Small Takes of Marine Mammals Incidental to Open-water Seismic Operations in the Chukchi Sea, 43112-43132 [06-6584]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 71, Number 146 (Monday, July 31, 2006)]
[Notices]
[Pages 43112-43132]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-6584]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 042606H]


Small Takes of Marine Mammals Incidental to Open-water Seismic 
Operations in the Chukchi Sea

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

ACTION: Notice; issuance of Incidental Harassment Authorization.

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SUMMARY: Notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to Conoco Phillips Alaska, 
Inc, (Conoco) to take small numbers of marine mammals, by harassment, 
incidental to conducting open-water seismic data aquisition in the 
Chukchi Sea during the summer and fall of 2006.

DATES: The authorization is effective July 7, 2006, through December 
31, 2006.

ADDRESSES: Copies of the IHA and the application are available by 
writing to Michael Payne, Chief, Permits, Conservation, and Education 
Division, Office of Protected Resources, National Marine Fisheries 
Service, 1315 East-West Highway, Silver Spring, MD 20910-3225, or by 
telephoning the contact listed here. A copy of the application 
containing a list of references used in this document may be obtained 
by writing to this address, by telephoning the contact listed here (FOR 
FURTHER INFORMATION CONTACT) or online at: https://www.nmfs.noaa.gov/pr/
permits/incidental.htm. Documents cited in this notice may be viewed, 
by appointment, during regular business hours, at the aforementioned 
address.

FOR FURTHER INFORMATION CONTACT: Jolie Harrison, Office of Protected 
Resources, NMFS, (301) 713-2289, ext 166.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region if certain findings are 
made and either regulations are issued or, if the taking is limited to 
harassment, a notice of a proposed authorization is provided to the 
public for review.
    Authorization shall be granted if NMFS finds that the taking will 
have a negligible impact on the species or stock(s), will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses, and that the permissible methods of 
taking and requirements pertaining to the mitigation, monitoring and 
reporting of such takings are set forth. NMFS has defined ``negligible 
impact'' in 50 CFR 216.103 as ''...an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Except with respect to certain activities not pertinent here, the MMPA 
defines ``harassment'' as:
    any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild [Level A harassment]; or (ii) has the potential to disturb a 
marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, breeding, feeding, or sheltering 
[Level B harassment].
    Section 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
marine mammals. Within 45 days of the close of the comment period, NMFS 
must either issue or deny issuance of the authorization.

Summary of Request

    On February 2, 2006, NMFS received an application from Conoco for 
the taking, by harassment, of several species of marine mammals 
incidental to conducting open-water seismic data acquisition in the 
Chukchi Sea from July through November, 2006. Seismic surveys such as 
the one described here provide accurate data on the location, extent, 
and properties of hydrocarbon

[[Page 43113]]

resources as well as information on shallow geologic hazards and 
seafloor geotechnical properties to explore, develop, produce, and 
transport hydrocarbons safely, economically, and in an environmentally 
safe manner. This information is utilized by both the oil and gas 
industry and the Minerals Management Service (MMS).

Description of the Activity

    Conoco seeks an IHA for conducting open-water seismic surveys 
between July 1 and November 30, 2006. The seismic vessel planned for 
use is the motor vessel (MV) Patriot. Mobilization of operations will 
occur in mid-July, and seismic operations are scheduled to begin in 
late July. Open water seismic operations are ordinarily confined to no 
more than this five-month period because of the timing of ice melt and 
formation, which typically occurs during a four to five month period. 
The geographic region of activity encompasses a 2500-3600 km\2\-area 
(965-1390 mi\2\-area) in the northeastern Chukchi Sea. The approximate 
boundaries of the region are within 158[deg]00' W. and 169[deg]00' W. 
longitude and 69[deg]00' N. and 73[deg]00' N. latitude with eastern 
boundary located parallel to the coast of Alaska, north of Point Hope 
to Point Barrow, and ranging 40-180 km (25-112 mi) off the coast. The 
nearest approximate point of the project to Point Hope is 74 km (46 
mi), Point Lay 90 km (56 mi), Wainwright 40 km (25 mi), and Barrow 48 
km (30 mi). Water depths are typically less than 50 m (164 ft).
    Conoco anticipates a work schedule of approximately 90-100 days to 
complete the planned 16,576 km (10,300 mi) of trackline, with about 30-
percent downtime due to weather, ice conditions, repairs etc. In 
addition to the primary activity of the seismic vessel, there will also 
be support vessels. A supply vessel and a fuel bunkering vessel will be 
employed to bring supplies to the seismic vessel. The seismic crew will 
most likely be changed out by helicopter and fixed-wing support may be 
used to report ice conditions if necessary.

Description of Marine 3-D Seismic Data Acquisition

    In the seismic method described here, reflected sound energy 
produces graphic images of seafloor and sub-seafloor features. The 
seismic system consists of sources and detectors, the positions of 
which must be accurately measured at all times. The sound signal comes 
from arrays of towed energy sources. These energy sources store 
compressed air which is released on command from the towing vessel. The 
released air forms a bubble which expands and contracts in a 
predictable fashion, emitting sound waves as it does so. Individual 
sources are configured into arrays. These arrays have an output signal 
which is more desirable than that of a single bubble and also serves to 
focus the sound output primarily in the downward direction which is 
useful for the seismic method. This array effect also minimizes the 
sound emitted in the horizontal direction.
    The downward propagating sound travels to the seafloor and into the 
geologic strata below the seafloor. Changes in the acoustic properties 
between the various rock layers result in a portion of the sound being 
reflected back toward the surface at each layer. This reflected energy 
is received by detectors called hydrophones, which are housed within 
submerged streamer cables (4 to 4.5-km long (2.5 to 2.8-mi long)) which 
are towed behind the seismic vessel. Data from these hydrophones are 
recorded to produce seismic records or profiles. Seismic profiles often 
resemble geologic cross-sections along the course traveled by the 
survey vessel.

Vessel and Seismic Source Specifications

    The MV Patriot is owned by Western Geco. The MV Patriot has a 
length of 78 m (256 ft), a beam of 17 m (56 ft), a maximum draft of 5.9 
m (19.4 ft), and 3586 gross tonnage. During seismic operations, the MV 
Patriot typically travels at 4-5 knots (7.4-9.2 km/hr). The MV 
Patriot's average speed when not using seismic is 12 - 15 knots (22 - 
28 km/hr).
    The energy source for the planned activity will be air gun array 
systems towed behind the vessel. There will be six to eight cables 
approximately 4 km (2.5 mi) in length spaced 100 m (328 ft) apart. Each 
source array consists of identically tuned Bolt gun sub-arrays 
operating at 2000 pounds per square inch (psi) air pressure operating 
about 8 m (26 ft) below the surface. The dominant frequency components 
are in the range of 5-70 Hz, the source level at those frequencies is 
about 209 dB, and the pulse length is 50 ms. The arrays will fire on 
interleaved 50-meter (164-ft) intervals (i.e., approximately every 15 
seconds) and they are designed to focus energy in the downward 
direction. The proposal is to have two air-gun arrays, each 
approximately 1695-in\3\ size (27,776-cm\3\)(and spaced approximately 
50 m (164 ft) apart). Together the two arrays will total approximately 
3390\3\ in (55,552-cm\3\). The airgun array will fire approximately 
every 25 m (82 ft) as the vessel is traveling at 4 to 5 knots (7.4-9.2 
km/hr). The sub-array is composed of six tuning elements; two 2-gun 
clusters and four single guns. The clusters have their component guns 
arranged in a fixed side-by-side fashion with the distance between the 
gun ports set to maximize the bubble suppression effects of clustered 
guns. A near-field hydrophone is mounted about 1 meter (3.28 ft) above 
each gun station (one phone is used per cluster), one depth transducer 
per position is mounted on the gun's ultrabox, and a high pressure 
transducer is mounted at the aft end of the sub-array to monitor high 
pressure air supply. All the data from these sensors are transmitted to 
the vessel for input into the onboard systems and recording to tape. 
See Appendix A of the application for additional information on the 
array configuration.
    Conoco will also operate two additional pieces of equipment 
throughout the planned study that emit sound at a frequency at or near 
that which a marine mammal could hear. The Simrad EA500 echo-sounder 
operates at 200 kHz, the maximum output is 185 dB re 1 microPa @ 1m, 
and the beam is directed downwards and can be up to 33[deg] wide. The 
Sonardyne SIPS-2 acoustic positioning system operates at 55-110 kHz, 
the maximum output is 183 dB re 1 Pa @ 1m, and the beam is 
omnidirectional.

Characteristics of Airgun Pulses

    Discussion of the characteristics of airgun pulses has been 
provided in the application and in previous Federal Register notices 
(see 69 FR 31792, June 7, 2004 or 69 FR 34996, June 23, 2004). 
Reviewers are referred to those documents for additional information.

Description of Marine Mammals and Habitat Affected by the Activity

    A description of the Beaufort and Chukchi sea ecosystems and their 
associated marine mammals can be found in several documents (Corps of 
Engineers, 1999; NMFS, 1999; MMS, 2006, 1996 and 1992), though NMFS 
notes that there are some data gaps regarding abundance and 
distribution of marine mammals in the Chukchi Sea (as noted in NMFS' 
Finding of No Significant Impact (FONSI)). MMS' Programmatic 
Environmental Assessment (PEA) - Arctic Ocean Outer Continental Shelf 
Seismic Surveys - 2006 may be viewed at: https://www.mms.gov/alaska/.

Marine Mammals

    A total of five cetacean species (bowhead, beluga, killer, gray, 
and

[[Page 43114]]

minke whales) and four pinniped species (ringed, bearded, spotted 
seals, and ribbon seals) are known to occur in the project area. The 
Alaska Eskimo Whaling Commission (AEWC) submitted a comment during the 
public comment period indicating that ribbon seals are occasionally 
seen in the Chukchi Sea at the time of year the seismic surveys are 
scheduled (they were not mentioned in the proposed IHA). However, 
little information is known about the abundance and distribution of 
this species during late summer and fall, local biologists present at 
the Open-water peer-review meeting in May did not raise concerns 
regarding this species, and NMFS believes that harassment of this 
species is unlikely (and authorization for this species unnecessary). 
Both minke whales and killer whales are very uncommon in the area and 
are not expected to be encountered during the seismic survey. One of 
the species, the bowhead whale, is listed as endangered under the 
Endangered Species Act (ESA). Polar bears and the Pacific walrus also 
occur in the project area, but the U.S. Fish and Wildlife Service is 
responsible for both of these species and is conducting a separate 
process under the MMPA. Therefore, they are not discussed further in 
this document.
    Table 1 includes estimated abundances and densities for the species 
expected to be potentially encountered during Conoco's seismic surveys. 
Abundance and density information for bowhead, gray, and beluga whales 
are based on the estimates provided in LGL's Healy Arctic Cruise 
Application (2005). In the Conoco application, ringed seal density was 
based on Bengston et al.'s (2005) estimates of density in the Chukchi 
Sea recorded in 1999 and 2000. Also in the Conoco application, bearded 
seal densities were obtained by adjusting the density for ringed seals 
based on the ratio of bearded to ringed seals observed during surveys 
in the Chukchi Sea by Brueggerman et al. (1990, 1991). Both the bearded 
and ringed seal densities are likely high, since Bengston et al. (2005) 
surveys included an area south of the project area, where they reported 
ringed and bearded seal densities were considerablye higher than north 
of Point Hope, which corresponds to the seismic project area. 
Accordingly, NMFS also provides the densities estimated by LGL (2005) 
for comparison. Additional information regarding the distribution of 
these species and how the estimated densities were calculated may be 
found in Conoco's application and NMFS' Updated Species Reports at: 
(https://www.nmfs.noaa.gov/pr/readingrm/MMSARS/
2005alaskasummarySARs.pdf).
BILLING CODE 3510-22-S
[GRAPHIC] [TIFF OMITTED] TN31JY06.006

Potential Effects on Marine Mammals

Summary of Potential Effects of Airgun Sounds on Marine Mammals

    Disturbance by seismic noise is the principal means of taking by 
this activity. Support vessels and aircraft may provide a potential 
secondary source of noise. The physical presence of vessels and 
aircraft could also lead to non-acoustic effects on marine mammals 
involving visual or other cues. NMFS does not expect any takings to 
result from operations of the other sound sources discussed 
(echosounder and acoustic positioning system). For the echosounder , 
produced sounds are beamed downward, the beam is narrow, the pulses are 
extremely short, and the sound source is relatively low, and with the 
acoustic postioning system, the beam is spherical, but the sound source 
is relatively low. Additionally, in the case of both of these pieces of 
equipment, the small area ensonified to a level that could potentially 
disturb marine mammals is entirely subsumed by the louder levels of 
airgun noise (which will also be running when these equipment are 
used.)
    As outlined in previous NMFS documents, the effects of noise on 
marine mammals are highly variable, and can be categorized as follows 
(based on Richardson et al., 1995):
    (1) The noise may be too weak to be heard at the location of the 
animal (i.e., lower than the prevailing ambient noise level, the 
hearing threshold of the animal at relevant frequencies, or both);
    (2) The noise may be audible but not strong enough to elicit any 
overt behavioral response;
    (3) The noise may elicit reactions of variable conspicuousness and 
variable relevance to the well being of the marine mammal; these can 
range from temporary alert responses to active avoidance reactions such 
as vacating an area at least until the noise event ceases;
    (4) Upon repeated exposure, a marine mammal may exhibit diminishing 
responsiveness (habituation), or disturbance effects may persist; the 
latter is most likely with sounds that are highly variable in 
characteristics, infrequent and unpredictable in occurrence, and 
associated with situations that a marine mammal perceives as a threat;

[[Page 43115]]

    (5) Any anthropogenic noise that is strong enough to be heard has 
the potential to reduce (mask) the ability of a marine mammal to hear 
natural sounds at similar frequencies, including calls from 
conspecifics, and underwater environmental sounds such as surf noise;
    (6) If mammals remain in an area because it is important for 
feeding, breeding or some other biologically important purpose even 
though there is chronic exposure to noise, it is possible that there 
could be noise-induced physiological stress; this might in turn have 
negative effects on the well-being or reproduction of the animals 
involved; and
    (7) Very strong sounds have the potential to cause temporary or 
permanent reduction in hearing sensitivity. In terrestrial mammals, and 
marine mammals, received sound levels must far exceed the animal's 
hearing threshold for there to be any temporary threshold shift (TTS) 
in its hearing ability. For transient sounds, the sound level necessary 
to cause TTS is inversely related to the duration of the sound. 
Received sound levels must be even higher for there to be risk of 
permanent hearing impairment. In addition, intense acoustic or 
explosive events may cause trauma to tissues associated with organs 
vital for hearing, sound production, respiration and other functions. 
This trauma may include minor to severe hemorrhage.

Effects of Seismic Surveys on Marine Mammals

    NMFS anticipates that the effects of Conoco's seismic surveys on 
marine mammals will primarily consist of behavioral disturbance, 
masking (the animals cannot hear the other sounds around them as well 
while the seismic noise is present), TTS (temporary damage to the 
auditory tissues), and low-level physiological effects.
    When the received levels of noise exceed some behavioral reaction 
threshold, cetaceans will show disturbance reactions. The levels, 
frequencies, and types of noise that will elicit a response vary 
between and within species, individuals, context, locations, and 
seasons. Behavioral changes may be subtle alterations in surface, 
respiration, and dive cycles. More conspicuous responses include 
changes in activity or aerial displays, movement away from the sound 
source, or complete avoidance of the area. The reaction threshold and 
degree of response are related to the activity of the animal at the 
time of the disturbance. Whales engaged in active behaviors, such as 
feeding, socializing, or mating, may be less likely than resting 
animals to show overt behavioral reactions, unless the disturbance is 
directly threatening.
    Although NMFS believes that some limited masking of low-frequency 
sounds (e.g., whale calls) is a possibility during seismic surveys, the 
intermittent nature of seismic source pulses (1 second in duration 
every 16 to 24 seconds, less than 7 percent)) will limit the extent of 
masking. Bowhead whales are known to continue calling in the presence 
of seismic survey sounds, and their calls can be heard between seismic 
pulses (Greene et al., 1999, Richardson et al., 1986). Masking effects 
are expected to be absent in the case of belugas, given that sounds 
important to them are predominantly at much higher frequencies than are 
airgun sounds (Western Geophysical, 2000).
    Hearing damage is not expected to occur during the Conoco seismic 
survey project. It is not positively known whether the hearing systems 
of marine mammals very close to an airgun would be at risk of temporary 
or permanent hearing impairment, but TTS is a theoretical possibility 
for animals within a few hundred meters of the source (Richardson et 
al., 1995). However, planned monitoring and mitigation measures 
(described later in this document) are designed to avoid sudden onsets 
of seismic pulses at full power, to detect marine mammals occurring 
near the array, and to avoid exposing them to sound pulses that have 
any possibility of causing hearing impairment. Moreover, as mentioned 
previously, bowhead whales avoid an area many kilometers in radius 
around ongoing seismic operations, which makes hearing damage highly 
unlikely.
    Reported species-specific responses of the marine mammals likely to 
be encountered in the survey area to seismic pulses are discussed later 
in this section. Masking, TTS, and behavioral disturbance as a result 
of exposure to low frequency sounds have been discussed in detail in 
other NMFS documents (70 FR 47797), as well as the 2006 MMS PEA.
    In addition to TTS, exposure to intense seismic sounds is likely to 
result in other physiological changes that have other consequences for 
the health and ecological fitness of marine mammals. There is mounting 
evidence that wild animals respond to human disturbance in the same way 
that they respond to predators (Beale and Monaghan, 2004; Frid, 2003; 
Frid and Dill, 2002; Gill et al., 2000; Gill and Sutherland, 2001; 
Harrington and Veitch, 1992; Lima, 1998; Romero, 2004). These responses 
manifest themselves as interruptions of essential behavioral or 
physiological events, alteration of an animal's time or energy budget, 
or stress responses in which an animal perceives human activity as a 
potential threat and undergoes physiological changes to prepare for a 
flight or fight response or more serious physiological changes with 
chronic exposure to stressors (Frid and Dill, 2002; Romero, 2004; 
Sapolsky et al., 2000; Walker et al., 2005).
    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Sapolsky et al., 2005; Seyle, 1950). Once an 
animal's central nervous system perceives a threat, it develops a 
biological response or defense that consists of a combination of the 
four general biological defense responses: behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
response.
    The physiological mechanisms behind stress responses involving the 
hypothalamus-pituitary-adrenal glands have been well-established 
through controlled experiment in the laboratory and natural settings 
(Korte et al., 2005; McEwen and Seeman, 2000; Moberg, 1985; 2000; 
Sapolsky et al., 2005). Relationships between these physiological 
processes, animal behavior, neuroendocrine responses, immune responses, 
inhibition of reproduction (by suppression of pre-ovulatory luteinizing 
hormones), and the costs of stress responses have also been documented 
through controlled experiment in both laboratory and free-living 
animals (for examples see, Holberton et al., 1996; Hood et al., 1998; 
Jessop et al., 2003; Krausman et al., 2004; Lankford et al., 2005; 
Reneerkens et al., 2002; Thompson and Hamer, 2000; Tilbrook et al., 
2000).
    The available evidence suggests that: with the exception of 
unrelieved pain or extreme environmental conditions, in most animals 
(including humans) chronic stress results from exposure to a series of 
acute stressors whose cumulative biotic costs produce a pathological or 
pre-pathological state in an animal. The biotic costs can result from 
exposure to an acute stressor or from the accumulation of a series of 
different stressors acting in concert before the animal has a chance to 
recover.
    Although few of these responses have been explicitly identified in 
marine mammals, they have been identified in

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other vertebrate animals and every vertebrate mammal that has been 
studied, including humans. Because of the physiological similarities 
between marine mammals and other mammal species, NMFS believes that 
acoustic energy sufficient to trigger onset TTS is likely to initiate 
physiological stress responses. More importantly, NMFS believes that 
marine mammals might experience stress responses at received levels 
lower than those necessary to trigger onset TTS, and that some of these 
stress responses rise to the level of Harassment.
    The following species summaries are provided by NMFS to facilitate 
understanding of our knowledge of impulsive noise impacts on the 
principal marine mammal species that are expected to be affected.

Bowhead Whales

    Seismic pulses are known to cause strong avoidance reactions by 
many of the bowhead whales occurring within a distance of a few 
kilometers, including changes in surfacing, respiration and dive 
cycles, and may sometimes cause avoidance or other changes in bowhead 
behavior at considerably greater distances (Richardson et al., 1995; 
Rexford, 1996; MMS, 1997). Studies conducted prior to 1996 (Reeves et 
al., 1984, Fraker et al., 1985, Richardson et al., 1986, Ljungblad et 
al., 1988) have reported that, when an operating seismic vessel 
approaches within a few kilometers, most bowhead whales exhibit strong 
avoidance behavior and changes in surfacing, respiration, and dive 
cycles. In these studies, bowheads exposed to seismic pulses from 
vessels more than 7.5 km (4.7 mi) away rarely showed observable 
avoidance of the vessel, but their surface, respiration, and dive 
cycles appeared altered in a manner similar to that observed in whales 
exposed at a closer distance (Western Geophysical, 2000). In three 
studies of bowhead whales and one of gray whales during this period, 
surfacing-dive cycles were unusually rapid in the presence of seismic 
noise, with fewer breaths per surfacing and longer intervals between 
breaths (Richardson et al.,1986; Koski and Johnson,1987; Ljungblad et 
al.,1988; Malme et al.,1988). This pattern of subtle effects was 
evident among bowheads 6 km (3mi) to at least 73 km (3.7 to 45.3 mi) 
from seismic vessels. However, in the pre-1996 studies, active 
avoidance usually was not apparent unless the seismic vessel was closer 
than about 6 to 8 km (3.7 to 5.0 mi)(Western Geophysical, 2000).
    Conoco's seismic survey will occur during a time when bowhead 
whales are migrating west from Canada back across the North Slope of 
Alaska. Results from the 1996-1998 BP and Western Geophysical seismic 
program monitoring in the Beaufort Sea indicate that most migrating 
bowheads deflected seaward to avoid an area within about 20 km (12.4 
mi) of an active nearshore seismic operation, with the exception of a 
few closer sightings when there was an island or very shallow water 
between the seismic operations and the whales (Miller et al., 1998, 
1999). The available data do not provide an unequivocal estimate of the 
distance at which approaching bowheads begin to deflect, but this may 
be on the order of 35 km (21.7 mi). It is also uncertain how far beyond 
(west of) the seismic operation the seaward deflection persists (Miller 
et al., 1999). Although very few bowheads approached within 20 km (12.4 
mi) of the operating seismic vessel, the number of bowheads sighted 
within that area returned to normal within 12-24 hours after the airgun 
operations ended (Miller et al.,1999).
    Inupiat whalers believe that migrating bowheads are sometimes 
displaced at distances considerably greater than suggested by pre-1996 
scientific studies (Rexford, 1996) previously mentioned in this 
document. Also, whalers believe that avoidance effects can extend out 
to distances on the order of 30 miles (48.3 km), and that bowheads 
exposed to seismic also are ``skittish'' and more difficult to 
approach. The ``skittish'' behavior may be related to the observed 
subtle changes in the behavior of bowheads exposed to seismic pulses 
from distant seismic vessels (Richardson et al., 1986).

Gray Whales

    The reactions of gray whales to seismic pulses are similar to those 
documented for bowheads during the 1980s. Migrating gray whales along 
the California coast were noted to slow their speed of swimming, turn 
away from seismic noise sources, and increase their respiration rates. 
Malme et al. (1983, 1984, 1988) concluded that approximately 50 percent 
of the migrating gray whales showed avoidance when the average received 
pulse level was 170 dB (re 1 microPa). By some behavioral measures, 
clear effects were evident at average pulse levels of 160 dB or 
greater; less consistent results were suspected at levels of 140-160 
dB. Recent research on migrating gray whales showed responses similar 
to those observed in the earlier research when the source was moored in 
the migration corridor 2 km (1.2 mi) from shore. However, when the 
source was placed offshore (4 km (2.5 mi) from shore) of the migration 
corridor, the avoidance response was not evident on track plots (Tyack 
and Clark, 1998).

Beluga

    The beluga is the only species of toothed whale (odontocete) 
expected to be encountered in the Beaufort Sea. Belugas have poor 
hearing thresholds at frequencies below 200 Hz, where most of the 
energy from airgun arrays is concentrated. Their thresholds at these 
frequencies (as measured in a captive situation), are 125 dB re 1 
microPa or more depending upon frequency (Johnson et al., 1989). 
Although not expected to be significantly affected by the noise, given 
the high source levels of seismic pulses, airgun sounds sometimes may 
be audible to belugas at distances of 100 km (62.1 mi) (Richardson and 
Wursig, 1997), and perhaps further if actual low-frequency hearing 
thresholds in the open sea are better than those measured in captivity 
(Western Geophysical, 2000). The reaction distance for belugas, 
although presently unknown, is expected to be less than that for 
bowheads, given the presumed poorer sensitivity of belugas than that of 
bowheads for low-frequency sounds.
    As noted in the MMS PEA, effects on the immune system from seismic 
pulses have been documented by Romano et al. (2004). They summarized 
that ``anthropogenic sound is a potential ``stressor'' for marine 
mammals. Not only can loud or persistent noise impact the auditory 
system of cetaceans, it may impact health by bringing about changes in 
immune function, as has been shown in other mammals'' These authors 
identified neural immune measurements that may be ``implicated as 
indicates of stress in a beluga and bottlenose dolphin that were either 
released acutely or changed over time during experimental period.'' 
Specifically, they found significant increases in aldosterone and a 
significant decrease in monocytes in a bottlenose dolphin after 
exposure to single impulsive sounds (up to 200 kiloPascals (kPa)) from 
a seismic water gun. Neural-immune changes following exposure to single 
pure tones (up to 201 dB re 1 microPa) resembling sonar pings were 
minimal, but changes were observed over time. A beluga whale exposed to 
single underwater impulses produced by a seismic water gun had 
significantly higher norepinephrine, dopamine and epinephrine levels 
after high-level sound exposure (>100 kPa) as compared with low-level 
exposures (<100kPa) or controls and increased with increasing sound 
levels.

[[Page 43117]]

Ringed, Spotted and Bearded Seals

    No detailed studies of reactions by seals to noise from open water 
seismic exploration have been published (Richardson et al., 1995). 
However, there are some data on the reactions of seals to various types 
of impulsive sounds (LGL and Greeneridge, 1997, 1998, 1999a; J. Parsons 
as quoted in Greene, et al., 1985; Anon., 1975; Mate and Harvey, 1985). 
These studies indicate that ice seals typically either tolerate or 
habituate to seismic noise produced from open water sources.
    Underwater audiograms have been obtained using behavioral methods 
for three species of phocinid seals, ringed, harbor, and harp seals 
(Pagophilus groenlandicus). These audiograms were reviewed in 
Richardson et al. (1995) and Kastak and Schusterman (1998). Below 30-50 
kHz, the hearing threshold of phocinids is essentially flat, down to at 
least 1 kHz, and ranges between 60 and 85 dB (re 1 microPa @ 1 m). 
There are few data on hearing sensitivity of phocinid seals below 1 
kHz. NMFS considers harbor seals to have a hearing threshold of 70-85 
dB at 1 kHz (60 FR 53753, October 17, 1995), and recent measurements 
for a harbor seal indicate that, below 1 kHz, its thresholds 
deteriorate gradually to 97 dB (re 1 microPa @ 1 m) at 100 Hz (Kastak 
and Schusterman, 1998).
    While no detailed studies of reactions of seals from open-water 
seismic exploration have been published (Richardson et al., 1991, 
1995), some data are available on the reactions of seals to various 
types of impulsive sounds (see LGL and Greeneridge, 1997, 1998, 1999a; 
Thompson et al., 1998). These references indicate that it is unlikely 
that pinnipeds would be harassed or injured by low frequency sounds 
from a seismic source unless they were within relatively close 
proximity of the seismic array. For permanent injury, pinnipeds would 
likely need to remain in the high-noise field for extended periods of 
time. Existing evidence also suggests that, while seals may be capable 
of hearing sounds from seismic arrays, they appear to tolerate intense 
pulsatile sounds without known effect once they learn that there is no 
danger associated with the noise (see, for example, NMFS/Washington 
Department of Wildlife, 1995). In addition, they will apparently not 
abandon feeding or breeding areas due to exposure to these noise 
sources (Richardson et al., 1991) and may habituate to certain noises 
over time.

Safety Radii

    NMFS has determined that for acoustic effects, using established 
acoustic thresholds in combination with corresponding safety radii is 
the most effective way to consistently both apply measures to avoid or 
minimize the impacts of an action and to quantitatively estimate the 
effects of an action. NMFS believes that cetaceans and pinnipeds should 
not be exposed to pulsed underwater noise at received levels exceeding, 
respectively, 180 and 190 dB re 1 microPa (rms) to avoid permanent 
physiological damage (Level A Harassment). NMFS also assumes that 
cetaceans or pinnipeds exposed to levels exceeding 160 dB re 1 microPa 
(rms) experience Level B Harassment. Thresholds are used in two ways: 
(1) To establish a mitigation shut-down or power down zone, i.e., if an 
animal enters an area calculated to be ensonified above the level of an 
established threshold, a sound source is powered down or shut down; and 
(2) to calculate take, in that a model may be used to calculate the 
area around the sound source that will be ensonified to that level or 
above, then, based on the estimated density of animals and the distance 
that the sound source moves, NMFS can estimate the number of marine 
mammals that may be ``taken''.
    In order to implement shut-down zones, or to estimate how many 
animals may potentially be exposed to a particular sound level using 
the acoustic thresholds described above, it is necessary to understand 
how sound will propagate in a particular situation. Models may be used 
to estimate at what distance from the sound source the water will be 
ensonified to a particular level. Safety radii represent the estimated 
distance from the sound source at which the received level of sound 
would be 190, 180, and 160 dB.
    Conoco's application contains their initial proposed safety radii 
and take estimates. However, the initial model Conoco used did not take 
into consideration either the physical characteristics of the Chukchi 
Sea or the fact that the water was only 50-m (164-ft) deep, and NMFS 
was concerned that the proposed radii were too small. Subsequently, 
Conoco adopted a new model and submitted new proposed safety and take 
estimates. They used an advanced airgun array source model to predict 
the 190, 180, and 160 dB isopleths for the seismic survey in the 
Chukchi Sea. This model simulates the throttled injection of high-
pressure air from airgun chambers into underwater air bubbles, 
simulates the complex oscillation of each bubble, taking into account 
the hydrostatic pressure effects of the pressure waves from all other 
airguns, and includes effects such as surface-reflected pressure waves, 
heat transfer from bubble to the surrounding water, and the buoyancy of 
the bubbles. The model also takes into consideration the bathymetry, 
water properties, and geoacoustic properties of the sea bed layers in 
the survey area. The calculated safety radii from this model are as 
follows: the 190-dB radius is 230 m (754 ft), the 180-dB radius is 850 
m (2,788), and the 160-dB radius is 4,590 m (2.85 mi).
    Though the model considers some of the site-specific 
characteristics of the Chukchi Sea, because no sound propagation 
studies have previously been conducted in the survey area (against 
which model results can be prepared) NMFS believes that it is 
appropriate and necessary to field-verify the modeled safety radii. 
Accordingly, field verification will be conducted prior to initiation 
of the seismic survey and, until that time, Conoco will multiply the 
modeled 190-dB and 180-dB safety radii by 1.5 (which equals 345 m (1121 
ft) and 1,275 m (4, 174 ft), respectively) to conservatively establish 
the mitigation shutdown zones for marine mammals (see Mitigation 
section). The 1.5 correction factor will not be used in the take 
estimations and will not be used after the radii are field-verified.
    Field verification will be conducted using an autonomous ocean 
bottom hydrophone. This hydrophone is suspended (upward, by float) from 
an anchor dropped to the ocean floor, and then released to the surface 
for data collection when a particular frequency tone is directed at the 
hydrophone. The MV Patriot will run directly, in a straight line, at, 
over, and past the hydrophone to establish received sound levels at 
distances in front of and behind the sound source. Then, the MV Patriot 
will do a lawnmower type zig-zag sideways to the hydrophone so that 
received levels at varying distances to the side of the sound source 
may be measured. Because of the shape of the array, sound propagates 
farther laterally from the source than forward or backward, so both 
orientations are measured, then a conservative combination of the two 
is used to calculate the safety radii. NMFS will use the field verified 
safety radii to establish power-down and shut-down zones for the MV 
Patriot.

[[Page 43118]]

Estimated Take by Incidental Harassment for Conoco's Seismic Survey

    Given the required mitigation (see Mitigation later in this 
document), NMFS anticipates that takes will consist of Level B 
harassment, at most. The required mitigation measures are expected to 
minimize or eliminate the possibility of Level A harassment or 
mortality. Additionally, these numbers do not take into consideration 
either the effectiveness of the mitigation measures or the fact that 
some species will avoid the sound source at distances greater than 
those estimated to result in a take.
    It is difficult to make accurate, scientifically robust, and 
observationally verifiable estimates of the number of individuals 
likely to be subject to Level B Harassment by the noise from Conoco's 
airguns. There are many uncertainties: in seasonally varying abundance, 
in local horizontal and vertical distribution; in marine mammal 
reactions to varying frequencies and levels of acoustic pulses; and in 
perceived sound levels at different horizontal and oblique ranges from 
the source.
    NMFS believes the best estimate of potential ``take by harassment'' 
is derived by multiplying the estimated densities (per square 
kilometer) of each species within the survey area by the width of the 
160-dB safety radii (4,590 m (2.85 mi)) over the length of Conoco's 
estimated trackline (16,576 km (10,300 mi)). Since Conoco revised its 
safety radii after submitting their application, the estimated take 
numbers presented here are higher than those predicted in its 
application. The total maximum estimated ``take by harassment'' is 
presented in Table 1. As mentioned previously, the upper limit of 
estimated take for ringed and bearded seals suggested in Table 1 is 
most likely an overestimate, as it is based on surveys of the animals 
conducted nearer to shore, where densities are higher than they are 
off-shore where the seismic surveys will be conducted. Additionally, 
the stocks of both of these animals are thought to extend throughout 
Arctic and the abundance estimates discussed here are minimum 
abundances.

Potential Effects on Habitat

    Conoco states that the seismic survey will not cause any permanent 
impact on habitats and the prey used by marine mammals. A broad 
discussion on the various types of potential effects of exposure to 
seismic on fish and invertebrates can be found in LGL (2005; University 
of Alaska-Fairbanks Seismic Survey across Arctic Ocean at https://
www.nmfs.noaa.gov/pr/permits/incidental.htm#iha), and includes a 
summary of direct mortality (pathological/ physiological) and indirect 
(behavioral) effects.
    Mortality to fish, fish eggs and larvae from seismic energy sources 
would be expected within a few meters (0.5 to 3 m (1.6 to 9.8 ft)) from 
the seismic source. Direct mortality has been observed in cod and 
plaice within 48 hours of being subjected to seismic pulses two meters 
from the source (Matishov, 1992), however other studies did not report 
any fish kills from seismic source exposure (La Bella et al., 1996; 
IMG, 2002; Hassel et al., 2003). To date, fish mortalities associated 
with normal seismic operations are thought to be slight. Saetre and Ona 
(1996) modeled a worst-case mathematical approach on the effects of 
seismic energy on fish eggs and larvae, and concluded that mortality 
rates caused by exposure to seismic are so low compared to natural 
mortality that issues relating to stock recruitment should be regarded 
as insignificant.
    Limited studies on physiological effects on marine fish and 
invertebrates to acoustic stress have been conducted. No significant 
increases in physiological stress from seismic energy were detected for 
various fish, squid, and cuttlefish (McCauley et al., 2000) or in male 
snow crabs (Christian et al., 2003). Behavioral changes in fish 
associated with seismic exposures are expected to be minor at best. 
Because only a small portion of the available foraging habitat would be 
subjected to seismic pulses at a given time, fish would be expected to 
return to the area of disturbance anywhere from 15-30 minutes (McCauley 
et al., 2000) to several days (Engas et al., 1996).
    Available data indicates that mortality and behavioral changes do 
occur within very close range to the seismic source, however, the 
scheduled seismic acquisition activities in the Chukchi are predicted 
by Conoco to have a negligible effect to the prey resource of the 
various life stages of fish and invertebrates available to marine 
mammals occurring during the project's duration. The planned Conoco 
trackline is 16,576 km (10,300 ft) long, and will encompass 
approximately a 2500-3600 km2-area (965-1390 mi2-area) in the 
northeastern Chukchi Sea. Only a small fraction of the available 
habitat would be impacted by noise at any given time during the seismic 
surveys, and the constant movement of the seismic vessel would prevent 
any area from sustaining high noise levels for extended periods of 
time. Disturbance to fish species would most likely be short-term and 
temporary. Thus, Conoco's activity is not expected to have any effects 
on habitat or prey that could cause permanent or long-term consequences 
for individual marine mammals or their populations, since operations 
will be limited in duration, location, timing, and intensity.

Potential Effects on Subsistence Use of Marine Mammals

    Marine mammals are key in the subsistence economies of the 
communities bordering the seismic survey area, including Barrow, 
Wainwright, Point Lay, and Point Hope. Other communities that subsist 
on marine mammals are considerably beyond the project area, and their 
subsistence activities are unlikely to be affected by the seismic 
operations in the Chukchi Sea. The whale harvests have a great 
influence on social relations by strengthening the sense of Inupiat 
culture and heritage in addition to reinforcing family and community 
ties.
    Bowhead whales are important for subsistence at all of the villages 
bordering the project area except Point Lay, which does not hunt 
bowhead whales. The harvest is based on a quota, established by the 
International Whaling Commission (IWC ) and regulated by agreement 
between AEWC and NMFS, according to the cultural and nutritional needs 
of Alaska Eskimos as well as on estimates of the size and growth of the 
stock of bowhead whales (Suydam and George, 2004). In 2002 the IWC set 
a 5-year block quota of 67 strikes per year with a total landed not to 
exceed 280 whales (IWC 2003). The most recent data show that 37, 35, 
and 36 whales were landed in 2000-2004 for a total of 108 whales 
(Suydam and George 2004, Suydam et al. 2005). Between 23 and 28 were 
taken at Point Hope, Wainwright, and Barrow during these years, with 
most (60-90 percent) taken by Barrow each year.
    Bowheads are hunted during the spring and fall migrations. Barrow 
hunts during the spring and fall migrations. Historically, Point Hope 
and Wainwright have predominantly hunted during the spring migration, 
however, due to changes in the Arctic weather and sea ice conditions 
they plan to also undertake fall whaling beginning this year. Barrow 
takes most bowheads during the spring migration. The spring bowhead 
hunt occurs after leads open due to the deterioration of pack ice, 
which typically occurs from early April until the first week of June. 
Because of the timing, the spring hunts of Point Hope, Wainwright, and 
Barrow should not be affected by seismic operation,

[[Page 43119]]

since the hunt should be completed before the start of seismic 
operations in July.
    The autumn hunt at Barrow usually begins in mid-September, and 
mainly occurs in the waters east and northeast of Point Barrow in the 
Beaufort Sea. The whales have usually left the Beaufort Sea by late 
October (Treacy, 2002a,b). The location of the fall hunt depends on ice 
conditions, which can influence distance of whales from shore (Brower, 
1996). Hunters prefer to take bowheads close to shore to avoid a long 
tow during which the meat can spoil, but Braund and Moorehead (1995) 
report that crews may (rarely) pursue whales as far as 80 km (50 mi), 
and in 2004 hunters harvested a whale up to 50 km (31 mi) northeast of 
Barrow (Suydam et al., 2005).
    Beluga whales are hunted for subsistence at Barrow, Wainwright, 
Point Lay, and Point Hope, with the most taken by Point Lay (Fuller and 
George 1997). Point Lay harvests belugas primarily during summer in 
Kasegaluk Lagoon, where they averaged 40 belugas per year over a 10-
year period (Fuller and George, 1997). Compared to Point Lay, small 
numbers of belugas are harvested by Barrow with intermediate numbers 
harvested by Point Hope and Wainwright. Harvest at these villages 
generally occurs between April and July, with most taken in April and 
May when pack-ice conditions deteriorate and leads open up. Hunters 
usually wait until after the bowhead whale hunt to hunt belugas. The 
Alaska Beluga Whale Committee recorded 23 beluga whales harvested by 
Barrow hunters from 1987 to 2002, ranging from 0 in 1987, 1988 and 1995 
to the high of 8 in 1997 (Fuller and George, 1999; Alaska Beluga Whale 
Committee 2002 in USDI/BLM 2005). The time of the project will not 
overlap hunts at Point Hope, Wainwright, and Barrow, and in any event 
Point Hope and Barrow should be largely beyond any influence of the 
project activities. Point Lay villagers hunt in Kasegaluk Lagoon, which 
is beyond the influence of the project activities. Furthermore, the 
lagoon is shallow and close to shore, which would greatly reduce any 
underwater seismic noise, in the unlikely event noise reached the 
lagoon.
    Ringed, bearded, and spotted seals are hunted by all of the 
villages bordering the project area (Fuller and George, 1997). Ringed 
seals comprise the largest part of the subsistence hunt and spotted 
seal the least, particularly at Barrow where they are primarily hunted 
near shore. Spotted seals are considerably more abundant in the Chukchi 
than Beaufort Sea. At Barrow, spotted seals are primarily hunted in 
Admiralty Bay, which is about 60 km east of Barrow. The largest 
concentrations of spotted seals in Alaska are in Kasegaluk Lagoon, 
where Point Lay hunters harvest them. (Frost et al. 1993). Braund et 
al. (1993) found that the majority of bearded seals taken by Barrow 
hunters are within approximately 24 km (15 mi) off shore. Ringed and 
bearded seals are hunted throughout the year, but most are taken in 
May, June, and July when ice breaks up and there is open water instead 
of the more difficult hunting of seals at holes and lairs. The timing 
slightly varies among villages, with peak hunting occurring 
incrementally later going from Point Hope to Barrow. Spotted seals are 
only hunted in spring through summer, since they winter in the Bering 
Sea. The seismic operation should have little to no effect on 
subsistence hunting since the seismic survey will no more than 
minimally overlap the end of the primary period when seals are 
harvested, and most hunting at the villages will be a considerable 
distance away from seismic operations, particularly at Point Hope (74 
km (46 mi)) and Point Lay (90 km (56 mi)).
    Natives in Alaska are very concerned about how seismic operations 
in the Chukchi Sea will impact their subsistence harvest of marine 
mammals. NMFS shares these concerns and some of the studies presented 
in the Effects section of this document further validate them. NMFS 
notes, though, that some of the types of behaviors that may affect the 
subsistence harvest may not be considered ``harassment'' (such as a 
minor migration route deflection ). Following are a few of their 
primary concerns:
    (1) Native knowledge suggests that sound from seismic surveys may 
cause bowhead whales or other subsistence stocks to change their 
behavior or migratory patterns in such a way that they are not present 
in traditional hunting grounds or in historical numbers. If so, natives 
may be unable to harvest any animals, or will have to harvest them from 
such a distance that the animal may spoil during the long tow back and 
human safety risks are increased during the extended trip.
    (2) Native knowledge indicates that bowhead whales become 
increasingly ``skittish'' in the presence of seismic noise. Whales are 
more wary around the hunters and tend to expose a much smaller portion 
of their back when surfacing (which makes harvesting more difficult). 
Additionally, natives report that bowheads exhibit angry behaviors in 
the presence of seismic activity, such as tail-slapping, which 
translates to danger for nearby subsistence harvesters.
    (3) Natives are concerned that the cumulative effects of increased 
numbers of concurrent seismic surveys in the Chukchi and Beaufort Seas 
may have population-level effects on subsistence stocks that will 
permanently affect their subsistence harvest. An additional concern is 
the perception by the IWC of the increased risk of population-level 
effects, which could lead to lower, or even no subsistence quotas for 
Alaska Natives.

Plan of Cooperation

    Regulations at 50 CFR 216.104(a)(12)(i) require IHA applicants for 
activities that take place in Arctic waters to provide a plan of 
cooperation (POC) or information that identifies what measures have 
been taken and/or will be taken to minimize any adverse effects on the 
availability of marine mammals for subsistence uses. Representatives of 
Conoco have been in continued coordination with the AEWC and met with 
the whaling captains of the potentially affected villages in March, 
2006. Additionally, both Conoco and the AEWC had representatives 
present at the Open-Water Seismic meeting held in Alaska in April and 
further negotiated appropriate measures to minimize impacts to the 
subsistence harvest.
    Conoco has signed a Conflict Avoidance Agreement (CAA) with the 
AEWC. The CAA incorporates all appropriate measures and procedures 
regarding the timing and areas of the operator's planned activities 
(i.e., times and places where seismic operations will be curtailed or 
moved in order to avoid potential conflicts with active subsistence 
whaling and sealing); communications system between operator's vessels 
and whaling and hunting crews; provisions for marine mammal observers/
Inupiat communicators aboard all project vessels; conflict resolution 
procedures; and provisions for rendering emergency assistance to 
subsistence hunting crews.
    Based on the contents of the signed CAA, as well as additional 
mitigation and monitoring measures discussed later in this document 
(see Mitigation), NMFS has determined that the Conoco's seismic survey 
will not have an unmitigable adverse impact on the subsistence harvest 
of the affected species or stocks.

Comments and Responses

    On May 12, 2006 (71 FR 27685), NMFS published a notice of a 
proposed IHA for Conoco's request to take marine mammals incidental to 
conducting

[[Page 43120]]

open-water seismic surveys in the Chukchi Sea, and requested comments, 
information and suggestions concerning the request. During the 30-day 
public comment period, NMFS received comments from one private citizen 
and several sets of comments from non-governmental organizations, 
including the Center for Biological Diversity (CBD) (which were also on 
behalf of EarthJustice, Pacific Environment, Alaska Coalition, Alaska 
Wilderness League, the Natural Resources Defense Council (NRDC), 
Greenpeace, Inc., Oceana, and the Northern Alaska Environmental 
Center), joint comments from the AEWC and the North Slope Borough (NSB) 
Department of Wildlife Management, the Native Village of Point Hope, 
Conoco Phillips Alaska, Inc., and the Alaska Oil and Gas Association 
(AOGA).
    Comment 1: AOGA asked comments they submitted addressing the PEA be 
inserted into the admin record for the IHA. CBD suggested that NRDC's 
comments on the PEA also be considered for the issuance of the IHA.
    Response: These comments have been considered in the Final PEA and 
in NMFS' and MMS' FONSIs. Many of the comments are specific to the PEA. 
However, where either of these sets of comments raise issues germane to 
the IHA issue that have not been addressed already, NMFS has addressed 
them in this section.
    Comment 2: The Marine Mammal Commission submitted comments on the 
Shell open-water seismic survey IHA application that also reference the 
Conoco application.
    Response: These comments are addressed in the Federal Notice 
announcing the issuance of the Shell IHA.
    Comment 3: One commenter recommends NMFS deny an IHA to Shell 
unless and until NMFS can ensure that mitigation measures are in place 
to truly avoid adverse impacts to all species and their habitats.
    Response: The requirements of the MMPA are that impacts be reduced 
to the lowest level practicable, not that no adverse impacts be 
allowed. NMFS believes that the mitigation measures required under 
Shell's IHA will reduce levels to the lowest level practicable.
    Comment 4: The CBD states that NMFS' failure to address the 
scientific literature linking seismic surveys with marine mammal 
stranding events, and the threat of serious injury or mortality renders 
NMFS' conclusionary determination that serious injury or mortality will 
not occur from Shell's activities arbitrary and capricious.
    Response: The evidence linking marine mammal strandings and seismic 
surveys remains inconclusive at best. Two papers, Taylor et al. (2004) 
and Engel et al. (2004) reference seismic signals as a possible cause 
for a marine mammal stranding. Taylor et al. (2004) noted two beaked 
whale stranding incidents related to seismic surveys. The statement in 
Taylor et al. (2004) was that the seismic vessel was firing its airguns 
at 1300 hrs on September 24, 2004 and that between 1400 and 1600 hrs, 
local fishermen found live-stranded beaked whales some 22 km (12 nm) 
from the ship's location. A review of the vessel's trackline indicated 
that the closest approach of the seismic vessel and the beaked whales 
stranding location was 18 nm (33 km) at 1430 hrs. At 1300 hrs, the 
seismic vessel was located 25 nm (46 km) from the stranding location. 
What is unknown is the location of the beaked whales prior to the 
stranding in relation to the seismic vessel, but the close timing of 
events indicates that the distance was not less than 18 nm (33 km). No 
physical evidence for a link between the seismic survey and the 
stranding was obtained. In addition, Taylor et al. (2004) indicates 
that the same seismic vessel was operating 500 km (270 nm) from the 
site of the Galapagos Island stranding in 2000. Whether the 2004 
seismic survey caused to beaked whales to strand is a matter of 
considerable debate (see Cox et al., 2004). NMFS believes that 
scientifically, these events do not constitute evidence that seismic 
surveys have an effect similar to that of mid-frequency tactical sonar. 
However, these incidents do point to the need to look for such effects 
during future seismic surveys. To date, follow-up observations on 
several scientific seismic survey cruises have not indicated any beaked 
whale stranding incidents.
    Engel et al. (2004), in a paper presented to the IWC in 2004 (SC/
56/E28), mentioned a possible link between oil and gas seismic 
activities and the stranding of 8 humpback whales (7 off the Bahia or 
Espirito Santo States and 1 off Rio de Janeiro, Brazil). Concerns about 
the relationship between this stranding event and seismic activity were 
raised by the International Association of Geophysical Contractors 
(IAGC). The IAGC (2004) argues that not enough evidence is presented in 
Engel et al. (2004) to assess whether or not the relatively high 
proportion of adult strandings in 2002 is anomalous. The IAGC contends 
that the data do not establish a clear record of what might be a 
``natural'' adult stranding rate, nor is any attempt made to 
characterize other natural factors that may influence strandings. As 
stated previously, NMFS remains concerned that the Engel et al. (2004) 
article appears to compare stranding rates made by opportunistic 
sightings in the past with organized aerial surveys beginning in 2001. 
If so, then the data are suspect.
    Second, strandings have not been recorded for those marine mammal 
species expected to be harassed by seismic in the Arctic Ocean. Beaked 
whales and humpback whales, the two species linked in the literature 
with stranding events with a seismic component are not located in the 
Cukchi Sea seismic area. Finally, if bowhead and gray whales react to 
sounds at very low levels by making minor course corrections to avoid 
seismic noise and mitigation measures require Shell to ramp-up the 
seismic array to avoid a startle effect, strandings are highly unlikely 
to occur in the Arctic Ocean. In conclusion, NMFS does not expect any 
marine mammals will incur injury or mortality as a result of Arctic 
Ocean seismic surveys in 2006.
    Comment 5: Several commenters list concerns regarding cumulative 
effects (including the other scheduled seismic surveys, activities in 
other areas, and global warming, among other things) and to what extent 
they were considered in NMFS negligible impact determination for this 
IHA.
    Response: Under section 101(a)(5)(D) of the MMPA, ``the Secretary 
shall authorize... taking by harassment of small numbers of marine 
mammals of a species or population stock by such citizens while 
engaging in that activity within that region if the Secretary finds 
that such harassment during each period concerned (I) will have a 
negligible impact on such species or stock, and (II) will not have an 
unmitigable adverse impact on the availability of such species or stock 
for taking for subsistence uses.'' NMFS cannot make a negligible impact 
determination for an IHA under this provision of the MMPA based on the 
cumulative effects of other actions.
    As stated previously, cumulative impact assessments are NMFS' 
responsibility under NEPA, not the MMPA. In that regard, the MMS' Final 
PEA addresses cumulative impacts, as did its Draft PEA. The PEA's 
cumulative activities scenario and cumulative impact analysis focused 
on oil and gas-related and non-oil and gas-related noise-generating 
events/activities in both Federal and State of Alaska waters that were 
likely and foreseeable. Other appropriate factors, such as Arctic 
warming, military activities and noise

[[Page 43121]]

contributions from community and commercial activities were also 
considered. Appendix D of that PEA addresses similar comments on 
cumulative impacts, including global warming. That information is 
incorporated in this document by citation. NMFS has adopted the MMS 
Final PEA as its own NEPA document (see NEPA later in this document) 
and is part of its Administrative Record.
    Additionally, NMFS and MMS considered the potential for cumulative 
impacts in the development of the mitigation measures in the PEA and, 
because of the need to avoid significance pursuant to NEPA, several 
additional protective measures (such as expanded shutdown zones and a 
research monitoring plan) meant to address these concerns, as well as 
the uncertainty, have been incorporated into the IHA.
    Comment 6: The CBD believes that NMFS cannot issue an IHA to Conoco 
because it has not complied with the MMPA's requirement to specify the 
specific geographic region where the activity will occur.
    Response: NMFS defines ``specified geographical region'' as ``an 
area within which a specified activity is conducted and which has 
certain biogeographic characteristics'' (50 CFR 216.103). NMFS believes 
that Conoco's description of the activity and the locations for 
conducting seismic surveys meet the requirements of the MMPA. Conoco 
has provided a well-defined area, within which certain biogeographic 
characteristics occur (the entire area is approximately 50-m (164-ft) 
deep or less), in which they will conduct their operations. More 
specific locations within the Lease Sale area described are considered 
proprietary.
    Comment 7: Commenters say that NMFS does not have evidence to 
support an unmitigable adverse impact to subsistence hunting finding 
and point out that Kaktovik and Point Hope have passed resolutions 
opposing offshore oil development.
    Response: NMFS acknowledges that these villages have passed 
resolutions objecting to offshore oil development. However, the village 
whaling captains of these villages (in addition to villages of Nuiqsuk 
and Wainwright and the AEWC) have signed a CAA indicating to NMFS that 
there will not be an unmitigable adverse impact on subsistence uses of 
marine mammals. This is discussed in detail later in this document (see 
Impact on Subsistence).
    Comment 8: Commenters state that because the MMPA explicitly 
requires that ``means effecting the least practicable impact'' on the 
species, stock or habitat be included [in mitigation measures], an IHA 
[notice] must explain why measures that would reduce the impact on a 
species were not chosen (i.e., why they were not practicable). Neither 
the proposed IHA [notice], Conoco's application, nor the PEA attempt to 
do this.
    Response: Neither the MMPA nor NMFS regulations implementing the 
incidental take program require NMFS to itemize and discuss all 
measures that were determined to be impracticable. Such an effort can 
quickly become a matter of speculation. For example, drones, manned 
balloons, and satellites are currently considered impracticable for 
technological and safety reasons and usually need not be discussed in 
issuing IHAs. Helicopters and other aircraft may be practicable 
depending upon distance between lan