 160 days of the completion of 
the 2000 phase of the marine seismic 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 2000 phase of the marine seismic 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.

Conclusions

    NMFS has preliminarily determined that the short-term impact of 
conducting marine seismic-reflection data in offshore southern 
California will result, at worst, in a temporary modification in 
behavior by certain species of pinnipeds and cetaceans. While 
behavioral modifications may be made by certain species of marine 
mammals to avoid the resultant noise from the minisparker, this 
behavioral change is expected to have a negligible impact on the 
animals.
    In addition, no take by injury and/or death is anticipated, and 
takes will be at the lowest level practicable due to the incorporation 
of the mitigation measures previously mentioned. 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.

Proposed Authorization

    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 off southern 
California, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated. NMFS has preliminarily 
determined that the proposed activities would result in the harassment 
of only small numbers of each of several species of marine mammals and 
will have no more than a negligible impact on these marine mammal 
stocks.

Information Solicited

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


[[Page 16379]]


    Dated: March 22, 2000.
Donald R. Knowles,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 00-7611 Filed 3-27-00; 8:45 am]
BILLING CODE 3510-22-F