[Federal Register Volume 69, Number 232 (Friday, December 3, 2004)]
[Notices]
[Pages 70236-70249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-26635]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 101204A]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Low-Energy Seismic Survey in the Southwest Pacific Ocean

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

ACTION: Notice of receipt of application and proposed incidental take 
authorization; request for comments.

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SUMMARY: NMFS has received an application from the Scripps Institution 
of Oceanography, (Scripps), a part of the University of California, for 
an Incidental Harassment Authorization (IHA) to take small numbers of 
marine mammals, by harassment, incidental to conducting oceanographic 
surveys in the southwestern Pacific Ocean (SWPO). Under the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an authorization to Scripps to incidentally take, by 
harassment, small numbers of several species of cetaceans for a limited 
period of time within the next year.

DATES: Comments and information must be received no later than January 
3, 2005.

ADDRESSES: Comments on the application should be addressed to Steve 
Leathery, Chief, Permits, Conservation and Education Division, Office 
of Protected Resources, National Marine Fisheries Service, 1315 East-
West Highway, Silver Spring, MD 20910-3225, or by telephoning the 
contact listed here. The mailbox address for providing email comments 
is <a href="/cdn-cgi/l/email-protection#5e0e0c6f706f6e6f6c6e6a1f1e30313f3f70393128"><span class="__cf_email__" data-cfemail="124240233c23222320222653527c7d73733c757d64">[email protected]</span></a>. Please include in the subject line of the e-
mail comment the following document identifier: 101204A. Comments sent 
via e-mail, including all attachments, must not exceed a 10-megabyte 
file size. A copy of the application containing a list of the 
references used in this document may be obtained by writing to this 
address or by telephoning the contact listed here and is also available 
at: http://www.nmfs.noaa.gov/prot_res/PR2/Small_Take/smalltake_info.htm#applications.

FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead, Office of 
Protected Resources, NMFS, (301) 713-2322, 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 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 that 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

[[Page 70237]]

species or stock through effects on annual rates of recruitment or 
survival.''
    Section 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. 
Except with respect to certain activities not pertinent here, 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 [Level A harassment]; 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 
[Level B harassment].
    Section 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 
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 October 6, 2004, NMFS received an application from Scripps for 
the taking, by harassment, of several species of marine mammals 
incidental to conducting a low-energy marine seismic survey program 
during early 2005 in the SWPO. The overall area within which the 
seismic survey will occur is located between approximately 25[deg] and 
50[deg]S, and between approximately 133[deg] and 162.5[deg]W. The 
survey will be conducted entirely in international waters. The purpose 
of the seismic survey is to collect the site survey data for a second 
Integrated Ocean Drilling Program (IODP) transect, to study the 
structure of the Eocene Pacific from the subtropics into the Southern 
Ocean. A future ocean-drilling program cruise (not currently scheduled) 
based on the data collected in the present program will better document 
and constrain the actual patterns of atmospheric and oceanic 
circulation on Earth at the time of extreme warmth in the early Eocene. 
Through the later ocean drilling program, it is anticipated that marine 
scientists will be able to (1) define the poleward extent of the sub-
tropical gyre, (2) establish the position of the polar front, (3) 
determine sea-surface temperatures and latitudinal temperature 
gradient, (4) determine the width and intensity of the high-
productivity zone associated with these oceanographic features, (5) 
characterize the water masses formed in the sub-polar region, (6) 
determine the nature of the zonal winds and how they relate to oceanic 
surface circulation, and (7) document the changes in these systems as 
climate evolves from the warm early Eocene to the cold Antarctic of the 
early Oligocene. As presently scheduled, the seismic survey will occur 
from approximately February 11, 2005 to March 21, 2005.

Description of the Activity

    The seismic survey will involve one vessel. The source vessel, the 
R/V Melville, will deploy a pair of low-energy Generator-Injector (GI) 
airguns as an energy source (each with a discharge volume of 45 in\3\), 
plus a 450-meter (m) (1476-ft) long, 48-channel, towed hydrophone 
streamer. As the airguns are towed along the survey lines, the 
receiving system will receive the returning acoustic signals. The 
survey program will consist of approximately 11,000 kilometer (km) 
(5940 nautical mile (nm)) of surveys, including turns. Water depths 
within the seismic survey area are 4000-5000 m (13,123-16,400 ft) with 
no strong topographic features. The GI guns will be operated en route 
between piston-coring sites, where bottom sediment cores will be 
collected. There will be additional operations associated with 
equipment testing, start-up, line changes, and repeat coverage of any 
areas where initial data quality is sub-standard.
    The energy to the airguns is compressed air supplied by compressors 
on board the source vessel. Seismic pulses will be emitted at intervals 
of 6-10 seconds. At a speed of 7 knots (13 km/h), the 6-10 s spacing 
corresponds to a shot interval of approximately 21.5-36 m (71-118 ft).
    The generator chamber of each GI gun, the one responsible for 
introducing the sound pulse into the ocean, is 45 in\3\. The larger 
(105 in\3\) injector chamber injects air into the previously-generated 
bubble to maintain its shape, and does not introduce more sound into 
the water. The two 45/105 in\3\ GI guns will be towed 8 m (26.2 ft) 
apart side by side, 21 m (68.9 ft) behind the Melville, at a depth of 2 
m (6.6 ft).

General-Injector Airguns

    Two GI-airguns will be used from the Melville during the proposed 
program. These 2 GI-airguns have a zero to peak (peak) source output of 
237 dB re 1 microPascal-m (7.2 bar-m) and a peak-to-peak (pk-pk) level 
of 243 dB (14.0 bar-m). However, these downward-directed source levels 
do not represent actual sound levels that can be measured at any 
location in the water. Rather, they represent the level that would be 
found 1 m (3.3 ft) from a hypothetical point source emitting the same 
total amount of sound as is emitted by the combined airguns in the 
airgun array. The actual received level at any location in the water 
near the airguns will not exceed the source level of the strongest 
individual source and actual levels experienced by any organism more 
than 1 m (3.3 ft) from any GI gun will be significantly lower.
    Further, the root mean square (rms) received levels that are used 
as impact criteria for marine mammals (see Richardson et al., 1995) are 
not directly comparable to these peak or pk-pk values that are normally 
used to characterize source levels of airgun arrays. The measurement 
units used to describe airgun sources, peak or pk-pk decibels, are 
always higher than the rms decibels referred to in biological 
literature. For example, a measured received level of 160 dB rms in the 
far field would typically correspond to a peak measurement of about 170 
to 172 dB, and to a pk-pk measurement of about 176 to 178 decibels, as 
measured for the same pulse received at the same location (Greene, 
1997; McCauley et al. 1998, 2000). The precise difference between rms 
and peak or pk-pk values depends on the frequency content and duration 
of the pulse, among other factors. However, the rms level is always 
lower than the peak or pk-pk level for an airgun-type source.
    The depth at which the sources are towed has a major impact on the 
maximum near-field output, because the energy output is constrained by 
ambient pressure. The normal tow depth of the sources to be used in 
this project is 2.0 m (6.6 ft), where the ambient pressure is 
approximately 3 decibars. This also limits output, as the 3 decibars of 
confining pressure cannot fully constrain the source output, with the 
result that there is loss of energy at the sea surface. Additional 
discussion of the characteristics of airgun pulses is provided in 
Scripps application and in previous Federal Register documents (see 69 
FR 31792 (June 7, 2004) or 69 FR 34996 (June 23, 2004)).
    Received sound levels have been modeled by L-DEO for two 105 in3 GI 
guns, but not for the two 45 in\3\ GI-guns, in relation to distance and 
direction from the airguns. The model does not allow for bottom 
interactions, and is therefore most directly applicable to deep water. 
Based on the modeling, estimates of the maximum distances from the GI 
guns where sound levels of 190, 180, 170, and 160 dB microPascal-m 
(rms) are predicted to be received are shown in Table 1. Because the 
model results are for the larger 105 in\3\ guns,

[[Page 70238]]

those distances are overestimates of the distances for the 45 in3 guns.

   TABLE 1. Distances to which sound levels 190, 180, 170, and 160 dB
  microPascal-m (rms) might be received from two 105 in\3\ GI airguns,
   similar to the two 45 in\3\ GI airguns that will be used during the
   seismic survey in the SW Pacific Ocean during February-March 2005.
  Distances are based on model results provided by Lamont-Doherty Earth
                          Observatory (L-DEO).
              Estimated Distances at Received Levels (m/ft)
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Water Depth >1000...............   190 dB   180 dB     170 dB     160 dB
                                    17/56   54/177    175/574   510/1673
------------------------------------------------------------------------

    Some empirical data concerning the 180-, and 160-dB distances have 
been acquired for several airgun configurations, including two GI-guns, 
based on measurements during an acoustic verification study conducted 
by L-DEO in the northern Gulf of Mexico from 27 May to 3 June 2003 
(Tolstoy et al., 2004). Although the results are limited, the data 
showed that water depth affected the radii around the airguns where the 
received level would be 180 dB re 1 microPa (rms), NMFS' current injury 
threshold safety criterion applicable to cetaceans (NMFS, 2000). 
Similar depth-related variation is likely in the 190-dB distances 
applicable to pinnipeds. Correction factors were developed and 
implemented for previous IHAs for activities with water depths less 
than 1000 m (3281 ft), however, the proposed airgun survey will occur 
in depths 4000-5000 m (13,123-16,400 ft), so correction factors are not 
necessary here since the L-DEO model has been shown to be result in 
more conservative impact zones than indicated by the empirical 
measurements. Therefore, the assumed 180- and 190-dB radii are 54 m 
(177 ft) and 17 m (56 ft), respectively. Considering that the 2 GI-
airgun array is towed 21 m (69 ft) behind the Melville and the vessel 
is 85 m (270 ft) long, the forward aspect of the 180-dB isopleth (lines 
of equal pressure) at its greatest depth will not exceed approximately 
the mid-ship line of the Melville. At the water surface, an animal 
would need to be between the vessel and the 450-m (1476 ft) long 
hydrophone streamer to be within the 180-dB isopleth.

Bathymetric Sonar and Sub-bottom Profiler

    In addition to the 2 GI-airguns, a multi-beam bathymetric sonar and 
a low-energy 3.5-kHz sub-bottom profiler will be used during the 
seismic profiling and continuously when underway.
    Sea Beam 2000 Multi-beam Sonar - The hull-mounted Sea Beam 2000 
sonar images the seafloor over a 120[deg]-wide swath to 4600 m (15092 
ft) under the vessel. In ``deep'' mode (400-1000 m (1312-3281 ft), it 
has a beam width of 2[deg], fore-and-aft, uses very short (7-20 msec) 
transmit pulses with a 2-22 s repetition rate and a 12.0 kHz frequency 
sweep. The maximum source level is 234 dB microPa (rms).
    Sub-bottom Profiler - The sub-bottom profiler is normally operated 
to provide information about the sedimentary features and the bottom 
topography that is simultaneously being mapped by the multi-beam sonar. 
The energy from the sub-bottom profiler is directed downward by a 3.5-
kHz transducer mounted in the hull of the Melville. The output varies 
with water depth from 50 watts in shallow water to 800 watts in deep 
water. Pulse interval is 1 second (s) but a common mode of operation is 
to broadcast five pulses at 1-s intervals followed by a 5-s pause. The 
beamwidth is approximately 30[deg] and is directed downward. Maximum 
source output is 204 dB re 1 microPa (800 watts) while normal source 
output is 200 dB re 1 microPa (500 watts). Pulse duration will be 4, 2, 
or 1 ms, and the bandwith of pulses will be 1.0 kHz, 0.5 kHz, or 0.25 
kHz, respectively.
    Although the sound levels have not been measured directly for the 
sub-bottom profiler used by the Melville, Burgess and Lawson (2000) 
measured sounds propagating more or less horizontally from a sub-bottom 
profiler similar to the Scripps unit with similar source output (i.e., 
205 dB re 1 microPa m). For that profiler, the 160- and 180-dB re 1 
microPa (rms) radii in the horizontal direction were estimated to be, 
respectively, near 20 m (66 ft) and 8 m (26 ft) from the source, as 
measured in 13 m (43 ft) water depth. The corresponding distances for 
an animal in the beam below the transducer would be greater, on the 
order of 180 m (591 ft) and 18 m (59 ft) respectively, assuming 
spherical spreading. Thus the received level for the Scripps sub-bottom 
profiler would be expected to decrease to 160 and 180 dB about 160 m 
(525 ft) and 16 m (52 ft) below the transducer, respectively, assuming 
spherical spreading. Corresponding distances in the horizontal plane 
would be lower, given the directionality of this source (30[deg] 
beamwidth) and the measurements of Burgess and Lawson (2000).

Characteristics of Airgun Pulses

    Discussion of the characteristics of airgun pulses was provided in 
several previous Federal Register documents (see 69 FR 31792 (June 7, 
2004) or 69 FR 34996 (June 23, 2004)) and is not repeated here. 
Reviewers are referred to those documents for additional information.

Description of Habitat and Marine Mammals Affected by the Activity

    A detailed description of the SWPO area and its associated marine 
mammals can be found in the Scripps application and a number of 
documents referenced in that application, and is not repeated here. 
Forty species of cetacean, including 31 odontocete (dolphins and small- 
and large-toothed whales) species and nine mysticete (baleen whales) 
species, are believed by scientists to occur in the southwest Pacific 
in the proposed seismic survey area. Table 2 in the Scripps application 
summarizes the habitat, occurrence, and regional population estimate 
for these species. A more detailed discussion of the following species 
is also provided in the application: Sperm whale (Physeter 
macrocephalus), pygmy and dwarf sperm whales (Kogia spp.), southern 
bottlenose whale (Hyperoodon planifrons), Arnoux's beaked whale 
(Berardius arnuxii), Cuvier's beaked whale (Ziphius cavirostris), 
Shepherd's beaked whale (Tasmacetus shepherdi), Mesoplodont beaked 
whales (Andrew's beaked whale (Mesoplodon bowdoini), Blainville's 
beaked whale (M. densirostris), gingko-toothed whale (M. ginkgodens), 
Gray's beaked whale (M. grayi), Hector's beaked whale (M. hectori), 
spade-toothed whale (M.

[[Page 70239]]

traversii), strap-toothed whale (M. layardii), melon-headed whale 
(Peponocephala electra), pygmy killer whale (Feresa attenuata), false 
killer whale (Pseudorca crassidens), killer whale (Orcinus orca), long-
finned pilot whale (Globicephala melas), short-finned pilot whale (G. 
macrorhynchus), rough-toothed dolphin (Steno bredanensis), bottlenose 
dolphin (Tursiops truncatus), pantropical spotted dolphin (Stenella 
attenuata), spinner dolphin (Stenella longirostris), striped dolphin 
(Stenella coeruleoalba), short-beaked common dolphin (Delphinus 
delphis), hourglass dolphin (Lagenorhynchus cruciger), Fraser's dolphin 
(Lagenodelphis hosei), Risso's dolphin (Grampus griseus), southern 
right whale dolphin (Lissodelphis peronii), spectacled porpoise 
(Phocoena dioptrica), humpback whale (Megaptera novaeangliae), southern 
right whale (Eubalaena australis), pygmy right whale (Caperea 
marginata), common minke whale (Balaenoptera acutorostrata), Antarctic 
minke whale (Balaenoptera borealis). Bryde's whale (Balaenoptera 
edeni), sei whale (Balaenoptera borealis), fin whale (Balaenoptera 
physalus) and blue whale (Balaenoptera musculus). Because the proposed 
survey area spans a wide range of latitudes (25-50[deg] S), tropical, 
temperate, and polar species are all likely to be found there. The 
survey area is all in deep-water habitat but is close to oceanic island 
(Society Islands, Australes Islands) habitats, so both coastal and 
oceanic species might be encountered. However, abundance and density 
estimates of cetaceans found there are provided for reference only, and 
are not necessarily the same as those that likely occur in the survey 
area.
    Five species of pinnipeds could potentially occur in the proposed 
seismic survey area: southern elephant seal (Mirounga leonina), leopard 
seal (Hydrurga leptonyx), crabeater seal (Lobodon carcinophagus), 
Antarctic fur seal (Arctocephalus gazella), and the sub-Antarctic fur 
seal (Arctocephalus tropicalis). All are likely to be rare, if they 
occur at all, as their normal distributions are south of the Scripps 
survey area. Outside the breeding season, however, they disperse widely 
in the open ocean (Boyd, 2002; King, 1982; Rogers, 2002). Only three 
species of pinniped are known to wander regularly into the area (SPREP, 
1999): the Antarctic fur seal, the sub-Antarctic fur seal, and the 
leopard seal. Leopard seals are seen are far north as the Cook Islands 
(Rogers, 2002).
    More detailed information on these species is contained in the 
Scripps application, which is available at: http://www.nmfs.noaa.gov/prot_res/PR2/Small_Take/smalltake_info.htm#applications.

Potential Effects on Marine Mammals

    The effects of 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 reactions of variable conspicuousness and 
variable relevance to the well being of the marine mammal; these can 
range from temporary alert responses to active avoidance reactions such 
as vacating an area at least until the noise event ceases;
    (4) Upon repeated exposure, a marine mammal may exhibit diminishing 
responsiveness (habituation), or disturbance effects may persist; the 
latter is most likely with sounds that are highly variable in 
characteristics, infrequent and unpredictable in occurrence, and 
associated with situations that a marine mammal perceives as a threat;
    (5) Any anthropogenic noise that is strong enough to be heard has 
the potential to reduce (mask) the ability of a marine mammal to hear 
natural sounds at similar frequencies, including calls from 
conspecifics, and underwater environmental sounds such as surf noise;
    (6) If mammals remain in an area because it is important for 
feeding, breeding or some other biologically important purpose even 
though there is chronic exposure to noise, it is possible that there 
could be noise-induced physiological stress; this might in turn have 
negative effects on the well-being or reproduction of the animals 
involved; and
    (7) Very strong sounds have the potential to cause temporary or 
permanent reduction in hearing sensitivity. In terrestrial mammals, and 
presumably marine mammals, received sound levels must far exceed the 
animal's hearing threshold for there to be any temporary threshold 
shift (TTS) in its hearing ability. For transient sounds, the sound 
level necessary to cause TTS is inversely related to the duration of 
the sound. Received sound levels must be even higher for there to be 
risk of permanent hearing impairment. 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.

Effects of Seismic Surveys on Marine Mammals

    The Scripps' application provides the following information on what 
is known about the effects on marine mammals of the types of seismic 
operations planned by Scripps. The types of effects considered here are 
(1) tolerance, (2) masking of natural sounds, (2) behavioral 
disturbance, and (3) potential hearing impairment and other non-
auditory physical effects (Richardson et al., 1995). Given the 
relatively small size of the airguns planned for the present project, 
its effects are anticipated to be considerably less than would be the 
case with a large array of airguns. Scripps and NMFS believe it is very 
unlikely that there would be any cases of temporary or especially 
permanent hearing impairment, or non-auditory physical effects. Also, 
behavioral disturbance is expected to be limited to distances less than 
500 m (1640 ft), the zone calculated for 160 dB or the onset of Level B 
harassment. Additional discussion on species-specific effects can be 
found in the Scripps application.

Tolerance

    Numerous studies (referenced in Scripps, 2004) have shown that 
pulsed sounds from airguns are often readily detectable in the water at 
distances of many kilometers, but that marine mammals at distances more 
than a few kilometers from operating seismic vessels often show no 
apparent response. That is often true even in cases when the pulsed 
sounds must be readily audible to the animals based on measured 
received levels and the hearing sensitivity of that mammal group. 
However, most measurements of airgun sounds that have been reported 
concerned sounds from larger arrays of airguns, whose sounds would be 
detectable farther away than that planned for use in the proposed 
survey. Although various baleen whales, toothed whales, and pinnipeds 
have been shown to react behaviorally to airgun pulses under some 
conditions, at other times mammals of all three types have shown no 
overt reactions. In general, pinnipeds and small odontocetes seem to be 
more tolerant of exposure to airgun pulses than are baleen whales. 
Given the relatively small and low-energy airgun source planned for use 
in this project, mammals are expected to tolerate being closer to this 
source than would be the

[[Page 70240]]

case for a larger airgun source typical of most seismic surveys.

Masking

    Masking effects of pulsed sounds (even from large arrays of 
airguns) on marine mammal calls and other natural sounds are expected 
to be limited (due in part to the small size of the GI airguns), 
although there are very few specific data on this. Given the small 
acoustic source planned for use in the SWPO, there is even less 
potential for masking of baleen or sperm whale calls during the present 
research than in most seismic surveys (Scripps, 2004). GI-airgun 
seismic sounds are short pulses generally occurring for less than 1 sec 
every 6-10 seconds or so. The 6-10 sec spacing corresponds to a shot 
interval of approximately 21.5-36 m (71-118 ft). Sounds from the multi-
beam sonar are very short pulses, occurring for 7-20 msec once every 2 
to 22 sec, depending on water depth.
    Some whales are known to continue calling in the presence of 
seismic pulses. Their calls can be heard between the seismic pulses 
(Richardson et al., 1986; McDonald et al., 1995, Greene et al., 1999). 
Although there has been one report that sperm whales cease calling when 
exposed to pulses from a very distant seismic ship (Bowles et al., 
1994), a recent study reports that sperm whales continued calling in 
the presence of seismic pulses (Madsen et al., 2002). Given the 
relatively small source planned for use during this survey, there is 
even less potential for masking of sperm whale calls during the present 
study than in most seismic surveys. Masking effects of seismic pulses 
are expected to be negligible in the case of the smaller odontocete 
cetaceans, given the intermittent nature of seismic pulses and the 
relatively low source level of the airguns to be used in the SWPO. 
Also, the sounds important to small odontocetes are predominantly at 
much higher frequencies than are airgun sounds.
    Most of the energy in the sound pulses emitted by airgun arrays is 
at low frequencies, with strongest spectrum levels below 200 Hz and 
considerably lower spectrum levels above 1000 Hz. These low frequencies 
are mainly used by mysticetes, but generally not by odontocetes or 
pinnipeds. An industrial sound source will reduce the effective 
communication or echolocation distance only if its frequency is close 
to that of the marine mammal signal. If little or no overlap occurs 
between the industrial noise and the frequencies used, as in the case 
of many marine mammals relative to airgun sounds, communication and 
echolocation are not expected to be disrupted. Furthermore, the 
discontinuous nature of seismic pulses makes significant masking 
effects unlikely even for mysticetes.
    A few cetaceans are known to increase the source levels of their 
calls in the presence of elevated sound levels, or possibly to shift 
their peak frequencies in response to strong sound signals (Dahlheim, 
1987; Au, 1993; Lesage et al., 1999; Terhune, 1999; as reviewed in 
Richardson et al., 1995). These studies involved exposure to other 
types of anthropogenic sounds, not seismic pulses, and it is not known 
whether these types of responses ever occur upon exposure to seismic 
sounds. If so, these adaptations, along with directional hearing, pre-
adaptation to tolerate some masking by natural sounds (Richardson et 
al., 1995) and the relatively low-power acoustic sources being used in 
this survey, would all reduce the importance of masking marine mammal 
vocalizations.

Disturbance by Seismic Surveys

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous dramatic changes in activities, and 
displacement. However, there are difficulties in defining which marine 
mammals should be counted as taken by harassment. For many species and 
situations, scientists do not have detailed information about their 
reactions to noise, including reactions to seismic (and sonar) pulses. 
Behavioral reactions of marine mammals to sound are difficult to 
predict. Reactions to sound, if any, depend on species, state of 
maturity, experience, current activity, reproductive state, time of 
day, and many other factors. If a marine mammal does react to an 
underwater sound by changing its behavior or moving a small distance, 
the impacts of the change may not rise to the level of a disruption of 
a behavioral pattern. However, if a sound source would displace marine 
mammals from an important feeding or breeding area, such a disturbance 
may constitute Level B harassment under the MMPA. Given the many 
uncertainties in predicting the quantity and types of impacts of noise 
on marine mammals, it is appropriate to resort to estimating how many 
mammals may be present within a particular distance of industrial 
activities or exposed to a particular level of industrial sound. With 
the possible exception of beaked whales, NMFS believes that this is a 
conservative approach and likely overestimates the numbers of marine 
mammals that are affected in some biologically important manner.
    The sound exposure criteria used to estimate how many marine 
mammals might be harassed behaviorally by the seismic survey are based 
on behavioral observations during studies of several species. However, 
information is lacking for many species. Detailed information on 
potential disturbance effects on baleen whales, toothed whales, and 
pinnipeds can be found in Scripps's SWPO application and its Appendix 
A.

Hearing Impairment and Other Physical Effects

    Temporary or permanent hearing impairment is a possibility when 
marine mammals are exposed to very strong sounds, but there has been no 
specific documentation of this for marine mammals exposed to airgun 
pulses. Current NMFS policy precautionarily sets impulsive sounds equal 
to or greater than 180 and 190 dB re 1 microPa (rms) as the exposure 
thresholds for onset of Level A harassment for cetaceans and pinnipeds, 
respectively (NMFS, 2000). Those criteria have been used in defining 
the safety (shut-down) radii for seismic surveys. However, those 
criteria were established before there were any data on the minimum 
received levels of sounds necessary to cause auditory impairment in 
marine mammals. As discussed in the Scripps application and summarized 
here,
    1. The 180 dB criterion for cetaceans is probably quite 
precautionary, i.e., lower than necessary to avoid TTS let alone 
permanent auditory injury, at least for delphinids.
    2. The minimum sound level necessary to cause permanent hearing 
impairment is higher, by a variable and generally unknown amount, than 
the level that induces barely-detectable TTS.
    3. The level associated with the onset of TTS is often considered 
to be a level below which there is no danger of permanent damage.
    Because of the small size of the 2 45 in\3\ GI-airguns, along with 
the planned monitoring and mitigation measures, there is little 
likelihood that any marine mammals will be exposed to sounds 
sufficiently strong to cause even the mildest (and reversible) form of 
hearing impairment. Several aspects of the planned monitoring and 
mitigation measures for this project are designed to detect marine 
mammals occurring near the 2 GI-airguns (and bathymetric sonar), and to 
avoid exposing them to sound pulses that might (at least in theory) 
cause hearing impairment. In addition, research and monitoring studies 
on gray whales, bowhead whales and other cetacean species indicate that

[[Page 70241]]

many cetaceans are likely to show some avoidance of the area with 
ongoing seismic operations. In these cases, the avoidance responses of 
the animals themselves will reduce or avoid the possibility of hearing 
impairment.
    Non-auditory physical effects may also occur in marine mammals 
exposed to strong underwater pulsed sound. Possible types of non-
auditory physiological effects or injuries that theoretically might 
occur in mammals close to a strong sound source include stress, 
neurological effects, bubble formation, resonance effects, and other 
types of organ or tissue damage. It is possible that some marine mammal 
species (i.e., beaked whales) may be especially susceptible to injury 
and/or stranding when exposed to strong pulsed sounds. However, Scripps 
and NMFS believe that it is especially unlikely that any of these non-
auditory effects would occur during the proposed survey given the small 
size of the acoustic sources, the brief duration of exposure of any 
given mammal, and the planned mitigation and monitoring measures. The 
following paragraphs discuss the possibility of TTS, permanent 
threshold shift (PTS), and non-auditory physical effects.

TTS

    TTS is the mildest form of hearing impairment that can occur during 
exposure to a strong sound (Kryter, 1985). When an animal experiences 
TTS, its hearing threshold rises and a sound must be stronger in order 
to be heard. TTS can last from minutes or hours to (in cases of strong 
TTS) days. Richardson et al. (1995) note that the magnitude of TTS 
depends on the level and duration of noise exposure, among other 
considerations. For sound exposures at or somewhat above the TTS 
threshold, hearing sensitivity recovers rapidly after exposure to the 
noise ends. Little data on sound levels and durations necessary to 
elicit mild TTS have been obtained for marine mammals.
    For toothed whales exposed to single short pulses, the TTS 
threshold appears to be, to a first approximation, a function of the 
energy content of the pulse (Finneran et al., 2002). Given the 
available data, the received level of a single seismic pulse might need 
to be on the order of 210 dB re 1 microPa rms (approx. 221 226 dB pk 
pk) in order to produce brief, mild TTS. Exposure to several seismic 
pulses at received levels near 200 205 dB (rms) might result in slight 
TTS in a small odontocete, assuming the TTS threshold is (to a first 
approximation) a function of the total received pulse energy (Finneran 
et al., 2002). Seismic pulses with received levels of 200 205 dB or 
more are usually restricted to a zone of no more than 100 m (328 ft) 
around a seismic vessel operating a large array of airguns. Because of 
the small airgun source planned for use during this project, such sound 
levels would be limited to distances within a few meters directly 
astern of the Melville.
    There are no data, direct or indirect, on levels or properties of 
sound that are required to induce TTS in any baleen whale. However, TTS 
is not expected to occur during this survey given the small size of the 
source limiting these sound pressure levels to the immediate proximity 
of the vessel, and the strong likelihood that baleen whales would avoid 
the approaching airguns (or vessel) before being exposed to levels high 
enough for there to be any possibility of TTS.
    TTS thresholds for pinnipeds exposed to brief pulses (single or 
multiple) have not been measured, although exposures up to 183 dB re 1 
microPa (rms) have been shown to be insufficient to induce TTS in 
California sea lions (Finneran et al., 2003). However, prolonged 
exposures show that some pinnipeds may incur TTS at somewhat lower 
received levels than do small odontocetes exposed for similar durations 
(Kastak et al., 1999; Ketten et al., 2001; Au et al., 2000). For this 
research cruise therefore, TTS is unlikely for pinnipeds.
    A marine mammal within a zone of less than 100 m (328 ft) around a 
typical large array of operating airguns might be exposed to a few 
seismic pulses with levels of [gteqt]205 dB, and possibly more pulses 
if the mammal moved with the seismic vessel. Also, around smaller 
arrays, such as the 2 GI-airgun array proposed for use during this 
survey, a marine mammal would need to be even closer to the source to 
be exposed to levels greater than or equal to 205 dB. However, as noted 
previously, most cetacean species tend to avoid operating airguns, 
although not all individuals do so. In addition, ramping up airgun 
arrays, which is now standard operational protocol for U.S. and some 
foreign seismic operations, should allow cetaceans to move away from 
the seismic source and to avoid being exposed to the full acoustic 
output of the airgun array. Even with a large airgun array, it is 
unlikely that these cetaceans would be exposed to airgun pulses at a 
sufficiently high level for a sufficiently long period to cause more 
than mild TTS, given the relative movement of the vessel and the marine 
mammal. However, with a large airgun array, TTS would be more likely in 
any odontocetes that bow-ride or otherwise linger near the airguns. 
While bow-riding, odontocetes would be at or above the surface, and 
thus not exposed to strong sound pulses given the pressure-release 
effect at the surface. However, bow-riding animals generally dive below 
the surface intermittently. If they did so while bow-riding near 
airguns, they would be exposed to strong sound pulses, possibly 
repeatedly. During this project, the anticipated 180-dB distance is 
less than 54 m (177 ft), the array is towed 21 m (69 ft) behind the 
Melville and the bow of the Melville will be 106 m (348 ft) ahead of 
the airguns and the 205-dB zone would be less than 50 m (165 ft). Thus, 
TTS would not be expected in the case of odontocetes bow riding during 
airgun operations and if some cetaceans did incur TTS through exposure 
to airgun sounds, it would very likely be a temporary and reversible 
phenomenon.
    Currently, NMFS believes that, to avoid Level A harassment, 
cetaceans should not be exposed to pulsed underwater noise at received 
levels exceeding 180 dB re 1 microPa (rms). The corresponding limit for 
pinnipeds has been set at 190 dB. The predicted 180- and 190-dB 
distances for the airgun arrays operated by Scripps during this 
activity are summarized in Table 1 in this document. These sound levels 
are not considered to be the levels at or above which TTS might occur. 
Rather, they are the received levels above which, in the view of a 
panel of bioacoustics specialists convened by NMFS (at a time before 
TTS measurements for marine mammals started to become available), one 
could not be certain that there would be no injurious effects, auditory 
or otherwise, to marine mammals. As noted here, TTS data that are now 
available imply that, at least for dolphins, TTS is unlikely to occur 
unless the dolphins are exposed to airgun pulses substantially stronger 
than 180 dB re 1 microPa (rms).
    It has also been shown that most whales tend to avoid ships and 
associated seismic operations. Thus, whales will likely not be exposed 
to such high levels of airgun sounds. Because of the slow ship speed, 
any whales close to the trackline could move away before the sounds 
become sufficiently strong for there to be any potential for hearing 
impairment. Therefore, there is little potential for whales being close 
enough to an array to experience TTS. In addition, as mentioned 
previously, ramping up the airgun array, which has become standard 
operational protocol for many seismic operators including Scripps, 
should allow cetaceans to move away

[[Page 70242]]

from the seismic source and to avoid being exposed to the full acoustic 
output of the GI airguns.

Permanent Threshold Shift (PTS)

    When PTS occurs there is physical damage to the sound receptors in 
the ear. In some cases there can be total or partial deafness, while in 
other cases the animal has an impaired ability to hear sounds in 
specific frequency ranges. Although there is no specific evidence that 
exposure to pulses of airgun sounds can cause PTS in any marine 
mammals, even with the largest airgun arrays, physical damage to a 
mammal's hearing apparatus can potentially occur if it is exposed to 
sound impulses that have very high peak pressures, especially if they 
have very short rise times (time required for sound pulse to reach peak 
pressure from the baseline pressure). Such damage can result in a 
permanent decrease in functional sensitivity of the hearing system at 
some or all frequencies.
    Single or occasional occurrences of mild TTS are not indicative of 
permanent auditory damage in terrestrial mammals. However, very 
prolonged exposure to sound strong enough to elicit TTS, or shorter-
term exposure to sound levels well above the TTS threshold, can cause 
PTS, at least in terrestrial mammals (Kryter, 1985). Relationships 
between TTS and PTS thresholds have not been studied in marine mammals 
but are assumed to be similar to those in humans and other terrestrial 
mammals. The low-to-moderate levels of TTS that have been induced in 
captive odontocetes and pinnipeds during recent controlled studies of 
TTS have been confirmed to be temporary, with no measurable residual 
PTS (Kastak et al., 1999; Schlundt et al., 2000; Finneran et al., 2002; 
Nachtigall et al., 2003). In terrestrial mammals, the received sound 
level from a single non-impulsive sound exposure must be far above the 
TTS threshold for any risk of permanent hearing damage (Kryter, 1994; 
Richardson et al., 1995). For impulse sounds with very rapid rise times 
(e.g., those associated with explosions or gunfire), a received level 
not greatly in excess of the TTS threshold may start to elicit PTS. 
Rise times for airgun pulses are rapid, but less rapid than for 
explosions.
    Some factors that contribute to onset of PTS are as follows: (1) 
exposure to single very intense noises, (2) repetitive exposure to 
intense sounds that individually cause TTS but not PTS, and (3) 
recurrent ear infections or (in captive animals) exposure to certain 
drugs.
    Cavanagh (2000) has reviewed the thresholds used to define TTS and 
PTS. Based on his review and SACLANT (1998), it is reasonable to assume 
that PTS might occur at a received sound level 20 dB or more above that 
which induces mild TTS. However, for PTS to occur at a received level 
only 20 dB above the TTS threshold, it is probable that the animal 
would have to be exposed to the strong sound for an extended period.
    Sound impulse duration, peak amplitude, rise time, and number of 
pulses are the main factors thought to determine the onset and extent 
of PTS. Based on existing data, Ketten (1994) has noted that the 
criteria for differentiating the sound pressure levels that result in 
PTS (or TTS) are location and species-specific. PTS effects may also be 
influenced strongly by the health of the receiver's ear.
    Given that marine mammals are unlikely to be exposed to received 
levels of seismic pulses that could cause TTS, it is highly unlikely 
that they would sustain permanent hearing impairment. If we assume that 
the TTS threshold for odontocetes for exposure to a series of seismic 
pulses may be on the order of 220 dB re 1 microPa (pk-pk) 
(approximately 204 dB re 1 microPa rms), then the PTS threshold might 
be about 240 dB re 1 microPa (pk-pk). In the units used by 
geophysicists, this is 10 bar-m. Such levels are found only in the 
immediate vicinity of the largest airguns (Richardson et al., 1995; 
Caldwell and Dragoset, 2000). However, it is very unlikely that an 
odontocete would remain within a few meters of a large airgun for 
sufficiently long to incur PTS. The TTS (and thus PTS) thresholds of 
baleen whales and pinnipeds may be lower, and thus may extend to a 
somewhat greater distance from the source. However, baleen whales 
generally avoid the immediate area around operating seismic vessels, so 
it is unlikely that a baleen whale could incur PTS from exposure to 
airgun pulses. Some pinnipeds do not show strong avoidance of operating 
airguns. In summary, it is highly unlikely that marine mammals could 
receive sounds strong enough (and over a sufficient period of time) to 
cause permanent hearing impairment during this project. In the proposed 
project marine mammals are unlikely to be exposed to received levels of 
seismic pulses strong enough to cause TTS, and because of the higher 
level of sound necessary to cause PTS, it is even less likely that PTS 
could occur. This is due to the fact that even levels immediately 
adjacent to the 2 GI-airguns may not be sufficient to induce PTS 
because the mammal would not be exposed to more than one strong pulse 
unless it swam alongside an airgun for a period of time.

Strandings and Mortality

    Marine mammals close to underwater detonations of high explosives 
can be killed or severely injured, and the auditory organs are 
especially susceptible to injury (Ketten et al., 1993; Ketten, 1995). 
Airgun pulses are less energetic and have slower rise times. While 
there is no documented evidence that airgun arrays can cause serious 
injury, death, or stranding, the association of mass strandings of 
beaked whales with naval exercises and, an L-DEO seismic survey in 2002 
have raised the possibility that beaked whales may be especially 
susceptible to injury and/or stranding when exposed to strong pulsed 
sounds. Information on recent beaked whale strandings may be found in 
Appendix A of the Scripps application and in several previous Federal 
Register documents (see 69 FR 31792 (June 7, 2004) or 69 FR 34996 (June 
23, 2004)).
    It is important to note that seismic pulses and mid-frequency sonar 
pulses are quite different. Sounds produced by the types of airgun 
arrays used to profile sub-sea geological structures are broadband with 
most of the energy below 1 kHz. Typical military mid-frequency sonars 
operate at frequencies of 2 to 10 kHz, generally with a relatively 
narrow bandwidth at any one time (though the center frequency may 
change over time). Because seismic and sonar sounds have considerably 
different characteristics and duty cycles, it is not appropriate to 
assume that there is a direct connection between the effects of 
military sonar and seismic surveys on marine mammals. However, evidence 
that sonar pulses can, in special circumstances, lead to physical 
damage and, indirectly, mortality suggests that caution is warranted 
when dealing with exposure of marine mammals to any high-intensity 
pulsed sound.
    In addition to the sonar-related strandings, there was a September, 
2002 stranding of two Cuvier's beaked whales in the Gulf of California 
(Mexico) when a seismic survey by the Ewing was underway in the general 
area (Malakoff, 2002). The airgun array in use during that project was 
the Ewing's 20-gun 8490-in\3\ array. This might be a first indication 
that seismic surveys can have effects, at least on beaked whales, 
similar to the suspected effects of naval sonars. However, the evidence 
linking the Gulf of California strandings to the seismic surveys is 
inconclusive, and to date is not based on any physical

[[Page 70243]]

evidence (Hogarth, 2002; Yoder, 2002). The ship was also operating its 
multi-beam bathymetric sonar at the same time but this sonar had much 
less potential than these naval sonars to affect beaked whales. 
Although the link between the Gulf of California strandings and the 
seismic (plus multi-beam sonar) survey is inconclusive, this plus the 
various incidents involving beaked whale strandings associated with 
naval exercises suggests a need for caution in conducting seismic 
surveys in areas occupied by beaked whales. However, the present 
project will involve a much smaller sound source than used in typical 
seismic surveys. Considering this and the proposed monitoring and 
mitigation measures, any possibility for strandings and mortality is 
expected to be eliminated.

Non-auditory Physiological Effects

    Possible types of non-auditory physiological effects or injuries 
that might theoretically occur in marine mammals exposed to strong 
underwater sound might include stress, neurological effects, bubble 
formation, resonance effects, and other types of organ or tissue 
damage. There is no evidence that any of these effects occur in marine 
mammals exposed to sound from airgun arrays (even large ones). However, 
there have been no direct studies of the potential for airgun pulses to 
elicit any of these effects. If any such effects do occur, they would 
probably be limited to unusual situations when animals might be exposed 
at close range for unusually long periods.
    It is doubtful that any single marine mammal would be exposed to 
strong seismic sounds for sufficiently long that significant 
physiological stress would develop. That is especially so in the case 
of the present project where the airguns are small, the ship's speed is 
relatively fast (7 knots or approximately 13 km/h), and for the most 
part the survey lines are widely spaced with little or no overlap.
    Gas-filled structures in marine animals have an inherent 
fundamental resonance frequency. If stimulated at that frequency, the 
ensuing resonance could cause damage to the animal. There may also be a 
possibility that high sound levels could cause bubble formation in the 
blood of diving mammals that in turn could cause an air embolism, 
tissue separation, and high, localized pressure in nervous tissue 
(Gisner (ed), 1999; Houser et al., 2001).
    A workshop (Gentry [ed.] 2002) was held to discuss whether the 
stranding of beaked whales in the Bahamas in 2000 (Balcomb and 
Claridge, 2001; NOAA and USN, 2001) might have been related to air 
cavity resonance or bubble formation in tissues caused by exposure to 
noise from naval sonar. A panel of experts concluded that resonance in 
air-filled structures was not likely to have caused this stranding. 
Among other reasons, the air spaces in marine mammals are too large to 
be susceptible to resonant frequencies emitted by mid- or low-frequency 
sonar; lung tissue damage has not been observed in any mass, multi-
species stranding of beaked whales; and the duration of sonar pings is 
likely too short to induce vibrations that could damage tissues (Gentry 
(ed.), 2002). Opinions were less conclusive about the possible role of 
gas (nitrogen) bubble formation/growth in the Bahamas stranding of 
beaked whales.
    Until recently, it was assumed that diving marine mammals are not 
subject to the bends or air embolism. However, a short paper concerning 
beaked whales stranded in the Canary Islands in 2002 suggests that 
cetaceans might be subject to decompression injury in some situations 
(Jepson et al., 2003). If so, that might occur if they ascend unusually 
quickly when exposed to aversive sounds. However, the interpretation 
that the effect was related to decompression injury is unproven 
(Piantadosi and Thalmann, 2004; Fern[aacute]ndez et al., 2004). Even if 
that effect can occur during exposure to mid-frequency sonar, there is 
no evidence that this type of effect occurs in response to low-
frequency airgun sounds. It is especially unlikely in the case of this 
project involving only two small GI-airguns.
    In summary, little is known about the potential for seismic survey 
sounds to cause either auditory impairment or other non-auditory 
physical effects in marine mammals. Available data suggest that such 
effects, if they occur at all, would be limited to short distances from 
the sound source. However, the available data do not allow for 
meaningful quantitative predictions of the numbers (if any) of marine 
mammals that might be affected in these ways. Marine mammals that show 
behavioral avoidance of seismic vessels, including most baleen whales, 
some odontocetes, and some pinnipeds, are unlikely to incur auditory 
impairment or other physical effects. Also, the planned mitigation and 
monitoring measures are expected to minimize any possibility of serious 
injury, mortality or strandings.

Possible Effects of Mid-frequency Sonar Signals

    A multi-beam bathymetric sonar (Sea Beam 2000, 12 kHz) and a sub-
bottom profiler will be operated from the source vessel essentially 
continuously during the planned survey. Details about these sonars were 
provided previously in this document.
    Navy sonars that have been linked to avoidance reactions and 
stranding of cetaceans generally (1) are more powerful than the Sea 
Beam 2000 sonar, (2) have a longer pulse duration, and (3) are directed 
close to horizontally (vs. downward for the Sea Beam 2000). The area of 
possible influence of the Sea Beam 2000 is much smaller-a narrow band 
oriented in the cross-track direction below the source vessel. Marine 
mammals that encounter the Sea Beam 2000 at close range are unlikely to 
be subjected to repeated pulses because of the narrow fore-aft width of 
the beam, and will receive only limited amounts of pulse energy because 
of the short pulses and vessel speed. Therefore, as harassment or 
injury from pulsed sound is a function of total energy received, the 
actual harassment or injury threshold for the bathymetric sonar signals 
(approximately 10 ms) would be at a much higher dB level than that for 
longer duration pulses such as seismic signals. As a result, NMFS 
believes that marine mammals are unlikely to be harassed or injured 
from the multi-beam sonar.

Masking by Mid-frequency Sonar Signals

    Marine mammal communications will not be masked appreciably by the 
multi-beam sonar signals or the sub-bottom profiler given the low duty 
cycle and directionality of the sonars and the brief period when an 
individual mammal is likely to be within its beam. Furthermore, in the 
case of baleen whales, the sonar signals from the Sea Beam 2000 sonar 
do not overlap with the predominant frequencies of the calls, which 
would avoid significant masking.
    For the sub-bottom profiler, marine mammal communications will not 
be masked appreciably because of their relatively low power output, low 
duty cycle, directionality (for the profiler), and the brief period 
when an individual mammal may be within the sonar's beam. In the case 
of most odonotocetes, the sonar signals from the profiler do not 
overlap with the predominant frequencies in their calls. In the case of 
mysticetes, the pulses from the pinger do not overlap with their 
predominant frequencies.

Behavioral Responses Resulting from Mid-Frequency Sonar Signals

    Behavioral reactions of free-ranging marine mammals to military and 
other sonars appear to vary by species and circumstance. Observed 
reactions have

[[Page 70244]]

included silencing and dispersal by sperm whales (Watkins et al., 
1985), increased vocalizations and no dispersal by pilot whales 
(Rendell and Gordon, 1999), and the previously-mentioned strandings by 
beaked whales. Also, Navy personnel have described observations of 
dolphins bow-riding adjacent to bow-mounted mid-frequency sonars during 
sonar transmissions. However, all of these observations are of limited 
relevance to the present situation. Pulse durations from these sonars 
were much longer than those of the Scripps multi-beam sonar, and a 
given mammal would have received many pulses from the naval sonars. 
During Scripps' operations, the individual pulses will be very short, 
and a given mammal would not receive many of the downward-directed 
pulses as the vessel passes by.
    Captive bottlenose dolphins and a white whale exhibited changes in 
behavior when exposed to 1-sec pulsed sounds at frequencies similar to 
those that will be emitted by the multi-beam sonar used by Scripps and 
to shorter broadband pulsed signals. Behavioral changes typically 
involved what appeared to be deliberate attempts to avoid the sound 
exposure (Schlundt et al., 2000; Finneran et al., 2002). The relevance 
of these data to free-ranging odontocetes is uncertain and in any case 
the test sounds were quite different in either duration or bandwidth as 
compared to those from a bathymetric sonar.
    Scripps and NMFS are not aware of any data on the reactions of 
pinnipeds to sonar sounds at frequencies similar to those of the 12.0 
kHz frequency of the Melville's multi-beam sonar. Based on observed 
pinniped responses to other types of pulsed sounds, and the likely 
brevity of exposure to the bathymetric sonar sounds, pinniped reactions 
are expected to be limited to startle or otherwise brief responses of 
no lasting consequences to the individual animals. The pulsed signals 
from the sub-bottom profiler are much weaker than those from the multi-
beam sonar and somewhat weaker than those from the 2 GI-airgun array. 
Therefore, significant behavioral responses are not expected.

Hearing Impairment and Other Physical Effects

    Given recent stranding events that have been associated with the 
operation of naval sonar, there is much concern that sonar noise can 
cause serious impacts to marine mammals (for discussion see Effects of 
Seismic Surveys on Marine Mammals). However, the multi-beam sonars 
proposed for use by Scripps are quite different than sonars used for 
navy operations. Pulse duration of the bathymetric sonars is very short 
relative to the naval sonars. Also, at any given location, an 
individual marine mammal would be in the beam of the multi-beam sonar 
for much less time given the generally downward orientation of the beam 
and its narrow fore-aft beam-width. (Navy sonars often use near-
horizontally-directed sound.) These factors would all reduce the sound 
energy received from the multi-beam sonar rather drastically relative 
to that from the sonars used by the Navy. Therefore, hearing impairment 
by multi-beam bathymetric sonar is unlikely.
    Source levels of the sub-bottom profiler are much lower than those 
of the airguns and the multi-beam sonar. Sound levels from a sub-bottom 
profiler similar to the one on the Melville were estimated to decrease 
to 180 dB re 1 microPa (rms) at 8 m (26 ft) horizontally from the 
source (Burgess and Lawson, 2000), and at approximately 18 m downward 
from the source. Furthermore, received levels of pulsed sounds that are 
necessary to cause temporary or especially permanent hearing impairment 
in marine mammals appear to be higher than 180 dB (see earlier 
discussion). Thus, it is unlikely that the sub-bottom profiler produces 
pulse levels strong enough to cause hearing impairment or other 
physical injuries even in an animal that is (briefly) in a position 
near the source.
    The sub-bottom profiler is usually operated simultaneously with 
other higher-power acoustic sources. Many marine mammals will move away 
in response to the approaching higher-power sources or the vessel 
itself before the mammals would be close enough for there to be any 
possibility of effects from the less intense sounds from the sub-bottom 
profiler. In the case of mammals that do not avoid the approaching 
vessel and its various sound sources, mitigation measures that would be 
applied to minimize effects of the higher-power sources would further 
reduce or eliminate any minor effects of the sub-bottom profiler.

Estimates of Take by Harassment for the ETPO Seismic Survey

    Although information contained in this document indicates that 
injury to marine mammals from seismic sounds occurs at sound pressure 
levels significantly higher than 180 and 190 dB, NMFS' current criteria 
for onset of Level A harassment of cetaceans and pinnipeds from impulse 
sound are, respectively, 180 and 190 re 1 microPa rms. The rms level of 
a seismic pulse is typically about 10 dB less than its peak level and 
about 16 dB less than its pk-pk level (Greene, 1997; McCauley et al., 
1998; 2000a). The criterion for Level B harassment onset is 160 dB.
    Given the proposed mitigation (see Mitigation later in this 
document), all anticipated takes involve a temporary change in behavior 
that may constitute Level B harassment. The proposed mitigation 
measures will minimize or eliminate the possibility of Level A 
harassment or mortality. Scripps has calculated the ``best estimates'' 
for the numbers of animals that could be taken by level B harassment 
during the proposed SWPO seismic survey using data on marine mammal 
density (numbers per unit area) and estimates of the size of the 
affected area, as shown in the predicted RMS radii table (see Table 1). 
Because there is very little information on marine mammal densities in 
the proposed survey area, densities were used from two of Longhurst's 
(1998) biogeographic provinces north of the survey area that are 
oceanographically similar to the two provinces in which most of the 
seismic activities will take place.
    These estimates are based on a consideration of the number of 
marine mammals that might be exposed to sound levels greater than 160 
dB, the criterion for the onset of Level B harassment, by operations 
with the 2 GI-gun array planned to be used for this project. The 
anticipated zone of influence of the multi-beam sonar and sub-bottom 
profiler are less than that for the airguns, so it is assumed that 
during simultaneous operations of these instruments that any marine 
mammals close enough to be affected by the multi-beam and sub-bottom 
profiler sonars would already be affected by the airguns. Therefore, no 
additional incidental takings are included for animals that might be 
affected by the multi-beam sonar. Given their characteristics 
(described previously), no Level B harassment takings are considered 
likely when the multi-beam and sub-bottom profiler are operating but 
the airguns are silent.
    Table 2 provides the best estimate of the numbers of each species 
that would be exposed to seismic sounds greater than 160 dB. A detailed 
description on the methodology used by Scripps to arrive at the 
estimates of Level B harassment takes that are provided in Table 2 can 
be found in Scripps's IHA application for the SWPO survey.
BILLING CODE 3510-22-S

[[Page 70245]]

[GRAPHIC] [TIFF OMITTED] TN03DE04.001

Conclusions

Effects on Cetaceans
    Strong avoidance reactions by several species of mysticetes to 
seismic vessels have been observed at ranges up to 6-8 km (3.2-4.3 nm) 
and occasionally as far as 20-30 km (10.8-16.2 nm) from the source 
vessel when large arrays have been used. However, reactions at the 
longer distances appear to be atypical of most species and situations, 
and to large arrays. Furthermore, if they are encountered, the numbers 
of mysticetes estimated to occur within the 160-dB isopleth in the 
survey area are expected to be low. In addition, the estimated numbers 
presented in Table 2 are considered overestimates of actual numbers for 
three primary reasons. First, because the survey is scheduled for the 
end of the austral summer, some of the mysticetes and some species of 
odontocetes are expected to be present

[[Page 70246]]

in feeding areas south of the survey area. Second, the estimated 160- 
and 170-dB radii used here are probably overestimates of the actual 
160- and 170-dB radii at deep-water sites (Tolstoy et al. 2004) such as 
the SWPO survey area. Third, Scripps plans to use smaller GI guns than 
those on which the radii are based.
    Odontocete reactions to seismic pulses, or at least the reactions 
of dolphins, are expected to extend to lesser distances than are those 
of mysticetes. Odontocete low-frequency hearing is less sensitive than 
that of mysticetes, and dolphins are often seen from seismic vessels. 
In fact, there are documented instances of dolphins approaching active 
seismic vessels. However, dolphins as well as some other types of 
odontocetes sometimes show avoidance responses and/or other changes in 
behavior when near operating seismic vessels.
    Taking into account the small size and the relatively low sound 
output of the 2 GI-airguns to be used, and the mitigation measures that 
are planned, effects on cetaceans are generally expected to be limited 
to avoidance of a very small area around the seismic operation and 
short-term changes in behavior, falling within the MMPA definition of 
Level B harassment. Furthermore, the estimated numbers of animals 
potentially exposed to sound levels sufficient to cause appreciable 
disturbance are very low percentages of the affected populations.
    Based on the 160-dB criterion, the best estimates of the numbers of 
individual cetaceans that may be exposed to sounds [gteqt]160 dB re 1 
microPa (rms) represent 0 to approximately 0.2 percent of the 
populations of each species that may be encountered in the survey area. 
The assumed population sizes used to calculate the percentages are 
presented in Table 2 of the Scripps application. For species listed as 
endangered under the ESA, the estimates are significantly less than 0.1 
percent of the SWPO population of sperm, humpback, sei, and fin whales; 
probably less than 0.1 percent of southern right whales; and 0.1 
percent of blue whales (Table 2). In the cases of mysticetes, beaked 
whales, and sperm whales, the potential reactions are expected to 
involve no more than small numbers (2-32) of individual cetaceans. The 
sperm whale is the endangered species that is most likely to be 
exposed, and their SWPO population is approximately 140,000 (data of 
Butterworth et al. 1994 with g(0) correction from Barlow (1999) 
applied).
    Larger numbers of delphinids may be affected by the proposed 
seismic study, but the population sizes of species likely to occur in 
the operating area are large, and the numbers potentially affected are 
small relative to the population sizes (see Table 2). The best estimate 
of number of individual delphinids that might be exposed to sounds 160 
dB re 1 microPa (rms) represents significantly less than 0.01 percent 
of the approximately 8,200,000 dolphins estimated to occur in the SWPO, 
and 0-0.2 percent of the populations of each species occurring there 
(Table 2).
    Mitigation measures such as controlled speed, course alteration, 
observers, ramp ups, and power downs or shut downs when marine mammals 
are seen within defined ranges should further reduce short-term 
reactions, and minimize any effects on hearing. In all cases, the 
effects are expected to be short-term, with no lasting biological 
consequence. In light of the type of take expected and the small 
percentages of affected stocks of cetaceans, the action is expected to 
have no more than a negligible impact on the affected species or stocks 
of cetaceans.

Effects on Pinnipeds

    Five pinniped species-the sub-Antarctic fur seal, Antarctic fur 
seal, crabeater seal, leopard seal, and southern elephant seal-may be 
encountered at the survey sites, but their distribution and numbers 
have not been documented in the proposed survey area. An estimated 22-
45 individuals of each species of seal may be exposed to airgun sounds 
with received levels [gteqt] 160 dB re 1 microPa (rms). The estimates 
of pinnipeds that may be exposed to received levels [gteqt] 160 dB are 
probably overestimates of the actual numbers that will be affected 
significantly. The proposed survey would have, at most, a short-term 
effect on their behavior and no long-term impacts on individual 
pinnipeds or their populations. Responses of pinnipeds to acoustic 
disturbance are variable, but usually quite limited. Effects are 
expected to be limited to short-term and localized behavioral changes 
falling within the MMPA definition of Level B harassment. As is the 
case for cetaceans, the short-term exposures to sounds from the two GI-
guns are not expected to result in any long-term consequences for the 
individuals or their populations and the activity is expected to have 
no more than a negligible impact on the affected species or stocks of 
pinnipeds.

Potential Effects on Habitat

    The proposed seismic survey will not result in any permanent impact 
on habitats used by marine mammals, or to the food sources they 
utilize. The main impact issue associated with the proposed activity 
will be temporarily elevated noise levels and the associated direct 
effects on marine mammals.
    One of the reasons for the adoption of airguns as the standard 
energy source for marine seismic surveys was that they (unlike the 
explosives used in the distant past) do not result in any appreciable 
fish kill. Various experimental studies showed that airgun discharges 
cause little or no fish kill, and that any injurious effects were 
generally limited to the water within a meter or so of an airgun. 
However, it has recently been found that injurious effects on captive 
fish, especially on fish hearing, may occur at somewhat greater 
distances than previously thought (McCauley et al., 2000a,b, 2002; 
2003). Even so, any injurious effects on fish would be limited to short 
distances from the source. Also, many of the fish that might otherwise 
be within the injury-zone are likely to be displaced from this region 
prior to the approach of the airguns through avoidance reactions to the 
passing seismic vessel or to the airgun sounds as received at distances 
beyond the injury radius.
    Fish often react to sounds, especially strong and/or intermittent 
sounds of low frequency. Sound pulses at received levels of 160 dB re 1 
microPa (peak) may cause subtle changes in behavior. Pulses at levels 
of 180 dB (peak) may cause noticeable changes in behavior (Chapman and 
Hawkins, 1969; Pearson et al., 1992; Skalski et al., 1992). It also 
appears that fish often habituate to repeated strong sounds rather 
rapidly, on time scales of minutes to an hour. However, the habituation 
does not endure, and resumption of the disturbing activity may again 
elicit disturbance responses from the same fish.
    Fish near the airguns are likely to dive or exhibit some other kind 
of behavioral response. This might have short-term impacts on the 
ability of cetaceans to feed near the survey area. However, only a 
small fraction of the available habitat would be ensonified at any 
given time, and fish species would return to their pre-disturbance 
behavior once the seismic activity ceased. Thus, the proposed surveys 
would have little impact on the abilities of marine mammals to feed in 
the area where seismic work is planned. Some of the fish that do not 
avoid the approaching airguns (probably a small number) may be subject 
to auditory or other injuries.
    Zooplankton that are very close to the source may react to the 
airgun's shock wave. These animals have an

[[Page 70247]]

exoskeleton and no air sacs; therefore, little or no mortality is 
expected. Many crustaceans can make sounds and some crustacea and other 
invertebrates have some type of sound receptor. However, the reactions 
of zooplankton to sound are not known. Some mysticetes feed on 
concentrations of zooplankton. A reaction by zooplankton to a seismic 
impulse would only be relevant to whales if it caused a concentration 
of zooplankton to scatter. Pressure changes of sufficient magnitude to 
cause this type of reaction would probably occur only very close to the 
source, so few zooplankton concentrations would be affected. Impacts on 
zooplankton behavior are predicted to be negligible, and this would 
translate into negligible impacts on feeding mysticetes.

Potential Effects on Subsistence Use of Marine Mammals

    There is no known legal subsistence hunting for marine mammals in 
the SWPO, so the proposed Scripps activities will not have any impact 
on the availability of these species or stocks for subsistence users.

Mitigation

    For the proposed seismic survey in the SWPO during February-March 
2005, Scripps will deploy 2-GI airguns as an energy source, with a 
total discharge volume of 90 in3. The energy from the airguns will be 
directed mostly downward. The directional nature of the airguns to be 
used in this project is an important mitigating factor. This 
directionality will result in reduced sound levels at any given 
horizontal distance as compared with the levels expected at that 
distance if the source were omnidirectional with the stated nominal 
source level. Also, the small size of these airguns is an inherent and 
important mitigation measure that will reduce the potential for effects 
relative to those that might occur with large airgun arrays. This 
measure is in conformance with NMFS encouraging seismic operators to 
use the lowest intensity airguns practical to accomplish research 
objectives.
    The following mitigation measures, as well as marine mammal visual 
monitoring (discussed later in this document), will be implemented for 
the subject seismic surveys: (1) Speed and course alteration (provided 
that they do not compromise operational safety requirements); (2) shut-
down procedures; and (3) ramp-up procedures. Because the safety radius 
for cetaceans is only 54 m (177 ft) the use of passive acoustics to 
detect vocalizing marine mammals is not warranted for this survey. 
Similarly, and because the Melville will be transiting a distance of 
approximately 11,000 km (5940 nm) during the survey period at a speed 
of approximately 7 knots, aerial and secondary vessel support is not 
warranted.

Speed and Course Alteration

    If a marine mammal is detected outside its respective safety zone 
(180 dB for cetaceans, 190 dB for pinnipeds) and, based on its position 
and the relative motion, is likely to enter the safety zone, the 
vessel's speed and/or direct course may, when practical and safe, be 
changed in a manner that also minimizes the effect to the planned 
science objectives. The marine mammal activities and movements relative 
to the seismic vessel will be closely monitored to ensure that the 
marine mammal does not approach within the safety zone. If the mammal 
appears likely to enter the safety zone, further mitigative actions 
will be taken (i.e., either further course alterations or shut-down of 
the airguns).

Shut-down Procedures

    If a marine mammal is detected outside the safety radius but is 
likely to enter the safety radius, and if the vessel's course and/or 
speed cannot be changed to avoid having the animal enter the safety 
radius, the airguns will be shut down before the animal is within the 
safety radius. Likewise, if a marine mammal is already within the 
safety radius when first detected, the airguns will be shut down 
immediately.
    Following a shut-down, airgun activity will not resume until the 
marine mammal has cleared the safety zone. The animal will be 
considered to have cleared the safety zone if it (1) is visually 
observed to have left the safety zone, or (2) has not been seen within 
the zone for 15 min in the case of small odontocetes and pinnipeds, or 
(3) has not been seen within the zone for 30 min in the case of 
mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf 
sperm, bottlenose and beaked whales.

Ramp-up Procedure

    A ``ramp-up'' procedure will be followed when the airguns begin 
operating after a period without airgun operations. The 2-GI guns will 
be added in sequence 5 minutes apart. During ramp-up procedures, the 
safety radius for the 2-GI guns will be maintained.
    During the day or night, ramp-up cannot begin from a shut-down 
unless the entire 180-dB safety radius has been visible for at least 30 
minutes prior to the ramp up (i.e., no ramp-up can begin in heavy fog 
or high sea states). During nighttime operations, if the entire safety 
radius is visible using either vessel lights or night-vision devices 
(NVDs), then start up of the airguns from a shut down may occur. 
Considering that the safety zone will be an area approximately from 
mid-ship sternward to the area of the hydrophone streamer and extending 
only about 46 m ( ft) beyond the vessel, NMFS believes that either deck 
lighting or NVDs will be capable of locating any marine mammal that 
might enter the safety zone at night.
    Comments on past IHAs raised the issue of prohibiting nighttime 
operations as a practical mitigation measure. However, this is not 
practicable due to cost considerations and ship time schedules. The 
daily cost to the Federal Government to operate vessels such as 
Melville is approximately $33,000-$35,000 /day (Ljunngren, pers. comm. 
May 28, 2003). If the vessels were prohibited from operating during 
nighttime, each trip could require an additional three to five days to 
complete, or up to $175,000 more, depending on average daylight at the 
time of work.
    If a seismic survey vessel is limited to daylight seismic 
operations, efficiency would also be much reduced. Without commenting 
specifically on how that would affect the present project, for seismic 
operators in general, a daylight-only requirement would be expected to 
result in one or more of the following outcomes: cancellation of 
potentially valuable seismic surveys; reduction in the total number of 
seismic cruises annually due to longer cruise durations; a need for 
additional vessels to conduct the seismic operations; or work conducted 
by non-U.S. operators or non-U.S. vessels when in waters not subject to 
U.S. law.

Marine Mammal Monitoring

    Scripps must have at least two visual observers on board the 
Melville, and at least one must be an experienced marine mammalsw 
observer that NMFS has approved in advance of the start of the PO 
cruise. These observers will be on duty in shifts of no longer than 4 
hours.
    The visual observers will monitor marine mammals and sea turtles 
near the seismic source vessel during all daytime airgun operations, 
during any nighttime start-ups of the airguns and at night. During 
daylight, vessel-based observers will watch for marine mammals and sea 
turtles near the seismic vessel during periods with shooting (including 
ramp-ups), and for 30 minutes prior to the planned start of airgun 
operations after a shut-down. NMFS has preliminarily determined that a 
monitoring requirement for

[[Page 70248]]

observers to be on watch at night whenever daytime monitoring resulted 
in one or more shut-down situations due to marine mammal presence is 
not warranted for this operation since the Melville will be transiting 
the area and not remaining in the area where this requirement would 
provide protection for marine mammals. With a ship speed of 7 knots, 
the Melville may be a number of miles from the marine mammal siting/
shut-down area by night-time.
    Use of multiple observers will increase the likelihood that marine 
mammals near the source vessel are detected. Scripps bridge personnel 
will also assist in detecting marine mammals and implementing 
mitigation requirements whenever possible (they will be given 
instruction on how to do so), especially during ongoing operations at 
night when the designated observers are on stand-by and not required to 
be on watch at all times. The observer(s) and bridge watch will watch 
for marine mammals from the highest practical vantage point on the 
vessel or from the stern of the vessel, whichever provides the greatest 
total visibility of the safety zone.
    In addition, biological observers are required to record biological 
information on marine mammals sighted outside the safety zone, but 
within the 160-dB isopleth. For this activity, the observer(s) will 
systematically scan the area around the vessel with Big Eyes 
binoculars, reticle binoculars (e.g., 7 X 50 Fujinon) and with the 
naked eye during the daytime. Laser range-finding binoculars (Leica 
L.F. 1200 laser rangefinder or equivalent) will be available to assist 
with distance estimation. The observers will be used to determine when 
a marine mammal or sea turtle is in or near the safety radii so that 
the required mitigation measures, such as course alteration and power-
down or shut-down, can be implemented. If the GI-airguns are shut down, 
observers will maintain watch to determine when the animal is outside 
the safety radius.
    Observers are not required to be on duty during ongoing seismic 
operations at night (although they may do so); bridge personnel will 
watch for marine mammals during this time and will call for the airguns 
to be shut-down if marine mammals are observed in or about to enter the 
safety radii. However, a biological observer must be on standby at 
night and available to assist the bridge watch if marine mammals are 
detected. If the airguns are ramped-up at night (see previous section), 
two marine mammal observers will monitor for marine mammals for 30 
minutes prior to ramp-up and during the ramp-up using either deck 
lighting or NVDs that will be available (ITT F500 Series Generation 3 
binocular image intensifier or equivalent).
    Taking into consideration the additional costs of prohibiting 
nighttime operations and the likely impact of the activity (including 
all mitigation and monitoring), NMFS has preliminarily determined that 
the proposed mitigation and monitoring ensures that the activity will 
have the least practicable impact on the affected species or stocks. 
Marine mammals will have sufficient notice of a vessel approaching with 
operating seismic airguns, thereby giving them an opportunity to avoid 
the approaching array; if ramp-up is required, two marine mammal 
observers will be required to monitor the safety radii using shipboard 
lighting or NVDs for at least 30 minutes before ramp-up begins and 
verify that no marine mammals are in or approaching the safety radii; 
ramp-up may not begin unless the entire safety radii are visible.

Reporting

    Scripps will submit a report to NMFS within 90 days after the end 
of the cruise, which is currently predicted to occur during February 
and March, 2004. The report will describe the operations that were 
conducted and the marine mammals that were detected. The report must 
provide full documentation of methods, results, and interpretation 
pertaining to all monitoring tasks. The report will summarize the dates 
and locations of seismic operations, marine mammal sightings (dates, 
times, locations, activities, associated seismic survey activities), 
and estimates of the amount and nature of potential take of marine 
mammals by harassment or in other ways.

Endangered Species Act (ESA)

    Under section 7 of the ESA, the National Science Foundation (NSF), 
the agency funding Scripps, has begun consultation on the proposed 
seismic survey. NMFS will also consult on the issuance of an IHA under 
section 101(a)(5)(D) of the MMPA for this activity. Consultation will 
be concluded prior to a determination on the issuance of an IHA.

National Environmental Policy Act (NEPA)

    The NSF has prepared an EA for the SWPO oceanographic surveys. NMFS 
is reviewing this EA and will either adopt it or prepare its own NEPA 
document before making a determination on the issuance of an IHA. A 
copy of the NSF EA for this activity is available upon request (see 
ADDRESSES).

Preliminary Conclusions

    NMFS has preliminarily determined that the impact of conducting the 
seismic survey in the SWPO off may result, at worst, in a temporary 
modification in behavior by certain species of marine mammals. This 
activity is expected to result in no more than a negligible impact on 
the affected species or stocks.
    For reasons stated previously in this document, this preliminary 
determination is supported by (1) the likelihood that, given sufficient 
notice through slow ship speed and ramp-up, marine mammals are expected 
to move away from a noise source that it is annoying prior to its 
becoming potentially injurious; (2) recent research that indicates that 
TTS is unlikely (at least in delphinids) until levels closer to 200-205 
dB re 1 microPa are reached rather than 180 dB re 1 microPa; (3) the 
fact that 200-205 dB isopleths would be well within a few dozen meters 
of the vessel because of the small acoustic source; and (4) the 
likelihood that marine mammal detection ability by trained observers is 
close to 100 percent during daytime and remains high at night to the 
distance from the seismic vessel to the 180-dB isopleth. As a result, 
no take by injury or death is anticipated, and the potential for 
temporary or permanent hearing impairment is very low and will be 
avoided through the incorporation of the proposed mitigation measures 
mentioned in this document.
    While the number of potential incidental harassment takes will 
depend on the distribution and abundance of marine mammals in the 
vicinity of the survey activity, the number of potential harassment 
takings is estimated to be small. In addition, the proposed seismic 
program will not interfere with any legal subsistence hunts, since 
seismic operations will not take place in subsistence whaling and 
sealing areas and will not affect marine mammals used for subsistence 
purposes.

Proposed Authorization

    NMFS proposes to issue an IHA to Scripps for conducting a 
oceanographic seismic survey in the SWPO, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. NMFS has preliminarily determined that the proposed 
activity would result in the harassment of small numbers of marine 
mammals; would have no more than a negligible impact on the affected 
marine mammal stocks; and would not have an unmitigable adverse impact 
on the

[[Page 70249]]

availability of species or stocks for subsistence uses.

Information Solicited

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

    Dated: November 26, 2004.
Laurie K. Allen,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 04-26635 Filed 12-2-04; 8:45 am]
BILLING CODE 3510-22-S


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