[Federal Register Volume 68, Number 241 (Tuesday, December 16, 2003)]
[Notices]
[Pages 70000-70005]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-30922]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 111403B]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Oceanographic Surveys off the Northern Yucatan Peninsula in the Gulf of 
Mexico

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 Lamont-Doherty Earth 
Observatory (LDEO), a part of Columbia University, for an Incidental 
Harassment Authorization (IHA) to take small numbers of marine mammals, 
by harassment, incidental to conducting oceanographic surveys off the 
northern Yucatan Peninsula in the Gulf of Mexico. Under the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an authorization to LDEO to incidentally take, by 
harassment, small numbers of several species of cetaceans and pinnipeds 
for a limited period of time within the next year.

DATES: Comments and information must be received no later than January 
15, 2004.

ADDRESSES: Comments on the application should be addressed to P. 
Michael Payne, Chief, Marine Mammal Conservation 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. 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
Comments cannot be accepted if submitted via e-mail or the Internet.

FOR FURTHER INFORMATION CONTACT: Kimberly Skrupky, Office of Protected 
Resources, NMFS, (301) 713-2322, ext 163.

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 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. 
Under section 3(18)(A), the MMPA defines ``harassment'' as:
    any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild; or (ii) has the potential to disturb a marine mammal or marine 
mammal stock in the wild by causing disruption of behavioral 
patterns, including, but not limited to, migration, breathing, 
nursing, breeding, feeding, or sheltering.
    The term ``Level A harassment'' means harassment described in 
subparagraph (A)(i). The term ``Level B harassment'' means harassment 
described in subparagraph (A)(ii).
    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

[[Page 70001]]

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 8, 2003, NMFS received an application from LDEO for the 
taking, by harassment, of several species of marine mammals incidental 
to conducting a seismic survey program. As presently scheduled, a 
seismic survey will be conducted in the Gulf of Mexico off the northern 
Yucatan Peninsula. The Gulf of Mexico research cruise will be off the 
coast of the northern Yucatan Peninsula in an area extending between 
21[deg] to 22.5[deg] N and 88[deg] to 91[deg] W from March 7, 2004 to 
April 4, 2004. The operations will partly take place in the Exclusive 
Economic Zone (EEZ) of Mexico.
    The purpose of the project is to study the Chicxulub Crater. The 
Chicxulub Crater was formed 65 million years ago when a massive meteor 
crashed into the Yucatan Peninsula of Mexico leaving behind the crater 
with a diameter of about 150 km (93 mi). The well-known massive 
extinction event at the Cretaceous-Tertiary (K-T) boundary appears to 
have been caused, at least in part, by this impact. It is also the only 
large terrestrial impact crater with a well preserved topographic peak 
ring. The Chicxulub Crater is uniquely suited for a seismic 
investigation into the deformation mechanisms of large diameter impacts 
in general and the physical parameters of the K-T impact in particular. 
The goals are to: (1) Determine the direction of approach and angle of 
the Chicxulub impact through the collaborative seismic and modeling 
effort, (2) map the deformation recorded in the upper crust near the 
crater center that may yield important information about the kinematics 
of large bolide impacts, (3) image the peak ring and other morphologic 
features in the northwest quadrant of the crater to further understand 
the physical parameters of the Chicxulub impact structure, and (4) 
model the 3-D collapse of an asymmetric transient crater to help better 
understand the mechanics of large impact craters and to quantify the 
environmental effects of the K-T impact.

Description of the Activity

    The seismic survey will involve one vessel, the R/V Maurice Ewing. 
It will deploy an array of 20 airguns as an energy source, plus a 3 to 
6-km (1.6 to 3.2 n.mi.) towed hydrophone streamer. As the airgun array 
is towed along the survey line, the towed hydrophone streamer or Ocean 
Bottom Seismometers (OBSs) will receive the returning acoustic signals 
and transfer the data to the on-board processing system. Water depths 
within the study area range are less than 100 m (328 ft) and almost all 
of the survey will be conducted in water depths less than 50 m (164 
ft).
    The procedures to be used for the seismic study will be similar to 
those used during previous seismic surveys by LDEO in the equatorial 
Pacific Ocean (Carbotte et al., 1998, 2000). The proposed seismic 
surveys will use conventional seismic methodology, with a towed airgun 
array as the energy source and a towed hydrophone streamer and/or OBSs 
as the receiver system. The energy to the airgun array is compressed 
air supplied by compressors on board the source vessel.
    During the airgun operations, the vessel will travel at 7.4-9.3 km/
hr (4-5 knots), and seismic pulses will be emitted at intervals of 60-
90 sec (OBS lines) and approximately 20 sec Multi-Channel Seismic 
profiles (MCS lines). The 20-sec spacing corresponds to a shot interval 
of about 50 m (164 ft). The 60-90 sec spacing along OBS lines is to 
minimize reverberation from previous shot noise during OBS data 
acquisition, and the exact spacing will depend on water depth. The 20-
airgun array will include airguns ranging in chamber volume from 80 to 
850 in3. These airguns will be spaced in an approximate rectangle of 
dimensions of 35 m (115 ft) across track by 9 m (30 ft) along track.
    Along the selected lines, the OBSs will be positioned on the ocean 
bottom by the Maurice Ewing. After each line is shot, the Maurice Ewing 
will retrieve the OBSs, download the data, and refurbish the units 
before redeploying the OBSs along the next line that will be shot. 
During the Yucatan cruise, there will be three deployments of OBSs.
    In addition to the operations of the airgun array, the ocean floor 
will be mapped continuously throughout the entire cruise with an Atlas 
Hydrosweep DS-2 multibeam 15.5-kHz bathymetric sonar, and a 3.5-kHz 
sub-bottom profiler. Both of these sound sources will be operated 
simultaneously with the airgun array.
    The Atlas Hydrosweep is mounted on the hull of the Maurice Ewing, 
and it operates in three modes, depending on the water depth. There is 
one shallow water mode and there are two deep-water modes: an Omni mode 
and a Rotational Directional Transmission mode (RDT).
    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 Hydrosweep. The energy from the sub-
bottom profiler is directed downward by a 3.5 kHz transducer mounted in 
the hull of the Maurice Ewing. 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 1microPa, 800 watts, while nominal 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.
    Additional information on the airgun arrays, bathymetric sonars, 
and sub-bottom profiler specifications is also contained in the 
application (see ADDRESSES) and in previous Federal Register notices 
(April 14, 2003, 68 FR 17909, and September 17, 2003, 68 FR 54421).

Description of Habitat and Marine Mammals Affected by the Activity

    A detailed description of the Gulf of Mexico near the northern 
Yucatan Peninsula and its associated marine mammals can be found in the 
LDEO application and a number of documents referenced in the LDEO 
application, and is not repeated here. In the Gulf of Mexico near the 
Yucatan Peninsula, 29 marine mammal species are known to occur within 
the proposed study area. The species included in this application are 
the sperm whale (Physeter macrocephalus), pygmy sperm whale (Kogia 
breviceps), dwarf sperm whale (Kogia sima), Cuvier's beaked whale 
(Ziphius cavirostris), Sowerby's beaked whale (Mesoplodon 
densirostris), Gervais' beaked whale (Mesoplodon europaeus), 
Blainville's beaked whale (Mesoplodon densirostris), rough-toothed 
dolphin (Steno bredanensis), bottlenose dolphin (Tursiops truncatus), 
pantropical spotted dolphin (Stenella attenuata), Atlantic spotted 
dolphin (Stenella frontalis), spinner dolphin (Stenella longirostris), 
clymene dolphin (Stenella clymene), striped dolphin (Stenella 
coeruleoalba), short-beaked common dolphin (Delphinus delphis), long-
beaked common dolphin (Delphinus capensis), Fraser's dolphin 
(Lagenodelphis hosei), Risso's dolphin (Grampus griseus), melon-headed 
whale (Peponocephala electra), pygmy killer whale (Feresa attenuata), 
false killer whale (Pseudorca crassidens), killer whale (Orcinus orca), 
short-finned pilot whale (Globicephala macrorhynchus), long-finned 
pilot whale (Globicephala

[[Page 70002]]

melas), North Atlantic right whale (Eubalaena glacialis), humpback 
whale (Megaptera novaeangliae), minke whale (Balaenoptera 
acutorostrata), Bryde's whale (Balaenoptera edeni), sei whale 
(Balaenoptera borealis), fin whale (Balaenoptera physalus), and blue 
whale (Balaenoptera musculus). Seven of these species are listed as 
endangered under the U.S. Endangered Species Act (ESA): sperm, North 
Atlantic right, humpback, sei, fin, and blue whales, as well as West 
Indian manatee. Also, one species of pinniped, the hooded seal 
(Cystophora cristata), could potentially be encountered during the 
proposed seismic surveys. Additional information on most of these 
species is available at: http://www.nmfs.noaa.gov/prot_res/PR2/Stock--
Assessment--Program/sars.html.

Potential Effects on Marine Mammals

    NMFS' April 14, 2003, Federal Register notice (68 FR 17909) 
describes generally the anticipated effects of the Ewing's airguns and 
multibeam bathymetric sonar on marine mammals, including masking, 
behavioral disturbance, and potential hearing impairment and other 
physical effects. Possible effects of the sub-bottom profiler used in 
the projects are described in the previously mentioned Federal Register 
notices (68 FR 44291, July 28, 2003). The LDEO application for 
operations in Yucatan also provides information on what is known about 
the effects of LDEO's planned seismic survey on marine mammals. Past 
Federal Register notices for other LDEO seismic surveys include July 
28, 2003 (68 FR 44291), August 26, 2003 (68 FR 51240), September 12, 
2003 (68 FR 53714), September 17, 2003 (68 FR 54421), and October 21, 
2003 (68 FR 60086).

Estimates of Take for the Northern Yucatan Peninsula Cruise

    NMFS' current criteria for onset of Level A harassment of cetaceans 
and pinnipeds from impulse sound are, respectively, 180 and 190 re 1 
microPa root-mean-squared (rms). The rms pressure is an average over 
the pulse duration. The rms level of a seismic pulse is typically about 
10 dB less than its peak 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 the possibility of Level A harassment. LDEO has 
calculated the ``best estimates'' for the numbers of animals that could 
be taken by level B harassment during the proposed seismic survey at 
the northern Yucatan Peninsula using data on marine mammal abundance 
from a previous survey region, as shown in the predicted RMS radii 
table.
    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 20-gun array planned to be used for this project. The 
anticipated radius of influence of the multibeam sonar is less than 
that for the airgun array, so it is assumed that any marine mammals 
close enough to be affected by the multibeam sonar would already be 
affected by the airguns. Therefore, no additional incidental takings 
are included for animals that might be affected by the multibeam sonar.
    The following table explains the corrected density estimates as 
well as the best estimate of the numbers of each species that would be 
exposed to seismic sounds greater than 160 dB.

----------------------------------------------------------------------------------------------------------------
                                                                                                   ``Maximum
                                                                ``Best Estimate''              Estimate'' of the
                                                                 of the Number of  % of North      Number of
                            Species                                Exposures to     Atlantic      Exposures to
                                                                   Sound Levels    Population     Sound Levels
                                                                  [gteqt]160 dB                  [gteqt]160 dB
                                                                 ([gteqt]170 dB)                ([gteqt]170 dB)
----------------------------------------------------------------------------------------------------------------
Physeteridae                                                    .................  ..........  .................
Sperm whale                                                                     0          0                   0
Dwarf/Pygmy sperm whale                                                         0          0                   0
Ziphiidae                                                                       0          0                   0
Cuvier's beaked whale                                                           0          0                   0
Sowerby's beaked whale                                                          0          0                   0
Gervais' beaked whale                                                           0          0                   0
Blainville's beaked whale                                                       0          0                   0
Delphinidae                                                     .................  ..........  .................
Rough-toothed dolphin                                                    295 (85)       N.A.           443 (128)
Bottlenose dolphin                                                    9107 (2631)       N.A.       13,660 (3946)
Pantropical spotted dolphin                                             436 (126)       <0.7           654 (189)
Atlantic spotted dolphin                                                 988(285)       <1.8          1481 (428)
Spinner dolphin                                                            26 (7)    <0.2\a\             38 (11)
Clymene dolphin                                                                 0          0                   0
Striped dolphin                                                                 0          0                   0
Short-beaked common dolphin                                     .................  ..........  .................
Long-beaked common dolphin                                      .................  ..........  .................
Fraser's dolphin                                                            6 (1)       N.A.               10(2)
Risso's dolphin                                                             6 (1)          0               10(2)
Melon-headed whale                                                          6 (1)     0.1\a\               10(2)
Pygmy killer whale                                                              0          0                   0
False killer whale                                                      359 (104)       N.A.           539 (156)
Killer whale                                                                6 (1)        0.1               10(2)
Short-finned pilot whale                                                 205 (59)          0            308 (89)
Long-finned pilot whale                                         .................  ..........  .................
Mysticetes                                                      .................  ..........  .................
North Atlantic right whale                                                      0          0                   0
Humpback whale                                                                  0          0                   0
Minke whale                                                                     0          0                   0
Bryde's whale                                                                   0          0                   0
Sei whale                                                                       0          0                   0

[[Page 70003]]

 
Fin whale                                                                       0          0                   0
Blue whale                                                                      0          0                   0
Pinniped                                                        .................  ..........  .................
Hooded seal                                                                     0          0                   0
----------------------------------------------------------------------------------------------------------------
\a\ % of Gulf of Mexico population. N.A. = not available.

Conclusions- Effects on Cetaceans

    Strong avoidance reactions by several species of mysticetes to 
seismic vessels have been observed at ranges up to 8 km (4.3 nm) and 
occasionally as far as 30 km (16.2 nm) from the source vessel. In 
Arctic waters, some bowhead whales avoided waters within 30 km (16.2 
nm) of the seismic operation. However, reactions at such long distances 
appear to be atypical of other species of mysticetes and, even for 
bowheads, may only apply during migration.
    Odontocete reactions to seismic pulses, or at least those 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 in the vicinity of 
seismic vessels. There are documented instances of dolphins approaching 
active seismic vessels. However, dolphins as well as some other types 
of odontocetes will sometimes show avoidance responses and/or other 
changes in behavior when near operating seismic vessels.
    Taking account of the mitigation measures that are planned, effects 
on cetaceans are generally expected to be limited to avoidance of the 
area around the seismic operation and short-term changes in behavior, 
falling within the MMPA definition of Level B harassment.
    The numbers of odontocetes that may be harassed by the proposed 
activities are small relative to the population sizes of the affected 
stocks. A maximum of 13660, 1481, and 654 bottlenose, Atlantic spotted, 
and pantropical spotted dolphins, respectively, (the most abundant 
delphinids in the proposed survey area) are expected to be exposed to 
seismic sounds greater than or equal to 160 dB. However, the best 
estimates for bottlenose, Atlantic spotted, and pantropical spotted 
dolphins are 9107, 988, and 436, respectively. This represents zero to 
1.8 percent of the North Atlantic populations of these species based on 
population estimates. However, these dolphin species surveys have not 
been conducted for most of their range in the North Atlantic Ocean and 
adjacent waters. Therefore the true percentages of the populations that 
might be exposed to seismic sounds greater than or equal to 160 dB are 
likely to be much less than 1.8 percent, as the population sizes and 
the zero to 1.8 percent are based on only a small fraction of their 
range and their actual population sizes are much larger.
    In light of the type of take expected and the small percentages of 
affected stocks, the action is expected to have no more than a 
negligible impact on the affected species or stocks of marine mammals. 
In addition, mitigation measures such as controlled vessel speed, 
course alteration, look-outs, ramp-ups, and power-downs when marine 
mammals are seen within defined ranges (see Mitigation) should further 
reduce short-term reactions to disturbance, and minimize any effects on 
hearing sensitivity.

Conclusions- Effects on Pinnipeds

    Pinnipeds are not expected to be encountered during the proposed 
seismic survey at the northern Yucatan Peninsula in the Gulf of Mexico. 
However, a conservative estimate of a maximum of 5 hooded seals may be 
affected by a portion of the proposed survey in the Gulf of Mexico if 
they are encountered. Responses of pinnipeds to acoustic disturbance 
are variable, but usually quite limited. If hooded seals were 
encountered, the proposed seismic survey would have, at most, a short-
term effect on their behavior, falling within the definition of Level B 
harassment. The action would therefore have no more than a negligible 
impact on the affected species or stocks of pinnipeds.
Mitigation
    The following mitigation measures are proposed for the subject 
seismic surveys, provided that they do not compromise operational 
safety requirements: (1) Speed and course alteration; (2) power-down 
and shut-down procedures; and (3) ramp-up procedures. Mitigation also 
includes marine mammal monitoring in the vicinity of the arrays. These 
mitigation measures are further described here.
    These mitigation measures will incorporate use of established 
safety radii which are equal to 1.5 times the distance from the arrays 
where sound levels [gteqt]190 and 180 dB re 1 microPa rms (the criteria 
for onset of Level A harassment for pinnipeds and cetaceans 
respectively) are predicted to be received. LDEO has modeled the sound 
pressure fields for the 20-gun array in relation to distance and 
direction from the airguns and predicts that the 190-dB and 180-dB 
distance from the airgun array will be 275 ft (902 m) and 900 ft (2935 
m) respectively.
    The directional nature of the 20-airgun array to be used in this 
project is also an important mitigating factor. The airguns comprising 
these arrays will be spread out horizontally, so that the energy from 
the arrays will be directed mostly downward, resulting in lower sound 
levels at any given horizontal distance than would be expected at that 
distance if the source were omnidirectional with the stated nominal 
source level. Because the actual seismic source is a distributed sound 
source (20 guns) rather than a single point source, the highest sound 
levels measurable at any location in the water will be less than the 
nominal source level.
Speed and Course Alteration
    If a marine mammal is detected outside the appropriate safety 
radius and, based on its position and the relative motion, is likely to 
enter the safety radius, the vessel's speed and/or direct course will 
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 radius. If the mammal 
appears likely to enter the safety radius, further mitigative actions 
will be taken, i.e., either further course alterations or shutdown of 
the airguns.

[[Page 70004]]

Power-down and Shut-down Procedures
    Airgun operations will be powered-down (or shut-down) immediately 
when cetaceans or pinnipeds are seen within or about to enter the 
appropriate safety radius. 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 
marine mammal enter the safety radius, the airguns will be powered-down 
before the mammal is within the safety radius. Likewise, if a mammal is 
already within the safety zone when first detected, the airguns will be 
powered-down immediately. If a marine mammal is seen within the 
appropriate safety radius of the array while the guns are powered-down, 
airgun operations will be shut-down. For the power-down procedure for 
the 20-gun array, one 80 in\3\ airgun will continue to be operated 
during the interruption of seismic survey. Airgun activity (after both 
power-down and shut-down procedures) will not resume until any marine 
mammal has cleared the safety radius. The mammal has cleared the safety 
radius if it is visually observed to have left the safety radius, or if 
it has not been seen within the zone for 15 min (small odontocetes and 
pinnipeds) or 30 min (mysticetes and large odontocetes, including 
sperm, pygmy sperm, dwarf sperm, beaked and bottlenose whales).
Ramp-up Procedure
    When airgun operations with the 20-gun array commence after a 
certain period without airgun operations, the number of guns firing 
will be increased gradually, or ``ramped up'' (also described as a 
``soft start''). Operations will begin with the smallest gun in the 
array (80 in\3\). Guns will be added in sequence such that the source 
level of the array will increase in steps not exceeding 6 dB per 5-min 
period over a total duration of approximately 25 minutes. Throughout 
the ramp-up procedure, the safety zone for the full 20-gun array will 
be maintained. Given the presence of the streamer and airgun array 
behind the vessel, the turning rate of the vessel with trailing 
streamer and array is no more than five degrees per minute, limiting 
the maneuverability of the vessel during operations.
    The ``ramp-up'' procedure will be required under the following 
circumstances. Under normal operational conditions (vessel speed 4 
knots, or 7.4 km/hr), a ramp-up would be required after a power-down or 
shut-down period lasting about 8 minutes or longer if the Ewing was 
towing the 20-gun array. At 4 knots, the source vessel would travel 900 
m (2953 ft) during an 8-minute period. If the towing speed is reduced 
to 3 knots or less, as sometimes required when maneuvering in shallow 
water, it is proposed that a ramp-up would be required after a ``no 
shooting'' period lasting 10 minutes or longer. At towing speeds not 
exceeding 3 knots, the source vessel would travel no more than 900 m 
(3117 ft) in 10 minutes. Based on the same calculation, a ramp-up 
procedure would be required after a 6 minute period if the speed of the 
source vessel was 5 knots.
    Ramp-up will not occur if the safety radius has not been visible 
for at least 30 min prior to the start of operations in either daylight 
or nighttime. If the safety radius has not been visible for that 30 
minute period (e.g., during darkness or fog), ramp-up will not commence 
unless at least one airgun has been firing continuously during the 
interruption of seismic activity.
    Comments on past proposed IHAs raised the issue of prohibiting 
nighttime operations as mitigation. However, this is not practicable 
due to cost considerations. The daily cost to the federal government to 
operate vessels such as Ewing is approximately $33,000 to $35,000/day 
(Ljunngren, pers. comm. May 28, 2003). If the vessels were prohibited 
from operating during nighttime, it is possible that each trip would 
require an additional three to five days, or up to $175,000 more, 
depending on average daylight at the time of work.
    Taking into consideration the additional costs of prohibiting 
nighttime operations and the likely impact of the activity (including 
all mitigation and monitoring), NMFS has determined that the proposed 
mitigation 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 (at least one hour in advance), thereby giving them an 
opportunity to avoid the approaching array; if ramp-up is required 
after an extended power-down, two marine mammal observers will be 
required to monitor the safety radii using night vision devices for 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; and ramp-up may occur at night only if 
one airgun with a sound pressure level of at least 180 dB has been 
maintained during interruption of seismic activity. Therefore it is 
likely that the 20-gun array will not be ramped-up from a shut-down at 
night.

Marine Mammal Monitoring

    LDEO must have at least two observers on board the vessel, and at 
least one must be an experienced marine mammal observer that NMFS 
approves. These observers will monitor marine mammals near the seismic 
source vessel during all daytime airgun operations and during any 
nighttime start-ups of the airguns. During daylight, vessel-based 
observers will watch for marine mammals near the seismic vessel during 
periods with shooting (including ramp-ups), and for 30 minutes prior to 
the planned start of airgun operations after an extended shut-down.
    The observers will be on duty in shifts of no longer than 4 hours. 
The second observer must also be on watch part of the time, including 
the 30-minute periods preceding startup of the airguns and during ramp-
ups. Use of two simultaneous observers will increase the likelihood 
that marine mammals near the source vessel are detected. LDEO 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 not on duty.
    The observer(s) will watch for marine mammals from the highest 
practical vantage point on the vessel, which is either the bridge or 
the flying bridge. On the bridge of the Maurice Ewing, the observer's 
eye level will be 11 m (36 ft) above sea level, allowing for good 
visibility within a 210[deg] arc. If observers are stationed on the 
flying bridge, the eye level will be 14.4 m (47.2 ft) above sea level. 
The observer(s) will systematically scan the area around the vessel 
with reticle binoculars (e.g., 7 X 50 Fujinon) and with the naked eye 
during the daytime. Laser rangefinding binoculars (Leica LRF 1200 laser 
rangefinder or equivalent) will be available to assist with distance 
estimation. The observers will be used to determine when a marine 
mammal is in or near the safety radii so that the required mitigation 
measures, such as course alternation and power-down or shut-down, can 
be implemented. If the airguns are powered or shut down, observers will 
maintain watch to determine when the animal is outside the safety 
radius.
    Observers will not be on duty during ongoing seismic operations at 
night; bridge personnel will watch for marine mammals during this time 
and will call for the airguns to be powered-down if marine mammals are 
observed in or

[[Page 70005]]

about to enter the safety radii. If the airguns are ramped-up at night, 
two marine mammal observers will monitor for marine mammals for 30 
minutes prior to ramp-up and during the ramp-up using night vision 
equipment that will be available (ITT F500 Series Generation 3 
binocular image intensifier or equivalent).
    Comments on past proposed IHAs suggested that NMFS require the use 
of passive acoustic monitoring, which is generally more effective than 
visual observations. Shipboard passive acoustics would not allow those 
on board the vessel to determine a marine mammal's distance from the 
vessel through triangulation; the vessel operator could determine only 
that a marine mammal is some unknown distance from the vessel. In order 
to triangulate on the animal, a system similar to that used in the Gulf 
of Mexico Sperm Whale Seismic Study (SWSS) in May 2003 is necessary. 
That passive acoustical monitoring equipment is not the property of 
LDEO or the Ewing and is not available for the Yucatan cruises. LDEO is 
presently evaluating the scientific results of the passive sonar from 
the SWSS trip to determine whether it is practical to incorporate it 
into future seismic research cruises. NMFS expects a report on this 
analysis shortly.
Reporting
    LDEO will submit a report to NMFS within 90 days after the end of 
the cruise, which is predicted to occur on or around April 4, 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.
ESA
    Under section 7 of the ESA, the National Science Foundation(NSF), 
the agency funding LDEO, has begun consultation on the proposed 
issuance of an IHA under section 101(a)(5)(D) of the MMPA for this 
activity. Consultation will be concluded prior to the issuance of an 
IHA. NSF has initiated consultation with the U.S. Fish and Wildlife 
Service on West Indian Manatees.
National Environmental Policy Act (NEPA)
    The NSF has prepared an EA for the northern Yucatan Peninsula 
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 at the northern Yucatan Peninsula in the Gulf of Mexico 
will 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.
    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, no take by injury and/or 
death is anticipated, and the potential for temporary or permanent 
hearing impairment is low and will be avoided through the incorporation 
of the mitigation measures mentioned in this document. In addition, the 
proposed seismic program is not expected to interfere with any 
subsistence hunts, since operations in the whaling and sealing areas 
will be limited or nonexistent.
Proposed Authorization
    NMFS proposes to issue an IHA to LDEO for conducting a seismic 
surveys at the northern Yucatan Peninsula in the Gulf of Mexico, 
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 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: December 4, 2003.
Phil Williams,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 03-30922 Filed 12-15-03; 8:45 am]
BILLING CODE 3510-22-S