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

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 [Federal Register: July 31, 2006 (Volume 71, Number 146)]
[Notices]
[Page 43112-43132]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr31jy06-38]

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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: http://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 
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, 
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: http://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: 
(http://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

[[Page 43116]]

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 
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 
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 
http://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 landing and activity location, weather 
and safety and are usually discussed if safety zones cannot be visually 
monitored effectively. Also, active and passive acoustics are often 
discussed when issuing an IHA if the safety zone cannot be visually 
monitored effectively. Time and area closures or restrictions are 
discussed when appropriate. In many cases, monitoring larger zones to 
simply reduce the Level B harassment take, is viewed as secondary to 
effectively monitor the Level A harassment zone, in order to prevent 
marine mammal injury. A final mitigation measure mentioned by 
commenters to the Draft PEA of using vibroseis technology in winter 
instead of open water seismic is not practical due to human safety 
concerns and must be limited to extremely shallow water depths.
    NMFS has several standard, recognized mitigation measures for 
different types of activities. In the case of these Arctic seismic 
IHAs, the Open-water Seismic meeting is the starting point for 
development of new, potentially more effective mitigation measures. 
Suggestions are often both made or dismissed there after an open 
discussion. If specific recommendations were made during the public 
comment that had not previously been vetted or addressed, NMFS would 
address their appropriateness or practicability in this Federal 
Register notice.
    Comment 9: Pursuant to Section 7 of the ESA, NMFS may only 
authorize incidental take of the bowhead whale where such take occurs 
while ``carrying out an otherwise lawful activity''. One commenter 
contends that NMFS is not in compliance with the MMPA or NEPA due to 
some of the issues addressed above and that NMFS is therefore also in 
violation of the ESA.
    Response: For the reasons stated above and throughout the text of 
this notice, NMFS believes we are in compliance with both the MMPA and 
NEPA, and, therefore, the ESA.
    Comment 10: The CBD states that the tables in the proposed IHA 
notice provide no support for NMFS' ``conclusion'' on small numbers and 
negligible impact. For Shell's proposed seismic surveys in the Chukchi, 
the number of bowheads likely to be exposed to sounds of 160 dB or 
greater, and, therefore, ``harassed'' according to NMFS' operative 
thresholds, is 418. In absolute terms these numbers cannot be 
considered ``small.'' Even relative to population size, the higher 
estimate represents 4 percent of the estimated population of bowheads. 
Similar for beluga whales.
    Response: NMFS has made a determination that the takes of the 
affected marine mammal species will be small. The species most likely 
to be harassed during seismic surveys in the Arctic Ocean area is the 
ringed seal, with a modeled maximum estimate of approximately 56,000 
animals being exposed to sound levels of 160 dB or greater. This number 
is approximately 22 percent of the abundance measured in the eastern 
Chukchi Sea, but a much smaller percentage of the entire population. 
The numbers produced by the model do not take into consideration the 
implementation of mitigation measures, the likely avoidance of the 
sound by certain animals and, in the case of ringed seals, the density 
on which the take calculations were based are overestimates (which 
means the take estimates are overestimates) because ringed seals are 
far denser in the inshore and ice areas than in the open ocean where 
the surveys are to occur. Additionally, Moulton and Lawson (2002) 
indicate that most pinnipeds exposed to seismic sounds lower than 170 
dB do not visibly react to that sound; pinnipeds are not likely to 
react to seismic sounds unless they are greater than 170 dB re 1 
microPa (rms)). Further, these estimates are calculated based upon line 
miles of survey effort, animal density and the calculated zone of 
influence (ZOI). While this methodology is valid for seismic surveys 
that transect long distances, those surveys that ``mow the lawn,'' that 
is, remain within a relatively small area, transiting back and forth 
while shooting seismic, numbers tend to be highly inflated. As a 
result, NMFS believes that these exposure estimates are conservative 
and may actually affect far fewer animals.
    The mitigation measures set forth IHA ensure that there will be 
negligible

[[Page 43122]]

impacts on the marine mammals. Cetaceans are expected, at most, to show 
an avoidance response to the seismic pulses. Mitigation measures such 
as visual marine mammal monitoring, and shut-downs when marine mammals 
are detected within the defined ranges should further reduce short-term 
reactions to disturbance, and minimize any effects on hearing 
sensitivity. Due to these mitigation measures, and other reasons 
discussed in the Conclusions of this document, NMFS believes the 
impacts will be negligible.
    Comment 11: Commenters recommended that Conoco be required to cease 
operations at night or in low visibility conditions.
    Response: It is NMFS opinion that once a safety zone is determined 
visually to be free of marine mammals, seismic may continue into 
periods of poor visibility. It should be understood that the safety 
zone is not stationary but is moving along with the ship at whatever 
speed the ship is progressing. For example, if the ship is making 5 
knots, the safety zone will be 5 nm (9.3 km) upstream in an hour. With 
a 180-dB exclusion zone of approximately 1.3 km (0.7 nm), marine 
mammals potentially affected by seismic noise would have ample time to 
move away from the source, as evidenced by bowhead, beluga and gray 
whale avoidance behavior. A review of previous monitoring programs 
indicates these species will not be within a distance to incur Level A 
harassment. For pinnipeds, NMFS believes that because they are not 
likely to even react to seismic sounds unless the received levels are 
>170 dB re 1 microPa (rms), hearing impairment is also unlikely at an 
SPL as low as 190 dB. Therefore, it is unlikely that marine mammals 
will be harmed as a result of continuing seismic into periods of poor 
visibility in Arctic waters. As a result, NMFS has determined that it 
is only if daytime activities have a large abundance of marine mammals 
and/or a significant number of shutdowns, should nighttime seismic be 
prohibited.
    Also as a general rule, termination of seismic during nighttime and 
poor visibility is simply not practicable due to cost considerations 
and ship time schedules. The cost to operate a large seismic vessel is 
approximately $40-50,000 per day. If the vessels were prohibited from 
operating during nighttime, each trip could require several additional 
Arctic survey operations to complete, depending on average daylight at 
the time of work. In the Chukchi and Beaufort seas, fog is common even 
though there is 24 hours of daylight per day until late August, but by 
late September there is less than 12 hours of daylight and by late 
October there would be only 3-4 hours of daylight, seriously limiting 
operations later in the year if a daylight and clear weather 
requirement were imposed.
    Comment 12: One commenter suggested that Conoco should be required 
to lower their source level to reduce impacts to marine mammals.
    Response: In Conoco's application, they requested authorization for 
take of marine mammals incidental to the operation of both a 16-gun 
array and a 24-gun array. After discussions with NMFS they changed 
their action to only include the 16-gun array.
    Comment 13: In submitted comments on the MMS Draft PEA, (and 
referenced by CBD), the NRDC states that harassment of marine mammals 
can occur at levels below the 160 dB threshold for Level B harassment, 
and that NMFS should reassess its harassment thresholds for acoustic 
impacts. To support this recommendation, NRDC reports that harbor 
porpoises have been reported to avoid a broad range of sounds at very 
low SPLs, between 100 and 140 dB.
    Response: As discussed in reference to bowhead whale reactions, 
NMFS does not believe that all types of avoidance rise to the level of 
MMPA harassment.
    The 160-dB rms isopleth is based on work by Malme et al. (1984) for 
migrating gray whales along the California coast. Clark et al. (2000) 
replicating the work by Malme et al. (1984) indicated that this 
response is context dependent, as gray whales did not respond to 
simulated airgun noise when the acoustic source was removed from the 
gray whale migratory corridor. This indicates to NMFS that establishing 
a 160-dB isopleth for estimating a safety zone for low-frequency 
hearing specialists when exposed to a low frequency source is 
conservative. For mid- or high-frequency hearing specialists, a 160-dB 
ZOI for a low-frequency source is likely overly conservative.
    In this action, empirical research indicates that bowhead whales 
respond to sounds at levels lower than 160 dB during periods of 
important biological behavior (migration) but possibly not during other 
important periods (feeding). As a result, to reduce the uncertainty 
over whether these same avoidance characteristics will occur in the 
Chukchi Sea as they appear to have in the Beaufort Sea, MMS and NMFS 
have established conservative ZOIs where additional mitigation measures 
can be imposed to further protect these species during critical periods 
in Arctic waters.
    Comment 14: One commenter states that the preparation of an EIS is 
necessary pursuant to NEPA, especially considering the increased 
controversy that has arisen.
    Response: NMFS has addressed all of the NEPA significance criteria 
in our Finding of No Significant Impact (FONSI), which may be viewed at 
our website. (See ADDRESSES)
    Comment 15: Conoco notes that an important overarching point that 
is not made in the assessment is the health of the marine mammal 
populations in the Arctic, following exposure to over 25 years of 
seismic and other oil and gas activities in the Beaufort and Chukchi 
Seas. The bowhead whale population has increased to near the carrying 
capacity of its habitat (Brandon and Wade 2004). The health of the 
population is reflected further in the high rates of growth and 
reproduction reported in recent years (George et al. 2004a, b). The 
gray whale population has recovered to its pre-exploitation level while 
exposed to far more disturbances throughout its range than marine 
mammals that spend most or all of the year off the coast of Alaska. 
These populations individually and collectively demonstrate their 
resiliency to adapt to their environment and prosper. The healthy 
status of these populations needs to be described by NMFS in their 
assessment of Conoco's application, since it demonstrates that the 
short term and temporary effects of seismic operations on marine mammal 
are biologically insignificant. Moreover, the healthy status of these 
populations is in direct contrast with the speculation about noise 
impacts on the behavior, physiology, reproduction, and communication of 
bowhead whales that is discussed at length by NMFS in their assessment 
of the application. Conoco suggests that NMFS avoid speculation in the 
assessment and focus on using the best available science.
    Response: NMFS acknowledges the health of the bowhead and gray 
whale populations. However, we cannot know whether the increases in 
these populations would have been significantly greater in the absence 
of exposure to over 25 years of seismic and other oil and gas 
activities in the Beaufort and Chukchi Seas, as no data were collected 
that can speak to this issue.
    The healthy condition of the whale populations and the anticipated 
short term and temporary effects of seismic operations were taken into 
account by NMFS in making our MMPA negligible impact determination based on

[[Page 43123]]

Conoco's activities this year in the Chukchi Sea. However, due to our 
responsibilities under NEPA, which include doing an Environmental 
Impact Statement unless we can determine that the activity will have no 
significant impact pursuant to the application of several specific 
criteria (including uncertainty, which exists regarding the 
distribution and specific needs of marine mammals in the Chukchi Sea, 
as described at length in the PEA and FONSIs), NMFS must take a 
precautionary approach in how mitigation is applied in the issuance of 
this IHA.
    Further, the wide-ranging effects of anthropogenic sound, and 
seismic noise in particular, on the behavior, physiology, reproduction, 
and communication of marine mammals is well documented in the 
literature, as referred to in the PEA and the Biological Opinion in 
addition to this document. Though data regarding some of the referenced 
effects of seismic sound on bowhead whales in particular may be 
lacking, NMFS' effects analysis is far from speculative.
    Comment 16: The calculation of the percent of stock represented by 
the estimated take of ringed and bearded seals is not correct. The 
population estimates for these two species are minimum values, since 
the surveys used for the estimates were limited to a relatively small 
portion of their total habitat as discussed in the text of the Federal 
Register. Consequently, the percent of stock values are exaggerated and 
convey a much greater impact on the population than warranted by the 
sizes of the populations. For instance, the actual population estimates 
for ringed seals could be as high as 1 to 3.6 million seals, based on 
earlier studies by Frost and Lowry (1988) and Frost et al. (1988). The 
estimated take based on these values would be 1.5 to 5.6 percent of the 
stock. These values should be substantially adjusted downward to better 
reflect more realistic estimates of population size.
    Response: NMFS notes this overestimation of the percent of stock 
for ringed and bearded seals in Estimate of Take and Conclusions 
sections of this document.
    Comment 17: The calculations of take and safety radii should be 
based on a range and not a single value from the model used by Conoco 
to calculate sound propagation from the air gun array. NMFS used the 
most conservative of the three scenarios run on the Conoco model. Since 
the values are estimates that will be validated in the field, a more 
accurate presentation of take and safety radii would be to use a range 
to represent the uncertainty of the estimated values. For example, the 
range of take for bowhead whales from the three scenarios would be 151 
to 418 animals, which is a more accurate estimate of take than the 418 
value provided by NMFS.
    Response: The calculations of take and safety radii are two separate 
issues. NMFS stands by its use of the most conservative safety radii.
    For the take estimates, Conoco presented the results of three 
propagation models. As suggested above, NMFS has now incorporated the 
estimated take from two of the models into our take table (bowheads 
take is estimated as 399 to 418). However, the third model presented 
safety radii based on Sound Exposure Levels (SELs - an energy metric) 
instead of Sound Pressure Levels (SPLs). NMFS does not have standard 
thresholds for SELs as we have for SPLs (190, 180, and 160) and is not 
prepared to use SEL isopleths as safety radii for this activity. In the 
first-ever issuance of an IHA using SEL levels (for non-explosive 
sounds) as thresholds, which was for mid-frequency tactical sonar (71 
FR 38710, July 7, 2006), NMFS and the Navy worked hard to establish SEL 
thresholds that were specifically applicable to mid-frequency tactical 
signals. NMFS has not yet conducted this level of analysis for seismic 
noise and, therefore, it is not appropriate to use safety radii or 
calculate take based on the modeled SEL results.
    Comment 18: Conoco notes that NMFS expanded the already 
conservative safety radii by adding a correction factor of 1.5 times 
the model values for the 180 and 190 dB shut down distances. The 
correction factor is scientifically unwarranted and should be 
eliminated from the safety radii calculations.
    Response: Because Conoco will be doing the field verification 
first, before beginning any surveys, NMFS has decided that the 1.5 
correction factor is not necessary. This is reflected in the IHA.
    Comment 19: The temporary deflection of migrating bowhead whales 
during the fall around the active seismic vessel discussed by NMFS in 
the Federal Register ignores several key points. Not only are the 
deflections short in distance relative to the migration route and 
temporary, but they occur within the migration corridor. Consequently, 
there is no evidence that the anticipated deflections cause migrating 
bowhead to abandon or move outside the migration corridor or change 
their migratory behavior when encountering an active seismic vessel. 
They simply go around the seismic vessel and continue along the 
migration corridor to the wintering grounds. The temporary nature of 
this behavior is further reflected by the harvest of bowheads during 
the subsistence hunt, which has been very consistent over the last 5-10 
years between 1994 and 2003 where it averaged 40 and ranged from 34 to 
49; weather was largely responsible for annual variation (Suydam and 
George, 2004 and Suydam et al., 2004). In addition, the average number 
of whales landed by village by year is similar between 1974 and 1977 
(before IWC quota) and from 1978 to 2003 (Suydam and George, 2004). 
Consequently, there is no evidence that the deflection around seismic 
operations more than temporarily affects the migration of bowhead 
whales, nor does it affect their availability for subsistence harvest.
    Response: This comment does not acknowledge the fact that more than 
one vessel will be operating seismic in the area at one time, and that 
we do not know exactly how this combination of effects may elicit more 
severe or long term responses by nearby animals. Also, as mentioned 
previously, the capture of any particular number of whales in a given 
year does not mean that a higher number would not have been captured in 
the absence of some disturbance factor. Additionally, the absence of 
evidence regarding effects of these actions on marine mammals does not 
mean we can assume they will not occur. These points and others 
supporting NMFS determinations are presented elsewhere in this document 
and in the PEA.
    Comment 20: There is no scientific basis for establishing a 120-dB 
exclusion zone for bowhead and other marine mammals. The 120-dB 
restrictions are based on misinterpretation of data reported by John 
Richardson (1999), which concludes that deflections of migrating whales 
were not significant to the individual or population of bowhead whales. 
The commenter expresses a similar concern for the 160-dB safety zone.
    Response: The justifications for the 120 dB (and the 160-dB) safety 
radii have been thoroughly discussed in the PEA. Regardless of the 
conclusions Richardson makes, absent an EIS NMFS has to make a 
determination pursuant to NEPA based on several specific criteria, that 
this action is not significant. Due to the scientific uncertainty 
surrounding the potential responses of bowheads to multiple seismic 
vessels in the Chukchi Sea and the lack of knowledge regarding their 
behavioral patterns and needs in

[[Page 43124]]

the Chukchi Sea, NMFS determined that the 120-dB safety zone (and the 
160-dB safety zone) was necessary in order to make a FONSI.
    Comment 21: The 120 dB level is so conservative that it approaches 
and at times may be masked by ambient sound levels, which range from 
68-100 dB in the Chukchi Sea and under certain ice conditions can 
increase to 124-137 dB.
    Response: This information does not change the fact that NMFS 
believes this measure is necessary. Additionally, the measure was 
implemented based on the animal's responses to seismic noise, which is 
different in character from ice noises and may well be discernible even 
in the presence of higher level ice noise.
    Comment 22: Monitoring a 120-dB exclusion zones would be 
impracticable, presents significant and unwarranted safety risks and, 
ultimately, defeats the purpose of the seismic survey program. The 
enormous size of the zone combined with poor weather conditions and the 
remote location of the seismic operations in the Chukchi and Beaufort 
Seas would make monitoring impractical and unnecessarily hazardous.
    Response: NMFS appreciates the need for the safety of the crews 
responsible for monitoring this large area, which is why the IHA only 
requires this additional monitoring weather permitting and when the 
area can be aerially monitored safely.

Comments of AEWC on Specific Pages in Federal Register Notice of 
Proposed IHA

    Comment 23: In the proposed IHA on page 27692, column 1, 1st 
paragraph: The statement attributed to ``Craig George, personal 
communication'' is a misleading misrepresentation of what was actually 
stated. While George did note that ``some whales are being reported off 
Barrow in summer between migrations,'' he in no way stated that 
``subsistence in Barrow should not be affected by seismic operations 
since the location of the hunt is a considerable distance from the 
project area'' -in fact, just the opposite. This statement should be 
retracted and corrected.
    Response: This statement was submitted with the Conoco application 
and NMFS mistakenly inserted it into the FR notice without verifying 
the reference (additionally, the mistaken statement runs counter to 
opinions that Craig George has expressed at past Open-water Seismic 
meetings). NMFS apologizes for the mistake, has removed the inaccurate 
text, and notes the correction here.
    Comment 24: In the proposed IHA on page 27687, Column 2: ``detailed 
description of the Beaufort and Chukchi ecosystems and their associated 
marine mammals'' do not exist, contrary to what is stated here. There 
are many data gaps. Many of the data that do exist are outdated and 
inappropriate for comparison to the current ecosystem dynamics in the 
Chukchi and Beaufort Sea regions, especially in light of current 
climate change concerns.
    Response: NMFS amended the text at this page to reflect that there 
are data gaps, though we do not believe that the data used in this 
notice are inappropriate.
    Comment 25: In the proposed IHA on page 27687, Column 2, 2nd 
paragraph: There are listed only three pinniped species known to occur 
in the study area (ringed, bearded and spotted). Ribbon seals also 
occasionally occur in these areas during the time period of this 
planned seismic operation. In the same paragraph, it is mentioned that 
both minke and killer whales are very uncommon in the area, but NMFS 
does not cite the source of this information. When was the last survey 
of these species during this time period conducted? We are experiencing 
a period of rapid change in the area in question and many species that 
were uncommon 15-20 years ago are being seen more often.
    Response: NMFS amended the text of the Federal Notice notice to 
reflect the occasional occurrence of ribbon seals noted by the 
commenter. NMFS' 2004 stock assessment for killer whales indicates the 
occasional presence of transient killer whales along the northern coast 
of Alaska, but does not include the Chukchi Sea in the distribution 
map. NMFS' 2001 stock assessment indicates that migratory minke whales 
are sometimes seen in the Bering and Chukchi Seas. Though the comment 
questioned the surveys for these species, it does not provide 
information suggesting that these species were more abundant than 
suggested in the proposed IHA Federal Register notice, and local 
biologists at the Open-water peer review meeting did not express 
concerns regarding these species. NMFS still believes that the 
likelihood of encountering, much less harassing, any individuals of 
these species is very low.
    Comment 26: In the proposed IHA on page 27687 Column 3, 3rd 
paragraph: The ratio of density for ringed seals (from which the 
density of bearded seals is deduced) is from work that is over 15 years 
old. It may not be valid to base densities on this information. If the 
abundance estimates are not current, especially in light of 
environmental changes that have been noted in the Chukchi and Beaufort 
Sea regions, it is not scientifically appropriate to use these old 
population estimates for this exercise, even if this is the only data 
available. The population estimates should be based on current data, 
and if none is available, additional population assessments should be 
conducted. This is an example of one of the many data gaps that exist.
    Response: Ringed seal density was based on survey data from 1999 
and 2000. The ratio used to calculate bearded seal data from ringed 
seal data was from was based on data gathered in 1990 and 1991. 
However, actual bearded seal density surveyed in 1999 and 2000 was 5 to 
10 times less than the number used here, but that number was not used 
because the surveyor was unable to correct for missed animals. Though 
NMFS has a responsibility to use the best available science and to be 
precautionary in the absence of data, the MMPA does not mandate that 
NMFS deny authorizations until data are available.
    Comment 27: In the proposed IHA on page 27687, Chart: The estimated 
take of 10.7-22.7 percent of the ringed seals in the area without 
mitigation seems like a very high number of animals to take. 
Additionally, the estimates for gray whales should probably be revised, 
depending on when the data were collected. From recent tagged gray 
whale data and hunter observations, increasing numbers of gray whales 
are remaining in the Bering/Chukchi region for extended periods of time 
than previously thought. (B. Mate, personal communication). These data 
should include a seasonality dimension as a fine tuning method, as many 
of these species are more likely to be present in certain areas at 
certain times of the year.
    Response: The take estimate for ringed seals, and other animals, 
does not take into account either the effectiveness of the required 
mitigation or the fact that most animals are expected to move to avoid 
the seismic sounds. Additionally, these animals are not removed from 
the populations, nor does their response to Level B harassment far 
offshore in the Chukchi Sea necessarily affect their behavior at all 
inshore where they are hunted. The abundance and density data used for 
calculating gray whales were gathered in 2002. When available, NMFS 
incorporates seasonally specific abundance information into the 
calculation of take.
    Comment 28: In the proposed IHA on page 27687, Column 3, point 4, 
below chart: The chronic effects of noise exposure and the fact that we 
know very

[[Page 43125]]

little about this in marine mammals should be included in these points.
    Response: Point 6 mentions that chronic exposure to noise could 
result in noise-induced physiological stress that might in turn have 
negative effects on the well-being or reproduction of the animals involved.
    Comment 29: In the proposed IHA on page 27688, Column 1, point 7: 
It is not valid to compare seismic effects in terrestrial mammals with 
those in marine mammals. The sound is perceived in a totally different 
environment by species that have evolved to receive auditory sounds in 
a completely different way.
    Response: Statements in the paragraph this commenter refers to were 
actually verified in laboratory TTS research conducted on trained 
odontocetes so it is not necessary to rely on an extrapolation from 
terrestrial mammal data. However, NMFS notes that while it may not be 
appropriate to use terrestrial mammal data to extrapolate to actual 
levels of different types of sound that may affect marine mammals, the 
physical construction of the ears bears enough resemblance that experts 
in the field deem that it is sometimes appropriate to compare processes 
between the two taxa.
    Comment 30: In the proposed IHA on page 27688, Column 1, point 6: 
In addition to the well being and reproduction, the feeding and 
migration behaviors of these animals may be affected.
    Response: NMFS has acknowledged elsewhere in this FR notice that 
noise may affect the feeding and migration behaviors of marine mammals. 
This point specifically refers to potential chronic effects and larger-
scale effects such as a reduction in fitness or reproductive success.
    Comment 31: In the proposed IHA on page 27688, Column 1, paragraph 
4: The seismic geological survey work that will also be conducted 
during the time period (University of Texas Austin (UTA) Institute of 
Geology) should be added to the list of seismic surveys.
    Response: The UTA program is a separate action that is currently 
under internal NMFS review following a public comment period (see 71 FR 
27997, May 15, 2006). Essentially, that program is significantly 
farther north in the Chukchi Sea than are the oil company surveys, is 
for a shorter period of time during the summer, will have completed its 
work prior to the bowhead migration, and establishes very conservative 
safety zones to protect marine mammals. A final decision on 
implementation of mitigation measures will be made later this month
    Comment 32: In the proposed IHA on page 27688, Column 2, paragraph 
2: With respect to masking: some bowhead whales stop calling altogether 
(C. Clark, pers. comm.), and only one study has found that bowheads 
continue to call in the present of seismic activity. This needs to be 
considered as a possible outcome of seismic disturbance.
    Response: NMFS acknowledges the fact that a possible outcome of 
seismic disturbance is that some cetaceans will sometimes stop calling 
and, in fact, this reaction has been documented in other species 
besides bowheads.
    Comment 33: In the proposed IHA on page 27688, column 2, 2nd 
paragraph: The absence of masking effects in beluga whales cannot be 
assumed secondary to the fact that they communicate on higher 
frequencies. There are no data available on this subject. These noises 
will most certainly be audible to this species and there is no peer 
reviewed evidence investigating the impacts of these sounds on beluga 
whales. Until these investigations are conducted, these conclusions 
should not be made. It appears here that the lower sensitivity of 
belugas to seismic pulses is ``presumed''.
    Response: The hearing thresholds of belugas have been tested in a 
laboratory and we know that belugas demonstrate significantly greater 
sensitivity to sounds of greater frequency than those used in seismic 
surveys (meaning they hear it at a lower volume). NMFS is not asserting 
that belugas will not hear the seismic sounds, only that the lower 
frequency seismic sounds will not mask (meaning block out) the higher 
frequency sounds that are known to be important to them, such as the 
vocalizations of conspecifics or predators.
    Comment 34: In the proposed IHA on page 27688, column 2, 2nd 
paragraph: It is true that there is no evidence that there has been 
damage to auditory systems in bowhead whales, however, there have been 
no investigations that have focused on this issue. There are no data. 
This lack of data does not mean this damage does not occur.
    Response: This is true. However, based on the limited data, the 
known avoidance of the sound sources by bowheads, and the protective 
measures incorporated in this IHA, NMFS does not expect any hearing 
damage to result from this seismic survey.
    Comment 35: In the proposed IHA on page 27688, column 2, 3rd 
paragraph: ``Moreover, bowheads avoid an area many kilometers in radius 
around ongoing seismic operations, precluding any possibility of 
hearing damage.'' This statement is not valid.
    Response: NMFS amended the text and removed the words ``precluding 
any possibility'' and replaced it with ``making hearing damage highly 
unlikely''.
    Comment 36: In the proposed IHA on page 27688, column 2, 3rd 
paragraph: If bowheads or other marine mammals are involved in feeding 
or other vitally important functions, they may not move away from 
seismic operations, potentially resulting in physical harm.
    Response: This is true; however, NMFS anticipates that bowheads 
involved in feeding will be detected by the additional protective 
measures required in the IHA and that the extended shut-down zones will 
minimize effects on any marine mammals engaged in these activities.
    Comment 37: In the proposed IHA on page 27688, Column 3, 1st 
paragraph: We wish to emphasize, once again, that there has been very 
little study on the chronic effects of seismic disturbance on marine 
mammals. This includes disruption of cow/calf pairs (leading to 
increased neonatal mortality) and displacement of whales (and other 
marine mammals) from migratory routes or preferred feeding areas 
(possibly resulting in suboptimal body condition).
    Response: NMFS acknowledges that there has been little study of 
these specific effects , and that is why we have not specifically 
addressed these issues in this FR Notice. However, NMFS has included of 
a summary of potential physiological effects, including stress.
    Comment 38: In the proposed IHA on page 27689, center column: NMFS 
cites Miller et al., (1999) to assert that when the issue of bowhead 
deflection due to seismic activity was studied, though very few 
bowheads approached a seismic operation within 20 km (6.5 mi), the few 
bowheads sighted within that area ``returned to normal'' within 12 to 
24 hours after airgun operations ended. This paragraph refers to 
observations made by Miller et al., in Richardson et al. (1999). The 
study suggested that bowheads reoccupy a previously active seismic area 
within 12 to 24 hours of cessation of seismic activity. This paragraph 
overstates the conclusions in Richardson et al. (1999). First, 
Richardson et al. stated that their analysis of reoccupation was 
preliminary but MMS does not treat it as such in the PEA. Secondly, the 
number of observations within a 20 km (6.5 mi) zone around the 
previously active seismic activity was small (only 13 whales were 
observed between zero and 96 hours after seismic activity). This small 
sample size means that the statistical power (i.e. ability) to detect a

[[Page 43126]]

difference is low. Second, the data could reasonably be interpreted in 
other ways, such as: (1) the overall results (over the entire survey 
period, 0 to 96 hours after seismic activity, the density of whales in 
the 0 to 20 km zone was lower than the density in the 20 to 80 km (6.5 
to 26 mi) zone, p< 0.001 indicated that whales did not reoccupy the 
active seismic zone even after 96 hours, but there were no data 
collected beyond 96 hours, so the reoccupation might have taken longer 
than 96 hours; or (2) the whales immediately reoccupied the active zone 
because the multiple comparison tests (binomial tests) did not show a 
difference in density of whales between the zones in the category of 1 
to 12 hours after seismic. These two wildly different interpretations 
provide evidence that the analysis was preliminary and the sample size 
too small to adequately test the question of reoccupation.
    Response: NMFS acknowledges the commenter's alternate 
interpretation of the Miller study. NMFS presented this study as one of 
several pieces of information that relate to this topic. Though the 
commenter has presented alternate interpretations, the information is 
not such that it will affect NMFS' findings.
    Comment 39: In the proposed IHA on page 27690, column 2, 2nd 
paragraph: NMFS recommends the 160-dB isopleth as the level to estimate 
the numbers of marine mammals taken by level B harassment. This level 
is inappropriate. Data exist to show that bowheads are essentially 
excluded from areas with seismic sounds to levels below 120 dB 
(Richardson et al., 1999). The 120 dB level is the appropriate level to 
use. If bowheads or other marine mammals are involved in feeding or 
other vitally important functions, they may not move away from seismic 
operations potentially resulting in physical harm.
    Response: Bowhead whales have been shown to avoid areas ensonified 
to above 120 dB. Though this deflection could potentially affect the 
success of the subsistence hunt of this species, NMFS does not believe 
that this effect rises to the level of MMPA harassment. Based on the 
work of Malme et al., NMFS believes that 160 dB is the appropriate 
threshold for Level B Harassment. NMFS does not believe that seismic 
surveys will result in physical harm to whales at levels lower than 180 
dB and the mitigation measures require that Conoco cease operating 
seismic if an animal approaches this close. Additionally, this IHA 
includes additional mitigation measures that require a powerdown (or 
avoidance) when aggregations of feeding mysticetes are found within the 
160-dB isopleth.
    Comment 40: In the proposed IHA on page 27690, column 3, 1st 
paragraph: These sound level output radii are highly dependent on the 
environment. The uncertainty of these figures should be noted. Factors 
(such as ice cover or permafrost) may alter these radii significantly. 
Why will the 1.5 factor not be used in take estimations?
    Response: NMFS has noted previously that sound level output radii 
are dependent on the environment, which is why this IHA requires that 
Conoco field-verify the radii prior to conducting the surveys. For the 
take estimates, Conoco contracted with Jasco, which ran a model that 
incorporates the physical characteristics of the area where seismic 
surveys will be conducted. NMFS believes that this is an appropriate 
model to use to estimate take (and, as discussed later in this 
document, the model probably overestimates take as the estimates do not 
consider avoidance and mitigation). The 1.5 safety radii correction 
factor is an extra protective measure NMFS added only to be used prior 
to the field-verification. We do not believe it is appropriate to 
adjust the take estimates based on this precaution.
    Comment 41: In the proposed IHA on page 27690, column 3, 1st 
paragraph: Will the M/V Patriot be towing a passive array for 
additional acoustic data collection? We strongly support the use of a 
towed passive acoustic array for monitoring marine mammals. Conducting 
aerial surveys in conjunction with the passive acoustic monitoring 
would be more appropriate and effective than either technique alone. 
Use of acoustic monitoring should routinely be required for seismic 
exploration in these areas and can only add to the information being 
gathered about marine mammals.Response: The mitigation and monitoring 
required by this IHA, which includes both an aerial component and a 
passive acoustic component, is discussed in detail in subsequent 
sections of this notice.
    Comment 42: In the proposed IHA on page 27691, first column: the 
estimate of take by harassment is calculated by multiplying the 
estimated densities per km\2\ of bowhead whales within the proposed 
survey area by the width of the 160 dB safety radii (4,590 m (15059 
ft)) over the length of Conoco's estimated trackline. However, it is 
unclear how the estimated densities are calculated. This is important 
because the estimated take is very sensitive to the estimated density 
used in the formula. Also, there is no information provided on the time 
period for which the estimated density figure was measured, nor during 
which season. These two factors are highly variable and would greatly 
influence the estimated density figure. Finally, it is important to 
note that if the migration path is concentrated in the seismic 
exploration area, then the number of takes could be an order of 
magnitude higher than .0064 per km2. This is significant because NMFS 
has predicated its preliminary decision to authorize the harassment on 
its conclusion that ``the number of potential harassment takings is 
estimated to be relatively small in light of the population size.'' See 
page 27695 of the proposed IHA.
    Response: The density estimates for bowhead whales are based on 
Moore et al. (2000), who reported the densities of belugas, bowheads, 
and gray whales during summer in the Beaufort and Chukchi Seas. 
Additionally, even if the seismic activities are in the middle of the 
migration, NMFS believes many whales will avoid the sound source (which 
equates to avoiding take for some animals), and the successful 
implementation of the mitigation measures will also decrease the amount 
of take.
    Comment 43: In the proposed IHA on page 27691, column 1, 1st 
paragraph: There is no way of knowing that only level B harassment will 
occur, especially in pinnipeds. The lack of data on this subject 
precludes making this conclusion.
    Response: There is no way of absolutely ensuring that Level A 
Harassment will not occur as a result of this action, however, for the 
reasons stated in the above-referenced section and throughout the FR 
notice (mitigation, avoidance of whales, etc.) NMFS believes that it is 
very unlikely that Level A Harassment will result and, therefore, NMFS 
is not authorizing Level A Harassment. If any take of marine mammals 
that is not authorized occurs, Conoco is required to alert NMFS within 
24 hours and the authorization may be modified, suspended, or revoked.
    Comment 44: In the proposed IHA on page 27691, column 3, 1st 
paragraph: Please produce a citation for your statement that 
``zooplankton consumed by mysticetes would only respond to a seismic 
impulse very close to the source.'' Recent work in invertebrates has 
shown that this may not be the case, and it is not only prey number 
that is a concern, but also prey distribution. Impacts from seismic on 
the distribution of prey species have been found. If (for example) 
krill distribution is affected, distributing them in a different area of

[[Page 43127]]

the water column or breaking up their distribution (thereby making them 
a less concentrated resource), bowheads are likely to be impacted. This 
is yet another example of the data gap related to the proposed seismic 
exploration.
    Response: NMFS could not find the citation and has removed the 
sentence from the text. However, the commenter did not provide a 
citation for the information it presented above, either, and therefore, 
no specific viewpoint regarding the potential effects of seismic on 
zooplankton is presented.
    Comment 45: In the proposed IHA on page 27691: Potential Effects on 
Subsistence Use of Marine Mammals. There is a statement that Point Hope 
and Wainwright hunt only during the spring migration. In fact, Point 
Hope and Wainwright plan to undertake fall whaling beginning in 2006 
due to changes in Arctic weather and sea ice conditions.
    Response: NMFS has corrected the text per the AEWC's suggestion.
    Comment 46: In the proposed IHA on page 27692, column 1, 2nd 
paragraph: It is important to note that even if direct conflicts with 
hunting times are avoided, bowheads may still be impacted in ways that 
will adversely affect the hunt. Examples of this include (but are not 
limited to): disruption of cow/calf pairs (leading to increased 
neonatal mortality) and displacement of whales (and other marine 
mammals) from migratory routes or preferred feeding areas (possibly 
resulting in suboptimal body condition).
    Response: NMFS notes the lack of direct evidence to support the 
thought that seismic surveys will result in effects on subsistence 
hunting through the mechanisms discussed above. However, because of the 
uncertainty surrounding the issue, NMFS has incorporated additional 
mitigation (including enlarged safety zones, see below) to address the 
AEWC's concerns.
    Comment 47: In the proposed IHA on page 27693, column 2, bullet 3: 
Bowhead whales are known to hold their breath for 45-60 minutes at a 
time (H. Brower, pers. comm.). Thus, 30 minutes is not a sufficient 
waiting time with respect to this species.
    Response: Seismic vessels are moving continuously (because of long 
towed array) and NMFS believes that unless the animal submerges and 
follows at the speed of the vessel (highly unlikely), the vessel will 
be far beyond the length of the safety radii within 30 minutes, and 
therefore it will be safe to start the airguns again.
    Comment 48: In the proposed IHA on page 27693, column 3, 2nd 
paragraph: Night vision goggle devices have proven ineffective for 
nighttime monitoring of marine mammals in other instances. It is 
unlikely that these will be of use in visualizing the entire exclusion 
zone, especially if it is not set at the180 dB isopleth.
    Response: NMFS is aware that night vision goggles are not 100 
percent effective. However, the airguns will be ramped up, the animals 
are likely to avoid the ongoing sound, and the goggles are effective to 
a certain degree. NMFS believes that Conoco will be able to effectively 
monitor out to the 180 dB isopleth.
    Comment 49: In the proposed IHA on page 27695, column 2, paragraph 
1: The statement `` no known rookeries, mating grounds, areas of 
concentrated feeding or other areas of special significance for marine 
mammals are known to occur within or near the planned areas of 
operations `` is incorrect. The western Beaufort Sea supports 
concentrations of feeding bowhead whales. Also, the Chukchi Sea area 
represents a ``black box'' with respect to data on marine mammal usage 
in general, and for bowhead whales in particular, but several sensitive 
life stages occur there for bowheads, belugas, ice seals and walrus for 
calving, nursing, mating and feeding. For instance, bowhead mother-calf 
pairs occur there in spring, as well as the feeding of adults and sub-
adults.
    Response: NMFS has amended this statement to indicate that an 
important migration pathway is present here. Though mother/calf pairs 
of bowheads swim through the area and other species do feed in 
aggregations in the broad area, NMFS stands by its assertion that ``no 
known rookeries, mating grounds, areas of concentrated feeding, or 
other areas of special significance for marine mammals are known to 
occur within or near the planned areas of operations during the season 
of operations.
    Comment 50: In the proposed IHA on page 27695: Potential Impacts on 
Subsistence Uses of Marine Mammals. NMFS predicates its preliminary 
decision that the proposed seismic activity will not have an 
unmitigable adverse impact on the subsistence uses of bowhead whales on 
the timing of the activities, as well as the existence of a CAA between 
Conoco and the AEWC. We urge NMFS to use caution in relying too heavily 
on the CAA as a mitigation tool when the proposed activity involves 
several concurrent operations in what could be a concentrated area of 
the Arctic. Without knowledge of either where the individual seismic 
vessels will be located and in consideration of how little is actually 
known of bowhead distribution and abundance in the Chukchi Sea, the CAA 
is in fact limited as a mitigation tool. It can only accomplish so much 
to protect the fall hunt in Barrow because the success of that hunt 
will depend not only on the effects of multiple seismic operations in 
the Chukchi Sea, but also potentially adverse effects from Shell's 
Beaufort Sea seismic operations, seismic operations in the Canadian 
Beaufort Sea, barging operations attendant to oil and gas development, 
and production operations at the Northstar facility.
    Response: While sympathetic to the concern of increasing 
industrialization of the Arctic Ocean and resultant impacts on the 
subsistence lifestyle of its inhabitants, section 101(a)(5)(D)(i) 
limits NMFS' authority for making its determination regarding impacts 
on availability of marine mammals for subsistence uses to the specific 
activity itself. As a result, NMFS works cooperatively with the AEWC to 
ensure that activities that might result in marine mammal harassment 
and have a potential impact on availability for subsistence uses have 
an authorization under the MMPA and that the applicant enters into 
discussions with the AEWC regarding a CAA. However, under NEPA, NMFS 
and MMS are required to look at cumulative effects and, as a result of 
this analysis we have incorporated additional mitigation measures 
(research monitoring, expanded safety zones, etc., see below) to 
address these larger scale concerns.

Mitigation and Monitoring

    Three categories of mitigation and monitoring measures are required 
by the IHA and discussed in the following sections. In the first 
subsection, the mitigation and monitoring measures proposed by Conoco 
in their application are discussed. In the second subsection, NMFS 
discusses an additional set of mitigation measures that are intended to 
ensure that NMFS' can adopt MMS' PEA and subsequently issue a Finding 
of No Significant Impact. The third subsection refers to an additional 
comprehensive monitoring plan that Conoco, Shell, and GXT have agreed 
to implement, which is intended to further reduce impacts to the 
subsistence hunt and help fill some of the marine mammal data gaps in 
the Chukchi Sea.

Mitigation and Monitoring Measures in Conoco's Application

Mitigation
    Conoco's proposed mitigation measures include (1) speed or course 
alteration, provided that doing so will not compromise operational 
safety requirements, (2) power-or shutdown procedures for the 180-dB 
safety zone,

[[Page 43128]]

(3) no start up of airgun operations unless the full 180-dB safety zone 
is visible for at least 30 minutes during day or night, (4) ramp-up 
procedures, and (5) seasonal restrictions near certain whaling villages 
and communication with whalers to ensure minimization of effects on 
subsistence hunt pursuant to the CAA. Details regarding these measures 
are provided below:
    Speed or Course Alteration: If a marine mammal is detected outside 
the safety radius and, based on its position and the relative motion, 
is likely to enter the safety radius, the vessel's speed and/or direct 
course may, when practical and safe, be changed in a way that avoids 
the marine mammal and also minimizes the effect on the seismic program. 
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 power down or shut down of 
the airgun(s).
    Power-down Procedures: A power down involves decreasing the number 
of airguns in use such that the radius of the 180-dB (or 190-dB) zone 
is decreased to the extent that marine mammals are not in the safety 
zone. A power down may also occur when the vessel is moving from one 
seismic line to another. During a power down, one airgun is operated. 
The continued operation of one airgun is intended to alert marine 
mammals to the presence of the seismic vessel in the area. In contrast, 
a shut down occurs when all airgun activity is suspended. If a marine 
mammal is detected outside the safety radius but is likely to enter the 
safety radius, and if the vessel's speed and/or course cannot be 
changed to avoid having the mammal enter the safety radius, the airguns 
may (as an alternative to a complete shut down) be powered down before 
the mammal is within the safety radius. Likewise, if a mammal is 
already within the safety zone when first detected, the airguns will be 
powered down if doing so leaves the animals outside of the new safety 
radii around the airguns still operating, else they will be shut down. 
Following a power down, airgun activity will not resume until the 
marine mammal has cleared the safety zone. The animal will be 
considered to have cleared the safety zone if it:
    ? Is visually observed by marine mammal observers (MMOs) to 
have left the safety zone, or
    ? Has not been seen within the zone for 15 min in the case 
of pinnipeds or belugas, or
    ? Has not been seen within the zone for 30 min in the case 
of bowhead, gray, or killer whales.
    Shut-down Procedures: The operating airgun(s) will be shut down 
completely if a marine mammal approaches or enters the safety radius 
and a power down will not succeed in removing the animal from within 
the 180 dB isopleth. The operating airgun(s) will also be shut down 
completely if a marine mammal approaches or enters the estimated safety 
radius of the source that would be used during a power down. The 
shutdown procedure should be accomplished within several seconds (of a 
``one shot'' period) of the determination that a marine mammal is 
within or about to enter the safety zone. Airgun activity will not 
resume until the marine mammal has cleared the safety radius. The 
animal will be considered to have cleared the safety radius if it is 
visually observed to have left the safety radius, or if it has not been 
seen within the radius for 15 minutes (beluga and seals) or 30 minutes 
(bowhead, gray, and killer whales).
    Ramp-up Procedures: A ``ramp up'' procedure will be followed when 
the airgun array begins operating after a specified-duration period 
without airgun operations. Under normal operation conditions (4-5 knots 
(7.4-9.2 km/hr)) a ramp-up would be required after a ``no shooting'' 
period lasting 2 minutes or longer. NMFS normally requires that the 
rate of ramp up be no more than 6 dB per 5 minute period. The specified 
period depends on the speed of the source vessel and the size of the 
airgun array that is being used. Ramp up will begin with the smallest 
gun in the array that is being used for all subsets of the array. Guns 
will be added in a sequence such that the source level in the array 
will increase at a rate no greater than 6 dB per 5-minutes, which is 
the normal rate of ramp up for larger airgun arrays. During the ramp up 
(i.e., when only one airgun is operating), the safety zone for the full 
16-airgun system will be maintained.
    If the complete safety radius has not been visible for at least 30 
minutes prior to the start of operations in daylight or nighttime, 
ramp-up will not commence unless one gun has been operating during the 
interruption of seismic survey operations. This means that it will not 
be permissible to ramp up the source from a complete shut down in thick 
fog or at other times when the full safety zone is not visible (i.e., 
sometimes at night). If the entire safety radius is visible using 
vessel lights and/or Night Vision Devices (NVDs) (as may be possible 
under moonlit and calm conditions), then start up of the airguns from a 
shut down may occur at night. If one airgun has operated during a 
power-down period, ramp up to full power will be permissible at night 
or in poor visibility, on the assumption that marine mammals will be 
alerted to the approaching seismic vessel by the sounds from the single 
airgun and could move away if they choose. Ramp-up of the airguns will 
not be initiated if a marine mammal is sighted within or near the 
applicable safety radii during the day or a night. For operations in 
the Chukchi during summer and autumn months, there will be enough 
daylight to monitor beyond a 12-hour cycle.
    Seasonal Restrictions: Once fall bowhead whaling starts, seismic 
operators (and others) will take all reasonable steps to avoid adverse 
effects on the bowhead whale subsistence hunt and on the behavior of 
migrating bowhead whales. If alerted to an adverse effect, the 
operators will promptly reduce the level and volume of geophysical 
operations and if such adverse effects continue, operators should 
promptly move operations to an area where seismic operations are 
feasible and consistent with the CAA. If adverse effects continue and 
negotiations are unsuccessful, the seismic operations are to cease in 
the area of the reported adverse effect until the affected village has 
completed its bowhead whale hunting for 2006.
    If requested, post-season meetings will also be held to assess the 
effectiveness of the 2006 CAA, to address how well conflicts (if any) 
were resolved; and to receive recommendations on any changes (if any) 
might be needed in the implementation of future CAAs.
Monitoring
    Vessel-based observers will monitor marine mammals near the seismic 
vessel during: (1) all daytime hours; (2) 30 minutes before all start 
ups (day or night), and (3) at night when marine mammals are suspected 
(based on observations of the bridge crew) of either approaching or 
being within the safety radii. When feasible, observations will also be 
made during daytime periods during transits and other operations when 
guns are inactive.
    During seismic operations observers will be based aboard the 
vessel. Marine mammal observers (MMOs) will be hired by Conoco, with 
NMFS approval. One resident from the NSB, preferably from Point Hope, Point 
Lay, Wainwright, or Barrow, who is knowledgeable about marine mammals

[[Page 43129]]

of the project area will be included in the MMO team aboard the vessel. 
Observers will follow a schedule so at least two observers will 
simultaneously monitor marine mammals near the seismic vessel during 
ongoing daytime operations and nighttime start ups of the airgun. Use 
of two simultaneous observers will increase the proportion of the 
animals present detected near the source vessel. MMO(s) will normally 
be on duty in shifts no longer than 4 hours. The vessel crew will also 
be instructed to assist in detecting marine mammals and implementing 
mitigation requirements (if practical). Before the start of the seismic 
survey the crew will be given additional instruction on how to do so.
    The vessel is a suitable platform for marine mammal observations. 
When stationed on the flying bridge, the eye level will be 
approximately 10 m (32.8 ft) above sea level, and the observer will 
have an unobstructed view around the entire vessel. If surveying from 
the bridge, the observer's eye level will be about 10 m (32.8 ft) above 
sea level and approx. 25 of the view will be partially obstructed 
directly to the stern by the stack. During daytime, the MMO(s) will 
scan the area around the vessel systematically with reticle binoculars 
(e.g., 7 50 Bushnell or equivalent) and with the naked eye. Laser range 
finders (Leica LRF 1200 laser rangefinder or equivalent) will be 
available to assist with distance estimation. They are useful in 
training observers to estimate distances visually, but are generally 
not useful in measuring distances to animals directly. During darkness, 
NVDs will be available (ITT F500 Series Generation 3 binocular-image 
intensifier or equivalent), if and when required.
    MMOs will collect the following data during their watch:
    (1) Marine mammals - species, number, age/size/gender, behavior, 
movement, distance and bearing from ship, point of closest approach;
    (2) Ship - location, heading, speed, seismic state, time, other 
ships; and
    (3) Environment - sea state, ice cover, visibility, glare.
    All observations and airgun shut downs will be recorded in a 
standardized format. Data will be entered into a custom database using 
a notebook computer. The accuracy of the data entry will be verified by 
computerized validity data checks as the data are entered and by 
subsequent manual checking of the database. These procedures will allow 
initial summaries of data to be prepared during and shortly after the 
field program, and will facilitate transfer of the data to statistical, 
graphical, or other programs for further processing and archiving.
    Results from the vessel-based observations will provide:
    (1) The basis for real-time mitigation (airgun shut-down and 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.
    (5) Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

Additional Mitigation and Monitoring Measures Required by NMFS

    Chase Boat Monitoring of 160-dB Isopleth
    In addition to MMOs onboard the seismic vessels, Conoco will also 
have MMOs onboard a ``chase boat'' or ``guard boat''. During seismic 
operations, a chase boat remains very near to the stern of the source 
vessel anytime a member of the source vessel crew is on the back deck 
deploying or retrieving equipment related to the seismic array. Once 
the seismic array is deployed the chase boat then serves to keep other 
vessels away from the seismic vessel and its array (including the 
hydrophone streamer) during production of seismic data and provide 
additional emergency response capabilities. Whenever source vessel 
members are not working on the back deck and radar indicates no vessels 
approaching the source vessel, the chase boat will conduct observations 
of the area delineated by the 160-dB isopleth to look for bowhead and 
gray whale aggregations.
    Conoco's chase boat will have MMOs onboard to collect marine mammal 
observations. The observations collected will likely be limited in 
scope due to the typical operating location of the chase boats 
(described previously). However, the observers aboard the chase boat 
will provide additional observations on the water to document any 
marine mammals in the vicinity of seismic operations. MMOs on the chase 
boat will be able to contact the seismic vessel if marine mammals are 
sited. To maximize the amount of time during the day that an observer 
is on duty, observers aboard the chase boat will rarely work at the 
same time. As on the source vessel, shifts will be limited to 4 hours 
in length and 12 hours total in a 24-hour period.
Aerial Monitoring of 120-dB Isopleth
    Based on the PEA, NMFS has determined that in order to make a 
Finding of No Significant Impact under NEPA regulations, Conoco must 
conduct aerial monitoring in the Chukchi Sea after September 25, once 
research vessel monitoring has detected 5 or more cow/calf pairs during 
a vessel transit (see Research Monitoring) or once bowhead whale 
hunters have determined that cow/calf pairs are passing Barrow AK in 
significant numbers (a ``pulse'' of cow/calf pairs, verified by the 
AEWC), whichever is sooner. Once initiated, aerial monitoring will take 
place daily (weather permitting), whenever Conoco's seismic vessel is 
conducting seismic surveys and is operating within an area of the 
Chukchi Sea that can be covered safely and practically. The primary 
objectives of the offshore aerial surveys will be to (1) document the 
occurrence, distribution, and movements of bowhead and gray whales, and 
other marine mammals in and near the area where they might be affected 
by the seismic sounds and (2) detect bowhead whale cow/calf pairs in or 
near the area ensonified to a 120-dB SPL near the seismic survey vessel.
Mitigation Associated With 120- and 160-dB Safety Radii
    NMFS notes that the additional mitigation measures described here 
are project-specific. They do not establish NMFS policy applicable to 
other projects or other locations. These mitigation measures apply 
exclusively to the Chukchi and Beaufort seas and seismic survey 
activities conducted there during the 2006 open water season. These 
measures have been developed based upon available data specific to the 
project areas and times. NMFS and MMS intend to gather and receive 
additional information from all sources, including industry, non-
governmental organizations, Alaska Natives and other federal and state 
agencies. MMS and NMFS anticipate that mitigation measures applicable 
to future seismic and other activities will change and evolve based on 
newly-acquired data.
    160-dB Feeding Aggregation Shutdown: Whenever the support ``chase'' 
vessel monitoring program described in the monitoring section above 
detects an aggregation of 12 or more non-migratory balaenopterid whales 
(bowhead or gray whales) within an acoustically verified 160-dB rms 
zone ahead of, or perpendicular to, the

[[Page 43130]]

seismic vessel track, Conoco must: (a) Immediately power-down the 
seismic airgun array and/or other acoustic sources to ensure that sound 
pressure levels at the shortest distance to the aggregation do not 
exceed 160 dB rms; and (b) Refrain from powering up the seismic airgun 
array until biological observers on board the support ``chase'' 
vessel(s) or survey aircraft confirm that no balaenopterid aggregations 
have been detected within the 160-dB zone based upon ship course, direction 
and distance from last sighting and the last aggregation sighting.
    120-dB Bowhead Cow/Calf Shutdown: Whenever the aerial monitoring 
program described in the Monitoring section above detects 4 or more 
bowhead whale cow/calf pairs within an acoustically-verified 120-dB 
monitoring zone, Conoco must: (a) Immediately power-down or shut-down 
the seismic airgun array and/or other acoustic sources to ensure that 
sound pressure levels are reduced by at least 50 percent; and (b) 
Refrain from ramping up the seismic airgun array until two consecutive 
aerial or support vessel surveys confirm that there are no more than 3 
bowhead cow/calf pairs within the area to be seismically surveyed 
within the next 24 hours.
    Passive Acoustic Optional 120-dB Shutdown: If an aerial monitoring 
program cannot be implemented due to human safety concerns, and vessel 
surveys are used to monitor the 120-dB monitoring zone instead, a 
dedicated passive acoustic monitoring program capable of locating the 
position of the vocalization must be employed and monitored at all 
times that seismic is operating on the vessel. If the passive acoustic 
system detects one or more bowhead vocalizations within the 120-dB 
zone, the holder of this Authorization must: (a) Immediately shut-down 
the seismic airgun array and/or other acoustic sources; and (b) not 
proceed with ramping up the seismic airgun array until the passive 
acoustic monitoring program confirms that bowhead whales are not within 
the eastern portion of the 120-dB zone ahead of the ship's trackline 
over the next 24 hours.

Additional Comprehensive Monitoring Plan

    On April 19-20, 2006, NMFS held a scientific open-water seismic 
meeting in Anchorage, AK to discuss appropriate mitigation and 
monitoring measures for Arctic Ocean seismic activities in 2006. The 
workshop participants recommended several monitoring measures to 
increase our knowledge of marine mammal distribution and abundance in 
the Chukchi Sea. These included use of passive acoustics, either towed 
from a vessel or set out in a series of arrays along the Chukchi Sea 
coast. Conoco has agreed to participate in a joint monitoring plan with 
Shell and GXT, the two other companies conducting surveys semi-
concurrently with Conoco. The details of the plan have been reviewed by 
NMFS staff, NSB biologists, and representatives of the AEWC. The major 
components of the plan are summarized below, however, some of the finer 
details of the plan are still being discussed and may still be 
modified. The Comprehensive Monitoring Plan may be viewed at: 
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.

Aerial Surveys
    Shell, CPA and GXT will conduct a joint aerial survey of coastal 
areas approximately 20 miles offshore between Point Hope and Point 
Barrow to collect data and report on the distribution, numbers, 
orientation and behavior of marine mammals, particularly beluga whales, 
near traditional hunting areas in the eastern Chukchi Sea. This aerial 
survey will begin in early July and will continue until mid-November or 
until all seismic operations in the Chukchi Sea are completed, 
whichever comes first. Weather and equipment permitting, aerial surveys 
will be conducted twice per week during this time period. Transects 
will be flown in a saw-toothed pattern extending from Point Barrow to 
Point Hope. This design will permit completion of the survey in one day 
and will provide representative coverage of the nearshore area from the 
mainland or outer barrier island shore to 20 nm (37 km) offshore. This 
includes waters where belugas would be available to subsistence 
hunters. Survey altitude will be at least 305 m (1000 ft) with an 
average survey speed of 100-120 knots (185-222 km/hr). Coordination 
will be undertaken with coastal villages to avoid disturbance of the 
beluga whale subsistence hunt. Three MMOs will be aboard the aircraft 
during key beluga hunting periods. When large concentrations of belugas 
are encountered during the saw-toothed pattern surveys or during return 
(direct) flights, the survey will be interrupted to photograph the 
groups in order to obtain counts of the number of belugas present. 
Detailed information on this survey can be found in LGL (2006).
Dedicated Vessel-Based Marine Mammal Surveys
    Shell, CPA and GXT will sponsor a dedicated vessel-based marine 
mammal survey to collect systematic visual data and acoustic 
information on the distribution and abundance of marine mammals in the 
Chukchi Sea during the 2006 open water season. The MV Torsvik (or 
another vessel, depending upon its capability to tow the passive 
acoustic array) will be used for these surveys. Visual observations 
will be made by two teams of three observers each following standard 
marine mammal ship survey line transect procedures. Acoustic data will 
be collected using a towed hydrophone passive acoustic monitoring (PAM) 
equipment. The PAM will be monitored in real time by an acoustics 
technician and continuous recordings will be made during all on-effort 
periods.
    Three dedicated marine mammal surveys will be conducted during the 
course of the open-water period. During each of these dedicated 
surveys, a systematic survey route composed of ten, 50 nm (92 km) line 
transects (in a saw-toothed pattern) will be run by the vessel 
(weather, ice and logistics permitting). The transect line has been 
designed to be covered in approximately 3 days of surveying. The start 
of the survey route will be randomly selected from within a 10 nm (19 
km) area and the entire survey line shifted based on that start 
location. The survey route has been designed to cover a large portion 
of the Outer Continental Shelf (OCS) Chukchi Sea lease sale area and 
remain in waters of similar depths. The three surveys are scheduled to 
occur in early July, mid-August, and mid-October. By repeating nearly 
the same route during each survey, seasonal differences in sighting 
rates and densities may be more readily detected. In addition to 
dedicated marine mammal surveys, whenever Shell, Conoco and/or GXT's 
seismic vessel is conducting surveys in an area too distant for safe 
aerial surveys during the fall bowhead migration in the fall, the M/V 
Torsvik (or another similar vessel) will undertake surveys to look for 
bowhead cow/calf pairs within the upcurrent portion of the area 
delineated by the 120 dB isopleth of the vessel's seismic array (see 
Mitigation).
Passive Acoustic Monitoring
    A towed hydrophone array will be used to monitor for vocalizing 
marine mammals during the dedicated marine mammal surveys. The array 
will contain two hydrophone elements designed to receive sounds in 
approximately the 100-Hz to 45-kHz range. This range covers the 
frequency of calls known to be produced by cetaceans and pinnipeds 
likely to be encountered in the Chukchi Sea during the open-water 
season (gray and bowhead whales

[[Page 43131]]

ranging from 100 Hz-4 kHz; beluga whales ranging up to approximately 10 
kHz; pinnipeds ranging up to 5 kHz). The hydrophone array will be 
monitored during all daylight hours during the research portion of the 
survey and day and night during the mitigation phase (as mentioned 
above and later in this document). One bioacoustician will be required 
during the research phase and two or more during the mitigation phase 
if seismic vessels operate outside the zone for safe and effective 
aerial monitoring. Information on operations of the PAM can be found in 
LGL's Marine Mammal Monitoring, Mitigation, and Investigatory Plan (2006).
Acoustic Net Array
    In addition to using PAM onboard the dedicated research vessel, an 
acoustic ``net'' array has been designed and will be deployed along the 
Chukchi Sea coast to collect information on the occurrence and 
distribution of beluga, and possibly bowhead whales that may be 
available to subsistence hunters near coastal villages. A suite of 
autonomous seafloor recorders (pop-ups) will be deployed by the 
industry to collect acoustic data from strategically situated sites in 
the Chukchi Sea. The basic plan will be to deploy horizontal line 
arrays (HLA) of pop-ups in four areas from approximately Pt. Hope to 
the western Beaufort Sea east of Barrow, Alaska. Each of the four HLAs 
will contain 4 pop-ups separated by approximately 6-8 nm (11-15 km) so 
as to have an end-to-end length of approximately 18-24 nm (33-44 km) 
thus forming an inshore-to-offshore ``net.'' An additional 4 pop-ups 
will be deployed at sites about 50-75 nm (92-139 km) offshore. The 
specific geometries and placements of the arrays are primarily driven 
by the objectives of (1) detecting the occurrence and approximate 
offshore distributions of beluga and possibly bowhead whales during the 
July to mid-August period and primarily bowhead whales during the mid-
August to late October period, (2) measuring ambient noise, and (3) 
measuring received levels of seismic survey activities. Timing of 
deployment, number of pop-ups, and final positions will be subject to 
equipment availability, weather and ice conditions, and consultation 
with local villages so as to not interfere with subsistence hunting or 
fishing activities.

Reporting

    Conoco will submit a report to NMFS approximately 90 days after 
completion of the 2006 season. The 90-day report will: (1) present the 
results of the 2006 shipboard marine mammal monitoring; (2) estimate 
exposure of marine mammals to industry sounds; (3) provide data on 
marine mammal sightings (e.g., species, numbers, locations, age/size/
gender, environmental correlates); (4) analyze the effects of seismic 
operations (e.g., on sighting rates, sighting distances, behaviors, 
movement patterns); (5) provide summaries of power downs, shut downs, 
and ramp up delays; (6) provide an analysis of factors influencing 
detectability of marine mammals; (7) provide summaries on 
communications with hunters and potential effects on subsistence 
activities; and (8) present the results of the field verification of 
the safety radii.
    Following the 2006 open water season, Conoco, Shell, and GXT will 
submit a single comprehensive report describing the acoustic, vessel-
based, and aerial monitoring programs for all industrial seismic 
programs covered by IHAs will be prepared. This comprehensive report 
will describe the methods, results, conclusions and limitations of each 
of the individual data sets in detail. The report will also integrate 
(to the extent possible) the studies into a broad based assessment of 
industry activities and their impacts on marine mammals in the Chukchi 
Sea during 2006. The report will help to establish long term data sets 
that can assist with the evaluation of changes in the Chukchi Sea 
ecosystem. The report will also incorporate studies being conducted in 
the Beaufort Sea and will attempt to provide a regional synthesis of 
available data on industry activity in offshore areas of northern 
Alaska that may influence marine mammal density, distribution and behavior.
    This comprehensive report will consider data from many different 
sources including two relatively different types of aerial surveys; 
several types of acoustic systems for data collection (net array, PAM, 
and Ocean Bottom Hydrophone systems), and vessel based observations. 
Collection of comparable data across the wide array of programs will 
help with the synthesis of information. However, interpretation of 
broad patterns in data from a single year is inherently limited. Many 
of the 2006 data will be used to assess the efficacy of the various 
data collection methods and to help establish protocols that will 
provide a basis for integration of the data sets over a period of 
years. Because of the complexity of this comprehensive report, NMFS is 
requiring that this report be submitted in draft to NMFS by April 1, 
2007, in order for consideration, review and comment at the 2007 open 
water meeting prior to completion of a final comprehensive report.

Endangered Species Act

    NMFS has issued a biological opinion regarding the effects of this 
action (among others) on ESA-listed species and critical habitat under 
the jurisdiction of NMFS. That biological opinion concluded that this 
action is not likely to jeopardize the continued existence of listed 
species or result in the destruction or adverse modification of 
critical habitat. A copy of the Biological Opinion is available upon 
request (see ADDRESSES).

National Environmental Policy Act (NEPA)

    The MMS prepared a Draft PEA for the 2006 Arctic Outer Continental 
Shelf (OCS) Seismic Surveys. NMFS was a cooperating agency in the 
preparation of the MMS Draft and Final PEAs. NMFS noted that the MMS 
had prepared a PEA for the 2006 Arctic seismic surveys and made this 
Draft PEA available upon request (71 FR 26055, May 3, 2006). In 
accordance with NOAA Administrative Order 216-6 (Environmental Review 
Procedures for Implementing the National Environmental Policy Act, May 
20, 1999), NMFS has determined that the MMS Final PEA contains an in-
depth and detailed description of the seismic survey activities, 
reasonable alternatives to the proposed action, the affected 
environment, mitigation and monitoring measures identified to reduce 
impacts on the human environment to non-significant levels, and the 
potential effects of the action on the human environment. In view of 
the information presented in this document and the analysis contained 
in the supporting PEA, NMFS has determined therefore that issuance by 
NMFS of an IHA to Conoco and other companies for conducting seismic 
surveys this year in the Arctic Ocean will not significantly impact the 
quality of the human environment as described above and in the 
supporting Final PEA and hereby adopts MMS' final PEA. Therefore, an 
Environmental Impact Statement is not necessary.
    A determination of non-significance is predicated however on full 
implementation of standard mitigation measures for preventing injury or 
mortality to marine mammals, in addition to area specific mitigation 
measures, such as implementation of (1) a 120-dB rms monitoring-safety 
zone for cow/calf pairs of bowhead whales in the Beaufort and Chukchi 
seas; (2) a 160-dB rms monitoring-safety zone for aggregations of 
feeding bowheads and gray whales in the Beaufort and

[[Page 43132]]

Chukchi seas; (3) seismic shut-down criteria to protect bowhead and 
gray whales when inside the 120-dB or 160-dB monitoring-safety zones; 
and (4) a joint industry cooperative program on marine mammal research 
in the Chukchi Sea. A copy of the MMS Final PEA for this activity is 
available upon request and is available online (see ADDRESSES).

Preliminary Conclusions

Summary

    Based on the information provided in Conoco's application and the 
MMS PEA, and dependent upon the implementation of the required 
mitigation and monitoring measures, NMFS has determined that the impact 
of Conoco conducting seismic surveys in the northeastern Chukchi Sea in 
2006 will have a negligible impact on marine mammals and that there 
will not be any unmitigable adverse impacts to subsistence communities, 
provided the mitigation measures required under the authorization are 
implemented and a CAA is implemented.

Potential Impacts on Marine Mammals

    NMFS has preliminarily determined that the relatively short-term 
impact of conducting seismic surveys in the U.S. Chukchi Sea may 
result, at worst, in a temporary modification in behavior by small 
numbers of certain species of marine mammals and/or low-level 
physiological effects (Level B Harassment). While behavioral and 
avoidance reactions may be made by these species in response to the 
resultant noise, this behavioral change is expected to have a 
negligible impact on the affected species and stocks of marine mammals.
    While the number of potential incidental harassment takes will 
depend on the distribution and abundance of marine mammals (which vary 
annually due to variable ice conditions and other factors) in the area 
of seismic operations, the number of potential harassment takings is 
estimated to be relatively small in light of the population size (see 
Table 1). NMFS anticipates the actual take of individuals to be lower 
than the numbers depicted in the table because those numbers do not 
reflect either the implementation of the mitigation numbers or the fact 
that some animals will avoid the the sound at levels lower than those 
expected to result in harassment. Additionally, for both ringed seals 
and bearded seals, the abundance estimates used to calculate the 
percentages only represent part of the population (which means the 
estimated percentages are further over estimates). Further, for ringed 
seals, the numbers are even lower because the density used for the 
calculation did not account for the fact that ringed seals are much 
denser near the shore and ice than they are in the open ocean where the 
seismic survey is primarily being conducted.
    In addition, no take by death and/or serious injury is anticipated, 
and the potential for temporary or permanent hearing impairment will be 
avoided through the incorporation of the required mitigation measures 
described in this document. This determination is supported by (1) the 
likelihood that, given sufficient notice through slow ship speed and 
ramp-up of the seismic array, marine mammals are expected to move away 
from a noise source that it is annoying prior to its becoming 
potentially injurious; (2) TTS is unlikely until levels above 180 dB re 
1 microPa are reached; (3) the fact that injurious levels of sound are 
only likely very close to the vessel; and (4) the likelihood that 
marine mammal detection ability by trained observers is close to 100 
percent during daytime and remains high at night close to the vessel.
    Finally, aside from the migration pathway (which has been addressed 
in this document) no known rookeries, mating grounds, areas of 
concentrated feeding, or other areas of special significance for marine 
mammals are known to occur within or near the planned areas of 
operations during the season of operations.

Potential Impacts on Subsistence Uses of Marine Mammals

    NMFS believes that the seismic activity by Conoco in the northern 
Chukchi Sea in 2006 will not have an unmitigable adverse impact on the 
subsistence uses of bowhead whales and other marine mammals. This 
determination is supported by the following: (1) Seismic activities in 
the Chukchi Sea will not begin until after July 10 by which time the 
spring bowhead hunt is expected to have ended; (2) the fall bowhead 
whale hunt in the Beaufort Sea will be governed by a CAA between Conoco 
and the AEWC and village whaling captains, which includes conditions 
that will significantly reduce impacts on subsistence uses; (4) while 
it is possible, but unlikely, that accessibility to belugas during the 
spring subsistence beluga hunt could be impaired by the survey, very 
little of the planned survey is within 25 km (15.5 mi) of the Chukchi 
coast, meaning the vessel will usually be well offshore away from areas 
where seismic surveys would influence beluga hunting by communities; 
and (5) because seals (ringed, spotted, bearded) are hunted in 
nearshore waters and the seismic survey will remain offshore of the 
coastal and nearshore areas of these seals, it should not conflict with 
harvest activities.

Authorization

    As a result of these preliminary determinations, NMFS has issued an 
IHA to Conoco for conducting a seismic survey in the northern Chukchi 
Sea in 2006, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated.

    Dated: July 7, 2006.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries Service.
[FR Doc. 06-6584 Filed 7-28-06; 8:45 am]
BILLING CODE 3510-22-C 

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