[Federal Register Volume 68, Number 196 (Thursday, October 9, 2003)]
[Notices]
[Pages 58308-58315]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-25639]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 090903C]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Oceanographic Survey in the Northwest Atlantic Ocean Near Bermuda

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

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

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SUMMARY: NMFS has received an application from the Lamont-Doherty Earth 
Observatory (LDEO) for an Incidental Harassment Authorization (IHA) to 
take small numbers of marine mammals, by harassment, incidental to 
conducting an oceanographic survey in

[[Page 58309]]

the Northwest Atlantic Ocean near Bermuda. Under the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an authorization to LDEO to incidentally take, by harassment, 
small numbers of several species of cetaceans and pinnipeds for a 
limited period of time within the next year.

DATES: Comments and information must be received no later than November 
7, 2003.

ADDRESSES: Comments on the application should be addressed to the 
Acting Chief, Marine Mammal Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service, 1315 East-West Highway, 
Silver Spring, MD 20910-3225, or by telephoning the contact listed 
here. A copy of the application containing a list of the references 
used in this document may be obtained by writing to this address or by 
telephoning the contact listed here. Comments cannot be accepted if 
submitted via e-mail or the Internet.

FOR FURTHER INFORMATION CONTACT: Sarah C. Hagedorn, Office of Protected 
Resources, NMFS, (301) 713-2322, ext 117.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region if certain findings are 
made and either regulations are issued or, if the taking is limited to 
harassment, a notice of a proposed authorization is provided to the 
public for review.
    Permission may be granted if NMFS finds that the taking will have a 
negligible impact on the species or stock(s) and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses and that the permissible methods of 
taking and requirements pertaining to the monitoring and reporting of 
such takings are set forth. NMFS has defined ``negligible impact'' in 
50 CFR 216.103 as ``...an impact resulting from the specified activity 
that cannot be reasonably expected to, and is not reasonably likely to, 
adversely affect the species or stock through effects on annual rates 
of recruitment or survival.''
    Subsection 101(a)(5)(D) of the MMPA established an expedited 
process by which citizens of the United States can apply for an 
authorization to incidentally take small numbers of marine mammals by 
harassment. 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).
    Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
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 July 16, 2003, NMFS received an application from LDEO for the 
taking, by harassment, of several species of marine mammals incidental 
to conducting a seismic survey by the R/V Maurice Ewing within the 
Northwest Atlantic Ocean off the coast of Bermuda near the Bermuda Rise 
area, between 29[deg] and 35[deg] N and between 61[deg] and 68[deg] W, 
during November and early December 2003. These operations will take 
place within the Exclusive Economic Zone (EEZ) of Bermuda and adjacent 
international waters. Clearance to conduct the seismic survey in the 
foreign EEZ has been requested from Bermuda (U.K.). The purpose of this 
project is to determine what physical and chemical changes have been 
imparted to the tectonic plate as a result of the eruption of the 
Bermuda volcano. By understanding what portion of the uplift of the 
seafloor is caused by thermal (temporary) versus chemical (permanent) 
changes to the plate, it will be possible to predict the rate that 
volcanoes in the middle of plates will sink beneath the waves.

Description of the Activity

    The seismic survey will involve a single vessel, the R/V Maurice 
Ewing, which will conduct the seismic work. The Maurice Ewing will 
deploy an array of 20 airguns as an energy source, and a receiving 
system consisting of Ocean Bottom Hydrophones (OBH's), 96 sonobuoys, 
and/or a 6-km (3.2-nm) towed hydrophone streamer. The energy to the 
airgun array is compressed air supplied by compressors on board the 
source vessel. As the airgun array is towed along the survey lines, the 
towed hydrophone streamer or OBH's will receive the returning acoustic 
signals and transfer the data to the on-board processing system. The 
OBH's and sonobuoys will be deployed by the R/V Maurice Ewing.
    All planned geophysical data acquisition activities will be 
conducted by LDEO scientists, with on-board assistance from the 
scientists who have proposed the study. The survey will be conducted in 
the deep ocean depths (1000 m or 3281 ft) of the Bermuda 
Rise. The survey program will consist of approximately 2400 km (1296 
nm) of survey lines. There will be two intersecting seismic reflection 
and refraction lines, each approximately 600 km (324 nm) long. One line 
will be oriented north-south along a magnetic isochron, and the other 
line will be oriented east-west along the presumed track of the 
hotspot. The point of intersection of these two lines will be in close 
vicinity of Bermuda Island. Each of the two lines will be surveyed 
twice. Along each line, the upper crustal structure will be determined 
by acquiring multibeam sonar, multichannel seismic (MCS), and sonobuoy 
refraction data. Then, a linear array of OBH's will be deployed for 
refraction shooting. The specific configuration of the airgun array 
will differ between the MCS and OBH surveys (described later in this 
document). There will be additional operations associated with 
equipment testing, startup, line changes, and repeat coverage of any 
areas where initial data quality is sub-standard.
    The procedures to be used for the 2003 seismic survey will be 
similar to those used during previous seismic surveys by LDEO, e.g., in 
the equatorial Pacific Ocean (Carbotte et al., 1998, 2000). The 
proposed program will use conventional seismic methodology with a towed 
airgun array as the energy source and a towed streamer containing 
hydrophones as the receiver system. In addition, sonobuoys and OBH's 
will also be used at times as the receiver system. In addition, a 
multi-beam bathymetric sonar will be operated from the source vessel 
continuously throughout the entire cruise, and a lower-energy sub-
bottom profiler will also be operated during most of the survey. 
Seismic surveys will likely commence on November 6, 2003, and continue 
until the first week of December, 2003. Exact dates of the activity may 
vary by a few days due to

[[Page 58310]]

weather conditions of the need to repeat some lines if data quality is 
substandard.
    The R/V Maurice Ewing will be used as the source vessel. It will 
tow the 20-airgun array and a streamer containing hydrophones along 
predetermined lines. During seismic acquisition, the vessel will travel 
at 4-5 knots (7.4-9.3 km/hr). During the MCS survey, the airgun array 
to be used will consist of 20 2000-psi Bolt airguns. The standard 20-
gun array will include airguns ranging in chamber volume from 80 to 850 
in\3\, with a total volume of 8,575 in\3\. These airguns will be spaced 
in an approximate rectangle of dimensions of 35 m (115 ft)(across 
track) by 9 m (30 ft)(along track). Seismic pulses will be emitted at 
intervals of approximately 20 seconds. The 20-sec spacing corresponds 
to a shot interval of about 50 m (164 ft). After the line has been 
surveyed using MCS, the hydrophone streamer will be retrieved and OBH's 
will be deployed. During the OBH refraction survey, an augmented 20-gun 
array will be used and configured for a total volume of approximately 
11,000 in3 by changing smaller gun chambers for larger volume chambers 
(ranging from 145 to 875 in\3\) after the completion of the MCS 
reflection lines. Seismic pulses will be emitted at intervals of 240 
seconds during OBH acquisition. LDEO believes that even though the 
augmented 20-gun array will have a total air discharge volume of 
approximately 2400 in\3\ more than the standard 20-gun array, this will 
not significantly increase the source output since the number of guns 
has a greater effect on source output than discharge volume.
    The dominant frequency components for both airgun arrays is 0 - 188 
Hz. The standard 20-airgun array (MCS survey) will have a peak sound 
source level of 255 dB re 1 microPa or 262 dB peak-to-peak (P-P), and 
will be towed at a depth of 7.5 m (24.5 ft). The augmented 20-airgun 
array (OBH survey) will have a peak sound source level of 256 dB re 1 
microPa or 263 dB P-P, and will be towed at a depth of 9.0 m (29.5 ft). 
Because the actual 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. Also, because of the directional nature of the sound from the 
airgun array, the effective source level for sound propagating in near-
horizontal directions will be substantially lower.
    Along with the airgun operations, two additional acoustical data 
acquisition systems will be operated during most or all of the cruise. 
The ocean floor will be mapped with an Atlas Hydrosweep DS-2 multibeam 
15.5-kHz bathymetric sonar, and a 3.5-kHz sub-bottom profiler will also 
be operated along with the multi-beam sonar. These mid-frequency sound 
sources are commonly operated from the Maurice Ewing simultaneous with 
the airgun array.
    The Atlas Hydrosweep is mounted in the hull of the R/V Maurice 
Ewing, and it operates in three modes, depending on the water depth. 
The first is a shallow-water mode when water depth is <400 m (1312.3 
ft). The source output is 210 dB re 1 microPa-m rms and a single 1-
millisec pulse or ``ping'' per second is transmitted, with a beamwidth 
of 2.67 degrees fore-aft and 90 degrees in athwartship. The beamwidth 
is measured to the 3 dB point, as is usually quoted for sonars. The 
other two modes are deep-water modes. The Omni mode is identical to the 
shallow-water mode except that the source output is 220 dB rms. The 
Omni mode is normally used only during start up. The Rotational 
Directional Transmission (RDT) mode is normally used during deep-water 
operation and has a 237-dB rms source output. In the RDT mode, each 
``ping'' consists of five successive transmissions, each ensonifying a 
beam that extends 2.67 degrees fore-aft and approximately 30 degrees in 
the cross-track direction. The five successive transmissions (segments) 
sweep from port to starboard with minor overlap, spanning an overall 
cross-track angular extent of about 140 degrees, with tiny (<1 
millisec) gaps between the pulses for successive 30-degree segments. 
The total duration of the ``ping'', including all 5 successive 
segments, varies with water depth but is 1 millisec in water depths 
<500 m (1640.5 ft) and 10 millisec in the deepest water. For each 
segment, ping duration, is 1/5th of these values or 2/5th for a 
receiver in the overlap area ensonified by two beam segments. The 
``ping'' interval during RDT operations depends on water depth and 
varies from once per second in <500 m (1640.5 ft) water depth to once 
per 15 seconds in the deepest water.
    The sub-bottom profiler is normally operated to provide information 
about the sedimentary features and bottom topography that is 
simultaneously being mapped by the Hydrosweep. The energy from the sub-
bottom profiler is directed downward by a 3.5-kHz transducer mounted in 
the hull of the Maurice Ewing. The output varies with water depth from 
50 watts in shallow water to 800 watts in deep water. Pulse interval is 
1 second but a common mode of operation is to broadcast five pulses at 
1-s intervals followed by a 5-s pause. Most of the energy in the sound 
pulses emitted by this multi-beam sonar is at mid-frequencies, centered 
at 3.5 kHz. The beamwidth is approximately 30[deg] and is directed 
downward. Maximum source output is 204 dB re 1 microPa, 800 watts, 
while nominal source output is 200 dB re 1 microPa, 500 watts. Pulse 
duration will be 4, 2, or 1 ms, and the bandwith of pulses will be 1.0 
kHz, 0.5 kHz, or 0.25 kHz, respectively.
    Along the two selected seismic lines, data will first be acquired 
using multibeam sonar, multichannel seismic, and sonobuoys. A total of 
96 sonobuoys will be available, and the Ewing system allows two 
sonobuoys to be recorded at any time. The sonobuoy profiles will be 
analyzed during the MCS shooting and streamer recovery on each line. 
The preliminary results from the sonobuoy refraction will be used to 
plan the OBH deployment pattern on the subsequent deep refraction 
survey. Twenty OBH's will be deployed for each line.
    Additional information on the airgun arrays, Atlas Hydrosweep, and 
sub-bottom profiler specifications is contained in the application, 
which is available upon request (see ADDRESSES).

Description of Habitat and Marine Mammals Affected by the Activity

    A detailed description of the Northwest Atlantic Ocean and its 
associated marine mammals can be found in a number of documents 
referenced in the LDEO application as well as in the LDEO application 
itself, and is not repeated here. Approximately 32 species of cetaceans 
may be found within the proposed study area near Bermuda. These species 
are the sperm whale (Physeter macrocephalus), pygmy sperm whale (Kogia 
breviceps), dwarf sperm whale (Kogia sima), Cuvier's beaked whale 
(Ziphius cavirostris), True's beaked whale (Mesoplodon mirus), Gervais' 
beaked whale (Mesoplodon europaeus), Sowerby's beaked whale (Mesoplodon 
bidens), 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), Fraser's dolphin (Lagenodelphis hosei), Atlantic white-sided 
dolphin (Lagenorhynchus acutus), Risso's dolphin (Grampus griseus), 
melon-headed whale (Peponocephala electra), pygmy killer whale (Feresa 
attenuata), false killer whale (Pseudorca crassidens), killer whale 
(Orcinus orca), long-finned pilot whale (Globicephala melas), short-

[[Page 58311]]

finned pilot whale (Globicephala macrorhynchus), 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 the blue whale (Balaenoptera musculus). Another three 
species are known to occur just outside of the study area and are not 
likely to be seen within the study area - the northern bottlenose whale 
(Hyperoodon ampullatus (not usually found south of Nova Scotia)), the 
white-beaked dolphin (Lagenorhynchus albirostris (does not normally 
occur south of Cape Cod)), and Fraser's dolphin (Lagenodelphis hosei 
(usually found further south)). Pinnipeds are unlikely to be seen in 
the study area although vagrants of grey (Halichoerus grypus) and 
hooded (Cystophora cristata) seals could occur. Additional information 
on most of these species is contained in Caretta et al. (2001, 2002) 
which is available at: http://www.nmfs.noaa.gov/prot_res/PR2/Stock_Assessment_Program/sars.html.

Potential Effects on Marine Mammals

    The sound pressure fields for the standard and augmented 20-gun 
arrays have been modeled by LDEO, in relation to distance and direction 
from the airguns. As determined by the models, the pressure fields are 
similar for both the 8575 in3 and the 11,000 in3 arrays. Table 1 in the 
application (LDEO Bermuda 2003) shows the maximum distances from both 
20-airgun array configurations where sound levels of [gteqt]190, 180, 
170, and 160 dB re 1 microPa (rms) are predicted to be received:

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Predicted RMS Radii in meters/ft
               20-Airgun Array Volume                ---------------------------------------------------------------------------------------------------
                                                               190 dB                   180 dB                   170 dB                   160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
8575 in\3\..........................................                  275/902                 900/2953                2600/8531              9000/29,529
11,000 in\3\........................................                  300/984                 925/3035                2900/9515              9200/30,185
--------------------------------------------------------------------------------------------------------------------------------------------------------

    An earlier notice of an LDEO application and proposed IHA was 
published in the Federal Register on April 14, 2003 (68 FR 17909). That 
notice described, in detail, the characteristics of the Ewing's 
acoustic sources and, in general, the anticipated effects on marine 
mammals including masking, disturbance, and potential hearing 
impairment and other physical effects. That information is not repeated 
here. In addition, details on acoustic sources from, and possible 
effects of, the sub-bottom profiler, which was not used in the project 
described in the April 14, 2003, notice, were described on July 28, 
2003 (68 FR 44294). The subject LDEO Bermuda application also provides 
information on what is known about the effects on marine mammals of the 
types of seismic operations planned by LDEO.

Estimates of Take by Harassment for the Bermuda Cruise

    As described previously (68 FR 17909, April 14 2003), animals 
subjected to sound levels [gteqt]160 dB may alter their behavior or 
distribution, and therefore might be considered to be taken by Level B 
harassment. However, the 160-dB criterion is based on studies of baleen 
whales. Odontocete hearing at low frequencies is relatively 
insensitive, and dolphins and pilot whales generally appear to be more 
tolerant of strong sounds than are most baleen whales. Delphinidae have 
their best hearing in the higher frequencies and are unlikely to be as 
sensitive as the mysticete whales to the low frequency of the airgun 
array. Therefore, they are less likely to experience Level B harassment 
at 160 dB. A more likely threshold for onset of Level B harassment in 
response to seismic sounds is at about 170 dB.
    The estimates of takes by harassment are based on the number of 
marine mammals that might be exposed to seismic sounds [gteqt]160 dB re 
1 microPa (rms) by operations with the 20-airgun array planned for the 
project. Taken from year-round marine mammal density aerial survey data 
that has been summarized by geographic location and calendar season 
(CETAP 1982), LDEO used densities for the ``Entire Atlantic Stratum'' 
during the autumn period to estimate the numbers of marine mammals that 
are likely to be present in the proposed survey area near Bermuda. 
These densities are probably overestimates of the numbers that are 
likely to be present, because much of the proposed seismic survey area 
is farther from shore, in greater water depths, and in generally much 
less productive waters. Because the CETAP (1982) surveys were conducted 
from an airplane, few beaked whales were seen or identified, and 
densities of beaked whales were estimated to be zero during the autumn 
surveys. More than likely there are small numbers of beaked whales in 
the proposed survey area throughout the year, so LDEO used the mean 
density for the entire year to estimate the densities of beaked whales 
that might be present.
    Except for beaked whales, LDEO used its best estimate of density to 
compute a best estimate of the number of marine mammals that may be 
exposed to seismic sounds[gteqt]160 dB re 1 microPa (rms) (NMFS' 
current criterion for onset of Level B harassment). The best density 
estimates were multiplied by the linear extent of the proposed survey 
(1200 km or 648 n.mi. for each of the 8575 and approximately 11,000 in3 
arrays) and by twice the 160-dB safety radius around the applicable 20-
airgun arrays to estimate the ``best estimate'' of the numbers of 
animals of each species that might be exposed to sound levels 
[gteqt]160 dB re 1 microPa (rms) during the proposed seismic survey 
program.
    Based on this method, Table 3 in the LDEO application gives the 
best estimates, as well as maximum estimates, of densities for each 
species or species group of marine mammal that might be exposed to 
received levels [gteqt]160 dB re 1 microPa (rms), and thus potentially 
taken by Level B harassment during seismic surveys in the proposed 
study area of the Northwest Atlantic Ocean near Bermuda. It is assumed 
that the 20-airgun array would be used for all surveys but that air 
volume would be 8575 in\3\ for half of the survey and approximately 
11,000 in\3\ for half of the survey.
    Delphinidae would account for 94 percent of the overall estimate 
for potential taking by harassment (i.e., 10,292 of 10,910), with 
short-beaked common dolphins (3941) and pilot whales (3345) believed to 
account for about 71 percent of all delphinids in the area of the 
proposed seismic survey, and with smaller numbers of bottlenose 
dolphins (1871), Risso's dolphins (858), and striped dolphins (277) 
accounting for most of the remaining 29 percent. While there is no 
agreement regarding any alternative ``take'' criterion for dolphins 
exposed to airgun pulses, if only those dolphins exposed to [gteqt]170 
dB re 1 microPa (rms) were to be affected sufficiently to be considered 
taken by Level B harassment, then the best estimate for common dolphins 
would be 1191 rather than 3941 during the Bermuda Rise cruise, and for 
pilot whales it would be 1011 instead of

[[Page 58312]]

3345. These are based on the predicted 170-dB radius around the 20-
airgun arrays (2600 m or 8530 ft for the 8575 in\3\ array and 2900 m or 
9514 ft for the approximately 11,000 in\3\ array), and are considered 
to be more realistic estimates of the number of these species that may 
be disturbed. Therefore, the total number of animals likely to be 
harassed is considerably lower than the 10,910 animals that LDEO has 
estimated in Table 3 (LDEO Bermuda 2003).

Conclusions-Effects on Cetaceans

    The proposed airgun array configurations are larger than those used 
in many seismic projects; however, shot intervals are longer than 
during many surveys and so marine mammals will be exposed to fewer 
seismic pulses than during many other similar seismic surveys. The 
pulse interval for the 8575 in\3\ gun array is 20 seconds and is 240 
seconds for the 11,000 in\3\ array.
    Strong avoidance reactions by several species of mysticetes to 
seismic vessels have been observed at ranges up to 6 to 8 km (3.2 to 
4.3 n.mi.) and occasionally as far as 20-30 km (10.8-16.2 n.mi.) from 
the source vessel. Some bowhead whales avoided waters within 30 km 
(16.2 n.mi.) 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 from seismic vessels. 
In fact, there are documented instances of dolphins approaching active 
seismic vessels. However, dolphins as well as some other types of 
odontocetes sometimes show avoidance responses and/or other changes in 
behavior when near operating seismic vessels.
    Taking account of the mitigation measures that are planned, effects 
on cetaceans are generally expected to be limited to avoidance of the 
area around the seismic operation and short-term changes in behavior, 
falling within the MMPA definition of ``Level B harassment.'' In the 
cases of mysticetes, these reactions are expected to involve small 
numbers of individual cetaceans. LDEO's best estimate is that 501 fin 
whales, or 1.1 percent of the estimated North Atlantic fin whale 
population (IWC 2003) will be exposed to sound levels [gteqt]160 dB re 
1 microPa (rms) and potentially affected during the proposed cruise 
near Bermuda. In light of all these factors, these potential takings by 
Level B harassment are expected to have no more than a negligible 
impact on the affected species or stock.
    Larger numbers of odontocetes may be affected by the proposed 
activities, but the population sizes of the main species also are 
larger and the numbers potentially affected are small relative to the 
population sizes. 38 sperm whales or 0.3 percent of the estimated North 
Atlantic sperm whale population would receive seismic sounds [gteqt]160 
dB. Similarly, only 78 beaked whales from the 5 beaked whale species 
may be affected by the proposed activities. This is 2.4 percent of the 
estimated total of all 5 species of beaked whales (3196) that occur 
along the northeast coast of the U.S. Because the CETAP (1982) surveys 
were conducted from an airplane, few beaked whales were seen, or at 
least identified, and densities of beaked whales were estimated to be 
zero during the autumn surveys. However, LDEO believes there are 
probably small numbers of beaked whales in the proposed survey area 
throughout the year, so LDEO used the mean density for the entire year 
to estimate the densities of beaked whales that might be present during 
autumn. Most of the proposed seismic survey area is outside of the area 
for which this 3196 estimate was made, and only a very small part of 
beaked whale habitat in the North Atlantic was included in the 
estimate. Thus the actual estimate is more than likely much larger than 
3196, and the percentage of animals that might receive seismic sounds 
[gteqt]160 dB during the proposed cruise is believed to be less than 1 
percent of the 3196 estimated North Atlantic population of the 5 
species of beaked whales.
    The best estimate of the total number of common dolphins, pilot 
whales, bottlenose dolphins, Risso's dolphins and striped dolphins that 
might be exposed to [gteqt]160 dB re 1 microPa (rms) in the proposed 
survey area near Bermuda are 3941, 3345, 1871, 858 and 277, 
respectively. Of these, about 1191, 1011, 565, 259 and 84, respectively 
might be exposed to [gteqt]170 dB. These figures are <0.1 to <1.1 
percent of the North Atlantic population estimates of these species. 
However, the actual population sizes are much larger than the estimates 
so the percentage of the various populations that might be affected are 
considerably lower than the <0.1 to <1.1 percent mentioned above. The 
values based on the [gteqt]170 dB criterion are believed to be a more 
accurate estimate of the number potentially affected.
    Mitigation measures such as controlled speed, look-outs, non-
pursuit, ramp-ups, and power- and shut-down procedures when within 
defined ranges (See Mitigation) should further reduce short-term 
reactions to disturbance, and minimize any effects on hearing 
sensitivity.

Conclusions-effects on Pinnipeds

    Very few if any pinnipeds are expected to be encountered during the 
proposed seismic survey near Bermuda. However, a few stray hooded and 
grey seals could be encountered. The best estimate of the numbers of 
each of the more common (but unlikely) species that might be taken by 
Level B harassment is no more than two and is most likely zero. It is 
estimated that a maximum of 10 pinnipeds (five for each species) may be 
affected by the proposed seismic surveys. None of the pinniped species 
is considered endangered or vulnerable.
    No pinnipeds regularly occur in the proposed survey area and thus 
none are expected to be encountered. If pinnipeds are encountered, the 
proposed seismic activities would have, at most, a short-term effect on 
their behavior and no long-term impacts on individual seals or their 
populations. Responses of pinnipeds to acoustic disturbance are 
variable, but usually quite limited. Effects are expected to be limited 
to short-term and localized behavioral changes falling within the MMPA 
definition of Level B harassment. Taking these factors into account, 
impacts are expected to be no more than negligible.

Mitigation

    For the proposed seismic operations in the Bermuda Rise area in 
2003, LDEO will use a 20-airgun array. The airguns comprising these 
arrays will be spread out horizontally, so that the energy from the 
arrays will be directed mostly downward.
    The sound pressure fields have been modeled by LDEO in relation to 
distance and direction from the standard and augmented 20-gun array as 
shown in Figures 5 and 6, respectively (LDEO Bermuda 2003). Since the 
sound pressure fields around both configurations of the 20-gun array 
are similar, the marine mammal safety radii for the augmented 20-gun 
array will be used for the duration of the cruise. The radius around 
the augmented 20-gun array where the received level would be 180 dB re 
1 microPa (rms) (the level for onset of Level A harassment applicable 
to cetaceans) is estimated as 925 m (3035 ft). The radius around the 
augmented 20-gun array where the received level would be 190 dB re 1 
microPa (rms), (the level for onset of Level A harassment applicable to

[[Page 58313]]

pinnipeds), is estimated as 300 m (984 ft).
    Vessel-based observers will monitor marine mammals in the vicinity 
of the arrays. LDEO proposes to power-down the seismic source if marine 
mammals are observed within the proposed safety radii. Also, LDEO 
proposes to use a ramp-up procedure when commencing operations using 
the 20-gun array. Ramp-up will begin with the smallest gun in the array 
(80 in\3\ for the standard array and 145 in\3\ for the augmented 
array), and guns will be added in a sequence such that the source level 
of the array will increase at a rate no greater than 6 dB per 5-minute 
period over a total duration of about 25 minutes. Please refer to 
LDEO's application for more detailed information about the mitigation 
measures that are an integral part of the planned activity.

Operational Mitigation

    The directional nature of the airgun array to be used in this 
project is an important mitigating factor, resulting in lower sound 
levels at any given horizontal distance than would be expected at that 
distance if the source were omnidirectional with the stated nominal 
source level. Because the actual seismic source is a distributed sound 
source 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.

Proposed Safety Radii

    Received sound levels have been modeled for the 20-gun array. Based 
on the modeling, estimates of the 190-, 180-, 170-, and 160-dB re 1 
microPa (rms) distances (safety radii) for these arrays have been 
provided previously in this document.
    Airgun operations will be suspended immediately when cetaceans are 
seen within or about to enter the appropriate 180-dB (rms) radius, or 
if pinnipeds are seen within or about to enter the 190-dB (rms) radius. 
These 180- and 190-dB criteria are consistent with guidelines listed 
for cetaceans and pinnipeds by NMFS (2000) and other guidance by NMFS. 
A calibration study was conducted prior to these surveys to determine 
the actual radii corresponding to each sound level. These actual radii 
will be implemented for this study. Until then, or if those 
measurements appear defective, LDEO will use a precautionary 1.5 times 
the modeled 180-dB (cetaceans) and 190-dB (pinnipeds) radii predicted 
by the model as the safety radii.

Mitigation During Operations

    The following mitigation measures, as well as marine mammal 
monitoring, will be adopted during the proposed seismic survey program, 
provided that doing so will not compromise operational safety 
requirements: (1) Speed or course alteration; (2) power-down 
procedures; (3) shut-down procedures; and (4) ramp-up procedures.

Course Alteration

    If a marine mammal is detected outside the safety radius and, based 
on its position and the relative motion, is likely to enter the safety 
radius, the vessel's speed and/or direct course will be changed in a 
manner that also minimizes the effect to the planned science 
objectives. The marine mammal activities and movements relative to the 
seismic vessel will be closely monitored to ensure that the marine 
mammal does not approach within the safety radius. If the mammal 
appears likely to enter the safey radius, further mitigative actions 
will be taken, i.e., either further course alterations or power-down of 
the airguns.

Power-down and Shut-down Procedures

    If a marine mammal is detected outside the safety radius but is 
likely to enter the safety radius, and if the vessel's course and/or 
speed cannot be changed to avoid having the marine mammal enter the 
safety radius, the airguns will be powered-down before the mammal is 
within the safety radius. Likewise, if a mammal is already within the 
safety zone when first detected, the airguns will be powered-down 
immediately. A power-down involves decreasing the number of airguns in 
use such that the radius of the 180-dB zone is decreased to the extent 
that marine mammals are not in the safety radii. A power-down may also 
occur when the vessel is moving from one seismic line to another.
    For the power-down procedure, one airgun (either 80 or 145 in\3\) 
will be operated during the interruption of seismic survey. Airgun 
activity (after both power-down and shut-down procedures) will not 
resume until the marine mammal has cleared the safety radii. The animal 
has cleared the safety radii if it is visually observed to have left 
the safety radii, or if it has not been seen within the radii for 15 
min (small odontocetes and pinnipeds) or 30 min (mysticetes and large 
odontocetes, including sperm, pygmy sperm, dwarf sperm, and beaked 
whales).
    If a cetacean is detected close to the airgun array during a power-
down, modeled safety radii for a single gun will be maintained. If the 
standard 20-gun array is used, the single gun that will be firing is 80 
in\3\, and for the augmented array, it is 145 in\3\. The safety radii 
for the larger 145 in\3\ gun will be used for mitigation purposes. 
Since no calibrations have been done to confirm the modeled safety 
radii for this single gun, conservative (1.5 times the safety radius) 
radii will be used: 48 m or 158 ft (the conservative radius is 72 m or 
236 ft) for cetaceans, and 17 m or 56 ft (the conservative radius is 26 
m or 85 ft) for pinnipeds. If a marine mammal is seen within the 
appropriate safety radius of the array while the guns are powered-down, 
airgun operations will be shut-down. Airgun operations will not resume 
until the marine mammal is outside the safety radius.

Ramp-up Procedure

    A ``ramp-up'' procedure will be followed when the airgun array 
begins operating after a specified-duration period without airgun 
operations. Under normal operational conditions (vessel speed of about 
4 knots or 7.4 km/hr), the Maurice Ewing would travel 900 m (3117 ft) 
in about 8 minutes and a ramp-up would be required after a power-down 
or shut-down period lasting 8 minutes or longer if the Ewing tows a 20-
airgun array. 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. During the ramp-up procedures, the safety zone for the 
full-gun array will be maintained.
    If the airguns are started up at night, two marine mammal observers 
will monitor for marine mammals near the source vessel for 30 minutes 
prior to start up of airgun operations and during the subsequent ramp-
up procedures. 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 was operating during the interruption of 
seismic survey operations.

Monitoring and Reporting

    LDEO proposes to conduct marine mammal monitoring of its 2003 
seismic program near Bermuda in order to satisfy the anticipated 
requirements of the IHA.
    Vessel-based Visual Monitoring
    At least two vessel-based observers dedicated to marine mammal 
observations will be stationed aboard LDEO's seismic survey vessel for 
the seismic survey near Bermuda. At least one experienced marine mammal 
observer will be on duty aboard the seismic vessel, and observers will 
be

[[Page 58314]]

appointed by LDEO with NMFS concurrence. Observers will be on duty in 
shifts of duration no longer than 4 hours. Use of two simultaneous 
observers will increase the proportion of the marine mammals present 
near the source vessel that are detected.
    It is proposed that one or two marine mammal observers aboard the 
seismic vessel will search for and observe marine mammals whenever 
seismic operations are in progress during daylight hours, and if 
feasible, observations will also be made during periods without seismic 
activity. Two observers will monitor for marine mammals near the 
seismic source vessel for at least 30 minutes prior to and during all 
daylight airgun operations including ramp-ups, after an extended shut-
down, and during any nighttime startups of the airguns. Airgun 
operations will be suspended when marine mammals are observed within, 
or about to enter, designated safety radii, where there is a 
possibility of Level A harassment. Observers will not be on duty during 
ongoing seismic operations at night; bridge personnel will watch for 
marine mammals during this period and will call for the airguns to be 
powered-down if marine mammals are observed in or about to enter the 
safety radii. At least one marine mammal observer will be on 
``standby'' at night, in case bridge personnel see a marine mammal. An 
image-intensifier night-vision device (NVD) will be available for use 
at night. 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. The 30-minute observation period is only 
required prior to commencing seismic operations following a shut-down 
of the 20-gun array for more than 1 hour. After 30 minutes of 
observation, the ramp-up procedure will be followed.
    The R/V Maurice Ewing is a suitable platform for marine mammal 
observations. Observers will watch for marine mammals from the highest 
practical vantagepoint on the vessel, which is either the bridge or the 
flying bridge. The observer's eye level will be approximately 11 m (36 
ft) above sea level when stationed on the bridge, allowing for good 
visibility within a 210[deg] arc for each observer. If observers are 
stationed on the flying bridge, the eye level will be 14.4 m (47.2 ft) 
above sea level. The proposed monitoring plan is summarized later in 
this document. The observer(s) will systematically scan the area around 
the vessel with 7 X 50 Fujinon reticle binoculars or with the naked eye 
during the daytime. At night, night vision equipment 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. If a marine mammal is seen well outside the safety radius, 
the vessel may be maneuvered to avoid having the mammal come within the 
safety radius (see Mitigation). When mammals are detected within or 
about to enter the designated safety radii, the airguns will be 
powered-down immediately. The observer(s) will continue to maintain 
watch to determine when the animal is outside the safety radius. Airgun 
operations will not resume until the animal is outside the safety 
radius or until the specified intervals (15 or 30 min) have passed 
without a re-sighting.

Reporting

    The vessel-based monitoring will provide data required to estimate 
the numbers of marine mammals exposed to various received sound levels, 
to document any apparent disturbance reactions, and thus to estimate 
the numbers of mammals potentially taken by Level B harassment. It will 
also provide the information needed in order to shut down the airguns 
at times when mammals are present in or near the safety zone. When a 
mammal 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 seismic vessel (e.g., none, 
avoidance, approach, paralleling, etc.), and behavioral pace; and (2) 
time, location, heading, speed, activity of the vessel (shooting or 
not), 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 and airgun shutdowns will be recorded in a 
standardized format. Data will be entered into a custom database using 
a laptop computer when observers are off-duty. The accuracy of the data 
entry will be verified by computerized validity data checks as the data 
are entered and by subsequent manual checking of the database. These 
procedures will allow initial summaries of data to be prepared during 
and shortly after the field program, and will facilitate transfer of 
the data to statistical, graphical or other programs for further 
processing and archiving.
    Results from the vessel-based observations will provide (1) the 
basis for real-time mitigation (airgun power-down); (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) information to compare the distance and 
distribution of marine mammals relative to the source vessel at times 
with and without seismic activity; and (5) data on the behavior and 
movement patterns of marine mammals seen at times with and without 
seismic activity.
    A report will be submitted to NMFS within 90 days after the end of 
the seismic program in the Bermuda Rise area. The end of the seismic 
program is predicted to occur on or about December 9, 2003. The report 
will describe the operations that were conducted and the marine mammals 
that were detected near the operations, and will be submitted to NMFS, 
providing full documentation of methods, results, and interpretation 
pertaining to all monitoring tasks. The 90-day report will summarize 
the dates and locations of seismic operations, sound measurement data, 
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. The draft report will be considered the final report unless 
comments and suggestions are provided by NMFS within 60 days of its 
receipt of the draft report.

Endangered Species Act (ESA)

    Under section 7 of the ESA, NMFS has begun consultation on the 
proposed issuance of an IHA under section 101(a)(5)(D) of the MMPA for 
this activity. Consultation will be concluded prior to the issuance of 
an IHA.

National Environmental Policy Act (NEPA)

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

Preliminary Conclusions

    NMFS has preliminarily determined that the impact of conducting a 
seismic survey program in the Bermuda Rise

[[Page 58315]]

portion of the Northwest Atlantic Ocean 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.
    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 will not take place in or near subsistence 
hunting areas.
    Proposed Authorization
    NMFS proposes to issue an IHA to LDEO for conducting a seismic 
survey program in the Bermuda Rise portion of the Northwest Atlantic 
Ocean, provided the proposed mitigation, monitoring, and reporting 
requirements are incorporated. NMFS has preliminarily determined that 
the proposed activity would result in the harassment of small numbers 
of marine mammals; would have no more than a negligible impact on the 
affected marine mammal stocks; and would not have an unmitigable 
adverse impact on the availability of stocks for subsistence uses.

Information Solicited

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

    Dated: October 3, 2003.
Laurie K. Allen,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 03-25639 Filed 10-08-03; 8:45 am]
BILLING CODE 3510-22-S