[Federal Register Volume 69, Number 60 (Monday, March 29, 2004)]
[Notices]
[Pages 16233-16240]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-6970]


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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 issuance of an incidental take authorization.

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SUMMARY: In accordance with provisions of the Marine Mammal Protection 
Act (MMPA) as amended, notification is hereby given that NMFS has 
issued an Incidental Harassment Authorization (IHA) to take marine 
mammals by harassment incidental to conducting oceanographic surveys 
off the northern Yucatan Peninsula in the Gulf of Mexico to Lamont-
Doherty Earth Observatory (LDEO).

DATES: Effective from February 27, 2004, through February 26, 2005.

ADDRESSES: A copy of the IHA and the application are available by 
writing to Mr. P. Michael Payne, Chief, Marine Mammal Conservation 
Division, Office of Protected Resources, NMFS, 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

[[Page 16234]]

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: 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 (Secretary) 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 and comment.
    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 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. 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 195 km (121 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

    Information of the work proposed for 2004 is contained in the 
proposed authorization notice (68 FR 70000, December 16, 2003), and in 
the application and in the Final Yucatan Environmental Assessment for 
oceanographic surveys in the Gulf of Mexico off the northern Yucatan 
Peninsula (LDEO, 2003) which are available (see ADDRESSES).
    In spring 2003, LDEO conducted an acoustic calibration study in the 
northern Gulf of Mexico. The purpose of the study was to calibrate 
LDEO's various seismic sources and determine the distances at which 
received sound levels diminish below levels that may result in take of 
marine mammals. NMFS received the results of this study on February 20, 
2004. They are the first measurements of sound propagation in shallow 
water using this particular seismic source and are the best available 
science. The data indicate that the safety zone radius used for 
mitigation to prevent Level A harassment of marine mammals should be 
larger than the safety radius in the proposed IHA. The results of the 
study are available (See ADDRESSES).

Changes from the Proposed IHA

    The calibration study data indicate that the 180 dB isopleth is at 
a distance of 3500 m (11483 ft) from the array, rather than the 900 m 
(2935 ft) estimated in the application and proposed IHA. This new data 
changes the take estimates for marine mammals. Refer to the Estimates 
of Take for the Northern Yucatan Peninsula Cruise in this Notice for 
the updated take estimates.
    In light of the new data, NMFS has imposed additional mitigation 
measures for this seismic survey. First, the safety radius will be 3500 
m (11483 ft) rather than the proposed 1350 m (4429 ft) (which is 1.5 
times the estimated 180 dB isopleth). Second, in addition to visual 
observers, LDEO will use passive acoustic monitoring (PAM) whenever the 
vessel is operating in waters deep enough for the PAM hydrophone array 
to be towed. Third, LDEO will increase the number of visual observers 
from two to at least four, and several acousticians will be available 
to monitor the PAM system. Finally, LDEO will use Big Eyes binoculars 
to enable observers to detect marine mammals at greater distances from 
the vessel. See Mitigation for more information.
    NMFS has also determined that takes of pinnipeds are not likely to 
occur in the action area. Therefore, hooded seals are not included in 
this IHA.

Comments and Responses

    A notice of receipt of the LDEO northern Yucatan application and 
proposed IHA was published in the

[[Page 16235]]

Federal Register on December 16, 2003 (68 FR 70000). During the 30-day 
comment period, comments were received from the Animal Welfare 
Institute, the Center for Biological Diversity (CBD), and an 
individual. In addition, NMFS received supplemental comments from CBD 
on February 26, 2004. Those comments were received well after the 
comment period closed and shortly before the subject seismic surveys 
were scheduled to begin. Therefore, NMFS did not consider them in 
issuing this IHA, except where they overlap with CBD's first set of 
comments.
    Comment 1: One commentor states that it is the job of the Office of 
Protected Resources to administer programs that deal with the 
protection, conservation, and recovery of species protected under the 
Endangered Species Act and they must pay attention to the fact that 
marine mammals are sentient beings.
    Response: NMFS affirms that marine mammals should be protected and 
encouraged to develop to the greatest extent feasible commensurate with 
sound policies of resource management. In that regard, the MMPA was 
amended in 1981 and 1994 to allow for the taking (by harassment, injury 
and mortality) of marine mammals by otherwise lawful activities 
provided that the total taking by the activity is not having more than 
a negligible impact on affected marine mammal stocks, and would not 
have an unmitigable adverse impact on the availability of those marine 
mammal stocks for subsistence uses. For the proposed activity, the 
requisite findings have been made, as explained in this document.
    Comment 2: The Animal Welfare Institute objects to the issuance of 
an Incidental Harassment Authorization for this project based on the 
precautionary principle. They feel that it is dangerous to experiment 
with sounds as loud as these in the open ocean.
    Response: As mentioned in the previous comment, the MMPA requires 
the Secretary to authorize the taking of marine mammals provided 
certain conditions are met. For this authorization, NMFS believes it 
has applied a precautionary approach that is consistent with the 
requirements of the MMPA and based on the best available science. That 
is, LDEO has implemented several mitigation measures that will minimize 
harassment takings to the lowest level practicable (as required by the 
MMPA). These mitigation measures include (1) establishment and 
monitoring of safety zones to prevent Level A harassment; (2) 
implementation of ramp-up to allow marine mammals sufficient time to 
leave the immediate vicinity of the seismic array before sounds become 
annoying or dangerous; (3) establishment of a 30-minute pre-ramp-up 
monitoring program; and (4) passive acoustic monitoring where 
practicable. The research being conducted is not an ``experiment'' but 
scientifically valid peer-reviewed research being undertaken to improve 
knowledge of geological history. Seismic arrays were developed to 
mitigate impacts to marine life by eliminating the use of large 
explosives used in earlier decades to explore for oil and conduct 
scientific research.
    Comment 3: CBD believes NMFS has not demonstrated that the LDEO 
project will take only small numbers of marine mammals.
    Response: NMFS believes that the small numbers requirement has been 
satisfied. The U.S. District Court for the Northern District of 
California held in NRDC v. Evans that NMFS' regulatory definition of 
``small numbers'' improperly conflates it with the ``negligible 
impact'' definition. Even if that is the case, NMFS has made a separate 
determination that the numbers of takes of the affected marine mammal 
species will be small. The best estimate of takes indicates that 9.4 
percent or less of the affected species or stocks will be harassed. 
Although the absolute numbers may arguably not be small, they are small 
relative to the population sizes.
    Comment 4: CBD states that NMFS does not adequately analyze the 
depths of water in which the surveys will take place and how the 
difference in depths affect the impacts to marine mammals.
    Response: The LDEO application describes how seismic sounds can be 
received in the ocean. Seismic sound received at any given point will 
arrive via a direct path, indirect paths that include reflection form 
the sea surface and bottom, and often indirect paths including segments 
through the bottom sediments. Sound propagating via indirect paths 
travel longer distances and often arrive later than sounds arriving via 
a direct path. These variations in travel time have the effect of 
lengthening the duration of the received pulse.
    Received levels of low-frequency underwater sounds diminish close 
to the surface because of pressure-release and interference phenomena 
that occur at and near the surface (Urick, 1983; Richardson et al. 
1995). Paired measurements of received airgun sounds at depths of 3 m 
(9.8 ft) vs 9 m (29.5 ft) or 18 m (59 ft) have shown that received 
levels are typically several decibels lower at 3 m (Greene and 
Richardson, 1988).
    During a 2003 study in the northern Gulf of Mexico, LDEO obtained 
measurements of received sound levels as a function of distance from 
LDEO's airgun arrays. The report on those ``calibration measurements'' 
has been completed. The measurement indicate that received levels in 
deep water (3200 m) (10499 ft) diminish more rapidly with increasing 
distance, whereas levels in shallow water (30 m) (98 ft) diminish less 
rapidly. The 2003 calibration results show that the measured depth-
specific 180 dB distance is 3500 m (11483 ft). The required mitigation 
measures have been modified to account for this.
    LDEO plans to obtain additional data on received levels of the 
sounds from the various LDEO airgun configurations during a follow-up 
calibration study in the northern Gulf of Mexico in April 2004. Plans 
for that study call for measurements in shallow, intermediate, and deep 
water.
    Comment 5: CBD states that there is no mention of the compounded 
impact of the 20-airgun array's seismic output along with the two other 
acoustical data acquisition systems, the sonar and sub-bottom profiler. 
CBD states that the proposed IHA Federal Register notice provides no 
estimate of take from the sonar and profiler individually or from all 
three sources collectively, and instead assumed that any marine mammals 
close enough to be affected by the multibeam sonar would already be 
affected by the airguns. Therefore, no additional allowance is included 
for animals that might be affected by the multibeam sonar. CBD comments 
that this explanation does not account for times when all three sources 
may not be operating simultaneously or provide any discussion of the 
enhanced impact of multiple acoustic sources when operating together.
    Response: As NMFS indicated in the FR notice of the proposed IHA, 
the multibeam sonar has an anticipated radius of influence less than 
that for the airgun array. It is further stated that marine mammals 
close enough to be affected by the multibeam sonar would already be 
affected by the airguns. Therefore, no additional allowance is included 
for animals that might be affected by the sonar. There is no enhanced 
impact of using the multibeam when operating it together with the 
airgun array. The sub-bottom profiler would not enhance impacts, since 
the radii of influence are smaller for the profiler than those of the 
airgun array.

[[Page 16236]]

    It is true that there are no estimates of take for times when the 
multibeam sonar and/or sub-bottom profiler are operated without 
airguns. This is because the 160-dB and 180-dB isopleths of the sub-
bottom profiler and multibeam are small. Durations of exposure and of 
behavioral responses to these sources would be brief, and any 
behavioral reactions would not rise to the level of take. Also, visual 
monitoring would be most effective at those shorter distances from the 
vessel, allowing for greater detection and avoidance of marine mammals 
in the vicinity.
    Comment 6: CBD states that NMFS' analysis of mitigation measures to 
ensure least practicable impact is flawed because its analysis of 
impacts is incomplete, for the following reasons. First, the safety 
radii have not been verified. Also, the only proposed marine mammal 
detection method is visual surveillance by daytime observers. Although 
bridge personnel will keep watch at night, nighttime detection rates of 
marine mammals are probably very low. There is no discussion of why 
nighttime operations are considered necessary, why experienced marine 
mammal observers will not be on duty during nighttime hours, how 
effective any observation efforts are expected to be, or why 
alternative means of ensuring that the required monitoring program is 
likely to detect most marine mammals in or near the safety zones are 
not identified and required. Also, NMFS has failed to mention or 
require any exclusion zones to avoid seismic operations in coastal 
areas and key habitat for feeding, mating, breeding, and migration.
    Response: NMFS believes that the required mitigation measures 
ensure the least practicable adverse impacts. The 180-dB isopleth 
modeling has been recently verified and NMFS' IHA has accordingly set 
the safety radius as 3500 m (11483 ft) from the arrays, within which 
sound levels greater than or equal to 180 dB re 1 microPa rms (the 
criteria for onset of Level A harassment for cetaceans) are predicted 
to be received.
    Nighttime operations are necessary due to cost considerations. The 
daily cost to the Federal Government to operate vessels such as Ewing 
and the Seaward Johnson 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.
    NMFS agrees that the effectiveness of nighttime visual monitoring 
is limited. LDEO will now also incorporate passive acoustic monitoring 
whenever depth conditions allow. LDEO and the marine mammal observers 
have attended an orientation course for the use of the Lamont Seamap 
system onboard the Ewing. In addition to the observers, several 
acousticians from the science party will be able to monitor the passive 
acoustic system.
    Taking into consideration the additional costs of prohibiting 
nighttime operations and the likely impact of the activity (including 
all required mitigation and monitoring), NMFS has determined that the 
IHA's requirements ensure 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 1 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; start-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 
virtually impossible that the 20-gun array will be ramped-up from a 
shut-down at night.
    In regards to exclusion zones, during the period of the survey, 
marine mammals will be dispersed throughout the proposed study area in 
the southern Gulf of Mexico. No concentrations of marine mammals or 
marine mammal prey species are known to occur in the study area at that 
time of year. The airgun operations will not result in any permanent 
impact on habitats used by marine mammals or their food sources. The 
use of the OBS receivers may have a temporary disturbance to sediments 
and benthic organisms, but the area that may be disturbed is a small 
fraction of marine mammal habitat and the habitat of their prey 
species. The airguns are used as the energy source for the seismic 
surveys because they do not kill fish. Injurious effects on fish would 
be limited to short distances. The ramp-ups will also give the fish an 
opportunity to move away from the sound source as the strength of the 
sound increases.
    Comment 7: CBD believes that in order for NMFS to comply with the 
National Environmental Policy Act (NEPA), it must demonstrate that it 
has fully analyzed the impacts of, alternatives to, and mitigation 
measures for the project prior to issuing an IHA for the LDEO project. 
NMFS must assess the cumulative impacts of the project in conjunction 
with other actions on the environment.
    Response: NMFS follows NEPA regulations and NOAA Administrative 
Order 216-6 (Environmental Review Procedures for Implementing the 
National Environmental Policy Act, May 20, 1999) before making a 
determination on whether it will adopt another federal agency's NEPA 
document, or prepare its own. Critical to this determination is the 
quality of another agency's NEPA document, whether it fully addresses 
the action proposed by NOAA Fisheries, and whether NOAA Fisheries' 
proposed action is significant as defined in 40 CFR 1508.27 and NAO 
216-6, section 6.01. As noted in the proposed authorization notice (68 
FR 60086; October 21, 2003), an EA was prepared by National Science 
Foundation (NSF) and released to the public by NOAA Fisheries. That EA 
contained a complete description of the proposed action and identified 
alternatives to that action; a description of the affected environment; 
an assessment of impacts, including unavoidable impacts, indirect 
impacts and cumulative impacts; and the mitigation measures to reduce 
impacts to the lowest level practicable. In accordance with NAO 216-6, 
NMFS has reviewed the information contained in the NSF EA and 
determined that it accurately and completely describes the proposed 
action alternative, reasonable additional alternatives, and the 
potential impacts on marine mammals, endangered species, and other 
marine life that could be impacted by the preferred alternative and the 
other alternatives. Based on this review and analysis, NMFS adopted the 
NSF EA under 40 CFR 1506.3 and made its own Finding of No Significant 
Impact (FONSI). As a result, NMFS has determined that it is not 
necessary to issue either a new EA, supplemental EA or an environmental 
impact statement for the issuance of an IHA to LDEO for this activity.

Description of Habitat and Marine Mammals Affected by the Activity

    A detailed description of the Gulf of Mexico off 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

[[Page 16237]]

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 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. 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

    A discussion on potential impacts on marine mammals was provided in 
the Federal Register notice 68 FR 70000 (December 16, 2003) and in the 
LDEO application.

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; (3) ramp-up procedures; and (4) marine mammal 
and sea turtle monitoring in the vicinity of the arrays through 
observers and passive acoustic monitoring. These mitigation measures 
are further described here.
    These mitigation measures will incorporate use of established 
safety radius which LDEO has measured and modeled. The sound pressure 
fields for the 20-gun array in relation to distance and direction from 
the airguns are predicted to be at 3500 m (11483 ft) from the airgun 
array.
    The directional nature (vertical beam-forming) 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. Also, 
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 enter 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.

Power-down and Shut-down Procedures

    Airgun operations will be powered-down (or shut-down) immediately 
when cetaceans or sea turtles are seen within or about to enter the 
safety radius. If a marine mammal is detected outside the safety radius 
but appears likely to enter it, 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 marine 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 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 or sea turtle 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) or 30 min 
(mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf 
sperm, beaked and bottlenose whales). These mitigation measures also 
apply in the case of sea turtles.

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 in3). 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, 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.Passive

[[Page 16238]]

acoustic monitoring has been added to the mitigation measures. The 
Seamap system has four hydrophones which allow an observer to take a 
bearing on the vocalization of a marine mammal. Verification can then 
be made through visual observation by the marine mammal observers.

Marine Mammal Monitoring

    LDEO must have at least four observers on board the vessel, and at 
least two must be experienced marine mammal observers that NMFS has 
approved in advance of the cruise. These observers will monitor marine 
mammals and sea turtles near the seismic source vessel during all 
daytime airgun operations and during any nighttime ramp-ups of the 
airguns. 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 an extended shut-down.
    At least two observers will be on duty in shifts of no longer than 
4 hours. At least three observers must be on watch during the 30-minute 
periods preceding startup of the airguns and during ramp-ups. Use of 
more than one observer will increase the likelihood that marine mammals 
near the source vessel are detected. LDEO bridge personnel will also 
assist in detecting marine mammals and sea turtles 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 observers will watch for marine mammals and sea turtles 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 observers will systematically scan the area around the 
vessel with reticle binoculars (e.g., 7 X 50 Fujinon), with a set of 
Big Eyes binoculars, and with the naked eye during the daytime. Laser 
range-finding 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 or a 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 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 and sea turtles 
during this time and will call for the airguns to be powered-down if 
marine mammals are observed in or about to enter the safety radii. If 
the airguns are ramped-up at night, at least three marine mammal 
observers will monitor for marine mammals and sea turtles 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).

Reporting

    LDEO will submit a report to NMFS within 90 days after the end of 
the cruise, which is predicted to be 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.

Estimates of Take for the Northern Yucatan Peninsula Cruise

    NMFS' current criteria for onset of Level A harassment of cetaceans 
from impulse sound is 180 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, 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 to the lowest level practicable. 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.
    These estimates are based on a consideration of the number of 
marine mammals that might be exposed to sound levels equal to or 
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 or equal to 160 dB.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              ``Best Estimate'' of the Number of
                   Species                         Exposures to Sound Levels        % of North Atlantic Population       Requested Take Authorization
                                                 [gteqt]160 dB ([gteqt]170 dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Physeteridae                                  ..................................  ..................................  ..................................
Sperm whale                                                                    0                                   0                                  10
Dwarf/Pygmy sperm whale                                                        0                                   0                                  10
Ziphiidae                                     ..................................  ..................................  ..................................
Cuvier's beaked whale                                                          0                                   0                                  10
Sowerby's beaked whale                                                         0                                   0                                  10
Gervais' beaked whale                                                          0                                   0                                  10
Blainville's beaked whale                                                      0                                   0                                  10
Delphinidae                                   ..................................  ..................................  ..................................
Rough-toothed dolphin                                                   393 (99)                             N.A.\2\                                 590
Bottlenose dolphin                                                  12142 (3054)                                 9.4                               18213

[[Page 16239]]

 
Pantropical spotted dolphin                                            581 (146)                                 1.0                                 872
Atlantic spotted dolphin                                              1317 (331)                                 2.4                                1975
Spinner dolphin                                                           34 (9)                              0.3\1\                                 100
Clymene dolphin                                                                0                                   0                                 100
Striped dolphin                                                                0                                   0                                 100
Short-beaked common dolphin                   ..................................  ..................................                                   5
Long-beaked common dolphin                    ..................................  ..................................                                   5
Fraser's dolphin                                                           9 (2)                                 6.7                                 100
Risso's dolphin                                                            9 (2)                                <0.1                                  10
Melon-headed whale                                                         9 (2)                              0.2\1\                                  15
Pygmy killer whale                                                             0                                   0                                  15
False killer whale                                                     479 (120)                             N.A.\2\                                 718
Killer whale                                                               9 (2)                                 0.1                                  10
Short-finned pilot whale                                                274 (69)                                <0.1                                 410
Long-finned pilot whale                                                        0                                   0                                   5
Mysticetes                                    ..................................  ..................................  ..................................
North Atlantic right whale                                                     0                                   0                                   2
Humpback whale                                                                 0                                   0                                   2
Minke whale                                                                    0                                   0                                   2
Bryde's whale                                                                  0                                   0                                   5
Sei whale                                                                      0                                   0                                   2
Fin whale                                                                      0                                   0                                   2
Blue whale                                                                     0                                   0                                   2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\% of Gulf of Mexico population.
\2\N.A. = not available.

Conclusions

    NMFS has 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.

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 short-term 
avoidance of the area around the seismic operation, 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. The best estimates for exposure to seismic sounds greater than 
or equal to 160 dB are 12142, 1317, and 581 for bottlenose, Atlantic 
spotted, and pantropical spotted dolphins, respectively (the most 
abundant delphinids in the proposed survey area). This represents 
between 1 and 9.4 percent of the North Atlantic populations of these 
species based on population estimates. However, surveys for these 
dolphin species 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, as the 
population sizes 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 (Level B harassment) 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 and biological observers, 
the use of passive acoustics, ramp-ups, and power-downs and shut-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.

ESA

    NMFS issued a biological opinion regarding the effects of this 
action on ESA-listed species and critical habitat. That biological 
opinion concluded that this action is not likely to jeopardize the 
continued existence of listed species or

[[Page 16240]]

result in the destruction or adverse modification of critical habitat. 
A copy of the Biological Opinion is available upon request (see 
ADDRESSES).

NEPA

    The NSF made a Finding of No Significant Impact (FONSI) 
determination on October 2, 2003, based on information contained within 
its EA, that implementation of the subject action is not a major 
Federal action having significant effects on the environment within the 
meaning of Executive Order 12114. NSF determined therefore, that an 
environmental impact statement would not be prepared. On December 16, 
2003 (68 FR 70000), NMFS noted that the NSF had prepared an EA for the 
Yucatan Peninsula surveys and made this EA was available upon request. 
In accordance with NOAA Administrative Order 216-6 (Environmental 
Review Procedures for Implementing the National Environmental Policy 
Act, May 20, 1999), NMFS has reviewed the information contained in 
NSF's EA and determined that the NSF EA accurately and completely 
describes the proposed action alternative, reasonable additional 
alternatives, and the potential impacts on marine mammals, endangered 
species, and other marine life that could be impacted by the preferred 
alternative and the other alternatives. Therefore, it is not necessary 
to issue a new EA, supplemental EA or an environmental impact statement 
for the issuance of an IHA to LDEO for this activity. Based on this 
review and analysis, NMFS is adopting the NSF EA under 40 CFR 1506.3 
and has made its own FONSI. A copy of the NSF EA and the NMFS FONSI for 
this activity is available upon request (see ADDRESSES).

Authorization

    NMFS has issued an IHA to take marine mammals, by harassment, 
incidental to conducting a seismic surveys in the northern Yucatan 
Peninsula in the Gulf of Mexico to LDEO for a 1-year period, provided 
the mitigation, monitoring, and reporting requirements are undertaken.

    Dated: March 23, 2004.
Laurie K. Allen,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 04-6970 Filed 3-26-04; 8:45 am]
BILLING CODE 3510-22-S