[Federal Register Volume 68, Number 177 (Friday, September 12, 2003)]
[Notices]
[Pages 53714-53720]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-23309]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 052803A]


Taking Marine Mammals Incidental to Specified Activities; 
Oceanographic Surveys at the Storegga Slide, Norwegian Sea

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

ACTION: Notice of issuance of an incidental harassment authorization.

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SUMMARY: In accordance with provisions of the Marine Mammal Protection 
Act (MMPA) as amended, notification is hereby given that an Incidental 
Harassment Authorization (IHA) to take small numbers of marine mammals, 
by harassment, incidental to conducting oceanographic surveys at the 
Storegga Slide off the west coast of Norway in the Norwegian Sea has 
been issued to Lamont-Doherty Earth Observatory (LDEO).

DATES: Effective from August 28, 2003, through August 27, 2004.

ADDRESSES: The application, a list of references used in this document, 
and/or the IHA are available by writing 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.

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

[[Page 53715]]

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 April 21, 2003, NMFS received an application from LDEO for the 
taking, by harassment, of several species of marine mammals incidental 
to conducting a seismic survey program within the Storegga slide area 
off the west coast of Norway, in the Norwegian Sea, between 8oW and 7oE 
and between 62 and 68oN, during late August and September 2003. The 
Storegga slide was produced by colossal slope failures on the Norwegian 
continental margin in the late Quarternary period. The purpose of this 
survey is to determine whether submarine landslides can release methane 
from hydrate into the oceans and/or atmosphere. More specifically, the 
survey of the Storegga slide seeks to discover: (1) How much hydrate 
and free gas is present in the Storegga region and how it is 
distributed, (2) if methane escaped from the slide, and if so, how 
much, when and by what mechanisms, and (3) if hydrate dissociation 
promotes and/or localizes submarine landslides. A coordinated seismic 
and coring study of the Storegga slide is proposed to obtain 
information on these subjects (the coring portion of the project will 
be completed in 2004). This study will help explain whether methane in 
gas hydrate reservoirs is mobile and can affect the earth's climate.

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 airguns as an energy source, plus a 6-km (3.2-nm) 
towed streamer containing hydrophones to receive the returning acoustic 
signals.
    All planned geophysical data acquisition activities will be 
conducted by LDEO scientists, with the participation of scientists from 
the University of Wyoming. Water depths within the Storegga slide 
survey area will range from approximately 100 to 5,000 m (330 to 16,405 
ft). The Maurice Ewing will initially deploy a 2-General Injector (GI) 
gun array for several survey lines, and then a 6-airgun array will be 
employed for several survey lines. Whichever array produces better data 
will be used for the rest of the cruise. The project will consist of 
3,109 km (1,678 n.mi) of survey lines, of which approximately 2,596 km 
(1,402 n.mi) will be conducted in water depths greater than 1,000 m 
(3,280 ft), 504 km (272 n.mi) will be surveyed in depths 100-1000 m 
(330-3,280 ft), and 9 km (4.9 n.mi) will be surveyed in water less than 
100 m (330 ft) deep. 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. The energy to the airgun array is 
compressed air supplied by compressors on board the source vessel. 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 August 28, 2003, and 
continue until September 25, 2003, for a total of 29 days of seismic 
surveying.
    The R/V Maurice Ewing will be used as the source vessel. It will 
tow the airgun array (either the 2-GI gun or 6-gun array) and a 
streamer containing hydrophones along predetermined lines. The vessel 
will travel at 4-5 knots (7.4-9.3 km/hr), and 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). The 6-gun array 
will include six 2000 psi 1500C Bolt airguns ranging in chamber volume 
from 80 to 500 in3, with a total volume of 1,350 in3. These airguns 
will be spaced in an approximate rectangle with dimensions 12 m (39.4 
ft)(across track) by 10 m (32.8 ft)(along track). The two 105 in3 GI 
guns will be towed 7.8 m (25.6 ft) apart side by side and 37 m (121.4 
ft) behind the vessel, with a total volume of 210 in\3\.
    The dominant frequency components for both airgun arrays is 0 - 188 
Hz. The 2-airgun array will have a peak sound source level of 237 dB re 
1 microPa or 243 dB peak-to-peak (P-P). The 6-airgun array will have a 
peak sound source level of 243 dB re 1 microPa or 250 dB P-P. These are 
the nominal source levels for the sound directed downward, and 
represent the theoretical source level close to a single point source 
emitting the same sound as that emitted by the array of 2 or 6 sources. 
Because the actual source is a distributed sound source (2 or 6 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 downward directional nature of the sound 
from these airgun arrays, 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 multi-beam 
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 mode is when water depth is <400 m (1312.3 ft). The source 
output is 210 dB re 1 Pa-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 beamwidth. The

[[Page 53716]]

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 (1640.4 ft) and 10 millisec 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. Sounds from the 
sub-bottom profiler are very short pulses, occurring for 1, 2 or 4 msec 
once every second. 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.
    Sound levels have not been measured for the sub-bottom profiler 
used by the Maurice Ewing, but Burgess and Lawson (2000) measured the 
sounds propagating more or less horizontally from a similar unit with 
similar source output (205 dB re 1 microPa-m). The 160 and 180 dB re 1 
microPa (rms) radii, in the horizontal direction, were estimated to be 
near 20 m (66 ft) and 8 m (26 ft), respectively, from the source, as 
measured in 13 m (43 ft) water depth. The corresponding distances for 
an animal in the beam below the transducer would be greater, on the 
order of 180 m (591 ft) and 18 m (59 ft), assuming spherical spreading.
    The sub-bottom profiler on the Maurice Ewing has a maximum source 
level of 204 dB re 1 microPa-m. Thus the received level would be 
expected to decrease to 160 and 180 dB at about 160 m (525 ft) and 16 m 
(52 ft) below the transducer, respectively (assuming spherical 
spreading). Corresponding distances in the horizontal plane would be 
lower, given the directionality of this source (30o beamwidth) and the 
measurements of Burgess and Lawson (2000). 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).

Comments and Responses

    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. In addition, another notice of 
receipt of an LDEO application and proposed IHA was published in the 
Federal Register on July 28, 2003 (68 FR 44291). That notice described 
in detail the proposed activity and the marine mammal species that may 
be affected by it. That information is not repeated here. During the 
30-day public comment period, comments were received from the Marine 
Mammal Commission (Commission).

Monitoring Concerns

    Comment 1: The Commission believes that NMFS preliminary 
determinations are reasonable, provided NMFS is satisfied that the 
proposed mitigation and monitoring activities are adequate to detect 
marine mammals in the vicinity of the proposed operations and ensure 
that marine mammals are not being taken in unanticipated ways or 
numbers. In this regard, NMFS Federal Register notice and the 
application state that [v]essel-based observers will monitor marine 
mammals near the seismic source vessel during all daylight airgun 
operations and during any nighttime startups of the airguns;'' and that 
bridge personnel will watch for marine mammals during nighttime 
activities but that ``[o]bservers will not be on duty during ongoing 
seismic operations at night. The Federal Register notice states that 
image-intensifier night-vision devices (NFDs) will be available for use 
at night, although past experience has shown that NFDs are of limited 
value for this purpose.'' Thus it is unclear that, for nighttime 
activities, the monitoring effort will be sufficient to determine that 
no marine mammals are within the safety zones at start-up or will be an 
effective means of detecting when marine mammals enter the safety zones 
during operations such that activities are suspended before received 
levels of 180 and 190 dB (rms) are reached.
    Response: As part of the IHA, NMFS is requiring that if the airguns 
are started up at night, two marine mammal observers will monitor for 
marine mammals within the safety radii for 30 minutes prior to start up 
using night vision devices as described later (see Monitoring and 
Reporting). Airgun operations will be suspended when marine mammals are 
observed within or about to enter designated safety zones, and 
operations will not resume until the animal is outside the safety 
radius. Once the safety zone is clear of marine mammals, the observer 
will advise that seismic surveys can re-commence. The ``ramp-up'' 
procedure will then be followed. Because the sizes of the two airgun 
arrays to be used are small, the safety zones are relatively small, and 
there are no ``power-down'' procedures, ramp-up may not commence unless 
the entire safety radii is visible for 30 minutes prior to ramp-up in 
either daylight or nighttime. The combination of the two conditions 
ensures, to the greatest extent practicable, that no mammals will be 
within the appropriate safety zones whenever the airguns are turned on, 
either in daylight or nighttime.
    However, it is noted that at times, pinnipeds and even some small 
cetaceans will approach a vessel during transmissions (the vessel 
itself moving forward at about 3-5 knots) from the side of the vessel 
or the stern, meaning that the animal is voluntarily approaching a 
noise source that is increasing in strength as the animal gets closer. 
Experience indicates that pinnipeds will come from great distances to 
scrutinize seismic-reflection operations. Seals have been observed 
swimming within airgun bubbles only 10 m (33 ft) away from active 
arrays. Also, Canadian scientists, who were using a high-frequency 
seismic system that produced sound frequencies closer to pinniped 
hearing than those used by the Ewing, describe how seals frequently 
approached close to the seismic source, presumably out of curiosity. 
Therefore, because at least pinnipeds indicated no adverse behavioral 
reaction to seismic noise, NMFS has concluded that the above-mentioned 
mitigation requirement is reasonable because the bridge-watch will be 
concentrating on marine mammals approaching the vessel from the bow. 
Also, the night-vision ability of

[[Page 53717]]

the trained bridge-watch staff will be better than observers elsewhere 
on the vessel where normal ship-board lighting is more likely. Finally, 
an observer is still required to be on standby, meaning he or she will 
be in the vicinity of the bridge and is not precluded from conducting 
observations during night-time.
    Comment 2: The Commission notes that there is no discussion on why 
nighttime operations are considered necessary.
    Response: The daily cost to the Federal government to operate the 
Ewing is approximately $33,000-$35,000/day (Ljunngren, pers. comm. May 
28, 2003), or approximately $1,050,000 for this 30-day research cruise. 
If the Ewing is prohibited from operating during nighttime, the 30-day 
trip would require an additional 3-5 days, or up to $105,000-175,000 
more, depending upon average daylight at the time of the work.
    Therefore, because NMFS has determined that the safety zone must be 
visible during ramp-up, and because once the Ewing is underway and 
ramp-up completed, mammals will have sufficient notice of a vessel 
approaching (at least one hour) to avoid the approaching array if the 
sounds are annoying, NMFS determined that it is neither practical nor 
necessary to limit seismic operations to daylight hours since marine 
mammals are unlikely to be injured.
    Comment 3: The Commission notes that it is unclear whether vessel-
based passive acoustic monitoring will be conducted as an adjunct to 
visual monitoring during daytime and particularly during nighttime 
operations to detect, locate, and identify marine mammals, and, if not, 
why not.
    Response: The passive acoustical monitoring equipment that was used 
onboard the Ewing during the 2003 Gulf of Mexico (GOM) Sperm Whale 
Seismic Study (SWSS), is not the property of LDEO or the Ewing, and 
therefore is not available for the Norwegian Sea cruise. LDEO is 
presently evaluating the scientific results of the passive sonar from 
the SWSS trip to determine whether it is practical to incorporate it 
into future seismic research cruises. NMFS expects a report on this 
analysis shortly.
    Comment 4: The Commission asks whether conducting monitoring for at 
least 30 minutes prior to the planned start of airgun operations during 
the day and at night is sufficient, particularly for detecting the 
presence of species that make long dives.
    Response: NMFS believes it is unnecessary to lengthen this period 
considering that the ramp-up period will increase SPLs at a rate no 
greater than 6 dB per 5-minutes for a total ramp-up duration of 
approximately 14 min for the 6 gun array. Also, while some whale 
species may dive for up to 45 minutes, it is unlikely that the ship's 
bridge watch would miss a large whale surfacing from its previous dive 
if it is within a mile or two of the vessel.
    Comment 5: The Commission notes that there are several species of 
beaked whales in the Norwegian Sea, and states that ``although the link 
between the Gulf of California strandings and the seismic (plus multi-
beam sonar) survey is inconclusive, this....suggests a need for caution 
in conducting seismic surveys in areas occupied by beaked whales.'' The 
Service's Federal Register notice, however, makes no reference to or 
requirement for any additional caution with respect to beaked whales.
    Response: While NMFS shares the Commission's concern regarding the 
possible relationship between low-frequency seismic survey 
transmissions and the beaked whale strandings in the Gulf of 
California, NMFS believes that additional factors probably also 
influence whether beaked whales will be affected in ways other than 
possibly vacating the immediate vicinity of the noise similar to other 
marine mammal species. For example, beaked whales in the Gulf of Mexico 
have been exposed to seismic noise for several decades but mass 
stranding events similar to the 2000 event in the Bahamas do not appear 
in the stranding record. However, NMFS welcomes recommendations 
regarding additional practical mitigation measures to protect beaked 
whales from anthropogenic sounds. A notice of receipt of an LDEO 
application and proposed IHA was published in the Federal Register on 
July 28, 2003 (68 FR 44291).

Mitigation

    For the seismic operations in the Storegga slide area, LDEO will 
use 2 GI guns with a total volume of 210 in3 and/or a 6-gun array with 
a total volume of 1350 in3. The airguns comprising these arrays will be 
spread out horizontally, so that the energy from the arrays will be 
directed mostly downward. The directional nature of the airgun arrays 
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 (2 or 6 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.

Safety Radii

    Modeled results for the 2- and 6-gun arrays indicate received 
levels to the 180-dB re 1 microPa (rms) isopleth (the level for the 
potential for Level A harassment applicable to cetaceans) were 
estimated as 50 and 220 m (164 and 722 ft), respectively. The radii 
around the 2- and 6-gun arrays where the received level would be 190 dB 
re 1 microPa (rms), (the level for the potential for Level A harassment 
applicable to pinnipeds), were estimated as 15 and 50 m (49 and 164 
ft), respectively. A calibration study was conducted prior this survey 
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 180-dB (cetaceans) and 190-dB (pinnipeds) radii predicted by 
the model as the safety radii. Under those circumstances, the safety 
radii for cetaceans are 75 and 330 m (246 and 1,083 ft), respectively, 
for the 2-GI gun and 6-gun arrays, and the proposed safety radii for 
pinnipeds are 23 and 75 m (75 and 246 ft), respectively.

Shutdown Procedures

    Vessel-based observers will monitor marine mammals near the seismic 
vessel during daylight and for at least 30 minutes prior to start up 
during darkness throughout the program. Airgun operations will be 
suspended immediately when marine mammals are observed within, or about 
to enter, designated safety zones. The shutdown procedure should be 
accomplished within several seconds or a single seismic ping of the 
determination that a marine mammal is within or about to enter the 
safety zone.

Power-down Procedures

    Vessel-based observers will monitor marine mammals near the seismic 
vessel during daylight and for 30 minutes prior to start up during 
darkness throughout the program. The same procedures for shut-down will 
be followed in the case that marine mammals are seen within, or about 
to enter, designated safety zones.

Ramp-up Procedure

    A standard ``ramp-up'' (soft start) procedure will be followed when 
the airgun arrays begin operating after a period without any airgun 
operations as specified in this paragraph. From shut-down, ramp-up will 
begin with the

[[Page 53718]]

smallest gun in the 6-gun array (80 in3), and guns 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 14 min. Under normal operational conditions (vessel speed 
4-5 knots), a ramp-up will be required after a ``no shooting'' period 
lasting 2 minutes or longer. At 4 knots, the source vessel would travel 
247 m (810 ft) during a 2-minute period. If the towing speed is reduced 
to 3 knots or less, as sometimes required when maneuvering in shallow 
water, ramp-up will be required after a ``no shooting'' period lasting 
3 minutes or longer. At towing speeds not exceeding 3 knots, the source 
vessel would travel no more than 277 m (909 ft) in 3 minutes. These 
guidelines would require modification if the normal shot interval were 
more than 2 or 3 min, but that is not expected to occur during the 
Storegga slide cruise. During the ramp-up procedures, the safety zone 
for the full gun array will be maintained. Ramp-up will not occur for 
the 2-GI gun array, since the total air discharge volume for this array 
is small (210 in3).

Course Alteration

    If a marine mammal is detected outside the safety radius and, based 
on its position and relative motion, is likely to enter the safety 
radius, alternative ship tracks will be plotted against anticipated 
mammal locations. The vessel's direct course and/or speed will be 
changed in a manner that also minimizes the effect to the planned 
science objectives. The marine mammal activities and movements relative 
to the seismic vessel will be closely monitored to ensure that the 
marine mammal does not approach within the safety radius. If the mammal 
appears likely to enter the safety radius, further mitigative actions 
will be taken, i.e., either further course alterations or shutdown of 
the airguns. The Ewing is required to adopt this mitigation measure 
during the Norwegian Sea seismic survey program provided that doing so 
will not compromise operational safety requirements.

Marine Mammal Monitoring

    LDEO will conduct marine mammal monitoring during its seismic 
program in the Norwegian Sea in order to verify that the taking of 
marine mammals, by harassment, incidental to conducting the seismic 
survey will have a negligible impact on marine mammal stocks and to 
ensure that these harassment takings are at the lowest level 
practicable. Up to three vessel-based observers will be stationed on 
the R/V Maurice Ewing during seismic operations in the Storegga slide 
area. Vessel-based observers will monitor for marine mammals near the 
seismic source vessel for at least 30 minutes prior to and during all 
daylight ramp-up and airgun operations, and for at least 30 minutes 
before and during any nighttime startups of the airguns. At least one 
experienced marine mammal observer will be on duty aboard the seismic 
vessel, as well as a fisheries expert (as likely required by the 
Norwegian Petroleum Directorate (2003)) and possibly one qualified 
contract biologist. Observers (appointed by LDEO) will complete a 
training/refresher course on marine mammal monitoring procedures, given 
by a contract employee experienced in vessel-based seismic monitoring 
projects. The Ewing is a suitable platform for marine mammal 
observations. The observer's eye level will be approximately 11 m (36 
ft) above sea level when stationed on the bridge (the highest practical 
vantage point on the vessel), allowing for good visibility within a 
210[deg] arc for each observer. Airgun operations will be suspended 
when marine mammals are observed within, or about to enter, designated 
safety zones. 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. Once the safety zone is clear of marine mammals, the observer 
will advise that seismic surveys can re-commence. The ``ramp-up'' 
procedure will then be followed.
    Observers will be on duty in shifts of duration no longer than 4 
hours. Use of two simultaneous observers whenever possible will 
decrease the potential that marine mammals near the source vessel will 
be missed. Bridge personnel will also assist in detecting marine 
mammals and implementing mitigation requirements, and before the start 
of the seismic survey will be given proper instruction for observing 
and reporting marine mammals and sea turtles.
    Observers will not normally be on duty during ongoing seismic 
operations at night; bridge personnel will watch for marine mammals 
during this period and will immediately call for the airguns to be 
shut-down or powered-down if marine mammals are observed in or about to 
enter the safety radii. A marine mammal observer will be on ``standby'' 
at night, in case bridge personnel see a marine mammal. 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 
using night-vision devices. An image-intensifier night-vision device 
(NVD) will be available for use at night, although NMFS notes that past 
experience has shown that NVDs are of limited value for this purpose. 
If the complete safety radii are not visible for at least 30 minutes 
prior to ramp-up in either daylight or nighttime, ramp-up may not 
commence unless the seismic source has maintained an SPL of at least 
180 dB during the interruption of seismic survey operations.
    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 (Bushnell Lytespeed 800 laser rangefinder with 
4 optics or equivalent) will be available to assist with distance 
estimation.
    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 zones. 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.

Reporting

    When a marine 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,

[[Page 53719]]

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.
    A draft report will be submitted to NMFS within 90 days after the 
end of the seismic program in the Storegga slide area. The end of the 
Storegga slide program is predicted to occur on or about September 25, 
2003. The report will cover the seismic surveys in the Storegga slide 
area and will be submitted to NMFS, providing full documentation of 
methods, results, and interpretation pertaining to all monitoring 
tasks. The 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.

Estimates of Take by Harassment for the Norwegian Sea Cruise

    As described previously (see 68 FR 17909, April 14, 2003) and in 
the LDEO application, 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.
    Based on summer marine mammal density survey data collected by 
Sigurjonsson and Gunnlaugsson (1989), 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), except for 
bottlenose whales. Northern bottlenose whales are migratory and most 
leave the proposed seismic survey area before the end of June 
(Benjaminsen 1972; Sigurjonsson and Gunnlaugsson 1990). Therefore, only 
a few, if any, bottlenose whales may be seen during the seismic survey 
in the study area during late August to September. For bottlenose 
whales, LDEO used 0.10x the observed average or maximum density to 
calculate the numbers that might be exposed to seismic sounds, but even 
this reduced number is likely a high estimate. For all other species, 
the average densities were then multiplied by the proposed survey 
effort (3109 km or 1678 n.mi) and twice the 160-dB safety radius around 
the 6-gun array to estimate the ``best estimate'' of the numbers of 
animals that might be exposed to sound levels [gteqt]160 dB re 1 
microPa (rms) during the proposed seismic survey program.
    The estimates of takes by harassment are based on the number of 
marine mammals that might be found within the 160 dB isopleth radius 
and potentially disturbed by operations with the 6-airgun array planned 
for the project. If the 2-GI gun array is used for all or part of the 
survey, the numbers of marine mammals that might be affected by the 
proposed seismic survey would be lower than the estimates described 
below. The 160-dB radius for the 2-GI gun array is 520 m (1706 ft) or 
19 percent of that of the 6-gun array. If only the 2-GI gun array is 
used, the numbers of animals that would encounter airgun sounds 
[gteqt]160 dB re 1 (rms) would be about one-fifth of the number if only 
the 6-gun array were used.
    Based on this method, Table 3 in LDEO (2003) gives the best 
estimates of densities for each species or species group of marine 
mammal that might be exposed to received levels 160 dB re 1 
microPa (rms), and thus potentially taken by Level B harassment, during 
seismic surveys in the proposed study area of the Norwegian Sea. Of 
these, 86 animals would be endangered species, primarily fin (42), 
humpback (22), and sperm whales (18). Delphinidae would account for 75 
percent of the overall estimate for potential taking by harassment, 
with white-beaked dolphins (298) believed to account for about 90 
percent of all delphinids in the area of the proposed seismic survey, 
and with killer whales (137) and long-finned pilot whales (302) 
accounting for most of the remaining 10 percent.

Conclusions

Effects on Cetaceans

    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 nm) and occasionally as far as 20-30 km (10.8-16.2 nm) from the 
source vessel. Some bowhead whales avoided waters within 30 km (16.2 
nm) of the seismic operation. However, reactions at such long distances 
appear to be atypical of other species of mysticetes, and even for 
bowheads may only apply during migration.
    Odontocete reactions to seismic pulses, or at least those of 
dolphins, are expected to extend to lesser distances than are those of 
mysticetes. Odontocete low-frequency hearing is less sensitive than 
that of mysticetes, and dolphins are often seen 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 because few mysticetes occur in the 
area where seismic surveys are proposed. LDEO's best estimate is that 
42 fin whales, or 0.5 percent of the estimated fin whale population in 
and adjacent to the study area, will be exposed to sound levels 
160 dB re 1 microPa (rms) and potentially affected. 
Similarly, 22 humpback whales, or 0.8 percent, and 18 sperm whales, or 
0.2 percent of their populations that occur in and adjacent to the 
proposed survey area, would receive seismic sounds 160 dB. 
Numbers and impact would be even smaller if the 2-GI gun array is used 
for a substantial fraction of the survey project.
    Larger absolute numbers of odontocetes may be affected by the 
proposed activities, but the population sizes of the main species are 
large and the numbers potentially affected are small relative to the 
population sizes. The best estimate of the total number of odontocetes 
that might be exposed to [gteqt]160 dB re 1 microPa (rms) in the 
proposed survey area in the Norwegian Sea is 878. Of these, 770 are 
Delphinidae, and of these about 200 might be exposed to [gteqt]170 dB. 
These figures are <0.1 percent of the populations of these combined 
species that occur in the Northeast Atlantic. These potential takings 
of small numbers of marine mammals by short-term Level B harassment 
will have

[[Page 53720]]

a negligible impact on the affected species or stocks of cetaceans.

Effects on Pinnipeds

    Very few if any pinnipeds are expected to be encountered during the 
proposed seismic survey in the Norwegian Sea. A maximum of 70 pinnipeds 
in the Storegga slide area may be affected by the proposed seismic 
surveys. 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. These effects would have no more than a negligible impact 
on the affected species or stocks of pinnipeds.

Determinations

    Based on the information contained in the LDEO application, the NSF 
EA, the July 28, 2003, proposed authorization notice (68 FR 44291) and 
this document, NMFS has determined that conducting a seismic survey by 
the Ewing at the Storegga Slide in the Norwegian Sea in the fall of 
2003 by LDEO would result in the harassment of small numbers of marine 
mammals; would have no more than a negligible impact on the affected 
marine mammal species or stocks; and would not have an unmitigable 
adverse impact on the availability of stocks for subsistence uses. This 
activity will result, at worst, in a temporary modification in behavior 
by affected species of marine mammals. While behavioral modifications 
may be made by these species as a result of seismic survey activities, 
this behavioral change is expected to result n no more than a 
negligible impact on the affected species. Also, while the number of 
actual 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 and required under the IHA. For these 
reasons therefore, NMFS has determined that the requirements of section 
101(a)(5)(D) of the MMPA have been met and the authorization can be 
issued.

Endangered Species Act

    NMFS has concluded consultation under section 7 of the ESA on NMFS' 
issuance of an IHA to take small numbers of marine mammals, by 
harassment, incidental to conducting an oceanographic seismic survey in 
the Norwegian Sea by LDEO. The consultation concluded with a biological 
opinion that this action is not likely to jeopardize the continued 
existence of marine species listed as threatened or endangered under 
the ESA. No critical habitat has been designated for these species in 
the equatorial Pacific Ocean; therefore, none will be affected. A 
conservation recommendation was made to ensure that the safety zone is 
clear of sea turtles prior to ramp up. This recommendation has been 
implemented through the IHA to LDEO. A copy of the Biological Opinion 
is available upon request (see ADDRESSES).

National Environmental Policy Act (NEPA)

    On May 1, 2003, the NSF made a determination, based on information 
contained within its EA that implementation of the subject action is 
not a major Federal action having significant effects on the 
environment within the meaning of Executive Order 12114. NSF determined 
therefore, that an environmental impact statement would not be 
prepared. On July 28, 2003 (68 FR 44291), NMFS noted that the NSF had 
prepared an EA for the Norwegian Sea survey and that this EA was 
available upon request. In accordance with NOAA Administrative Order 
216-6 (Environmental Review Procedures for Implementing the National 
Environmental Policy Act, May 20, 1999), NMFS has reviewed the 
information contained in NSF's EA and determined that the NSF EA 
accurately and completely describes the proposed action alternative, 
reasonable additional alternatives, and the potential impacts on marine 
mammals, endangered species, and other marine life that could be 
impacted by the preferred alternative and the other alternatives. As a 
result, NMFS has determined that it is not necessary to issue either a 
new EA, supplemental EA or an environmental impact statement for the 
issuance of an IHA to LDEO for this activity. Therefore, based on this 
review and analysis, NMFS is adopting the NSF EA under 40 CFR 1506.3. A 
copy of the NSF EA for this activity is available upon request (see 
ADDRESSES).

Authorization

    NMFS has issued an IHA to take small numbers of marine mammals, by 
harassment, incidental to conducting a seismic survey by the Ewing at 
the Storegga Slide in the Norwegian Sea to LDEO for a 1-year period, 
provided the mitigation, monitoring, and reporting requirements 
described in this document and the IHA are undertaken.

    Dated: August 28, 2003.
Laurie K. Allen,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 03-23309 Filed 9-11-03; 8:45 am]
BILLING CODE 3510-22-S