[Federal Register: February 21, 2008 (Volume 73, Number 35)]
[Notices]
[Page 9526-9535]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21fe08-43]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF33
Small Takes of Marine Mammals Incidental to Specified Activities;
Marine Geophysical Survey off Central America, February-April 2008
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental take authorization.
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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA)
regulations, notification is hereby given that NMFS has issued an
Incidental Harassment Authorization (IHA) to Lamont-Doherty Earth
Observatory (L-DEO), a part of Columbia University, for the take of
marine mammals, by Level B harassment only, incidental to conducting a
marine seismic survey off Central America during February-April, 2008.
DATES: Effective February 15, 2008, through February 14, 2009.
ADDRESSES: A copy of the IHA and the application are available by
writing to P. Michael Payne, 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. A copy of the application
containing a list of the references used in this document may be
obtained by writing to the address specified above, telephoning the
contact listed below (see FOR FURTHER INFORMATION CONTACT), or visiting
the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Documents cited in this notice may be
viewed, by appointment, during regular business hours, at the
aforementioned address.
FOR FURTHER INFORMATION CONTACT: Candace Nachman, Office of Protected
Resources, NMFS, (301) 713-2289 x156.
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.
Authorization shall be granted if NMFS finds that the taking will
have a negligible impact on the species or stock(s), will not have an
unmitigable adverse impact on the availability of the species or
stock(s) for subsistence uses (where relevant), and if the permissible
methods of taking and requirements pertaining to the mitigation,
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.
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].
[[Page 9527]]
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 approve or deny the authorization.
Summary of Request
On August 24, 2007, NMFS received an application from L-DEO for the
taking, by Level B harassment only, of small numbers of 26 species of
marine mammals incidental to conducting, under a cooperative agreement
with the National Science Foundation (NSF), a seismic survey in the
Pacific Ocean and Caribbean Sea off Central America as part of the
Subduction Factory (SubFac) initiative of NSF's MARGINS program from
January-March, 2008. (The dates of the cruise were subsequently moved
to February-April 2008.) The purpose of the research program was
outlined in NMFS' notice of the proposed IHA (72 FR 71625, December 18,
2007).
Description of the Activity
The seismic survey will involve one source vessel, the R/V Marcus
G. Langseth (Langseth), which will operate in two regions during the
proposed survey: the Caribbean Sea and the Pacific Ocean. The Langseth
will deploy an array of 36 airguns (6,600 in3) as an energy source and,
at times, a receiving system consisting of a 6-km (3.7-mi) towed
hydrophone streamer. The streamer will be towed at a depth of 5-8 m
(16-26 ft). As the airgun array is towed along the survey lines, the
hydrophone streamer will receive the returning acoustic signals and
transfer the data to the on-board processing system. In the Caribbean
region, the Langseth will also deploy Ocean Bottom Seismometers (OBSs)
to receive the returning acoustic signals. In the Pacific Ocean, a
second vessel, the R/V New Horizon, will deploy and retrieve the OBSs.
For the first part of the cruise, the Langseth is expected to
depart Puerto Limon, Costa Rica, on approximately February 16, 2008 for
the study area in the Caribbean Sea (see Figure 1 in the application).
The seismic survey will commence following the transit and deployment
of the streamer and airgun array. Following approximately 25 days of
surveying in the Caribbean Sea, all equipment will be recovered, and
the vessel will return to Puerto Limon on approximately March 11, 2008.
The vessel will then transit through the Panama Canal, likely taking on
fuel in Panama. The second part of the survey will commence in the
Pacific Ocean on approximately March 19, 2008 from Puerto Caldera,
Costa Rica. The Pacific survey is estimated to last approximately 25
days. The vessel is scheduled to arrive at Puerto Caldera on April 13,
2008. The exact dates of the activities depend upon logistics, as well
as weather conditions and/or the need to repeat some lines if data
quality is substandard.
The Central American SubFac survey will encompass the area from
9.6[deg]-14[deg] N., 82[deg]-83.8[deg] W. in the Caribbean Sea and the
area 8[deg]-11.5[deg] N., 83.6[deg]-88[deg] W. in the Pacific Ocean
(see Figure 1 in the application). Water depths in the survey area
range from less than 100 m (328 ft) to greater than 2,500 m (8,202 ft).
The marine seismic survey will consist of approximately 2,149 km
(1,335 mi) of unique survey lines: 753 km (468 mi) in the Caribbean and
1,396 km (867 mi) in the Pacific (see Table 1 in the application). With
the exception of two lines (D and E) located in shallow to
intermediate-depth water, all lines will be shot twice, once at
approximately a 50-m (164 ft; 20-s) shot spacing for multichannel
seismic data and once at approximately a 200-m (656 ft; 80-s) shot
spacing for OBS refraction data, for a total of approximately 3,980 km
(2,473 mi) of survey lines (see Table 1 in the application). The
approximate numbers of line kilometers expected to be surveyed in the
Pacific and Caribbean in three different water depth categories are
shown in Table 2 of the application. There will be additional
operations associated with equipment testing, startup, line changes,
and repeat coverage of any areas where initial data quality is
substandard. There will be an additional 77 km (48 mi) of survey effort
in the Pacific Ocean around Culebra off Nicoya Peninsula not reflected
in Table 1 of L-DEO's application. These additional six transect lines
will occur in water greater than 100 m (328 ft) deep, will not add any
additional days to the cruise, and are not expected to increase the
number of takes by harassment (see below).
The New Horizon will be the dedicated OBS vessel during the Pacific
part of the survey and will deploy and retrieve the OBSs. A combination
of 85 OBSs (150 total deployments) will be used during the project. A
total of 60 OBS deployments will take place in the Caribbean (from the
Langseth), and 90 deployments will take place in the Pacific from the
New Horizon.
In addition to the operations of the airgun array, a 12-kHz Simrad
EM120 multibeam echosounder will be operated from the Langseth
continuously throughout the cruise. Also, a 3.5-kHz sub-bottom profiler
(SBP) will be operated by the Langseth during most of the survey and
during normal operations by the New Horizon.
A more detailed description of the authorized action, including
vessel and acoustic source specifications, was included in the proposed
IHA notice (72 FR 71625, December 18, 2007).
Safety Radii
L-DEO estimated the safety radii around their operations using a
model and by adjusting the model results based on empirical data
gathered in the Gulf of Mexico in 2003. Additional information
regarding safety radii in general, how the safety radii were
calculated, and how the empirical measurements were used to correct the
modeled numbers may be found in NMFS' proposed IHA notice (72 FR 71625,
December 18, 2007) and Section I and Appendix A of L-DEO's application.
Using the modeled distances and various correction factors, Table 1
outlines the distances at which three rms sound levels (190 dB, 180 dB,
and 160 dB) are expected to be received from the various airgun
configurations in shallow, intermediate, and deep water depths.
----------------------------------------------------------------------------------------------------------------
Predicted RMS Distances (m)
Source and Volume Tow Depth (m) Water Depth -----------------------------------------------
190 dB 180 dB 160 dB
----------------------------------------------------------------------------------------------------------------
Single Bolt airgun 40 in\3\ 9 Deep 12 40 385
Intermediate 18 60 578
Shallow 150 296 1050
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[[Page 9528]]
4 strings 36 airguns 6600 in\3\ 9 Deep 300 950 6000
Intermediate 450 1425 6667
Shallow 2182 3694 8000
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4 strings 36 airguns 6600 in\3\ 12 Deep 340 1120 7400
Intermediate 510 1680 8222
Shallow 2473 4356 9867
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Table 1. Predicted distances to which sound levels [gteqt]190, 180, and 160 dB re 1 microPa might be received in
shallow (<100 m; 328 ft), intermediate (100-1,000 m; 328-3,280 ft), and deep (>1,000 m; 3,280 ft) water during
the Central American SubFac survey.
Comments and Responses
A notice of receipt of the L-DEO application and proposed IHA was
published in the Federal Register on December 18, 2007 (72 FR 71625).
During the comment period, NMFS received comments from the Marine
Mammal Commission (MMC). Following are the comments from the MMC and
NMFS' responses.
MMC Comment 1: The MMC recommends that observations be made during
all ramp-up procedures to gather data regarding its effectiveness as a
mitigation measure.
Response: The IHA requires that marine mammal observers (MMOs) on
the Langseth make observations for 30 minutes prior to ramp-up, during
all ramp-ups, and during all daytime seismic operations and record the
following information when a marine mammal is sighted:
(i) species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc., and including responses to ramp-up), and
behavioral pace; and
(ii) time, location, heading, speed, activity of the vessel
(including number of airguns operating and whether in state of ramp-up
or power-down), sea state, visibility, cloud cover, and sun glare.
These requirements should provide information regarding the
effectiveness of ramp-up as a mitigation measure, provided animals are
detected during ramp-up.
MMC Comment 2: The MMC recommends that the monitoring period prior
to the initiation of seismic activities and to the resumption of airgun
activities after a power-down be extended to one hour.
Response: As the MMC points out, several species of deep-diving
cetaceans are capable of remaining underwater for more than 30 minutes.
However, for the following reasons, NMFS believes that 30 minutes is an
adequate length for the monitoring period prior to the start-up of
airguns: (1) because the Langseth is required to ramp-up, the time of
monitoring prior to start-up of any but the smallest array is
effectively longer than 30 minutes (i.e., ramp-up will begin with the
smallest gun in the array and airguns will be added in a sequence such
that the source level of the array will increase in steps not exceeding
approximately 6 dB per 5-min period over a total duration of 20-40
min); (2) in many cases MMOs are making observations during times when
sonar is not being operated and will actually be observing the area
prior to the 30-min observation period anyway; (3), many of the species
that may be exposed do not stay underwater more than 30 minutes; and
(4) all else being equal and if a deep diving individual happened to be
in the area in the short time immediately prior to the pre-start-up
monitoring, if an animal's maximum underwater time is 45 minutes, there
is only a 1 in 3 chance that its last random surfacing would be prior
to the beginning of the required 30-min monitoring period.
MMC Comment 3: The MMC recommends that NMFS provide additional
justification for its proposed determination that the planned
monitoring program will be sufficient to detect, with a high level of
certainty, all marine mammals within or entering the identified safety
radii.
Response: The Langseth is utilizing a team of trained MMOs to both
visually monitor from the high observation tower of the Langseth and to
conduct passive acoustic monitoring (PAM). This monitoring, along with
the required mitigation measures (see below), will result in the least
practicable adverse impact on the affected species or stocks and will
result in a negligible impact on the affected species or stocks.
When stationed on the observation platform of the Langseth, the eye
level will be approximately 17.8 m (58.4 ft) above sea level, so the
visible distance (in good weather) to the horizon is 8.9 nm (16.5 km;
the largest safety radii is 2.4 nm, 4.4 km). Big eyes are most
effective at scanning the horizon (for blows), while 7 X 50 reticle
binoculars are more effective closer in (MMOs also use a naked eye
scan). Night vision devices (NVDs) will be used in low light
situations. Additionally, MMOs will have a good view in all directions
around the entire vessel. Also, nearly 80 percent of the survey
transect lines are in intermediate or deep water depths, where the
safety radii are all less than 1 nm (1.9 km).
In some cases, particularly in shallow water, chase boats will be
deployed, if practicable. The primary mission of the chase boat is to
warn boats that the seismic vessel is approaching and thus the boat
will be in front of the seismic vessel (generally about 3.7 km, 2 nm).
The plan is to have one MMO on the chase boat, who will advise the
Langseth of the presence of marine mammals in the operating area when
forward of the vessel and check for injured animals when aft of the
vessel.
Theoretical detection distance of this PAM system is 10s of
kilometers. The PAM is operated both during the day and at night.
Though it depends on the lights on the ship, the sea state, and thermal
factors, MMOs estimated that visual detection is effective out to
between 150 and 250 m (492 and 820 ft) using NVDs and about 30 m (98.4
ft) with the naked eye. However, the PAM operates equally as
effectively at night as during the day, especially for sperm whales and
dolphins.
MMC Comment 4: The MMC recommends that NMFS take steps to ensure
that the planned monitoring program will be sufficient to detect, with
reasonable certainty, all marine mammals within or entering the
identified safety zones.
Response: Based on the information provided in the previous comment
(above) and the following information, NMFS believes that the planned
monitoring program will be sufficient to detect (using visual detection
and PAM), with reasonable certainty, most marine mammals within or
entering identified safety zones. This monitoring,
[[Page 9529]]
along with the required mitigation measures (see below), will result in
the least practicable adverse impact on the affected species or stocks
and will result in a negligible impact on the affected species or
stocks.
As mentioned above, the platform of the Langseth is high enough
that, in good weather, MMOs can see out to 16.5 km (8.9 nm). The PAM
has reliable detection rates out to 3 km (1.6 nm) and more limited
ability out to 10s of km. The largest 180-dB safety radii (3.7 and 4.4
km, 2 and 2.4 nm), which is the radii within which the Langseth is
required to shut down if a marine mammal enters, are found when the 36-
gun array is operating in shallow water at 9 and 12 m (29.5 and 39 ft)
tow depths, respectively. The species most likely to be encountered in
the shallow waters off the coasts of Nicaragua and Costa Rica are
bottlenose and pantropical spotted dolphins, which have relatively
larger group sizes (2-15 animals for bottlenose dolphins but even
higher in some areas of the survey, 20 or more animals per group for
pantropical spotted dolphins), are not cryptic at the surface, and have
relatively short dive times (5-12 minutes for bottlenose), all which
generally make them easier to visually detect. Furthermore, the
vocalizations of these species are easily detected by the PAM. Also, as
mentioned above, MMOs on chase boats will sometimes be used in addition
to visual monitoring from the seismic vessels and PAM. During the
Maurice Ewing cruise in the GOM in 2003, MMOs detected marine mammals
at a distance of approximately 10 km (5.4 nm) from the vessel and
identified them to species level at approximately 5 km (2.7 nm) from
the vessel, though the bridge of that vessel was only 11 m (36 ft)
above the water (vs. the Langseth, which is more than 17 m (55.8 ft)
above sea level). All of the 180-dB safety radii for other water depths
and tow depths and for the single 40 in\3\ airgun to be used during
ramp-ups and power-downs (see below) are less than 2 km (1.1 nm).
The likelihood of visual detection at night is significantly lower
than during the day, though the PAM remains just as effective at night
as during the day. However, the Langseth will not be starting up the
airguns unless the safety range is visible for the entire 30 minutes
prior (i.e., not an night), and therefore in all cases at night, the
airguns will already be operating, which NMFS believes will cause many
cetaceans to avoid the vessel, which therefore will reduce the number
likely to come within the safety radii. Additionally, all of the safety
radii in intermediate and deep water depths are smaller than 3 km (1.6
nm) and fall easily within the reliable detection capabilities of the
PAM.
Description of Marine Mammals in the Activity Area
A total of 35 marine mammal species are known to or may occur in
the study area off Central America, including 26 odontocete (dolphins
and small and large toothed whales) species, six mysticete (baleen
whales) species, two pinniped species, and the West Indian manatee. Six
of the species that may occur in the project area are listed under the
U.S. Endangered Species Act (ESA) as Endangered: the sperm, humpback,
sei, fin, and blue whale and the manatee. The West Indian manatee is
under the jurisdiction of the U.S. Fish and Wildlife Service (USFWS)
and therefore is not considered further in this analysis. L-DEO
requested and has been authorized to take 26 of these species. The
remaining nine species are not expected to be encountered during the
survey.
Table 2 outlines the species, their habitat and abundance in the
project area, and the estimated and authorized take levels. Additional
information regarding the status and distribution of the marine mammals
in the area and how the densities were calculated was included in the
notice of the proposed IHA (72 FR 71625, December 18, 2007) and may be
found in L-DEO's application.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Abun. in NW Auth Take in Carib.
Species Habitat Atlantic\1\ Abun. in ETP\2\ Sea Auth Take in ETP
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontocetes
Sperm whale (C,P)(Physeter Pelagic 13,190\a\ 26,053\b\ 3 71
macrocephalus) 4,804
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Pygmy sperm whale (C*,P)(Kogia Deeper water off shelf 395\c\ N.A. 0 0
breviceps)
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Dwarf sperm whale (C*,P) (Kogia Deeper waters off shelf 395\c\ 11,200\d\ 0 856
sima)
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Cuvier's beaked whale (C*,P) Pelagic 3,513\e\ 20,000 0 302
(Ziphius cavirostris) 90,725\bb\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Longman's beaked whale (P?) Pelagic N.A. 291\bb\ 0 9
(Indopacetus pacificus)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy beaked whale (P) (Mesoplodon Pelagic N.A. 25,300\f\ 0 0
peruvianus) 32,678\cc\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gingko-toothed beaked whale (P?) Pelagic N.A. 25,300\f\ 0 0
(Mesoplodon ginkgodens) 32,678\cc\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gervais' beaked whale Pelagic N.A. N.A. 4 0
(C?)(Mesoplodon europaeus)
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Blainville's beaked whale (C*,P) Pelagic N.A. 25,300\f\ 0 29
(Mesoplodon densirostris) 32,678\cc\
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[[Page 9530]]
Rough-toothed dolphin (C?,P) Mainly pelagic 2,223\g\ 145,900 9 954
(Steno bredanensis)
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Tucuxi (C) (Sotalia fluviatilis) Freshwater and coastal 49\h\ N.A. 0 0
waters 705\i\
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Bottlenose dolphin (C,P) (Tursiops Coastal, shelf and 43,951\j\ 243,500 389 2,380
truncatus) pelagic 81,588\k\
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Pantropical spotted dolphin (C?,P) Coastal and pelagic 4,439 2,059,100 37 7,560
(Stenella attenuata)
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Atlantic spotted dolphin (C) Coastal and shelf 50,978 N.A. 440 0
(Stenella frontalis)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spinner dolphin (C*,P) (Stenella Coastal and pelagic 11,971\g\ 1,651,100 0 7,856
longirostris)
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Costa Rican spinner dolphin (P) Coastal N.A. N.A. 0 3,358
(Stenella l. centroamericana)
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Clymene dolphin (C?) (Stenella Pelagic 6,086 N.A. 29 0
clymene)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Striped dolphin (C*,P) (Stenella Coastal and pelagic 94,462 1,918,000 31 8,110
coeruleoalba)
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Short-beaked common Shelf and pelagic N.A. 3,093,300 0 14,045
dolphin (P) (Delphinus delphis)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fraser's dolphin (C*,P) Pelagic 726\g\ 289,300 0 144
(Lagenodelphis hosei)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Risso's dolphin (C*,P) (Grampus Shelf and pelagic 20,479 175,800 0 651
griseus)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Melon-headed whale (C*,P) Pelagic 3,451\g\ 45,400 0 1,315
(Peponocephala electra)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy killer whale (C*,P) (Feresa Pelagic 6\l\ 38,900 0 231
attenuata) 408\g\
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False killer whale (C*,P) Pelagic 1,038\g\ 39,800 0 479
(Pseudorca crassidens)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale (C,P) (Orcinus orca) Coastal 133\g\ 8,500 10 17
6,600\m\
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Short-finned pilot whale (C,P) Pelagic 31,139\n\ 160,200\n\ 36 3,717
(Globicephala macrorhynchus)
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Humpback whale (C?,P) (Megaptera Mainly nearshore 10,400\o\ NE Pacific 1,391\q\; 1 4
novaeangliae) waters and banks 11,570\p\ SE Pacific ~2,900\r\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke whale (C*,P) (Balaenoptera Coastal 3,618s N.A. 0 0
acutorostrata) 174,000t
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bryde's whale (C?,P) (Balaenoptera Coastal and pelagic 35\g\ 13,000\u\ 3 68
edeni)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sei whale (C*,P) (Balaenoptera Pelagic 12-13,000\v\ N.A. 0 0
borealis)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale (C,P) (Balaenoptera Pelagic 2,814 1,851\q\ 1 0
physalus) 30,000t
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale (C*,P) (Balaenoptera Coastal, shelf, and 320\w\ 1,400 0 4
musculus) pelagic
[[Page 9531]]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sirenian Freshwater and coastal 86\x\ N.A. 0 0
West Indian manatee (C) waters 340\y\
(Trichechus manatus manatus)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pinnipeds
California sea lion (P) (Zalophus Coastal N.A. 237,000-244,000\z\ 0 0
californianus)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gal[aacute]pagos sea lion (P?) Coastal N.A. 30,000\aa\ 0 0
(Zalophus wollebaeki)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 2. The habitat, abundance, and requested take levels of marine mammals that may be encountered during the proposed Central American SubFac seismic
survey off Central America. Note: Abun. = abundance, NWA = Northwest Alantic Ocean, P = may occur off Pacific coast of proposed project area, C = may
occur off Caribbean coast of proposed project area, * = very unlikely to occur in proposed project area, ? = potentially possible but somewhat
unlikely to occur in proposed project area, N.A. = Not available or not applicable.
\1\ For cetaceans, abundance estimates are given for U.S. Western North Atlantic stocks (Waring et al. 2006) unless otherwise noted.
\2\ Abundance estimates for the ETP from Wade and Gerrodette (1993) unless otherwise indicated.
\a\ g(o) corrected total estimate for the Northeast Atlantic, Faroes-Iceland, and the U.S. east coast (Whitehead 2002).
\b\ Whitehead 2002.
\c\ This estimate is for Kogia sp.
\d\ This abundance estimate is mostly for K. sima but may also include some K. breviceps.
\e\ This estimate is for Mesoplodon and Ziphius spp.
\f\ This estimate includes all species of the genus Mesoplodon from Wade and Gerrodette (1993).
\g\ This estimate is for the northern Gulf of Mexico.
\h\ Estimate from a portion of Cayos Miskito Reserve, Nicaragua (Edwards and Schnell 2001).
\i\ Estimate from the Canan[eacute]ia estuarine region of Brazil (Geise et al. 1999).
\j\ Estimate for the Western North Atlantic coastal stocks (North Carolina (summer), South Carolina, Georgia, Northern Florida, and Central Florida).
\k\ Estimate for the for the Western North Atlantic offshore stock.
\l\ Based on a single sighting.
\m\ Estimate for Icelandic and Faroese waters (Reyes 1991).
\n\ This estimate is for G. macrorhynchus and G. melas.
\o\ Estimate for the entire North Atlantic (Smith et al. 1999).
\p\ This estimate is for the entire North Atlantic (Stevick et al. 2001, 2003).
\q\ Carretta et al. 2007.
\r\ Felix et al. 2005.
\s\ This estimate is for the Canadian East Coast stock.
\t\ Estimate is for the North Atlantic (IWC 2007a).
\u\ This estimate is mainly for Balaenoptera edeni but may include some B. borealis.
\v\ Abundance estimate for the North Atlantic (Cattanach et al. 1993).
\w\ Minimum abundance estimate (Sears et al. 1990).
\x\ Antillean Stock in Puerto Rico only.
\y\ Antillean Stock in Belize (Reeves et al. 2002).
\z\ Estimate for the U.S. stock (Carretta et al. 2007).
\aa\ Reeves et al. 2002.
\bb\ Ferguson and Barlow 2001 in Barlow et al. 2006.
\cc\ This estimate includes all species of the genus Mesoplodon (Ferguson and Barlow 2001 in Barlow et al. 2006).
Potential Effects on Marine Mammals
The effects of sounds from airguns might include one or more of the
following: tolerance, masking of natural sounds, behavioral
disturbances, and at least in theory, temporary or permanent hearing
impairment, or non-auditory physical or physiological effects
(Richardson et al., 1995; Gordon et al., 2004; Nowacek et al., 2007).
However, it is unlikely that there would be any cases of temporary or
especially permanent hearing impairment or any significant non-auditory
physical or physiological effects. Also, behavioral disturbance is
expected to be limited to relatively short distances.
The notice of the proposed IHA (72 FR 71625, December 18, 2007)
included a discussion of the effects of sounds from airguns on
mysticetes, odontocetes, and pinnipeds, including tolerance, masking,
behavioral disturbance, hearing impairment, and other non-auditory
physical effects. Additional information on the behavioral reactions
(or lack thereof) by all types of marine mammals to seismic vessels can
be found in Appendix C (e) of L-DEO's application.
The notice of the proposed IHA also included a discussion of the
potential effects of the bathymetric sonar and the sub-bottom profiler.
Because of the shape of the beams of these sources and their power,
NMFS believes it unlikely that marine mammals will be exposed to either
the bathymetric sonar or the SBP at levels at or above those likely to
cause harassment. Further, NMFS believes that the brief exposure of
cetaceans or pinnipeds to few signals from the multi-beam bathymetric
sonar system are not likely to result in the harassment of marine
mammals.
Estimated Take by Incidental Harassment
The notice of the proposed IHA (72 FR 71625, December 18, 2007)
included an in-depth discussion of the methods used to calculate the
densities of the marine mammals in the area of the seismic survey and
the take estimates. Additional information was included in L-DEO's
application. A summary is included here.
All anticipated takes authorized by this IHA are Level B harassment
only, involving temporary changes in behavior. The two far right
columns in Table 2, ``Auth Take in Carib. Sea'' and ``Auth Take in
ETP'', display the numbers for which take is authorized in each ocean
basin. Take calculations were based on maximum exposure estimates
(based on maximum density estimates) vs. best estimates and are based
on the 160-dB isopleth of a larger array of airguns. Given these
considerations, the predicted number of marine mammals that might be
exposed to sounds 160 dB may be somewhat overestimated.
[[Page 9532]]
Extensive marine mammal surveys have been conducted in the eastern
tropical Pacific over numerous years (e.g., Polacheck, 1987; Wade and
Gerrodette, 1993; Kinsey et al., 1999, 2000, 2001; Ferguson and Barlow,
2001; Smultea and Holst, 2003; Jackson et al., 2004; Holst et al.,
2005a; May-Collado et al., 2005). Therefore, for the Pacific portion of
the proposed seismic survey, marine mammal density data were readily
available. The most comprehensive data available for the region
encompassing the proposed survey area are from Ferguson and Barlow
(2001) and Holst et al. (2005a).
For the Caribbean portion of the Central American SubFac program,
we were unable to find published data on marine mammal densities in or
immediately adjacent to the seismic survey area. The closest
quantitative surveys were conducted in the southeast Caribbean (Swartz
and Burks, 2000; Swartz et al., 2001; Smultea et al., 2004). Most of
the survey effort by Swartz and Burks (2000) and Swartz et al. (2001)
took place during March and April near the islands on the east side of
the Caribbean Sea and near the north and northeast coasts of Venezuela
in water depths < 1,000 m (3,280 ft). Survey data from Smultea et al.
(2004) were collected north of Venezuela during April-June in
association with a previous L-DEO seismic survey. The L-DEO survey will
occur from February-March in the western Caribbean Sea, a location and
time of year in which the species densities are likely different from
those during the above-mentioned surveys in the southeast Caribbean,
but these surveys are the best available data at this time.
Except for dwarf sperm whales, the per-species take estimates fall
within 3 percent (dwarf sperm whale takes are 7.64 percent) of the
numbers estimated to be present during a localized survey in the
Pacific Ocean off the coasts of Costa Rica and Nicaragua, and the
affected species range far beyond the Pacific Ocean (i.e., the
abundance of the species is notably larger). Therefore, NMFS believes
that the estimated take numbers for these affected species are
relatively small.
Similarly, the per-species take estimates are less than 1 percent
(except killer (7.52 percent) and Bryde's (8.57 percent) whales) of the
numbers estimated to be present during a localized survey in the
Caribbean Sea off the coasts of Costa Rica and Nicaragua, and the
species range far beyond the Caribbean (i.e., the abundance of the
species is notably larger). Therefore, NMFS believes that the estimated
take numbers for these species are relatively small.
No pinnipeds are expected to be encountered in the Caribbean, and
the likelihood of encountering sea lions or other pinnipeds in the
Pacific study area is also very low. No take of any pinniped species is
authorized.
Potential Effects on Habitat
A detailed discussion of the potential effects of this action on
marine mammal habitat, including physiological and behavioral effects
on marine fish and invertebrates, was included in the notice of the
proposed IHA (72 FR 71625, December 18, 2007). Based on the discussion
in the proposed IHA and the nature of the activities (limited
duration), the authorized operations are not expected to have any
habitat-related effects that could cause significant or long-term
consequences for individual marine mammals or their populations or
stocks. Similarly, any effects to food sources are expected to be
negligible.
Monitoring
Vessel-based Visual Monitoring
Vessel-based marine mammal visual observers (MMVOs) will be based
aboard the seismic source vessel and will watch for marine mammals near
the vessel during daytime airgun operations and during start-ups of
airguns at night. MMVOs will also watch for marine mammals near the
seismic vessel for at least 30 minutes prior to the start of airgun
operations after an extended shutdown of the airguns. When feasible,
MMVOs will also make observations during daytime periods when the
seismic system is not operating for comparison of animal abundance and
behavior. Based on MMVO observations, airguns will be powered down, or
if necessary, shut down completely (see below), when marine mammals are
detected within or about to enter a designated safety radius. The MMVOs
will continue to maintain watch to determine when the animal(s) are
outside the safety radius, and airgun operations will not resume until
the animal has left that zone. The safety radius is a region in which a
possibility exists of adverse effects on animal hearing or other
physical effects.
During seismic operations off Central America, at least three
observers will be based aboard the Langseth. MMVOs will be appointed by
L-DEO with NMFS concurrence. At least one MMVO, and when practical two,
will monitor the safety radii for marine mammals during daytime
operations and nighttime startups of the airguns. MMVO(s) will be on
duty in shifts of duration no longer than 4 hours. The crew will also
be instructed to assist in detecting marine mammals and implementing
mitigation requirements (if practical).
The Langseth is a suitable platform for marine mammal observations.
When stationed on the observation platform, the eye level will be
approximately 17.8 m (58.4 ft) above sea level, and the observer will
have a good view around the entire vessel. During daytime, the MMVO(s)
will scan the area around the vessel systematically with reticle
binoculars (e.g., 7x50 Fujinon), Big-eye binoculars (25x150), and with
the naked eye. During darkness, NVDs will be available (ITT F500 Series
Generation 3 binocular-image intensifier or equivalent). Laser
rangefinding binoculars (Leica LRF 1200 laser rangefinder or
equivalent) will be available to assist with distance estimation.
Passive Acoustic Monitoring
PAM will take place to complement the visual monitoring program.
Visual monitoring typically is not effective during periods of bad
weather or at night, and even with good visibility, is unable to detect
marine mammals when they are below the surface or beyond visual range.
Acoustic monitoring can be used in addition to visual observations to
improve detection, identification, localization, and tracking of
cetaceans. It is only useful when marine mammals call, but it can be
effective either by day or by night and does not depend on good
visibility. The acoustic monitoring will serve to alert visual
observers (if on duty) when vocalizing cetaceans are detected. It will
be monitored in real time so visual observers can be advised when
cetaceans are detected. When bearings (primary and mirror-image) to
calling cetacean(s) are determined, the bearings will be relayed to the
visual observer to help him/her sight the calling animal(s).
SEAMAP (Houston, Texas) will be used as the primary acoustic
monitoring system. This system was also used during several previous L-
DEO seismic cruises (e.g., Smultea et al., 2004, 2005; Holst et al.,
2005a,b). A description of the PAM system was given in the notice of
the proposed IHA (72 FR 71625, December 18, 2007).
While the Langseth is in the seismic survey area, the towed
hydrophone array will be monitored 24 hours per day while at the survey
area during airgun operations and also during most periods when the
Langseth is underway with the airguns not operating. One MMO will
monitor the acoustic detection system at any one time, by listening to
the signals from two
[[Page 9533]]
channels via headphones and/or speakers and watching the real time
spectrographic display for frequency ranges produced by cetaceans. MMOs
monitoring the acoustical data will be on shift for 1-6 hours. All MMOs
are expected to rotate through the PAM position, although the most
experienced with acoustics will be on PAM duty more frequently.
When a cetacean vocalization is detected, the acoustic MMO will, if
visual observations are in progress, contact the MMVO immediately to
alert him/her to the presence of the vocalizing marine mammal(s). The
information regarding the call will be entered into a database. The
data to be entered include an acoustic encounter identification number,
whether it was linked with a visual sighting, date, time when first and
last heard and whenever any additional information was recorded,
position and water depth when first detected, bearing if determinable,
species or species group (e.g., unidentified dolphin, sperm whale),
types and nature of sounds heard (e.g., clicks, continuous, sporadic,
whistles, creaks, burst pulses, strength of signal, etc.), and any
other notable information. The acoustic detection can also be recorded
for further analysis.
MMVO Data and Documentation
MMVOs will record data to estimate the numbers of marine mammals
exposed to various received sound levels and to document any apparent
disturbance reactions or lack thereof. Data will be used to estimate
the numbers of mammals potentially ``taken'' by harassment. They will
also provide information needed to order a power-down or shutdown of
airguns when marine mammals are within or near the relevant safety
radius. When a sighting is made, the following information about the
sighting will be recorded:
(1) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc. and including responses to ramp-up), and
behavioral pace.
(2) Time, location, heading, speed, activity of the vessel
(including number of airguns operating and whether in state or ramp-up,
power-down, or full power), sea state, visibility, cloud cover, and sun
glare.
The data listed under (2) will also be recorded at the start and
end of each observation watch and during a watch, whenever there is a
change in one or more of the variables.
All mammal observations, as well as information regarding airgun
power down and shutdown, will be recorded in a standardized format.
Data accuracy will be verified by the MMVOs at sea, and preliminary
reports will be prepared during the field program and summaries
forwarded to the operating institution's shore facility and to NSF
weekly or more frequently. MMVO observations will provide the following
information:
(1) The basis for decisions about powering down or shutting down
airgun arrays.
(2) Information needed to estimate the number of marine mammals
potentially 'taken by harassment', which must be reported to NMFS.
(3) Data on the occurrence, distribution, and activities of marine
mammals in the area where the seismic study is conducted.
(4) Data on the behavior and movement patterns of marine mammals
seen at times with and without seismic activity.
Mitigation
Mitigation and monitoring measures proposed to be implemented for
the proposed seismic survey have been developed and refined during
previous L-DEO seismic studies and associated environmental assessments
(EAs), IHA applications, and IHAs. The mitigation and monitoring
measures described herein represent a combination of the procedures
required by past IHAs for other similar projects and on recommended
best practices in Richardson et al. (1995), Pierson et al. (1998), and
Weir and Dolman (2007). The measures are described in detail below.
Required mitigation measures include: (1) speed or course
alteration, provided that doing so will not compromise operational
safety requirements; (2) power-down procedures; (3) shutdown
procedures; (4) ramp-up procedures; and (5) minimizing approaches to
slopes and submarine canyons, if possible, because of sensitivity of
beaked whales.
Speed or Course Alteration - If a marine mammal is detected outside
the safety radius but is likely to enter it based on relative movement
of the vessel and the animal, then if safety and scientific objectives
allow, the vessel speed and/or course will be adjusted to minimize the
likelihood of the animal entering the safety radius. Major course and
speed adjustments are often impractical when towing long seismic
streamers and large source arrays, thus for surveys involving large
sources, alternative mitigation measures are required.
Power-down Procedures - A power-down involves reducing the number
of operating airguns, typically to a single airgun (e.g., 40 in\3\), to
minimize the safety radius, so that marine mammals are no longer in or
about to enter this zone. A power-down of the airgun array to a reduced
number of operating airguns may also occur when the vessel is moving
from one seismic line to another. The continued operation of at least
one airgun is intended to alert marine mammals to the presence of the
seismic vessel in the area.
If a marine mammal is detected outside the safety radius but is
likely to enter it, and if the vessel's speed and/or course cannot be
changed, the airguns will be powered down to a single airgun before the
animal is within the safety radius. Likewise, if a mammal is already
within the safety radius when first detected, the airguns will be
powered down immediately. If a marine mammal is detected within or near
the smaller safety radius around that single airgun (see Table 1), all
airguns will be shutdown (see next subsection).
Following a power down, airgun activity will not resume until the
marine mammal is outside the safety radius for the full array. The
animal will be considered to have cleared the safety radius if it:
(1) Is visually observed to have left the safety radius; or
(2) Has not been seen within the safety radius for 15 minutes in
the case of small odontocetes and pinnipeds; or
(3) Has not been seen within the safety radius for 30 minutes in
the case of mysticetes and large odontocetes, including sperm, pygmy
sperm, dwarf sperm, killer, and beaked whales.
Following a power-down and subsequent animal departure as above,
the airgun array will resume operations following ramp-up procedures
described below.
Shutdown Procedures - The operating airgun(s) will be shutdown if a
marine mammal is detected within the safety radius of a single 40 in3
airgun while the airgun array is at full volume or during a power down.
Airgun activity will not resume until the marine mammal has cleared the
safety radius or until the MMVO is confident that the animal has left
the vicinity of the vessel. Criteria for judging that the animal has
cleared the safety radius will be as described in the preceding
subsection.
Ramp-up Procedures - A ramp-up procedure will be followed when the
airgun array begins operating after a specified-duration period without
[[Page 9534]]
airgun operations or when a power-down has exceeded that period. For
the present cruise, this period would be approximately 8 min. This
period is based on the modeled 180-dB radius for the 36-airgun array
(see Table 1) in relation to the planned speed of the Langseth while
shooting in deep water. Similar periods (approximately 8-10 min) were
used during previous L-DEO surveys.
Ramp-up from a state of no airgun operations will begin with the
smallest airgun in the array (40 in\3\). Airguns will be added in a
sequence such that the source level of the array will increase in steps
not exceeding 6 dB per 5-minute period over a total duration of
approximately 20-40 min. Ramp-up from a reduced power state, such as
during maintenance of an airgun string while the remaining string
continues to fire would include the start-up of the returned string.
During ramp-up, the MMVOs will monitor the safety radius, and if marine
mammals are sighted, a course/speed change, power-down, or shutdown
will be implemented as though the full array were operational.
Initiation of ramp-up procedures from shutdown requires that the
full safety radius must be visible by the MMVOs, whether conducted in
daytime or nighttime. This requirement will effectively preclude start
ups at night or in thick fog because the outer part of the safety
radius for that array will not be visible during those conditions.
Ramp-up is allowed from a power-down under reduced visibility
conditions only if at least one airgun (e.g., 40 in\3\ or similar ) has
operated continuously throughout the survey without interruption, on
the assumption that marine mammals will be alerted to the approaching
seismic vessel by the sounds from the single airgun and could move away
if they choose. Ramp-up of the airguns will not be initiated if a
marine mammal is sighted within or near the applicable Safety radius
during the day or close to the vessel at night.
Minimize Approach to Slopes and Submarine Canyons - Although
sensitivity of beaked whales to airguns is not known, they appear to be
sensitive to other sound sources (e.g., mid-frequency sonar). Beaked
whales tend to concentrate in continental slope areas and in areas
where there are submarine canyons. There are no submarine canyons
within or near the study area. Three of the transect lines are on the
continental slope, which accounts for only a small portion of the
proposed study area (207 km; 128.6 mi) and a minimal amount of time (30
hours).
Reporting
A report will be submitted to NMFS within 90 days after the end of
the cruise. The report will describe the operations that were conducted
and sightings of marine mammals near the operations. The report will be
submitted to NMFS, providing full documentation of methods, results,
and interpretation pertaining to all monitoring. The 90-day report will
summarize the dates and locations of seismic operations, all 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)
Pursuant to section 7 of the ESA, NSF has consulted with the NMFS,
Office of Protected Resources, Endangered Species Division on this
seismic survey. NMFS has also consulted internally pursuant to section
7 of the ESA on the issuance of an IHA under section 101(a)(5)(D) of
the MMPA for this activity. NMFS has issued a Biological Opinion
(BiOp), which concluded that the proposed action and issuance of an IHA
are not likely to jeopardize the continued existence of blue, fin,
humpback and sperm whales and green, hawksbill, leatherback,
loggerhead, and olive ridley sea turtles. The BiOp also concluded that
the proposed action would have no effect on critical habitat since none
has been designated within the action area. The BiOp also made a not
likely to be adversely affected finding for sei whales, Kemp's ridley
sea turtles, and elkhorn and staghorn corals. An incidental take
statement (ITS) will be issued for the take of blue, fin, humpback, and
sperm whales and green, hawksbill, leatherback, loggerhead, and olive
ridley sea turtles. Relevant Terms and Conditions of the ITS have been
incorporated into the IHA.
NSF and L-DEO made a ``no effects'' determination for this seismic
survey regarding the West Indian manatee. The USFWS concurred with this
determination since activities would occur at least 8 km (5 mi) from
shore in water depths greater than 20 m (65.6 ft). Also, no support
vessels would be sent from shore during the cruise. Based on these
parameters, a USFWS consultation was not required for this action.
National Environmental Policy Act (NEPA)
NSF prepared an Environmental Assessment of a Marine Geophysical
Survey by the R/V Marcus G. Langseth off Central America, January-March
2008. NMFS has adopted NSF's EA and issued a Finding of No Significant
Impact for the issuance of the IHA.
Determinations
NMFS has determined that the impact of conducting the seismic
survey in the Pacific Ocean and Caribbean Sea off Central America may
result, at worst, in a temporary modification in behavior (Level B
Harassment) of small numbers of 26 species of cetaceans. Further, this
activity is expected to result in a negligible impact on the affected
species or stocks. The provision requiring that the activity not have
an unmitigable adverse impact on the availability of the affected
species or stock for subsistence uses does not apply for this action.
This negligible impact determination is supported by: (1) the
likelihood that, given sufficient notice through relatively slow ship
speed, marine mammals are expected to move away from a noise source
that is annoying prior to it becoming potentially injurious; (2) the
fact that marine mammals would have to be closer than 40 m (131 ft) in
deep water, 60 m (197 ft) at intermediate depths, or 296 m (971 ft) in
shallow water when a single airgun is in use from the vessel to be
exposed to levels of sound (180 dB) believed to have even a minimal
chance of causing TTS; (3) the fact that marine mammals would have to
be closer than 950 m (0.5 nm) in deep water, 1,425 m (0.8 nm) at
intermediate depths, and 3,694 m (2 nm) in shallow water when the full
array is in use at a 9 m (29.5 ft) tow depth from the vessel to be
exposed to levels of sound (180 dB) believed to have even a minimal
chance of causing TTS; (4) the fact that marine mammals would have to
be closer than 1,120 m (0.6 nm) in deep water, 1,680 m (0.9 nm) at
intermediate depths, and 4,356 m (2.4 nm) in shallow water when the
full array is in use at a 12 m (39 ft) tow depth from the vessel to be
exposed to levels of sound (180 dB) believed to have even a minimal
chance of causing TTS; (5) the likelihood that marine mammal detection
ability by trained observers is good at those distances from the
vessel; (6) the use of PAM, which is effective out to 10s of km, will
assist in the detection of vocalizing marine mammals at greater
distances from the vessel; and (7) the incorporation of other required
mitigation measures (i.e., ramp-up, power-down, and shutdown). 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
[[Page 9535]]
avoided through the incorporation of the required mitigation measures.
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, a small percent of any of the
estimated population sizes, and has been mitigated to the lowest level
practicable through incorporation of the measures mentioned previously
in this document.
Authorization
As a result of these determinations, NMFS has issued an IHA to L-
DEO for conducting a marine geophysical survey in the Pacific Ocean and
Caribbean Sea off Central America from February-April, 2008, provided
the previously mentioned mitigation, monitoring, and reporting
requirements are incorporated.
Dated: February 14, 2008.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. E8-3256 Filed 2-20-08; 8:45 am]
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